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West African flood-plains have undergone major land-use transformations in the second half of the 20th century. To obtain insight in the effect of flood-plain development for irrigated rice cultivation on the abundance, richness, and diversity of Palearctic and Afrotropical raptors, we conducted. From frog integument to human skin: dermatological perspectives from frog skin biology.

Haslam, I. For over a century, frogs have been studied across various scientific fields, including physiology, embryology, neuroscience, neuro endocrinology, ecology, genetics, behavioural science, evolution, drug development, and conservation biology. In some cases, frog skin has proven very successful as a. Effects of the herbicide imazapyr on juvenile Oregon spotted frogs. Conflict between native amphibians and aquatic weed management in the Pacific Northwest is rarely recognized because most native stillwater-breeding amphibian species move upland during summer, when herbicide application to control weeds in aquatic habitats typically occurs.

However, aquatic weed management may pose a risk for aquatic species present in wetlands through the summer, such as the Oregon spotted frog OSF, Rana pretiosa , a state endangered species in Washington. Acute toxicity of herbicides used to control aquatic weeds tends to be low, but the direct effects of herbicide tank mixes on OSFs have remained unexamined. We exposed juvenile OSFs to tank mixes of the herbicide imazapyr, a surfactant, and a marker dye in a h static-renewal test. The tank mix was chosen because of its low toxicity to fish and its effectiveness in aquatic weed control.

Concentrations were those associated with low-volume 3. Following exposure, frogs were reared for two months in clean water to identify potential latent effects on growth. Endpoints evaluated included feeding behavior, growth, and body and liver condition indices. We recorded no mortalities and found no significant differences for any end point between the herbicide-exposed and clean- water control frogs.

The results suggest that imazapyr use in wetland restoration poses a low risk of direct toxic effects on juvenile OSFs. Snoring puddle frog. Full text: The purpose of this paper is to hold a biological mirror in front of ourselves, the nuclear energy community, and to suggest that the reflection we will see there will help us both professionally and as members of a broader society. Let us start with sex. For sex to function as a means of reproduction, a male and a female of a particular species have to recognise each other and mate.

The important terms here are 'particular species' and 'recognise'. Within most species, extraordinarily precise mate recognition systems have evolved. The precise frequency of the croak of a particular species of frog ; the precise seasonal coloration of a particular species of salmon; the precise length of the tail of a particular species of bird; each is recognisable instantly to a prospective mate, though not to untrained human ears or eyes.

Its author, HEH Paterson, suggests that a species can be defined as a group of organisms that share a common mate recognition system. Mating is an exchange of genes, and creatures that do not recognise each other do not exchange genes. A mate recognition system closes off the gene pool and may increasingly isolate its participants from even their nearest relatives. Biological evolution has numerous links and parallels with the evolution of human cultures. Some of our recognition systems seem to have a knack for drawing everyone in - American popular culture, for example, is now inescapable.

Other recognition systems repel all but a few - take, or rather don't take, the Hell's Angels or the Ku Klux Klan. We, as members of the nuclear energy culture, are members of a closed and even repellent gene pool. We share a recognition system by which we perpetuate ourselves from generation to generation, from Hiroshima to Chernobyl.

Outsiders do not understand our language: terms like 'credit for fission products. Effects of acute exposure to magnetic field on ionic composition of frog sciatic nerve. Objective: To evaluate the possible interaction between magnetic field and cadmium on ionic composition of frog sciatic nerve.

Design: The combined effect of magnetic field and cadmium 1. Sciatic nerve samples were extracted, weighed and mixed in bidistilled water in order to analyze by inductively coupled plasma ICP ionic composition. Magnetic field magnifies the effect of cadmium on calcium homeostasis. Full Text Available Background: There has been increasing awareness throughout the world regarding the remarkable decrease in amphibian population.

For such amphibian population decline several causes have been given. Cadmium, a heavy metal is released both from natural sources leaching of cadmium rich soils and anthropogenic activities to the aquatic and terrestrial environments. This study evaluated the toxicity of heavy metal cadmium to Indian skipper frog Rana cyanophlyctis. Methods: For the determination of LC50 values for cadmium, four-day static renewal acute toxicity test was used. Results: The LC50 values of cadmium chloride for the frog R.

The results have been discussed with the toxicity reported for other aquatic vertebrate --fish. Conclusion: Cadmium caused mortality to the frog and this could be one of the reasons for population decline of frogs which inhabit water contaminated with heavy metals. Effect of cattle exclosures on Columbia Spotted Frog abundance.

Adams, Michael J. Livestock grazing is an important land use in the western USA and can have positive or negative effects on amphibians. Columbia Spotted Frog Rana luteiventris often use ponds that provide water for cattle. We conducted a long-term manipulative study on US Forest Service land in northeastern Oregon to determine the effects of full and partial exclosures that limited cattle access to ponds used by frogs. We found weak evidence of a short-term increase in abundance that did not differ between full and partial exclosures and that diminished with continuing exclusion of cattle.

The benefit of exclosures was small relative to the overall decline in breeding numbers that we documented. This suggests that some protection can provide a short-term boost to populations. Pesticide concentrations in frog tissue and wetland habitats in a landscape dominated by agriculture.

Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations.

We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata chorus frogs and Lithobates pipiens leopard frogs at six wetlands 3 restored and 3 reference in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources.

Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations.

Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs , possibly because of differences in life histories.

Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and implementing. Pesticide concentrations in frog tissue and wetland habitats in alandscape dominated by agriculture. Smalling, Kelly L. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and.

Oregon spotted frogs breed in shallow pools in cm deep that are near flowing water , or Friesz , p. They are laid in shallow, often temporary, pools of water ; gradually receding Eleutherodactylus frog introductions to Hawaii. As an oceanic archipelago isolated from continental source areas, Hawaii lacks native terrestrial reptiles and amphibians, Polynesians apparently introduced seven gecko and skink species after discovering the islands approximately years ago, and another 15 reptiles and five frogs have been introduced in the last century and a half McKeown The Polynesian introductions are probably inadvertent because the species involved are known stowaway dispersers Gibbons ; Dye and Steadman , In contrast, most of the herpetological introductions since European contact with Hawaii have been intentional.

Several frog species were released for biocontrol of insects e. Neuromuscular control of prey capture in frogs. While retaining a feeding apparatus that is surprisingly conservative morphologically, frogs as a group exhibit great variability in the biomechanics of tongue protraction during prey capture, which in turn is related to differences in neuromuscular control.

In this paper, I address the following three questions. Prey specialization and diet of frogs in Borneo. Earlier studies of the diet of frogs indicate that most adult frogs are mainly insectivorous. Overall, frogs are viewed more as generalists than specialists in terms of their diet.

However, despite earlier studies, there are still gaps in our knowledge regarding what frogs tend to eat and the degree of specialization. The aim of this study was to investigate the diet choice of frogs in a tropical ecosystem. The present study was conducted in a well-known hotspot for frogs with 66 of the k Full Text Available Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy.

Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata.

We artificially dried ferns of various sizes to identify relationships between water and temperature buffering. Ferns are the preferred diurnal microhabitat and breeding habitat for arboreal frogs. A strong positive relationship exists between fern size and frog usage and abundance. Our drying experiments show that large ferns buffer maximum temperatures and reduce variability in temperatures, and buffering is directly linked to their hydration.

Frogs are likely using large ferns for their moist, cool, environments for breeding and daytime retreat, which supports the buffered microhabitat hypothesis—these plants promote species coexistence through habitat creation and amelioration of physical stress. However, drying experiments suggest that this buffering is contingent on regular rainfall. Altered rainfall regimes could lead to the unexpected loss of the functional capacity of these important fern habitats.

The Lake Titicaca frog Telmatobius culeus is critically endangered, primarily from overexploitation. However, additional threats, such as chytrid fungus Batrachochytrium dendrobatidis , are poorly studied. We found moderate levels of chytrid infection using quantitative PCR. Our results enhance our understanding of chytrid tolerance to high pH and low water temperature. Migration through the Eastern Palearctic EP flyway by tundra swans Cygnus columbianus has not been thoroughly documented.

We satellite-tracked the migration of 16 tundra swans that winter in Japan. The objectives of this study were 1 to show the migration pattern of the EP flyway of tundra swans; 2 to compare this pattern with the migration pattern of whooper swans; and 3 to identify stopover sites that are important for these swans' conservation. Tundra swans were captured at Kutcharo Lake, Hokkaido, in and satellite-tracked. Based on median, the spring migration began on 18 April and ended on 27 May.

Autumn migration began on 9 September and ended on 2 November. The median duration of the spring and autumn migrations were 48 and 50 days, respectively. The mean duration at one stopover site was 5. The number of stopover sites was 3. The mean travel distances for the spring and autumn migrations were and km, respectively. There were 15, 32, and eight wintering, stopover, and breeding sites, respectively.

The migration routes and staging areas of tundra swans partially overlap with those of whooper swans, whose migration patterns have been previously documented. Pesticides are receiving increasing attention as potential causes of amphibian declines, acting singly or in combination with other stressors, but limited information is available on the accumulation of current-use pesticides in tissue.

The authors examined potential exposure and accumulation of currently used pesticides in pond-breeding frogs Pseudacris regilla collected from 7 high elevations sites in northern California. Whole frog tissue, water , and sediment were analyzed for more than 90 current-use pesticides and pesticide degradates using gas chromatography—mass spectrometry. Two fungicides, pyraclostrobin and tebuconazole, and one herbicide, simazine, were the most frequently detected pesticides in tissue samples.

Tebuconazole and pyraclostrobin were the only 2 compounds observed frequently in frog tissue and sediment. Significant spatial differences in tissue concentration were observed, which corresponded to pesticide use in the upwind counties. Data generated indicated that amphibians residing in remote locations are exposed to and capable of accumulating current-use pesticides.

A comparison of P. We describe a new type of co-orbital resonance that can explain the observed non-Keplerian motions of propellers. The resonance is between the moonlet underlying the propeller and co-orbiting ring particles downstream of the moonlet where the gap closes. The moonlet librates within the gap about an equilibrium point established by co-orbiting material and stabilized by the Coriolis force. In the limit of small libration amplitude, the libration period scales linearly with the gap azimuthal width and inversely as the square root of the co-orbital mass.

The new resonance recalls but is distinct from conventional horseshoe and tadpole orbits; we call it the ' frog ' resonance, after the relevant term in equine hoof anatomy. These librations should be subtracted from the longitude data before any inferences about moonlet migration are made.

Regulation of 5'-adenosine monophosphate deaminase in the freeze tolerant wood frog , Rana sylvatica. Frozen frogs exhibit no vital signs and their organs must endure multiple stresses, particularly long term anoxia and ischemia. Maintenance of cellular energy supply is critical to viability in the frozen state and in skeletal muscle, AMP deaminase AMPD plays a key role in stabilizing cellular energetics. The present study investigated AMPD control in wood frog muscle.

Wood frog AMPD was subject to multiple regulatory controls: binding to subcellular structures, protein phosphorylation, and effects of allosteric effectors, cryoprotectants and temperature. AMPD was a target of protein phosphorylation. ATP and Mg. ADP and inhibited by Mg. The enzyme product, IMP, uniquely inhibited only the bound phosphorylated enzyme from muscle of frozen frogs.

Activators and inhibitors differentially affected the free versus bound enzyme. Birds and frogs in mathematics and physics. Some scientists are birds, others are frogs. Birds fly high in the air and survey broad vistas of mathematics out to the far horizon. They delight in concepts that unify our thinking and bring together diverse problems from different parts of the landscape.

Frogs live in the mud below and see only the flowers that grow nearby. They delight in the details of particular objects, and they solve problems one at a time. A brief history of mathematics and its applications in physics is presented in this article. Hematophagous insects as vectors for frog trypanosomes. Experimental infections of three hematophagous arthropods Rhodnius prolixus, Aedes aegypti, and Culex pipiens with a trypanosome of the Trypanosoma rotatorium complex found in the frogs Hyla crepitans and Leptodactylus insularum revealed that A.

It is postulated that, in addition to the transmission of T. Differential uptake of gold nanoparticles by 2 species of tadpole, the wood frog Lithobates sylvaticus and the bullfrog Lithobates catesbeianus. Engineered nanoparticles are aquatic contaminants of emerging concern that exert ecotoxicological effects on a wide variety of organisms. Wood frog tadpoles alone and in combination with bullfrog tadpoles took up significantly more gold than bullfrogs.

Bullfrog tadpoles in combination with wood frogs took up significantly more gold than controls. In all gold-exposed groups of tadpoles, gold was concentrated in the anterior region compared with the posterior region of the body. The concentration of gold nanoparticles in the anterior region of wood frogs both alone and in combination with bullfrogs was significantly higher than the corresponding posterior regions.

We also measured depuration time of gold in wood frogs. Our finding of differential uptake between closely related species living in similar habitats with overlapping geographical distributions argues against generalizing toxicological effects of nanoparticles for a large group of organisms based on measurements in only one species.

Environ Toxicol Chem ; Pseudacris triseriata western chorus frog and Rana sylvatica wood frog chytridiomycosis. The chytrid fungus Batrachochytrium dendrobatidis is a known pathogen of anuran amphibians, and has been correlated with amphibian die-offs worldwide Daszak et. Emerging Infectious Diseases In Colorado, B. We report the first verified case of chytrid fungus in chorus frogs Pseudacris triseriata and wood frogs Rana sylvatica in the United States. We collected seven P.

Chorus frogs were shipped in one container. Wood frog adults and juveniles were shipped in two separate containers. Histological examinations of all chorus frogs and 3 of 4 wood frogs were positive for chytrid fungus infection. The fourth adult wood frog was too decomposed for meaningful histology. Histological findings consisted of multifocally mild to diffusely severe infections of the epidermis of the ventrum and hindlimb digital skin.

Chytrid thalli were confined to the thickened epidermis hyperkeratosis , were spherical to oval, and occasional thalli contained characteristic discharge pores or zoospores Green and Kagarise Sherman Herpetol ; Fellers et al. Copeia We cannot confirm that all specimens carried the fungus at collection, because infection may have spread from one individual to all other individuals in each container during transport.

Further sampling of amphibians in Kawuneeche Valley is warranted to determine the rate of infection and mortality in these populations. Evolutionary dynamics across discontinuous freshwater systems: Rapid expansions and repeated allopolyploid origins in the Palearctic white water -lilies Nymphaea.

Postglacial climate changes and rise of three ecotypes of harbour porpoises, Phocoena phocoena, in western Palearctic waters. Despite no obvious barriers to gene flow in the marine realm, environmental variation and ecological specializations can lead to genetic differentiation in highly mobile predators. Here, we investigated the genetic structure of the harbour porpoise over the entire species distribution range in. Of volcanoes, saints, trash, and frogs. During one year of ethnographic fieldwork volcanoes, saints, trash and frogs were among the nonhuman entities referred to in conversations and engaged with when responding to the changes that trouble the world and everyday life of Arequipans A common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species.

For Columbia spotted frogs Rana luteiventris in the Great Basin USA , a genetically distinct population segment of conservation concern, we approached this problem by examining 1 landscape-scale habitat availability and distribution, 2 water body-scale habitat associations, and 3 resource management-identified threats to persistence. We found that areas with perennial aquatic habitat and suitable climate are extremely limited in the southern portion of the species' range.

Within these suitable areas, native and non-native predators trout and American bullfrogs [Lithobates catesbeianus] are widespread and may further limit habitat availability in upper- and lower-elevation areas, respectively.

At the water body scale, spotted frog occupancy was associated with deeper sites containing abundant emergent vegetation and nontrout fish species. Streams with American beaver Castor canadensis frequently had these structural characteristics and were significantly more likely to be occupied than ponds, lakes, streams without beaver, or streams with inactive beaver ponds, highlighting the importance of active manipulation of stream environments by beaver.

Native and non-native trout reduced the likelihood of spotted frog occupancy, especially where emergent vegetation cover was sparse. Intensive livestock grazing, low aquatic connectivity, and ephemeral hydroperiods were also negatively associated with spotted frog occupancy.

We conclude that persistence of this species at the arid end of its range has been largely facilitated by habitat stability i. Use of olfactory cues by newly metamorphosed wood frogs Lithobates sylvaticus during emigration. Juvenile amphibians are capable of long-distance upland movements, yet cues used for orientation during upland movements are poorly understood.

We used newly metamorphosed Wood Frogs Lithobates sylvaticus to investigate: 1 the existence of innate i. In a circular arena experiment, animals with assumed innate directionality did not orient in the expected direction suggested by previous studies when deprived of visual and olfactory cues. This suggests that juvenile Wood Frogs most likely rely on proximate cues for orientation. This finding is contrary to known habitat use by adult Wood Frogs during summer.

Juvenile Wood Frogs were indifferent to the chemical signature of natal pond cattle tank water. Our findings suggest that management strategies for forest amphibians should consider key habitat features that potentially influence the orientation of juveniles during emigration movements, as well as adult behavior. Trichobothrial mediation of an aquatic escape response: Directional jumps by the fishing spider, Dolomedes triton, foil frog attacks.

Full Text Available Fishing spiders Pisauridae frequent the surfaces of ponds and streams and thereby expose themselves to predation by a variety of aquatic and semi-aquatic vertebrates. To assess the possibility that the impressive jumps of fishing spiders from the water surface function in evading attacks by frogs , attacks by bullfrogs Rana catesbiana and green frogs R.

Both the attack dynamics of the frogs and the evasive behaviors of the spiders were recorded at frames per second. A freeze-dried bullfrog, propelled toward spiders with acceleration, posture, and position that approximated the natural attack posture and dynamics, was used to assess the spiders' behavior.

The involvement of the trichobothria leg hairs sensitive to air movements, and the eyes as sensory mediators of the evasion response was assessed. Spiders with deactivated trichobothria were significantly impaired relative to intact and sham-deactivated spiders, and relative to spiders in total darkness. Thus, functional trichobothria, unlike the eyes, are both necessary and sufficient mediators of the evasion response.

Measurements of air flow during frog attacks suggest that an exponential rise in flow velocity is the airborne signature of an attack. Big mountains but small barriers: population genetic structure of the Chinese wood frog Rana chensinensis in the Tsinling and Daba Mountain region of northern China. Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns.

Numerous studies have suggested that genetic differentiation among amphibian populations are particularly pronounced for populations separated by mountain ridges. The Tsinling Mountain range of northern China is a major mountain chain that forms the boundary between the Oriental and Palearctic zoogeographic realms. We studied the population structure of the Chinese wood frog Rana chensinensis to test whether the Tsinling Mountains and the nearby Daba Mountains impose major barriers to gene flow.

Using 13 polymorphic microsatellite DNA loci, individuals from 12 breeding sites with geographical distances ranging from 2. Substantial genetic diversity was detected at all sites with an average of In addition, the genetic differentiation among the central populations was statistically significant, with pairwise FST values ranging from 0. Furthermore, hierarchical AMOVA analysis attributed most genetic variation to the within-population component, and the between-population variation can largely be explained by isolation-by-distance.

None of the putative barriers detected from genetic data coincided with the location of the Tsinling Mountains. The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R. High population connectivity and extensive juvenile dispersal may account for the significant, but moderate differentiation between populations.

Chinese wood frogs are able to use streams as breeding sites at high elevations, which may significantly contribute to the. Big mountains but small barriers: Population genetic structure of the Chinese wood frog Rana chensinensis in the Tsinling and Daba Mountain region of northern China. Full Text Available Abstract Background Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns.

Results Using 13 polymorphic microsatellite DNA loci, individuals from 12 breeding sites with geographical distances ranging from 2. Conclusion The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R.

Chinese wood frogs are able to use streams as breeding sites at high. Full Text Available Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape. In Brazil's Atlantic Forest, we evaluated frog richness and abundance by breeding guild at four distances from the edge of a reserve: i m inside the forest, ii 50 m inside the forest, iii at the forest edge, and iv 50 m inside three different converted habitats coffee plantation, non-native Eucalyptus plantation, and abandoned pastures, hereafter matrix types.

By sampling a dry and a wet season, we recorded individual frogs representing 29 species, of which three were undescribed. Breeding guild i. Leaf-litter and bromeliad breeders decreased in richness and abundance from the forest interior toward the matrix habitats.

Water -body breeders increased in richness toward the matrix and remained relatively stable in abundance across distances. Number of large trees i. Twenty species found in the interior of the forest were not found in any matrix habitat. Richness and abundance across breeding guilds were higher in the rainy season but frog distributions were similar across the four distances in the two seasons. Across matrix types, leaf-litter species primarily used Eucalyptus plantations, whereas water -body species primarily used coffee plantations.

Bromeliad breeders were not found inside any matrix habitat. Our study highlights the importance of primary forest for bromeliad and leaf-litter breeders. We propose that water -body breeders use edge and matrix habitats to reach breeding habitats along the valleys. Including life-history characteristics, such as breeding guild, can improve predictions of frog.

Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape. Including life-history characteristics, such as breeding guild, can improve predictions of frog distributions in. Large intestine bacterial flora of nonhibernating and hibernating leopard frogs Rana pipiens.

The bacteria in the large intestines of 10 northern leopard frogs Rana pipiens were enumerated and partially characterized. Four nonhibernating frogs were collected in the summer, four hibernating frogs were collected in the winter, and two frogs just emerged from hibernation were collected in the spring. All frogs had about 10 10 bacteria per g wet weight of intestinal contents and about 10 9 bacteria per g wet weight of mucosal scraping, although the counts from the winter frogs wer Terrestrial activity and conservation of adult California red-legged frogs Rana aurora draytonii in coastal forests and grasslands.

The federally threatened California red-legged frog Rana aurora draytonii occupies both aquatic and terrestrial habitats in its adult life stage. The terrestrial activities of this species are not well known and require documentation to assist in the development of appropriate levels of protection under the US Endangered Species Act.

In particular, we investigated 1 the use of terrestrial habitats by non-migrating adults in relation to season, breeding chronology, and precipitation, and 2 adult migration behavior, including seasonal timing, duration, distances traveled, and the use of corridors.

All of the non-migrating frogs remained within m of their aquatic site of residence median days , despite frequent and copious rainfall. Adult migration to and from breeding sites occurred from late October through mid-May wet season. We monitored 25 migration events between aquatic sites that were m apart. Short distance movements days, longer movements required up to 2 months.

Most migrating frogs moved overland in approximately straight lines to target sites without apparent regard to vegetation type or topography. Riparian corridors were neither essential nor preferred as migration routes. Frogs traveling overland occurred in upland habitats as far as m from water. Adequate protection of red-legged frog populations inhabiting.

Apomorphine effects on frog locomotor behavior. The neuroanatomical pathways of the DA systems have been shown to be largely conserved across many vertebrate taxa. It is less certain whether the structural similarities seen between mammals and amphibians reflect a similar functional homology. DA is well known for its role in facilitating motor behaviors in mammals. We investigated the effects of the nonspecific DA agonist, apomorp Vocal competition in male Xenopus laevis frogs.

Male Xenopus laevis frogs produce underwater advertisement calls that attract gravid females and suppress calling by male competitors. Here we explore whether groups of males establish vocal ranks and whether auditory cues alone suffice for vocal suppression.

Tests of male—male pairs within assigned groups reveal linear vocal dominance relations, in which each male has a defined rank. Both the duration over which males interact, as well as the number of competitive opportunities, affect linea Cellular mechanisms of nociception in the frog. Biogeographic patterns of Colombian frogs and toads.

Using the data provided in Ruiz-Carranza et al. Some lowlands areas pacific lowlands, Amazonian exhibit high diversity species but lowlands areas in general are impoverished species , especially when contrasted with upland areas. The three Andean cordilleras harbor between 87 and species of frogs and toads, demonstrating that the biodiversity of Colombia resides primarily in its montane components, not in its lowland rain forests.

When biological endemicity is separated from political endemicity, five areas of high endemicity remain the three Andean cordilleras, the Sierra Nevada de Santa Marta, and the pacific lowlands. We endeavor to explain this description by recourse to cladistic analyses of several groups of leptodactylid frogs where we find that the general pattern of diversification is by means of horizontal diversification allopatric speciation with a minor contribution from vertical diversification.

Full Text Available The frogs of the Federal District of Brazil are listed and discussed as to habit, biology and ecology. The F. Its topography includes sea-shore, maritime scrub, lagoons, plains and marsh, open slopes, forested mountains and great heads of rock. Three thousand feet of altitude are attained at two points. Fifty two different frogs occur in the F.

Three fifths of them live in open country. Two fifths of these have never been found above the plains; the others range higher but mostly in open country. Their environment offers conditions suitable for average tadpoles and adults. There are six genera and thirty species.

Two thirds of the latter belong to the type genera of the large neotropical families Bufonidae, Leptodactylidae and Hylidae. Only in the maritime scrub formation are conditions somewhat different. Water for average tadpoles is provided by the lagoons. The xerophytism of the vegetation is, however, so marked that bromeliads growing on the ground provide almost the only appropriate shelter for adult tree- frogs used to sleeping upright on the vegetation.

One large Hylid genus lives entirely in them. It is casque-headed and phragmotic, shutting the lumen of the leaf-cup with head used as a plug. Another large Hylid genus shows a lesser degree of the same specialization.

One genus with two species is entirely saxicolous; it lives on wet ledges of rock at all phases of its life history. Lutz The other two fifths of the frogs from F. Their environment offers numerous and varied biotopes and is near optimum for adults. There is,however, hardly any standing water available for larvae. These frogs are ecologically diversified. They also show a general trend towards spawning in the adult biotipe, which leads to delayed hatching, semi-aquatic and terrestrial.

Assessment of frog meat utilisation in Ibadan, Oyo state, Nigeria Frogs are among the most threatened species of wildlife in IUCN red list. Its utilisation in Ibadan, a major depot in western Nigeria was therefore conducted with the aim of assessing the forms and trend of use; and amongst others, reasons for frog meat consumption. Data for the study were collected through questionnaire, Modeling potential river management conflicts between frogs and salmonids.

Steven F. Railsback; Bret C. Harvey; Sarah J. Kupferberg; Margaret M. Management of regulated rivers for yellow-legged frogs Rana boylii and salmonids exemplifies potential conflicts among species adapted to different parts of the natural flow and temperature regimes. Yellow-legged frogs oviposit in rivers in spring and depend on declining flows and warming temperatures for egg and tadpole survival and growth, A simple and inexpensive method of monitoring the movement of an isolated frog heart provides comparable results to those obtained with a force transducer.

A commercially available photoresistor is integrated into a Wheatstone bridge circuit, and the output signal is interfaced directly with a recording device. An excised, beating frog heart is…. Endocrine-disrupting effects and reproductive toxicity of low dose MCLR on male frogs Rana nigromaculata in vivo. However, MCLR concentrations in several water bodies have exceeded this level. Despite this recommended human safety standard, MCLR-induced endocrine-disrupting effects and reproductive toxicity on male frog Rana nigromaculata were demonstrated in this study.

Results showed that sperm motility and sperm count were significantly and negatively correlated with exposure time and concentration. By contrast, abnormal sperm rate was positively correlated with both parameters.

Ultrastructural observation results revealed abnormal sperm morphologies, vacuoles in spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. These results indicated that MCLR could induce toxic effects on the reproductive system of frogs , significantly decrease testosterone content, and rapidly increase estradiol content.

Prolonged exposure and increased concentration enhanced the relative expression levels of P aromatase and steroidogenic factor 1; thus, endocrine function in frogs was disrupted. This study provided a scientific basis of the global decline in amphibian populations. Effects of mosquitofish Gambusia affinis cues on wood frog Lithobates sylvaticus tadpole activity.

Full Text Available We examined the changes in activity of wood frog Lithobates sylvaticus tadpoles exposed to combinations of visual, chemical, and mechanical cues of the invasive mosquitofish Gambusia affinis. We also examined whether the responses of the tadpoles to the predator cues were influenced by the short-term accumulation of chemical cues in the experimental container. In our experiment, the activity of wood frog L. Our experiment demonstrated that the repeated use of trial water can influence the activity level of tadpoles, regardless of the predator cue treatment used.

Tadpoles in the first trial tended to be less active than tadpoles in subsequent trials. This effect does not appear to be mediated by the accumulation of predator cues since there was no significant interaction term. Our results suggest that short-term accumulation of predator chemical cues do not affect the behavior of wood frog tadpoles: however, our results suggest that the repeated use of the same water in consecutive trials may affect tadpole behavior, perhaps through the accumulation of conspecific chemical cues.

In the late s, Rana muscosa mountain yellow-legged frog was common in the Tableland area of Sequoia National Park, California where it was possible to find hundreds of tadpoles and adults around many of the ponds and lakes. Surveys in demonstrated that R. At that same time, R. To evaluate the potential causes for the extirpation, we repatriated R.

We subsequently surveyed each release site and the surrounding area 2 - 3 times per week in , and intermittently in , to monitor the survival of all life history stages, and to detect dispersal of adults and subadults. We also monitored predation, water quality, weather, and water temperature. Our techniques for capturing, holding, transporting, and releasing R.

Adult frogs were anaesthetized, weighed, measured, tagged, and held in plastic boxes with wet paper towels. Tadpoles were collected and held in fiberglass screen cages set in the water at the edge of a pond. This resulted in relatively natural conditions with less crowding and good water circulation. Frogs , tadpoles, and eggs were placed in Ziploc bags for transport to the Tableland by helicopter. Short-term survival of tadpoles, subadults, and adults was high at all four release sites, tadpoles reached metamorphosis, and adult frogs were still present.

However, we detected no evidence of reproduction at three sites e. At the fourth site, there was limited reproduction, but it was. Efficacy of ivermectin as an anthelmintic in leopard frogs. Three clinical trials were conducted. In the first trial, 5 groups of 11 frogs were given ivermectin IM at dosages of 0, 0.

All frogs given ivermectin IM at dosages of 2. In trial 2, 44 frogs , allotted to 5 groups, were given ivermectin cutaneously at 0, 0. In trial 3, nematode infections were eliminated in all 10 frogs treated cutaneously with ivermectin at 2. Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity.

Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracell Full Text Available Frog is an amphibian which is widely spread around the world.

In Java Island alone, there live 42 species of frogs and toads. Frogs can be used as an environment indicator in that the presence of frog in a particular place indicates that the place stays natural and unpolluted. The 1st Campus of State University of Malang, which is located in the heart of Malang District, has been developing rapidly currently.

Thus, it requires the construction of new various facilities to support its huge activities. This study is aimed to identify the species of frog which survives at State University of Malang with, particularly the frog species found in Species identification was conducted by observing the morphological character. This study found that there were four species with three species remained survived in ; those were Duttaphrynus melanostictus, Polypedates leucomystax, and Kaloula baleta; and one new species called Rana chalconota.

This study also revealed that there were four species which were extinct; those were Fejervarya cancrivora, Fejervarya limnocharis, Ingerophrynus biporcatus, and Occidoziga lima. This situation shows the decreasing amount of species from 7 to 4 within the last 17 years. This result indicates that there is a serious environmental degradation which causes the losing of frog habitats. Further research is needed to study the ecological condition changing in order to save the frog species.

Multispecies benefits of wetland conservation for marsh birds, frogs , and species at risk. Wetlands conserved using water level manipulation, cattle exclusion, naturalization of uplands, and other techniques under the North American Waterfowl Management Plan "conservation project wetlands" are important for ducks, geese, and swans "waterfowl". However, the assumption that conservation actions for waterfowl also benefit other wildlife is rarely quantified.

We modeled detection and occupancy of species at sites within 42 conservation project wetlands compared to sites within 52 similar nearby unmanaged wetlands throughout southern Ontario, Canada, and small portions of the adjacent U. Notably, occupancy of priority conservation concern or at-risk Black Tern Chlidonias niger , Common Gallinule Gallinula galeata , Least Bittern Ixobrychus exilis , Sora Porzana carolina , and Western Chorus Frog Pseudacris triseriata was significantly higher at conservation project sites compared to unmanaged sites.

The results demonstrate the utility of citizen science to inform wetland conservation, and suggest that actions under the North American Waterfowl Management Plan are effective for conserving non-waterfowl species. Frog virus 3 was isolated from a strawberry poison frog Oophaga pumilio imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Adaptive plasticity of skeletal muscle energetics in hibernating frogs : mitochondrial proton leak during metabolic depression.

The common frog Rana temporaria spends the coldest months of each year overwintering in ice-covered ponds where temperatures can vary from 0. Over the course of a winter season, the animals enter progressively into a state of metabolic depression that relies almost exclusively on aerobic production of ATP. Little is known about the properties of mitochondria during prolonged periods of metabolic depression, so we have examined several aspects of mitochondrial metabolism in the skeletal muscle of frogs over periods of hibernation of up to 4 months.

Mitochondria isolated from the skeletal muscle of frogs hibernating in hypoxic water show a considerable reorganisation of function compared with those isolated from normoxic submerged animals at the same temperature 3 degrees C. Both the active state 3 and resting state 4 respiration rates of mitochondria decrease during hypoxic, but not normoxic, hibernation.

In addition, the affinity of mitochondria for oxygen increases during periods of acute hypoxic stress during normoxic hibernation as well as during long-term hibernation in hypoxic water. The decrease in mitochondrial state 4 respiration rates during hypoxic hibernation evidently occurs through a reduction in electron-transport chain activity, not through a lowered proton conductance of the mitochondrial inner membrane.

The reduced aerobic capacity of frog skeletal muscle during hypoxic hibernation is accompanied by lowered activities of key enzymes of mitochondrial metabolism caused by changes in the intrinsic. Complete genome sequence of frog virus 3, isolated from a strawberry poison frog Oophaga pumilio imported from nicaragua into the Netherlands. FROG [1] [2] is a generic framework dedicated to visualisation of events in high energy experiment.

It is suitable to any particular physics experiment or detector design. The code is light FROG does not require installation of third party libraries for the visualisation. This documents describes the features and principles of FROG version 1.

Metabolomic profiling of Green Frogs exposed to Mixed Pesticides. This dataset is associated with the following Plasticity of peripheral auditory frequency sensitivity in Emei music frog. In anurans reproductive behavior is strongly seasonal. During the spring, frogs emerge from hibernation and males vocalize for mating or advertising territories.

Female frogs have the ability to evaluate the quality of the males' resources on the basis of these vocalizations. Although studies revealed that central single torus semicircularis neurons in frogs exhibit season plasticity, the plasticity of peripheral auditory sensitivity in frog is unknown. In this study the seasonally plasticity of peripheral auditory sensitivity was test in the Emei music frog Babina daunchina, by comparing thresholds and latencies of auditory brainstem responses ABRs evoked by tone pips and clicks in the reproductive and non-reproductive seasons.

The results show that both ABR thresholds and latency differ significantly between the reproductive and non-reproductive seasons. The thresholds of tone pip evoked ABRs in the non-reproductive season increased significantly about 10 dB than those in the reproductive season for frequencies from 1 KHz to 6 KHz. ABR latencies to waveform valley values for tone pips for the same frequencies using appropriate threshold stimulus levels are longer than those in the reproductive season for frequencies from 1.

These results demonstrated that peripheral auditory frequency sensitivity exhibits seasonal plasticity changes which may be adaptive to seasonal reproductive behavior in frogs. Full Text Available In anurans reproductive behavior is strongly seasonal.

Is chytridiomycosis driving Darwin's frogs to extinction? Rhinoderma rufum has not been found in the wild since We investigated historical and current evidence of Batrachochytrium dendrobatidis Bd infection in Rhinoderma spp. Archived and live specimens of Rhinoderma spp. Six 0. Details of the WCS synthetic bitumen synergy were examined, as well as quality management issues.

It was suggested that further optimization of WCS facilities include reduced operating complexity; less tank proliferation; delivery quality consistency; and reliability. WCS refiner advantages were also evaluated. Shipping and ramping details were discussed, along with growth potential. It was noted that WCS satisfies all the criteria for a benchmark crude. It was concluded that the case for a large Canadian heavy oil stream includes reduced operating complexity; optimized logistics; delivery quality consistency; improved stream liquidity; and enhanced price discovery.

Heavy metals in Pantanoso and Miguelete small stream. The streams Miguelete and Pantanoso in the city of Montevideo present high levels of organic and inorganic contamination. The main causes of this deterioration are: old and inadequate reparation systems and the contamination is generated by the pokers and the industry.

The tanneries and laundries of wools are the highly pollutant industries. In the two streams a marked relationship between the levels of heavy metals and the distribution of the industries responsible for the contamination was observed. A study of the enrichment of Pb,Cu, Zn and Cr in the sediments exists.

Levels of Chromium in the Pantanoso Stream is very high due to the existence of three tanneries [es. The effect of bottom sediment supplement on heavy metals content in plants Zea mays and soil. Directory of Open Access Journals Sweden. Full Text Available Important aspect of bottom sediments is the problem of their management or disposal after their extraction from the bottom of rivers, dam reservoirs, ports, channels or ponds. The research aimed at an assessment of potential environmental management of bottom sediment used as an admixture to light soil basing on its effect on contents of heavy metals in plants and soil.

The research was conducted on light soil with granulometric structure of weakly loamy sand. The sediment applied in the presented research revealed high share of silt and clay fractions, alkaline pH and low contents of heavy metals, therefore it may be used as an admixture to the above mentioned soils to improve their productivity. The applied bottom sediment to the soil affected a decreased in Zn, Cd and Pb content in maize in comparison with the treatment without the deposit whereas increased content of Cu, Cr and Ni.

No exceeded permissible content of heavy metals concerning plant assessment in view of their forage usability were registered in maize biomass. Full Text Available Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries.

However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. These were analyzed using the absorption spectrophotometer method. The geoaccumulation Igeo and pollution load indices PLI were used to assess the level of heavy metal contamination of surrounding soils.

It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites. Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. To determine heavy metal Hg, Pb, Cd, Cr, and Ag in levels in incinerator bottom ash and soils m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, m, and 1, m from incinerator.

The geoaccumulation I geo and pollution load indices PLI were used to assess the level of heavy metal contamination of surrounding soils. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. High-frequency internal waves and thick bottom mixed layers observed by gliders in the Gulf Stream.

Autonomous underwater gliders are conducting high-resolution surveys within the Gulf Stream along the U. East Coast. Glider surveys reveal two mechanisms by which energy is extracted from the Gulf Stream as it flows over the Blake Plateau, a portion of the outer continental shelf between Florida and North Carolina where bottom depths are less than m.

Internal waves with vertical velocities exceeding 0. These waves are likely internal lee waves generated by the subinertial Gulf Stream flow over the irregular bathymetry of the outer continental shelf. Bottom mixed layers with O m thickness are also frequently encountered; these thick bottom mixed layers likely form in the lee of topography due to enhanced turbulence generated by O 1 m s-1 near- bottom flows. These results are part of a screening test that investigates three grout formulations proposed for wide-range treatment of different waste stream compositions expected for the Hanford Effluent Management Facility EMF evaporator bottom waste.

This work supports the technical development need for alternative disposition paths for the EMF evaporator bottom wastes and future direct feed low-activity waste DFLAW operations at the Hanford Site. High-priority activities included simulant production, grout formulation, and cementitious waste form qualification testing.

The work contained within this report relates to waste form development and testing, and does not directly support the Integrated Disposal Facility IDF performance assessment PA. However, this work contains valuable information for use in PA maintenance past FY and future waste form development efforts. The provided results and data should be used by 1 cementitious waste form scientists to further the understanding of cementitious leach behavior of contaminants of concern COCs , 2 decision makers interested in off-site waste form disposal, and 3 the U.

The results reported help fill existing data gaps, support final selection of a cementitious waste form for the EMF evaporator bottom waste, and improve the technical defensibility of long-term waste form risk estimates. Comparison of leaching characteristics of heavy metals from bottom and fly ashes in Korea and Japan.

The objective of this research was to compare the leaching characteristics of heavy metals such as cadmium, chromium, copper, nickel, lead, etc. The rate of leaching of heavy metal was measured by KSLT and JTL, and the amount of heavy metals leached was compared with the metal content in each waste component. Finally, bio-availability testing was performed to assess the risks associated with heavy metals leached from bottom ash and fly ash.

From the results, the value of neutralization ability in Japanese fly ash was four times higher than that in Korean fly ash. The reason was the difference in the content of Ca OH 2 in fly ash. The amount of lead leached exceeded the regulatory level in both Japanese and Korean fly ash. The rate of leaching was relatively low in ash with a pH in the range of The leaching concentration of lead exceeded the Japanese risk level in all fly ashes from the two countries, but the leaching concentration of cadmium exceeded the regulatory level in Korean fly ash only.

Dubai creek can be considered as the focal point of Dubai. It has great importance for trading and aesthetic values. Total and leachable heavy metals Cd, Co, Ni, Pb and Zn , organic carbon and total carbonate were studied in the bottom sediments of the creek.

Pollution Load Index, statistical analysis, were used in order to quantify the pollution load as well as to discriminate the data into significant groups. Normalization of the data using organic carbon and total carbonate was done in or Full Text Available Coal ash is the residue that is produced during coal combustion for instance fly ash, bottom ash or boiler slag which was primarily produced from the combustion of coal.

With growth in coal burning power station, huge amount of coal bottom ash CBA considered as hazardous material which are normally disposed in an on-site disposal system without any commercialization purpose. Previous researchers have studied the extraction of silica from agricultural wastes such as palm ash and rice husk ash RHA and CBA by using leaching treatment method.

In this study, the weaker acid, citric acid solution was used to replace the strong acid in leaching treatment process. Technical and economic study of Stirling and Rankine cycle bottoming systems for heavy truck diesel engines. Bottoming cycle concepts for heavy duty transport engine applications were studied. In particular, the following tasks were performed: 1 conceptual design and cost data development for Stirling systems; 2 life-cycle cost evaluation of three bottoming systems - organic Rankine, steam Rankine, and Stirling cycles; and 3 assessment of future directions in waste heat utilization research.

The study shows that none of the three bottoming systems studied are even marginally attractive. It utilizes one of the diesel cylinders as an expander and capitalizes on the in-cylinder heat energy. The concept eliminates the need for the power transmission device and a sophisticated control system, and reduces the size of the exhaust evaporator. Results of an economic evaluation indicate that the system has the potential to become an attractive package for end users.

Content and the forms of heavy metals in bottom sediments in the zone of industrial pollution sources ,. Full Text Available Regularities in the distribution of heavy metals in sediments in the zone of influence of the steel industry in Mariupol are installed. Ecological and geochemical assessment of sediment contamination by heavy metals is performed. The main sources of pollution of bottom sediments are air borne emissions from industrial plants, hydrogenous pollution in industrial sewage entering the water, sewage sludge, ash dumps, slag, ore, sludge, oil spills and salt solutions.

Pollution hydrogenous sediments may be significant, contaminated sediments are a source of long-term contamination of water, even after cessation of discharges into rivers untreated wastewater. The environmental condition of bottom sediments in gross content of heavy metals is little information because they do not reflect the transformation and further migration to adjacent environment.

The study forms of giving objective information for ecological and geochemical evaluation. The study forms of heavy metals in the sediments carried by successive extracts. Concentrations of heavy metals in the extracts determined by atomic absorption spectrometer analysis CAS It was established that a number of elements typical of exceeding their content in bottom sediments of the background values, due likely to their technogenic origin.

Man-made pollution of bottom sediments. Mariupol has disrupted the natural form of the ratio of heavy metals. In the studied sediments form ion exchange increased content of heavy metals, which contributes to their migration in the aquatic environment.

Determination of heavy metals in the stream of Sunter river. An environmental pollution study was made on four locations of waste water along the stream of Sunter river during the period of June to March Trace heavy metals could be separated by chelation with sodium diethyl dithiocarbamate NaDDC extracted into methyl isobuthyl ketone MIBK and determined by atomic absorption spectrophotometer AAS except mercury which was determined flamelessly.

Physical parameters including pH, temperature, turbidity and dissolved oxygen D. O were also determined by water checker. The results obtained were as follows: Hg 1. The physical parameters were: pH 6. Data obtained showed that especially mercury and lead were high in concentration, i. Hg: Full Text Available A study on heavy metals assessment in the water of Sahastradhara hill- stream was conducted with different five sites at significant differences.

The present paper deals with the water quality status of Sahastradhara stream by the assessment of heavy metals. Heavy Metals were found in fluctuated trend from first upstream to last downstream. The values of almost all Heavy Metals were found in increasing manner especially after the fourth sampling site.

After the third sampling station, a solid waste dumping site was found. So, there may be a relation between heavy metals in stream water and solid waste dumping site. Concentrations of all Heavy Metals at fourth and fifth sampling site were found very high. Assessment of stream bottom sediment quality in the vicinity of the Caldas uranium mine. Oliveira, Priscila E. Laboratorio de Pocos de Caldas. In order to perform the research, twelve sampling stations were established in the watersheds around Caldas UMMF: the Soberbo creek, the Consulta brook, and the Taquari river.

One of the stations was located inside the Bacia Nestor Figueiredo, a retention pond that receives effluents from WRP4, and another in a settling tank D2 for radium, which receives the effluents from TD. Detailed investigation in sub-superficial layers is recommended at these locations to evaluate the need of implementing mitigation actions such as lining and constructing hydraulic barriers downstream the ponds.

Origin of a bottom-heavy stellar initial mass function in elliptical galaxies. We investigate the origin of a bottom-heavy stellar initial mass function IMF recently observed in elliptical galaxies by using chemical evolution models with a non-universal IMF. Full Text Available In the Pikes Peak oil field near Lloydminster, Canada, a significant amount of heavy oil reserves is located in reservoirs with a bottom water zone.

The properties of the bottom water zone and the operation parameters significantly affect oil production performance via the steam-assisted gravity drainage SAGD process. Thus, in order to develop this type of heavy oil resource, a full understanding of the effects of these properties is necessary. In this study, the numerical simulation approach was applied to study the effects of properties in the bottom water zone in the SAGD process, such as the initial gas oil ratio, the thickness of the reservoir, and oil saturation of the bottom water zone.

In addition, some operation parameters were studied including the injection pressure, the SAGD well pair location, and five different well patterns: 1 two corner wells, 2 triple wells, 3 downhole water sink well, 4 vertical injectors with a horizontal producer, and 5 fishbone well. The numerical simulation results suggest that the properties of the bottom water zone affect production performance extremely.

First, both positive and negative effects were observed when solution gas exists in the heavy oil. Second, a logarithmical relationship was investigated between the bottom water production ratio and the thickness of the bottom water zone.

Furthermore, the operation parameters affected the heavy oil production performance. Comparison of the well patterns showed that the two corner wells and the triple wells patterns obtained the highest oil recovery factors of This indicates that the optimized SAGD process. The mean Impact of heavy metals on macro-invertebrate fauna of the thaddo stream. Impact of some heavy metals like zinc, lead, copper, chromium and cadmium were studied at four spots on the macro-invertebrate fauna of the Thaddo stream , a tributary of Malir River.

This was in correlation with an earlier study on the physico-chemical aspects of water which showed a severe pollution in this stream. Present data for the qualitative and quantitative analyses of macro-invertebrates and the ranges of heavy metals Zn 0. Macro-invertebrate fauna comprises only of aquatic insects which include larvae of Chironomus spp. Quantitatively Notonectus sp.

The maximum concentrations of all heavy metals were recorded at spot 3. A general trend of increase was observed from up stream to down stream regions particularly in the level of zinc. However, a reverse trend was observed in the abundance of macro-invertebrates with a great reduction at spot 4.

The statistical analysis of the data generally indicates a negative correlation between the values of the studied heavy metals and the abundance of macro-invertebrates throughout this study. Full Text Available Polyphonic music listening well exemplifies processes typically involved in daily auditory scene analysis situations, relying on an interactive interplay between bottom -up and top-down processes.

Most studies investigating scene analysis have used elementary auditory scenes, however real-world scene analysis is far more complex. In particular, music, contrary to most other natural auditory scenes, can be perceived by either integrating or, under attentive control, segregating sound streams , often carried by different instruments. One of the prominent bottom -up cues contributing to multi-instrument music perception is their timbre difference.

In this work, we introduce and validate a novel paradigm designed to investigate, within naturalistic musical auditory scenes, attentive modulation as well as its interaction with bottom -up processes. Two psychophysical experiments are described, employing custom-composed two-voice polyphonic music pieces within a framework implementing a behavioral performance metric to validate listener instructions requiring either integration or segregation of scene elements.

In Experiment 1, the listeners' locus of attention was switched between individual instruments or the aggregate i. Subjects responded post-stimulus whether triplets were present in the to-be-attended instrument s. Experiment 2 introduced the bottom -up manipulation by adding a three-level morphing of instrument timbre distance to the attentional framework.

The task was designed to be used within neuroimaging paradigms; Experiment 2 was additionally validated behaviorally in the functional Magnetic Resonance Imaging fMRI environment. Polyphonic music listening well exemplifies processes typically involved in daily auditory scene analysis situations, relying on an interactive interplay between bottom -up and top-down processes. Nineteen listeners also. Assessment of heavy metals pollution in bottom sediments of the Arabian Gulf after the Gulf War oil spill The major objective of this study was to carry out a sequential geochemical extraction scheme for the partitioning of Fe, Mn, Co, Cu, Zn, Ni, Cr and Pb in the bottom sediments of the Arabian Gulf to detect any potential pollution impact on the gulf sediments following the gulf war oil spill, and to differentiate between anthropogenic inputs and natural background of heavy metals.

Delivery of suspended sediment and associated phosphorus and heavy metals to small rural Danish streams. The aim of this study is to examine delivery pathways for suspended sediment, and particulate phosphorus P and heavy metals from open rural areas to small Danish streams.

A further aim is to quantify the contribution from different path-ways and source areas. Such studies are useful as a basis The occurrence of heavy metals and metal-resistant bacteria in water and bottom sediments of the Straszyn reservoir Poland. From the microbiological side a significant part of heterotrophic bacteria isolated from the bottom sediment and surface water raw and treated water showed a resistance to 0.

The results indicate also that water treatment processes may contribute to the selection of resistant strains. The distribution of heavy metals content in the bottom deposits of the trans-border Uzh river system. An excess in maximum permissible concentration among such elements as Zn, V, As, and Cu was detected in surface waters. We may connect the elevated level of Cu and Zn with natural metals appearing in ground water run-off, ablation from iron ore, the reaction of interstitial water, anthropogenic sewage disposals from communal households and manufacturing plants, agricultural run-offs, and hydrochemical pH of water medium, methylation of non-organic metal compounds, metals release from the organic compounds composition, ingress from bottom deposits factors.

The high concentrations of vanadium in water as well as in bottom deposits are most probably induced by the leaching of elements from the regional volcanic rocks. The plumbum content did not exceed the higher-than-normal rates; however, significant element accumulation was detected in bottom deposits outside the city of Uzhgorod which may be the result of ecotoxicant ingress along with land runoff from the riverside highways laid parallel to the water course.

In comparison with background measures, the highest chromium and nickel concentrations were detected near the streamlet Domoradzh and, therefore, it is assumed that the industrial wastewaters serve here as a source of heavy metals. The reservoir in the lowland is above all enriched by arsenic. Areas under agricultural use are significantly concentrated in lowlands.

Runoffs from these areas are the main source of the ore supply. However, the impact of municipal domestic waste water which contains arsenic-containing detergents should not be excluded. Moreover, we found a relationship between the relief heterogeneity of the study area and distribution of heavy metals in the hydro-ecosystem. The accomplished comparative analysis of the territories under study indicates the significant.

Heavy metal contamination of stream water and sediment in the Taejon area. Associated with the rapid pace of overpopulation and industrialization is the increase of municipal and industrial wastewater and heavy metal contamination from these point sources have received much attention in the Taejon area.

To reduce the environmental problems, 21 stream sediments from Gap-chun, Yudeung-chun, Yusung-chun and Keum river have been analyzed for Cd, Cu, Pb and Zn. When the geochemical map drawn from the Kriging technique of these data are compared with the industrialization and urbanization index map, high concentrations of heavy metals are found in stream sediments in industrialized areas resulting from the accumulation of heavy metals from the polluting factories.

A and may be the potential sources of pollution in Keum river with possible implications to human health. For the speciation of Cu, Pb and Zn, the high proportions of exchangeable phase of Cu and Zn in stream sediments indicate that the metals originate not from parent materials but from wastewater and exist as the adsorbed phase on the surface of sediments.

Enrichment and geochemical mobility of heavy metals in bottom sediment of the Hoedong reservoir, Korea and their source apportionment. Physicochemical characteristics of bottom sediment in the Hoedong reservoir were studied to evaluate the effectiveness of the reservoir as traps for trace metals. Roadside soil, stream sediment and background soil were also studied for comparison.

Sequential extractions were carried out, and lead isotopic compositions of each extraction were determined to apportion Pb sources. Besides, particle size distribution of roadside soil, and metal concentrations and Pb isotopes of each size group were determined to characterize metal contamination. In result, Zn and Cu were enriched in sediment through roadside soil.

The data on metal partitioning implied that Zn posed potential hazards for water quality. Metal concentrations and Pb isotopic compositions indicated that sediments were a mixture of background and roadside soil. The residual fraction of sediments appeared to be as contaminated as the non-residual fractions.

All rights reserved. High purity heavy water production: need for total organic carbon determination in process water streams. In recent times, demand for high purity heavy water Its application started in nuclear industry with the design of CANDU reactor, which uses natural uranium as fuel. In this reactor the purest grade of heavy water is used as the moderator and the primary coolant.

Diverse industrial applications like fibre optics, medicine, semiconductors etc. In all these applications there is a stringent requirement that the total organic carbon content TOC of high purity heavy water should be very low.

This is because the presence of TOC can lead to adverse interactions in different applications. To minimize the TOC content in the final product there is a need to monitor and control the TOC content at each and every stage of heavy water production. Hence a simple, rapid and accurate method was developed for the determination of TOC content in process water samples. The paper summarizes the results obtained for the TOC content in the water samples collected from process streams of heavy water production plant.

Urban stormwater runoff is a major cause of water quality impairment along ocean shorelines and in rivers, lakes and estuaries across the United States. In addition to pathogens, nutrients, and organic contaminants, a variety of heavy metals are commonly found at elevated concentrations in urban runoff. Although such metals occur in both dissolved and particulate-bound phases, conventional stormwater controls are typically designed to remove suspended solids, while dissolved phase contaminants remain largely untreated.

To address this gap in available stormwater controls, a novel technology, termed Biohydrochemical Enhancements for Streamwater Treatment BEST , has been developed based on inspiration from the natural hyporheic zone HZ. BEST utilizes a series of alternating streambed permeabilities to drive efficient surface water-HZ exchange. Previous research at the Colorado School of Mines has shown that a meter flume modified with BEST exhibits greater hyporheic exchange than an all-sand control flume, though both flumes provided greater contaminant attenuation than a selection of actual urban streams.

This study again utilized the meter flumes at Colorado School of Mines to evaluate two configurations of BEST for removal of heavy metals commonly found in stormwater runoff, including cadmium, copper, nickel, lead and zinc. Both configurations were compared to an all-sand control. To evaluate metals removal, a suite of aqueous metals solution was spiked into each flume, and aqueous concentrations of the five metals of interest were monitored in both the surface and pore water over 24 hours.

Differences in. Heavy metals are naturally presented in different chemical bonds within sediment. Different factors affect metals bonding in sediment. One of those factors is changing in Redox potential. In the present study the effect of redox potential on fractionation and bonding of metals within Anzali international wetland bottom sediment is investigated.

Sediment samples of Anzali wetland were aerated for one month and redox potential and p H was measured at 0, 1, 7, 21, and 28th days. Subsamples of sediments at mentioned days of experiments were taken and analyzed for Cu, Zn, Ni, and Cr for deferent chemical bonds using sequential extraction analysis.

Nickel and Cr were mostly associated in hard residual bonds. Effects of anthropogenic heavy metal contamination on litter decomposition in streams — A meta-analysis. Many streams worldwide are affected by heavy metal contamination, mostly due to past and present mining activities. Here we present a meta-analysis of 38 studies reporting cases published between and that reported the effects of heavy metal contamination on the decomposition of terrestrial litter in running waters.

Overall, heavy metal contamination significantly inhibited litter decomposition. The effect was stronger for laboratory than for field studies, likely due to better control of confounding variables in the former, antagonistic interactions between metals and other environmental variables in the latter or differences in metal identity and concentration between studies. For field studies, coal and metal mine drainage strongly inhibited litter decomposition, while drainage from motorways had no significant effects.

The effect of coal mine drainage did not depend on drainage pH. Coal mine drainage negatively affected leaf litter decomposition independently of leaf litter identity; no significant effect was found for wood decomposition, but sample size was low. Considering metal mine drainage, arsenic mines had a stronger negative effect on leaf litter decomposition than gold or pyrite mines.

Metal mine drainage significantly inhibited leaf litter decomposition driven by both microbes and invertebrates, independently of leaf litter identity; no significant effect was found for microbially driven decomposition, but sample size was low. Overall, mine drainage negatively affects leaf litter decomposition, likely through negative effects on invertebrates.

Lake Umbozero is the second largest lake in the Murmansk Region and subjected to contamination by air Unlike its neighboring, more industry-prone Lake Imandra, Lake Umbozero is relatively unexplored with respect to its state of pollution. In our study, metal distribution in sediments was found to vary with respect An exception was Pb the concentration of which was at the same level as in Lake Imandra, probably due to long-distance transport.

Sediment layers were subjected to four-step sequential extraction procedure to reveal the metal Experimental study of properties of heavy concrete with bottom ash from power stations. Full Text Available This article deals with the influence of cement quantity, plasticizing additives and compaction time on the strength and water consumption of concrete during its manufacturing using bottom ash from a thermal power station.

The study was carried out using three factorial experiments. Variables varied on three levels. The obtained pattern functions characterize a relationship between strength, water consumption and variable factors. These factors include cement quantity, plasticize additives and compaction time.

Compilation of Pareto effect charts allowed estimation of the significance of function indexes. Analysis of surface pattern function has revealed the optimal correlation between additive quantity and compaction time, cement quantity and additive quantity, cement quantity and compaction time.

Compression strength of concrete was taken as the pattern in the pattern function. When analyzing the pattern function with water consumption as a pattern, optimal correlations between additive quantity and compaction time, cement quantity and additive quantity, cement quantity and compaction time were revealed.

Correlations of components which have an impact on water consumption have been determined. The conclusions contain the quantitative findings of the study. Full Text Available The development of industry, agriculture, and transport contributes to an increased environmental pollution by heavy metals.

The aim of the study was preliminary assessment of the contents of selected metals lead, cobalt, copper, chromium, cadmium and nickel in the sediments of Bug river. The study comprised part of the river flowing through Poland. It was found that the Bug river sediments are not contaminated in respect to the content of tested metals. Statistical analysis showed that copper and chromium occur in Bug river sediments in forms bindings with organic matter in majority of cases.

The granulometric analysis of sediments from Bug river revealed the largest percentage of two fractions: 1. These are the dominant fractions with the accumulation of metals in river sediments, which has been confirmed by statistical analysis. Land-based sources of marine pollution: Pesticides, PAHs and phthalates in coastal stream water, and heavy metals in coastal stream sediments in American Samoa. The island nations and territories of the South Pacific are facing a number of pressing environmental concerns, including solid waste management and coastal pollution.

Here we provide baseline information on the presence and concentration of heavy metals and selected organic contaminants pesticides, PAHs, phthalates in 7 coastal streams and in surface waters adjacent to the Futiga landfill in American Samoa. All sampled stream sediments contained high concentrations of lead, and some of mercury.

Several coastal stream waters showed relatively high concentrations of diethyl phthalate and of organophosphate pesticides, above chronic toxicity values for fish and other aquatic organisms. Parathion, which has been banned by the US Environmental Protection Agency since , was detected in several stream sites. Increased monitoring and initiatives to limit non-point source land-based pollution will greatly improve the state of freshwater and coastal resources, as well as reduce risks to human health in American Samoa.

Leaves and roots of Typha latifolia L. Full Text Available The paper concerns the bioaccumulation of zinc, nickel, iron and manganese in leaves and roots of selected macrophytes from the Krzynia Reservoir northern Poland. The research was conducted within the area of 10 stations situated in the littoral zone of the reservoir.

Samples of surface waters, bottom sediments and plants were taken in summer. Heavy metal content was determined by the atomic absorption spectrometry method ASA. The concentration of heavy metals in the waters of Krzynia Reservoir was low and noinfluence of anthropogenic factors was found.

Concentration of heavy metals in the examined bottom sediments was low and remained within the limits of the geochemical background for Zn and Fe. In the case of Ni and Mn it sporadically exceeded the level of the geochemical background. The tested plants mainly accumulated heavy metals in roots, with the exception of nickel which appeared in larger quantities in leaves.

Statistically significant differences were found in the content of Mn in leaves and Zn and Fe in the roots of Typha latifolia L. By accumulating substantial quantities of heavy metals in their organs, macrophytes constitute an effective protective barrier for the waters and bottom sediments. Soil contamination with heavy metals has caused serious environmental problems and increased the risks to humans and biota.

Herein, we developed an effective bottom up metals removal system based on the synergy between the activation of immobilization metal-resistant bacteria and the extraction of bioaccumulator material Stropharia rugosoannulata. Optimized by response surface methodology, the biochar and bacterial suspension were mixed at a ratio of w:v for 12 h when 2. Results demonstrated that the system significantly increased the proportion of acid soluble Cd and Cu and improved the soil microecology microbial counts, soil respiration, and enzyme activities.

The maximum extractions of Cd and Cu were 8. Moreover, details of the possible mechanistic insight into the metal removal are discussed, which indicate positive correlation with the acetic acid extractable metals and soil microecology.

Meanwhile, the "dilution effect" in S. Furthermore, the metal-resistant bacteria in this system were successfully colonized, and the soil bacteria community were evaluated to understand the microbial diversity in metal-contaminated soil after remediation.

Geochemical distribution and mobility of heavy metals in sediments of urban streams affected by combined sewer overflows. Fungi in a heavy metal precipitating stream in the Mansfeld mining district, Germany. Fungal growth on alder leaves was studied in two heavy metal polluted streams in central Germany.

The aim of the study was to examine previously observed differences in leaf decomposition rates, heavy metal precipitation and fungal involvement in these processes at the microscopic level. Ergosterol analyses indicated that neither habitat was optimal for fungi, but leaves exposed at the less polluted site H8 decomposed rapidly and were colonized externally and internally by fungi and other microorganisms.

Leaves exposed at the more polluted site H4 decomposed very slowly and fungal colonization was restricted to external surfaces. An amorphous organic layer, deposited within 24 h of exposure, quickly became covered with a pale blue-green crystalline deposit zincowoodwardite with significant amounts of Al, S, Cu and Zn, determined by energy dispersive X-ray spectroscopy EDS.

Scanning electron microscopy SEM analysis of the precipitate revealed a branching arrangement of the precipitated particles caused by the presence of fungal hyphae growing on the surface. Hyphae that were not disturbed by handling were usually completely encased in the precipitate, but hyphae did not contain EDS-detectable amounts of precipitate metals. The formation of metal precipitates on various artificial substrates at site H4 was much reduced compared to leaves, which we attribute to the absence of fungal colonization on the artificial substrates.

We could not determine whether fungi accelerate the precipitation of heavy metals at site H4, but mycelial growth on leaves continues to create new surfaces and therefore thicker layers of precipitate on leaves compared to artificial substrates.

Ehrman, James M. Desulfurization of the hot reformate gas produced by catalytic partial oxidation or autothermal reforming of heavy fuels, such as JP-8 and jet fuels, is required prior to using the gas in a solid oxide fuel cell SOFC. Development of suitable sorbent materials involves the identification of sorbents with favorable sulfidation equilibria, good kinetics, and high structural stability and regenerability at the SOFC operating temperatures to C.

Over the last two decades, a major barrier to the development of regenerable desulfurization sorbents has been the gradual loss of sorbent performance in cyclic sulfidation and regeneration at such high temperatures. Mixed oxide compositions based on ceria were examined in this work as regenerable sorbents in simulated reformate gas mixtures and temperatures greater than C. Regeneration was carried out with dilute oxygen streams.

We have shown that under oxidative regeneration conditions, high regeneration space velocities greater than 80, h sup -1 can be used to suppress sulfate formation and shorten the total time required for sorbent regeneration. A major finding of this work is that the surface of ceria and lanthanan sorbents can be sulfided and regenerated completely, independent of the underlying bulk sorbent.

This is due to reversible adsorption of H2S on the surface of these sorbents even at temperatures as high as C. La-rich cerium oxide formulations are excellent for application to regenerative H2S removal from reformate gas streams at to C. Occurrence and partitioning of antibiotic compounds found in the water column and bottom sediments from a stream receiving two wastewater treatment plant effluents in Northern New Jersey, Gibs, Jacob, E-mail: jgibs usgs.

An urban watershed in northern New Jersey was studied to determine the presence of four classes of antibiotic compounds macrolides, fluoroquinolones, sulfonamides, and tetracyclines and six degradates in the water column and bottom sediments upstream and downstream from the discharges of two wastewater treatment plants WWTPs and a drinking-water intake DWI.

Many antibiotic compounds in the four classes not removed by conventional WWTPs enter receiving waters and partition to stream sediments. Samples were collected at nine sampling locations on 2 days in September Eight antibiotic compounds azithromycin maximum concentration 0.

The concentrations of six of the eight detected compounds and the detected degradate compound decreased with increasing distance downstream from the WWTP discharges. Azithromycin, ciprofloxacin, ofloxacin, and trimethoprim were detected in stream-bottom sediments. The concentrations of three of the four compounds detected in sediments were highest at a sampling site located downstream from the WWTP discharges. Trimethoprim was detected in the sediments from a background site.

Pseudo-partition coefficients normalized for streambed sediment organic carbon concentration were calculated for azithromycin. Gibs, Jacob; Heckathorn, Heather A. Pseudo-partition coefficients normalized for streambed sediment organic carbon concentration were calculated for azithromycin, ciprofloxacin. Previous investigation shave shown increased concentrations of lead and some other metals.

When the mine and processing plants ceased to operate, the direct transfer of heavy metals into the environment has strongly decreased. However, the deposits of poor ore and wastes from ore processing have remained as an indirect source of heavy metal pollution. Concentrations of cobalt, chrome, copper and nickel are increased in the area around Ravne as a result of the ironworks industry.

A specific case is Helenski potok,in which the concentrations of heavy metals strongly surpass the concentrations measured at all other locations. Two incinerators in Taiwan have recently attempted to reuse the fly and bottom ash that they produce, but the mutagenicity of these types of ash has not yet been assessed.

Therefore, we evaluated the mutagenicity of the ash with the Ames mutagenicity assay using the TA98, TA, and TA bacterial strains. We obtained three leachates from three leachants of varying pH values using the toxicity characteristic leaching procedure test recommended by the Taiwan Environmental Protection Agency Taiwan EPA. We then performed the Ames assay on the harvested leachates. To evaluate the possible relationship between the presence of heavy metals and mutagenicity, the concentrations of five heavy metals Cd, Cr, Cu, Pb, and Zn in the leachates were also determined.

The concentrations of Cd and Cr in the most acidic leachate from the precipitator fly ash and the Cd concentration in the most acidic leachate from the boiler fly ash exceeded the recommended limits. Notably, none of the nine leachates extracted from the boiler, precipitator, or bottom ashes displayed mutagenic activity. This data partially affirms the safety of the fly and bottom ash produced by certain incinerators.

Therefore, the biotoxicity of leachates from recycled ash should be routinely monitored before reusing the ash. Long-term variations in the distribution of radioactive Cs in plant, soil, stream bottom sand in a small forest in Fukushima prefecture.

The result of a car-borne survey from Fukushima city to Minamitsushima showed that the air dose rate declined faster than the physical attenuation due to decontamination, outside of forests. In a cedar forest, however, the radio-Cs concentrations in fresh needles and litter declined from to , probably because of washing and leaching by throughfall, and radio-Cs was accumulated in surface soil. In broadleaf forest, the buffer depth of radio-Cs in soil 1.

However, the buffer depth in the cedar forest overtook that in the broadleaf forest in December, 1. The radio-Cs values in the stream bottom sand were concentrated in smaller sand over 2 mm, 3. It is concerned that a part of them causes the outflow of radio-Cs as suspended sand. The relative radio-Cs concentration ratio between smaller bottom sand and surface soil, which indicates the outflow of radio-Cs from forest via stream declined 0.

However, we found that floating male flowers of cedar containing high radio-Cs Occurence of antibiotic compounds found in the water column and bottom sediments from a stream receiving two waste water treatment plant effluents in northern New Jersey, Pseudo-partition coefficients normalized for streambed sediment organic carbon concentration were calculated for azithromycin, ciprofloxacin, and. Full Text Available The concentration of heavy metals HM in the 4km urban drainage stream in Uyo was studied using grab and composite sampling of water from six stations on the stream , and analyzed by a multipurpose atomic absorption spectrophotometer.

The data were statistically analyzed using SPSS version 17 software arid correlated between stations and among samples. HM contamination was evaluated with the coefficient and rate of dispersion between stations and the Normalized Scatter Coefficient NSC. The seasonal distribution of metal pollution varied individually amongst metals at stations.

The Fe and Pb concentrations exceeded the safe drinking water standard, rendering the water quality not acceptable for drinking; however, the quality was within the safe limit for crop production along the river bank. The relative. However, in the dry season, Fe and Pb depleted at downstream at rates far higher than Zn as Cu was increasing.

Fe and Pb could be good pollution monitor for total maximum daily load TMDL pollution monitoring programme. The model is inspired by ideas of active and collaborative learning and builds on feedback strategies well-known from Just-in-Time Teaching, Flipped Classroom, and Peer The aim of the model is to provide both a concrete and comprehensible design toolkit for adopting and implementing educational technologies in higher science teaching practice and at the same time comply with diverse ambitions.

So far both teachers and educational developers have positively received the model and the initial design experiences show promise Some physiochemical and heavy metal concentration in surface water stream of Tutuka in the Kenyasi mining catchment area. The objectives of the study were to find out the contamination levels of pH, BOD5, Lead, Chromium, and Arsenic in the Akantansu stream of Tutuka to promote public health safety of people patronizing the stream for bathing and cooking.

Determination of pH was achieved using Etech instrument PC series where as BOD5 level was assessed by means of empirical standard laboratory test which determined the relative oxygen requirements of waste water, effluents and polluted water using the standard procedure as per America Public Health Association An AAS atomic absorption spectrometer was used for the analyses of heavy metals lead, chromium and arsenic.

The Research revealed that, the geometric mean levels of 0. However, due to slightly higher concentration of chromium 0. Removal of heavy -metal ions from dilute waste streams using membrane-based hybrid systems. At Bend research, the authors have developed hybrid systems that couple a process that removes solvent water and a process that removes solute metal ions such that toxic heavy -metal ions can be efficiently and selectively removed to very low levels while simultaneously concentrating the heavy -metal ions in relatively pure form.

Although this technology is broadly applicable, the authors are focusing on the development of a system to treat groundwater that is contaminated with heavy -metal ions. The process utilizes coupled transport and reverse osmosis to reduce chromium and uranium concentration down to parts-per-billion levels. Heavy metal contamination in an urban stream fed by contaminated air-conditioning and stormwater discharges. Urban waterways are impacted by diffuse stormwater runoff, yet other discharges can unintentionally contaminate them.

The Okeover stream in Christchurch, New Zealand, receives air-conditioning discharge, while its ephemeral reach relies on untreated stormwater flow. Despite rehabilitation efforts, the ecosystem is still highly disturbed. It was assumed that stormwater was the sole contamination source to the stream although water quality data were sparse. We therefore investigated its water and sediment quality and compared the data with appropriate ecotoxicological thresholds from all water sources.

Concentrations of metals Zn, Cu and Pb in stream baseflow, stormwater runoff, air-conditioning discharge and stream -bed sediments were quantified along with flow regimes to ascertain annual contaminant loads. There was an fold greater annual Cu load to the stream from air-conditioning discharge compared to stormwater runoff. Most Zn and Cu were dissolved species possibly enhancing metal bioavailability.

Elevated metal concentrations were also found throughout the stream sediments. Environmental investigations revealed unsuspected contamination from air-conditioning discharge that contributed greater Cu annual loads to an urban stream compared to stormwater inputs. This discovery helped reassess treatment strategies for regaining ecological integrity in the ecosystem.

The estimation of heavy metal concentration in FBR reprocessing solvent streams by density measurement. The application of density measurement to heavy metal monitoring in the solvent phase is described, including practical experience gained during three fast reactor fuel reprocessing campaigns. An experimental algorithm relating heavy metal concentration and sample density was generated from laboratory-measured density data, for uranyl nitrate dissolved in nitric acid loaded tri-butyl phosphate in odourless kerosene.

An Anton Paar calculating digital densimeter with remote cell operation was used for all density measurements, but the algorithm will give similar accuracy with any density measuring device capable of a precision of better than 0. For plant control purposes, the algorithm was simplified using a density referencing system, whereby the density of solvent not yet loaded with heavy metal is subtracted from the sample density.

This simplified algorithm compares very favourably with empirical algorithms, derived from numerical analysis of density data and chemically measured uranium and plutonium data obtained during fuel reprocessing campaigns, particularly when differences in the acidity of the solvent are considered before and after loading with heavy metal. This simplified algorithm had been successfully used for plant control of heavy metal loaded solvent during four fast reactor fuel reprocessing campaigns.

Search for heavy bottom -like quarks in 4. The b' quarks are assumed to decay exclusively to tW. Using a data sample corresponding to an integrated luminosity of 4. Method for enriching and separating heavy hydrogen isotopes from substance streams containing such isotopes by means of isotope exchange. The reaction product containing the value or value salt is separated from the solution.

The regenerated value is returned for reuse. The decay b' to tW is considered in this search. Full Text Available Bottom sediments samples for chemical analysis were derived from Gowienica river and its tributaries. Samples were taken at and years from established sampling points on differently managed and utilized adjacent areas. Total content of heavy metals, i. The results indicate that concentrations of lead, nickel, chromium and mercury exceeded level below which no harmful impact of pollution TEL is noted, but none of the analyzed heavy metals exceeded the limit PEL above which harmful effects of pollution on organisms can be observed.

However, chemical analysis showed the various points exceeded the natural cobalt concentration geochemical background; 2. The reasons of cobalt concentration exceedance in natural sediments, among others, were surface runoff from fields and meadows in the form of fertilizers, plant protection products and the domestic waste water.

Full Text Available River-lake systems most often behave as hydrographic units, which undergo complex interactions, especially in the contact zone. One such interaction pertains to the role of a river in the dispersal of trace elements carried into and out of a lake. In this study, we aimed to assess the impact of rivers on the accumulation of heavy metals in bottom sediments of natural lakes comprised in postglacial river-lake systems.

The results showed that a river flowing through a lake is a key factor responsible for the input of the majority of available fraction of heavy metals Zn, Mn, Cd and Ni into the water body and for their accumulation along the flow of river water in the lake. The origin of other accumulated elements were the linear and point sources in catchments. In turn, the Pb content was associated with the location of roads in the direct catchment, while the sediment structure especially size of fraction and density could have affected the accumulation of Cr and Zn, which indicated correlations between these metals and fine fraction.

Our results suggest that lakes act as filters and contribute to the self-purification of water that flows through them. As a result, the content of most metals in lake sediments showed a decrease by approx. The increased content of two metals only, such as chromium and cadmium higher by 2. Both the content and distribution pattern of heavy metals in lake sediments are indicative of the natural response of aquatic ecosystems to environmental stressors, such as pollutant import with river water or climate change.

The complex elements creating the water ecosystem of each lake can counteract stress by temporarily removing pollutants such as toxic metals form circulation and depositing them mostly around the delta. Assessment of the governance system for the management of the East Sea-Jung dumping site, Korea through analysis of heavy metal concentrations in bottom sediments.

As with many countries, the Korea government has made a variety of efforts to meet the precautionary principle under the London Convention and Protocol acceded in and However, new strategies for the suitable marine dumping of waste materials have since been developed. Unexpectedly, most concentrations in the northern reference area N-Ref were much higher than those in the actual dumping areas G1 and G2 , may be due to the influences from nearby cities to the west of the ES-Jung site, rather than from the dumping site itself.

Additionally, heavy metal concentrations in the dredged material dumping area DMDA were found to be low although they have slightly increased over time and those in the southern reference area S-Ref were found to have gradually decreased with year.

The concentrations of most metals in the East Sea-Jung dumping site were similar to or less than those in the Earth's crust and approximately the same as those in continental. Stream sediment reflects the rock structure of the catchment area, its geochemical characteristics and possible recent contamination upstream of the sampling point and thus, it is most frequently used in geochemical researches of heavy metal pollution.

Previous geochemical studies have shown that these sediments are heavily polluted with heavy metals as a consequence of past mining of Pb-Zn ore and steelworks activities. Several problems were confronted with during EDS analysis, which are related to identification and quantification of light elements, identification of elements due to peak overlaps and quantification of spectra from unpolished samples.

These problems were successfully dealt with. These results were used for subsequent geochemical interpretation and source apportionment of heavy metals, according to associations of different heavy metal-bearing phases. By selecting same-sign dilepton and trilepton events, we estimate the sensitivity at LHC startup with the CMS detector. Regional geochemical maps of the Tonopah 1 degree by 2 degrees Quadrangle, Nevada, based on samples of stream sediment and nonmagnetic heavy -mineral concentrate.

Bottom sediment transport by radioactive tracer techniques off a stretch of the southern coast from Sao Paulo State - Brazil.

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A negative gradient was identified for mercury concentrations, from the Lerma river inlet to Alzate Reservoir dam, which demonstrates the considerable influence of the Lerma river inlet. This gradient also proves the existence of a metal recycling process between water and sediment , while the. Phytotoxic effects of bottom sediments from Ignalina NPP wastewater canals and cooler.

Samples of bottom sediments were collected from various wastewater canals of INPP, from the canal of wastewater treatment plant WWTP , small lake and rivulet, which are on the route of that wastes into Drukshiai.

In , sites of Drukshiai were observed in order to assess the phytotoxicity of its bottom sediments. The research was carried out in July of Number of somatic mutations pink, colourless and morphological and nonviable stamen hairs the quantity of whose indicates lethality, when hair contains less than 12 cells in Tradescantia clone 02 stamen hair SH system was counted. Genotoxic effect of bottom sediments on Tradescantia was estimated according to Sparrow et al.

As well as strong effect was when numbers of somatic mutations and non-viable stamen hairs exceeding 4. This test based on Magone method and lasted for 48 hours, after which time the seeds germination and root length of seedlings was measured. Estimations in both cases were run in triplicates.

It was established that in accordance with the phytotoxic impact, the wastes discharged by INPP into Drukshiai in are attributed. Phosphorus availability from bottom sediments of lakes using a nuclear technique. Availability of phosphorus from the bottom sediments of a lake plays an import role in the development of aquatic biota and in the enhancement of eutrophication process. Samples analyzed were taken from the bottom sediments of the water bodies at different sites as well as from the shores.

The method is reliable and yields information of ecological significance. Availability of phosphorus from the bottom sediments of a lake plays an import role in the development of aquatic biota and in the enhancement of the eutrophication process. In this work, the 31 P- 32 P isotopic exchange E values technique was applied to assess the potential influence of this phosphorus 'reservoir' on the water quality of the Acaray and Yguazu Dams in the Easter Region of Paraguay. Samples analyzed were taken from the bottom sediments of the water body at different sites as well as from the shores.

The method is reliable and yields information of potential ecological significance. Trace elements in bottom sediments of the Barents Sea on the standard section "Kola Meridian". Trace elements have been determined on atomic absorption spectrophotometer AA with mercury-hydride attachment HVG-1 of the company Shimadzu Japan by the methods of flaming acetylene — air and electrothermal atomization.

Common and very toxic trace elements include Pb, Cd, As, and Hg. The main sources of income in the Barents Sea are waters of the North Atlantic current and the large-scale atmospheric transport from industrialized Central Europe.

As a rule the spatial distribution of trace elements is in good agreement with the granulometric composition of bottom sediments and the content of organic carbon. The contents of most of the listed trace elements in samples of bottom sediments on the standard section "Kola Meridian" in the Norwegian classification are consistent with background levels with the exception of Ni, Cr, and As. Their content in bottom sediments at some stations has met the criteria for "slight" and "moderate" pollution.

The obtained results confirm the insignificant levels of contamination of bottom sediments of some trace elements. On the status of stocks of commercial species of aquatic biological resources, the observed levels of contamination of bottom sediments in the investigated areas of the Barents Sea will have no significant effect. Water bird characteristics, nutrient loadings, and the levels of bottom sediment silicon oxide SiO2 , aluminium oxide Al2O3 , ferric oxide Fe2O3 , calcium oxide CaO , copper Cu , phosphorus P and organic carbon C was studied in eight high altitude m small shallow 0.

Other parts are covered by estates of detached houses, barren lands and green areas. Bathymetric measurements and analyses of trace elements in bottom sediments were made in After 28 years of exploitation, reservoir's basin accumulated 43 thousand cubic metres of sediments i.

Mean annual silting rate was 0. Due to the content of copper and chromium, bottom sediments were classified to the II category sediments of average pollution according to geochemical standards. Concentrations of Pb, Cd and Hg in all analysed samples were below geochemical background. In a sample collected at the inlet to the reservoir, the TEL index for chromium was exceeded by The muddy bottom sediments of the old river beds of the lower Vistula.

The bottom sediments of these water bodies were characterized by a low water content and organic matter content expressed as a percentage of dry weight, high organic matter content expressed in units of weight, as well as a high sediment oxygen demand. Age determination of bottom sediments from Lake Hovsgol, Mongolia. Dating plays a key role in determining past environmental changes in lake sediments cores. The pIRIR ages are always younger than 14 C ages from bulk samples , however, it was possible to construct the suitable age model based on luminescence and 14 C ages.

Therefore, pIRIR protocol can be contributed to estimate the sedimentation age of lake sediments as well as 14 C dating. The U. Geological Survey, in cooperation with the U. Fish and Wildlife Service collected data on water and bottom-sediment chemistry to be used to evaluate a new water rights acquisition program designed to enhance wetland habitat in Stillwater National Wildlife Refuge and in Lahontan Valley, Churchill County, Nevada.

The area supports habitat critical to the feeding and resting of migratory birds travelling the Pacific Flyway. Information about how water rights acquisitions may affect the quality of water delivered to the wetlands is needed by stakeholders and Stillwater National Wildlife Refuge managers in order to evaluate the effectiveness of this approach to wetlands management. A network of six sites on waterways that deliver the majority of water to Refuge wetlands was established to monitor the quality of streamflow and bottom sediment.

Each site was visited every 4 to 6 weeks and selected water-quality field parameters were measured when flowing water was present. Water samples were collected at varying frequencies and analyzed for major ions, silica, and organic carbon, and for selected species of nitrogen and phosphorus, trace elements, pharmaceuticals, and other trace organic compounds.

Bottom-sediment samples were collected for analysis of selected trace elements. Dissolved-solids concentrations exceeded the recommended criterion for protection of aquatic life milligrams per liter in 33 of 62 filtered water samples. The maximum arsenic criterion micrograms per liter was exceeded twice and the continuous criterion was exceeded seven times. Criteria protecting aquatic life from continuous exposure to aluminum, cadmium, lead, and mercury 87, 0.

Mercury was the only trace element analyzed in bottom-sediment samples to exceed the published probable effect concentration 1, micrograms per kilogram. Radiocarbon dating of bottom sediments of the Red Sea. Results of radiocarbon dating of 23 cores 81 definitions sampled in the Red Sea rifton at 18 deg N are presented. Dating encompasses all major tectonic structures: the upper and the lower tectonic steps, saline scarp, axial zone.

For sediments of the upper tectonic step the normal course of sedimentogenesis is detected, in all other structures with a strongly dissected topography redeposition and nonaccumulation of sediments are widely developed. In Holocene the rate of sediment accumulation is 1. Apostolov, D. The samples were collected from the upper 5 cm layer of of the bottom sedimements together with fish from 5 points of Varna Bay and from 2 points of Saronicos Gulf in the summer of The results obtained proved to be important in investigating the ecological role of elements determined in connection with human activity in the studied area.

Earthworms can accelerate the removal of contaminants from soil. The samples of sediment were used to assess of the potential phytotoxic effect of heavy metals on higher plants. Total mortality was established in earthworms using chronic toxicity test after 7 and 28 exposure days. The largest concentration differences were recorded in the sample R7 after 7 days earthworms exposure.

Our research will continue with determination of metals concentration in earthworms. Van Metre, P. The effects of Hurricanes Katrina and Rita and the subsequent unwatering of New Orleans, Louisiana, on the sediment chemistry of Lake Pontchartrain were evaluated by chemical analysis of samples of street mud and suspended and bottom sediments. The highest concentrations of urban-related elements and compounds e. The extent of the elevated concentrations was limited, however, to within a few hundred meters of the mouth of the 17th Street Canal, similar to results of historical assessments.

Chemical and radionuclide analysis of pre- and post-Hurricane Rita samples indicates that remobilization of near-shore sediment by lake currents and storms is an ongoing process. The effects of Hurricanes Katrina and Rita on the sediment chemistry of Lake Pontchartrain are limited spatially and are most likely transitory.

Monitoring of streams: macrozoobenthos and accumulation of heavy metals and radionuclides in bottom sediments. To evaluate the environmental quality of streams in integrated monitoring sites IMS and agrostations AS , the macrozoobenthos communities and accumulation of heavy metals and radionuclides in bottom sediments were studied during Samples of macrozoobenthos were collected in stream biotopes which were recommended for monitoring.

Community biodiversity was assessed by Shannon-Wiener and Simpson indices, and water quality of streams was estimated by Trent and Mean Chandler biotic indices. Macrozoobenthos communities indicated that the studied streams were clean waters. The heavy metal concentrations in surficial sediments showed annual and seasonal changes and differences between monitoring sites. The Cu concentration in the soft turfy stream sediments at the Aukstaitija IMS was twice as high as that in sediments of other monitoring streams with hard sandy-gravel bottoms.

During , the Ni concentration decreased, while levels of Cu, Cd and Cr were relatively stable. The concentration of Cs was relatively stable in agrostation streams. Compared to levels in , an increase of Cs activity was observed in sediments at the Dzuklija IMS during Common and very toxic trace elements incl Impact of bottom trawling on sediment characteristics - A study along inshore waters off Veraval coast, India.

The present communication is a study on the impact of bottom trawling on the sediment characteristics along Veraval coast, which is the largest trawler port of India. Experimental bottom trawling was conducted from MFV Sagarkripa at five transects Gamma-emitting radionuclides in the bottom sediments of some Finnish lakes. In and bottom sediment and surface water samples were taken from eight large lakes representing all five categories of deposition regions contaminated by the chernobyl fallout in Finland.

All samples were analysed for gamma-emitting radionuclides. The other radionuclides of Chernobyl origin detected in water samples were Ru, Sb and Cs. The maximum values were in Lake Pyhaejaervi. In addition to the cesium isotopes Cs and Cs , Chernobyl derived Ru, Sb amd Ce were detected i the surface layer of sediment in most lakes. In the maximum concentrations of Cs and Cs were in the uppermost layer of sediment cm at almost all stations.

In , the cesium peaks already occurred at many stations in the second slice cm , which may indicate downward diffusion of cesium in sediments or mixing of sediment layers during sampling. The most important factors affecting cesium values in sediments were the local amount of deposition and the type of sediment. This study did not reveal any correletion between the maximum depth of the lake and the area of the lake with the cesium amounts in the sediments.

Heavy metal concentrations in Bottom Sediments of Ikpoba River Jun 23, Eichornia crassipes. This station was the lowest in depth during the dry season. The water level however increased when it was heavily flooded during the rainy season. Activities here include making of sacrifices. Sediment Samples Collection, Preparation Nannofossils in upper quaternary bottom sediments of back-arc basins in the southwestern Pacific. The content of coccoliths and their taxonomic composition indicate warm subtropical-tropical conditions.

Long cores demonstrate a decrease in species diversity reflecting the transition from the cold late Pleistocene to the Holocene. Sediment on the bottom of the water has been considered one of the water pollutants in the environmental management of Korea so treated as a management on pollutants, as you can see the examples in the dragging operation in the polluted sea area.

To healthily maintain and conserve the water ecosystem including bottom living things in the water, sediment on the bottom of the water should be recognized as the independent medium, which should maintain the certain quality like the water, the atmosphere, and soil, rather than the source of water pollution. Such recognition means that the management of sediment on the bottom of the water should change the fragmentary goal, centered the post management focusing on the water management, to the ecosystematic goal including the bottom living things.

In a point of the view, this study has a great significance to suggest not only the final goal for the management of sediment on the bottom of the water but also the necessity of developing the environmental standard of the sediment on the bottom of the water, which is a standard of the management or judgment in the actual managing the sediment on the bottom of the water - an estimation on the pollution of sediment , a removal of the polluted sediment , a purification of sediment , and an abandonment of the dragged sediment -, and the development measures.

Considering the situation that even the basic scheme related to the management of sediment is not prepared in the Government level, the concept of the environmental standard of sediment , the foreign example of the environmental standard of sediment , the current state of the domestic sediment pollution, and the development scheme of the environmental standard in this study must be the important foundation to establish the management system of sediment in the Government level.

Influence of break structures on the distribution of radionuclides in bottom sediments of the Kyiv reservoir. We study the distribution of radionuclides in bottom sediments of the Kyiv reservoir on the basis of research of adjacent territory break - block structures with deciphering space-born images and ground measurements and forecast the occurrence of extreme situations due to the redistribution of bottom water flows and sediments of radionuclides.

Dynamics of fluctuations of Cs contents in the bottom sediment in limnetic dam reservoir Goczalkowice. The results of Cs studies in bottom sediment in the Goczalkowice reservoir are presented. The determined coefficients of aquatic migration, difusion in bottom sediment and water in vertical section confirm zonal nature of Cs occurrance and accumulation in the reservoir. Anthropogenic radionuclide fluxes and distribution in bottom sediments of the cooling basin of the Ignalina Nuclear Power Plant.

Samples of bottom sediments from seven monitoring stations within the cooling basin were collected in — and — in July—August. The lowest Cs activity concentrations were obtained for two stations that were situated close to channels with radionuclide discharges, but with sediments that had a significantly smaller fraction of organic matter related to finest particles and consequently smaller radionuclide retention potential.

The Cs activity concentration was distributed quite evenly in the bottom sediments from other investigated monitoring stations. Higher 60 Co and 54 Mn activity concentrations were observed in the monitoring stations that were close to the impact zones of the technical water outlet channel and industrial rain drainage system channel. The vertical distribution of radionuclides in bottom sediments revealed complicated sedimentation features, which may have been affected by a number of natural and.

The average concentrations of Pb and Cu were In this study, the concentrations were significantly higher near the mouth river and declined as the sampling points were further away from the estuary. Generally, the concentrations of heavy metals were relatively low when compare with other studies in Malaysia. However, the calculated enrichment factors EF obtained for Pb, has a slightly higher value, and was probably influenced by anthropogenic input.

The concentration for both metals increased with the decrease of mean size, suggesting their association with the fine fraction of the sediments. Geomorphological condition and sea bottom sediment characteristics of Sebagin coast for NPP site evaluation in South Bangka. Study on geomorphological condition and sea bottom sediment in the coastal area of Sebagin, South Bangka Regency, Bangka Belitung Province has been performed.

Geomorphological of the seabed was valuable to identify geological structures that exist on the seabed layers. Whereas, sediments seabed characteristics was useful to provide portrait of seabed layer due to the stability of NPP site concerning the seismic aspect and the determination of water intake position. The objective of the study was to evaluate geomorphological condition and sea bed sediment characteristics in the South Bangka sea.

The result of the study showed that the study area was a shallow water sea with a depth range of m. Geomorphological profile of the sea bed tend to be irregular and based on the seismic interpretation, there were no fault exists. Result analysis on the sea bottom sediment showed that clay distribution dominated the study area.

Presence of selected chemicals of emerging concern in water and bottom sediment from the St. Louis River, St. The St. Louis Bay of Lake Superior receives substantial urban runoff, wastewater treatment plant effluent, and industrial effluent. In , the International Joint Commission designated the St. Louis Bay portion of the lower St. Concerns exist about the potential effects of chemicals of emerging concern on aquatic biota because many of these chemicals, including endocrine active chemicals, have been shown to affect the endocrine systems of fish.

To determine the occurrence of chemicals of emerging concern in the St. Louis River, the St. Louis Bay, and Superior Bay, the U. Geological Survey in cooperation with the Minnesota Pollution Control Agency and the Wisconsin Department of Natural Resources collected water and bottom-sediment samples from 40 sites from August through October The objectives of this study were to 1 identify the extent to which chemicals of emerging concern, including pharmaceuticals, hormones, and other organic chemicals, occur in the St.

Louis Bay, and Superior Bay, and 2 identify the extent to which the chemicals may have accumulated in bottom sediment of the study area. Samples were analyzed for selected wastewater indicators, hormones, sterols, bisphenol A, and human-health pharmaceuticals. During this study, 33 of 89 chemicals of emerging concern were detected among all water samples collected and 56 of chemicals of emerging concern were detected in bottom-sediment samples.

The chemical N,N-diethyl-meta-toluamide DEET was the most commonly detected chemical in water samples and 2,6-dimethylnaphthalene was the most commonly detected chemical in bottom-sediment samples. In general, chemicals of emerging concern were detected at a higher frequency in bottom-sediment samples than in water samples. Estrone a steroid hormone and hexahydrohexamethyl cyclopentabensopyran a synthetic fragrance were the most commonly detected endocrine active chemicals in.

Sedimentation and occurrence and trends of selected nutrients, other chemical constituents, and cyanobacteria in bottom sediment , Clinton Lake, northeast Kansas, A combination of available bathymetric-survey information and bottom-sediment coring was used to investigate sedimentation and the occurrence of selected nutrients total nitrogen and total phosphorus , organic and total carbon, 25 trace elements, cyanobacterial akinetes, and the radionuclide cesium in the bottom sediment of Clinton Lake, northeast Kansas.

The total estimated volume and mass of bottom sediment deposited from through in the conservation multi-purpose pool of the reservoir was million cubic feet and 18 billion pounds, respectively. The estimated sediment volume occupied about 8 percent of the conservation-pool, water-storage capacity of the reservoir.

Sedimentation in the conservation pool has occurred about 70 percent faster than originally projected at the time the reservoir was completed. Water-storage capacity in the conservation pool has been lost to sedimentation at a rate of about 0. Mean annual net sediment deposition since in the conservation pool of the reservoir was estimated to be million pounds per year. Mean annual net sediment yield from the Clinton Lake Basin was estimated to be 1.

Typically, the bottom sediment sampled in Clinton Lake was at least 99 percent silt and clay. The mean annual net loads of total nitrogen and total phosphorus deposited in the bottom sediment of Clinton Lake were estimated to be 1. The estimated mean annual net yields of total nitrogen and total phosphorus from the Clinton Lake Basin were 3, pounds per square mile per year and 1, pounds per square mile per year, respectively. Throughout the history of Clinton Lake, total nitrogen concentrations in the deposited sediment generally were uniform and indicated consistent inputs to the reservoir over time.

Likewise, total phosphorus concentrations in the deposited sediment generally were uniform. Heavy metals are naturally presented in different chemical bonds within sediment. Different factors affect metals bonding in sediment. One of those factors is changing in Redox potential. In the present study the effect of redox potential on fractionation and bonding of metals within Anzali international wetland bottom sediment is investigated.

Sediment samples of Anzali wetland were aerated for one month and redox potential and p H was measured at 0, 1, 7, 21, and 28th days. Subsamples of sediments at mentioned days of experiments were taken and analyzed for Cu, Zn, Ni, and Cr for deferent chemical bonds using sequential extraction analysis.

Nickel and Cr were mostly associated in hard residual bonds. Strontium in the bottom sediments of some Finnish lakes. The maximum values occurred in Lake Naesijaervi. The local amount of deposition and the type of sediment were the most important factors affecting strontium values in sediments. At some stations there was a clear maximum in a deeper sediment layer, which could be construed as a marker of the nuclear weapons tests in the s.

The effect of bottom sediment supplement on heavy metals content in plants Zea mays and soil. Full Text Available Important aspect of bottom sediments is the problem of their management or disposal after their extraction from the bottom of rivers, dam reservoirs, ports, channels or ponds.

The research aimed at an assessment of potential environmental management of bottom sediment used as an admixture to light soil basing on its effect on contents of heavy metals in plants and soil. The research was conducted on light soil with granulometric structure of weakly loamy sand.

The sediment applied in the presented research revealed high share of silt and clay fractions, alkaline pH and low contents of heavy metals, therefore it may be used as an admixture to the above mentioned soils to improve their productivity.

The applied bottom sediment to the soil affected a decreased in Zn, Cd and Pb content in maize in comparison with the treatment without the deposit whereas increased content of Cu, Cr and Ni. No exceeded permissible content of heavy metals concerning plant assessment in view of their forage usability were registered in maize biomass.

Uranium isotopes in waters and bottom sediments of rivers and lakes in Poland. Activity concentrations of U, U and U were determined in waters and bottom sediments in two main rivers in Poland the Vistula and Odra rivers with their tributaries, in four coastal rivers and six lakes. Concentration of U and U were compared with the concentrations of Ra determined in another study.

As compared with concentrations in coastal rivers and in lakes, enhanced concentrations of the radionuclides were observed in water and bottom sediments in the upper and middle courses of Vistula river, whereas in the Odra river the enhanced concentrations were present only in the bottom sediments. The enhanced concentrations in the Vistula river result from the discharge of coal mine waters from the Upper Silesian Coal Basin, and they indicate that the discharge was continued.

The enhanced concentration in Odra river observed only in bottom sediments indicate that the discharge occurred in the past. Radioactive pollution of the Chernobyl cooling pond bottom sediments. Distribution of Cs, Am, 90Sr in a solid phase. Full Text Available The second part of complex research of the Chernobyl cooling pond bottom sediments are presented Data about vertical distribution of radioactive pollution Cs, Am, 90Sr in a solid phase of sediments are received. Distribution coefficients Cs and 90Sr, selectivity coefficients of their exchange with similar cations and physical-chemical forms are defined.

Results of research of radionuclide chemical recovery from the sediment samples are analyzed. Accumulation and potential dissolution of Chernobyl-derived radionuclides in river bottom sediment. Areas contaminated with radionuclides from the Chernobyl nuclear accident have been identified in Pripyat River near the Chernobyl Nuclear Power Plant.

Several nuclear fuel particles have been preserved at cm depth that is the peak area of the concentrations of the radionuclides. Th ese inventories in the bottom sediments were compared with those of the released radionuclides during the accident. An analysis using a selective sequential extraction technique was applied for the radionuclides in the sediments.

Results suggest that the possibility of release of Cs and , Pu from the bottom sediment was low compared with 90 Sr. The potential dissolution and subsequent transport of 90 Sr from the river bottom sediment should be taken into account with respect to the long-term radiological influence on the aquatic environment. Full Text Available Currently, prospecting and design-related works are performed prior to the upcoming launch of mining operations at Klen gold and silver deposit in Chukot Autonomous District.

The anthropogenic impact of the geological exploration in this intact territory has been produced since A considerable amount of borehole drilling, prospecting, road building, and temporary housing development has been performed.

The engineering research, including ecological surveys, has been completed to assess the ecological impact of upcoming exploratory and mining operations at the deposit. Assessment of the geochemical condition of the landscape constituents, including the soil, ground and bottom sediments is of special importance in terms of their engineering protection and rational management of the natural environment.

The analysis of the chemical pollution of soils, ground and bottom sediments is based on the examination of 30 samples. Peculiarities of the chemical composition of samples extracted at the deposit were identified. It has been discovered that pH values of the soil vary from 5.

The concentration of metal in bottom sediments exceeds its concentration in the soil by far. Almost all irregular features of the sample water in the whole territory of the deposit are caused by the anthropogenic impact. In general, the metal content in soils, ground and bottom sediments within the territory of the deposit is slightly different from the regular clarke.

P and organic carbon C was Use of geochemical biomarkers in bottom sediment to track oil from a spill, San Francisco Bay, California. The oil flowed into Carquinez Strait and Suisun Bay in northern San Francisco Bay Sediment and oil samples were collected within a week and analysed for geochemical marker compounds in order to track the molecular signature of the oil spill in the bottom sediment.

Identification of the spilled oil in the sediment was complicated by the degraded nature of the oil and the similarity of the remaining, chromatographically resolvable constituents to those already present in the sediments from anthropogenic petroleum contamination, pyrogenic sources, and urban drainage.

Ratios of hopane and sterane biomarkers, and of polycyclic aromatic hydrocarbons and their alkylated derivatives best identified the oil impingement. They showed the oil impact at this early stage to be surficial only, and to be patchy even within an area of heavy oil exposure.

Enhanced particle fluxes and heterotrophic bacterial activities in Gulf of Mexico bottom waters following storm-induced sediment resuspension. Ziervogel, K. Bottom nepheloid layers BNLs in the deep sea transport and remobilize considerable amounts of particulate matter, enhancing microbial cycling of organic matter in cold, deep water environments.

We measured bacterial abundance, bacterial protein production, and activities of hydrolytic enzymes within and above a BNL that formed in the deep Mississippi Canyon, northern Gulf of Mexico, shortly after Hurricane Isaac had passed over the study area in late August A large fraction of the suspended matter in the BNL consisted of resuspended sediments , as indicated by high levels of lithogenic material collected in near- bottom sediment traps shortly before the start of our sampling campaign.

To investigate the effects of enhanced particle concentrations on bacterial activities in deep BNLs more directly, we conducted laboratory experiments with roller bottles filled with bottom water and amended with experimentally resuspended sediments from the study area. Macroaggregates formed within 1 day from resuspended sediments ; by day 4 of the incubation bacterial cell numbers in treatments with resuspended sediments were more than twice as high as in those lacking sediment suspensions.

Cell-specific enzymatic activities were also generally higher in the sediment. Sampling marine sediments for radionuclide monitoring. A description of the most common devices used for sampling marine sediments are reported.

The systems are compared to evidence their intrinsic usefulness, for collecting samples in different environmental conditions or with different scientific objectives. Perturbations and artifacts introduced during the various steps of the sampling procedure are also reviewed, and suggestions are proposed for obtaining and preserving, as much as possible, the representativeness of the sediment samples. Assessment of stream bottom sediment quality in the vicinity of the Caldas uranium mine.

Oliveira, Priscila E. Laboratorio de Pocos de Caldas. In order to perform the research, twelve sampling stations were established in the watersheds around Caldas UMMF: the Soberbo creek, the Consulta brook, and the Taquari river. One of the stations was located inside the Bacia Nestor Figueiredo, a retention pond that receives effluents from WRP4, and another in a settling tank D2 for radium, which receives the effluents from TD.

Detailed investigation in sub-superficial layers is recommended at these locations to evaluate the need of implementing mitigation actions such as lining and constructing hydraulic barriers downstream the ponds. Stream sediment sampling and analysis. Final report. The objectives were to sample and analyze sediments from upstream and downstream locations relative to the Goodyear Atomic plant site of three streams for selected pollutants.

Systematic sampling for suspended sediment. Abstract - Because of high costs or complex logistics, scientific populations cannot be measured entirely and must be sampled. Accepted scientific practice holds that sample selection be based on statistical principles to assure objectivity when estimating totals and variances. Probability sampling --obtaining samples with known probabilities--is the only method that Occurance of geophilic of keratinophilic fungi in bottom sediments of lakes of various trophicity.

Full Text Available The present investigations proved that colonization of bottom sediments with geophilie kerationophilic fungi in lakes of different trophicity was conditioned by the organic matter content. There was a relationship between occurrence of microorganisms and the basin management method. The greatest concentration of keratinophilic fungi where species typical of sewages polluted with them dominated was found in sediments of a basin used for recreation.

In sediments of a lake located in the agricultural region there was a domination of species charakteristic of pure water in respect to sanitary regulations. The behavior of dissolved forms of Mn and Fe is considered from the viewpoint of their different solubility and formation of sulfides.

The redox system of the Black Sea sediments can significantly be expanded at the expense of the migration methane and hydrogen, which accompanies its anaerobic oxidation. River bottom sediment from the Vistula as matrix of candidate for a new reference material. Bottom sediments are very important in aquatic ecosystems. The sediments accumulate heavy metals and compounds belonging to the group of persistent organic pollutants.

For the matrix of candidate of a new reference material, moisture content, particle size, loss on ignition, pH, and total organic carbon were determined. For the candidate for a new reference material, homogeneity and analytes content were determined using a validated method.

The results are a very important part of the development and certification of a new reference materials. Full Text Available Stability analysis of a levee made of the bottom sediments from Czorsztyn-Niedzica Reservoir is presented in the paper. These sediments were classified as silty sands and, based on the authors' own research, their geotechnical parameters were beneficial, so the possibility of using this material for the hydraulic embankments was considered. Stability and filtration calculations were carried out for a levee that had the same top width - 3 m, slope inclinations and different heights: 4, 6 and 8 m.

Two methods were used: analytical and numerical. Calculations were carried out without and with a steady and unsteady seepage filtration. Based on the analysis carried out it was stated that the levee made of the bottom sediments is stable even at the height of 8. Bottom currents and sediment waves on a shallow carbonate shelf, Northern Carnarvon Basin, Australia. The modern seafloor of the Australian Northwest Shelf between Exmouth and Dampier was analyzed for large scale sedimentary bedforms on 3D seismic reflection data.

The Carnarvon MegaSurvey of Petroleum Geo-Services PGS , a merged dataset of multiple industrial 3D seismic reflection surveys with a total size of 49, km2, offers an extensive view of the continental shelf, slope and rise of the Northern Carnarvon Basin. Over the shelf two fields of large scale sediment waves were observed in water depths between m, where the seafloor may be influenced by different processes including internal waves, tides and storms.

Based on the dimensions and orientations of the sediment waves the dominant direction and approximate strength of local bottom currents could be estimated. Information on local sediment grain-size distribution was provided by the auSEABED database allowing a classification of the observed sediment waves into sand- or mudwaves.

The first sediment wave field is positioned northwest of the Montebello Islands where the shelf is comparatively narrow and local sediment is mainly sand-sized. It most likely formed by increased bottom currents induced by the diversion of tidal flows around the islands. The second sediment wave field is located north of the Serrurier and Bessieres Islands within a local seafloor depression.

Local sediments are poorly sorted, containing significant amounts of mud and gravel in addition to the mainly sand-sized grains. The coarser sediment fraction could have been reworked to sandwaves by cyclone-induced bottom currents. Alternatively, the finer sediment fraction could form mudwaves shaped by less energetic along-slope oriented currents in the topographic depression.

The sediment waves consist partially of carbonate grains such as ooids and peloids that formed in shallow water during initial stages of the post glacial sea-level rise. These stranded carbonate grains thus formed in a different environment than the sediment. Reconstructing bottom water temperatures from measurements of temperature and thermal diffusivity in marine sediments.

Continuous monitoring of oceanic bottom water temperatures is a complicated task, even in relatively easy-to-access basins like the North or Baltic seas. Here, a method to determine annual bottom water temperature variations from inverse modeling of instantaneous measurements of temperatures and sediment thermal properties is presented.

This concept is similar to climate reconstructions over several thousand years from deep borehole data. However, in contrast, the presented method aims at reconstructing the recent temperature history of the last year from sediment thermal properties and temperatures from only a few meters depth. For solving the heat equation, a commonly used forward model is introduced and analyzed: knowing the bottom water temperature variations for the preceding years and the thermal properties of the sediments , the forward model determines the sediment temperature field.

The bottom water temperature variation is modeled as an annual cosine defined by the mean temperature, the amplitude and a phase shift. As the forward model operator is non-linear but low-dimensional, common inversion schemes such as the Newton algorithm can be utilized.

The algorithms are tested for artificial data with different noise levels and for two measured data sets: from the North Sea and from the Davis Strait. Both algorithms used show stable and satisfying results with reconstruction errors in the same magnitude as the initial data error. In particular, the artificial data sets are reproduced with accuracy within the bounds of the artificial noise level. Natural and artificial radionuclides in the Suez Canal bottom sediments and stream water.

The activity concentrations of U series, Th series and 40 K did not exceed The activity concentration of U series and 40 K did not exceed 0. The activity concentrations of U series, Th series and 40K did not exceed The activity concentration of U series and 40K did not exceed 0. Forty-four sediment samples were collected from 28 locations in the Hanford Reach of the Columbia River to assess the presence of metals and man-made radionuclides in the near shore and shoreline settings of the Hanford Site.

Three locations were sampled upriver of the Hanford Site plutonium production reactors. Twenty-two locations were sampled near the reactors. Three locations were sampled downstream of the reactors near the Hanford Townsite. Sediment was collected from depths of 0 to 6 in. Contamination by arsenic, chromium, copper, lead, and zinc was found.

Man-made radionuclides occur in all samples except four collected opposite the Hanford Townsite. Determination of solid flow for bottom sediment drag of Parana river using tracer techniques. Radioactive tracing technique with labeled sand was employed to evaluate the bottom sediment drag of Parana River, near Guaira City, State of Parana.

Dubai creek can be considered as the focal point of Dubai. It has great importance for trading and aesthetic values. Total and leachable heavy metals Cd, Co, Ni, Pb and Zn , organic carbon and total carbonate were studied in the bottom sediments of the creek. Pollution Load Index, statistical analysis, were used in order to quantify the pollution load as well as to discriminate the data into significant groups.

Normalization of the data using organic carbon and total carbonate was done in or Passive sampling methods for contaminated sediments. Passive sampling methods PSMs for estimating Cfree offer the potential for cost-efficient and accurate in situ characterization The increase of 9 0Sr concentrations in the Black Sea bottom sediments along to western coast of the Black Sea and south part of Crimea was observed in years.

To our opinion, it was connected with hydrological processes for example, currents , occurring in the given sea parts. The most polluted by post-Chernobyl 9 0Sr areas were bottom sediments of Dnieper, Dniester and Danube River deltas, territory of an arrangement of a main channel of the North-Crimea Channel - region of a peninsula Tarkhankut, southeast part of Crimea Feodosiya area.

The similar situation in confined of the greatest contents 9 0Sr to the specified areas not only is kept with time till , but the process of increase of 9 0Sr concentration in bottom sediments of the investigated regions is observed. So average concentration of 9 0Sr in Dnieper River delta bottom sediments in was 28,5 Bq kg - 1 , in - ,2 28,5 Bq kg - 1 of Dry Weight. Such character of 9 0Sr redistribution shows, that both in first years after Chernobyl NPP accident, and in the following time, the entry of 9 0Sr in the Black Sea basin occurs, basically, with water flow of the large rivers in a northwest part of the Black Sea, discharge waters of the North-Crimean Channel.

These sources of 9 0Sr input to the Black Sea ecosystem considerably prevailed above direct atmospheric pollution by given radionuclide in April-May at once after the Chernobyl NPP accident. On the base of monitoring researches results the maps of 9 0Sr dynamics redistribution in the Black Sea bottom sediments cm since Chernobyl NPP accident up to were sketched out.

The distribution of 9 0Sr radionuclide in the bottom sediments columns, which were selected from the Corukh river mouth region and from the Dnieper-Bug estuary area, is investigated. The peaks of 9 0Sr increased contents were founded in the profile of its vertical distribution in the bottom sediments. These peaks correspond to the periods of 9 0Sr.

Content and the forms of heavy metals in bottom sediments in the zone of industrial pollution sources ,. Full Text Available Regularities in the distribution of heavy metals in sediments in the zone of influence of the steel industry in Mariupol are installed.

Ecological and geochemical assessment of sediment contamination by heavy metals is performed. The main sources of pollution of bottom sediments are air borne emissions from industrial plants, hydrogenous pollution in industrial sewage entering the water, sewage sludge, ash dumps, slag, ore, sludge, oil spills and salt solutions. Pollution hydrogenous sediments may be significant, contaminated sediments are a source of long-term contamination of water, even after cessation of discharges into rivers untreated wastewater.

The environmental condition of bottom sediments in gross content of heavy metals is little information because they do not reflect the transformation and further migration to adjacent environment. The study forms of giving objective information for ecological and geochemical evaluation. The study forms of heavy metals in the sediments carried by successive extracts. Concentrations of heavy metals in the extracts determined by atomic absorption spectrometer analysis CAS It was established that a number of elements typical of exceeding their content in bottom sediments of the background values, due likely to their technogenic origin.

Man-made pollution of bottom sediments. Mariupol has disrupted the natural form of the ratio of heavy metals. In the studied sediments form ion exchange increased content of heavy metals, which contributes to their migration in the aquatic environment. Hydrography and bottom boundary layer dynamics: Influence on inner shelf sediment mobility, Long Bay, North Carolina. This study examined the hydrography and bottom boundary-layer dynamics of two typical storm events affecting coastal North Carolina NC ; a hurricane and the passages of two small consecutive extratropical storms during November Both instruments profiled the overlying water column in 0.

Simultaneous measurements of wind speed and direction, wave and current parameters, and acoustic backscatter were coupled with output from a bottom boundary layer bbl model to describe the hydrography and boundary layer conditions during each event. The bbl model also was used to quantify sediment transport in the boundary layer during each storm.

Both study sites exhibited similar temporal variations in wave and current magnitude, however, wave heights during the November event were higher than waves associated with the hurricane. Near- bottom mean and subtidal currents, however, were of greater magnitude during the hurricane. Substantial spatial variations in sediment transport existed throughout both events. During both events, along-shelf sediment transport exceeded across-shelf transport and was related to the magnitude and direction of subtidal currents.

Given the variations in sediment type across the bay, complex shoreline configuration, and local bathymetry, the sediment transport rates reported here are very site specific. However, the general hydrography associated with the two storms is representative of conditions across northern Long Bay. Since the beaches in the study area undergo frequent renourishment to counter the effects of beach erosion, the results of this study also are relevant to coastal.

Geological Survey, in cooperation with the Colorado Department of Public Health and Environment, conducted a study to investigate environmental factors that may contribute to the bioaccumulation of mercury in two Front Range reservoirs. One of the reservoirs, Brush Hollow Reservoir, currently has a fish-consumption advisory for mercury in walleye Stizostedion vitreum , and the other, Pueblo Reservoir, which is nearby, does not. Water, bottom sediment , and zooplankton samples were collected during and , and a sediment -incubation experiment was conducted in Total mercury concentrations were low in midlake water samples and were not substantially different between the two reservoirs.

The only water samples with detectable methylmercury were collected in shallow areas of Brush Hollow Reservoir during spring. Mercury concentrations in reservoir bottom sediments were similar to those reported for stream sediments from unmined basins across the United States. Despite higher concentrations of fish-tissue mercury in Brush Hollow Reservoir, concentrations of methylmercury in sediment were as much as 3 times higher in Pueblo Reservoir.

Mercury concentrations in zooplankton were at the low end of concentrations reported for temperate lakes in the Northeastern United States and were similar between sites, which may reflect the seasonal timing of sampling. Factors affecting bioaccumulation of mercury were assessed, including mercury sources, water quality, and reservoir characteristics.

Atmospheric deposition was determined to be the dominant source of mercury; however, due to the proximity of the reservoirs, atmospheric inputs likely are similar in both study areas. Water-quality constituents commonly associated with elevated concentrations of mercury in fish pH, alkalinity, sulfate, nutrients, and dissolved organic carbon did not appear to explain differences in fish-tissue mercury concentrations between the reservoirs. Low methylmercury. Influence of environmental and anthropogenic factors at the bottom sediments in a Doce River tributary in Brazil.

In developing countries, it is uncommon to find watersheds that have been the object of detailed environmental studies. Cytological maps of lampbrush chromosomes of European water frogs Pelophylax esculentus complex from the Eastern Ukraine. Background Hybridogenesis hemiclonal inheritance is a kind of clonal reproduction in which hybrids between parental species are reproduced by crossing with one of the parental species.

European water frogs Pelophylax esculentus complex represent an appropriate model for studying interspecies hybridization, processes of hemiclonal inheritance and polyploidization. Parental and hybrid frogs can reproduce syntopically and form hemiclonal population systems. For studying mechanisms underlying the maintenance of water frog population systems it is required to characterize the karyotypes transmitted in gametes of parental and different hybrid animals of both sexes.

Results In order to obtain an instrument for characterization of oocyte karyotypes in hybrid female frogs , we constructed cytological maps of lampbrush chromosomes from oocytes of both parental species originating in Eastern Ukraine. We further identified certain molecular components of chromosomal marker structures and mapped coilin-rich spheres and granules, chromosome associated nucleoli and special loops accumulating splicing factors.

We recorded the dissimilarities between P. Satellite repeat RrS1 was mapped in centromere regions of lampbrush chromosomes of the both species. Additionally, we discovered transcripts of RrS1 repeat in oocytes of P. Moreover, G-rich transcripts of telomere repeat were revealed in association with terminal regions of P.

Conclusions The constructed cytological maps of lampbrush chromosomes of P. The effect of water samples with different structural states on some physiological indices of white laboratory rats, 5 groups of 10 animals 5 females and 5 males and frogs has been studied.

The investigation was performed for 1 month. For the determination of the content of liquid crystal associates LCA in water samples there was used the dilatometric method, the performance of experimental animals was studied by the swimming test up to total fatigue. The performed experiment on growing rats with the use of water with varying degrees of structuredness showed that according to the weight gain there were optimal water "Lekor" and tap water , treated with Bioptron the content of the structured fraction is 5.

On physical performance the best indices were in animals consumed water treated with the Bioptron lamp. In performance of experiments on frogs it was found that cardiac function in animals under experimental conditions over time weakens spontaneously: heart rate and cardiac output decline. Therefore, the effect of different water samples on the cardiac function was assessed on the intensity of its decrease for 15 minutes.

In the experimental study of the effect of water with different content of LCA on heart rate and cardiac output of the frog it was found that the optimum level of structuredness of water is within the range of 5. All the other water samples, the content of nanocrystals in which was below or above this range, has a pronounced inhibitory effect on the heart performance of the frog.

Effects of oil sands waste water on the wood frog rana sylvatica. The sustainability of various reclamation strategies can be determined by the growth and health of indigenous amphibians Wood Frogs. This paper referred to the large quantities of tailings water that are generated by oil sand extraction activities. It presented the results of a study that was conducted in the spring and summer of and on reclaimed formation wetlands comprising tailings water.

The objective was to understand the impact of these wetlands on native amphibians. Six experimental trenches were made at one site in the first year. Each trench had 3 enclosures with 50 tadpoles. In the second year, there were 13 sites, including 6 reference and 7 OSPW affected sites, which were classified as old more than 8 yrs or young less than 7 yrs.

Four enclosures, with 50 tadpoles each, were placed in each wetland. The study involved the evaluation of growth rate, survival, time to metamorphosis, thyroid hormone concentrations, liver EROD activity, and tissue retinol concentrations. In addition, stable isotopes were used to track carbon flow from primary production plants, through the food chain, to tadpoles and frogs which represent intermediate and higher trophic levels in reclaimed wetlands.

Bioaccumulation of polychlorinated biphenyls in ranid frogs and northern water snakes from a hazardous waste site and a contaminated watershed. Livers of bullfrogs Rana catesbeiana from a polychlorinated biphenyl PCB contaminated watershed and hazardous waste site located in Pickens County, South Carolina, contained significantly higher concentrations of PCBs 2.

Green frogs R. No temporal variation was observed in PCB concentrations of bullfrogs or green frogs from the contaminated sites between and Levels of PCBs in the livers of northern water snakes Nerodia sipedon were significantly higher in snakes from the contaminated watershed When compared to frogs , significantly higher bioaccumulation occurred in water snakes from the contaminated watershed.

No significant differences in PCB levels were found with respect to sex or body size snout-vent length SVL or body mass for frogs or snakes. PCBs were detected also in eggs of both frogs and snakes. European hotspots as evidenced by the Palearctic distribution of songbirds.

A database has been created of digitized equal area distribution maps of 2, phylogenetic species of songbirds endemic to the Palearctic Region. Geographic distribution of species richness delineated several hotspot regions in the Palearctic , mostly located in mountainous areas.

The index of. Densities of Palearctic warblers and Afrotropical species within the Densities of Palearctic warblers and Afrotropical species within the same guild in Sahelian West Africa. Jared M Wilson, Will Cresswell. Declines in populations of Palearctic migrants wintering in the Sahel of Africa have been linked to the impacts of climate change and habitat degradation in the region. Despite this Strategies of water conservation in southern African frogs.

The three approaches which anurans have adopted in response to water Discovery of alien water frogs gen. Pelophylax in Umbria, with first report of P. Directory of Open Access Journals Sweden. Full Text Available Allochthonous water frogs gen. Pelophylax have been repeatedly introduced in several European countries, causing dramatic consequences for the conservation of indigenous taxa.

In Italy, invasive populations are known for northern regions, where they were introduced mainly for edible and scientific purposes. Here, we report the first detection of an alien population of water frogs in Central Italy, along the Resina valley Umbria. Genetic analysis of the mitochondrial ND3 gene polymorphism assigned some specimens to two different Pelophylax ridibundus clades widespread in Central and Eastern Europe. By contrast, two samples matched the mitochondrial DNA mtDNA sequence of Pelophylax lessonae bergeri, an autochthonous taxon widespread in Central Italy, suggesting possible hybridization between alien and indigenous frogs.

Finally, the specific haplotype of Pelophylax shqipericus, the Albanian Pool Frog , was also identified according to mtDNA polymorphism. This record, firstly reported for Italy, poses concerns for the conservation of this cryptic taxon, suggesting that international water frog trade may involve also particularly endangered species. Effects of water management, connectivity, and surrounding land use on habitat use by frogs in rice paddies in Japan.

In Japan, rice paddies play an important role as a substitute habitat for wetland species, and support rich indigenous ecosystems. However, since the s, agricultural modernization has altered the rice paddy environment, and many previously common species are now endangered. It is urgently necessary to evaluate rice paddies as habitats for conservation.

Among the species living in rice paddies, frogs are representative and are good indicator species, so we focused on frog species and analyzed the influence of environmental factors on their habitat use. We found four frog species and one subspecies Hyla japonica, Pelophylax nigromaculatus, Glandirana rugosa, Lithobates catesbeianus, and Pelophylax porosa brevipoda at our study sites in Shiga prefecture. For all but L. We constructed generalized additive mixed models with survey date as the smooth term and applied Akaike's information criterion to choose the bestranked model.

Because life histories and biological characteristics vary among species, the factors affecting habitat use by frogs are also expected to differ by species. We found that both breeding and non-breeding habitat uses of each studied species were influenced by different combinations of environmental factors and that in most cases, habitat use showed seasonality.

For frog conservation in rice paddies, we need to choose favorable rice paddy in relation to surrounding land use and apply suitable management for target species. Water balance of field-excavated aestivating Australian desert frogs , the cocoon-forming Neobatrachus aquilonius and the non-cocooning Notaden nichollsi Amphibia: Myobatrachidae.

Burrowed aestivating frogs of the cocoon-forming species Neobatrachus aquilonius and the non-cocooning species Notaden nichollsi were excavated in the Gibson Desert of central Australia. Their hydration state osmotic pressure of the plasma and urine was compared to the moisture content and water potential of the surrounding soil.

The non-cocooning N. While this sand had favourable water potential properties for buried frogs , the considerable spatial and temporal variation in sand moisture meant that frogs were not always in positive water balance with respect to the surrounding soil. The cocoon-forming N. Cocoons of excavated frogs ranged in thickness from Cocooned claypan N.

By contrast, non-cocooned N. Both species had similar plasma arginine vasotocin AVT concentrations ranging from 9. For both species, AVT showed no relationship with plasma osmolality over the lower range of plasma osmolalities but was appreciably increased at the highest osmolality recorded. This study provides the first evidence that cocoon formation following burrowing is not obligatory in species that are capable of doing so, but that cocoon formation occurs when soil water conditions are more desiccating than for non-cocooned frogs.

Frog Statistics. For example, in these statistics, while a POST requesting an image is as well. Note that this under-represents the bytes requested. Starting date for following statistics. The impact of fish and drought on frog breeding in temporary waters Correlation between chloride flux via the mitochondria-rich cells and transepithelial water movement in isolated frog skin Rana esculenta. Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells Frog eat frog : exploring variables influencing anurophagy.

Measey, G. John; Vimercati, Giovanni; de Villiers, F. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested.

We reviewed the literature on frog diet Molecular detection of vertebrates in stream water : a demonstration using Rocky Mountain tailed frogs and Idaho giant salamanders. Stream ecosystems harbor many secretive and imperiled species, and studies of vertebrates in these systems face the challenges of relatively low detection rates and high costs. Environmental DNA eDNA has recently been confirmed as a sensitive and efficient tool for documenting aquatic vertebrates in wetlands and in a large river and canal system.

However, it was unclear whether this tool could be used to detect low-density vertebrates in fast-moving streams where shed cells may travel rapidly away from their source. To evaluate the potential utility of eDNA techniques in stream systems, we designed targeted primers to amplify a short, species-specific DNA fragment for two secretive stream amphibian species in the northwestern region of the United States Rocky Mountain tailed frogs , Ascaphus montanus, and Idaho giant salamanders, Dicamptodon aterrimus.

We successfully amplified and sequenced the targeted DNA regions for both species from stream water filter samples. We detected Idaho giant salamanders in all samples and Rocky Mountain tailed frogs in four of five streams and found some indication that these species are more difficult to detect using eDNA in early spring than in early fall.

While the sensitivity of this method across taxa remains to be determined, the use of eDNA could revolutionize surveys for rare and invasive stream species. With this study, the utility of eDNA techniques for detecting aquatic vertebrates has been demonstrated across the majority of freshwater systems, setting the stage for an innovative transformation in approaches for aquatic research. Full Text Available Stream ecosystems harbor many secretive and imperiled species, and studies of vertebrates in these systems face the challenges of relatively low detection rates and high costs.

Water movements, tadpole competition and limits to the distribution of the frogs Ranidella riparia and R. Ranidella signifera and R. One hypothesisto explain the distributional limits is that each species cannot persist in the creeks beyond its range. Survival and growth of tadpoles were measured in enclosures in three creeks, one on either side of the overlap zone and one in it.

When each species was kept alone there were no differences between them either in the slow water typical of R. When the two species were kept together there were no consistent differences in survival or growth in any creek where water flow was shielded in the experimental enclosures.

Where water flow was not shielded through the enclosures R. A form of interaction is proposed where R. This may explain why R. Biospectroscopy reveals the effect of varying water quality on tadpole tissues of the common frog Rana temporaria. Amphibians are undergoing large population declines in many regions around the world.

As environmental pollution from both agricultural and urban sources has been implicated in such declines, there is a need for a biomonitoring approach to study potential impacts on this vulnerable class of organism. This study assessed the use of infrared IR spectroscopy as a tool to detect changes in several tissues liver, muscle, kidney, heart and skin of late-stage common frog Rana temporaria tadpoles collected from ponds with differing water quality.

Small differences in spectral signatures were revealed between a rural agricultural pond and an urban pond receiving wastewater and landfill run-off; these were limited to the liver and heart, although large differences in body size were apparent, surprisingly with tadpoles from the urban site larger than those from the rural site.

Large differences in liver spectra were found between tadpoles from the pesticide and nutrient impacted pond compared to the rural agricultural pond, particularly in regions associated with lipids. Liver mass and hepatosomatic indices were found to be significantly increased in tadpoles from the site impacted by pesticides and trace organic chemicals, suggestive of exposure to environmental contamination.

Significant alterations were also found in muscle tissue between tadpoles from these two ponds in regions associated with glycogen, potentially indicative of a stress response. This study highlights the use of IR spectroscopy, a low-cost, rapid and reagent-free technique in the biomonitoring of a class of organisms susceptible to environmental degradation.

All rights reserved. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis. Around one fifth of the records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual.

Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data. Large invasive frogs that live in forests with high anuran diversity are most likely to have a higher proportion of anurans in their diet.

We confirm the validity of the size hypothesis for anurophagy, but show that there are additional significant variables. The circumstances under which frogs eat frogs are likely to be complex, but our data may help to alert conservationists to the possible dangers of invading frogs entering areas with threatened anuran species.

Full Text Available Background. Water velocity tolerance in tadpoles of the foothill yellow-legged frog Rana boylii : Swimming performance, growth, and survival. We explored the effects of large magnitude flow fluctuations in rivers with dams, commonly referred to as pulsed flows, on tadpoles of the lotic-breeding Foothill Yellow-legged Frog , Rana boylii. We quantified the velocity conditions in habitats occupied by tadpoles and then conducted experiments to assess the tolerance to values at the upper limit This study assessed the use of infrared IR spectroscopy as a tool to detect changes in several tissues liver, muscle, kidney, heart and skin of late-stage common frog Rana temporaria tadpol White-nose syndrome pathology grading in Nearctic and Palearctic bats.

While white-nose syndrome WNS has decimated hibernating bat populations in the Nearctic, species from the Palearctic appear to cope better with the fungal skin infection causing WNS. This has encouraged multiple hypotheses on the mechanisms leading to differential survival of species exposed to the same pathogen.

To facilitate intercontinental comparisons, we proposed a novel pathogenesis-based grading scheme consistent with WNS diagnosis histopathology criteria. UV light-guided collection was used to obtain single biopsies from Nearctic and Palearctic bat wing membranes non-lethally. The proposed scheme scores eleven grades associated with WNS on histopathology.

Given weights reflective of grade severity, the sum of findings from an individual results in weighted cumulative WNS pathology score. The probability of finding fungal skin colonisation and single, multiple or confluent cupping erosions increased with increase in Pseudogymnoascus destructans load. Increasing fungal load mimicked progression of skin infection from epidermal surface colonisation to deep dermal invasion.

Similarly, the number of UV-fluorescent lesions increased with increasing weighted cumulative WNS pathology score, demonstrating congruence between WNS-associated tissue damage and extent of UV fluorescence. In a case report, we demonstrated that UV-fluorescence disappears within two weeks of euthermy. Change in fluorescence was coupled with a reduction in weighted cumulative WNS pathology score, whereby both methods lost diagnostic utility.

While weighted cumulative WNS pathology scores were greater in the Nearctic than Palearctic , values for Nearctic bats were within the range of those for Palearctic species. Accumulation of wing damage probably influences mortality in affected bats, as demonstrated by a fatal case of Myotis daubentonii with natural WNS infection and healing in Myotis myotis.

The proposed semi-quantitative pathology score provided good agreement between experienced. Full Text Available While white-nose syndrome WNS has decimated hibernating bat populations in the Nearctic, species from the Palearctic appear to cope better with the fungal skin infection causing WNS.

The proposed semi-quantitative pathology score provided good agreement. Courtship in Frogs. Debjani Roy. General Article Volume 1 Issue 12 December pp A preliminary phylogeny of the Palearctic naked-toed geckos Reptilia: Squamata: Gekkonidae with taxonomic implications. Indogekko is embedded within Cyrtopodion and is here treated as a subgenus. Peatlands and green frogs : A relationship regulated by acidity? The effects of site acidification on amphibian populations have been thoroughly addressed in the last decades.

However, amphibians in naturally acidic environments, such as peatlands facing pressure from the peat mining industry, have received little attention. Through two field studies and an experiment, I assessed the use of bog habitats by the green frog Rana clamitans melanota , a species sensitive to various forestry and peat mining disturbances. First, I compared the occurrence and breeding patterns of frogs in bog and upland ponds. I then evaluated frog movements between forest and bog habitats to determine whether they corresponded to breeding or postbreeding movements.

Finally, I investigated, through a field experiment, the value of bogs as rehydrating areas for amphibians by offering living Sphagnum moss and two media associated with uplands i. Green frog reproduction at bog ponds was a rare event, and no net movements occurred between forest and bog habitats.

However, acutely dehydrated frogs did not avoid Sphagnum. Results show that although green frogs rarely breed in bogs and do not move en masse between forest and bog habitats, they do not avoid bog substrates for rehydrating, despite their acidity. Thus, bogs offer viable summering habitat to amphibians, which highlights the value of these threatened environments in terrestrial amphibian ecology. Assessment of water pollution in the Brazilian Pampa biome by means of stress biomarkers in tadpoles of the leaf frog Phyllomedusa iheringii Anura: Hylidae.

Full Text Available The Brazilian Pampa biome is currently under constant threat due to increase of agriculture and improper management of urban effluents. Studies with a focus on the assessment of impacts caused by human activities in this biome are scarce. In the present study, we measured stress-related biomarkers in tadpoles of the leaf frog Phyllomedusa iheringii, an endemic species to the Pampa biome, and tested its suitability as a bioindicator for the assessment of potential aquatic contamination in selected ponds S1 and S2 nearby agricultural areas in comparison to a reference site.

A significant decrease in acetylcholinesterase activity was observed in S2 when compared to S1 and reference. The levels of total-hydroperoxides were increased in S2 site. In parallel, increased activity of the antioxidant enzymes catalase, superoxide dismutase and glutathione S-transferase were observed in S2 when compared to S1 and reference. Further studies are necessary in order to correlate the changes observed here with different chemical stressors in water , as well as to elucidate mechanisms of toxicity induced by pesticides in amphibian species endemic to the Pampa biome.

Nevertheless, our study validates Phyllomedusa iheringii as a valuable bioindicator in environmental studies. The Brazilian Pampa biome is currently under constant threat due to increase of agriculture and improper management of urban effluents. Where is the line? Phylogeography and secondary contact of western Palearctic coal tits Periparus ater: Aves, Passeriformes, Paridae.

Generally, between population differentiation was greatest in the Mediterranean range, which was explained by a greater Genetic diversity indices were lowest on Mediterranean island populations as compared to continental populations. At the same time, at least four distinct genetic lineages emerged in eastern Eurasia, the nominate ater subspecies group being one of them.

Finally, during the Holocene extant wide-range secondary contact in Europe was established via rapid westward range expansion from an East Asian refuge and via White-nose syndrome without borders: Pseudogymnoascus destructans infection tolerated in Europe and Palearctic Asia but not in North America.

A striking feature of white-nose syndrome, a fungal infection of hibernating bats, is the difference in infection outcome between North America and Europe. Palearctic bat communities tolerate similar fungal loads of Pseudogymnoascus destructans infection as their Nearctic counterparts and histopathology indicates equal focal skin tissue invasiveness pathognomonic for WNS lesions.

Fungal load positively correlates with disease intensity and it reaches highest values at intermediate latitudes. Prevalence and fungal load dynamics in Palearctic bats remained persistent and high between and Dominant haplotypes of five genes are widespread in North America, Europe and Asia, expanding the source region of white-nose syndrome to non-European hibernacula.

Our data provides evidence for both endemicity and tolerance to this persistent virulent fungus in the Palearctic , suggesting that host-pathogen interaction equilibrium has been established. Pt is the Photochemical characterization of water samples from Minnesota and Vermont sites with malformed frogs : potential influence of photosensitization by singlet molecular oxygen 1O2 and free radicals on aquatic toxicity.

Environmental pollutants activated by UV sunlight may have contributed to the recent decline in frog populations and the concomitant increase in malformations in the USA and abroad. UV radiation is able to mutate DNA and to initiate photosensitization processes that generate mutagenic and biologically disruptive oxygen transients. We have examined water from selected sites in Minnesota and Vermont using singlet molecular oxygen 1 O 2 , detected by its phosphorescence and free radicals detected by spin trapping, as markers for photosensitization.

Water from a pond in Minnesota with malformed frogs , which also causes malformations in the laboratory, photosensitized more 1 O 2 , even though it absorbed less UV light compared to water from a site that did not cause malformations. This suggested that unknown natural or pollutant agents were present, and that photosensitization may be involved. We also examined water samples from several sites in Vermont, and compared them by measuring the quantum yield of 1 O 2 photosensitization.

While all the Vermont samples produced a small amount of 1 O 2 , there was no clear correlation with the incidence of frog malformations. However, the samples differed strongly in absorption spectra and the ability to quench 1 O 2. These factors may determine how much UV light is absorbed and converted into chemical reactions. Our results show that photochemical characterization of 1 O 2 photosensitization is possible in untreated natural water samples.

Photosensitization falls into the category of global factors that may be closely associated with the effects of UV irradiation of the Earth's environments. Thus, photosensitization might be an important. Photosensitization falls into the category of global factors that may be closely associated with the effects of. Lithobates sylvaticus wood frog. A single specimen found southwest of Hattiesburg in Timberton Gary, Kat, and Ron Lukens.

This species has never been recorded from the state of Mississippi before Dodd Frogs of the United States and Canada — Volume 2. According to Dodd , the closest population is located in east central Alabama, approximately km to the northeast, as documented by Davis and Folkerts Brimleyana Molecular phylogenetics and historical biogeography of the west- palearctic common toads Bufo bufo species complex.

In most pan-Eurasiatic species complexes, two phenomena have been traditionally considered key processes of their cladogenesis and biogeography. First, it is hypothesized that the origin and development of the Central Asian Deserts generated a biogeographic barrier that fragmented past continuous distributions in Eastern and Western domains. Second, Pleistocene glaciations have been proposed as the main process driving the regional diversification within each of these domains.

The European common toad and its closest relatives provide an interesting opportunity to examine the relative contributions of these paleogeographic and paleoclimatic events to the phylogeny and biogeography of a widespread Eurasiatic group.

We investigate this issue by applying a multiproxy approach combining information from molecular phylogenies, a multiple correspondence analysis of allozyme data and species distribution models. Our study includes specimens from populations, covering most of the distributional range of the Bufo bufo species complex in the Western Palearctic. A dataset with species of the family Bufonidae was assembled to estimate the separation of the two pan-Eurasiatic species complexes of Bufo and to date the main biogeographic events within the Bufo bufo species complex.

The allozyme study included sixteen protein systems, corresponding to 21 presumptive loci. Finally, the distribution models were based on maximum entropy. Our distribution models show that Eastern and Western species complexes are greatly isolated by the Central Asian Deserts, and our dating estimates place this divergence during the Middle Miocene, a moment in which different sources of evidence document a major upturn of the aridification rate of Central Asia.

This climate-driven process likely separated the Eastern and Western species. At the. High levels of prevalence related to age and body condition: host-parasite interactions in a water frog Pelophylax kl hispanicus. Full Text Available Host traits can significantly influence patterns of infection and disease. Here, we studied the helminths parasitizing the Italian edible frog Pelophylax kl. The helminth community was composed of seven species: three trematode species Diplodiscus subclavatus, Gorgodera cygnoides, Pleurogenes claviger, three nematode species Icosiella neglecta, Oswaldocruzia filiformis, Rhabdias sp.

We found that prevalence was positively correlated with snout-vent length and weight, but did not differ with body condition or sex. We found that prevalence and mean species richness increased with age. Our results show that abundance of Icosiella neglecta was positively correlated with higher values for host body condition. In fact, we found that high prevalence and mean species richness do not necessarily imply poorer body condition in the parasitized host.

In conclusion, our results show that the helminth community in this taxon has great diversity, and this host-parasite system seems to be evolved to low levels of virulence, helminths maintaining a commensal relationship with this frog. Reconstructing community assembly in time and space reveals enemy escape in a Western Palearctic insect community.

How geographically widespread biological communities assemble remains a major question in ecology. Do parallel population histories allow sustained interactions such as host-parasite or plant-pollinator among species, or do discordant histories necessarily interrupt them? Though few empirical data exist, these issues are central to our understanding of multispecies evolutionary dynamics. Here we use hierarchical approximate Bayesian analysis of DNA sequence data for 12 herbivores and 19 parasitoids to reconstruct the assembly of an insect community spanning the Western Palearctic and assess the support for alternative host tracking and ecological sorting hypotheses.

We show that assembly occurred primarily by delayed host tracking from a shared eastern origin. Herbivores escaped their enemies for millennia before parasitoid pursuit restored initial associations, with generalist parasitoids no better able to track their hosts than specialists. In contrast, ecological sorting played only a minor role. Substantial turnover in host-parasitoid associations means that coevolution must have been diffuse, probably contributing to the parasitoid generalism seen in this and similar systems.

Reintegration of parasitoids after host escape shows these communities to have been unsaturated throughout their history, arguing against major roles for parasitoid niche evolution or competition during community assembly. S1 satellite DNA repetitive units display identical structure and overall variability in all Anatolian brown frog taxa. S1 satellite DNA from Palearctic brown frogs has a species-specific structure in all European species.

Moreover, quantitative dot blots showed that this satellite DNA accounts for 0. Analysis of the overall genomic variability of the S1a repeat sequence in specimens from various populations demonstrated that this repetitive unit also has the same size bp , the same most common sequence MCS and the same overall variability in all three taxa, and also in R.

The S1a repetitive unit presents three deletions of 9, 8 and 1 bp compared to the bp S1a repeat from European frogs. Unlike previously analyzed mitochondrial and nuclear sequences that show considerable variations among these taxa, no difference could be detected in the structure and variability of the S1 satellite repetitive units. This suggests that these taxa should belong to a single species. Our results indicate that this satellite DNA variety probably formed when the Anatolian lineage radiated from common ancestor about 4 mya, and since then has maintained its structure in all four taxa examined.

Effects of water temperature on breeding phenology, growth and timing of metamorphosis of foothill yellow-legged frogs Rana boylii on the mainstem and selected tributaries of California's Trinity River - The cold temperatures maintained in the Trinity River are beneficial to fish but may be problematic for foothill yellow-legged frogs. We examined the timing of breeding, reproductive output, and growth and development of tadpoles for populations of foothill yellow-legged frogs on the mainstem and six tributaries of the Trinity River.

On the colder mainstem, onset of Full Text Available For understanding the mechanism of frog swimming under water and designing a frog -inspired swimming robot, kinematics of the frog body and trajectories of joints should be obtained. In this paper, an aquatic frog , Xenopus laevis, was chosen for analysis of swimming motions which were recorded by a high speed camera, and kinematic data were processed in a swimming data extraction platform.

According to the shape features of the frog , we propose a method that the frog eyes are set as the natural data extraction markers for body motion, and kinematic data of joint trajectories are calculated by the contour points on the limbs. For the data processing, a pinhole camera model was built to transform the pixel coordinate system to world coordinate system, and the errors caused by the water refraction were analyzed and corrected.

Finally, from the developed data extraction platform, the kinematic data for the analysis of swimming mechanism and design of frog -inspired robot were obtained. Multiple origins of elytral reticulation modifications in the west palearctic Agabus bipustulatus complex coleoptera, dytiscidae. Full Text Available The Agabus bipustulatus complex includes one of Europe's most widely distributed and common diving beetles.

This complex, which is known for its large morphological variation, has a complex demographic and altitudinal variation in elytral reticulation. The various depth of the reticulation imprint, both in smaller and larger meshes, results in both mat and shiny individuals, as well as intermediate forms. The West Palearctic lowland is inhabited by a sexually dimorphic form, with shiny males and mat females.

In mountain regions, shiny individuals of both sexes are found intermixed with mat individuals or in pure populations in central and southern areas, whereas pure populations of mat individuals are exclusively found in the northern region at high altitude.

Sexual selection is proposed as a driving force in shaping this variation. However, the occurrence of different types of reticulation in both sexes and disjunct geographical distribution patterns suggest an additional function of the reticulation. Here we investigate the phylogeographical history, genetic structure and reticulation variation of several named forms within the Agabus bipustulatus complex including A.

The molecular analyses recognised several well-supported clades within the complex. Several of the named forms had two or more independent origins. Few south European populations were uniform in reticulation patterns, and the males were found to display large variation. Reticulation diversity and population genetic variability were clearly correlated to altitude, but no genetic differences were detected among populations with mixed or homogenous forms.

Observed reduction in secondary reticulation in female and increased variance in male at high altitude in South Europe may be explained by the occurrence of an additional selective force, beside sexual selection. The combined effect of these selective processes is here demonstrated in an extreme case to generate. The Agabus bipustulatus complex includes one of Europe's most widely distributed and common diving beetles.

The combined effect of these selective processes is here demonstrated in an extreme case to generate isolation barriers between. Pemanfaatan kulit kodok bull frog. Full Text Available The objective of this study was to measure the tensile strength and the elongation of finished leather made from Bull Frog skin, so that the utilization of that leather can be specified. The samples used were twenty pieces of wet salted Bull Frog skin from East Java which have been processed to finished leather using chromosal B.

Based on those results, it can be concluded that Bull Frog leather was suitable for leather goods such as bag, wallet, etc. Autometallographic tracing of mercury in frog liver. The distribution of mercury in the liver of the frog Rana ridibunda with the autometallographic method was investigated.

Thus, only a fraction of the Hg can be visualized. Six animals were exposed for one day and another group of six animals for 6 days in 1 ppm mercury as HgCI 2 dissolved in fresh water. A third group of six animals, served as controls, were sacrificed the day of arrival at the laboratory. First, mercury appears in the blood plasma and erythrocytes. Next, mercury moves to hepatocytes and in the apical part of the cells, that facing bile canaliculi.

In a next step, mercury appears in the endothelial and Kupffer cells. Most probably, the endothelial and Kupffer cells comprise the first line of defense against metal toxicity. Guinea Worm in a Frog. Mark Eberhard, a retired parasitologist and CDC guest researcher, discusses Guinea worm infection in a wild-caught frog.

Geographic morphological variation in parapatric Western Palearctic tree frogs , Hyla arborea and Hyla savignyi: are related species similarly affected by climatic conditions? Natural disturbance reduces disease risk in endangered rainforest frog populations. Natural disturbances can drive disease dynamics in animal populations by altering the microclimates experienced by hosts and their pathogens. Many pathogens are highly sensitive to temperature and moisture, and therefore small changes in habitat structure can alter the microclimate in ways that increase or decrease infection prevalence and intensity in host populations.

Here we show that a reduction of rainforest canopy cover caused by a severe tropical cyclone decreased the risk of endangered rainforest frogs Litoria rheocola becoming infected by a fungal pathogen Batrachochytrium dendrobatidis.

Reductions in canopy cover increased the temperatures and rates of evaporative water loss in frog microhabitats, which reduced B. Natural disturbances to the rainforest canopy can therefore provide an immediate benefit to frogs by altering the microclimate in ways that reduce infection risk.

This could increase host survival and reduce the probability of epidemic disease outbreaks. For amphibian populations under immediate threat from this pathogen, targeted manipulation of canopy cover could increase the availability of warmer, drier microclimates and therefore tip the balance from host extinction to coexistence.

They exhibit non-Keplerian motion Tiscareno et al. Pan and Chiang proposed that propeller moonlets librate in ' frog resonances' with co-orbiting ring material. By analogy with the restricted three-body problem, they treated the co-orbital material as stationary in the rotating frame and neglected non-co-orbital material.

Here we use simple numerical experiments to extend the frog model, including feedback due to the gap's motion, and drag associated with the Lindblad disk torques that cause Type I migration. Because the moonlet creates the gap, we expect the gap centroid to track the moonlet, but only after a time delay t delay , the time for a ring particle to travel from conjunction with the moonlet to the end of the gap.

We find that frog librations can persist only if t delay exceeds the frog libration period P lib , and if damping from Lindblad torques balances driving from co-orbital torques. If t delay ib , then the libration amplitude damps to zero. We urge more accurate treatments of feedback to test the assumptions of our toy models. Raptor habitat use in the Lake Chad Basin : Insights into the effect of flood-plain transformation on Afrotropical and Palearctic raptors. West African flood-plains have undergone major land-use transformations in the second half of the 20th century.

To obtain insight in the effect of flood-plain development for irrigated rice cultivation on the abundance, richness, and diversity of Palearctic and Afrotropical raptors, we conducted. From frog integument to human skin: dermatological perspectives from frog skin biology. Haslam, I. For over a century, frogs have been studied across various scientific fields, including physiology, embryology, neuroscience, neuro endocrinology, ecology, genetics, behavioural science, evolution, drug development, and conservation biology.

In some cases, frog skin has proven very successful as a. Effects of the herbicide imazapyr on juvenile Oregon spotted frogs. Conflict between native amphibians and aquatic weed management in the Pacific Northwest is rarely recognized because most native stillwater-breeding amphibian species move upland during summer, when herbicide application to control weeds in aquatic habitats typically occurs.

However, aquatic weed management may pose a risk for aquatic species present in wetlands through the summer, such as the Oregon spotted frog OSF, Rana pretiosa , a state endangered species in Washington. Acute toxicity of herbicides used to control aquatic weeds tends to be low, but the direct effects of herbicide tank mixes on OSFs have remained unexamined.

We exposed juvenile OSFs to tank mixes of the herbicide imazapyr, a surfactant, and a marker dye in a h static-renewal test. The tank mix was chosen because of its low toxicity to fish and its effectiveness in aquatic weed control. Concentrations were those associated with low-volume 3. Following exposure, frogs were reared for two months in clean water to identify potential latent effects on growth.

Endpoints evaluated included feeding behavior, growth, and body and liver condition indices. We recorded no mortalities and found no significant differences for any end point between the herbicide-exposed and clean- water control frogs. The results suggest that imazapyr use in wetland restoration poses a low risk of direct toxic effects on juvenile OSFs. Snoring puddle frog. Full text: The purpose of this paper is to hold a biological mirror in front of ourselves, the nuclear energy community, and to suggest that the reflection we will see there will help us both professionally and as members of a broader society.

Let us start with sex. For sex to function as a means of reproduction, a male and a female of a particular species have to recognise each other and mate. The important terms here are 'particular species' and 'recognise'. Within most species, extraordinarily precise mate recognition systems have evolved. The precise frequency of the croak of a particular species of frog ; the precise seasonal coloration of a particular species of salmon; the precise length of the tail of a particular species of bird; each is recognisable instantly to a prospective mate, though not to untrained human ears or eyes.

Its author, HEH Paterson, suggests that a species can be defined as a group of organisms that share a common mate recognition system. Mating is an exchange of genes, and creatures that do not recognise each other do not exchange genes. A mate recognition system closes off the gene pool and may increasingly isolate its participants from even their nearest relatives.

Biological evolution has numerous links and parallels with the evolution of human cultures. Some of our recognition systems seem to have a knack for drawing everyone in - American popular culture, for example, is now inescapable. Other recognition systems repel all but a few - take, or rather don't take, the Hell's Angels or the Ku Klux Klan.

We, as members of the nuclear energy culture, are members of a closed and even repellent gene pool. We share a recognition system by which we perpetuate ourselves from generation to generation, from Hiroshima to Chernobyl. Outsiders do not understand our language: terms like 'credit for fission products. Effects of acute exposure to magnetic field on ionic composition of frog sciatic nerve.

Objective: To evaluate the possible interaction between magnetic field and cadmium on ionic composition of frog sciatic nerve. Design: The combined effect of magnetic field and cadmium 1. Sciatic nerve samples were extracted, weighed and mixed in bidistilled water in order to analyze by inductively coupled plasma ICP ionic composition.

Magnetic field magnifies the effect of cadmium on calcium homeostasis. Full Text Available Background: There has been increasing awareness throughout the world regarding the remarkable decrease in amphibian population. For such amphibian population decline several causes have been given.

Cadmium, a heavy metal is released both from natural sources leaching of cadmium rich soils and anthropogenic activities to the aquatic and terrestrial environments. This study evaluated the toxicity of heavy metal cadmium to Indian skipper frog Rana cyanophlyctis.

Methods: For the determination of LC50 values for cadmium, four-day static renewal acute toxicity test was used. Results: The LC50 values of cadmium chloride for the frog R. The results have been discussed with the toxicity reported for other aquatic vertebrate --fish.

Conclusion: Cadmium caused mortality to the frog and this could be one of the reasons for population decline of frogs which inhabit water contaminated with heavy metals. Effect of cattle exclosures on Columbia Spotted Frog abundance. Adams, Michael J. Livestock grazing is an important land use in the western USA and can have positive or negative effects on amphibians.

Columbia Spotted Frog Rana luteiventris often use ponds that provide water for cattle. We conducted a long-term manipulative study on US Forest Service land in northeastern Oregon to determine the effects of full and partial exclosures that limited cattle access to ponds used by frogs. We found weak evidence of a short-term increase in abundance that did not differ between full and partial exclosures and that diminished with continuing exclusion of cattle.

The benefit of exclosures was small relative to the overall decline in breeding numbers that we documented. This suggests that some protection can provide a short-term boost to populations. Pesticide concentrations in frog tissue and wetland habitats in a landscape dominated by agriculture.

Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations.

We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata chorus frogs and Lithobates pipiens leopard frogs at six wetlands 3 restored and 3 reference in Iowa, USA.

Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs.

Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs , possibly because of differences in life histories.

Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and implementing. Pesticide concentrations in frog tissue and wetland habitats in alandscape dominated by agriculture. Smalling, Kelly L.

Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and. Oregon spotted frogs breed in shallow pools in cm deep that are near flowing water , or Friesz , p. They are laid in shallow, often temporary, pools of water ; gradually receding Eleutherodactylus frog introductions to Hawaii.

As an oceanic archipelago isolated from continental source areas, Hawaii lacks native terrestrial reptiles and amphibians, Polynesians apparently introduced seven gecko and skink species after discovering the islands approximately years ago, and another 15 reptiles and five frogs have been introduced in the last century and a half McKeown The Polynesian introductions are probably inadvertent because the species involved are known stowaway dispersers Gibbons ; Dye and Steadman , In contrast, most of the herpetological introductions since European contact with Hawaii have been intentional.

Several frog species were released for biocontrol of insects e. Neuromuscular control of prey capture in frogs. While retaining a feeding apparatus that is surprisingly conservative morphologically, frogs as a group exhibit great variability in the biomechanics of tongue protraction during prey capture, which in turn is related to differences in neuromuscular control.

SEFOREX LEVALLOIS PERRET CEDEX

Here we use hierarchical approximate Bayesian analysis of DNA sequence data for 12 herbivores and 19 parasitoids to reconstruct the assembly of an insect community spanning the Western Palearctic and assess the support for alternative host tracking and ecological sorting hypotheses. We show that assembly occurred primarily by delayed host tracking from a shared eastern origin. Herbivores escaped their enemies for millennia before parasitoid pursuit restored initial associations, with generalist parasitoids no better able to track their hosts than specialists.

In contrast, ecological sorting played only a minor role. Substantial turnover in host-parasitoid associations means that coevolution must have been diffuse, probably contributing to the parasitoid generalism seen in this and similar systems. Reintegration of parasitoids after host escape shows these communities to have been unsaturated throughout their history, arguing against major roles for parasitoid niche evolution or competition during community assembly.

S1 satellite DNA repetitive units display identical structure and overall variability in all Anatolian brown frog taxa. S1 satellite DNA from Palearctic brown frogs has a species-specific structure in all European species. Moreover, quantitative dot blots showed that this satellite DNA accounts for 0. Analysis of the overall genomic variability of the S1a repeat sequence in specimens from various populations demonstrated that this repetitive unit also has the same size bp , the same most common sequence MCS and the same overall variability in all three taxa, and also in R.

The S1a repetitive unit presents three deletions of 9, 8 and 1 bp compared to the bp S1a repeat from European frogs. Unlike previously analyzed mitochondrial and nuclear sequences that show considerable variations among these taxa, no difference could be detected in the structure and variability of the S1 satellite repetitive units. This suggests that these taxa should belong to a single species. Our results indicate that this satellite DNA variety probably formed when the Anatolian lineage radiated from common ancestor about 4 mya, and since then has maintained its structure in all four taxa examined.

Effects of water temperature on breeding phenology, growth and timing of metamorphosis of foothill yellow-legged frogs Rana boylii on the mainstem and selected tributaries of California's Trinity River - The cold temperatures maintained in the Trinity River are beneficial to fish but may be problematic for foothill yellow-legged frogs.

We examined the timing of breeding, reproductive output, and growth and development of tadpoles for populations of foothill yellow-legged frogs on the mainstem and six tributaries of the Trinity River. On the colder mainstem, onset of Full Text Available For understanding the mechanism of frog swimming under water and designing a frog -inspired swimming robot, kinematics of the frog body and trajectories of joints should be obtained.

In this paper, an aquatic frog , Xenopus laevis, was chosen for analysis of swimming motions which were recorded by a high speed camera, and kinematic data were processed in a swimming data extraction platform. According to the shape features of the frog , we propose a method that the frog eyes are set as the natural data extraction markers for body motion, and kinematic data of joint trajectories are calculated by the contour points on the limbs.

For the data processing, a pinhole camera model was built to transform the pixel coordinate system to world coordinate system, and the errors caused by the water refraction were analyzed and corrected. Finally, from the developed data extraction platform, the kinematic data for the analysis of swimming mechanism and design of frog -inspired robot were obtained.

Multiple origins of elytral reticulation modifications in the west palearctic Agabus bipustulatus complex coleoptera, dytiscidae. Full Text Available The Agabus bipustulatus complex includes one of Europe's most widely distributed and common diving beetles.

This complex, which is known for its large morphological variation, has a complex demographic and altitudinal variation in elytral reticulation. The various depth of the reticulation imprint, both in smaller and larger meshes, results in both mat and shiny individuals, as well as intermediate forms. The West Palearctic lowland is inhabited by a sexually dimorphic form, with shiny males and mat females.

In mountain regions, shiny individuals of both sexes are found intermixed with mat individuals or in pure populations in central and southern areas, whereas pure populations of mat individuals are exclusively found in the northern region at high altitude.

Sexual selection is proposed as a driving force in shaping this variation. However, the occurrence of different types of reticulation in both sexes and disjunct geographical distribution patterns suggest an additional function of the reticulation. Here we investigate the phylogeographical history, genetic structure and reticulation variation of several named forms within the Agabus bipustulatus complex including A.

The molecular analyses recognised several well-supported clades within the complex. Several of the named forms had two or more independent origins. Few south European populations were uniform in reticulation patterns, and the males were found to display large variation. Reticulation diversity and population genetic variability were clearly correlated to altitude, but no genetic differences were detected among populations with mixed or homogenous forms.

Observed reduction in secondary reticulation in female and increased variance in male at high altitude in South Europe may be explained by the occurrence of an additional selective force, beside sexual selection. The combined effect of these selective processes is here demonstrated in an extreme case to generate. The Agabus bipustulatus complex includes one of Europe's most widely distributed and common diving beetles.

The combined effect of these selective processes is here demonstrated in an extreme case to generate isolation barriers between. Pemanfaatan kulit kodok bull frog. Full Text Available The objective of this study was to measure the tensile strength and the elongation of finished leather made from Bull Frog skin, so that the utilization of that leather can be specified. The samples used were twenty pieces of wet salted Bull Frog skin from East Java which have been processed to finished leather using chromosal B.

Based on those results, it can be concluded that Bull Frog leather was suitable for leather goods such as bag, wallet, etc. Autometallographic tracing of mercury in frog liver. The distribution of mercury in the liver of the frog Rana ridibunda with the autometallographic method was investigated.

Thus, only a fraction of the Hg can be visualized. Six animals were exposed for one day and another group of six animals for 6 days in 1 ppm mercury as HgCI 2 dissolved in fresh water. A third group of six animals, served as controls, were sacrificed the day of arrival at the laboratory. First, mercury appears in the blood plasma and erythrocytes. Next, mercury moves to hepatocytes and in the apical part of the cells, that facing bile canaliculi.

In a next step, mercury appears in the endothelial and Kupffer cells. Most probably, the endothelial and Kupffer cells comprise the first line of defense against metal toxicity. Guinea Worm in a Frog. Mark Eberhard, a retired parasitologist and CDC guest researcher, discusses Guinea worm infection in a wild-caught frog. Geographic morphological variation in parapatric Western Palearctic tree frogs , Hyla arborea and Hyla savignyi: are related species similarly affected by climatic conditions?

Natural disturbance reduces disease risk in endangered rainforest frog populations. Natural disturbances can drive disease dynamics in animal populations by altering the microclimates experienced by hosts and their pathogens. Many pathogens are highly sensitive to temperature and moisture, and therefore small changes in habitat structure can alter the microclimate in ways that increase or decrease infection prevalence and intensity in host populations.

Here we show that a reduction of rainforest canopy cover caused by a severe tropical cyclone decreased the risk of endangered rainforest frogs Litoria rheocola becoming infected by a fungal pathogen Batrachochytrium dendrobatidis. Reductions in canopy cover increased the temperatures and rates of evaporative water loss in frog microhabitats, which reduced B.

Natural disturbances to the rainforest canopy can therefore provide an immediate benefit to frogs by altering the microclimate in ways that reduce infection risk. This could increase host survival and reduce the probability of epidemic disease outbreaks. For amphibian populations under immediate threat from this pathogen, targeted manipulation of canopy cover could increase the availability of warmer, drier microclimates and therefore tip the balance from host extinction to coexistence.

They exhibit non-Keplerian motion Tiscareno et al. Pan and Chiang proposed that propeller moonlets librate in ' frog resonances' with co-orbiting ring material. By analogy with the restricted three-body problem, they treated the co-orbital material as stationary in the rotating frame and neglected non-co-orbital material. Here we use simple numerical experiments to extend the frog model, including feedback due to the gap's motion, and drag associated with the Lindblad disk torques that cause Type I migration.

Because the moonlet creates the gap, we expect the gap centroid to track the moonlet, but only after a time delay t delay , the time for a ring particle to travel from conjunction with the moonlet to the end of the gap. We find that frog librations can persist only if t delay exceeds the frog libration period P lib , and if damping from Lindblad torques balances driving from co-orbital torques.

If t delay ib , then the libration amplitude damps to zero. We urge more accurate treatments of feedback to test the assumptions of our toy models. Raptor habitat use in the Lake Chad Basin : Insights into the effect of flood-plain transformation on Afrotropical and Palearctic raptors. West African flood-plains have undergone major land-use transformations in the second half of the 20th century. To obtain insight in the effect of flood-plain development for irrigated rice cultivation on the abundance, richness, and diversity of Palearctic and Afrotropical raptors, we conducted.

From frog integument to human skin: dermatological perspectives from frog skin biology. Haslam, I. For over a century, frogs have been studied across various scientific fields, including physiology, embryology, neuroscience, neuro endocrinology, ecology, genetics, behavioural science, evolution, drug development, and conservation biology. In some cases, frog skin has proven very successful as a.

Effects of the herbicide imazapyr on juvenile Oregon spotted frogs. Conflict between native amphibians and aquatic weed management in the Pacific Northwest is rarely recognized because most native stillwater-breeding amphibian species move upland during summer, when herbicide application to control weeds in aquatic habitats typically occurs. However, aquatic weed management may pose a risk for aquatic species present in wetlands through the summer, such as the Oregon spotted frog OSF, Rana pretiosa , a state endangered species in Washington.

Acute toxicity of herbicides used to control aquatic weeds tends to be low, but the direct effects of herbicide tank mixes on OSFs have remained unexamined. We exposed juvenile OSFs to tank mixes of the herbicide imazapyr, a surfactant, and a marker dye in a h static-renewal test. The tank mix was chosen because of its low toxicity to fish and its effectiveness in aquatic weed control.

Concentrations were those associated with low-volume 3. Following exposure, frogs were reared for two months in clean water to identify potential latent effects on growth. Endpoints evaluated included feeding behavior, growth, and body and liver condition indices. We recorded no mortalities and found no significant differences for any end point between the herbicide-exposed and clean- water control frogs.

The results suggest that imazapyr use in wetland restoration poses a low risk of direct toxic effects on juvenile OSFs. Snoring puddle frog. Full text: The purpose of this paper is to hold a biological mirror in front of ourselves, the nuclear energy community, and to suggest that the reflection we will see there will help us both professionally and as members of a broader society.

Let us start with sex. For sex to function as a means of reproduction, a male and a female of a particular species have to recognise each other and mate. The important terms here are 'particular species' and 'recognise'. Within most species, extraordinarily precise mate recognition systems have evolved.

The precise frequency of the croak of a particular species of frog ; the precise seasonal coloration of a particular species of salmon; the precise length of the tail of a particular species of bird; each is recognisable instantly to a prospective mate, though not to untrained human ears or eyes. Its author, HEH Paterson, suggests that a species can be defined as a group of organisms that share a common mate recognition system.

Mating is an exchange of genes, and creatures that do not recognise each other do not exchange genes. A mate recognition system closes off the gene pool and may increasingly isolate its participants from even their nearest relatives. Biological evolution has numerous links and parallels with the evolution of human cultures.

Some of our recognition systems seem to have a knack for drawing everyone in - American popular culture, for example, is now inescapable. Other recognition systems repel all but a few - take, or rather don't take, the Hell's Angels or the Ku Klux Klan. We, as members of the nuclear energy culture, are members of a closed and even repellent gene pool. We share a recognition system by which we perpetuate ourselves from generation to generation, from Hiroshima to Chernobyl.

Outsiders do not understand our language: terms like 'credit for fission products. Effects of acute exposure to magnetic field on ionic composition of frog sciatic nerve. Objective: To evaluate the possible interaction between magnetic field and cadmium on ionic composition of frog sciatic nerve.

Design: The combined effect of magnetic field and cadmium 1. Sciatic nerve samples were extracted, weighed and mixed in bidistilled water in order to analyze by inductively coupled plasma ICP ionic composition. Magnetic field magnifies the effect of cadmium on calcium homeostasis. Full Text Available Background: There has been increasing awareness throughout the world regarding the remarkable decrease in amphibian population.

For such amphibian population decline several causes have been given. Cadmium, a heavy metal is released both from natural sources leaching of cadmium rich soils and anthropogenic activities to the aquatic and terrestrial environments. This study evaluated the toxicity of heavy metal cadmium to Indian skipper frog Rana cyanophlyctis.

Methods: For the determination of LC50 values for cadmium, four-day static renewal acute toxicity test was used. Results: The LC50 values of cadmium chloride for the frog R. The results have been discussed with the toxicity reported for other aquatic vertebrate --fish.

Conclusion: Cadmium caused mortality to the frog and this could be one of the reasons for population decline of frogs which inhabit water contaminated with heavy metals. Effect of cattle exclosures on Columbia Spotted Frog abundance. Adams, Michael J. Livestock grazing is an important land use in the western USA and can have positive or negative effects on amphibians.

Columbia Spotted Frog Rana luteiventris often use ponds that provide water for cattle. We conducted a long-term manipulative study on US Forest Service land in northeastern Oregon to determine the effects of full and partial exclosures that limited cattle access to ponds used by frogs.

We found weak evidence of a short-term increase in abundance that did not differ between full and partial exclosures and that diminished with continuing exclusion of cattle. The benefit of exclosures was small relative to the overall decline in breeding numbers that we documented. This suggests that some protection can provide a short-term boost to populations.

Pesticide concentrations in frog tissue and wetland habitats in a landscape dominated by agriculture. Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations.

We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata chorus frogs and Lithobates pipiens leopard frogs at six wetlands 3 restored and 3 reference in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources.

Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations.

Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs , possibly because of differences in life histories.

Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and implementing. Pesticide concentrations in frog tissue and wetland habitats in alandscape dominated by agriculture.

Smalling, Kelly L. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and. Oregon spotted frogs breed in shallow pools in cm deep that are near flowing water , or Friesz , p. They are laid in shallow, often temporary, pools of water ; gradually receding Eleutherodactylus frog introductions to Hawaii. As an oceanic archipelago isolated from continental source areas, Hawaii lacks native terrestrial reptiles and amphibians, Polynesians apparently introduced seven gecko and skink species after discovering the islands approximately years ago, and another 15 reptiles and five frogs have been introduced in the last century and a half McKeown The Polynesian introductions are probably inadvertent because the species involved are known stowaway dispersers Gibbons ; Dye and Steadman , In contrast, most of the herpetological introductions since European contact with Hawaii have been intentional.

Several frog species were released for biocontrol of insects e. Neuromuscular control of prey capture in frogs. While retaining a feeding apparatus that is surprisingly conservative morphologically, frogs as a group exhibit great variability in the biomechanics of tongue protraction during prey capture, which in turn is related to differences in neuromuscular control. In this paper, I address the following three questions.

Prey specialization and diet of frogs in Borneo. Earlier studies of the diet of frogs indicate that most adult frogs are mainly insectivorous. Overall, frogs are viewed more as generalists than specialists in terms of their diet. However, despite earlier studies, there are still gaps in our knowledge regarding what frogs tend to eat and the degree of specialization.

The aim of this study was to investigate the diet choice of frogs in a tropical ecosystem. The present study was conducted in a well-known hotspot for frogs with 66 of the k Full Text Available Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy.

Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of various sizes to identify relationships between water and temperature buffering. Ferns are the preferred diurnal microhabitat and breeding habitat for arboreal frogs.

A strong positive relationship exists between fern size and frog usage and abundance. Our drying experiments show that large ferns buffer maximum temperatures and reduce variability in temperatures, and buffering is directly linked to their hydration. Frogs are likely using large ferns for their moist, cool, environments for breeding and daytime retreat, which supports the buffered microhabitat hypothesis—these plants promote species coexistence through habitat creation and amelioration of physical stress.

However, drying experiments suggest that this buffering is contingent on regular rainfall. Altered rainfall regimes could lead to the unexpected loss of the functional capacity of these important fern habitats. The Lake Titicaca frog Telmatobius culeus is critically endangered, primarily from overexploitation. However, additional threats, such as chytrid fungus Batrachochytrium dendrobatidis , are poorly studied.

We found moderate levels of chytrid infection using quantitative PCR. Our results enhance our understanding of chytrid tolerance to high pH and low water temperature. Migration through the Eastern Palearctic EP flyway by tundra swans Cygnus columbianus has not been thoroughly documented. We satellite-tracked the migration of 16 tundra swans that winter in Japan. The objectives of this study were 1 to show the migration pattern of the EP flyway of tundra swans; 2 to compare this pattern with the migration pattern of whooper swans; and 3 to identify stopover sites that are important for these swans' conservation.

Tundra swans were captured at Kutcharo Lake, Hokkaido, in and satellite-tracked. Based on median, the spring migration began on 18 April and ended on 27 May. Autumn migration began on 9 September and ended on 2 November. The median duration of the spring and autumn migrations were 48 and 50 days, respectively. The mean duration at one stopover site was 5. The number of stopover sites was 3. The mean travel distances for the spring and autumn migrations were and km, respectively.

There were 15, 32, and eight wintering, stopover, and breeding sites, respectively. The migration routes and staging areas of tundra swans partially overlap with those of whooper swans, whose migration patterns have been previously documented. Pesticides are receiving increasing attention as potential causes of amphibian declines, acting singly or in combination with other stressors, but limited information is available on the accumulation of current-use pesticides in tissue.

The authors examined potential exposure and accumulation of currently used pesticides in pond-breeding frogs Pseudacris regilla collected from 7 high elevations sites in northern California. Whole frog tissue, water , and sediment were analyzed for more than 90 current-use pesticides and pesticide degradates using gas chromatography—mass spectrometry.

Two fungicides, pyraclostrobin and tebuconazole, and one herbicide, simazine, were the most frequently detected pesticides in tissue samples. Tebuconazole and pyraclostrobin were the only 2 compounds observed frequently in frog tissue and sediment. Significant spatial differences in tissue concentration were observed, which corresponded to pesticide use in the upwind counties. Data generated indicated that amphibians residing in remote locations are exposed to and capable of accumulating current-use pesticides.

A comparison of P. We describe a new type of co-orbital resonance that can explain the observed non-Keplerian motions of propellers. The resonance is between the moonlet underlying the propeller and co-orbiting ring particles downstream of the moonlet where the gap closes. The moonlet librates within the gap about an equilibrium point established by co-orbiting material and stabilized by the Coriolis force. In the limit of small libration amplitude, the libration period scales linearly with the gap azimuthal width and inversely as the square root of the co-orbital mass.

The new resonance recalls but is distinct from conventional horseshoe and tadpole orbits; we call it the ' frog ' resonance, after the relevant term in equine hoof anatomy. These librations should be subtracted from the longitude data before any inferences about moonlet migration are made.

Regulation of 5'-adenosine monophosphate deaminase in the freeze tolerant wood frog , Rana sylvatica. Frozen frogs exhibit no vital signs and their organs must endure multiple stresses, particularly long term anoxia and ischemia. Maintenance of cellular energy supply is critical to viability in the frozen state and in skeletal muscle, AMP deaminase AMPD plays a key role in stabilizing cellular energetics.

The present study investigated AMPD control in wood frog muscle. Wood frog AMPD was subject to multiple regulatory controls: binding to subcellular structures, protein phosphorylation, and effects of allosteric effectors, cryoprotectants and temperature.

AMPD was a target of protein phosphorylation. ATP and Mg. ADP and inhibited by Mg. The enzyme product, IMP, uniquely inhibited only the bound phosphorylated enzyme from muscle of frozen frogs. Activators and inhibitors differentially affected the free versus bound enzyme.

Birds and frogs in mathematics and physics. Some scientists are birds, others are frogs. Birds fly high in the air and survey broad vistas of mathematics out to the far horizon. They delight in concepts that unify our thinking and bring together diverse problems from different parts of the landscape.

Frogs live in the mud below and see only the flowers that grow nearby. They delight in the details of particular objects, and they solve problems one at a time. A brief history of mathematics and its applications in physics is presented in this article. Hematophagous insects as vectors for frog trypanosomes. Experimental infections of three hematophagous arthropods Rhodnius prolixus, Aedes aegypti, and Culex pipiens with a trypanosome of the Trypanosoma rotatorium complex found in the frogs Hyla crepitans and Leptodactylus insularum revealed that A.

It is postulated that, in addition to the transmission of T. Differential uptake of gold nanoparticles by 2 species of tadpole, the wood frog Lithobates sylvaticus and the bullfrog Lithobates catesbeianus. Engineered nanoparticles are aquatic contaminants of emerging concern that exert ecotoxicological effects on a wide variety of organisms. Wood frog tadpoles alone and in combination with bullfrog tadpoles took up significantly more gold than bullfrogs. Bullfrog tadpoles in combination with wood frogs took up significantly more gold than controls.

In all gold-exposed groups of tadpoles, gold was concentrated in the anterior region compared with the posterior region of the body. The concentration of gold nanoparticles in the anterior region of wood frogs both alone and in combination with bullfrogs was significantly higher than the corresponding posterior regions. We also measured depuration time of gold in wood frogs. Our finding of differential uptake between closely related species living in similar habitats with overlapping geographical distributions argues against generalizing toxicological effects of nanoparticles for a large group of organisms based on measurements in only one species.

Environ Toxicol Chem ; Pseudacris triseriata western chorus frog and Rana sylvatica wood frog chytridiomycosis. The chytrid fungus Batrachochytrium dendrobatidis is a known pathogen of anuran amphibians, and has been correlated with amphibian die-offs worldwide Daszak et. Emerging Infectious Diseases In Colorado, B. We report the first verified case of chytrid fungus in chorus frogs Pseudacris triseriata and wood frogs Rana sylvatica in the United States.

We collected seven P. Chorus frogs were shipped in one container. Wood frog adults and juveniles were shipped in two separate containers. Histological examinations of all chorus frogs and 3 of 4 wood frogs were positive for chytrid fungus infection. The fourth adult wood frog was too decomposed for meaningful histology. Histological findings consisted of multifocally mild to diffusely severe infections of the epidermis of the ventrum and hindlimb digital skin.

Chytrid thalli were confined to the thickened epidermis hyperkeratosis , were spherical to oval, and occasional thalli contained characteristic discharge pores or zoospores Green and Kagarise Sherman Herpetol ; Fellers et al. Copeia We cannot confirm that all specimens carried the fungus at collection, because infection may have spread from one individual to all other individuals in each container during transport. Further sampling of amphibians in Kawuneeche Valley is warranted to determine the rate of infection and mortality in these populations.

Evolutionary dynamics across discontinuous freshwater systems: Rapid expansions and repeated allopolyploid origins in the Palearctic white water -lilies Nymphaea. Postglacial climate changes and rise of three ecotypes of harbour porpoises, Phocoena phocoena, in western Palearctic waters. Despite no obvious barriers to gene flow in the marine realm, environmental variation and ecological specializations can lead to genetic differentiation in highly mobile predators.

Here, we investigated the genetic structure of the harbour porpoise over the entire species distribution range in. Of volcanoes, saints, trash, and frogs. During one year of ethnographic fieldwork volcanoes, saints, trash and frogs were among the nonhuman entities referred to in conversations and engaged with when responding to the changes that trouble the world and everyday life of Arequipans A common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species.

For Columbia spotted frogs Rana luteiventris in the Great Basin USA , a genetically distinct population segment of conservation concern, we approached this problem by examining 1 landscape-scale habitat availability and distribution, 2 water body-scale habitat associations, and 3 resource management-identified threats to persistence.

We found that areas with perennial aquatic habitat and suitable climate are extremely limited in the southern portion of the species' range. Within these suitable areas, native and non-native predators trout and American bullfrogs [Lithobates catesbeianus] are widespread and may further limit habitat availability in upper- and lower-elevation areas, respectively. At the water body scale, spotted frog occupancy was associated with deeper sites containing abundant emergent vegetation and nontrout fish species.

Streams with American beaver Castor canadensis frequently had these structural characteristics and were significantly more likely to be occupied than ponds, lakes, streams without beaver, or streams with inactive beaver ponds, highlighting the importance of active manipulation of stream environments by beaver.

Native and non-native trout reduced the likelihood of spotted frog occupancy, especially where emergent vegetation cover was sparse. Intensive livestock grazing, low aquatic connectivity, and ephemeral hydroperiods were also negatively associated with spotted frog occupancy. We conclude that persistence of this species at the arid end of its range has been largely facilitated by habitat stability i. Use of olfactory cues by newly metamorphosed wood frogs Lithobates sylvaticus during emigration.

Juvenile amphibians are capable of long-distance upland movements, yet cues used for orientation during upland movements are poorly understood. We used newly metamorphosed Wood Frogs Lithobates sylvaticus to investigate: 1 the existence of innate i. In a circular arena experiment, animals with assumed innate directionality did not orient in the expected direction suggested by previous studies when deprived of visual and olfactory cues.

This suggests that juvenile Wood Frogs most likely rely on proximate cues for orientation. This finding is contrary to known habitat use by adult Wood Frogs during summer. Juvenile Wood Frogs were indifferent to the chemical signature of natal pond cattle tank water. Our findings suggest that management strategies for forest amphibians should consider key habitat features that potentially influence the orientation of juveniles during emigration movements, as well as adult behavior.

Trichobothrial mediation of an aquatic escape response: Directional jumps by the fishing spider, Dolomedes triton, foil frog attacks. Full Text Available Fishing spiders Pisauridae frequent the surfaces of ponds and streams and thereby expose themselves to predation by a variety of aquatic and semi-aquatic vertebrates. To assess the possibility that the impressive jumps of fishing spiders from the water surface function in evading attacks by frogs , attacks by bullfrogs Rana catesbiana and green frogs R.

Both the attack dynamics of the frogs and the evasive behaviors of the spiders were recorded at frames per second. A freeze-dried bullfrog, propelled toward spiders with acceleration, posture, and position that approximated the natural attack posture and dynamics, was used to assess the spiders' behavior. The involvement of the trichobothria leg hairs sensitive to air movements, and the eyes as sensory mediators of the evasion response was assessed.

Spiders with deactivated trichobothria were significantly impaired relative to intact and sham-deactivated spiders, and relative to spiders in total darkness. Thus, functional trichobothria, unlike the eyes, are both necessary and sufficient mediators of the evasion response. Measurements of air flow during frog attacks suggest that an exponential rise in flow velocity is the airborne signature of an attack. Big mountains but small barriers: population genetic structure of the Chinese wood frog Rana chensinensis in the Tsinling and Daba Mountain region of northern China.

Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns. Numerous studies have suggested that genetic differentiation among amphibian populations are particularly pronounced for populations separated by mountain ridges.

The Tsinling Mountain range of northern China is a major mountain chain that forms the boundary between the Oriental and Palearctic zoogeographic realms. We studied the population structure of the Chinese wood frog Rana chensinensis to test whether the Tsinling Mountains and the nearby Daba Mountains impose major barriers to gene flow.

Using 13 polymorphic microsatellite DNA loci, individuals from 12 breeding sites with geographical distances ranging from 2. Substantial genetic diversity was detected at all sites with an average of In addition, the genetic differentiation among the central populations was statistically significant, with pairwise FST values ranging from 0. Furthermore, hierarchical AMOVA analysis attributed most genetic variation to the within-population component, and the between-population variation can largely be explained by isolation-by-distance.

None of the putative barriers detected from genetic data coincided with the location of the Tsinling Mountains. The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R. High population connectivity and extensive juvenile dispersal may account for the significant, but moderate differentiation between populations.

Chinese wood frogs are able to use streams as breeding sites at high elevations, which may significantly contribute to the. Big mountains but small barriers: Population genetic structure of the Chinese wood frog Rana chensinensis in the Tsinling and Daba Mountain region of northern China. Full Text Available Abstract Background Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns.

Results Using 13 polymorphic microsatellite DNA loci, individuals from 12 breeding sites with geographical distances ranging from 2. Conclusion The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R. Chinese wood frogs are able to use streams as breeding sites at high.

Full Text Available Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape. In Brazil's Atlantic Forest, we evaluated frog richness and abundance by breeding guild at four distances from the edge of a reserve: i m inside the forest, ii 50 m inside the forest, iii at the forest edge, and iv 50 m inside three different converted habitats coffee plantation, non-native Eucalyptus plantation, and abandoned pastures, hereafter matrix types.

By sampling a dry and a wet season, we recorded individual frogs representing 29 species, of which three were undescribed. Breeding guild i. Leaf-litter and bromeliad breeders decreased in richness and abundance from the forest interior toward the matrix habitats. Water -body breeders increased in richness toward the matrix and remained relatively stable in abundance across distances. Number of large trees i. Twenty species found in the interior of the forest were not found in any matrix habitat.

Richness and abundance across breeding guilds were higher in the rainy season but frog distributions were similar across the four distances in the two seasons. Across matrix types, leaf-litter species primarily used Eucalyptus plantations, whereas water -body species primarily used coffee plantations. Bromeliad breeders were not found inside any matrix habitat. Our study highlights the importance of primary forest for bromeliad and leaf-litter breeders.

We propose that water -body breeders use edge and matrix habitats to reach breeding habitats along the valleys. Including life-history characteristics, such as breeding guild, can improve predictions of frog. Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape.

Including life-history characteristics, such as breeding guild, can improve predictions of frog distributions in. Large intestine bacterial flora of nonhibernating and hibernating leopard frogs Rana pipiens. The bacteria in the large intestines of 10 northern leopard frogs Rana pipiens were enumerated and partially characterized. Four nonhibernating frogs were collected in the summer, four hibernating frogs were collected in the winter, and two frogs just emerged from hibernation were collected in the spring.

All frogs had about 10 10 bacteria per g wet weight of intestinal contents and about 10 9 bacteria per g wet weight of mucosal scraping, although the counts from the winter frogs wer Terrestrial activity and conservation of adult California red-legged frogs Rana aurora draytonii in coastal forests and grasslands.

The federally threatened California red-legged frog Rana aurora draytonii occupies both aquatic and terrestrial habitats in its adult life stage. The terrestrial activities of this species are not well known and require documentation to assist in the development of appropriate levels of protection under the US Endangered Species Act.

In particular, we investigated 1 the use of terrestrial habitats by non-migrating adults in relation to season, breeding chronology, and precipitation, and 2 adult migration behavior, including seasonal timing, duration, distances traveled, and the use of corridors. All of the non-migrating frogs remained within m of their aquatic site of residence median days , despite frequent and copious rainfall.

Adult migration to and from breeding sites occurred from late October through mid-May wet season. We monitored 25 migration events between aquatic sites that were m apart. Short distance movements days, longer movements required up to 2 months. Most migrating frogs moved overland in approximately straight lines to target sites without apparent regard to vegetation type or topography.

Riparian corridors were neither essential nor preferred as migration routes. Frogs traveling overland occurred in upland habitats as far as m from water. Adequate protection of red-legged frog populations inhabiting. Apomorphine effects on frog locomotor behavior. The neuroanatomical pathways of the DA systems have been shown to be largely conserved across many vertebrate taxa. It is less certain whether the structural similarities seen between mammals and amphibians reflect a similar functional homology.

DA is well known for its role in facilitating motor behaviors in mammals. We investigated the effects of the nonspecific DA agonist, apomorp Vocal competition in male Xenopus laevis frogs. Male Xenopus laevis frogs produce underwater advertisement calls that attract gravid females and suppress calling by male competitors. Here we explore whether groups of males establish vocal ranks and whether auditory cues alone suffice for vocal suppression.

Tests of male—male pairs within assigned groups reveal linear vocal dominance relations, in which each male has a defined rank. Both the duration over which males interact, as well as the number of competitive opportunities, affect linea Cellular mechanisms of nociception in the frog.

Biogeographic patterns of Colombian frogs and toads. Using the data provided in Ruiz-Carranza et al. Some lowlands areas pacific lowlands, Amazonian exhibit high diversity species but lowlands areas in general are impoverished species , especially when contrasted with upland areas. The three Andean cordilleras harbor between 87 and species of frogs and toads, demonstrating that the biodiversity of Colombia resides primarily in its montane components, not in its lowland rain forests.

When biological endemicity is separated from political endemicity, five areas of high endemicity remain the three Andean cordilleras, the Sierra Nevada de Santa Marta, and the pacific lowlands. We endeavor to explain this description by recourse to cladistic analyses of several groups of leptodactylid frogs where we find that the general pattern of diversification is by means of horizontal diversification allopatric speciation with a minor contribution from vertical diversification.

Full Text Available The frogs of the Federal District of Brazil are listed and discussed as to habit, biology and ecology. The F. Its topography includes sea-shore, maritime scrub, lagoons, plains and marsh, open slopes, forested mountains and great heads of rock. Three thousand feet of altitude are attained at two points. Fifty two different frogs occur in the F. Three fifths of them live in open country. Two fifths of these have never been found above the plains; the others range higher but mostly in open country.

Their environment offers conditions suitable for average tadpoles and adults. There are six genera and thirty species. Two thirds of the latter belong to the type genera of the large neotropical families Bufonidae, Leptodactylidae and Hylidae.

Only in the maritime scrub formation are conditions somewhat different. Water for average tadpoles is provided by the lagoons. The xerophytism of the vegetation is, however, so marked that bromeliads growing on the ground provide almost the only appropriate shelter for adult tree- frogs used to sleeping upright on the vegetation.

One large Hylid genus lives entirely in them. It is casque-headed and phragmotic, shutting the lumen of the leaf-cup with head used as a plug. Another large Hylid genus shows a lesser degree of the same specialization. One genus with two species is entirely saxicolous; it lives on wet ledges of rock at all phases of its life history. Lutz The other two fifths of the frogs from F. Their environment offers numerous and varied biotopes and is near optimum for adults.

There is,however, hardly any standing water available for larvae. These frogs are ecologically diversified. They also show a general trend towards spawning in the adult biotipe, which leads to delayed hatching, semi-aquatic and terrestrial. Assessment of frog meat utilisation in Ibadan, Oyo state, Nigeria Frogs are among the most threatened species of wildlife in IUCN red list. Its utilisation in Ibadan, a major depot in western Nigeria was therefore conducted with the aim of assessing the forms and trend of use; and amongst others, reasons for frog meat consumption.

Data for the study were collected through questionnaire, Modeling potential river management conflicts between frogs and salmonids. Steven F. Railsback; Bret C. Harvey; Sarah J. Kupferberg; Margaret M. Management of regulated rivers for yellow-legged frogs Rana boylii and salmonids exemplifies potential conflicts among species adapted to different parts of the natural flow and temperature regimes.

Yellow-legged frogs oviposit in rivers in spring and depend on declining flows and warming temperatures for egg and tadpole survival and growth, A simple and inexpensive method of monitoring the movement of an isolated frog heart provides comparable results to those obtained with a force transducer. A commercially available photoresistor is integrated into a Wheatstone bridge circuit, and the output signal is interfaced directly with a recording device.

An excised, beating frog heart is…. Endocrine-disrupting effects and reproductive toxicity of low dose MCLR on male frogs Rana nigromaculata in vivo. However, MCLR concentrations in several water bodies have exceeded this level. Despite this recommended human safety standard, MCLR-induced endocrine-disrupting effects and reproductive toxicity on male frog Rana nigromaculata were demonstrated in this study.

Results showed that sperm motility and sperm count were significantly and negatively correlated with exposure time and concentration. By contrast, abnormal sperm rate was positively correlated with both parameters. Ultrastructural observation results revealed abnormal sperm morphologies, vacuoles in spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli.

These results indicated that MCLR could induce toxic effects on the reproductive system of frogs , significantly decrease testosterone content, and rapidly increase estradiol content. Prolonged exposure and increased concentration enhanced the relative expression levels of P aromatase and steroidogenic factor 1; thus, endocrine function in frogs was disrupted. This study provided a scientific basis of the global decline in amphibian populations.

Effects of mosquitofish Gambusia affinis cues on wood frog Lithobates sylvaticus tadpole activity. Full Text Available We examined the changes in activity of wood frog Lithobates sylvaticus tadpoles exposed to combinations of visual, chemical, and mechanical cues of the invasive mosquitofish Gambusia affinis.

We also examined whether the responses of the tadpoles to the predator cues were influenced by the short-term accumulation of chemical cues in the experimental container. In our experiment, the activity of wood frog L. Our experiment demonstrated that the repeated use of trial water can influence the activity level of tadpoles, regardless of the predator cue treatment used. Tadpoles in the first trial tended to be less active than tadpoles in subsequent trials. This effect does not appear to be mediated by the accumulation of predator cues since there was no significant interaction term.

Our results suggest that short-term accumulation of predator chemical cues do not affect the behavior of wood frog tadpoles: however, our results suggest that the repeated use of the same water in consecutive trials may affect tadpole behavior, perhaps through the accumulation of conspecific chemical cues.

In the late s, Rana muscosa mountain yellow-legged frog was common in the Tableland area of Sequoia National Park, California where it was possible to find hundreds of tadpoles and adults around many of the ponds and lakes. Surveys in demonstrated that R. Adult Alewife condition, assessed by the predicted weight of a mm fish 6. Spring Alewife condition was slightly less than the year average, but the fall value was well below the year average, likely due to increased Age-1 Alewife abundance.

The Age-1 Alewife abundance index was the highest observed in 40 years, and 8-times higher than the previous year. The Age-1 index estimates Alewife reproductive success the preceding year. The warm summer and winter of likely contributed to the large year class. In contrast the relatively cool spring and cold winter may result in a lower than average year class.

Abundance indices for Rainbow Smelt, Cisco, and Emerald Shiner either declined or remained at low levels in Pelagic prey fish diversity continues to be low since a single species, Alewife, dominates the catch. Deepwater Sculpin were the most abundant benthic prey fish in because Round Goby abundance declined sharply from Slimy Sculpin density continued to decline and the biomass index for US waters was the lowest ever observed. Anthropopression markers in lake bottom sediments.

Lakes are vulnerable to various types of anthropogenic disturbances. Responses of lake ecosystems to environmental stressors are varied and depend not only on the type of a factor but also on the lake natural resistance to degradation. It was assumed, that this impact manifests unevenly, depending on a type and degree of the pressure on the shore zones, water quality of tributaries, lake basin shape and dynamics of a water movement.

It was stated, that anthropogenic markers are substances accumulated in bottom sediments as a result of allochthonous substances inflow from the catchment and atmosphere. Along the selected transects samples from the top layer of sediments about 20 cm was collected representing the contemporary accumulation about 15 years. The research was conducted in the deepest points of each lake basin and along the research transects - while choosing the spots, the increased intensity of anthropogenic impact ports, roads with heavy traffic, wastewater discharge zones, built-up areas was taken into consideration.

The river outlets to the lake, where there are ecotonal zones between limnic and fluvial environment, were also taken into account. Analysis of the markers distribution was carried out against the diversity of chemical characteristics of limnic sediments. Ribbon shape of the lake basin and the dominant wind direction provide an opportunity of easy water mixing to a considerable depth.

Intensive waving processes cause removal of the matter from the littoral zone towards lake hollows separated by the underwater tresholds , where the. Monitoring changes in stream bottom sediments and benthic invertebrates. The study was conducted to determine whether the analysis of stream bottom sediments could be used to assess sediment pollution generated by highway construction. Most of the work completed to date has involved testing and refining methods for the co Grey Mangroove Avicemmia marina Forsk.

Monitoring of metals in Tilapia nilotica tissues, bottom sediments Tilapia Tilapia nilotica , bottom sediments and water were collected from Nworie River and Oguta Lake. The muscle, liver and gills of the fish as well as the bottom sediments and water were analysed for Al, Cr, Cd, Pb, As, Zn, Mn, Co, Se, Cu, Ni and Fe using atomic absorption spectrophotometer to highlight the importance Sorption behaviour of cobalt on Suez Canal bottom sediments.

Mineralogical, elemental analysis and sorption behaviour of the Suez Canal bottom sediments in the Port Said area were investigated. It was found that the bottom sediment consist mainly of quartz, feldspars and traces of calcite mineral. The cation-exchange capacity was found to increase as the particle size of the sediment decreased. Sorption of 60 Co by the bottom sediment increased with contact time up to 6 h. Variation of the solution pH from 4 to 9 showed limited increase in the sorption of 60 Co.

As carrier concentrations increase from 10 -7 N to 10 -3 N, sorption of Co was found to increase linearly following Freundlich isotherm. The desorption of 60 Co from bottom sediment with distilled and Suez Canal water was found to increase with contact time. Thorium content in bottom sediments of Pacific and Indian oceans. Presented are the results of Th distribution study in different substance-genetic types of bottom sediments of Pacific and Indian oceans.

Th content determination has been carried out by the method of instrumental neutron activation analysis. Th distribution maps in the surface layer of bottom sediments of Pacific and Indian oceans are drawn. It is noted that Indian ocean sediments are much richer with Th moreover Th distribution in different types of sediments is very non-uniform.

Non-uniformity of Th distribution in different types of Pacific ocean sediments is considerably less than that of Indian ocean and exceeds it only in red oozes. Characteristic features of acoustic profiling of bottom sediments in large oil storage tanks are considered.

Basic acoustic parameters of crude oil and bottom sediments are presented. It is shown that, because of the presence of both transition layers in crude oil and strong reverberation effects in oil tanks, the volume of bottom sediments that is calculated from an acoustic surface image is generally overestimated. To reduce the error, additional post-processing of acoustic profilometry data is proposed in combination with additional measurements of viscosity and tank density distributions in vertical at several points of the tank.

Uptake study of some radionuclides by Suez Canal bottom sediment. Chemical and physical analyses of Suez Canal bottom sediment at its south entrance Port Taweffek were carried out. The sediment was separated into its particle size fractions clay, silt and sand.

The different sediment fractions can be arranged with respect to their sorption capacity as follows: clay, natural sediment , sit and sand. The increase of pH results in small increase in the uptake reaching in some cases a maximum value of pH 6 or 8. Flotation technology was used for the cleaning of bottom sediments. Besides Oligochaeta, Chironomidae maggots and Bivalvia were detected.

Theappearance of Macrozoobenthos organisms can serve as a bioindicator of water quality. Microplastics in Baltic bottom sediments : Quantification procedures and first results. Microplastics in the marine environment are known as a global ecological problem but there are still no standardized analysis procedures for their quantification.

The first breakthrough in this direction was the NOAA Laboratory Methods for quantifying synthetic particles in water and sediments , but fibers numbers have been found to be underestimated with this approach. We propose modifications for these methods that will allow us to analyze microplastics in bottom sediments , including small fibers.

Addition of an internal standard to sediment samples and occasional empty runs are advised for analysis quality control. Distribution of microplastics in bottom sediments of the Russian part of the Baltic Sea is presented. All rights reserved. Trace elements distribution in bottom sediments from Amazon River estuary.

The Amazon River discharges into a dynamic marine environment where there have been many interactive processes affecting dissolved and particulate solids, either those settling on the shelf or reaching the ocean. Trace elemental concentration, especially of the rare earth elements, have been determined by neutron activation analysis in sixty bottom sediment samples of the Amazon River estuary, providing information for the spatial and temporal variation study of those elements.

Water bird characteristics, nutrient loadings, and the levels of bottom sediment silicon oxide SiO2 , aluminium oxide Al2O3 , ferric oxide Fe2O3 , calcium oxide CaO , copper Cu , phosphorus P and organic carbon C was studied in eight high altitude m small shallow 0. Utilization of bathymetry data to examine lead sediment contamination distributions in Lake Ontario.

Full Text Available Bathymetry data offer interesting opportunities for the analysis of contaminant distribution patterns. This research utilized lead surficial sediment sample data from Lake Ontario that were collected by the Canada Centre for Inland Waters in and Traditionally, two-dimensional analyses such as dot maps or proportional circle representation have been utilized to examine pollutant levels.

Generating area estimates allows for expanded spatial analysis of contaminant distribution patterns. Lake-wide surfaces were derived using the ordinary kriging technique. These were then layered on bathymetry data to examine three-dimensional relationships between observed pollution patterns and lake- bottom features. Spatial variability was observed in both the and datasets. Contamination levels in dropped substantially, especially in areas that were previously the most heavily polluted and above the Probable Effect Level Conversely, areas below the Threshold Effect Level increased from The dataset likely provides a more detailed estimation surface as there were more points available for interpolation procedures.

The kriging surfaces when combined with bathymetry, sedimentology information, and knowledge of physical processes provide a comprehensive illustration of the contaminant distributions whether they are high or when loadings are significantly reduced The results have implications for future sediment assessment programs and survey design on a lake-wide basis.

The bathymetry data allowed for enhanced interpretation and an improved understanding of observed lead pollution patterns. Particles of bottom and suspended sediments : height of rise. Full Text Available In the article, characteristic values of dynamic sizes of bottom and suspended sediments , including their probabilistic assessment, are considered.

The article presents the processing results in respect of the experimental data for bottom and suspended sediments , obtained in the laboratory environment using samples and filming methods. The experiments have proven that the dynamic hydraulic size determines the height of rise for the particles of the saltation load, rather than suspended ones.

In the laboratory environment, the maximal height of rise is mainly driven by the relative flow depth. According to the assessment made by the co-authors, depths of flows employed in the experiments designated for the identification of heights of rises, were comparable to saltation heights of particles. Besides, the saltation height of particles, having relative density well below 2.

Hydrodynamic conditions favourable for the separation and motion of artificial particles in coarse surface tanks are far different from the motion of sand particles on the bottom of lowland rivers. Values of hydraulic resistance ratios typical for laboratory experiments by far exceed their values typical for lowland rivers, and it means that the conditions of the experiments performed in the laboratory were similar to those typical for mountain rivers.

The research findings have proven that the particle separation and motion pattern, if artificial particles are made of the materials demonstrating variable density and elasticity values and if loose particles travel over fixed ones, is different from the pattern typical for natural particles having variable coarseness. Impact of bottom trawling on sediment characteristics - A study along inshore waters off Veraval coast, India.

The present communication is a study on the impact of bottom trawling on the sediment characteristics along Veraval coast, which is the largest trawler port of India. Experimental bottom trawling was conducted from MFV Sagarkripa at five transects Sources and sinks of microplastics in Canadian Lake Ontario nearshore, tributary and beach sediments.

Microplastics contamination of Lake Ontario sediments is investigated with the aim of identifying distribution patterns and hotspots in nearshore, tributary and beach depositional environments. Microplastics are concentrated in nearshore sediments in the vicinity of urban and industrial regions. The microplastic particles were primarily fibres and fragments microplastics in terms of how and where to implement preventative measures to reduce the contaminant influx.

Although the impacts of microplastics contamination on ecosystem health and functioning is uncertain, understanding, monitoring and preventing further microplastics contamination in Lake Ontario and the other Great Lakes is crucial. The distribution and abundance of gamma emitting radionuclides in Lake Ontario sediments. The distribution of gamma emitting radionuclides in Lake Ontario sediments was investigated. Samples were collected using a systematic design in the vicinity of Pickering and Darlington, and supplemented by lakewide offshore samples.

Naturally occurring 40 K was the predominant source of gamma activity. Sediment on the bottom of the water has been considered one of the water pollutants in the environmental management of Korea so treated as a management on pollutants, as you can see the examples in the dragging operation in the polluted sea area.

To healthily maintain and conserve the water ecosystem including bottom living things in the water, sediment on the bottom of the water should be recognized as the independent medium, which should maintain the certain quality like the water, the atmosphere, and soil, rather than the source of water pollution. Such recognition means that the management of sediment on the bottom of the water should change the fragmentary goal, centered the post management focusing on the water management, to the ecosystematic goal including the bottom living things.

In a point of the view, this study has a great significance to suggest not only the final goal for the management of sediment on the bottom of the water but also the necessity of developing the environmental standard of the sediment on the bottom of the water, which is a standard of the management or judgment in the actual managing the sediment on the bottom of the water - an estimation on the pollution of sediment , a removal of the polluted sediment , a purification of sediment , and an abandonment of the dragged sediment -, and the development measures.

Considering the situation that even the basic scheme related to the management of sediment is not prepared in the Government level, the concept of the environmental standard of sediment , the foreign example of the environmental standard of sediment , the current state of the domestic sediment pollution, and the development scheme of the environmental standard in this study must be the important foundation to establish the management system of sediment in the Government level.

Influence of break structures on the distribution of radionuclides in bottom sediments of the Kyiv reservoir. We study the distribution of radionuclides in bottom sediments of the Kyiv reservoir on the basis of research of adjacent territory break - block structures with deciphering space-born images and ground measurements and forecast the occurrence of extreme situations due to the redistribution of bottom water flows and sediments of radionuclides.

Dynamics of fluctuations of Cs contents in the bottom sediment in limnetic dam reservoir Goczalkowice. The results of Cs studies in bottom sediment in the Goczalkowice reservoir are presented. The determined coefficients of aquatic migration, difusion in bottom sediment and water in vertical section confirm zonal nature of Cs occurrance and accumulation in the reservoir.

Mercury in water and bottom sediments from a mexican reservoir. The Lerma-Santiago river's source is located in the State of Mexico. Its drainage basin occupies an area of , km2. The river receives urban wastewater discharges from 29 municipalities, as well as industrial water discharges, both treated and untreated, mainly from the industrial zones of Toluca, Lerma, Ocoyoacac, Santiago Tianguistengo, Pasteje and Atlacomulco.

The Jose Antonio Alzate Reservoir fed by the Lerma river is the first significant water reservoir downstream of the main industrial areas in the State of Mexico and both are considered the most contaminated water bodies in the State of Mexico. Mercury concentrations in water and bottom sediments in the Jose Antonio Alzate Reservoir were determined in 6 different sampling zones over a 1-year period.

Mercury was measured by instrumental neutron activation analysis INAA and irradiated with a thermal neutron flux of 9 x n. High variations of mercury concentrations in water in both, soluble and suspended forms, were observed to depend on the sampling season. During the rainy season, rain events contribute with a substantial water volume to modify physicochemical parameters like pH, which dilute chemical species in the Alzate Reservoir. There are evidence that in the Jose Antonio Alzate reservoir, sedimentation and adsorption act as a natural cleaning process, decreasing the dissolved concentrations and increasing the metallic content of the sediments.

A negative gradient was identified for mercury concentrations, from the Lerma river inlet to Alzate Reservoir dam, which demonstrates the considerable influence of the Lerma river inlet. This gradient also proves the existence of a metal recycling process between water and sediment , while the. Angeloni, D. E-mail: danielle. The theory that a large amount of sediment has been deposited into the HMP from the Speed River upstream over a number of years predicts the depressed oxygen levels, high nutrient-loading rates and the odour problems in the summer months.

The initial phase in the remediation plan for this project involved extensive background research and investigation. The focus was on determining the characteristics of the sediment and the history of the pond, to ultimately decide if the sediment was the source of the issues. Dissolved oxygen field tests and sediment sampling were conducted to get information on the magnitude of the problem and the environmental hazards potentially present in the pond. The pond was modelled utilising the Streeter-Phelps oxygen-sag model to predict the oxygen deficit.

These tests were conducted by using water samples obtained from various sample points at the pond. The proposed solution is a combined dredging and aeration approach. Mechanical dredging using a clamshell bucket and the installation of aerators is expected to solve the dissolved oxygen and water quality issues. Collection and preparation of bottom sediment samples for analysis of radionuclides and trace elements. The purpose of the document is to provide information on the methods for collecting sediments , the equipment used, and the sample preparation techniques for radionuclide and elemental analysis.

The most appropriate procedures for defining the strategies and criteria for selecting sampling locations, for sample storage and transportation are also given. Collection and preparation of stream and river bottom sediments , lake bottom sediments , estuary bottom sediments , and marine shallow bottom sediments are covered.

The document is intended to be a comprehensive manual for the collection and preparation of bottom sediments as a prerequisite to obtain representative and meaningful results using NATs. Although there are many approaches and methods available for sediment analyses, the scope of the report is limited to sample preparation for 1 analysis of radionuclides including sediment dating using radionuclides such as Pb and Cs and 2 analysis of trace, minor and major elements using nuclear and related analytical techniques such as NAA, XRF and PIXE.

Prospects of obtaining samples of bottom sediments from subglacial lake Vostok. Full Text Available The paper proves the timeliness of obtaining and examining bottom sediments from subglacial Lake Vostok. Predictive geological section of Lake Vostok and information value of bottom sediments have been examined. Severe requirements towards environmental security of lake examinations and sampling of bottom sediments rule out the use of conventional drilling technologies, as they would pollute the lake with injection liquid from the borehole.

In order to carry out sampling of bottom sediments from the subglacial lake, it is proposed to use a dynamically balanced tool string, which enables rotary drilling without any external support on borehole walls to transmit counter torque.

A theoretical analysis has been carried out to assess the operation of the tool string, which is a two-mass oscillatory electromechanical system of reciprocating and rotating motion RRM with two degrees of freedom. Infaunal macrobenthic community of soft bottom sediment in a tropical shelf.

Studies of benthic communities in tropical shelf waters are limited. In this study, we deal with the infaunal benthic community of soft bottom sediment of the tropical eastern Arabian Sea shelf. Benthic macroinfauna was sampled with a Smith Copper, zinc, molybdenum and uranium distribution in bottom sediments of the Black Sea.

Zhorov, V. Geologicheskikh Nauk. The results of investigations of bottom sediments of the Black Sea by four expeditions aboard scientific ships ''Academician Vernadsky'', ''Michael Lomonosov'', ''Academician Vavilov'' in , are presented. Charts of Cu, Zn, Mo and U distribution in modern, ancient Black Sea and neoeuxenic sediments of the basin are prepared.

Preferable uranium concentration in modern sediments , copper and molybdenum - in sapropelic muds of ancient Black Sea sediments and zinc - in neoeuxenic layers, is shown. Uranium geochemical behaviour is determined by physico-chemical regime of the basin, the presence of restoring situation which promotes the formation of uranium sorption-active forms in the upper layer of modern sediments.

Neither sapropelite organic matter , nor the peculiarities of lithological composition of sediments affect uranium behaviour. Bioassay of Lake Onego bottom sediments toxicity based on their chemical composition and deepwater macrozoobenthos state. Full Text Available The bioassay of the toxicity of bottom sediments sampled in different areas of Lake Onega was carried out by crustaceans biotesting Ceriodaphnia affinis Lillijeborg.

It was shown that in the most areas of Lake Onega there are non-toxic bottom sediments. Toxic bottom sediments were found in Kondopogskaya Bay, intensively polluted with pulp-and-paper mill wastewaters. For the first time in the deep central part of Lake Onega the area was revealed where the toxic bottom sediments contain a high content of iron, manganese and other trace elements typical for the central areas of the lake. The mapping of the bottom of Lake Onega was accomplished, and three zones were identified based on the analysis of the data concerning the chemical composition of bottom sediments , bioassay toxicity data and the results of the deepwater macrozoobenthos assessment.

For each zone the parameters of the main groups of benthos Amphipoda, Oligochaeta, Chironomidae were defined. The second zone is located mostly in the deep part of Petrozavodskaya Bay, where the most intensive development of amphipods is observed. The third area is identified for the first time: it is located in the central deep part of Lake Onega, where the communities of macrozoobenthos are limited by a natural toxic factor.

Radiocarbon dating of bottom sediments of the Red Sea. Results of radiocarbon dating of 23 cores 81 definitions sampled in the Red Sea rifton at 18 deg N are presented. Dating encompasses all major tectonic structures: the upper and the lower tectonic steps, saline scarp, axial zone. For sediments of the upper tectonic step the normal course of sedimentogenesis is detected, in all other structures with a strongly dissected topography redeposition and nonaccumulation of sediments are widely developed.

In Holocene the rate of sediment accumulation is 1. Phytotoxic effects of bottom sediments from Ignalina NPP wastewater canals and cooler. Samples of bottom sediments were collected from various wastewater canals of INPP, from the canal of wastewater treatment plant WWTP , small lake and rivulet, which are on the route of that wastes into Drukshiai. In , sites of Drukshiai were observed in order to assess the phytotoxicity of its bottom sediments.

The research was carried out in July of Number of somatic mutations pink, colourless and morphological and nonviable stamen hairs the quantity of whose indicates lethality, when hair contains less than 12 cells in Tradescantia clone 02 stamen hair SH system was counted. Genotoxic effect of bottom sediments on Tradescantia was estimated according to Sparrow et al.

As well as strong effect was when numbers of somatic mutations and non-viable stamen hairs exceeding 4. This test based on Magone method and lasted for 48 hours, after which time the seeds germination and root length of seedlings was measured. Estimations in both cases were run in triplicates. It was established that in accordance with the phytotoxic impact, the wastes discharged by INPP into Drukshiai in are attributed.

Age determination of bottom sediments from Lake Hovsgol, Mongolia. Dating plays a key role in determining past environmental changes in lake sediments cores. The pIRIR ages are always younger than 14 C ages from bulk samples, however, it was possible to construct the suitable age model based on luminescence and 14 C ages.

Therefore, pIRIR protocol can be contributed to estimate the sedimentation age of lake sediments as well as 14 C dating. Structural contour, isopach and feature maps of quaternary sediments in Western Lake Ontario. Six piston cores up to m long were collected to compare sediment lithology with key regional seismic reflectors.

Sediments deposited over the past 13, years were imaged with vertical resolution in the order of cm just below the lakebed and less than 1 m at the bedrock surface; resolution for the sleeve gun system is approximately m. Digital processing and rescaling of selected seismic profiles aided interpretation.

Structural contour maps for three Quaternary sequence boundaries and the bedrock surface were generated together with the related sequence isopach maps. Three additional maps portray lakebed features identified on sidescan sonar records and subsurface features identified on seismic profiles. All maps are at , scale. Strontium in the bottom sediments of some Finnish lakes. The maximum values occurred in Lake Naesijaervi. The local amount of deposition and the type of sediment were the most important factors affecting strontium values in sediments.

At some stations there was a clear maximum in a deeper sediment layer, which could be construed as a marker of the nuclear weapons tests in the s. Earthworms can accelerate the removal of contaminants from soil. The samples of sediment were used to assess of the potential phytotoxic effect of heavy metals on higher plants.

Total mortality was established in earthworms using chronic toxicity test after 7 and 28 exposure days. The largest concentration differences were recorded in the sample R7 after 7 days earthworms exposure. Our research will continue with determination of metals concentration in earthworms.

The effect of bottom sediment supplement on heavy metals content in plants Zea mays and soil. Full Text Available Important aspect of bottom sediments is the problem of their management or disposal after their extraction from the bottom of rivers, dam reservoirs, ports, channels or ponds. The research aimed at an assessment of potential environmental management of bottom sediment used as an admixture to light soil basing on its effect on contents of heavy metals in plants and soil. The research was conducted on light soil with granulometric structure of weakly loamy sand.

The sediment applied in the presented research revealed high share of silt and clay fractions, alkaline pH and low contents of heavy metals, therefore it may be used as an admixture to the above mentioned soils to improve their productivity. The applied bottom sediment to the soil affected a decreased in Zn, Cd and Pb content in maize in comparison with the treatment without the deposit whereas increased content of Cu, Cr and Ni.

No exceeded permissible content of heavy metals concerning plant assessment in view of their forage usability were registered in maize biomass. Uranium isotopes in waters and bottom sediments of rivers and lakes in Poland. Activity concentrations of U, U and U were determined in waters and bottom sediments in two main rivers in Poland the Vistula and Odra rivers with their tributaries, in four coastal rivers and six lakes.

Concentration of U and U were compared with the concentrations of Ra determined in another study. As compared with concentrations in coastal rivers and in lakes, enhanced concentrations of the radionuclides were observed in water and bottom sediments in the upper and middle courses of Vistula river, whereas in the Odra river the enhanced concentrations were present only in the bottom sediments. The enhanced concentrations in the Vistula river result from the discharge of coal mine waters from the Upper Silesian Coal Basin, and they indicate that the discharge was continued.

The enhanced concentration in Odra river observed only in bottom sediments indicate that the discharge occurred in the past. Accumulation and potential dissolution of Chernobyl-derived radionuclides in river bottom sediment. Areas contaminated with radionuclides from the Chernobyl nuclear accident have been identified in Pripyat River near the Chernobyl Nuclear Power Plant.

Several nuclear fuel particles have been preserved at cm depth that is the peak area of the concentrations of the radionuclides. Th ese inventories in the bottom sediments were compared with those of the released radionuclides during the accident. An analysis using a selective sequential extraction technique was applied for the radionuclides in the sediments.

Results suggest that the possibility of release of Cs and , Pu from the bottom sediment was low compared with 90 Sr. The potential dissolution and subsequent transport of 90 Sr from the river bottom sediment should be taken into account with respect to the long-term radiological influence on the aquatic environment. Patterns and sources of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in surficial sediments of Lakes Erie and Ontario.

Shen Li; Gewurtz, Sarah B. This study determines spatial trends and congener patterns of substituted polychlorinated dibenzo-p-dioxins PCDDs and polychlorinated dibenzofurans PCDFs in surficial sediments of Lakes Erie and Ontario. Erie and L. Ontario sediments. Heavy metal concentrations in Bottom Sediments of Ikpoba River Jun 23, Eichornia crassipes. This station was the lowest in depth during the dry season.

The water level however increased when it was heavily flooded during the rainy season. Activities here include making of sacrifices. Sediment Samples Collection, Preparation P and organic carbon C was Trace elements in bottom sediments of the Barents Sea on the standard section "Kola Meridian". Trace elements have been determined on atomic absorption spectrophotometer AA with mercury-hydride attachment HVG-1 of the company Shimadzu Japan by the methods of flaming acetylene — air and electrothermal atomization.

Common and very toxic trace elements include Pb, Cd, As, and Hg. The main sources of income in the Barents Sea are waters of the North Atlantic current and the large-scale atmospheric transport from industrialized Central Europe. As a rule the spatial distribution of trace elements is in good agreement with the granulometric composition of bottom sediments and the content of organic carbon. The contents of most of the listed trace elements in samples of bottom sediments on the standard section "Kola Meridian" in the Norwegian classification are consistent with background levels with the exception of Ni, Cr, and As.

Their content in bottom sediments at some stations has met the criteria for "slight" and "moderate" pollution. The obtained results confirm the insignificant levels of contamination of bottom sediments of some trace elements. On the status of stocks of commercial species of aquatic biological resources, the observed levels of contamination of bottom sediments in the investigated areas of the Barents Sea will have no significant effect.

Phosphorus availability from bottom sediments of lakes using a nuclear technique. Availability of phosphorus from the bottom sediments of a lake plays an import role in the development of aquatic biota and in the enhancement of eutrophication process. Samples analyzed were taken from the bottom sediments of the water bodies at different sites as well as from the shores.

The method is reliable and yields information of ecological significance. Availability of phosphorus from the bottom sediments of a lake plays an import role in the development of aquatic biota and in the enhancement of the eutrophication process. In this work, the 31 P- 32 P isotopic exchange E values technique was applied to assess the potential influence of this phosphorus 'reservoir' on the water quality of the Acaray and Yguazu Dams in the Easter Region of Paraguay. Samples analyzed were taken from the bottom sediments of the water body at different sites as well as from the shores.

The method is reliable and yields information of potential ecological significance. Occurance of geophilic of keratinophilic fungi in bottom sediments of lakes of various trophicity. Full Text Available The present investigations proved that colonization of bottom sediments with geophilie kerationophilic fungi in lakes of different trophicity was conditioned by the organic matter content. There was a relationship between occurrence of microorganisms and the basin management method.

The greatest concentration of keratinophilic fungi where species typical of sewages polluted with them dominated was found in sediments of a basin used for recreation. In sediments of a lake located in the agricultural region there was a domination of species charakteristic of pure water in respect to sanitary regulations.

The behavior of dissolved forms of Mn and Fe is considered from the viewpoint of their different solubility and formation of sulfides. The redox system of the Black Sea sediments can significantly be expanded at the expense of the migration methane and hydrogen, which accompanies its anaerobic oxidation.

Other parts are covered by estates of detached houses, barren lands and green areas. Bathymetric measurements and analyses of trace elements in bottom sediments were made in After 28 years of exploitation, reservoir's basin accumulated 43 thousand cubic metres of sediments i. Mean annual silting rate was 0. Due to the content of copper and chromium, bottom sediments were classified to the II category sediments of average pollution according to geochemical standards.

Concentrations of Pb, Cd and Hg in all analysed samples were below geochemical background. In a sample collected at the inlet to the reservoir, the TEL index for chromium was exceeded by River bottom sediment from the Vistula as matrix of candidate for a new reference material. Bottom sediments are very important in aquatic ecosystems. The sediments accumulate heavy metals and compounds belonging to the group of persistent organic pollutants. For the matrix of candidate of a new reference material, moisture content, particle size, loss on ignition, pH, and total organic carbon were determined.

For the candidate for a new reference material, homogeneity and analytes content were determined using a validated method. The results are a very important part of the development and certification of a new reference materials. The muddy bottom sediments of the old river beds of the lower Vistula. The bottom sediments of these water bodies were characterized by a low water content and organic matter content expressed as a percentage of dry weight, high organic matter content expressed in units of weight, as well as a high sediment oxygen demand.

Full Text Available Stability analysis of a levee made of the bottom sediments from Czorsztyn-Niedzica Reservoir is presented in the paper. These sediments were classified as silty sands and, based on the authors' own research, their geotechnical parameters were beneficial, so the possibility of using this material for the hydraulic embankments was considered. Stability and filtration calculations were carried out for a levee that had the same top width - 3 m, slope inclinations and different heights: 4, 6 and 8 m.

Two methods were used: analytical and numerical. Calculations were carried out without and with a steady and unsteady seepage filtration. Based on the analysis carried out it was stated that the levee made of the bottom sediments is stable even at the height of 8. Bottom currents and sediment waves on a shallow carbonate shelf, Northern Carnarvon Basin, Australia. The modern seafloor of the Australian Northwest Shelf between Exmouth and Dampier was analyzed for large scale sedimentary bedforms on 3D seismic reflection data.

The Carnarvon MegaSurvey of Petroleum Geo-Services PGS , a merged dataset of multiple industrial 3D seismic reflection surveys with a total size of 49, km2, offers an extensive view of the continental shelf, slope and rise of the Northern Carnarvon Basin. Over the shelf two fields of large scale sediment waves were observed in water depths between m, where the seafloor may be influenced by different processes including internal waves, tides and storms.

Based on the dimensions and orientations of the sediment waves the dominant direction and approximate strength of local bottom currents could be estimated. Information on local sediment grain-size distribution was provided by the auSEABED database allowing a classification of the observed sediment waves into sand- or mudwaves.

The first sediment wave field is positioned northwest of the Montebello Islands where the shelf is comparatively narrow and local sediment is mainly sand-sized. It most likely formed by increased bottom currents induced by the diversion of tidal flows around the islands. The second sediment wave field is located north of the Serrurier and Bessieres Islands within a local seafloor depression. Local sediments are poorly sorted, containing significant amounts of mud and gravel in addition to the mainly sand-sized grains.

The coarser sediment fraction could have been reworked to sandwaves by cyclone-induced bottom currents. Alternatively, the finer sediment fraction could form mudwaves shaped by less energetic along-slope oriented currents in the topographic depression.

The sediment waves consist partially of carbonate grains such as ooids and peloids that formed in shallow water during initial stages of the post glacial sea-level rise. These stranded carbonate grains thus formed in a different environment than the sediment. Monitoring of streams: macrozoobenthos and accumulation of heavy metals and radionuclides in bottom sediments.

To evaluate the environmental quality of streams in integrated monitoring sites IMS and agrostations AS , the macrozoobenthos communities and accumulation of heavy metals and radionuclides in bottom sediments were studied during Samples of macrozoobenthos were collected in stream biotopes which were recommended for monitoring. Community biodiversity was assessed by Shannon-Wiener and Simpson indices, and water quality of streams was estimated by Trent and Mean Chandler biotic indices.

Macrozoobenthos communities indicated that the studied streams were clean waters. The heavy metal concentrations in surficial sediments showed annual and seasonal changes and differences between monitoring sites. The Cu concentration in the soft turfy stream sediments at the Aukstaitija IMS was twice as high as that in sediments of other monitoring streams with hard sandy-gravel bottoms. During , the Ni concentration decreased, while levels of Cu, Cd and Cr were relatively stable.

The concentration of Cs was relatively stable in agrostation streams. Compared to levels in , an increase of Cs activity was observed in sediments at the Dzuklija IMS during Yankovich, Tamara L. Measurements of 35 parameters were taken, in addition to site-specific factors, such as sediment type, geology, proximity to radionuclide and contaminant sources, and others.

Reconstructing bottom water temperatures from measurements of temperature and thermal diffusivity in marine sediments. Continuous monitoring of oceanic bottom water temperatures is a complicated task, even in relatively easy-to-access basins like the North or Baltic seas. Here, a method to determine annual bottom water temperature variations from inverse modeling of instantaneous measurements of temperatures and sediment thermal properties is presented.

This concept is similar to climate reconstructions over several thousand years from deep borehole data. However, in contrast, the presented method aims at reconstructing the recent temperature history of the last year from sediment thermal properties and temperatures from only a few meters depth. For solving the heat equation, a commonly used forward model is introduced and analyzed: knowing the bottom water temperature variations for the preceding years and the thermal properties of the sediments , the forward model determines the sediment temperature field.

The bottom water temperature variation is modeled as an annual cosine defined by the mean temperature, the amplitude and a phase shift. As the forward model operator is non-linear but low-dimensional, common inversion schemes such as the Newton algorithm can be utilized. The algorithms are tested for artificial data with different noise levels and for two measured data sets: from the North Sea and from the Davis Strait. Both algorithms used show stable and satisfying results with reconstruction errors in the same magnitude as the initial data error.

In particular, the artificial data sets are reproduced with accuracy within the bounds of the artificial noise level. Apostolov, D. The samples were collected from the upper 5 cm layer of of the bottom sedimements together with fish from 5 points of Varna Bay and from 2 points of Saronicos Gulf in the summer of The results obtained proved to be important in investigating the ecological role of elements determined in connection with human activity in the studied area.

Geochemistry of aquatic and terrestrial sediments , Precambrian shield of southeastern Ontario. Lawrence Rivers, Ontario , Canada. Lake water alkalinity and pH patterns are similar to the distribution of carbonate components in glacial drift. Carbonate-rich drift derived from the Paleozoic limestone terrain on the northeast flank of the Precambrian Frontenac Arch has been dispersed in a south-westward direction across a variety of non-calcareous metasedimentary and igneous rocks of the Canadian Shield, providing a buffering capacity to lakes situated in granitic terrain.

The distribution patterns of mobile trace and minor elements are influenced by geochemical processes associated with subaerial weathering, ground and surface water transport, and the geochemical environment within the lakes themselves. Although composition of the drift is generally reflected by lake geochemistry, these post depositional processes can cause significant variations between patterns derived from the two sample types.

All regional geochemical patterns may show evidence of local enhancement caused by high concentrations of chemically distinctive minerals in drift or nearby bedrock. Natural and artificial radionuclides in the Suez Canal bottom sediments and stream water. The activity concentrations of U series, Th series and 40 K did not exceed The activity concentration of U series and 40 K did not exceed 0.

The activity concentrations of U series, Th series and 40K did not exceed The activity concentration of U series and 40K did not exceed 0. Nannofossils in upper quaternary bottom sediments of back-arc basins in the southwestern Pacific. The content of coccoliths and their taxonomic composition indicate warm subtropical-tropical conditions.

Long cores demonstrate a decrease in species diversity reflecting the transition from the cold late Pleistocene to the Holocene. Determination of solid flow for bottom sediment drag of Parana river using tracer techniques. Radioactive tracing technique with labeled sand was employed to evaluate the bottom sediment drag of Parana River, near Guaira City, State of Parana.

Dubai creek can be considered as the focal point of Dubai. It has great importance for trading and aesthetic values. Total and leachable heavy metals Cd, Co, Ni, Pb and Zn , organic carbon and total carbonate were studied in the bottom sediments of the creek.

Pollution Load Index, statistical analysis, were used in order to quantify the pollution load as well as to discriminate the data into significant groups. Normalization of the data using organic carbon and total carbonate was done in or Common and very toxic trace elements incl The U. Geological Survey, in cooperation with the U. Fish and Wildlife Service collected data on water and bottom-sediment chemistry to be used to evaluate a new water rights acquisition program designed to enhance wetland habitat in Stillwater National Wildlife Refuge and in Lahontan Valley, Churchill County, Nevada.

The area supports habitat critical to the feeding and resting of migratory birds travelling the Pacific Flyway. Information about how water rights acquisitions may affect the quality of water delivered to the wetlands is needed by stakeholders and Stillwater National Wildlife Refuge managers in order to evaluate the effectiveness of this approach to wetlands management. A network of six sites on waterways that deliver the majority of water to Refuge wetlands was established to monitor the quality of streamflow and bottom sediment.

Each site was visited every 4 to 6 weeks and selected water-quality field parameters were measured when flowing water was present. Water samples were collected at varying frequencies and analyzed for major ions, silica, and organic carbon, and for selected species of nitrogen and phosphorus, trace elements, pharmaceuticals, and other trace organic compounds.

Bottom-sediment samples were collected for analysis of selected trace elements. Dissolved-solids concentrations exceeded the recommended criterion for protection of aquatic life milligrams per liter in 33 of 62 filtered water samples.

The maximum arsenic criterion micrograms per liter was exceeded twice and the continuous criterion was exceeded seven times. Criteria protecting aquatic life from continuous exposure to aluminum, cadmium, lead, and mercury 87, 0. Mercury was the only trace element analyzed in bottom-sediment samples to exceed the published probable effect concentration 1, micrograms per kilogram.

Gamma-emitting radionuclides in the bottom sediments of some Finnish lakes. In and bottom sediment and surface water samples were taken from eight large lakes representing all five categories of deposition regions contaminated by the chernobyl fallout in Finland. All samples were analysed for gamma-emitting radionuclides.

The other radionuclides of Chernobyl origin detected in water samples were Ru, Sb and Cs. The maximum values were in Lake Pyhaejaervi. In addition to the cesium isotopes Cs and Cs , Chernobyl derived Ru, Sb amd Ce were detected i the surface layer of sediment in most lakes. In the maximum concentrations of Cs and Cs were in the uppermost layer of sediment cm at almost all stations. In , the cesium peaks already occurred at many stations in the second slice cm , which may indicate downward diffusion of cesium in sediments or mixing of sediment layers during sampling.

The most important factors affecting cesium values in sediments were the local amount of deposition and the type of sediment. This study did not reveal any correletion between the maximum depth of the lake and the area of the lake with the cesium amounts in the sediments. The increase of 9 0Sr concentrations in the Black Sea bottom sediments along to western coast of the Black Sea and south part of Crimea was observed in years.

To our opinion, it was connected with hydrological processes for example, currents , occurring in the given sea parts. The most polluted by post-Chernobyl 9 0Sr areas were bottom sediments of Dnieper, Dniester and Danube River deltas, territory of an arrangement of a main channel of the North-Crimea Channel - region of a peninsula Tarkhankut, southeast part of Crimea Feodosiya area.

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Zukal, Jan; Bandouchova, Hana; Brichta, Jiri; Cmokova, Adela; Jaron, Kamil S; from the mainland with 30 from an island in the state of Espírito Santo, Brazil. Our results suggest a strong selective pressure on males to shift the time invested in tadpole transport to periods of low intra-specific competition. Parzych S. Variables considered for the second task were initial capital investments, fuel savings, depreciation tax benefits, salvage values, and service/maintenance costs. gazowo. VII mgr inż. Kamil Kowalski. Wpływ warstw fluorkowych i węglanowych na odporność korozyjną materiałów na bazie magnezu. VII.