62 years of population dynamics of European perch (Perca fluviatilis) in a mesotrophic lake tracked using angler diaries: The role of commercial fishing, predation and temperature

DEFF Research Database (Denmark)

Skov, Christian; Jansen, Teunis; Arlinghaus, Robert

2017-01-01

(abundance, mean size and record size) of European perch (Perca fluviatilis L.) in relation to the impact of three commercial fishers with different fishing strategies, pike (Esox lucius L.) predation and temperature. We found that anglers’ harvest rates of perch varied by a factor of 10 over time......, but it also underlines the need for supplementary data on biotic and abiotic factors to reach the full potential of angler diary data...

Experimental infection with epizootic haematopoietic necrosis virus (EHNV of rainbow trout (Oncorhynchus mykiss Walbaum and European perch (Perca fluviatilis L.

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Borzym Ewa

2015-12-01

Full Text Available The aim of this study was the determination of the susceptibility of Polish farmed redfin perch (Perca fluviatilis L. and rainbow trout (Oncorhynchus mykiss Walbaum to experimental infection with haematopoietic necrosis virus (EHNV. A bath challenge model was tested at two temperature ranges: 13-15°C and 20-22°C. After 7 d, the first clinical signs and mortality were observed in fish kept at these temperatures. Significantly more mortality cases were reported in the redfin perch population, reaching a maximum of 24% compared with 12% in the rainbow trout group at 20-22°C. EHNV was reisolated from redfin perch and rainbow trout tissue in cell culture and the infection was confirmed by a molecular method and histopathology during the duration of the experiment. This study revealed that fish from Polish farms can be susceptible to EHNV even at lower temperatures.

Biochemical and ultrastructural changes in the liver of European perch (Perca fluviatilis L. in response to cyanobacterial bloom in the Gruža reservoir

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Perendija Branka R.

2011-01-01

Full Text Available We investigated the biochemical and ultrastructural changes in the liver of the freshwater fish, European perch (Perca fluviatilis, in response to Aphanizomenon flos-aquae bloom in the Gruža Reservoir, Serbia. The activities of total manganese- and copper zinc-containing superoxide dismutase (Tot SOD, Mn-SOD, Cu/Zn-SOD, catalase (CAT, glutathione peroxidase (GSH-Px, glutathione reductase (GR and biotransformation phase II enzyme glutathione-S-transferase (GST, as well as concentrations of total glutathione (GSH and sulfhydryl (-SH groups were examined before and during the bloom period. Mn-SOD activity was significantly higher, while the activities of Cu/Zn-SOD, CAT and GSH-Px and the concentration of the -SH groups were significantly lower during the bloom. The ultrastructure of the liver revealed necrotic and apoptotic damage to the hepatocytes during the bloom period. Our work represents the first study to report the influences of an Aphanizomenon flos-aquae bloom in the Gruža Reservoir on antioxidant biomarkers and on histopathological alterations in the liver of the freshwater fish European perch (Perca fluviatilis.

Effects of turbidity and prey density on the foraging success of age 0 year yellow perch Perca flavescens.

Science.gov (United States)

Wellington, C G; Mayer, C M; Bossenbroek, J M; Stroh, N A

2010-05-01

Laboratory experiments were conducted to determine how larval and juvenile yellow perch Perca flavescens respond to changes in prey density when exposed to different levels and types of turbidity (phytoplanktonic or sedimentary). Across prey densities, consumption by P. flavescens tended to be less in phytoplanktonic turbidity compared with sedimentary turbidity. For larvae, this effect was dependent on turbidity level (consumption differed between turbidity types only at high turbidity), while for juveniles the difference with turbidity type was equal across turbidity levels. These results suggest that phytoplankton blooms are detrimental to the ability of late season age 0 year P. flavescens to forage and support the need to control factors leading to excessive phytoplankton growth in lakes.

The Effect of Parasite Infection on Stable Isotope Turnover Rates of δ15N, δ13C and δ34S in Multiple Tissues of Eurasian Perch Perca fluviatilis.

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Elizabeth Yohannes

Full Text Available Stable isotope analysis of commercially and ecologically important fish can improve understanding of life-history and trophic ecology. However, accurate interpretation of stable isotope values requires knowledge of tissue-specific isotopic turnover that will help to describe differences in the isotopic composition of tissues and diet. We performed a diet-switch experiment using captive-reared parasite-free Eurasian perch (Perca fluviatilis and wild caught specimens of the same species, infected with the pike tapeworm Triaenophorus nodulosus living in host liver tissue. We hypothesize that metabolic processes related to infection status play a major role in isotopic turnover and examined the influence of parasite infection on isotopic turn-over rate of carbon (δ13C, nitrogen (δ15N and sulphur (δ34S in liver, blood and muscle. The δ15N and δ13C turnovers were fastest in liver tissues, followed by blood and muscle. In infected fish, liver and blood δ15N and δ13C turnover rates were similar. However, in infected fish, liver and blood δ13C turnover was faster than that of δ15N. Moreover, in infected subjects, liver δ15N and δ13C turnover rates were three to five times faster than in livers of uninfected subjects (isotopic half-life of ca.3-4 days compared to 16 and 10 days, respectively. Blood δ34S turnover rate were about twice faster in non-infected individuals implying that parasite infection could retard the turnover rate of δ34S and sulphur containing amino acids. Slower turnover rate of essential amino acid could probably decrease individual immune function. These indicate potential hidden costs of chronic and persistent infections that may have accumulated adverse effects and might eventually impair life-history fitness. For the first time, we were able to shift the isotope values of parasites encapsulated in the liver by changing the dietary source of the host. We also report variability in isotopic turnover rates between tissues

Observations of Eurasian perch (Perca fluviatilis L. post-larvae growth performances reared in an illuminated floating cage in Varese lake (N-W Italy over a two years period

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Micaela Antonini

2010-02-01

Full Text Available Eurasian perch (P. fluviatilis is a very important fish species in Varese lake (N-W Italy. Since the second half of 20th century, perch catches in the lake have steadily decreased and by the end of the ‘80s the species resulted clearly endangered. The purpose of this study was to investigate growth, mortality and feeding conditions of perch postlarvae, reared in illuminated floating cage in Varese lake, to obtain fingerlings for a restocking program. In June 2006 and 2007, groups of 280 and 300 pre-weaned post-larvae (average body weight 0.64±0.09 g and 0.25±0.08 g respectively P<0.01 were held in an illuminated net cage for 90 days. The cage was illuminated inside from 20:30 p.m. to 6:30 a.m. During the trial, the nightly zooplankton accumulation inside the cage was assessed weekly. At night time the zooplankton biomass, which resulted dominated by Cladocera family, was higher inside the cage than in the lake. In 2006, 322±36 zooplankters L–1 were observed, compared to 945±600 observed in 2007 (P<0.05. In the lake, the number of zooplankters per litre was similar in both years, resulting in 63.3±50.30 and 61.10±45 zooplankters L–1, respectively on 2006 and 2007. In order to assess perch growth performances, 25 fishes were sampled from the cage every 15-20 days and length (cm and weight (g were assessed for each sample. At the end of September, specific growth rate (SGR and survival rate were assessed. In 2006 the final mean body weight of the perch fry was 4.65±1.47 g and that results significantly lower (P<0.05 than of 2007 (6.3±1.69 g. The SGR was 2.04% and 3.42%, respectively. The higher growth rate observed in 2007 was influenced by a higher zooplankton accumulation in the cage due to an improved cage management. In order to assess the cage efficiency, in September 2006 and 2007, the weight of young-of-year perch (n=50 captured in the lake were compared to those of reared fish. Wild fry showed a mean body weight significantly

A comparative assessment of the adrenotoxic effects of cadmium in two teleost species, rainbow trout, Oncorhynchus mykiss, and yellow perch, Perca flavescens

Energy Technology Data Exchange (ETDEWEB)

Lacroix, Alexandra; Hontela, Alice

2004-03-30

Rainbow trout (Oncorhynchus mykiss) and yellow perch (Perca flavescens) have a different sensitivity to cadmium (Cd) in vivo (troutperch). Metals and particularly Cd impair cortisol secretion by adrenocortical cells in both species. The purpose of the present study was to assess in vitro the effect of Cd on cortisol secretion by adrenocortical cells of trout and perch, to compare the sensitivity of adrenal steroidogenesis in these two teleosts. Adrenocortical cells were exposed to Cd for 60 min, then stimulated with ACTH, dbcAMP or with pregnenolone, a cortisol precursor. Cd inhibited ACTH-stimulated cortisol secretion in a dose-dependent manner in both fish species, however, the EC50s (concentration resulting in 50% inhibition of cortisol secretion) was significantly lower in trout (EC50=0.09 mM) than perch (EC50=0.26 mM). To test the specificity of Cd to act as an endocrine disrupter, the LC50 (concentration that kills 50% of the cells) was also evaluated to determine the LC50/EC50 ratio (LC50/EC50{sub O.mykiss}=175.6>LC50/EC50{sub P.flavescens}=37.7). Adrenocortical cells of trout were more sensitive than those of perch and Cd had a higher endocrine-disrupting potential and specificity in trout than in perch. However, in both species, Cd had the same effect on ACTH, dbcAMP and pregnenolone-stimulated cortisol secretion, with pregnenolone maintaining cortisol secretion until cell viability was impaired. These results confirm that for both species, Cd interferes in the signalling pathway of cortisol synthesis in a step prior to the pregnenolone formation. Data provided by the present study revealed important differences in vulnerability of adrenal steroidogenesis between rainbow trout and yellow perch.

First evidence of the possible implication of the 11-deoxycorticosterone (DOC) in immune activity of Eurasian perch (Perca fluviatilis, L.): comparison with cortisol.

Science.gov (United States)

Mathieu, Cédric; Milla, Sylvain; Mandiki, S N M; Douxfils, Jessica; Douny, Caroline; Scippo, Marie-Louise; De Pauw, Edwin; Kestemont, Patrick

2013-06-01

Cortisol, the main corticosteroid in fish, is frequently described as a modulator of fish immune system. Moreover, 11-deoxycorticosterone (DOC) was shown to bind and transcriptionally activate the mineralocorticoid receptor and may act as a mineralocorticoid in fish. Immune modulations induced by intraperitoneal injections of these two corticosteroids were assessed in Eurasian perch juveniles. Cortisol and DOC were injected at 0.8 mg kg(-1) and 0.08 mg kg(-1) body weight respectively. Cortisol increased plasma lysozyme activity 72 h post-injection, C-type lysozyme expression in spleen from 1 to 72 h post-injection, and favoured blood neutrophils at the expense of a mixture of lymphocytes and thrombocytes. Moreover, 6 h after injection, cortisol reduced expression levels of the pro-inflammatory cytokine TNF-α in spleen. DOC had no effects on the immune variables measured in plasma, but increased expression levels of C-type lysozyme and apolipoprotein A1 mRNA in both gills and spleen. Meanwhile, DOC stimulated its putative signalling pathway by increasing expression of mineralocorticoid receptor and 11β-hydroxysteroid dehydrogenase-2 in spleen. These results confirmed the role of cortisol as an innate, short term immune stimulator. For the first time, DOC is described as a possible immune stimulator in fish. Copyright © 2013 Elsevier Inc. All rights reserved.

Hanging out at the airport: Unusual upside-down perching behavior by Eurasian Jackdaws (Corvus monedula) in a human-dominated environment

Science.gov (United States)

Katzner, Todd E.

2016-01-01

Animals occupying human-dominated environments show the capacity for behavioral flexibility. Corvids are among the most intelligent synanthropic bird species. During a layover at Schipol Airport in Amsterdam, Netherlands, I photographically documented Eurasian Jackdaws (Corvus monedula) perching upside down from a building cornice. In contrast to other reports of hanging birds, these jackdaws did not forage or play while upside down and appeared to use the perching spot to observe their surroundings. Although Corvids and Psittacines are known to hang upside down, especially in captive situations, such behaviors are rarely documented in the wild, and never before in association with human-built structures.

Plasma osmolality and oxygen consumption of perch Perca fluviatilis in response to different salinities and temperatures

DEFF Research Database (Denmark)

Christensen, Emil Aputsiaq Flindt; Svendsen, Morten Bo Søndergaard; Steffensen, John Fleng

2017-01-01

with salinity at 10 and 20° C. Maximum metabolic rate (MMR) and aerobic scope was lowest at salinity of 15 at 5° C, yet at 20° C, they were lowest at a salinity of 0. A cost of osmoregulation (SMR at a salinity of 0 and 15 compared with SMR at a salinity of 10) could only be detected at a salinity of 15 at 20...... of osmoregulation (28%) at a salinity of 15 at 20° C indicates that the cost of osmoregulation in P. fluviatilis increases with temperature under hyperosmotic conditions and a power analysis showed that the cost of osmoregulation could be lower than 12·5% under other environmental conditions. The effect of salinity......The present study determined the blood plasma osmolality and oxygen consumption of the perch Perca fluviatilis at different salinities (0, 10 and 15) and temperatures (5, 10 and 20° C). Blood plasma osmolality increased with salinity at all temperatures. Standard metabolic rate (SMR) increased...

Expression kinetics of key genes in the early innate immune response to Great Lakes viral hemorrhagic septicemia virus IVb infection in yellow perch (Perca flavescens)

Science.gov (United States)

Olson, Wendy; Emmenegger, Eveline; Glenn, Jolene; Simchick, Crystal; Winton, Jim; Goetz, Frederick

2013-01-01

The recently discovered strain of viral hemorrhagic septicemia virus, VHSV-IVb, represents an example of the introduction of an extremely pathogenic rhabdovirus capable of infecting a wide variety of new fish species in a new host-environment. The goal of the present study was to delineate the expression kinetics of key genes in the innate immune response relative to the very early stages of VHSV-IVb infection using the yellow perch (Perca flavescens) as a model. Administration of VHSV-IVb by IP-injection into juvenile yellow perch resulted in 84% cumulative mortality, indicating their high susceptibility to this disease. In fish sampled in the very early stages of infection, a significant up-regulation of Mx gene expression in the liver, as well as IL-1β and SAA activation in the head kidney, spleen, and liver was directly correlated to viral load. The potential down-regulation of Mx in the hematopoietic tissues, head kidney and spleen, may represent a strategy utilized by the virus to increase replication.

Branchial cadmium and copper binding and intestinal cadmium uptake in wild yellow perch (Perca flavescens) from clean and metal-contaminated lakes

International Nuclear Information System (INIS)

Klinck, J.S.; Green, W.W.; Mirza, R.S.; Nadella, S.R.; Chowdhury, M.J.; Wood, C.M.; Pyle, G.G.

2007-01-01

Branchial binding kinetics and gastro-intestinal uptake of copper and cadmium where examined in yellow perch (Perca flavescens) from a metal-contaminated lake (Hannah Lake, Sudbury, Ontario, Canada) and an uncontaminated lake (James Lake, North Bay, Ontario, Canada). An in vivo approach was taken for gill binding comparisons while an in vitro gut binding assay was employed for gastro-intestinal tract (GIT) uptake analysis. By investigating metal uptake at the gill and the gut we cover the two main routes of metal entry into fish. Comparisons of water and sediment chemistries, metal burdens in benthic invertebrate, and metal burdens in the livers of perch from the two study lakes clearly show that yellow perch from Hannah L. are chronically exposed to a highly metal-contaminated environment compared to a reference lake. We found that metal-contaminated yellow perch showed no significant difference in gill Cd binding compared to reference fish, but they did show significant decreases in new Cd binding and absorption in their GITs. The results show that gill Cd binding may involve low-capacity, high-affinity binding sites, while gastro-intestinal Cd uptake involves binding sites that are high-capacity, low-affinity. From this we infer that Cd may be more critically controlled at the gut rather than gills. Significant differences in branchial Cu binding (increased binding) were observed in metal-contaminated yellow perch. We suggest that chronic waterborne exposure to Cu (and/or other metals) may be the dominant influence in gill Cu binding rather than chronic exposure to high Cu diets. We give supporting evidence that Cd is taken up in the GIT, at least in part, by a similar pathway as Ca 2+ , principally that elevated dietary Ca 2+ reduces Cd binding and uptake. Overall our study reveals that metal pre-exposure via water and diet can alter uptake kinetics of Cu and Cd at the gill and/or the gut

Branchial cadmium and copper binding and intestinal cadmium uptake in wild yellow perch (Perca flavescens) from clean and metal-contaminated lakes

Energy Technology Data Exchange (ETDEWEB)

Klinck, J.S. [Department of Biology, McMaster University, Hamilton, Ont. L8S 4K1 (Canada)], E-mail: klinckjs@mcmaster.ca; Green, W.W.; Mirza, R.S. [Department of Biology, McMaster University, Hamilton, Ont. L8S 4K1 (Canada); Department of Biology, Nipissing University, North Bay, Ont. P1B 8L7 (Canada); Nadella, S.R.; Chowdhury, M.J.; Wood, C.M. [Department of Biology, McMaster University, Hamilton, Ont. L8S 4K1 (Canada); Pyle, G.G. [Department of Biology, Nipissing University, North Bay, Ont. P1B 8L7 (Canada)

2007-08-30

Branchial binding kinetics and gastro-intestinal uptake of copper and cadmium where examined in yellow perch (Perca flavescens) from a metal-contaminated lake (Hannah Lake, Sudbury, Ontario, Canada) and an uncontaminated lake (James Lake, North Bay, Ontario, Canada). An in vivo approach was taken for gill binding comparisons while an in vitro gut binding assay was employed for gastro-intestinal tract (GIT) uptake analysis. By investigating metal uptake at the gill and the gut we cover the two main routes of metal entry into fish. Comparisons of water and sediment chemistries, metal burdens in benthic invertebrate, and metal burdens in the livers of perch from the two study lakes clearly show that yellow perch from Hannah L. are chronically exposed to a highly metal-contaminated environment compared to a reference lake. We found that metal-contaminated yellow perch showed no significant difference in gill Cd binding compared to reference fish, but they did show significant decreases in new Cd binding and absorption in their GITs. The results show that gill Cd binding may involve low-capacity, high-affinity binding sites, while gastro-intestinal Cd uptake involves binding sites that are high-capacity, low-affinity. From this we infer that Cd may be more critically controlled at the gut rather than gills. Significant differences in branchial Cu binding (increased binding) were observed in metal-contaminated yellow perch. We suggest that chronic waterborne exposure to Cu (and/or other metals) may be the dominant influence in gill Cu binding rather than chronic exposure to high Cu diets. We give supporting evidence that Cd is taken up in the GIT, at least in part, by a similar pathway as Ca{sup 2+}, principally that elevated dietary Ca{sup 2+} reduces Cd binding and uptake. Overall our study reveals that metal pre-exposure via water and diet can alter uptake kinetics of Cu and Cd at the gill and/or the gut.

Seasonal variations in hepatic Cd and Cu concentrations and in the sub-cellular distribution of these metals in juvenile yellow perch (Perca flavescens)

International Nuclear Information System (INIS)

Kraemer, Lisa D.; Campbell, Peter G.C.; Hare, Landis

2006-01-01

Temporal fluctuations in metal (Cd and Cu) concentrations were monitored over four months (May to August) in the liver of juvenile yellow perch (Perca flavescens) sampled from four lakes situated along a metal concentration gradient in northwestern Quebec: Lake Opasatica (reference lake, low metal concentrations), Lake Vaudray (moderate metal concentrations) and lakes Osisko and Dufault (high metal levels). The objectives of this study were to determine if hepatic metal concentrations and metal-handling strategies at the sub-cellular level varied seasonally. Our results showed that Cd and Cu concentrations varied most, in both absolute and relative values, in fish with the highest hepatic metal concentrations, whereas fish sampled from the reference lake did not show any significant variation. To examine the sub-cellular partitioning of these two metals, we used a differential centrifugation technique that allowed the separation of cellular debris, metal detoxified fractions (heat-stable proteins such as metallothionein) and metal sensitive fractions (heat-denaturable proteins (HDP) and organelles). Whereas Cd concentrations in organelle and HDP fractions were maintained at low concentrations in perch from Lakes Opasatica and Vaudray, concentrations in these sensitive fractions were higher and more variable in perch from Lakes Dufault and Osisko, suggesting that there may be some liver dysfunction in these two fish populations. Similarly, Cu concentrations in these sensitive fractions were higher and more variable in perch from the two most Cu-contaminated lakes (Dufault and Osisko) than in perch from the other two lakes, suggesting a breakdown of homeostatic control over this metal. These results suggest not only that metal concentrations vary seasonally, but also that concentrations vary most in fish from contaminated sites. Furthermore, at the sub-cellular level, homeostatic control of metal concentrations in metal-sensitive fractions is difficult to maintain in

The first isolation of a rhabdovirus from perch (Perca fluviatilis) in Norway

DEFF Research Database (Denmark)

Dannevig, B.H.; Olesen, Niels Jørgen; Jentoft, S.

2001-01-01

was stained in IF with rabbit antisera against perch rhabdovirus, pike rhabdovirus and lake trout rhabdovirus and neutralised by anti perch rhabdovirus indicating. that the Norwegian perch virus is closely related to these viruses belonging to the Vesiculovirus genus of the family Rhabdoviridae...

The first isolation of a rhabdovirus from perch (Perca fluviatilis) in Norway

DEFF Research Database (Denmark)

Dannevig, B.H.; Olesen, Niels Jørgen; Jentoft, S.

2001-01-01

was stained in IF with rabbit antisera against perch rhabdovirus, pike rhabdovirus and lake trout rhabdovirus and neutralised by anti perch rhabdovirus indicating that the Norwegian perch virus is closely related to these viruses belonging to the Vesiculovirus genus of the family Rhabdoviridae...

Perch, Perca fluviatilis show a directional preference for, but do not increase attacks toward, prey in response to water-borne cortisol

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Lindsay J. Henderson

2017-10-01

Full Text Available In freshwater environments, chemosensory cues play an important role in predator-prey interactions. Prey use a variety of chemosensory cues to detect and avoid predators. However, whether predators use the chemical cues released by disturbed or stressed prey has received less attention. Here we tested the hypothesis that the disturbance cue cortisol, in conjunction with visual cues of prey, elevates predatory behavior. We presented predators (perch, Perca fluviatilis with three chemosensory choice tests and recorded their location, orientation, and aggressive behavior. We compared the responses of predators when provided with (i visual cues of prey only (two adjacent tanks containing sticklebacks; (ii visual and natural chemical cues of prey vs. visual cues only; and (iii visual cues of prey with cortisol vs. visual cues only. Perch spent a significantly higher proportion of time in proximity to prey, and orientated toward prey more, when presented with a cortisol stimulus plus visual cues, relative to presentations of visual and natural chemical cues of prey, or visual cues of prey only. There was a trend that perch directed a higher proportion of predatory behaviors (number of lunges toward sticklebacks when presented with a cortisol stimulus plus visual cues, relative to the other chemosensory conditions. But they did not show a significant increase in total predatory behavior in response to cortisol. Therefore, it is not clear whether water-borne cortisol, in conjunction with visual cues of prey, affects predatory behavior. Our results provide evidence that cortisol could be a source of public information about prey state and/or disturbance, but further work is required to confirm this.

Concentrations of 17 elements in the zebra mussel (Dreissena polymorpha), in different tissues of perch (Perca fluviatilis), and in perch intestinal parasites (Acanthocephalus lucii) from the subalpine lake Mondsee, Austria

Energy Technology Data Exchange (ETDEWEB)

Sures, B.; Steiner, W.; Rydlo, M.; Taraschewski, H.

1999-11-01

Concentrations of the elements Al, Ag, Ba, ca, Cd, Co, Cr, cu, Fe, Ga, Mg, Mn, Ni, Pb, Sr, Tl, and Zn were analyzed by inductively coupled plasma mass spectrometry in the acanthocephalan Acanthocephalus lucii (Mueller); in its host, Perca fluviatilis (L.), and in the soft tissue of the zebra mussel, Dreissena polymorpha (Pallas). All animals were collected from the same sampling site in a subalpine lake, Mondsee, in Austria. Most of the elements were found at significantly higher concentrations in the acanthocephalan than in different tissues (muscle, liver, and intestinal wall) of its perch host. Only Co was concentrated in the liver of perch to a level that was significantly higher than that found in the parasite. Most of the analyzed elements were also present at significantly higher concentrations in A. lucii than in D. polymorpha. Barium and Cr were the only elements recorded at higher concentrations in the mussel compared with the acanthocephalan. Thus, when comparing the accumulation of elements, the acanthocephalans appear to be even more suitable than the zebra mussels in terms of their use in the detection of metal contamination within aquatic biotopes. Spearman correlation analysis revealed that the concentrations of several elements within the parasites decreased with increasing infrapopulation. Furthermore, the levels of some elements in the perch liver were negatively correlated with the weight of A. lucii in the intestine. Thus, it emerged that not only is there competition for elements between acanthocephalans inside the gut but there is also competition for these elements between the host and the parasites. The elevated element concentrations demonstrated here in the parasitic worm A. lucii provide support for further investigations of these common helminthes and of their accumulation properties.

How does exposure to nickel and cadmium affect the transcriptome of yellow perch (Perca flavescens) – Results from a 1000 candidate-gene microarray

International Nuclear Information System (INIS)

Bougas, Bérénice; Normandeau, Eric; Pierron, Fabien; Campbell, Peter G.C.; Bernatchez, Louis; Couture, Patrice

2013-01-01

Highlights: •The transcriptional responses of Perca flavescens to both metal and non metal stressors were measured with a 1000 candidate-gene microarray. •475, 287 and 176 genes were differentially transcribed depending on temperature, Ni and Cd concentrations, respectively. •Genes involved in iron metabolism, transcriptional and translational processes, vitamin metabolism, blood coagulation, and calcium transport were impacted by metals. •The developed microarray contributes to a better characterization of the impact of different stressors on the transcriptome. -- Abstract: The molecular mechanisms underlying nickel (Ni) and cadmium (Cd) toxicity and their specific effects on fish are poorly understood. Documenting gene transcription profiles offers a powerful approach toward identifying the molecular mechanisms affected by these metals and to discover biomarkers of their toxicity. However, confounding environmental factors can complicate the interpretation of the results and the detection of biomarkers for fish captured in their natural environment. In the present study, a 1000 candidate-gene microarray, developed from a previous RNA-seq study on a subset of individual fish from contrasting level of metal contamination, was used to investigate the transcriptional response to metal (Ni and Cd) and non metal (temperature, oxygen, and diet) stressors in yellow perch (Perca flavescens). Specifically, we aimed at (1) identifying transcriptional signatures specific to Ni and Cd exposure, (2) investigating the mechanisms of their toxicity, and (3) developing a predictive tool to identify the sublethal effects of Ni and Cd contaminants in fish sampled from natural environments. A total of 475 genes displayed significantly different transcription levels when temperature varied while 287 and 176 genes were differentially transcribed at different concentrations of Ni and Cd, respectively. These metals were found to mainly affect the transcription level of genes

How does exposure to nickel and cadmium affect the transcriptome of yellow perch (Perca flavescens) – Results from a 1000 candidate-gene microarray

Energy Technology Data Exchange (ETDEWEB)

Bougas, Bérénice, E-mail: Berenice.Bougas@ete.inrs.ca [Institut National de la Recherche Scientifique, Centre INRS Eau Terre et Environnement, 490, rue de la Couronne, Québec, Québec G1K 9A9 (Canada); Département de biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec G1V 0A6 (Canada); Normandeau, Eric [Département de biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec G1V 0A6 (Canada); Pierron, Fabien [Université de Bordeaux, EPOC, UMR 5805, F-33400 Talence (France); CNRS, EPOC, UMR 5805, F-33400 Talence (France); Campbell, Peter G.C. [Institut National de la Recherche Scientifique, Centre INRS Eau Terre et Environnement, 490, rue de la Couronne, Québec, Québec G1K 9A9 (Canada); Bernatchez, Louis [Département de biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec G1V 0A6 (Canada); Couture, Patrice [Institut National de la Recherche Scientifique, Centre INRS Eau Terre et Environnement, 490, rue de la Couronne, Québec, Québec G1K 9A9 (Canada)

2013-10-15

Highlights: •The transcriptional responses of Perca flavescens to both metal and non metal stressors were measured with a 1000 candidate-gene microarray. •475, 287 and 176 genes were differentially transcribed depending on temperature, Ni and Cd concentrations, respectively. •Genes involved in iron metabolism, transcriptional and translational processes, vitamin metabolism, blood coagulation, and calcium transport were impacted by metals. •The developed microarray contributes to a better characterization of the impact of different stressors on the transcriptome. -- Abstract: The molecular mechanisms underlying nickel (Ni) and cadmium (Cd) toxicity and their specific effects on fish are poorly understood. Documenting gene transcription profiles offers a powerful approach toward identifying the molecular mechanisms affected by these metals and to discover biomarkers of their toxicity. However, confounding environmental factors can complicate the interpretation of the results and the detection of biomarkers for fish captured in their natural environment. In the present study, a 1000 candidate-gene microarray, developed from a previous RNA-seq study on a subset of individual fish from contrasting level of metal contamination, was used to investigate the transcriptional response to metal (Ni and Cd) and non metal (temperature, oxygen, and diet) stressors in yellow perch (Perca flavescens). Specifically, we aimed at (1) identifying transcriptional signatures specific to Ni and Cd exposure, (2) investigating the mechanisms of their toxicity, and (3) developing a predictive tool to identify the sublethal effects of Ni and Cd contaminants in fish sampled from natural environments. A total of 475 genes displayed significantly different transcription levels when temperature varied while 287 and 176 genes were differentially transcribed at different concentrations of Ni and Cd, respectively. These metals were found to mainly affect the transcription level of genes

Cadmium-handling strategies in two chronically exposed indigenous freshwater organisms-the yellow perch (Perca flavescens) and the floater mollusc (Pyganodon grandis)

International Nuclear Information System (INIS)

Campbell, Peter G.C.; Giguere, Anik; Bonneris, Emmanuelle; Hare, Landis

2005-01-01

Laboratory experiments on a variety of aquatic organisms suggest that metallothionein-like proteins (MT) play an important role in the regulation of essential metals, and in the sequestration and detoxification of non-essential metals (e.g., Cd). However, the importance of metallothionein production relative to alternative strategies of metal detoxification, and its effectiveness in metal detoxification, remain largely unexplored in field situations. In the present study we explored metal-handling strategies in an adult benthic bivalve (Pyganodon grandis) and in juvenile yellow perch (Perca flavescens), exposed to Cd in their natural habitat. The two biomonitor species were collected from lakes located along a Cd concentration gradient. Ambient dissolved Cd concentrations were determined by in situ dialysis as a measure of metal exposure. Sub-cellular Cd partitioning was determined in target tissues (bivalve gills and digestive gland; perch liver) by differential centrifugation, and metallothionein was measured independently by a mercury-saturation assay in the bivalve tissues. Malondialdehyde concentrations were measured as a potential indicator of oxidative stress. Ambient dissolved Cd concentrations ranged from 0.06 to 0.57 nM in the nine lakes from which bivalves were collected, and from max /[Cd] min ratios for the various tissues decreased in the order: bivalve gill Cd (28) > bivalve digestive gland Cd (18) > perch hepatic Cd (14). In the two lakes that were common to both the bivalve and perch studies, i.e. lakes Opasatica and Vaudray, accumulated Cd concentrations were consistently higher in the bivalve than in the perch. Cadmium-handling strategies were similar in the bivalve digestive gland and perch liver, in that Cd was mainly associated with the heat-stable protein (HSP) fraction. Furthermore, in these organs the contributions from the 'mitochondria' and 'lysosomes + microsomes' fractions were consistently higher than in the gill tissue. In the bivalve

Variation and accumulation patterns of poly- and perfluoroalkyl substances (PFAS) in European perch (Perca fluviatilis) across a gradient of pristine Swedish lakes.

Science.gov (United States)

Åkerblom, Staffan; Negm, Nesrin; Wu, Pianpian; Bishop, Kevin; Ahrens, Lutz

2017-12-01

This study assessed variations in the concentrations of poly- and perfluoroalkyl substances (PFAS) in European perch (Perca fluviatilis) in Swedish lakes and the extent to which fish size, age and indicators of fish trophic ecology (δ 15 N and δ 13 C) correlate with the sum of individual PFAS concentrations (ΣPFAS). Fish muscle tissue samples (n=80) were taken from six lakes across Sweden and analysed using solid-liquid extraction followed by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). PFAS levels in the lakes were affected by atmospheric deposition in relatively pristine areas with no direct point source of PFAS in the catchment. PFTeDA, PFUnDA, PFTriDA, PFDoDA, PFDA, PFOS and 6:2 FTSA were detected with a frequency between 68% and 99% and were included in the statistical evaluation. ΣPFAS differed between lakes (ANOVA: F=50.6, pPFAS, with a maximum ΣPFAS of 3.4ng g -1 wet weight (ww) (mean±SD: 0.99±0.63ng g -1 ww), while the lowest levels were found in lake Björntjärn (0.31±0.08ng g -1 ww) in northern Sweden (63°54'N, 18°51'E). PFOS was most abundant in perch from south-western Sweden, while other long-chain perfluorocarbons (>10 carbon atoms) were relatively more abundant in lakes in northern Sweden. Pearson correlation coefficients indicated that concentrations of PFAS in perch did not show any relation to fish size or age and were negatively correlated with trophic position of the fish (δ 15 N). It was also found that ΣPFAS were negatively correlated with both latitude and altitude. The PFAS data in this study represent national background concentrations in freshwater fish across Swedish lakes. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of two telemetry transmitter implantation incision suturing methods on the physiological state and condition of perch (Perca fluviatilis

Directory of Open Access Journals (Sweden)

Rożyński Maciej

2017-06-01

Full Text Available The aim of this work was to determine the impact on European perch, Perca fluviatilis L. (mean body weight – 78.33 g of the intraperitoneal implantation of telemetry transmitters using different suturing methods. In the first experiment silk sutures were used (experiment I – group ST, while in the second tissue adhesive was used (experiment II – group GT. Following the procedure, the fish were kept for 42 days in a recirculating system. Differences in growth and condition parameters were only noted in the first week of the experiment. Specimens from group GT had lower values for DGR (daily growth rate and SGR (specific growth rate, but a higher value for FCR (feed conversion ratio values. For the hematological parameters, lower values of MCV (mean corpuscular volume and PLT (blood platelets were noted in group GT, while for the biochemical parameters, lowered ALP (alkaline phosphatase activity and Mg (magnesium concentrations were noted in group ST. In group ST, 33.3% of the specimens loss their tags, while in group GT 77.8% did so. Differences in incision healing were only noted in the second week, when specimens in group ST were observed to have fully closed incisions, while in group GT 50% of the incisions were open. Despite the high percentage of implantation incision healing in both groups, because of the high values of tag loss rate, neither method can be recommended for perch. It might be more effective to use tag with external antennae in this species. The method use for closing implantation incisions also must be improved to eliminate tag shedding.

A multi-level biological approach to evaluate impacts of a major municipal effluent in wild St. Lawrence River yellow perch (Perca flavescens)

Energy Technology Data Exchange (ETDEWEB)

Houde, Magali, E-mail: magali.houde@ec.gc.ca [Centre Saint-Laurent, Environment Canada, 105 McGill Street, Montreal, QC H2Y 2E7 (Canada); Giraudo, Maeva, E-mail: maeva.giraudo@ec.gc.ca [Centre Saint-Laurent, Environment Canada, 105 McGill Street, Montreal, QC H2Y 2E7 (Canada); Douville, Mélanie, E-mail: melanie.douville@ec.gc.ca [Centre Saint-Laurent, Environment Canada, 105 McGill Street, Montreal, QC H2Y 2E7 (Canada); Bougas, Bérénice, E-mail: berenice.bougas.1@ulaval.ca [Institut de biologie intégrative et des systèmes, Université Laval, 1030, avenue de la Médecine, Québec, QC G1V 0A6 (Canada); Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC G1K 9A9 (Canada); Couture, Patrice, E-mail: patrice.couture@ete.inrs.ca [Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC G1K 9A9 (Canada); De Silva, Amila O., E-mail: amila.desilva@ec.gc.ca [Canada Centre for Inland Waters, Environment Canada, 867 Lakeshore Road, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada); Spencer, Christine, E-mail: christine.spencer@ec.gc.ca [Canada Centre for Inland Waters, Environment Canada, 867 Lakeshore Road, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada); Lair, Stéphane, E-mail: stephane.lair@umontreal.ca [Centre québécois sur la santé des animaux sauvages, Université de Montréal, C.P. 5000, St-Hyacinthe, QC J2S 7C6 (Canada); and others

2014-11-01

The development of integrated ecotoxicological approaches is of great interest in the investigation of global concerns such as impacts of municipal wastewater effluents on aquatic ecosystems. The objective of this study was to investigate the effects of a major wastewater municipal effluent on fish using a multi-level biological approach, from gene transcription and enzyme activities to histological changes. Yellow perch (Perca flavescens) were selected based on their wide distribution, their commercial and recreational importance, and the availability of a customized microarray. Yellow perch were sampled upstream of a major municipal wastewater treatment plant (WWTP) and 4 km and 10 km downstream from its point of discharge in the St. Lawrence River (Quebec, Canada). Concentrations of perfluoroalkyl substances (PFASs), polybrominated diphenyl ethers (PBDEs) and metals/trace elements in whole body homogenates were comparable to those from other industrialized regions of the world. Genomic results indicated that the transcription level of 177 genes was significantly different (p < 0.024) between exposed and non-exposed fish. Among these genes, 38 were found to be differentially transcribed at both downstream sites. Impacted genes were associated with biological processes and molecular functions such as immunity, detoxification, lipid metabolism/energy homeostasis (e.g., peroxisome proliferation), and retinol metabolism suggesting impact of WWTP on these systems. Moreover, antioxidant enzyme activities were more elevated in perch collected at the 4 km site. Biomarkers of lipid metabolism, biosynthetic activity, and aerobic capacities were significantly lower (p < 0.05) in fish residing near the outfall of the effluent. Histological examination of the liver indicated no differences between sites. Correlations between PFAS, PBDE, and metal/trace element tissue concentrations and markers of peroxisomal proliferation, oxidative stress, and retinoid metabolism were found

Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay

Energy Technology Data Exchange (ETDEWEB)

Blazer, Vicki S., E-mail: Vblazer@usgs.gov [U.S. Geological Survey, National Fish Health Research Laboratory, Leetown Science Center, 11649 Leetown Road, Kearneysville, WV 25430 (United States); Pinkney, Alfred E., E-mail: Fred_Pinkeny@fws.gov [U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, 177 Admiral Cochrane Drive, Annapolis, MD 21401 (United States); Jenkins, Jill A., E-mail: jenkinsj@usgs.gov [U.S. Geological Survey, National Wetlands Research Center, 700 Cajundome Blvd., Lafayette, LA 70506 (United States); Iwanowicz, Luke R., E-mail: Liwanowicz@usgs.gov [U.S. Geological Survey, National Fish Health Research Laboratory, Leetown Science Center, 11649 Leetown Road, Kearneysville, WV 25430 (United States); Minkkinen, Steven, E-mail: steve_minkkinen@fws.gov [U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, 177 Admiral Cochrane Drive, Annapolis, MD 21401 (United States); Draugelis-Dale, Rassa O., E-mail: daler@usgs.gov [U.S. Geological Survey, National Wetlands Research Center, 700 Cajundome Blvd., Lafayette, LA 70506 (United States); Uphoff, James H., E-mail: juphoff@dnr.state.md.us [Maryland Department of Natural Resources, Fisheries Service, Cooperative Oxford Laboratory, 904 South Morris Street, Oxford, MD 21654 (United States)

2013-03-01

Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007–2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed. - Highlights: ► Reduced recruitment of yellow perch has occurred in urban tributaries of Chesapeake Bay. ► We compared reproductive health biomarkers in perch from two urban, one developing, two less developed

Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay

International Nuclear Information System (INIS)

Blazer, Vicki S.; Pinkney, Alfred E.; Jenkins, Jill A.; Iwanowicz, Luke R.; Minkkinen, Steven; Draugelis-Dale, Rassa O.; Uphoff, James H.

2013-01-01

Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007–2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed. - Highlights: ► Reduced recruitment of yellow perch has occurred in urban tributaries of Chesapeake Bay. ► We compared reproductive health biomarkers in perch from two urban, one developing, two less developed watersheds. �

Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay

Science.gov (United States)

Blazer, Vicki; Pinkney, Alfred E.; Jenkins, Jill A.; Iwanowicz, Luke R.; Minkkinen, Steven; Draugelis-Dale, Rassa O.; Uphoff, James H.

2013-01-01

Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007–2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed.

Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay.

Science.gov (United States)

Blazer, Vicki S; Pinkney, Alfred E; Jenkins, Jill A; Iwanowicz, Luke R; Minkkinen, Steven; Draugelis-Dale, Rassa O; Uphoff, James H

2013-03-01

Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007-2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed. Published by Elsevier B.V.

Oviposition site selection and embryo mortality in perch

Czech Academy of Sciences Publication Activity Database

Smith, C.; Douglas, A.; Jurajda, Pavel

2001-01-01

Roč. 58, č. 3 (2001), s. 880-882 ISSN 0022-1112 Institutional research plan: CEZ:AV0Z6093917 Keywords : spawning * reproduction * Eurasian perch Subject RIV: EG - Zoology Impact factor: 1.249, year: 2001

A bacterial disease of yellow perch (Peres flavescens)

Science.gov (United States)

Ross, A.J.; Nordstrom, P.R.; Bailey, J.E.; Heaton, J.H.

1960-01-01

On May 26, 1959, two of the authors' investigated a fish kill at Dailey Lake, Park County, Montana. They observed about a half-dozen live, weakly swimming yellow perch (Perca flavescens), in addition to thousand of dead perch along the shoreline. It was learned from local residents that mortalities had begun to appear some 2 weeks earlier. At that time the time the authorities had diagnosed the condition as a winterkill, since ice had only recently disappeared from the lake. Although a number of other species inhabit Dailey Lake, including rainbow trout (Salmo gairdneri), brown trout (S. trutta), kokanee (Oncorhynchus nerka), black crappie (Pomoxis nigromaculatus), largemouth bass (Micropterus salmoides), longnose suckers (Catostomus catostomus), rainbow x cutthroat hybrids, only one other species was represented in the kill. This consisted of one black crappie.

Evaluating the spatial variation of total mercury in young-of-year yellow perch (Perca flavescens), surface water and upland soil for watershed-lake systems within the southern Boreal Shield

Science.gov (United States)

Gabriel, M.C.; Kolka, R.; Wickman, T.; Nater, E.; Woodruff, Laurel G.

2009-01-01

The primary objective of this research is to investigate relationships between mercury in upland soil, lake water and fish tissue and explore the cause for the observed spatial variation of THg in age one yellow perch (Perca flavescens) for ten lakes within the Superior National Forest. Spatial relationships between yellow perch THg tissue concentration and a total of 45 watershed and water chemistry parameters were evaluated for two separate years: 2005 and 2006. Results show agreement with other studies where watershed area, lake water pH, nutrient levels (specifically dissolved NO3−-N) and dissolved iron are important factors controlling and/or predicting fish THg level. Exceeding all was the strong dependence of yellow perch THg level on soil A-horizon THg and, in particular, soil O-horizon THg concentrations (Spearman ρ = 0.81). Soil B-horizon THg concentration was significantly correlated (Pearson r = 0.75) with lake water THg concentration. Lakes surrounded by a greater percentage of shrub wetlands (peatlands) had higher fish tissue THg levels, thus it is highly possible that these wetlands are main locations for mercury methylation. Stepwise regression was used to develop empirical models for the purpose of predicting the spatial variation in yellow perch THg over the studied region. The 2005 regression model demonstrates it is possible to obtain good prediction (up to 60% variance description) of resident yellow perch THg level using upland soil O-horizon THg as the only independent variable. The 2006 model shows even greater prediction (r2 = 0.73, with an overall 10 ng/g [tissue, wet weight] margin of error), using lake water dissolved iron and watershed area as the only model independent variables. The developed regression models in this study can help with interpreting THg concentrations in low trophic level fish species for untested lakes of the greater Superior National Forest and surrounding Boreal ecosystem.

Flow cytometric method for measuring chromatin fragmentation in fixed sperm from yellow perch (Perca flavescens).

Science.gov (United States)

Jenkins, J A; Draugelis-Dale, R O; Pinkney, A E; Iwanowicz, L R; Blazer, V S

2015-03-15

Declining harvests of yellow perch, Perca flavescens, in urbanized watersheds of Chesapeake Bay have prompted investigations of their reproductive fitness. The purpose of this study was to establish a flow cytometric technique for DNA analysis of fixed samples sent from the field to provide reliable gamete quality measurements. Similar to the sperm chromatin structure assay, measures were made on the susceptibility of nuclear DNA to acid-induced denaturation, but used fixed rather than live or thawed cells. Nuclei were best exposed to the acid treatment for 1 minute at 37 °C followed by the addition of cold (4 °C) propidium iodide staining solution before flow cytometry. The rationale for protocol development is presented graphically through cytograms. Field results collected in 2008 and 2009 revealed DNA fragmentation up to 14.5%. In 2008, DNA fragmentation from the more urbanized watersheds was significantly greater than from reference sites (P = 0.026) and in 2009, higher percentages of haploid testicular cells were noted from the less urbanized watersheds (P = 0.032) indicating better reproductive condition at sites with less urbanization. For both years, total and progressive live sperm motilities by computer-assisted sperm motion analysis ranged from 19.1% to 76.5%, being significantly higher at the less urbanized sites (P < 0.05). This flow cytometric method takes advantage of the propensity of fragmented DNA to be denatured under standard conditions, or 1 minute at 37 °C with 10% buffered formalin-fixed cells. The study of fixed sperm makes possible the restrospective investigation of germplasm fragmentation, spermatogenic ploidy patterns, and chromatin compaction levels from samples translocated over distance and time. The protocol provides an approach that can be modified for other species across taxa. Published by Elsevier Inc.

The use of artificial spawning substrates in order to understand the factors influencing the spawning site selection, depth of egg strands deposition and hatching time of perch (Perca fluviatilis L.

Directory of Open Access Journals (Sweden)

Jan Kubečka

2012-01-01

Full Text Available The distribution of egg strands of perch Perca fluviatilis and factors affecting this distribution, in terms of spawning sites and spawning depths used, was studied in spring 2010 in Chabařovice Lake, Czech Republic, using areas with an artificial spawning substrate (A.S.S. and control areas outside the A.S.S. Perch significantly preferred a calm shore instead of a windward shore for spawning. The depths at which perch egg strands were found increased significantly during the spawning period in both A.S.S. areas and in areas outside the A.S.S. (on average from 4.9 m at the beginning to 12.3 m at the end of the spawning period. With increasing depth of deposition the size of the egg strands decreased significantly. The mean depth of egg strands on individual dates corresponded to the position of 10-12°C water layers. From the third week onward, however, egg strands were deposited in much deeper and colder water. A strong relationship was found between the depth at which egg strands were deposited and the duration of the daylight period, indicating that, at the end of the spawning season, perch do not react to the actual temperature of the water column but that they follow their inner clock, assuming that "normally" the shallower depth layers are too warm for successful embryo development. Factors influencing the depth distribution of egg strands were identified as waves, temperature and duration of the daylight period. Factors influencing the selection of spawning sites were identified as wind inducing current, internal seiches and temperature instability of the water column. The first perch larvae were present in the open water of Chabařovice Lake before mid-May, and the latest larvae not earlier than the beginning of July, since warming of the water in deeper layers was very slow. It appears that with prolonged spawning and hatching periods and with spawning occurring at various depths and temperatures, perch have evolved a powerful

Gonad development and plasma steroid profiles by HRGC/HRMS during one reproductive cycle in reference and leachate-exposed female perch (Perca fluviatilis)

International Nuclear Information System (INIS)

Noaksson, Erik; Gustavsson, Bodil; Linderoth, Maria; Zebuehr, Yngve; Broman, Dag; Balk, Lennart

2004-01-01

Endocrine processes were studied in reference female perch (Perca fluviatilis) from Lake Djursjoen and in leachate-exposed females from Lake Molnbyggen during one reproductive cycle. A high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) technique enabled the analysis of circulating sex steroids [progesterone (P), 17α-hydroxyprogesterone (17α-OHP), androstenedione (A), testosterone (T), estrone (E1), and 17β-estradiol (E2)], the maturation-inducing hormone (MIH) 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-P), and glucocorticoids [11-deoxycortisol (11-DC) and cortisol]. Body and organ measurements, ratio of sexually mature (SM) females, and frequencies of body lesions, were also recorded. High frequencies of body lesions and a low ratio of SM females were generally found in Molnbyggen. These females also had lower gonadosomatic index (GSI) and liver-somatic index (LSI) in the early stages of vitellogenesis, indicating either a delayed onset of oogenesis or an impaired vitellogenesis. Non-reproducing females from both lakes showed a similar LSI cycle as SM females. Increasing T and A levels in SM females from Djursjoen coincided with the GSI peak at the time of spawning. These two androgens were on several occasions lower in SM females from Molnbyggen, possibly the result of a disrupted 17,20-lyase activity of the P450 17α enzyme because only minor effects were observed on circulating P and 17α-OHP levels. E2 and E1 levels increased during vitellogenesis in females from both lakes, with E1 levels more closely resembling the peaks of A and GSI. Peak levels of 17α,20β-P at the time of spawning confirmed its function as the MIH in perch, while the simultaneous peak of 11-DC suggests that it also may be involved in final maturation of the oocytes

Feeding under predation risk: potential sex-specific response of perch (Perca fluviatilis).

Czech Academy of Sciences Publication Activity Database

Estlander, Satu; Nurminen, L.

2014-01-01

Roč. 23, č. 3 (2014), s. 478-480 ISSN 0906-6691 Institutional support: RVO:60077344 Keywords : foraging * sexual size dimorphism * predation * perch * pike Subject RIV: EH - Ecology, Behaviour Impact factor: 1.701, year: 2014

Enzymatic correlates of energy status in wild yellow perch inhabiting clean and contaminated environments.

Science.gov (United States)

Gauthier, Charles; Campbell, Peter G C; Couture, Patrice

2011-09-01

Enzymes representing a variety of metabolic pathways were examined in yellow perch (Perca flavescens) collected from a metal-contaminated region (Rouyn-Noranda, Québec, Canada) to determine which were most closely related to fish condition factor, pyloric caeca weight, and visceral lipid accumulation, as well to seek a better understanding of the influence of metal contamination on the physiology and biometrics of perch. Compared to laboratory fish, wild perch were under important energy restrictions. The condition factor of wild fish was correlated with indicators of aerobic metabolism (citrate synthase, cytochrome C oxidase), protein anabolism (nucleoside diphosphokinase), and indicators of lipid accumulation (glucose-6-phosphate dehydrogenase, visceral lipid index). Pyloric caeca weights were well correlated with indicators of protein anabolism, but only when both seasons were examined together, possibly indicating a lag in the response of enzymes to changes in diet. The addition of contaminant stress to existing energy restrictions led to changes in the relationships between enzymes and biometrics, reducing the predictive power of the models for perch in contaminated lakes. The present study broadens our knowledge of the impact of metal contamination on energy accumulation and tissue metabolic capacities in wild perch. Copyright © 2011 SETAC.

Sampling of deep benthic perch fry: insight into the diel vertical migrations.

Czech Academy of Sciences Publication Activity Database

Čech, Martin; Frouzová, Jaroslava; Peterka, Jiří; Jůza, Tomáš; Draštík, Vladislav; Vašek, Mojmír; Kubečka, Jan

2017-01-01

Roč. 784, č. 1 (2017), s. 1-8 ISSN 0018-8158 R&D Projects: GA ČR GA206/06/1371; GA ČR GP206/09/P266; GA MŠk(CZ) EE2.3.20.0204; GA MŠk(CZ) 7F14316 Institutional support: RVO:60077344 Keywords : bathypelagic perch fry * Breder trap * Fulton's condition factor * Perca fluviatilis * Římov Reservoir * SCUBA diving Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 2.056, year: 2016

Food selectivity of perch (Perca fluviatilis L. ) in acidified lakes on the west coast of Sweden

Energy Technology Data Exchange (ETDEWEB)

Andersson, B

1972-01-01

The objective of the present paper was to examine presumed changes in the food composition of perch in lakes subjected to recent acidification, which emanates from sulfuric acid in the precipitation. The material analyzed (825 preserved specimens from 49 different lakes) was collected by the Fishery Board. These lakes represent a great variability in terms of pH. The perch were divided into four size groups and the stomach contents of each specimen was analyzed qualitatively and quantitatively. The results indicate that fish, which make up the bulk of food for adult perch, are replaced by various invertebrates at a decreasing pH. With a moderate decrease the water hog-louse (Asellus aquaticus) appears of major importance, whereas its place is taken by Corixa bugs in the most acidified lakes. These latter invertebrates are normally absent in the food of adult perch. Also, plankton accounts for a substantial share of the stomach contents. The reasons for these changes are manifold, but two factors are primarily discussed in this paper, viz. the effect of the acidification on the prey populations and the elimination of certain species by selective predation in a normal lake.

Susceptibility of Koi and Yellow Perch to infectious hematopoietic necrosis virus by experimental exposure

Science.gov (United States)

Palmer, Alexander D.; Emmenegger, Eveline J.

2014-01-01

Infectious hematopoietic necrosis virus (IHNV) is a novirhabdoviral pathogen that originated in western North America among anadromous Pacific salmonids. Severe disease epidemics in the late 1970s resulting from IHNV's invasion into farmed Rainbow Trout Oncorhynchus mykiss in North America, Asia, and Europe emphasized IHNV's ability to adapt to new hosts under varying rearing conditions. Yellow Perch Perca flavescens and Koi Carp Cyprinus carpio (hereafter, “Koi”) are aquaculture-reared fish that are highly valued in sport fisheries and the ornamental fish trade, respectively, but it is unknown whether these fish species are vulnerable to IHNV infection. In this study, we exposed Yellow Perch, Koi, and steelhead (anadromous Rainbow Trout) to IHNV by intraperitoneal injection (106 PFU/fish) and by immersion (5.7×105 PFU/mL) for 7 h, and monitored fish for 28 d. The extended immersion exposure and high virus concentrations used in the challenges were to determine if the tested fish had any level of susceptibility. After experimental exposure, Yellow Perch and Koi experienced low mortality (35%). Virus was found in dead fish of all species tested and in surviving Yellow Perch by plaque assay and quantitative reverse transcription polymerase chain reaction (qPCR), with a higher prevalence in Yellow Perch than Koi. Infectious virus was also detected in Yellow Perch out to 5 d after bath challenge. These findings indicate that Yellow Perch and Koi are highly resistant to IHNV disease under the conditions tested, but Yellow Perch are susceptible to infection and may serve as possible virus carriers.

Genetic diversity of perch rhabdoviruses isolates based on the nucleoprotein and glycoprotein genes.

Science.gov (United States)

Talbi, Chiraz; Cabon, Joelle; Baud, Marine; Bourjaily, Maya; de Boisséson, Claire; Castric, Jeannette; Bigarré, Laurent

2011-12-01

Despite the increasing impact of rhabdoviruses in European percid farming, the diversity of the viral populations is still poorly investigated. To address this issue, we sequenced the partial nucleoprotein (N) and complete glycoprotein (G) genes of nine rhabdoviruses isolated from perch (Perca fluviatilis) between 1999 and 2010, mostly from France, and analyzed six of them by immunofluorescence antibody test (IFAT). Using two rabbit antisera raised against either the reference perch rhabdovirus (PRhV) isolated in 1980 or the perch isolate R6146, two serogroups were distinguished. Meanwhile, based on partial N and complete G gene analysis, perch rhabdoviruses were divided into four genogroups, A-B-D and E, with a maximum of 32.9% divergence (G gene) between isolates. A comparison of the G amino acid sequences of isolates from the two identified serogroups revealed several variable regions that might account for antigenic differences. Comparative analysis of perch isolates with other rhabdoviruses isolated from black bass, pike-perch and pike showed some strong phylogenetic relationships, suggesting cross-host transmission. Similarly, striking genetic similarities were shown between perch rhabdoviruses and isolates from other European countries and various ecological niches, most likely reflecting the circulation of viruses through fish trade as well as putative transfers from marine to freshwater fish. Phylogenetic relationships of the newly characterized viruses were also determined within the family Rhabdoviridae. The analysis revealed a genetic cluster containing only fish viruses, including all rhabdoviruses from perch, as well as siniperca chuatsi rhabdovirus (SCRV) and eel virus X (EVEX). This cluster was distinct from the one represented by spring viraemia of carp vesiculovirus (SVCV), pike fry rhabdovirus (PFRV) and mammalian vesiculoviruses. The new genetic data provided in the present study shed light on the diversity of rhabdoviruses infecting perch in

The diet of reservoir perch before, during and after establishment of non-native tubenose goby

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Všetičková Lucie

2018-01-01

Full Text Available In recent decades, gobiid species have increased their distribution throughout Europe and now often represent the dominant genus along many rivers and canals. In this study, we assessed the role of tubenose goby (Proterorhinus semilunaris as a prey species of native perch (Perca fluviatilis in a lowland reservoir soon after their initial introduction in 1994 (sampling started 1998 and 17 years after establishment (2011–2012. We compare these data with perch diet composition from before introduction (1981–1982. Our data indicate that tubenose gobies quickly became the dominant species along the reservoir bankside, making them an attractive prey for ≥1 + perch. There was a clear increasing trend in the numbers of larger perch caught along the rip-rap, with the largest fish clearly specialising on gobies. As such, introduction of tubenose gobies has had a pronounced effect on food web and population dynamics along the littoral zone. While goby numbers appear to have dropped significantly in recent years, apparently due to predation pressure, further studies are needed to assess whether such changes have had any general impact on population and food web dynamics within the reservoir.

Comparative analysis of the shape of the perch from Techa river and Miass river

Energy Technology Data Exchange (ETDEWEB)

Osipov, D.; Pryakhin, E. [Urals Research Center for Radiation Medicine - URCRM (Russian Federation); Rudolfsen, G. [Norwegian Radiation Protection Authority (NRPA) and University of Tromsoe (Norway); Yegoreichenkov, E. [Urals Research Center for Radiation Medicine (Russian Federation)

2014-07-01

The adaptation to environmental conditions can be accompanied by morphological changes. Description of morphological differences in animal populations could reveal differences habitat, both abiotic and biotic factors. In our study we examined if fish habituating river with different activity concentration of radionuclides differ in geometric morphometry. Geometric morphometry makes it possible to identify morphological differences between objects on the basis of the form, without influence of the 'size factor'. The approach is based on a multivariate analysis of the coordinates of marks, placed on the surface of the morphological object in accordance with certain rules. We used perch (Perca fluviatilis Linnaeus, 1758) as a study species as it is a common, and widespread species of freshwater fish in moderate and subarctic latitudes of Eurasia and North America. Perch is characterized by high flexibility of morphology in relation to environmental differences. We investigated body shape and its changes with the growth in perch that live in Techa River under chronic radiation exposure and perch in the control river Miass. The alignment of digital image tags that characterize the shape of the fish's body, was implemented in the program TPSdig. Further analysis was performed using the package geomorph for R statistical software. The study showed statistically significant (F{sub 1,95}=12.69, p=0.01) differences in body shape of perch from Techa river and Miass river. Perch living in the Techa River are relatively shorter and higher. Further, perch in Techa is characterized by a smaller size of the eyes. For both populations the contribution of allometric component to shape change was observed: smaller animals have a shape similar to the Miass river perch population. With increase of body size, shape of the perch becomes similar to that of the Techa's perch population. Significant differences were observed only for young animals from the two rivers

Live transport of Yellow Perch and Nile Tilapia in AQUI-S 20E (10% Eugenol) at high loading densities

Science.gov (United States)

Cupp, Aaron R.; Schreier, Theresa M.; Schleis, Sue M.

2017-01-01

Fish transport costs are a substantial portion of the operational expenses for aquaculture facilities in the USA. Safely transporting higher loading densities of fish would benefit haulers by increasing efficiency and reducing costs, but research evaluating transport for individual species is generally lacking. In this study, Yellow Perch Perca flavescens and Nile Tilapia Oreochromis niloticus were transported for 6 h immersed in water containing AQUI-S 20E (10% eugenol) at fish loading densities of 240 g/L (2 lb/gal) for perch and 480 g/L (4 lb/gal) for tilapia. Survival was quantified for fish transported in AQUI-S 20E concentrations of (1) control or 0 mg/L of water, (2) 100 mg/L, or (3) 200 mg/L. Yellow Perch had 98–100% survival, and Nile Tilapia had 100% survival up to through 14 d after transport across all AQUI-S 20E levels, including the control. Eugenol concentrations decreased rapidly in transport tank water, and fish showed no signs of sedation by the end of transport. We conclude that live transport of Yellow Perch and Nile Tilapia at higher loading densities resulted in high survival regardless of the AQUI-S 20E concentrations we tested.

Impairment of metabolic capacities in copper and cadmium contaminated wild yellow perch (Perca flavescens)

International Nuclear Information System (INIS)

Couture, Patrice; Rajender Kumar, Puja

2003-01-01

This study examined variations in resting oxygen consumption rate (ROCR), post-exercise oxygen consumption rate, relative scope for activity (RSA), liver and muscle aerobic and anaerobic capacities (using citrate synthase (CS) and lactate dehydrogenase, respectively, as indicators), and tissue biosynthetic capacities (using nucleoside diphosphate kinase (NDPK) as an indicator), in wild yellow perch from four lakes varying in copper (Cu) and cadmium (Cd) contamination. Liver Cu and Cd concentrations largely reflected environmental contamination and were positively correlated with liver protein concentrations and NDPK activities. Our results suggest that metal contamination leads to an upregulation of liver protein metabolism, presumably at least in part for the purpose of metal detoxification. In contrast, muscle NDPK activities decreased with increasing liver Cd concentrations and NDPK activities. There was a 25% decrease in ROCR for a doubling of liver Cu concentrations and a 42% decrease in RSA for a doubling of liver Cd concentrations in the range studied. Cu contamination was also associated with lower muscle CS activities. Our results support previous findings of impaired aerobic capacities in the muscle of metal-contaminated fish, and demonstrate that this impairment is also reflected in aerobic capacities of whole fish. The evidence presented suggests that mitochondria may be primary targets for inhibition by Cu, and that Cd may reduce gill respiratory capacity. Muscle aerobic and anaerobic capacities were inversely related. This work indicates that metal exposure of wild yellow perch leads to a wide range of disturbances in metabolic capacities

Differential tolerance to cyanobacterial exposure between geographically distinct populations of Perca fluviatilis.

Science.gov (United States)

Persson, Karl-Johan; Bergström, Kristofer; Mazur-Marzec, Hannah; Legrand, Catherine

2013-12-15

Toxic cyanobacterial blooms are an important problem worldwide. Cyanobacteria may negatively impact young-of-the-year (YOY) fish directly (toxin production, turbidity, decrease in water quality) or indirectly (trophic toxin transfer, changes in prey species composition). Here we test whether there are any differences in cyanobacterial tolerance between four geographically distinct populations of European perch (Perca fluviatilis). We show that P. fluviatilis may develop tolerance against cyanobacteria demonstrated by the ability of individuals from a marine site (exposed to annual cyanobacterial blooms) to increase their detoxification more than individuals from an oligotrophic site (rarely exposed to cyanobacteria). Our results also revealed significant interaction effects between genotypes within a population and response to cyanobacterial exposure in terms of absolute growth and detoxification activity. This genotype by treatment interaction may result in local adaptations to cyanobacterial exposure in P. fluviatilis. Hence, the sensitivity against cyanobacterial exposure may differ between within species populations increasing the importance of local management of fish populations. Copyright © 2013 Elsevier Ltd. All rights reserved.

A COMPARATIVE STUDY ON THE FEEDING COMPETITION OF THE EUROPEAN PERCH PERCA FLUVIATILIS L. AND THE RUFFE GYMNOCEPHALUS CERNUUS (L. IN LAKE PIEDILUCO (UMBRIA, ITALY.

Directory of Open Access Journals (Sweden)

LORENZONI M.

2007-10-01

Full Text Available The abundance of European perch in Lake Piediluco has significantly dwindled in the last few years. The present study on diet overlap between perch and ruffe was prompted by the rapid expansion of the ruffe stock in the lake. This species was first found in the lake in 1996 and has since become one of the most abundant. The degree of diet overlap between the two species was analyzed by using data on the stomach contents of 275 European perch and 328 ruffe. Results are expressed as abundance (%N, occurrence (%S, weight percentage (%W and index of predominance (Ip. The diet overlap index (α was calculated by means of Schoener’s formula using the %W of each food item. As an estimate of the diet width of both species, we used Levins’ indexes of niche breadth (B and standardized measurement of niche breadth (BA. Both species are strictly carnivorous, feeding mainly on invertebrates: the most important diet components were dipterans and crustaceans, but the European perch also feeds on fish. In the perch, the Levins index was greater (B=4.332 than that calculated for the ruffe (B=2.262. During the ontogenesis of the European perch, there is a rather pronounced diet shift: dipterans form the largest portion of the diet at all ages, though in older perch fish-eating becomes increasingly evident. Benthic crustaceans tend to be consumed in greater quantities by the 3+ age-class, though they are also found in the stomachs of specimens of all ages. Ruffe, by contrast, do not display a pronounced ontogenetic diet shift. The index of diet overlap between the two species was rather high, the maximum α value being 0.853; values indicate a high degree of diet overlap in the younger ageclasses (1+, 2+ and 3+, with a greater differentiation between the diets of the two species emerging as the age of the perch increased. Our research also clarified some of the biological characteristics of the European perch in Lake Piediluco, namely, theoretical growth in

Impact of different colours of artificial light at night on melatonin rhythm and gene expression of gonadotropins in European perch.

Science.gov (United States)

Brüning, Anika; Hölker, Franz; Franke, Steffen; Kleiner, Wibke; Kloas, Werner

2016-02-01

The distribution and intensity of artificial light at night, commonly referred to as light pollution, is consequently rising and progressively also ecological implications come to light. Low intensity light is known to suppress nocturnal melatonin production in several fish species. This study aims to examine the least suppressive light colour for melatonin excreted into the holding water and the influence of different light qualities and quantities in the night on gene expression of gonadotropins in fish. European perch (Perca fluviatilis) were exposed to light of different wavelengths during the night (blue, green, and red). Melatonin concentrations were measured from water samples every 3h during a 24h period. Gene expression of gonadotropins was measured in perch exposed to different light colours and was additionally examined for perch subjected to different intensities of white light (0 lx, 1 lx, 10 lx, 100 lx) during the night. All different light colours caused a significant drop of melatonin concentration; however, blue light was least suppressive. Gene expression of gonadotropins was not influenced by nocturnal light of different light colours, but in female perch gonadotropin expression was significantly reduced by white light already at the lowest level (1 lx). We conclude that artificial light with shorter wavelengths at night is less effective in disturbing biological rhythms of perch than longer wavelengths, coinciding with the light situation in freshwater habitats inhabited by perch. Different light colours in the night showed no significant effect on gonadotropin expression, but white light in the night can disturb reproductive traits already at very low light intensities. These findings indicate that light pollution has not only the potential to disturb the melatonin cycle but also the reproductive rhythm and may therefore have implications on whole species communities. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of predation stress and food ration on perch gut microbiota.

Science.gov (United States)

Zha, Yinghua; Eiler, Alexander; Johansson, Frank; Svanbäck, Richard

2018-02-06

Gut microbiota provide functions of importance to influence hosts' food digestion, metabolism, and protection against pathogens. Factors that affect the composition and functions of gut microbial communities are well studied in humans and other animals; however, we have limited knowledge of how natural food web factors such as stress from predators and food resource rations could affect hosts' gut microbiota and how it interacts with host sex. In this study, we designed a two-factorial experiment exposing perch (Perca fluviatilis) to a predator (pike, Esox lucius), and different food ratios, to examine the compositional and functional changes of perch gut microbiota based on 16S rRNA amplicon sequencing. We also investigated if those changes are host sex dependent. We showed that overall gut microbiota composition among individual perch significantly responded to food ration and predator presence. We found that species richness decreased with predator presence, and we identified 23 taxa from a diverse set of phyla that were over-represented when a predator was present. For example, Fusobacteria increased both at the lowest food ration and at predation stress conditions, suggesting that Fusobacteria are favored by stressful situations for the host. In concordance, both food ration and predation stress seemed to influence the metabolic repertoire of the gut microbiota, such as biosynthesis of other secondary metabolites, metabolism of cofactors, and vitamins. In addition, the identified interaction between food ration and sex emphasizes sex-specific responses to diet quantity in gut microbiota. Collectively, our findings emphasize an alternative state in gut microbiota with responses to changes in natural food webs depending on host sex. The obtained knowledge from this study provided us with an important perspective on gut microbiota in a food web context.

Activity and food choice of piscivorous perch ( Perca fluviatilis ) in a eutrophic shallow lake: a radio-telemetry study

DEFF Research Database (Denmark)

Jacobsen, Lene; Berg, Søren; Broberg, M.

2002-01-01

in midsummer. The general lack of activity at night supports the idea that perch is a visually oriented forager. 4. There was no significant relationship between daytime activity during the year and temperature or day length, but nighttime activity was correlated with temperature. In contrast with previous......+ planktivorous fish in lakes and has potential implications for pelagic food web structure and lake management by biomanipulation...

The effect of salinity on resting metabolism in Eurasian perch (Perca fluviathlis L.)

DEFF Research Database (Denmark)

Ern, R.; Cong, N.; Houng, D.

2008-01-01

to properly maintain ion balance even with minor increases in the environmental salinity. The elevated resting VO2 in 10 ppt is equivalent to an increased energy consumption of 975 extra calories per day, and since food intake was unaffected, it is reasonable to assume that the reduced growth seen...... in a freshwater population of P. fluviatilis. Food intake was unaffected and we, therefore, measured resting oxygen uptake (VO2) in fish maintained for 21 days in either fresh or brackish (10 ppt) water using intermittent closed respirometry. VO2 of all fish reached stable levels within 5 h of entering...

Effects of habitat type on short- and long-term growth parameters of the European perch (Perca fluviatilis L.)

Czech Academy of Sciences Publication Activity Database

Petrtýl, M.; Kalous, L.; Frouzová, Jaroslava; Čech, Martin

2015-01-01

Roč. 100, č. 1 (2015), s. 13-20 ISSN 1434-2944 R&D Projects: GA ČR(CZ) GA206/06/1371; GA ČR(CZ) GP206/09/P266; GA MŠk(CZ) EE2.3.20.0204 Institutional support: RVO:60077344 Keywords : diel vertical migrations * RNA/DNA ratio * bathypelagic perch fry * growth rate * fish larvae * Římov Reservoir Subject RIV: GL - Fishing Impact factor: 1.459, year: 2015

Adaptive major histocompatibility complex (MHC) and neutral genetic variation in two native Baltic Sea fishes (perch Perca fluviatilis and zander Sander lucioperca) with comparisons to an introduced and disease susceptible population in Australia (P. fluviatilis): assessing the risk of disease epidemics.

Science.gov (United States)

Faulks, L K; Östman, Ö

2016-04-01

This study assessed the major histocompatibility complex (MHC) and neutral genetic variation and structure in two percid species, perch Perca fluviatilis and zander Sander lucioperca, in a unique brackish ecosystem, the Baltic Sea. In addition, to assess the importance of MHC diversity to disease susceptibility in these populations, comparisons were made to an introduced, disease susceptible, P. fluviatilis population in Australia. Eighty-three MHC class II B exon 2 variants were amplified: 71 variants from 92 P. fluviatilis samples, and 12 variants from 82 S. lucioperca samples. Microsatellite and MHC data revealed strong spatial genetic structure in S. lucioperca, but not P. fluviatilis, across the Baltic Sea. Both microsatellite and MHC data showed higher levels of genetic diversity in P. fluviatilis from the Baltic Sea compared to Australia, which may have facilitated the spread of an endemic virus, EHNV in the Australian population. The relatively high levels of genetic variation in the Baltic Sea populations, together with spatial genetic structure, however, suggest that there currently seems to be little risk of disease epidemics in this system. To ensure this remains the case in the face of ongoing environmental changes, fisheries and habitat disturbance, the conservation of local-scale genetic variation is recommended. © 2016 The Fisheries Society of the British Isles.

Perch and Its Parasites as Heavy Metal Biomonitors in a Freshwater Environment: The Case Study of the Ružín Water Reservoir, Slovakia

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Dana Miklisová

2012-03-01

Full Text Available Heavy metal concentrations were determined in 43 perches (Perca fluviatilis and in two of its most common parasites, the acanthocephalan Acanthocephalus lucii and the cestode Proteocephalus percae, collected in the period 2009–2010 from Ružín, a seriously polluted water reservoir in Slovakia. Samples of muscle, liver, kidney, brain, male and female reproductive organs and adipose tissue of fish and both parasites were analyzed for As, Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn, by ICP-MS. Mean concentrations of individual heavy metals in all fish samples decreased in the order zinc > copper > manganese > mercury > arsenic > chromium > cadmium > nickel > lead. Zinc was found to be the dominant element and its antagonistic interaction with copper was confirmed. The kidney was a key target organ receiving the highest mean concentrations of all analyzed metals, but some metals showed specific affinity for particular tissues. In terms of human health, concentration of Hg in fish muscle, which exceeded more than two-times its maximum level admitted in foodstuffs in European countries, is of great importance and should be taken into account. Bioaccumulation factors (C[parasite]/C[fish tissue] calculated for all elements indicated much higher detection skills of A. lucii and P. percae parasites than fish organs and hence, present results allow proposing both parasite models as useful tools to monitor aquatic environmental quality. Acanthocephalans, however, seem to be superior for heavy metal monitoring, also demonstrated under experimental conditions. Present results also indicate the decreasing heavy metal burden of the reservoir and its gradual recovery in the course of time.

On the suitability of roach, perch, vendace and whitefish for canning in small scale canning stations

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Mailis Kuuppo

1978-07-01

Full Text Available The suitability of roach (Rutilus rutilus, perch (Perca fluviatilis, vendace (Coregonus albula L., and whitefish (Coregonus sp. for canning in small scale canning stations was tested. Various pretreatment methods and processing conditions were evaluated for different fish species. Processing equipment suitable for small scale canning stations was developed in the course of this study. The keepability of the canned products was followed by physical, organoleptic and microbiological determinations during a period of 18 months. The roach, vendace and whitefish preserves were of the types »canned fish in tomato sauce» and »canned fish in oil and its own juice» and the perch preserves of the type »canned fish in brine». Roach, vendace and whitefish were salted by immersing into 21 % brine for 4—25 minutes depending on the size of the fish and preheated by smoking at 90° C for 60 —120 minutes. Products of good quality were obtained from whitefish which was dried by cooking in oil at 120 °C for 3 minutes instead of smoking. The perch were cooked in 3 % and 4 % brine for 15—20 minutes depending on the size of the fish. The best time and temperature combination for the aimed F value 10 and for a product of good quality was 60 minutes at 115°C when using rotation. In organoleptic evaluation all the canned products were judged to be of good quality and there were no significant changes in appearance, texture, taste or aroma during 18 months' storage at room temperature. No microbial growth or swelling of the cans was detected during storage. Use of frozen raw material in canning whitefish had no detectable effect on the quality of the final product.

Yellow perch larval survival in the Zekiah Swamp watershed (Wicomico River, Maryland) relative to the potential effects of a coal ash storage facility

International Nuclear Information System (INIS)

Burton, W.H.; Pinkney, A.E.

1994-01-01

A coordinated program of in situ and laboratory bioassays supported by water quality analyses was used to evaluate the potential effect of a coal ash storage facility on a yellow perch (Perca flavescens) spawning area. The facility is located in the Zekiah Swamp watershed, a tributary of the Wicomico River, MD. In situ bioassays were conducted in Zekiah Swamp Run and reference locations in 1989 and 1990. Larval mortality was high in non-tidal areas of Zekiah Swamp Run, both at a site upstream and beyond the influence of the facility, and at a site downstream of the facility. Mortality was significantly less at a nearby reference stream and at a station in the tidal area of Zekiah Swamp Run. Analysis of water samples for metals (including inorganic monomeric aluminum), organic contaminants, and pH, as well as measurements of stream flow, did not identify a specific cause for the mortality. The field and laboratory bioassays showed that, although leachate from the ash facility contributed to local contamination of ground water, the facility does not appear to be responsible for the poor survival of larval yellow perch. 16 refs., 4 figs., 6 tabs

Combined effects of temperature changes and metal contamination at different levels of biological organization in yellow perch

International Nuclear Information System (INIS)

Grasset, Julie; Ollivier, Élodie; Bougas, Bérénice; Yannic, Glenn; Campbell, Peter G.C.; Bernatchez, Louis; Couture, Patrice

2016-01-01

Highlights: • Yellow perch were exposed to a combination of heat and metal (Cd or Ni) stress. • Kidney metal accumulation was greatly enhanced at higher temperatures. • Elevated temperatures negatively affected several indicators of condition and metabolic capacities. • Exposure to Ni stimulated gonad development. • Metal stress modified the normal response of antioxidant capacities and apoptosis to heat stress. - Abstract: In this study, we measured the effects of temperature (9 °C, 20 °C, and 28 °C), metal contamination (cadmium and nickel) and their interaction on yellow perch (Perca flavescens) using liver enzymatic and transcriptomic endpoints and biometric indices. Kidney metal concentrations increased with a rise of temperature. The biometric indices analysed (Fulton condition factor, pyloric cæca, hepatosomatic and gonadosomatic indices) generally decreased with an increase of temperature but not with metal contamination. At the enzymatic level, the activity of superoxide dismutase (SOD), involved in antioxidant response, was affected by both temperature and metal contamination, whereas the activity of glucose-6-phosphate dehydrogenase (G6PDH), involved in energy accumulation but also in antioxidant response, was only affected by metal exposure. The response of perch to the stressors at the transcriptional level differed from the metabolic response. In particular, the transcription level of the cco and g6pdh genes sharply decreased with increasing temperature, while the activities of the corresponding enzymes remained stable. The normal response of the transcription level of the apoptotic gene (diablo) to heat stress was also altered in metal-contaminated fish. The combination of metal and temperature stresses also modified the response of antioxidant metabolism induced by these stressors individually. This study contributes to a better understanding of the influences of natural stressors like temperature on biomarkers commonly used in

Combined effects of temperature changes and metal contamination at different levels of biological organization in yellow perch

Energy Technology Data Exchange (ETDEWEB)

Grasset, Julie [Institut National de la Recherche Scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC G1K 9A9 (Canada); Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, QC G1V 0A6 (Canada); Ollivier, Élodie [Institut National de la Recherche Scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC G1K 9A9 (Canada); Bougas, Bérénice [Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, QC G1V 0A6 (Canada); Yannic, Glenn [Laboratoire d’Écologie Alpine, UMR CNRS 5553, Université de Savoie Mont Blanc, 73376 Le Bourget-du-lac (France); Campbell, Peter G.C. [Institut National de la Recherche Scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC G1K 9A9 (Canada); Bernatchez, Louis [Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, QC G1V 0A6 (Canada); Couture, Patrice, E-mail: patrice.couture@ete.inrs.ca [Institut National de la Recherche Scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC G1K 9A9 (Canada)

2016-08-15

Highlights: • Yellow perch were exposed to a combination of heat and metal (Cd or Ni) stress. • Kidney metal accumulation was greatly enhanced at higher temperatures. • Elevated temperatures negatively affected several indicators of condition and metabolic capacities. • Exposure to Ni stimulated gonad development. • Metal stress modified the normal response of antioxidant capacities and apoptosis to heat stress. - Abstract: In this study, we measured the effects of temperature (9 °C, 20 °C, and 28 °C), metal contamination (cadmium and nickel) and their interaction on yellow perch (Perca flavescens) using liver enzymatic and transcriptomic endpoints and biometric indices. Kidney metal concentrations increased with a rise of temperature. The biometric indices analysed (Fulton condition factor, pyloric cæca, hepatosomatic and gonadosomatic indices) generally decreased with an increase of temperature but not with metal contamination. At the enzymatic level, the activity of superoxide dismutase (SOD), involved in antioxidant response, was affected by both temperature and metal contamination, whereas the activity of glucose-6-phosphate dehydrogenase (G6PDH), involved in energy accumulation but also in antioxidant response, was only affected by metal exposure. The response of perch to the stressors at the transcriptional level differed from the metabolic response. In particular, the transcription level of the cco and g6pdh genes sharply decreased with increasing temperature, while the activities of the corresponding enzymes remained stable. The normal response of the transcription level of the apoptotic gene (diablo) to heat stress was also altered in metal-contaminated fish. The combination of metal and temperature stresses also modified the response of antioxidant metabolism induced by these stressors individually. This study contributes to a better understanding of the influences of natural stressors like temperature on biomarkers commonly used in

Intestinal parasite Acanthocephalus lucii (Acanthocephala) from European perch (Perca fluviatilis) as a bioindicator for lead pollution in the stream "Jevanský potok" near Prague, Czech Republic.

Science.gov (United States)

Jankovská, Ivana; Miholová, Daniela; Petrtýl, Miloslav; Romočuský, Stěpán; Kalous, Lukáš; Vadlejch, Jaroslav; Cadková, Zuzana; Langrová, Iva

2011-03-01

Lead concentrations in the tissues of perch and its parasites were determined as mg/kg dw. Lead was found at higher concentrations in the acanthocephalans (11.56) than in different tissues (liver, gonads and muscle with skin and bone) of perch. With respect to fish tissues, the highest concentrations of lead were present in the liver (1.24), followed by the gonads (0.57) whereas the lowest concentrations were in the muscle with skin and bone (0.21). The bioconcentration factors for lead indicated that parasites accumulate metals to a higher degree than fish tissues--lead concentrations in acanthocephalans were 9.32, 19.27 and 55.05 higher than in liver, gonads and muscles of host, respectively.

Effects of dietary n-3 and n-6 fatty acids levels on egg and larval quality of Eurasian perch

DEFF Research Database (Denmark)

Henrotte, E.; Overton, Julia Lynne; Kestemont, P.

2008-01-01

Three groups of 40 perch breeders were reared in order to study the effects of 3 different levels of dietary n-3 and n-6 fatty acids on egg quality. Two experimental diets, R1 and R2 (n-3/n-6 = 0.13 and 35.54, respectively), were compared to one commercial food, R3 (n-3/n-6 = 3.48.). Spawning and...

Effect of perches on liver health of hens.

Science.gov (United States)

Jiang, S; Hester, P Y; Hu, J Y; Yan, F F; Dennis, R L; Cheng, H W

2014-07-01

Fatty liver is a common energy metabolic disorder in caged laying hens. Considering that the egg industry is shifting from conventional cages to alternative housing systems such as enriched cages, the objective of this study was to determine the effects of perches on fat deposition and liver health in laying hens. Three hundred twenty-four 17-wk-old White Leghorn hens were housed in 1 of 4 treatments with 9 hens per cage. Treatment 1 hens never had access to perches during their life cycle. Treatment 2 hens had access to perches during the pullet phase only. Treatment 3 hens had access to perches during the laying phase only. Treatment 4 hens always had access to perches. Liver weight, abdominal fat pad weight, BW, liver fat, and circulating alanine transaminase, aspartate transaminase, and adiponectin were determined. Provision of perches during either the rearing or laying phase did not affect liver health in 71-wk-old hens. However, perch access compared with no perch access during the egg laying phase reduced relative fat pad weight. These results suggest that providing perches as a means of stimulating activity reduced abdominal fat deposition in caged hens during the laying period. However, perch access in caged hens was ineffective in reducing fat deposition in the liver and altering enzyme activities related to improved liver function. © 2014 Poultry Science Association Inc.

The state in the Eurasian doctrine

Directory of Open Access Journals (Sweden)

S N Lebedev

2016-12-01

Full Text Available The article considers the role of the state in the Eurasian doctrine, one of the most distinctive and significant movements of the Russian sociological and political-philosophical thought abroad in the 1920-1930’s. The issues addressed by the Eurasians are still relevant under the current epoch of the new Russian statehood construction and to a certain extent are implemented in the contemporary political practice. According to the classical Eurasian doctrine, all nations of “Russia-Eurasia” are united by the “place of development” and constitute a single historical and socio-cultural world, which organically combines elements of the East and the West. The Eurasian doctrine of the state proclaims the idea of strong government and powerful state, which represents the interests of the people and maintains direct connections with its citizens by combining the law and justice principles with the norms of morality, welfare and conscience. The article examines the key Eurasian concept “ideocratic state” and the essential characteristics of the Eurasian concept of the state system, such as ideocracy, autarchy, idea-ruler, and ruling selection. The key state-forming concept is “Pan-Eurasian nationalism” interpreted by the Eurasians as an archetype of ideology, a basis of the national idea. The authors consider basic principles of the socio-economic structure of the Eurasian state, including active participation of the state in the economic life of the country, the coexistence of public and private properties. According to the Eurasian doctrine, the state-planned economy and the state regulation of culture form the foundations of autarchic states that protect the country from economic and humanitarian intervention. The authors come to the conclusion that Eurasian theory of the state can significantly enrich nowadays scientific theory and help to solve the tasks of modernization of the Russian society at the present stage for it takes

Monitoring and sampling perched ground water in a basaltic terrain

International Nuclear Information System (INIS)

Hubbell, J.M.

1990-01-01

Perched ground water zones can provide significant information on water and contaminant movement. This paper presents information about perched ground water obtained from drilling and monitoring at a hazardous and radioactive waste disposal site at the Idaho National Engineering Laboratory. Six of forty-five wells drilled at the Radioactive Waste Management Complex have detected perched water in basalts above sedimentary interbeds. This paper describes the distribution and characteristics of perched ground water. It discusses perched water below the surficial sediments in wells at the RWMC, the characteristics of chemical constituents found in perched water, the implications for contaminant transport in the unsaturated zone of water, and the lateral extent of perched water. Recommendations are made to increase the probability of detecting and sampling low yield perched water zones. 6 refs., 6 figs., 2 tabs

Development of a bio-inspired UAV perching system

Science.gov (United States)

Xie, Pu

Although technologies of unmanned aerial vehicles (UAVs) including micro air vehicles (MAVs) have been greatly advanced in the recent years, it is still very difficult for a UAV to perform some very challenging tasks such as perching to any desired spot reliably and agilely like a bird. Unlike the UAVs, the biological control mechanism of birds has been optimized through millions of year evolution and hence, they can perform many extremely maneuverability tasks, such as perching or grasping accurately and robustly. Therefore, we have good reason to learn from the nature in order to significantly improve the capabilities of UAVs. The development of a UAV perching system is becoming feasible, especially after a lot of research contributions in ornithology which involve the analysis of the bird's functionalities. Meanwhile, as technology advances in many engineering fields, such as airframes, propulsion, sensors, batteries, micro-electromechanical-system (MEMS), and UAV technology is also advancing rapidly. All of these research efforts in ornithology and the fast growing development technologies in UAV applications are motivating further interests and development in the area of UAV perching and grasping research. During the last decade, the research contributions about UAV perching and grasping were mainly based on fixed-wing, flapping-wing, and rotorcraft UAVs. However, most of the current researches in UAV systems with perching and grasping capability are focusing on either active (powered) grasping and perching or passive (unpowered) perching. Although birds do have both active and passive perching capabilities depending on their needs, there is no UAV perching system with both capabilities. In this project, we focused on filling this gap. Inspired by the anatomy analysis of bird legs and feet, a novel perching system has been developed to implement the bionics action for both active grasping and passive perching. In addition, for developing a robust and

Polychlorinated biphenyls in adult black bass and yellow perch were not associated with their reproductive success in the upper Hudson River, New York, USA.

Science.gov (United States)

Maceina, Michael J; Sammons, Steven M

2013-07-01

Although production and use of polychlorinated biphenyls (PCBs) ceased nearly 35 yr ago, questions still remain concerning the potential chronic effects these compounds may have on wild fish, including their reproductive success. In the upper Hudson River, New York, USA, fish were exposed to PCBs primarily from 2 manufacturing plants located approximately 320 km upstream of New York City, New York, from the 1940s to 1977. The authors collected yellow perch (Perca flavescens), smallmouth bass (Micropterus dolomieu), and largemouth bass (M. salmoides) using electrofishing, measured PCBs in these adults, and estimated abundance and size of their offspring at age 1 yr (age-1 fish). Fish were collected annually from 2004 to 2009 from 1 control site upstream of the PCB discharge sites and from 2 sites downstream from where PCBs were released. These sites (pools) are separated by a series of dams, locks, and canals. Muscle tissue wet weight PCB and lipid-based PCB concentrations in adults in the 2 PCB exposure pools averaged approximately 1 to 3 µg/g and 100 to 500 µg/g, respectively. Age-1 abundances were not related to adult PCB concentrations but were inversely related to river flow. Size of age-1 fish was slightly greater at the PCB-exposure sites. Levels of PCBs in yellow perch, largemouth bass, and smallmouth bass in the upper Hudson River did not impair or reduce recruitment or reproductive success. Copyright © 2013 SETAC.

Spotlight on fish: light pollution affects circadian rhythms of European perch but does not cause stress.

Science.gov (United States)

Brüning, Anika; Hölker, Franz; Franke, Steffen; Preuer, Torsten; Kloas, Werner

2015-04-01

Flora and fauna evolved under natural day and night cycles. However, natural light is now enhanced by artificial light at night, particularly in urban areas. This alteration of natural light environments during the night is hypothesised to alter biological rhythms in fish, by effecting night-time production of the hormone melatonin. Artificial light at night is also expected to increase the stress level of fish, resulting in higher cortisol production. In laboratory experiments, European perch (Perca fluviatilis) were exposed to four different light intensities during the night, 0 lx (control), 1 lx (potential light level in urban waters), 10 lx (typical street lighting at night) and 100 lx. Melatonin and cortisol concentrations were measured from water samples every 3h during a 24 hour period. This study revealed that the nocturnal increase in melatonin production was inhibited even at the lowest light level of 1 lx. However, cortisol levels did not differ between control and treatment illumination levels. We conclude that artificial light at night at very low intensities may disturb biological rhythms in fish since nocturnal light levels around 1 lx are already found in urban waters. However, enhanced stress induction could not be demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

FDI DETERMINANTS IN THE EURASIAN ECONOMIC UNION COUNTRIES AND EURASIAN ECONOMIC INTEGRATION EFFECT ON FDI INFLOWS

Directory of Open Access Journals (Sweden)

Yerkezhan Zhumakankyzy Akhmetzaki

2017-09-01

Full Text Available The paper examines the potential determinants of foreign direct investment inflows into the region of Eurasian Economic Union, as well as incentives for investment into other neighboring countries. In the first model, the authors test a hypothesis on country specific foreign direct investment determinants for the Eurasian Economic Union region. The results of fixed effects estimation show that gross domestic product, infrastructure development and secondary education enrollment have a positive statistically significant effect on the foreign direct investment inflows into the region. Conversely, the impact of Customs Union on foreign direct investment appeared to be negative. Furthermore, in the second model of the natural experiment, the authors empirically test the hypothesis on Customs Union’s effect on foreign direct investment while controlling for both country and time effects. The model includes evaluating the impact of the policy change on foreign investment inflows. The natural experiment outcome also points to the negative effect of Eurasian economic integration on foreign direct investment inflows. Although the countries of Eurasian Economic Union have relatively business friendly regulations, such procedures as enforcing contracts, resolving insolvencies and dealing with construction permits are time-consuming. For attracting foreign investment, it is advisable to facilitate such procedures and make the process of setting up a new business less onerous. The research can be used as an outline for further examining of Eurasian economic integration and apart from that, the study results can be applied for practical purposes of policy elaboration aimed at stimulating foreign direct investment into the Eurasian Economic Union.

Habitat use and trophic position effects on contaminant bioaccumulation in fish indicated by stable isotope composition

Science.gov (United States)

The objective of our study was to determine the relationship between fish tissue stable isotope composition and total mercury or polychlorinated biphenyl (PCB) concentrations in a Great Lakes coastal food web. We sampled two resident fishes, Yellow Perch (Perca flavescens) and Bl...

Altered steroid metabolism in several teleost species exposed to endocrine disrupting substances in refuse dump leachate

NARCIS (Netherlands)

Noaksson, E.; Linderoth, M.; Bosveld, A.T.C.; Balk, L.

2003-01-01

Endocrine disruption associated with reproductive failure has been reported previously in female perch (Perca fluviatilis) and roach (Rutilus rutilus) from Lake Molnbyggen in Sweden and in female brook trout (Salvelinus fontinalis) from Vadbäcken, a stream emptying into Molnbyggen. Both Molnbyggen

Food habits of stunted and non-stunted white perch (Morone americana)

Science.gov (United States)

Gosch, N.J.C.; Stittie, J.R.; Pope, K.L.

2010-01-01

We studied food habits of white perch (Morone americana) from two populations with different stable states (stunted [Branched Oak Lake, Nebraska] and nonstunted [Pawnee Lake, Nebraska]) to determine if change in food habits of white perch is likely to occur in situations where a stunted white perch population is altered to a nonstunted state and vice versa. Three approaches were used to quantitatively describe seasonal (spring = March-May, summer = June-August, autumn = September-November) diets of white perch - 1) frequency of occurrence, 2) percentage of composition by volume, and 3) mean stomach fullness. White perch diets were dominated by cladocerans and dipterans in both reservoirs during all seasons. Fish egg predation was similar between reservoirs, and white perch rarely consumed fishes in either the stunted or the non-stunted population. Shifting a white perch population between stunted and non-stunted states will likely cause little or no change in food habits; fish in both states will primarily consume invertebrates.

Density and depth variations of Daphnia multilocus genotypes during a summer period in Lake Maarsseveen

NARCIS (Netherlands)

Ringelberg, J.; van Gool, E.; Brehm, Michaela

2004-01-01

The genotype composition of a Daphnia population complex during a summer period in Lake Maarsseveen (The Netherlands) was determined by allozyme analysis. The depth distribution, diel vertical migration and several parameters of the total population were measured. Young-of-the-year (0+) perch (Perca

2652-IJBCS-Article-Claudine Tiogue Tekou

African Journals Online (AJOL)

hp

article. 11 de la loi No 94 /01 du 20 janvier 1994. (Djeukam, 2012) et se résume à l' ..... The length-weight relationship and seasonal cycle in gonad weight and condition in perch. (Perca fluviatilis). Journal of Animal. Ecology, 20 (2): 201-219.

Dynamics and Control of Three-Dimensional Perching Maneuver under Dynamic Stall Influence

Science.gov (United States)

Feroskhan, Mir Alikhan Bin Mohammad

Perching is a type of aggressive maneuver performed by the class 'Aves' species to attain precision point landing with a generally short landing distance. Perching capability is desirable on unmanned aerial vehicles (UAVs) due to its efficient deceleration process that potentially expands the functionality and flight envelope of the aircraft. This dissertation extends the previous works on perching, which is mostly limited to two-dimensional (2D) cases, to its state-of-the-art threedimensional (3D) variety. This dissertation presents the aerodynamic modeling and optimization framework adopted to generate unprecedented variants of the 3D perching maneuver that include the sideslip perching trajectory, which ameliorates the existing 2D perching concept by eliminating the undesirable undershoot and reliance on gravity. The sideslip perching technique methodically utilizes the lateral and longitudinal drag mechanisms through consecutive phases of yawing and pitching-up motion. Since perching maneuver involves high rates of change in the angles of attack and large turn rates, introduction of three internal variables thus becomes necessary for addressing the influence of dynamic stall delay on the UAV's transient post-stall behavior. These variables are then integrated into a static nonlinear aerodynamic model, developed using empirical and analytical methods, and into an optimization framework that generates a trajectory of sideslip perching maneuver, acquiring over 70% velocity reduction. An impact study of the dynamic stall influence on the optimal perching trajectories suggests that consideration of dynamic stall delay is essential due to the significant discrepancies in the corresponding control inputs required. A comparative study between 2D and 3D perching is also conducted to examine the different drag mechanisms employed by 2D and 3D perching respectively. 3D perching is presented as a more efficient deceleration technique with respect to spatial costs and

Comparative perch selection in Southern Fiscal Lanius collaris and ...

African Journals Online (AJOL)

Here we tested for evidence of competition for perch space. ... is a product of different perch preferences, territoriality and the local plant community. Keywords: competition, interspecific territorial aggression, niche partitioning, sympatry ...

Transcriptional and biochemical markers in transplanted Perca flavescens to characterize cadmium- and copper-induced oxidative stress in the field

International Nuclear Information System (INIS)

Defo, Michel A.; Bernatchez, Louis; Campbell, Peter G.C.; Couture, Patrice

2015-01-01

Highlights: • Four-weeks exposure is sufficient to increase kidney metal levels in wild perch. • Cd and Cu affected indicators of retinoid metabolism and oxidative stress in fish. • Multi-level biological approaches are needed when assessing fish metal toxicology. • Changes at molecular level do not always mean changes at the functional level. • Wild juvenile perch may partly adjust to metal contamination by plastic responses. - Abstract: Despite recent progress achieved in elucidating the mechanisms underlying local adaptation to pollution, little is known about the evolutionary change that may be occurring at the molecular level. The goal of this study was to examine patterns of gene transcription and biochemical responses induced by metal accumulation in clean yellow perch (Perca flavescens) and metal depuration in contaminated fish in a mining and smelting region of Canada. Fish were collected from a reference lake (lake Opasatica) and a Cd, Cu and Zn contaminated lake (lake Dufault) located in the Rouyn-Noranda region (Qc, Canada) and caged for one or four weeks in their own lake or transplanted in the other lake. Free-ranging fish from the same lakes were also collected. Kidney Cd and Cu concentrations in clean fish caged in the contaminated lake increased with the time of exposure, but metal depuration did not occur in contaminated fish caged in the clean lake. After 4 weeks, the major retinoid metabolites analysed, the percentage of free dehydroretinol (dROH) and the retinol dehydrogenase-2 (rdh-2) transcription level in liver decreased in clean fish transplanted into the metal-contaminated lake, suggesting that metal exposure negatively impacted retinoid metabolism. However, we observed an increase in almost all of the retinoid parameters analysed in fish from the metal-impacted lake caged in the same lake, which we interpret as an adaptation response to higher ambient metal concentration. In support of this hypothesis, liver transcription levels

Transcriptional and biochemical markers in transplanted Perca flavescens to characterize cadmium- and copper-induced oxidative stress in the field

Energy Technology Data Exchange (ETDEWEB)

Defo, Michel A. [Institut National De La Recherche Scientifique (INRS), Centre Eau Terre Environnement, 490 De La Couronne, Québec, QC G1K 9A9 (Canada); Bernatchez, Louis [Institut De Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Québec, QC G1V 0A6 (Canada); Campbell, Peter G.C.; Couture, Patrice [Institut National De La Recherche Scientifique (INRS), Centre Eau Terre Environnement, 490 De La Couronne, Québec, QC G1K 9A9 (Canada)

2015-05-15

Highlights: • Four-weeks exposure is sufficient to increase kidney metal levels in wild perch. • Cd and Cu affected indicators of retinoid metabolism and oxidative stress in fish. • Multi-level biological approaches are needed when assessing fish metal toxicology. • Changes at molecular level do not always mean changes at the functional level. • Wild juvenile perch may partly adjust to metal contamination by plastic responses. - Abstract: Despite recent progress achieved in elucidating the mechanisms underlying local adaptation to pollution, little is known about the evolutionary change that may be occurring at the molecular level. The goal of this study was to examine patterns of gene transcription and biochemical responses induced by metal accumulation in clean yellow perch (Perca flavescens) and metal depuration in contaminated fish in a mining and smelting region of Canada. Fish were collected from a reference lake (lake Opasatica) and a Cd, Cu and Zn contaminated lake (lake Dufault) located in the Rouyn-Noranda region (Qc, Canada) and caged for one or four weeks in their own lake or transplanted in the other lake. Free-ranging fish from the same lakes were also collected. Kidney Cd and Cu concentrations in clean fish caged in the contaminated lake increased with the time of exposure, but metal depuration did not occur in contaminated fish caged in the clean lake. After 4 weeks, the major retinoid metabolites analysed, the percentage of free dehydroretinol (dROH) and the retinol dehydrogenase-2 (rdh-2) transcription level in liver decreased in clean fish transplanted into the metal-contaminated lake, suggesting that metal exposure negatively impacted retinoid metabolism. However, we observed an increase in almost all of the retinoid parameters analysed in fish from the metal-impacted lake caged in the same lake, which we interpret as an adaptation response to higher ambient metal concentration. In support of this hypothesis, liver transcription levels

Explaining growth variation over large spatial scales: Effects of temperature and food on walleye growth

DEFF Research Database (Denmark)

Mosgaard, Thomas; Venturelli, Paul; Lester, Nigel P.

2012-01-01

freshwater fish species in North America. We then use length at age data from yellow perch (Perca flavescens) to identify the mechanisms behind the remaining variation in the length at age – temperature relationship for walleye. A positive perch – walleye relationship indicates that the mechanism behind......Most fishes exhibit strong spatial variation in growth. Because fish growth and production are tightly linked, quantifying and explaining variation in growth can mean the difference between successful management and unforeseen collapse. However, disentangling the factors that are responsible...

Waterborne cadmium and nickel impact oxidative stress responses and retinoid metabolism in yellow perch

International Nuclear Information System (INIS)

Defo, Michel A.; Bernatchez, Louis; Campbell, Peter G.C.; Couture, Patrice

2014-01-01

Highlights: • Cd and Ni affected indicators of retinoid metabolism and oxidative stress in fish. • Liver rdh-2 transcription levels increase in fish exposed to waterborne Cd. • Liver REH and LdRAT activities increase with increasing kidney Cd concentration. • Changes at molecular levels do not always mean changes at the functional levels. • Multi-level biological approaches are needed when assessing fish metal toxicology. - Abstract: In this experiment, we studied the transcriptional and functional (enzymatic) responses of yellow perch (Perca flavescens) to metal stress, with a focus on oxidative stress and vitamin A metabolism. Juvenile yellow perch were exposed to two environmentally relevant concentrations of waterborne cadmium (Cd) and nickel (Ni) for a period of 6 weeks. Kidney Cd and Ni bioaccumulation significantly increased with increasing metal exposure. The major retinoid metabolites analyzed in liver and muscle decreased with metal exposure except at high Cd exposure where no variation was reported in liver. A decrease in free plasma dehydroretinol was also observed with metal exposure. In the liver of Cd-exposed fish, both epidermal retinol dehydrogenase 2 transcription level and corresponding enzyme activities retinyl ester hydrolase and lecithin dehydroretinyl acyl transferase increased. In contrast, muscle epidermal retinol dehydrogenase 2 transcription level decreased with Cd exposure. Among antioxidant defences, liver transcription levels of catalase, microsomal glutathione-S-transferase-3 and glucose-6-phosphate dehydrogenase were generally enhanced in Cd-exposed fish and this up-regulation was accompanied by an increase in the activities of corresponding enzymes, except for microsomal glutathione-S-transferase. No consistent pattern in antioxidant defence responses was observed between molecular and biochemical response when fish were exposed to Ni, suggesting a non-synchronous response of antioxidant defence in fish exposed to

Waterborne cadmium and nickel impact oxidative stress responses and retinoid metabolism in yellow perch

Energy Technology Data Exchange (ETDEWEB)

Defo, Michel A. [Institut national de la recherche scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, Québec G1K 9A9 (Canada); Bernatchez, Louis [Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec G1V 0A6 (Canada); Campbell, Peter G.C. [Institut national de la recherche scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, Québec G1K 9A9 (Canada); Couture, Patrice, E-mail: patrice.couture@ete.inrs.ca [Institut national de la recherche scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, Québec G1K 9A9 (Canada)

2014-09-15

Highlights: • Cd and Ni affected indicators of retinoid metabolism and oxidative stress in fish. • Liver rdh-2 transcription levels increase in fish exposed to waterborne Cd. • Liver REH and LdRAT activities increase with increasing kidney Cd concentration. • Changes at molecular levels do not always mean changes at the functional levels. • Multi-level biological approaches are needed when assessing fish metal toxicology. - Abstract: In this experiment, we studied the transcriptional and functional (enzymatic) responses of yellow perch (Perca flavescens) to metal stress, with a focus on oxidative stress and vitamin A metabolism. Juvenile yellow perch were exposed to two environmentally relevant concentrations of waterborne cadmium (Cd) and nickel (Ni) for a period of 6 weeks. Kidney Cd and Ni bioaccumulation significantly increased with increasing metal exposure. The major retinoid metabolites analyzed in liver and muscle decreased with metal exposure except at high Cd exposure where no variation was reported in liver. A decrease in free plasma dehydroretinol was also observed with metal exposure. In the liver of Cd-exposed fish, both epidermal retinol dehydrogenase 2 transcription level and corresponding enzyme activities retinyl ester hydrolase and lecithin dehydroretinyl acyl transferase increased. In contrast, muscle epidermal retinol dehydrogenase 2 transcription level decreased with Cd exposure. Among antioxidant defences, liver transcription levels of catalase, microsomal glutathione-S-transferase-3 and glucose-6-phosphate dehydrogenase were generally enhanced in Cd-exposed fish and this up-regulation was accompanied by an increase in the activities of corresponding enzymes, except for microsomal glutathione-S-transferase. No consistent pattern in antioxidant defence responses was observed between molecular and biochemical response when fish were exposed to Ni, suggesting a non-synchronous response of antioxidant defence in fish exposed to

Cannibalism in a size-structured population: energy extraction and control

NARCIS (Netherlands)

Persson, L.; Claessen, D.; de Roos, A.M.; Byström, P.; Sjögren, S.; Svanbäck, R.; Wahlström, E.; Westman, E.

2004-01-01

Recent size-structured cannibalistic models point to the importance of the energy gain by cannibals and also show that this gain may result in the emergence of giant individuals. We use a combination of a 10-year field study of a perch (Perca fluviatilis) population and quantitative within-season

Cannibalism in a size-structured population: Enery extraction and control

NARCIS (Netherlands)

Persson, L.; Claessen, D.; de Roos, A.M.; Bystrom, P.; Sjogren, S.; Svanback, R.; Wahlstrom, E.; Westman, E.

2004-01-01

Recent size-structured cannibalistic models point to the importance of the energy gain by cannibals and also show that this gain may result in the emergence of giant individuals. We use a combination of a 10-year field study of a perch (Perca fluviatilis) population and quantitative within-season

Bioaccumulation of decamethylcyclopentasiloxane in perch in Swedish lakes.

Science.gov (United States)

Kierkegaard, Amelie; Bignert, Anders; McLachlan, Michael S

2013-10-01

Decamethylcyclopentasiloxane (D5), a high production volume chemical used in personal care products, enters the environment both via air and sewage treatment plant (STP) recipients. It has been found in fish, and there is concern that it may be a bioaccumulative substance. In this work D5 was analyzed in perch from six Swedish lakes that did not receive STP effluent, and in perch and sediment from six lakes that received STP effluent. In the lakes receiving the STP effluent, the D5 concentrations in sediment varied over three orders of magnitude and were correlated with the number of persons connected to the STP normalized to the surface area of the receiving body. In the lakes not receiving effluent, the D5 levels in perch were all below the LOQ, while D5 was above the LOQ in almost all perch from lakes that received effluent. The D5 concentrations in perch and sediment from the lakes receiving STP effluent were correlated. This shows that STP effluent is a much more important source of D5 to aquatic ecosystems than atmospheric deposition, and that the risk of adverse effects of D5 on aquatic life will be greatest in small recipients receiving large amounts of STP effluent. The bioaccumulation of D5 was compared to that of PCB 180 on the basis of multimedia bioaccumulation factors (mmBAFs), which describe the fraction of the contaminant present in the whole aquatic environment (i.e. water and surface sediment) that is transferred to the fish. In four of the six lakes the mmBAF of D5 was >0.3 of the mmBAF of PCB 180. Given that PCB 180 is a known highly bioaccumulative chemical, this indicates that the bioaccumulation of D5 in perch is considerable. Copyright © 2012 Elsevier Ltd. All rights reserved.

Eurasian Economic Union Foundation : Issues of Global Regionalization

OpenAIRE

Lagutina, Maria

2014-01-01

This paper is devoted to the theoretical conceptualization of political-economic processes within the Eurasian Economic Union. The author elaborates on this project within the framework of “global regionalization” and regards it as a fledging “global region.” In this paper, the European Union is analyzed as a model of the existing global region. The Eurasian region also has its own specific traits and experience of post-Soviet integration. The article argues that for successful Eurasian integ...

MOLDOVA: MISSED ADVANTAGES OF EURASIAN INTEGRATION

Directory of Open Access Journals (Sweden)

Ludmila Vasiljevna Fokina

2015-01-01

Full Text Available The article is devoted to potentially missed advantages of Eurasian integration (EAEU for Moldova. Special attention is given to the branches in which the country could get evident advantages including agriculture, power engineering, external trade ties with the EAEU countries. Possible positive effects of Eurasian integration in solution of the Transnistrian problem, in the sphere of labour migration and other fields are also shown.

Impact of impingement on the Hudson River white perch population. Final report

Energy Technology Data Exchange (ETDEWEB)

Barnthouse, L.W.; Van Winkle, W.; Kirk, B.L.; Vaughan, D.S.

1982-02-01

This report summarizes a series of analyses of the magnitude and biological significance of the impingement of white perch at the Indian Point Nuclear Generating Station and other Hudson River power plants. Included in these analyses were evaluations of: (1) two independent lines of evidence relating to the magnitude of impingement impacts on the Hudson River white perch population; (2) the additional impact caused by entrainment of white perch; (3) data relating to density-dependent growth among young-of-the-year white perch; (4) the feasibility of performing population-level analyses of impingement impacts on the white perch populations of Chesapeake Bay and the Delaware River; and (5) the feasibility of using simple food chain and food web models to evaluate community-level effects of impingement and entrainment. Estimated reductions in the abundances of the 1974 and 1975 white perch year classes, caused by impingement and entrainment, were high enough that the possibility of adverse long-term effects cannot be excluded.

Safety of oxytetracycline (Terramycin TM-100F) administered in feed to hybrid striped bass, walleyes, and yellow perch

Science.gov (United States)

Gaikowski, M.P.; Wolf, J.C.; Schleis, S.M.; Gingerich, W.H.

2003-01-01

Oxytetracycline (Terramycin TM-100F, a medicated premix containing oxytetracycline at 220 g/kg) is approved in the United States to control certain systemic bacterial diseases of salmon and catfish when fed at a rate of 55-82.5 mg per kilogram of bodyweight per day for 10 d. Although oxytetracycline may also control certain systemic bacterial infections in coolwater or scaled warmwater fish, no safety data for such species are available. Our objective was to determine the safety of oxytetracycline administered in feed at nominal doses of 0, 82.5, 248, or 413 mg??kg-1??d-1 to yellow perch Perca flavescens and hybrid striped bass (striped bass Morone saxatilis x white bass M. chrysops) for 10 d and to walleye Sander vitreus (formerly Stizostedion vitreum) for 20 d. Yellow perch and hybrid striped bass consumed 50% to 100% of the diet, whereas walleye feed consumption was occasionally less than 50% of the diet. Feed or fecal material was present in the gastrointestinal tract of all necropsied walleyes except for one control fish. The single growth effect was that hybrid striped bass offered a nominal dose of 413 mg??kg-1??d-1 were significantly smaller than untreated controls. Oxytetracycline-related histopathological findings were limited to walleyes and were of low severity. The histopathological findings included decreased hematopoietic-lymphopoietic (H&L) tissue in the anterior kidneys, diffuse hyperplasia of the gill filament epithelium, and a decreased prevalence of fish with eosinophilic droplets in their renal tubular epithelial cells. Although the incidence of decreased H&L tissue tended to increase in proportion to oxytetracycline dose, this finding was statistically significant only for fish that received a nominal dose of 413 mg??kg-1??d-1. Given the pathogenicity of the types of bacteria that are controlled by oxytetracycline treatment and the long history of its use in major aquaculture species, the relative risk of the minor oxytetracycline

Effects of perch on feed consumption and behaviour of caged laying hens

OpenAIRE

E. VALKONEN; R. RINNE; J. VALAJA

2008-01-01

This experiment studied the effects of perches in furnished cages on behaviour and feed consumption of laying hens. The study used 352 Lohmann Selected Leghorn (LSL) hens. The hens were housed at 16 weeks of age in furnished cages in groups of 8 birds. The experiment lasted for 205 days. The treatments were: perches present from 16 weeks of age (P16), perches present from 19 weeks of age (P19), and no perches present (NP). Feed consumption and egg production were measured over the pre-laying ...

Structure and development of the saccular sensory epithelium in ...

African Journals Online (AJOL)

Structure and development of the saccular sensory epithelium in relation to otolith growth in the perch Perca fluviatilis (Telostei) ... Electron microscopy indicated: 1) The apical surface of each hair cell is covered with a ciliary bundle which varies in length in different epithelial regions. Each bundle is formed from a long ...

Perch availability and ground cover: factors that may constitute ...

African Journals Online (AJOL)

In Succulent Karoe, pale chanting goshawks occupied areas where perch density (16 natural and 122 artificial/25 hal was significantly higher than in unoccupied areas (8 natural and 12 artificial/25 hal. The high proportion of cover formed by natural perches (trees and shrubs; 36%) and the low proportion of open ground ...

Cormorant predation on PIT-tagged lake fish

DEFF Research Database (Denmark)

Skov, Christian; Jepsen, Niels; Baktoft, Henrik

2014-01-01

The present study use data from recovered PIT (Passive Integrated Transponder) tags to explore species-and size-specific annual predation rates by cormorants on three common lacustrine fishes (size range 120-367 mm) in a European lake; roach (Rutilus rutilus), common bream (Abramis brama) and perch...... (Perca fluviatilis). In addition, we quantify the level of age/size truncation that cormorant predation could introduce in a population of perch, an important fish for recreational angling as well as for trophic interactions and ecosystem function in European lakes. Based on three years of PIT tagging...... of fish in Lake Viborg and subsequent recoveries of PIT tags from nearby cormorant roosting and breeding sites, we show that cormorants are major predators of roach, bream and perch within the size groups we investigated and for all species larger individuals had higher predation rates. Perch appear...

Consumption of plant material by perch (Perca fluviatilis)

Czech Academy of Sciences Publication Activity Database

Zapletal, T.; Adámek, Zdeněk; Jurajda, Pavel; Roche, Kevin Francis; Všetičková, Lucie; Mareš, J.

2016-01-01

Roč. 65, č. 2 (2016), s. 95-97 ISSN 0139-7893 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:68081766 Keywords : dietary preference * diet breadth * biomanipulation * accidental feeding Subject RIV: EH - Ecology, Behaviour Impact factor: 0.739, year: 2016

The use of artificial spawning substrates in order to understand the factors influencing the spawning site selection, depth of egg strands deposition and hatching time of perch (Perca fluviatilis L.)

Czech Academy of Sciences Publication Activity Database

Čech, Martin; Vejřík, L.; Peterka, Jiří; Říha, Milan; Muška, Milan; Jůza, Tomáš; Draštík, Vladislav; Kratochvíl, Michal; Kubečka, Jan

2012-01-01

Roč. 71, č. 1 (2012), s. 170-179 ISSN 1129-5767 R&D Projects: GA ČR(CZ) GP206/09/P266 Institutional support: RVO:60077344 Keywords : SCUBA diving * aquatic vegetation * lake management * common stonewort Chara vulgaris * Eurasian water milfoil Myriophyllum spicatum Subject RIV: EG - Zoology Impact factor: 1.473, year: 2012

Cooled perch effects on performance and well-being traits in caged White Leghorn hens.

Science.gov (United States)

Hu, J Y; Hester, P Y; Makagon, M M; Vezzoli, G; Gates, R S; Xiong, Y J; Cheng, H W

2016-12-01

We assessed the effects of chilled water cooling perches on hen performance and physiological and behavioral parameters under "natural" high temperatures during the 2013 summer with a 4-hour acute heating episode. White Leghorns at 16 wk of age (N = 162) were randomly assigned to 18 cages (n = 9) arranged into 3 units. Each unit was assigned to one of the 3 treatments through 32 wk of age: 1) cooled perches, 2) air perches, and 3) no perches. Chilled water (10°C) was circulated through the cooled perches when cage ambient temperature exceeded 25°C. At the age of 27.6 wk, hens were subjected to a 4-hour acute heating episode of 33.3°C and plasma corticosterone was determined within 2 hours. Egg production was recorded daily. Feed intake and egg and shell quality were measured at 5-week intervals. Feather condition, foot health, adrenal and liver weights, plasma corticosterone, and heat shock protein 70 mRNA were determined at the end of the study at 32 wk of age. The proportion of hens per cage perching, feeding, drinking, panting, and wing spreading was evaluated over one d every 5 wks and on the d of acute heat stress. There were no treatment effects on the measured physiological and production traits except for nail length. Nails were shorter for cooled perch hens than control (P = 0.002) but not air perch hens. Panting and wing spread were observed only on the day of acute heat stress. The onset of both behaviors was delayed for cooled perch hens, and they perched more than air perch hens following acute heat stress (P = 0.001) and at the age 21.4 wk (P = 0.023). Cooled perch hens drank less than control (P = 0.019) but not air perch hens at the age 21.4 wk. These results indicate that thermally cooled perches reduced thermoregulatory behaviors during acute heat stress, but did not affect their performance and physiological parameters under the ambient temperature imposed during this study. Published by Oxford University Press on behalf of

Combined effects of temperature and metal exposure on the fatty acid composition of cell membranes, antioxidant enzyme activities and lipid peroxidation in yellow perch (Perca flavescens)

International Nuclear Information System (INIS)

Fadhlaoui, Mariem; Couture, Patrice

2016-01-01

Highlights: • The fatty acid composition of yellow perch muscle at 9 °C was enhanced in monounsaturated and polyunsaturated fatty acids compared to fish maintained at 28 °C. • The thermal adjustment of muscle phospholipid fatty acid profiles is likely due to modifications of desaturase and elongase activities. • Exposure to Ni and Cd modified muscle phospholipid fatty acid composition in a temperature-dependent manner. • The higher fatty polyinsaturation in cold-acclimated fish did not increase their vulnerability to peroxidation. • Lower concentrations of malondialdehyde were measured in warm-acclimated, Ni-exposed fish, suggesting an overcompensation of antioxidant mechanisms that could explain their lower condition. - Abstract: The aim of this study was to investigate the combined effects of temperature and metal contamination (cadmium and nickel) on phospholipid fatty acid composition, antioxidant enzyme activities and lipid peroxidation in fish. Yellow perch were acclimated to two different temperatures (9 °C and 28 °C) and exposed either to Cd or Ni (respectively 4 μg/L and 600 μg/L) for seven weeks. Superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase activities and glutathione concentration were measured as indicators of antioxidant capacities, while malondialdehyde concentration was used as an indicator of lipid peroxidation. Poikilotherms including fish counteract the effects of temperature on phospholipid fatty acid ordering by remodelling their composition to maintain optimal fluidity. Accordingly, in our study, the fatty acid composition of yellow perch muscle at 9 °C was enhanced in monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) compared to fish maintained at 28 °C, in agreement with the theory of homeoviscous adaptation. Using ratios of various fatty acids as surrogates for desaturase and elongase activities, our data suggests that modification of the activity of these enzymes is

Combined effects of temperature and metal exposure on the fatty acid composition of cell membranes, antioxidant enzyme activities and lipid peroxidation in yellow perch (Perca flavescens)

Energy Technology Data Exchange (ETDEWEB)

Fadhlaoui, Mariem; Couture, Patrice, E-mail: patrice.couture@ete.inrs.ca

2016-11-15

Highlights: • The fatty acid composition of yellow perch muscle at 9 °C was enhanced in monounsaturated and polyunsaturated fatty acids compared to fish maintained at 28 °C. • The thermal adjustment of muscle phospholipid fatty acid profiles is likely due to modifications of desaturase and elongase activities. • Exposure to Ni and Cd modified muscle phospholipid fatty acid composition in a temperature-dependent manner. • The higher fatty polyinsaturation in cold-acclimated fish did not increase their vulnerability to peroxidation. • Lower concentrations of malondialdehyde were measured in warm-acclimated, Ni-exposed fish, suggesting an overcompensation of antioxidant mechanisms that could explain their lower condition. - Abstract: The aim of this study was to investigate the combined effects of temperature and metal contamination (cadmium and nickel) on phospholipid fatty acid composition, antioxidant enzyme activities and lipid peroxidation in fish. Yellow perch were acclimated to two different temperatures (9 °C and 28 °C) and exposed either to Cd or Ni (respectively 4 μg/L and 600 μg/L) for seven weeks. Superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase activities and glutathione concentration were measured as indicators of antioxidant capacities, while malondialdehyde concentration was used as an indicator of lipid peroxidation. Poikilotherms including fish counteract the effects of temperature on phospholipid fatty acid ordering by remodelling their composition to maintain optimal fluidity. Accordingly, in our study, the fatty acid composition of yellow perch muscle at 9 °C was enhanced in monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) compared to fish maintained at 28 °C, in agreement with the theory of homeoviscous adaptation. Using ratios of various fatty acids as surrogates for desaturase and elongase activities, our data suggests that modification of the activity of these enzymes is

The acute toxicity of the metaldehyde on the climbing perch

Science.gov (United States)

Wahida Mohamad Ismail, Syamimi; Aini Dahalan, Farrah; Zakaria, Ammar; Mad Shakaff, Ali Yeon; Aqlima Ahmad, Siti; Shukor, Mohd Yunus Abd; Khalizan Sabullah, Mohd; Khalil, Khalilah Abdul; Jalil, Mohd Faizal Ab

2018-03-01

In Asia, Climbing perch (Anabas testudineus) is commonly found in paddy fields and irrigation systems. Due to its habitat, Climbing perch is exposed to toxic pesticides used in paddy fields such as metaldehyde which is one of the most widely used molluscicide. This study aims to determine the acute toxicity Lethal Concentration50 (LC50) of metaldehyde and its effect on the behaviour and physical changes of the Climbing perch. The fish mortality responses to six different metaldehyde concentrations ranging from 180 to 330 mg/L were investigated. The 96-h LC50 values were determined and analysed using three different analysis methods which is arithmetic, logarithmic and probit graphic. The LC50 values obtained in this study were 239, 234 and 232 mg/L, respectively. After 96-h of exposure to metaldehyde, the fish showed a series of abnormal behavioural response in all cases: imbalance position, and restlessness of movement. The LC50 values show that metaldehyde is moderately toxic to the Climbing perch indicating that metaldehyde is not destructive to Climbing perch. However, long term exposure of aquatic organisms to the metaldehyde means a continuous health risk for the fish population as they are more vulnerable and it is on high risk for human to consume this toxicated fishes.

ROMANIA AND THE EURASIAN UNION. PLANS, PREDICTIONS AND PERSPECTIVES

OpenAIRE

Mircea-Cristian GHENGHEA

2016-01-01

Following the events in Ukraine, Romania might represent one of the key points for the Eurasian perspectives that have circulated in the last years in Moscow. Through our text we intend to present and to highlight the main ideas and plans of Eurasian inspiration regarding Romania, as well as the interesting predictions made, in certain moments, by some representative characters for the Eurasian paradigm, like Aleksandr Dugin, for instance, who is its main ideologist and promoter. At the same ...

Demonstrations of bio-inspired perching landing gear for UAVs

Science.gov (United States)

Tieu, Mindy; Michael, Duncan M.; Pflueger, Jeffery B.; Sethi, Manik S.; Shimazu, Kelli N.; Anthony, Tatiana M.; Lee, Christopher L.

2016-04-01

Results are presented which demonstrate the feasibility and performance of two concepts of biologically-inspired landing-gear systems that enable bird-sized, unmanned aerial vehicles (UAV's) to land, perch, and take-off from branchlike structures and/or ledges. The first concept follows the anatomy of birds that can grasp ahold of a branch and perch as tendons in their legs are tensioned. This design involves a gravity-activated, cable-driven, underactuated, graspingfoot mechanism. As the UAV lands, its weight collapses a four-bar linkage pulling a cable which curls two opposing, multi-segmented feet to grasp the landing target. Each foot is a single, compliant mechanism fabricated by simultaneouly 3D-printing a flexible thermo-plastic and a stiffer ABS plastic. The design is optimized to grasp structures over a range of shapes and sizes. Quasi-static and flight tests of this landing gear affixed to RC rotorcraft (24 cm to 550 cm in diameter) demonstrate that the aircraft can land, perch, and take-off from a tree branch, rectangular wood board, PVC pipe, metal hand rail, chair armrest, and in addition, a stone wall ledge. Stability tests show that perching is maintained under base and wind disturbances. The second design concept, inspired by roosting bats, is a two-material, 3D-printed hooking mechanism that enables the UAV to stably suspend itself from a wire or small-diameter branch. The design balances structural stiffness for support and flexibility for the perching process. A flight-test demonstrates the attaching and dis-engaging of a small, RC quadcopter from a suspended line.

Hatching success in brackish water of Perca fluviatilis eggs obtained from the western Baltic Sea

DEFF Research Database (Denmark)

Christensen, Emil Aputsiaq Flindt; Skovrind, Mikkel; Olsen, Morten Tange

2016-01-01

tolerance of the eggs in vivo, and the salinities at which some populations spawn in situ (7 vs. 9.6 ‰). In the present study, hatching success of perch was determined in vivo for a Danish, western Baltic, brackish water population at salinities of 4, 7, 10 and 12 ‰. Furthermore, in order to place...... the population genetically among other European perch populations, individual egg samples were sequenced for a 390 base pair fragment of the mtDNA Dloop region. Hatching occurred at all four salinities, with no statistical differences among treatments. Successful hatching at 12 ‰ is well above salinities of 7......‰, which has previously been the highest reported from in vivo studies. This discrepancy is likely to be a result of methodological differences (e.g. different temperature) or perhaps interspecific variability in egg hatching abilities among perch populations. The perch from the present study consisted...

Nutritional composition and shelflife of the lake victoria nile perch ...

African Journals Online (AJOL)

Nile perch, the most important commercial fish species from the Lake Victoria fishery, contributes about 67% of Kenya's total annual fish export earnings. Despite the Nile perch being an important foreign exchange earner, little information is available on its nutritional composition and shelf life on ice, information that is ...

Perched aquifers - their potential impact on contaminant transport in the southern High Plains, Texas

International Nuclear Information System (INIS)

Mullican, W.F. III; Fryar, A.E.; Johns, N.D.

1993-01-01

Understanding the hydrogeology and hydrochemistry of perched aquifers at potential and known contaminated waste sites has become increasingly important because of the impact these aquifers may have on contaminant transport independent of regional aquifer processes. Investigations of a perched aquifer above the Ogallala aquifer are being conducted in the region of the U.S. Department of Energy's Pantex Plant, a proposed Superfund site, located approximately 20 mi northeast of Amarillo, Texas. Since the early 1950s, a small playa basin located on the Pantex Plant has been used as a waste-water discharge pond with daily discharge rates ranging from 400,000 to 1 million gal. The focus of this investigation is an unconfined, perched aquifer that overlies a thick silty clay sequence within the upper, mostly unsaturated part of the Ogallala Formation (Neogene). In the area of the Pantex Plant, measured depths to the perched aquifer range from 200 to 300 ft below land surface, whereas depth to the regional Ogallala aquifer ranges from 375 to 500 ft. The potentiometric surface of the perched aquifer typically represents groundwater mounds proximal to the playas and thins into trough in the interplaya areas. Hydrologic gradients of the primary mound under investigation are relatively high, ranging from 28 to 45 ft/mi. Calculated transmissivities have a geometric mean of 54 ft 2 /day, with saturated thicknesses ranging from 4 to 1000 ft. Modeling of the perched aquifer was designed to determine how much, if any, discharge to the small playa basin has enhanced recharge to the perched aquifers and increased the vertical and lateral extent of the perched aquifer. Preliminary results indicate that measurements of vertical conductance through the perching silty-clay sequence and recharge rates through playas are critical for calibrating the model. Accurate delineation of rates and flow directions in the perched aquifer is critical to any successful remediation effort

137 ancient human genomes from across the Eurasian steppes.

Science.gov (United States)

Damgaard, Peter de Barros; Marchi, Nina; Rasmussen, Simon; Peyrot, Michaël; Renaud, Gabriel; Korneliussen, Thorfinn; Moreno-Mayar, J Víctor; Pedersen, Mikkel Winther; Goldberg, Amy; Usmanova, Emma; Baimukhanov, Nurbol; Loman, Valeriy; Hedeager, Lotte; Pedersen, Anders Gorm; Nielsen, Kasper; Afanasiev, Gennady; Akmatov, Kunbolot; Aldashev, Almaz; Alpaslan, Ashyk; Baimbetov, Gabit; Bazaliiskii, Vladimir I; Beisenov, Arman; Boldbaatar, Bazartseren; Boldgiv, Bazartseren; Dorzhu, Choduraa; Ellingvag, Sturla; Erdenebaatar, Diimaajav; Dajani, Rana; Dmitriev, Evgeniy; Evdokimov, Valeriy; Frei, Karin M; Gromov, Andrey; Goryachev, Alexander; Hakonarson, Hakon; Hegay, Tatyana; Khachatryan, Zaruhi; Khaskhanov, Ruslan; Kitov, Egor; Kolbina, Alina; Kubatbek, Tabaldiev; Kukushkin, Alexey; Kukushkin, Igor; Lau, Nina; Margaryan, Ashot; Merkyte, Inga; Mertz, Ilya V; Mertz, Viktor K; Mijiddorj, Enkhbayar; Moiyesev, Vyacheslav; Mukhtarova, Gulmira; Nurmukhanbetov, Bekmukhanbet; Orozbekova, Z; Panyushkina, Irina; Pieta, Karol; Smrčka, Václav; Shevnina, Irina; Logvin, Andrey; Sjögren, Karl-Göran; Štolcová, Tereza; Tashbaeva, Kadicha; Tkachev, Alexander; Tulegenov, Turaly; Voyakin, Dmitriy; Yepiskoposyan, Levon; Undrakhbold, Sainbileg; Varfolomeev, Victor; Weber, Andrzej; Kradin, Nikolay; Allentoft, Morten E; Orlando, Ludovic; Nielsen, Rasmus; Sikora, Martin; Heyer, Evelyne; Kristiansen, Kristian; Willerslev, Eske

2018-05-09

For thousands of years the Eurasian steppes have been a centre of human migrations and cultural change. Here we sequence the genomes of 137 ancient humans (about 1× average coverage), covering a period of 4,000 years, to understand the population history of the Eurasian steppes after the Bronze Age migrations. We find that the genetics of the Scythian groups that dominated the Eurasian steppes throughout the Iron Age were highly structured, with diverse origins comprising Late Bronze Age herders, European farmers and southern Siberian hunter-gatherers. Later, Scythians admixed with the eastern steppe nomads who formed the Xiongnu confederations, and moved westward in about the second or third century BC, forming the Hun traditions in the fourth-fifth century AD, and carrying with them plague that was basal to the Justinian plague. These nomads were further admixed with East Asian groups during several short-term khanates in the Medieval period. These historical events transformed the Eurasian steppes from being inhabited by Indo-European speakers of largely West Eurasian ancestry to the mostly Turkic-speaking groups of the present day, who are primarily of East Asian ancestry.

Woody structure facilitates invasion of woody plants by providing perches for birds.

Science.gov (United States)

Prather, Chelse M; Huynh, Andrew; Pennings, Steven C

2017-10-01

Woody encroachment threatens prairie ecosystems globally, and thus understanding the mechanisms that facilitate woody encroachment is of critical importance. Coastal tallgrass prairies along the Gulf Coast of the US are currently threatened by the spread of several species of woody plants. We studied a coastal tallgrass prairie in Texas, USA, to determine if existing woody structure increased the supply of seeds from woody plants via dispersal by birds. Specifically, we determined if (i) more seedlings of an invasive tree ( Tridacia sebifera ) are present surrounding a native woody plant ( Myrica cerifera ); (ii) wooden perches increase the quantity of seeds dispersed to a grassland; and (iii) perches alter the composition of the seed rain seasonally in prairie habitats with differing amounts of native and invasive woody vegetation, both underneath and away from artificial wooden perches. More T. sebifera seedlings were found within M. cerifera patches than in graminoid-dominated areas. Although perches did not affect the total number of seeds, perches changed the composition of seed rain to be less dominated by grasses and forbs. Specifically, 20-30 times as many seeds of two invasive species of woody plants were found underneath perches independent of background vegetation, especially during months when seed rain was highest. These results suggest that existing woody structure in a grassland can promote further woody encroachment by enhancing seed dispersal by birds. This finding argues for management to reduce woody plant abundance before exotic plants set seeds and argues against the use of artificial perches as a restoration technique in grasslands threatened by woody species.

ROMANIA AND THE EURASIAN UNION. PLANS, PREDICTIONS AND PERSPECTIVES

Directory of Open Access Journals (Sweden)

Mircea-Cristian GHENGHEA

2016-03-01

Full Text Available Following the events in Ukraine, Romania might represent one of the key points for the Eurasian perspectives that have circulated in the last years in Moscow. Through our text we intend to present and to highlight the main ideas and plans of Eurasian inspiration regarding Romania, as well as the interesting predictions made, in certain moments, by some representative characters for the Eurasian paradigm, like Aleksandr Dugin, for instance, who is its main ideologist and promoter. At the same time, one must not neglect the signals of discontent from Moscow about the need of dissipating the so-called sanitary cordon of the Western powers, in which the Baltic States, Poland, and Romania are included – another aspect bearing a particular importance for understanding certain gestures, attitudes and statements related to the role and the place of the Eurasian Union.

Perch population assessment in lakes reclaimed using oil-sands derived material

International Nuclear Information System (INIS)

Heuvel, M.R. van den; Dixon, D.G.; Power, M.; Boerger, H.; MacKinnon, M.D.; Meer, T. van

1995-01-01

The mining and extraction of petroleum products from oil-sands involves large areas of land and produces enormous volumes of tailings. One possible land reclamation option is to incorporate fine-tailings material into the bottoms of constructed lakes capped with natural surface water. The wet landscape method represents potential risk to aquatic biota-naphthenic acids and PAHs elute from pore water contained in the fine-tailings substrate. In spring 1995 yellow perch were stocked into a large-scale (5ha) experimental pond that consisted of fine-tailings capped with natural water as well as into two other reclaimed ponds that were constructed with oil-sands overburden material. Prior to stocking of perch, ponds had colonized with cyprinids, macrophytes and benthic invertebrates over a two year period. Perch were sampled in fall 1995 for age, condition factor, liver size, gonad size, fecundity, stomach contents, liver mixed-function oxygenase activity (MFO), bile PAH metabolites and plasma steroid hormones. When compared to the source lake, perch in the DP did not show reduced reproductive potential. Perch in all of the reclaimed ponds demonstrated exposure to organic compounds as indicated by marginally induced MFO activity and increased liver size. Exposure to naphthenates and PAHs in water as well as ecological environmental factors will be discussed

Monitoring and sampling perched ground water in a basaltic terrain

International Nuclear Information System (INIS)

Hubbell, J.M.

1990-01-01

Perched ground water zones are often overlooked in monitoring plans, but they can provide significant information on water and contaminant movement. This paper presents information about perched ground water obtained from drilling and monitoring at a hazardous and radioactive waste disposal site at the Idaho National Engineering Laboratory. Six of forty-five wells drilled at the Radioactive Waste Management Complex have detected perched water in basalts above sedimentary interbeds. Perched water has been detected at depths of 90 and 210 ft below land surface, approximately 370 ft above the regional water table. Eighteen years of water level measurements from one well at a depth of 210 ft indicate a consistent source of water. Water level data indicate a seasonal fluctuation. The maximum water level in this well varies within a 0.5 ft interval, suggesting the water level reaches equilibrium with the inflow to the well at this height. Volatile organic constituents have been detected in concentrations from 1.2 to 1.4 mg/L of carbon tetrachloride. Eight other volatile organics have been detected. The concentrations of organics are consistent with the prevailing theory of movement by diffusion in the gaseous phase. Results of tritium analyses indicate water has moved to a depth of 86 ft in 17 yr. Results of well sampling analyses indicate monitoring and sampling of perched water can be a valuable resource for understanding the hydrogeologic environment of the vadose zone at disposal sites

Letter Report: Stable Hydrogen and Oxygen Isotope Analysis of B-Complex Perched Water Samples

Energy Technology Data Exchange (ETDEWEB)

Lee, Brady D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Moran, James J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nims, Megan K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Saunders, Danielle L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-04-13

Fine-grained sediments associated with the Cold Creek Unit at Hanford have caused the formation of a perched water aquifer in the deep vadose zone at the B Complex area, which includes waste sites in the 200-DV-1 Operable Unit and the single-shell tank farms in Waste Management Area B-BX-BY. High levels of contaminants, such as uranium, technetium-99, and nitrate, make this aquifer a continuing source of contamination for the groundwater located a few meters below the perched zone. Analysis of deuterium (²H) and 18-oxygen (¹⁸O) of nine perched water samples from three different wells was performed. Samples represent time points from hydraulic tests performed on the perched aquifer using the three wells. The isotope analyses showed that the perched water had δ²H and δ¹⁸O ratios consistent with the regional meteoric water line, indicating that local precipitation events at the Hanford site likely account for recharge of the perched water aquifer. Data from the isotope analysis can be used along with pumping and recovery data to help understand the perched water dynamics related to aquifer size and hydraulic control of the aquifer in the future.

Eurasian Union on the Viewpoint of China: Geopolitical Perspective

Directory of Open Access Journals (Sweden)

Guo Cheng

2015-12-01

Full Text Available This article is about geopolitical strategic analyze of Russian President Vladimir Putin’s “Eurasian Union” strategy from Chinese viewpoint. The article describes historical background of Eurasian Union, its geopolitical purposes, achievements and weakness, particularly from China's national strategic design and stance of Central Asia in Eurasian Continent. The geopolitical analysis of possibility for Sino-Russian Alliance and realistic difficulties of it are provided. Different point of Chinese experts on Russia-West relations are given. Some of them believe that he Warsaw Pact and the Cold War revival in the CIS, its purpose is to play as geopolitical blunders against the Western countries under the leadership of NATO, IMF and the United States. While others, take into consideration the US-Russian Strategic Arms Reduction Treaty, and Russia’s actively participation in the former Group of Eight, accession to WTO and other initiatives that indicates the current Moscow is not the Soviet Union, and does not exclude cooperation with existing international system dominated by the Western world. And finally, China's own Eurasian strategy design is represented, especially China’s foreign policy options on Central Asia as solutions to some current existing geopolitical differences between China and Russia’s own Eurasian Strategy in order to achieve mutual win-set goal.

Intraspecific variation in gill morphology of juvenile Nile perch, Lates niloticus, in Lake Nabugabo, Uganda

Science.gov (United States)

Paterson, Jaclyn A.; Chapman, Lauren J.; Schofield, Pamela J.

2010-01-01

Several studies have demonstrated intraspecific variation in fish gill size that relates to variation in dissolved oxygen (DO) availability across habitats. In Lake Nabugabo, East Africa, ecological change over the past 12 years has coincided with a shift in the distribution of introduced Nile perch such that a larger proportion of the population now inhabits waters in or near wetland ecotones where DO is lower than in open waters of the lake. In this study, we compared gill size of juvenile Nile perch between wetland and exposed (open-water) habitats of Lake Nabugabo in 2007, as well as between Nile perch collected in 1996 and 2007. For Nile perch of Lake Nabugabo [<20 cm total length (TL)], there was a significant habitat effect on some gill traits. In general, fish from wetland habitats were characterized by a longer total gill filament length and average gill filament length than conspecifics from exposed habitats. Nile perch collected from wetland areas in 2007 had significantly larger gills (total gill filament length) than Nile perch collected in 1996, but there was no difference detected between Nile perch collected from exposed sites in 2007 and conspecifics collected in 1996.

Susceptibility of pike-perch Sander lucioperca to a panel of ranavirus isolates

DEFF Research Database (Denmark)

Jensen, Britt Bang; Holopainen, Riikka; Tapiovaara, Hannele

2011-01-01

The host range of ranaviruses was investigated by challenging pike-perch (Sander lucioperca) with the following ranavirus isolates: epizootic haematopoietic necrosis virus (EHNV), European sheatfish virus (ESV), European catfish virus (ECV), pike-perch iridovirus (PPIV), short-finned eel virus...

Distribution of Nile perch Lates niloticus in southern Lake Victoria is ...

African Journals Online (AJOL)

Although Nile perch Lates niloticus is assumed to be sensitive to low oxygen concentrations, it was found in deep water in Lake Victoria, where oxygen depletion is common during the rainy season. Since factors determining Nile perch distribution are not well understood its spatial distribution in the Mwanza Gulf of Lake ...

Influence of artificially induced light pollution on the hormone system of two common fish species, perch and roach, in a rural habitat.

Science.gov (United States)

Brüning, Anika; Kloas, Werner; Preuer, Torsten; Hölker, Franz

2018-01-01

Almost all life on earth has adapted to natural cycles of light and dark by evolving circadian and circannual rhythms to synchronize behavioural and physiological processes with the environment. Artificial light at night (ALAN) is suspected to interfere with these rhythms. In this study we examined the influence of ALAN on nocturnal melatonin and sex steroid blood concentrations and mRNA expression of gonadotropins in the pituitary of European perch ( Perca fluviatilis ) and roach ( Rutilus rutilus ). In a rural experimental setting, fish were held in net cages in drainage channels experiencing either additional ALAN of ~15 lx at the water surface or natural light conditions at half-moon. No differences in melatonin concentrations between ALAN and natural conditions were detected. However, blood concentration of sex steroids (17β-estradiol; 11-ketotestosterone) as well as mRNA expression of gonadotropins (luteinizing hormone, follicle stimulating hormone) was reduced in both fish species. We conclude that ALAN can disturb biological rhythms in fish in urban waters. However, impacts on melatonin rhythm might have been blurred by individual differences, sampling methods and moonlight. The effect of ALAN on biomarkers of reproduction suggests a photo-labile period around the onset of gonadogenesis, including the experimental period (August). Light pollution therefore has a great potential to influence crucial life history traits with unpredictable outcome for fish population dynamics.

The biology of perch and related fish

National Research Council Canada - National Science Library

Craig, John F; Craig, John

1987-01-01

This book presents a definitive volume on perch and related fish. In the introduction an outline is given on the characteristics of the order Perciformes, the suborder Percoidea and the family Percidae...

Ancient DNA reveals past existence of Eurasian lynx in Spain

DEFF Research Database (Denmark)

Rodríguez-Varela, R.; García, N.; Nores, C.

2016-01-01

. The paleontological record and our data indicate a population replacement of the Iberian lynx by the Eurasian lynx during the Pleistocene/Holocene transition in the Cantabrian cornice of Spain. Phylogeographic patterns of Late Pleistocene and Holocene Eurasian lynx from Iberia, France, Italy and Denmark show...

Investigation of Two Insect Species for Control of Eurasian Watermilfoil.

Science.gov (United States)

1981-02-01

21 6 Litodactylus leucogaster adult infected with the fungus Beauveria bassiana ............................................ 21 Litodactylus...entomopathogenic fungus, Beauveria bassiana (Balsamo) Vuillemin (figure 6) was always present but never epidemic. It also increased in ) adundance in...infected with the fungus Beauveria bassiana .4 Figure 7. Litodactylus leucogaster adult feeding on female flower of Eurasian watermilfoil Figure 8. Eurasian

First records of a European cladoceran, Bythotrephes cederstroemi, in Lakes Erie and Huron

Science.gov (United States)

Bur, Michael T.; Klarer, David M.; Krieger, Kenneth A.

1986-01-01

Adult forms of the cladoceran Bythotrephes cederstroemi Schoedler (Cercopagidae), a widespread European freshwater zooplankter, occurred in the stomachs of four common species of Lake Erie fish (yellow perch, Perca flavescens; white perch, Morone americana; white bass, M. chrysops; and walleye, Stizostedion vitreum vitreum) collected in early October 1985. The fish were collected at several stations in the nearshore open waters of the central basin between Ashtabula and Huron, Ohio. Other investigators have seen this species in other locations in Lake Erie and also in Lake Huron. The report of B. cederstroemi in Lake Huron in December 1984 appears to be the first record of this species in North America.

Macrophytes shape trophic niche variation among generalist fishes

Czech Academy of Sciences Publication Activity Database

Vejříková, Ivana; Eloranta, A. P.; Vejřík, Lukáš; Šmejkal, Marek; Čech, Martin; Sajdlová, Zuzana; Frouzová, Jaroslava; Kiljunen, M.; Peterka, Jiří

2017-01-01

Roč. 12, č. 5 (2017), č. článku e0177114. E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) EE2.3.20.0204; GA MŠk(CZ) 7F14316; GA MŠk LM2015075 Institutional support: RVO:60077344 Keywords : roach Rutilus rutilus * perch Perca fluviatilis * Scardinius erythrophthalmus * stable-isotopes Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 2.806, year: 2016

Use of perches and seed dispersal by birds in an abandoned pasture in the Porto Ferreira state park, southeastern Brazil

Directory of Open Access Journals (Sweden)

S. Athiê

Full Text Available Abstract We investigated the efficiency of different kinds of perches in attracting seed disperser-birds and increasing the seed rain in a degraded area located in the northeast region of São Paulo State. We installed seed traps under natural perches (NPs, living trees; simple artificial perches (SAPs of 3m tall and a crossbar; elaborate artificial perches (EAPs of 7m tall and three crossbars, and in a control area. Results showed the number of bird-dispersed seeds deposited was proportional to the number of structures for perching. The NPs also have provided other resources for birds such as food and shelter. Comparing visitation between artificial perches, there was greater use of EAPs also for having more perching structures and for being taller, providing better airspace visibility for predatory birds and tyrant-flycatchers, important seed dispersers. Thus, natural and artificial perches with similar characteristics to the EAPs are the most recommended as a base or complementary method for the restoration of degraded areas near to propagules source, also contributing to the maintenance of local fauna.

Nutritional profiling of Eurasian woodcock meat: chemical composition and myoglobin characterization.

Science.gov (United States)

Landi, Nicola; Ragucci, Sara; Di Giuseppe, Antonella Ma; Russo, Rosita; Poerio, Elia; Severino, Valeria; Di Maro, Antimo

2018-04-10

Meat from birds is a rich source of proteins for the human diet. In this framework, Eurasian woodcock (Scolopax rusticola L.), a medium-small wading bird hunted as game in many Eurasian countries, is considered one of the best meats for culinary purposes. Since the nutritional composition of Eurasian woodcock meat has not yet been reported, we decided to determine the nutritional profile of S. rusticola meat. Macronutrient components (proteins, lipids and fatty acids) were determined, as well as free and total amino acids, and compared with those of the common pheasant. Eurasian woodcock meat contains high levels of proteins and essential amino acids. The levels of unsaturated fatty acids represent a great contribution to the total lipid amount. Among polyunsaturated fatty acids, linoleic acid (C18:2, n-6) is the major essential fatty acid. Finally, we report the characterization of myoglobin (Mb) from Eurasian woodcock. The data revealed that meat from this bird could be a good source of quality raw proteins because of its amino acid composition, and it had a low lipid content. On the other hand, Mb characterization might be of benefit to the meat industry, by providing useful information for the determination of species-specific differences in meat from birds. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Change in diel catchability of young-of-year yellow perch associated with establishment of dreissenid mussels

Science.gov (United States)

Stapanian, Martin A.; Kocovsky, Patrick M.; Adams, Jean V.

2009-01-01

1. Non-native mussels have increased water clarity in many lakes and streams in North America and Europe. Diel variation in catchability of some fish species has been linked to visibility during survey trawls (used to measure escapement). 2. Water clarity increased in nearshore areas of western Lake Erie by the early 1990s, following passage of legislation in 1972 to improve water quality (e.g. reduce phosphorus loading) and the invasion of dreissenid mussels (Dreissena spp.) beginning in 1987. 3. We hypothesised that increased water clarity in Lake Erie resulted in decreased catchability of young-of-year (age-0) yellow perch (Perca flavescens Mitchill) during daylight compared to during night. We used a two-tiered modelling approach to test this hypothesis on the ratio (R) of catch per hour (CPH) during night to CPH during daylight in bottom trawl surveys conducted during 1961-2005. 4. First, we examined seven a priori models. The first model, the 'null' model, represented no change in R over time. Three more models tested whether the timing of the change in R was associated with passage of water quality legislation only, dreissenids only (two-period models) and both legislation and dreissenids (three-period models). Three additional models included a 3-year lag before the effects of legislation, dreissenids or both occurred. Secondly, all possible two- and three-period models with a minimum of 2 years per time period were explored a posteriori. The a posteriori procedure determined the temporal transitions to higher R that were best supported by the data, without regard to a priori hypotheses. 5. Night CPH was greater than daylight CPH in 3 of 11 years during 1961-72, in 10 of 15 years during 1973-87, and in 14 of 18 years during 1988-2005. During 1991-2005 night CPH exceeded daylight CPH in all years except one, and night CPH was more than twice daylight CPH in 10 years during this period. 6. The best a priori model had two periods, with a break between 1990 and

Beyond frontiers: Ancient Rome and the Eurasian trade networks

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Marco Galli

2017-01-01

Full Text Available During the second half of the 19th century, the Roman Empire was already considered one of the key players inside the Eurasian networks. This research focuses on four relevant points. From a historiographical perspective, the reconstruction of the trading routes represented a central theme in the history of the relationship between the Roman Empire and the Far East. Imagining a plurality of itineraries and combinations of overland and sea routes, it is possible to reconstruct a complex reality in which the Eurasian networks during the Early Roman Empire developed. As far as economics is concerned, new documentation demonstrates the wide range and the extraordinary impact of the Eastern products on Roman markets. A final focus on the process of Chinese silk unravelling and reweaving provides an important clue on how complex and absolutely not mono-directional were the interactions and the exchanges in the Eurasian networks during the first centuries of the Roman Empire.

Mercury in various tissues of fish caught downstream of a wood pulp factory in the Kammerfoss River, South Norway

International Nuclear Information System (INIS)

Steinnes, E.; Haastein, T.; Norheim, G.; Froeslie, A.

1976-01-01

The mercury content of perch (Perca fluviatilis) and brown trout (Salmo trutta) was studied during a 5-year period after the ban on phenyl mercury in 1970. Muscular concentrations of about 1μg Hg/g were found, compared with 3-6μg Hg/g found in 1968. Organ distribution studies indicated that high concentrations of mercury may be found in the liver and kidney of fish exposed to high mercury pollution. (author)

Evaluating fishery rehabilitation under uncertainty: A bioeconomic analysis of quota management for the Green Bay yellow perch fishery

Science.gov (United States)

Johnson, B.L.; Milliman, S.R.; Bishop, R.C.; Kitchell, J.F.

1992-01-01

The fishery for yellow perch Perca flavescens in Green Bay, Lake Michigan, is currently operating under a rehabilitation plan based on a commercial harvest quota. We developed a bioeconomic computer model that included links between population density and growth, recruitment, and fishing effort for this fishery. Random variability was included in the stock-recruitment relation and in a simulated population assessment. We used the model in an adaptive management framework to evaluate the effects of the rehabilitation plan on both commercial and sport fisheries and to search for ways to improve the plan. Results indicate that the current quota policy is a member of a set of policies that would meet most management goals and increase total value of the fishery. Sensitivity analyses indicate that this conclusion is robust over a wide range of biological conditions. We predict that commercial fishers will lose money relative to the baseline condition, but they may receive other benefits from the elimination of the common-property nature of the fishery. The prospect exists for managing variability in harvest and stock size and for maximizing economic returns in the fishery, but more information is required, primarily on sportfishing effort dynamics and angler preferences. Stock-recruitment relations, density dependence of growth, and dynamics of sportfishing effort are the primary sources of uncertainty limiting the precision of our predictions. The current quota policy is about as good as other policies at reducing this uncertainty and appears, overall, to be one of the best choices for this fishery. The analytical techniques used in this study were primarily simple, heuristic approaches that could be easily transferred to other studies.

Russian neo-revisionist strategy and the Eurasian Project

Directory of Open Access Journals (Sweden)

Ruslan Dzarasov

2017-03-01

Full Text Available The article is focused on the real meaning of the Eurasian Integration Project for East–West relations. The author departs from Sakwa’s treatment of Russian strategy as neo-revisionist. It does not aspire to change the current world order while trying to make the West observe its national interests within the existing framework. This perspective is treated in the article from the standpoint of world-systems analysis. The Eurasian Project is understood as a reaction of the Russian state to the failure of the neoliberal attempt to integrate into the world economy and the international security system. The two great trade mega-unions—the Trans-Pacific Partnership (TPP and the Trans-Atlantic Partnership—are seen as geoeconomic bolt clamps, which put Russia under enormous pressure. The Russian strategy in the Ukrainian and Syrian crises is designed to find the way out of strategic isolation. The Eurasian Union is expected by the Russian ruling elite to be an important tool to forestall the isolation of the country and secure her economic, military and international security.

Fins coloration of perch in relation to external activity concentration of radionuclides

Energy Technology Data Exchange (ETDEWEB)

Yegoreichenkov, E.; Pryakhin, E. [Urals Research Center for Radiation Medicine (Russian Federation); Rudolfsen, G. [Norwegian Radiation Protection Authority and University of Tromsoe (Norway)

2014-07-01

The Techa River is significantly polluted by radionuclides. This time the content of {sup 90}Sr varies from 5 Bq/l in water of lower Techa to 40 Bq/l in higher Techa, and the concentration of {sup 137}Cs fluctuates from background content to 0,5 Bq/l, and tritium from 100 Bq/l to 450 Bq/l. Miass River are not polluted in the same extent. The perch in these rivers are suitable for examine the potential effect of environmental perturbation on carotenoid based coloration. As vertebrates could not produce carotenoids themselves, and would use more carotenoids due to oxidative stress when exposed radiation, we hypothesized that fish caught in upper part of Techa River will be more pale than fish from lower part and the control river Miass. We used a cost effective method to estimate coloration by photographing the fins in standardized setting. The measuring of fish fins as performed under standardized condition by Adobe Photoshop software in color spaces CIE 1976 L*a*b* and sRGB IEC61966-2.1 was used. In sRGB color space the values of Red, Green, Blue channels were measured and an average wave length was calculated as a function of three elementary light streams of different intensity, appeared as reflection from a fin. In L*a*b color space the values of *a and *b channels shows the position of a color in a color space. To evaluate the red color of a perch fin the most usable channel is the *a channel which shows the position of the color on the red-green axis. Due to low sample size we pooled males and females in our analysis. We used three different station in the Techa: RT-1 in the higher Techa, RT-2 in the middle Techa, and RT-3 in lower Techa. As a control group was taken the fish from Miass river (RM station). Our results shows that perch from RT-3 (570.7 nm) significantly differ in coloration from the perch from RT-2 and RT-1 (p=0.00001 and p=0.0014 respectively, hereinafter used Kruskal-Wallis rank sum test with Nemenyi-Damico-Wolfe-Dunn test as post

Effects of dressing and cooking on DDT concentrations in certain fish from Lake Michigan

Science.gov (United States)

Reinert, Robert E.; Stewart, Donald; Seagran, Harry L.

1972-01-01

Concentrations of DDT residues were highest in parts of the body with the highest oil content in four species of fish from Lake Michigan: yellow perch (Perca flavescens), bloater (Coregonus hoyi), lake trout (Salvelinus namaycush), and coho salmon (Oncorhynchus kisutch). Dressing reduced the DDT residues and oil content by more than 90% in yellow perch but had little effect in the other three species. The concentration of DDT residues in bloaters was changed little by smoking but was reduced 64–72% by other methods of cooking: from 8.0 ppm (raw) to 2.2 ppm after frying in corn oil; from 10.7 to 3.9 ppm after frying in lard; and from 9.1 to 3.2 ppm after broiling. The concentration of DDT residues in fillets of yellow perch changed only from 0.3 ppm (raw) to 0.4 or 0.5 ppm after baking, frying, or broiling.

Strontium and zinc concentrations in otoliths of common fish species in the northern Baltic Sea

Energy Technology Data Exchange (ETDEWEB)

Lill, J.-O., E-mail: jlill@abo.fi [Accelerator Laboratory, Turku PET Centre, Åbo Akademi University, Porthansgatan 3, FI-20500 Turku (Finland); Himberg, M. [Laboratory of Aquatic Pathobiology, Husö Biological Station, Environmental and Marine Biology, Department of Biosciences, Åbo Akademi University, Artillerigatan 6, FI-20520 Turku (Finland); Harju, L.; Ek, P. [Analytical Chemistry, Department of Chemical Engineering, Åbo Akademi University, Biskopsgatan 8, FI-20500 Turku (Finland); Lindroos, A. [Geology and Mineralogy, Department of Natural Sciences, Åbo Akademi University, Domkyrkotorget, FI-20500 Turku (Finland); Wiklund, T. [Laboratory of Aquatic Pathobiology, Husö Biological Station, Environmental and Marine Biology, Department of Biosciences, Åbo Akademi University, Artillerigatan 6, FI-20520 Turku (Finland); Gunnelius, K.; Smått, J.-H. [Physical Chemistry, Department of Natural Sciences, Åbo Akademi University, Porthansgatan 3, FI-20500 Turku (Finland); Heselius, S.-J. [Accelerator Laboratory, Turku PET Centre, Åbo Akademi University, Porthansgatan 3, FI-20500 Turku (Finland); Hägerstrand, H. [Laboratory of Aquatic Pathobiology, Husö Biological Station, Environmental and Marine Biology, Department of Biosciences, Åbo Akademi University, Artillerigatan 6, FI-20520 Turku (Finland)

2014-01-01

Otoliths of perch (Perca fluviatilis), pike (Esox lucius) and European whitefish (Coregonus lavaretus) caught at different locations in the northern Baltic Sea along the Finnish west coast and at some rivers and lakes were subjected to elemental analyses with particle induced X-ray emission and laser ablation inductively coupled plasma mass spectrometry. The strontium concentration in otoliths from whitefish (∼3300 μg/g) was 2–3 times higher than that of perch and pike (∼1400 μg/g), while within species the strontium concentration of otoliths from fish caught at different locations was in the same range. The strontium concentrations were lowest in fish from the lakes (∼450 μg/g). Whitefish otoliths contained more zinc (∼60 μg/g) than those of pike (∼30 μg/g), while the zinc concentration in perch otoliths were below the detection limit. No spatial intraspecies variations in zinc concentrations were observed. X-ray diffraction showed that the otoliths consisted of aragonite solely.

Strontium and zinc concentrations in otoliths of common fish species in the northern Baltic Sea

International Nuclear Information System (INIS)

Lill, J.-O.; Himberg, M.; Harju, L.; Ek, P.; Lindroos, A.; Wiklund, T.; Gunnelius, K.; Smått, J.-H.; Heselius, S.-J.; Hägerstrand, H.

2014-01-01

Otoliths of perch (Perca fluviatilis), pike (Esox lucius) and European whitefish (Coregonus lavaretus) caught at different locations in the northern Baltic Sea along the Finnish west coast and at some rivers and lakes were subjected to elemental analyses with particle induced X-ray emission and laser ablation inductively coupled plasma mass spectrometry. The strontium concentration in otoliths from whitefish (∼3300 μg/g) was 2–3 times higher than that of perch and pike (∼1400 μg/g), while within species the strontium concentration of otoliths from fish caught at different locations was in the same range. The strontium concentrations were lowest in fish from the lakes (∼450 μg/g). Whitefish otoliths contained more zinc (∼60 μg/g) than those of pike (∼30 μg/g), while the zinc concentration in perch otoliths were below the detection limit. No spatial intraspecies variations in zinc concentrations were observed. X-ray diffraction showed that the otoliths consisted of aragonite solely

Precision of four otolith techniques for estimating age of white perch from a thermally altered reservoir

Science.gov (United States)

Snow, Richard A.; Porta, Michael J.; Long, James M.

2018-01-01

The White Perch Morone americana is an invasive species in many Midwestern states and is widely distributed in reservoir systems, yet little is known about the species' age structure and population dynamics. White Perch were first observed in Sooner Reservoir, a thermally altered cooling reservoir in Oklahoma, by the Oklahoma Department of Wildlife Conservation in 2006. It is unknown how thermally altered systems like Sooner Reservoir may affect the precision of White Perch age estimates. Previous studies have found that age structures from Largemouth Bass Micropterus salmoides and Bluegills Lepomis macrochirus from thermally altered reservoirs had false annuli, which increased error when estimating ages. Our objective was to quantify the precision of White Perch age estimates using four sagittal otolith preparation techniques (whole, broken, browned, and stained). Because Sooner Reservoir is thermally altered, we also wanted to identify the best month to collect a White Perch age sample based on aging precision. Ages of 569 White Perch (20–308 mm TL) were estimated using the four techniques. Age estimates from broken, stained, and browned otoliths ranged from 0 to 8 years; whole‐view otolith age estimates ranged from 0 to 7 years. The lowest mean coefficient of variation (CV) was obtained using broken otoliths, whereas the highest CV was observed using browned otoliths. July was the most precise month (lowest mean CV) for estimating age of White Perch, whereas April was the least precise month (highest mean CV). These results underscore the importance of knowing the best method to prepare otoliths for achieving the most precise age estimates and the best time of year to obtain those samples, as these factors may affect other estimates of population dynamics.

Perched-Water Evaluation for the Deep Vadose Zone Beneath the B, BX, and BY Tank Farms Area of the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J.; Oostrom, Martinus; Carroll, KC; Chronister, Glen B.

2013-06-28

Perched-water conditions have been observed in the vadose zone above a fine-grained zone that is located a few meters above the water table within the B, BX, and BY Tank Farms area. The perched water contains elevated concentrations of uranium and technetium-99. This perched-water zone is important to consider in evaluating the future flux of contaminated water into the groundwater. The study described in this report was conducted to examine the perched-water conditions and quantitatively evaluate 1) factors that control perching behavior, 2) contaminant flux toward groundwater, and 3) associated groundwater impact.

Small fish use the hypoxic pelagic zone as a refuge from predators.

Czech Academy of Sciences Publication Activity Database

Vejřík, Lukáš; Matějíčková, Ivana; Jůza, Tomáš; Frouzová, Jaroslava; Seďa, Jaromír; Blabolil, Petr; Ricard, Daniel; Vašek, Mojmír; Kubečka, Jan; Říha, Milan; Čech, Martin

2016-01-01

Roč. 61, č. 6 (2016), s. 899-913 ISSN 0046-5070 R&D Projects: GA MŠk(CZ) EE2.3.20.0204; GA MŠk(CZ) 7F14316; GA ČR GP206/09/P266; GA ČR(CZ) GA15-24309S; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : hypoxia * Perca fluviatilis * perch * predator avoidance * zooplankton Subject RIV: DA - Hydrology ; Limnology Impact factor: 3.255, year: 2016

Methods to assess impacts on Hudson River white perch: report for the period October 1, 1978 to September 30, 1979

International Nuclear Information System (INIS)

Barnthouse, L.W.; Kirk, B.L.; Kumar, K.D.; Van Winkle, W.; Vaughan, D.S.

1980-06-01

This report is a brief description of the work done on the NRC project entitled 'Methods to Assess Impacts on Hudson River White Perch' October 1, 1978 to September 30, 1979. Accounts of special studies of white perch entrainment at Hudson River power plants, of density-dependent growth in the Hudson River white perch population, and of data on the white perch populations of the Delaware and Chesapeake systems were performed. Complete accounts of these special studies are included in this report. During this period, a final draft topical report entitled 'Evaluation of Impingement Losses of White Perch at the Indian Point Nuclear Station and Other Hudson River Power Plants' (NUREG/CR-1100) was completed

The Effect of Cooled Perches on Immunological Parameters of Caged White Leghorn Hens during the Hot Summer Months.

Directory of Open Access Journals (Sweden)

Rebecca A Strong

Full Text Available The objective of this study was to determine if thermally cooled perches improve hen immunity during hot summer. White Leghorn pullets at 16 week of age were randomly assigned to 18 cages of 3 banks at 9 hens per cage. Each bank was assigned to 1 of the 3 treatments up to 32 week of age: 1 thermally cooled perches, 2 perches with ambient air, and 3 cages without perches. Hens were exposed to natural ambient temperatures from June through September 2013 in Indiana with a 4 h acute heat episode at 27.6 week of age. The packed cell volume, heterophil to lymphocyte (H/L ratio, plasma concentrations of total IgG, and cytokines of interleukin-1β and interleukin-6, plus lipopolysaccharide-induced tumor necrosis factor-α factor were measured at both 27.6 and 32 week of age. The mRNA expressions of these cytokines, toll-like receptor-4, and inducible nitric oxide synthase were also examined in the spleen of 32 week-old hens. Except for H/L ratio, thermally cooled perches did not significantly improve currently measured immunological indicators. These results indicated that the ambient temperature of 2013 summer in Indiana (24°C, 17.1 to 33.1°C was not high enough and the 4 h heat episode at 33.3°C (32 to 34.6°C was insufficient in length to evoke severe heat stress in hens. However, cooled perch hens had a lower H/L ratio than both air perch hens and control hens at 27.6 week of age and it was still lower compared to control hens (P < 0.05, respectively at 32 week of age. The lowered H/L ratio of cooled perch hens may suggest that they were able to cope with acute heat stress more effectively than control hens. Further studies are needed to evaluate the effectiveness of thermally cooled perches on hen health under higher ambient temperatures.

Initial opening of the Eurasian Basin, Arctic Ocean

Directory of Open Access Journals (Sweden)

Kai Berglar

2016-10-01

Full Text Available Analysis of the transition from the NE Yermak Plateau into the oceanic Eurasian Basin sheds light on the Paleocene formation of this Arctic basin. Newly acquired multichannel seismic data with a 3600 m long streamer shot during ice-free conditions enables the interpretation of crustal structures. Evidence is provided that no major compressional deformation affected the NE Yermak Plateau. The seismic data reveal that the margin is around 80 km wide and consists of rotated fault blocks, major listric normal faults, and half-grabens filled with syn-rift sediments. Taking into account published magnetic and gravimetric data, this setting is interpreted as a rifted continental margin, implying that the NE Yermak Plateau is of continental origin. The transition from the Yermak Plateau to the oceanic Eurasian Basin might be located at a prominent basement high, probably formed by exhumed mantle. In contrast to the Yermak Plateau margin, the North Barents Sea continental margin shows a steep continental slope with a relatively abrupt transition to the oceanic domain. Based on one composite seismic line, it is speculated that the initial opening direction of the Eurasian Basin in the Arctic Ocean was highly oblique to the present day seafloor spreading direction.

Perch availability and ground cover: factors that may constitute ...

African Journals Online (AJOL)

1996-02-21

Feb 21, 1996 ... pale chanting goshawks occupied areas where perch density (16 natural and 122 artificial/25 hal was signifi- ... sal and cooperative breeding in pale chanting goshawk families. ...... fortunes in the white-fronted bee-eater.

Occurrence of parasites of the genus Eustrongylides spp. (Nematoda: Dioctophymatidae in fish caught in Trasimeno lake, Italy

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Raffaella Branciari

2016-11-01

Full Text Available Eustrongylides spp. is considered a freshwater fish zoonotic nematode. In the present study, the prevalence of Eustrongylides spp. in six edible fish (European perch - Perca fluviatilis, goldfish - Carassius auratus, largemouth black bass - Micropterus salmoides, tench- Tinca tinca, carp - Cyprinus carpio and sand smelt - Atherina boyeri of Trasimeno lake was surveyed. The investigations were conducted from October 2014 to September 2015 and 384 specimens per species for each season were caught in Trasimeno lake and examined for the presence of larvae in the abdominal cavity and muscle. The presence of nematodes in the abdominal cavity and musculature was revealed in three fish species. The prevalence of Eustrongylides spp. infection was 6.84, 1.89 and 0.13% in perch, largemouth black bass and sand smelt, respectively. The number of parasites per fish was only one in largemouth black bass and sand smelt and ranged from one up to three in perch. This study states that the European perch, largemouth black bass and sand smelt of Trasimeno lake are infected with zoonotic parasites; therefore, food business operators have to take appropriate measures to guarantee the health of consumers.

Flavonoid variation in Eurasian Sedum and Sempervivum

NARCIS (Netherlands)

Stevens, J.F; 't Hart, H; Elema, E.T; Bolck, A

Flavonoids from vegetative parts of 29 species of Eurasian Sedum, Sedum meyeri-johannis from central East Africa, 34 species of Sempervivum, and Jovibarba heuffelii have been identified after acid hydrolysis. Ten flavonoid aglycones were detected, i.e. kaempferol, herbacetin, sexangularetin,

The diet of reservoir perch before, during and after establishment of non-native tubenose goby

Czech Academy of Sciences Publication Activity Database

Všetičková, Lucie; Mikl, Libor; Adámek, Zdeněk; Prášek, Václav; Roche, Kevin Francis; Jurajda, Pavel

2018-01-01

Roč. 419, č. 419 (2018), č. článku 4. ISSN 1961-9502 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : dietary shift * food preference * Gobiidae * invasive species * Perca fluviatilis * piscivore diet Subject RIV: EG - Zoology Impact factor: 1.217, year: 2016

Perch Selection by Three Cooccurring Species of Celithemis (Odonata: Libellulidae: Testing for a Competitive Hierarchy among Similar Species

Directory of Open Access Journals (Sweden)

Wade B. Worthen

2016-01-01

Full Text Available In many communities of perching dragonflies (Odonata: Libellulidae, a size-dependent competitive hierarchy creates a positive relationship between male body size and perch height. We tested for this pattern among three similar-sized species: Celithemis elisa, C. fasciata, and C. ornata. Males were caught and photographed from May to July 2015 at Ashmore Heritage Preserve, Greenville County, SC, USA, and perch heights and perch distance to open water were measured. Five indices of body size were measured with ImageJ software: abdomen length, forewing length, hindwing length, area of forewing, and area of hindwing. Celithemis fasciata was significantly larger than the other two species for all five anatomical characters and used perches that were significantly taller and closer to open water than the other species, though these differences changed over the summer. Aggressive interactions between and within species were tallied and compared to expected distributions based on mean relative abundances derived from hourly abundance counts. Patterns of interspecific aggression were also consistent with a size-dependent hierarchy: the large C. fasciata was attacked less frequently, and the small C. ornata more frequently, than predicted by their relative abundances. We conclude that even small differences in body size may contribute to niche partitioning in perch selection.

How might the North American ice sheet influence the northwestern Eurasian climate?

Science.gov (United States)

Beghin, P.; Charbit, S.; Dumas, C.; Kageyama, M.; Ritz, C.

2015-10-01

It is now widely acknowledged that past Northern Hemisphere ice sheets covering Canada and northern Europe at the Last Glacial Maximum (LGM) exerted a strong influence on climate by causing changes in atmospheric and oceanic circulations. In turn, these changes may have impacted the development of the ice sheets themselves through a combination of different feedback mechanisms. The present study is designed to investigate the potential impact of the North American ice sheet on the surface mass balance (SMB) of the Eurasian ice sheet driven by simulated changes in the past glacial atmospheric circulation. Using the LMDZ5 atmospheric circulation model, we carried out 12 experiments under constant LGM conditions for insolation, greenhouse gases and ocean. In these experiments, the Eurasian ice sheet is removed. The 12 experiments differ in the North American ice-sheet topography, ranging from a white and flat (present-day topography) ice sheet to a full-size LGM ice sheet. This experimental design allows the albedo and the topographic impacts of the North American ice sheet onto the climate to be disentangled. The results are compared to our baseline experiment where both the North American and the Eurasian ice sheets have been removed. In summer, the sole albedo effect of the American ice sheet modifies the pattern of planetary waves with respect to the no-ice-sheet case, resulting in a cooling of the northwestern Eurasian region. By contrast, the atmospheric circulation changes induced by the topography of the North American ice sheet lead to a strong decrease of this cooling. In winter, the Scandinavian and the Barents-Kara regions respond differently to the American ice-sheet albedo effect: in response to atmospheric circulation changes, Scandinavia becomes warmer and total precipitation is more abundant, whereas the Barents-Kara area becomes cooler with a decrease of convective processes, causing a decrease of total precipitation. The gradual increase of the

Rapid area change in pitch-up manoeuvres of small perching birds.

Science.gov (United States)

Polet, D T; Rival, D E

2015-10-26

Rapid pitch-up has been highlighted as a mechanism to generate large lift and drag during landing manoeuvres. However, pitching rates had not been measured previously in perching birds, and so the direct applicability of computations and experiments to observed behaviour was not known. We measure pitch rates in a small, wild bird (the black-capped chickadee; Poecile atricapillus), and show that these rates are within the parameter range used in experiments. Pitching rates were characterized by the shape change number, a metric comparing the rate of frontal area increase to acceleration. Black-capped chickadees increase the shape change number during perching in direct proportion to their total kinetic and potential energy at the start of the manoeuvre. The linear relationship between dissipated energy and shape change number is in accordance with a simple analytical model developed for two-dimensional pitching and decelerating airfoils. Black-capped chickadees use a wing pitch-up manoeuvre during perching to dissipate energy quickly while maintaining lift and drag through rapid area change. It is suggested that similar pitch-and-decelerate manoeuvres could be used to aid in the controlled, precise landings of small manoeuvrable air vehicles.

Robust post-stall perching with a simple fixed-wing glider using LQR-Trees

International Nuclear Information System (INIS)

Moore, Joseph; Cory, Rick; Tedrake, Russ

2014-01-01

Birds routinely execute post-stall maneuvers with a speed and precision far beyond the capabilities of our best aircraft control systems. One remarkable example is a bird exploiting post-stall pressure drag in order to rapidly decelerate to land on a perch. Stall is typically associated with a loss of control authority, and it is tempting to attribute this agility of birds to the intricate morphology of the wings and tail, to their precision sensing apparatus, or their ability to perform thrust vectoring. Here we ask whether an extremely simple fixed-wing glider (no propeller) with only a single actuator in the tail is capable of landing precisely on a perch from a large range of initial conditions. To answer this question, we focus on the design of the flight control system; building upon previous work which used linear feedback control design based on quadratic regulators (LQR), we develop nonlinear feedback control based on nonlinear model-predictive control and ‘LQR-Trees’. Through simulation using a flat-plate model of the glider, we find that both nonlinear methods are capable of achieving an accurate bird-like perching maneuver from a large range of initial conditions; the ‘LQR-Trees’ algorithm is particularly useful due to its low computational burden at runtime and its inherent performance guarantees. With this in mind, we then implement the ‘LQR-Trees’ algorithm on real hardware and demonstrate a 95 percent perching success rate over 147 flights for a wide range of initial speeds. These results suggest that, at least in the absence of significant disturbances like wind gusts, complex wing morphology and sensing are not strictly required to achieve accurate and robust perching even in the post-stall flow regime. (papers)

Are high perches in the blackcap Sylvia atricapilla song or listening posts? A sound transmission study

DEFF Research Database (Denmark)

Mathevon, Nicolas; Dabelsteen, Torben; Blumenrath, Sandra Helene

2005-01-01

Birds often sing from high perches referred to as song posts. However, birds also listen and keep a lookout from these perches. We used a sound transmission experiment to investigate the changes for receiving and sending conditions that a territorial songbird may experience by moving upwards...

Haematology and Serum Biochemistry Parameters and Variations in the Eurasian Beaver (Castor fiber).

Science.gov (United States)

Girling, Simon J; Campbell-Palmer, Roisin; Pizzi, Romain; Fraser, Mary A; Cracknell, Jonathan; Arnemo, Jon; Rosell, Frank

2015-01-01

Haematology parameters (N = 24) and serum biochemistry parameters (N = 35) were determined for wild Eurasian beavers (Castor fiber), between 6 months - 12 years old. Of the population tested in this study, N = 18 Eurasian beavers were from Norway and N = 17 originating from Bavaria but now living extensively in a reserve in England. All blood samples were collected from beavers via the ventral tail vein. All beavers were chemically restrained using inhalant isoflurane in 100% oxygen prior to blood sampling. Results were determined for haematological and serum biochemical parameters for the species and were compared between the two different populations with differences in means estimated and significant differences being noted. Standard blood parameters for the Eurasian beaver were determined and their ranges characterised using percentiles. Whilst the majority of blood parameters between the two populations showed no significant variation, haemoglobin, packed cell volume, mean cell haemoglobin and white blood cell counts showed significantly greater values (pbeavers or between sexually immature (beavers in the animals sampled. With Eurasian beaver reintroduction encouraged by legislation throughout Europe, knowledge of baseline blood values for the species and any variations therein is essential when assessing their health and welfare and the success or failure of any reintroduction program. This is the first study to produce base-line blood values and their variations for the Eurasian beaver.

The Eurasian Dry Grassland Group (EDGG in 2016–2017

Directory of Open Access Journals (Sweden)

Venn Stephen

2018-06-01

Full Text Available This report summarizes the activities and achievements of the Eurasian Dry Grassland Group (EDGG from mid-2016 through to the end of 2017. During this period, the 13th Eurasian Grassland Conference took place in Sighişoara, Romania, and the 14th conference was held in Riga, Latvia. The 10th EDGG Field Workshop on Biodiversity patterns across a precipitation gradient in the Central Apennine mountains was conducted in the Central Apennines, Italy, this time in addition to multi-scale sampling of vascular plants, bryophytes and lichens, also including one animal group (leaf hoppers. Apart from the quarterly issues of its own electronic journal (Bulletin of the Eurasian Dry Grassland Group, EDGG also finalised five grassland-related Special Features/Issues during the past 1.5 years in the following international journals: Applied Vegetation Science, Biodiversity and Conservation, Phytocoenologia, Tuexenia and Hacquetia. Beyond that, EDGG facilitated various national and supra-national vegetationplot databases of grasslands and established its own specialised database for standardised multi-scale plot data of Palaearctic grasslands (GrassPlot.

FORMATION OF THE PUBLIC PROCUREMENT SYSTEM IN THE EURASIAN ECONOMIC UNION

Directory of Open Access Journals (Sweden)

Vladimir Vladimirovich Savchenko

2016-01-01

Full Text Available The study revealed aspects of the organization of public procurement in the Eurasian Economic Union, outlines approaches to the study of the role of procurement management system in the formation of industrial capabilities to carry out competition in the market activity. The article assesses the eff ectiveness of the fi nancial mechanism in the public procurement system and discusses the dynamics of the procurement process and its features by using the most common competitive methods of procurement. The purpose / goal. The aim of the article is to identify further ways to optimize public procurement system in the Eurasian Economic Union. Tasks article. Develop an acceptable doctrinal foundations for today system of organization of public procurement in the Eurasian Economic Union. Methodology. The author began his research with the setting and the formation of the research objectives. The author defi ned the subject of the study, prepared by the empirical basis of the study. In terms of methodology, this work is an analytical and historical overview of the economic and socio-political processes taking place at the level of individual countries, regions of the world, and the world economy as a whole. Results. This article provides practical recommendations that can be used to create an eff ective integrated system of public procurement in the Eurasian Economic Union.

Pulmonary adiaspiromycosis in the Eurasian beaver (Castor fiber) inhabiting Poland.

Science.gov (United States)

Dolka, I; Giżejewska, A; Giżejewski, Z; Kołodziejska-Lesisz, J; Kluciński, W

2017-09-26

Adiaspiromycosis is a rare fungal infection caused by saprophytic fungi Emmonsia spp. (type Ascomycota) occurring especially in small free-living mammals. The aim of this study was to evaluate the occurrence of histopathological lesions asscociated with adiaspiromycosis in the Eurasian beaver inhabiting Poland. In order to evaluate the presence of natural adiaspiromycosis we systematically investigated beaver populations from north-eastern Poland for adiaspores in the lungs. This study reveals for the first time the presence of pulmonary adiaspiromycosis of Eurasian beaver in Poland. As far as we know, there is no published data regarding pulmonary adiaspiromycosis in human patients in Poland.

ESTABLISHING THE PAN-EURASIAN EXPERIMENT (PEEX LAND-ATMOSPHERE IN SITU OBSERVATION NETWORK ACROSS THE NORTHERN EURASIAN ARCTIC-BOREAL REGIONS ‒ INTRODUCTION TO THE RUSSIAN STATIONS’ METADATA ENQUIRY

Directory of Open Access Journals (Sweden)

H. K. Lappalainen

2017-01-01

Full Text Available Pan-Eurasian Experiment (PEEX initiative (https://www.atm.helsinki.fi/peex/, initiated in 2012, is an international, multidisciplinary, multiscale program focused on solving interlinked global challenges influencing societies in the Northern Eurasian region and in China. As a part of the program, PEEX is aimed to establish an in situ observation network, which would cover environments from the Arctic coastal regions, tundra to boreal forests, from pristine to urban megacities. The PEEX network will be based on two components: (i the existing stations activities and (ii establishing new stations. The upgrading plans of the existing stations as well as the new stations will be based on a SMEAR (Stations for Measuring Earth surface ‒ Atmosphere Relations concept. The development of the coordinated, comprehensive PEEX observation network is contributing to the sustainable development of the Northern Eurasian regions. It is aimed at providing quantified information on climate relevant variables for the research communities and for constructing services, such as early warning systems, for the society.

Chad Genetic Diversity Reveals an African History Marked by Multiple Holocene Eurasian Migrations.

Science.gov (United States)

Haber, Marc; Mezzavilla, Massimo; Bergström, Anders; Prado-Martinez, Javier; Hallast, Pille; Saif-Ali, Riyadh; Al-Habori, Molham; Dedoussis, George; Zeggini, Eleftheria; Blue-Smith, Jason; Wells, R Spencer; Xue, Yali; Zalloua, Pierre A; Tyler-Smith, Chris

2016-12-01

Understanding human genetic diversity in Africa is important for interpreting the evolution of all humans, yet vast regions in Africa, such as Chad, remain genetically poorly investigated. Here, we use genotype data from 480 samples from Chad, the Near East, and southern Europe, as well as whole-genome sequencing from 19 of them, to show that many populations today derive their genomes from ancient African-Eurasian admixtures. We found evidence of early Eurasian backflow to Africa in people speaking the unclassified isolate Laal language in southern Chad and estimate from linkage-disequilibrium decay that this occurred 4,750-7,200 years ago. It brought to Africa a Y chromosome lineage (R1b-V88) whose closest relatives are widespread in present-day Eurasia; we estimate from sequence data that the Chad R1b-V88 Y chromosomes coalesced 5,700-7,300 years ago. This migration could thus have originated among Near Eastern farmers during the African Humid Period. We also found that the previously documented Eurasian backflow into Africa, which occurred ∼3,000 years ago and was thought to be mostly limited to East Africa, had a more westward impact affecting populations in northern Chad, such as the Toubou, who have 20%-30% Eurasian ancestry today. We observed a decline in heterozygosity in admixed Africans and found that the Eurasian admixture can bias inferences on their coalescent history and confound genetic signals from adaptation and archaic introgression. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Using consumption rate to assess potential predators for biological control of white perch

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Gosch N.J.C.

2011-08-01

Full Text Available Control of undesirable fishes is important in aquatic systems, and using predation as a tool for biological control is an attractive option to fishery biologists. However, determining the appropriate predators for biological control is critical for success. The objective of this study was to evaluate the utility of consumption rate as an index to determine the most effective predators for biological control of an invasive fish. Consumption rate values were calculated for nine potential predators that prey on white perch Morone americana in Branched Oak and Pawnee reservoirs, Nebraska. The consumption rate index provided a unique and insightful means of determining the potential effectiveness of each predator species in controlling white perch. Cumulative frequency distributions facilitated interpretation by providing a graphical presentation of consumption rates by all individuals within each predator species. Largemouth bass Micropterus salmoides, walleye Sander vitreus and sauger S. canadensis were the most efficient white perch predators in both reservoirs; however, previous attempts to increase biomass of these predators have failed suggesting that successful biological control is unlikely using existing predator species in these Nebraska reservoirs.

Study of pike-perch (Sander lucioperca fishery from Razim Lake, Danube delta Romania

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CERNIȘENCU Irina

2018-05-01

Full Text Available The Razim Lake is a great part of the Danube Delta Biosphere Reserve (DDBR, with a surface of 54,000 ha. Fish fauna from Razim lake include pike-perch (Sander lucioperca as one of the main top predators of fish community, however ecological significance indicates accessory species, recedent as dominance, sometimes been subrecedent species like in 2011 and 2012 sampling, but constant species regarding frequency in sampling. Otherwise, pike-perch is an important value DDBR fishery species with an average of 5% in total catch, range 2-10%, from what Razim lake contributes with average 71%, range 41-95% in the 1960-2015 period. Razim Lake has been in average 13%, range 1-40% from total Razim lake catch, in the same period of time. Since in RBDD has been fishing up to 2000 fisherman, in Razim lake activated up to 500 fishermen, however nowadays number of fishermen was regulated at lower range. Catch data series shows a continuous stock decline trend, considered to be a consequences of habitat degradation and over-exploitation. Fish stock estimation in last 15 years (2001-2016 support the hypothesis of over-exploitation. Based on length frequency structure of landings, the growth and exploitation parameters have been estimated as well as the average biomass and the maximum sustainable yields for the Razim lake pike-perch stock. Recommendation concerning fisheries management towards sustainable fishing of pike-perch stock, as increasing of cod-end seine mesh size and decreasing of fishing effort regulation are outlined.

Effects of perched water on thermally driven moisture flow at the proposed Yucca Mountain repository for high-level waste

International Nuclear Information System (INIS)

Ofoegbu, G.I.; Bagtzoglou, A.C.; Green, R.T.; Muller, M.A.

1999-01-01

Numerical modeling was conducted to identify potential perched-water sites and examine the effects of perched water on thermally driven moisture flow at the proposed Yucca Mountain repository for high-level nuclear waste. It is demonstrated that perched-water zones may occur at two horizons on the up-dip side of faults such as the Ghost Dance Fault (GDF): in nonwelded volcanic strata [such as the Paintbrush Tuff nonwelded (PTn) stratigraphic unit], where juxtaposition of welded strata against nonwelded may constitute a barrier to lateral flow within the nonwelded strata; and in fractured horizons of underlying welded units [such as the Topopah Spring welded (TSw) unit] because of focused infiltration fed by overlying perched zones. The potential perched zones (PPZs) may contain perched water (which would flow freely into a well or opening) if infiltration rates are high enough. At lower infiltration rates, the PPZs contain only capillary-held water at relatively high saturations. Areas of the proposed repository that lie below PPZs are likely to experience relatively high percolation flux even if the PPZ contains only capillary-held water at high saturation. As a result, PPZs that contain only capillary-held water may be as important to repository performance as those that contain perched water. Thermal loading from emplaced waste in the repository is not likely to have an effect on PPZs located on adequate distance above the repository (such as in the PTn). As a result, such PPZs may be considered as permanent features of the environment. On the other hand, PPZs close to the repository depth (such as those that may occur in the TSw rock unit) would experience an initial period of spatial growth and increased saturation following waste emplacement. Thereafter, drying would begin at the repository horizon with perched-zone growth simultaneously above and below the repository. As a result, after the initial period of expansion, PPZs close to the repository horizon

Endoparasites of European perch Perca fluviatilis fry: role of spatial segregation

Czech Academy of Sciences Publication Activity Database

Kuchta, Roman; Čech, Martin; Scholz, Tomáš; Soldánová, Miroslava; Levron, Céline; Škoríková, Blanka

2009-01-01

Roč. 86, č. 1 (2009), s. 87-91 ISSN 0177-5103 R&D Projects: GA ČR GA524/08/0885; GA ČR GA206/06/1371; GA ČR GP206/09/P266; GA AV ČR KJB600960902; GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z60170517 Keywords : Acanthocephala * Cestoda * Nematoda Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.687, year: 2009

Eurasian golden jackal as host of canine vector-borne protists.

Science.gov (United States)

Mitková, Barbora; Hrazdilová, Kristýna; D'Amico, Gianluca; Duscher, Georg Gerhard; Suchentrunk, Franz; Forejtek, Pavel; Gherman, Călin Mircea; Matei, Ioana Adriana; Ionică, Angela Monica; Daskalaki, Aikaterini Alexandra; Mihalca, Andrei Daniel; Votýpka, Jan; Hulva, Pavel; Modrý, David

2017-04-14

Jackals are medium-sized canids from the wolf-like clade, exhibiting a unique combination of ancestral morphotypes, broad trophic niches, and close phylogenetic relationships with the wolf and dog. Thus, they represent a potential host of several pathogens with diverse transmission routes. Recently, populations of the Eurasian golden jackal Canis aureus have expanded into the Western Palaearctic, including most of Europe. The aim of our study was to examine Eurasian golden jackals from Romania, Czech Republic and Austria for a wide spectrum of vector-borne protists and to evaluate the role of this species as a reservoir of disease for domestic dogs and/or humans. Diagnostic polymerase chain reaction (PCR) DNA amplifications revealed 70% of jackals to be positive for Hepatozoon, 12.5% positive for piroplasms, and one individual positive for Leishmania infantum. Phylogenetic analyses of partial 18S rDNA sequences invariably placed sequenced isolates of Hepatozoon into the H. canis clade. For piroplasms, both the 18S and cox1 sequences obtained confirmed the presence of Babesia canis and "Theileria annae" in 5 and 2 individuals, respectively, providing the first records of these two piroplasmids in Eurasian golden jackals. A single animal from Dolj County (Romania) was PCR-positive for L. infantum, as confirmed also by sequencing of ITS1-5.8S. Apparently, expanding populations of jackals can play a significant role in spreading and maintaining new Babesia canis foci in Central Europe. The role of jackals in the epidemiology of "Theileria annae" and H. canis is probably similar to that of red foxes and should be taken into account in further research on these parasites. Also the presence of L. infantum deserves attention. Our study confirms that once established, the populations of Eurasian golden jackals constitute natural reservoirs for many canine vector-borne diseases, analogous to the role of the coyotes in North America.

Population morphological variation of the Nile perch (Lates niloticus ...

African Journals Online (AJOL)

use

The analysis clustered the Nile perch into two groups, which were found to be as characterised by earlier morphological description of this species and most probably are representatives of two distinct ... species of Lates niloticus as the specimens from Lakes ... (K), which is one factor that is considered when determining the ...

Impact of impingement on the Hudson River white perch population

International Nuclear Information System (INIS)

Barnthouse, L.W.; Van Winkle, W.

1980-01-01

The impact of power plant impingement on the 1974 and 1975 year classes of the Hudson River white perch population is assessed using a simple model derived from Ricker's theory of fisheries dynamics. The impact of impingement is expressed in the model as the conditional mortality rate, rather than as the more commonly used exploitation rate. Since the calculated impact is sensitive to errors in the estimation of population size and total mortality, ranges of probable values of these quantities are used to compute upper and lower bounds on the fractional reduction in abundance of each year class. Best estimates of abundance and mortality are used to compute the conditional impingement mortality rate separately for each plant and month. The results are used to assess the relative impacts of white perch impingement at six Hudson River power plants and to identify the seasons during which the impact is highest

Seasonal dynamics and life histories of pelagic cladocerans (Crustacea; Cladocera in an acid boreal lake

Directory of Open Access Journals (Sweden)

Jens Petter NILSSEN

2011-02-01

Full Text Available In the surveyed anthropogenic acidified Lake Gjerstadvann with pH ≈ 5.2 situated in southern Norway, spatial and temporal distribution of three characteristic planktonic cladocerans inhabiting acidified boreal biotopes, Bosmina longispina, Holopedium gibberum, and Diaphanosoma brachyurum, were studied over a period of one year. The major pelagic predator was Eurasian perch, Perca fluviatilis. The local perch probably balanced the cladoceran community and facilitated co-existence of all three species of cladocerans by removing significant portions of B. longispina, which could also be the case in similar types of boreal lakes. Invertebrate predators such as the dipteran larvae Chaoborus flavicans and carnivorous copepods did not seem to influence the cladoceran community. B. longispina was perennial, whereas both H. gibberum and D. brachyurum were recorded only during the ice-free period. The life cycle of these free-living pelagic species ranged from 2-3 in D. brachyurum, 3 in H. gibberum to approximately 6 annual generations in B. longispina. Wintering took place as resting eggs in D. brachyurum and H. gibberum, while B. longispina produced resting eggs in addition to an active planktonic stay. The warm water tolerant D. brachyurum was mainly distributed above the thermocline, whereas H. gibberum also inhabited deeper strata, and B. longispina most vertical strata of the lake. Maximum seasonal clutch volume of B. longispina coincided in time with peak in food abundance and may be a useful parameter to identify planktonic food availability in such lakes. Knowledge of the autecology and life history of species is fundamental for understanding ecosystem stress, such as anthropogenic acidification and recovery through liming or by natural causes. Seasonal depth isoplots combined with life history studies of commonly co-occurring cladoceran species from natural acid and anthropogenic acidified lakes on the Northern Hemisphere seem to be uncommon

Eurasian Economic Union: A Regional Economic Hegemony Initiative

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Serdar YILMAZ

2017-11-01

Full Text Available It can be assumed that international relations terminology has not mentioned enough about the significance of the Eurasian Economic Union in territorial as well as in economic terms during a period of growing geopolitical risks and high interdependence between the member countries and the rest. According to Kazakhstan’s President Nursultan Nazarbayev, it is truly difficult for states to overcome economic, political and security issues and therefore, states need to act together against the problems in a globalizing world by establishing regional and international organisations. This article thus examines the Eurasian Economic Union integration proces, which is driven by political and economic factors that consolidate regional security and create an effective economic system, whether it in the long term will become successful or not. The author also analyses the Kazakh economic and strategic interests in the region as well as the motivation, power and influence of other members in deepening the cooperation with international arena and the limits in the economic-security integration.

Salmonella and Vibrio cholerae in Nile perch ( Lates niloticus ...

African Journals Online (AJOL)

The Nile perch (Lates niloticus) industry in East Africa has suffered severe economic losses in the last few years due to failure to comply with the microbiological standards of European Union (E.U). Fresh and frozen products have been suspected to be contaminated with Salmonella and Vibrio cholerae. This has led to a ...

Whole body and egg amino acid composition of Nile perch, Lates ...

African Journals Online (AJOL)

Windows User

Nile perch (Lates niloticus) is a freshwater carnivorous fish and a couple of authors have ... relationship to the amino acid (AA) profile in fish because ... American catfish Rhamdia quelen (Meyer and Fracalossi,. 2005). ...... North Beach Western.

NHE-1 sequence and expression in toad, snake and fish red blood cells

DEFF Research Database (Denmark)

Thomsen, Steffen Nyegaard; Wang, Tobias; Kristensen, Torsten

Red blood cells (RBC) from reptiles appear not to express regulatory volume increase (RVI) upon shrinkage (Kristensen et al., 2008). In other vertebrates, the RVI response is primarily mediated by activation of the Na+/H+ exchanger (NHE-1) and we, therefore decided to investigate whether red cells...... of reptiles express a different NHE-1 that responds less to volume activation compared to other vertebrates or simply lack the Na+/H+ exchanger. Using various tissues from the ball python (Python regius), Cane toad (Bufo marinus) and European perch (Perca fluviatilis), cDNA libraries were created...

Biogenic volatile organic compound emissions from the Eurasian taiga: current knowledge and future directions

Energy Technology Data Exchange (ETDEWEB)

Rinne, J. (Dept. of Physics, Univ. of Helsinki (Finland)); Baeck, J. (Dept. of Forest Ecology, Univ. of Helsinki (Finland)); Hakola, H. (Finnish Meteorological Institute, Air Quality Research, Helsinki (Finland))

2009-07-01

n this paper, the research conducted on the emissions of the biogenic volatile organic compounds (BVOCs) from the European boreal zone, or taiga, is reviewed. We highlight the main findings and the key gaps in our knowledge. Ecosystem scale BVOC emissions from the Eurasian taiga are observed to be relatively low as compared with those from some forest ecosystems in warmer climates. One of the distinctive features of the Eurasian taiga is the predominance of monoterpene emitting coniferous trees. Recent research indicates that in addition to evaporation from storage structures, part of the monoterpene emission of conifers originates directly from synthesis. Monoterpene emission from boreal deciduous trees originates mainly directly from synthesis. The boreal trees exhibit distinct intra-species variation in the monoterpene mixtures they emit. Important sources of isoprene in the Eurasian taiga include Norway spruce, open wetland ecosystems and some non-dominant woody species, such as European aspen and willows. Many boreal tree species also emit non-terpenoid compounds and highly reactive sesquiterpenes. The future challenges in the research on BVOC emissions from the Eurasian taiga include (i) quantification and understanding the non-terpenoid VOC emissions from the taiga ecosystems, (ii) bringing ecosystems in the eastern Eurasian taiga into the sphere of BVOC emission studies, (iii) establishing long-term ecosystem flux studies combined with plant physiological measurements, and (iv) integrating knowledge and research skills on BVOC synthesis, storages and emissions, land cover changes and atmospheric processes in different spatial and temporal scales in order to better understand the impact of biosphere on atmospheric chemistry and composition in changing climate. (orig.)

Bird Perches Increase Forest Seeds on Puerto Rican Landslides.

Science.gov (United States)

Aaron B. Shiels; Lawrence R. Walker

2003-01-01

Landslides result in the loss of vertical vegetative structure, soil nutrients, and the soil seed bank. These losses impede timely recovery of tropical forest communities. In this study we added bird perches to six Puerto Rican landslides with three types of surfaces (bare, climbing fern, grass) in an effort to facilitate inputs of forest seeds through bird dispersal...

Utility of surface pollen assemblages to delimit Eastern Eurasian steppe types.

Directory of Open Access Journals (Sweden)

Feng Qin

Full Text Available Modern pollen records have been used to successfully distinguish between specific prairie types in North America. Whether the pollen records can be used to detect the occurrence of Eurasian steppe, or even to further delimit various steppe types was until now unclear. Here we characterized modern pollen assemblages of meadow steppe, typical steppe and desert steppe from eastern Eurasia along an ecological humidity gradient. The multivariate ordination of the pollen data indicated that Eurasian steppe types could be clearly differentiated. The different steppe types could be distinguished primarily by xerophilous elements in the pollen assemblages. Redundancy analysis indicated that the relative abundances of Ephedra, Tamarix, Nitraria and Zygophyllaceae were positively correlated with aridity. The relative abundances of Ephedra increased from meadow steppe to typical steppe and desert steppe. Tamarix and Zygophyllaceae were found in both typical steppe and desert steppe, but not in meadow steppe. Nitraria was only found in desert steppe. The relative abundances of xerophilous elements were greater in desert steppe than in typical steppe. These findings indicate that Eurasian steppe types can be differentiated based on recent pollen rain.

Haematology and Serum Biochemistry Parameters and Variations in the Eurasian Beaver (Castor fiber.

Directory of Open Access Journals (Sweden)

Simon J Girling

Full Text Available Haematology parameters (N = 24 and serum biochemistry parameters (N = 35 were determined for wild Eurasian beavers (Castor fiber, between 6 months - 12 years old. Of the population tested in this study, N = 18 Eurasian beavers were from Norway and N = 17 originating from Bavaria but now living extensively in a reserve in England. All blood samples were collected from beavers via the ventral tail vein. All beavers were chemically restrained using inhalant isoflurane in 100% oxygen prior to blood sampling. Results were determined for haematological and serum biochemical parameters for the species and were compared between the two different populations with differences in means estimated and significant differences being noted. Standard blood parameters for the Eurasian beaver were determined and their ranges characterised using percentiles. Whilst the majority of blood parameters between the two populations showed no significant variation, haemoglobin, packed cell volume, mean cell haemoglobin and white blood cell counts showed significantly greater values (p<0.01 in the Bavarian origin population than the Norwegian; neutrophil counts, alpha 2 globulins, cholesterol, sodium: potassium ratios and phosphorus levels showed significantly (p<0.05 greater values in Bavarian versus Norwegian; and potassium, bile acids, gamma globulins, urea, creatinine and total calcium values levels showed significantly (p<0.05 greater values in Norwegian versus Bavarian relict populations. No significant differences were noted between male and female beavers or between sexually immature (<3 years old and sexually mature (≥3 years old beavers in the animals sampled. With Eurasian beaver reintroduction encouraged by legislation throughout Europe, knowledge of baseline blood values for the species and any variations therein is essential when assessing their health and welfare and the success or failure of any reintroduction program. This is the first study to produce

Ancient Ethiopian genome reveals extensive Eurasian admixture in Eastern Africa

KAUST Repository

Gallego Llorente, M.

2015-10-09

Characterizing genetic diversity in Africa is a crucial step for most analyses reconstructing the evolutionary history of anatomically modern humans. However, historic migrations from Eurasia into Africa have affected many contemporary populations, confounding inferences. Here, we present a 12.5×coverage ancient genome of an Ethiopian male ("Mota") who lived approximately 4500 years ago. We use this genome to demonstrate that the Eurasian backflow into Africa came from a population closely related to Early Neolithic farmers, who had colonized Europe 4000 years earlier. The extent of this backflow was much greater than previously reported, reaching all the way to Central, West, and Southern Africa, affecting even populations such as Yoruba and Mbuti, previously thought to be relatively unadmixed, who harbor 6 to 7% Eurasian ancestry.

Ancient Ethiopian genome reveals extensive Eurasian admixture in Eastern Africa

KAUST Repository

Gallego Llorente, M.; Jones, E. R.; Eriksson, Anders; Siska, V.; Arthur, K. W.; Arthur, J. W.; Curtis, M. C.; Stock, J. T.; Coltorti, M.; Pieruccini, P.; Stretton, S.; Brock, F.; Higham, T.; Park, Y.; Hofreiter, M.; Bradley, D. G.; Bhak, J.; Pinhasi, R.; Manica, A.

2015-01-01

Characterizing genetic diversity in Africa is a crucial step for most analyses reconstructing the evolutionary history of anatomically modern humans. However, historic migrations from Eurasia into Africa have affected many contemporary populations, confounding inferences. Here, we present a 12.5×coverage ancient genome of an Ethiopian male ("Mota") who lived approximately 4500 years ago. We use this genome to demonstrate that the Eurasian backflow into Africa came from a population closely related to Early Neolithic farmers, who had colonized Europe 4000 years earlier. The extent of this backflow was much greater than previously reported, reaching all the way to Central, West, and Southern Africa, affecting even populations such as Yoruba and Mbuti, previously thought to be relatively unadmixed, who harbor 6 to 7% Eurasian ancestry.

Consequences of Hatch Phenology on Stages of Fish Recruitment.

Directory of Open Access Journals (Sweden)

David M Bogner

Full Text Available Little is known about how hatch phenology (e.g., the start, peak, and duration of hatching could influence subsequent recruitment of freshwater fishes into a population. We used two commonly sympatric fish species that exhibit different hatching phenologies to examine recruitment across multiple life stages. Nine yellow perch (Perca flavescens and bluegill (Lepomis macrochirus annual cohorts were sampled from 2004 through 2013 across larval, age-0, age-1, and age-2 life stages in a Nebraska (U.S.A. Sandhill lake. Yellow perch hatched earlier in the season and displayed a more truncated hatch duration compared to bluegill. The timing of hatch influenced recruitment dynamics for both species but important hatching metrics were not similar between species across life stages. A longer hatch duration resulted in greater larval yellow perch abundance but greater age-1 bluegill abundance. In contrast, bluegill larval and age-0 abundances were greater during years when hatching duration was shorter and commenced earlier, whereas age-0 yellow perch abundance was greater when hatching occurred earlier. As a result of hatch phenology, yellow perch recruitment variability was minimized sooner (age-0 life stage than bluegill (age-1 life stage. Collectively, hatch phenology influenced recruitment dynamics across multiple life stages but was unique for each species. Understanding the complexities of when progeny enter an environment and how this influences eventual recruitment into a population will be critical in the face of ongoing climate change.

Parental correlates of offspring sex ratio in Eurasian Oystercatchers

NARCIS (Netherlands)

Heg, D.; Dingemanse, NJ; Lessells, CM; Mateman, AC

2000-01-01

We investigated hatchling and fledgling sex ratios in Eurasian Oystercatchers (Haematopus ostralegus) using random amplified polymorphic DNA markers. The overall hatchling (53% males, n = 374 hatchlings from 177 broods) and fledgling (49% males, n = 51) sex ratio did not differ significantly from

Fish protein fingerprint in whole muscle samples of yellow perch ...

African Journals Online (AJOL)

Many studies have shown the impact of environmental and/or genetic factors on the growth and development of various fish species. However, the role of genes supporting the cellular and molecular mechanisms responsible for fish was to compare whole muscle proteomic profiles of large versus small growth yellow perch ...

Mortality factors and diseases in free-ranging Eurasian cranes (Grus grus) in Germany.

Science.gov (United States)

Fanke, Jane; Wibbelt, Gudrun; Krone, Oliver

2011-07-01

Detailed postmortem examinations were performed on 167 free-ranging Eurasian Cranes (Grus grus) from Germany, collected between September 1998 and December 2008 to evaluate causes of death and diseases. The most common causes of mortality were traumatic injuries (n=105, 62.9%) from collisions with power lines (n=39, 23.4%) and wire fences (n=12, 7.2%). A group of 28 Eurasian Cranes (16.8%) died from organophosphate intoxication. Predation by White-tailed Sea Eagles (Haliaeetus albicilla) and red foxes (Vulpes vulpes) occurred in four cases (2.4%). Pathologic changes due to infectious diseases were associated with Aspergillus spp. (n=7, 4.2%), endoparasites (n=7, 4.2%), avian poxvirus (n=6, 3.6%), Mycobacterium spp. (n=2, 1.2%), and adenovirus infection (n=1, 0.6%). A severe Strigea spp. infection (n=1, 0.6%) and a leiomyosarcoma (n=1, 0.6%) were newly recognized diseases in Eurasian Cranes in this study.

INVESTIGATIONS ON TECHNOLOGICAL PARAMETERS IN INTENSIVE REARING OF PIKE-PERCH (STIZOSTEDION LUCIOPERCA

Directory of Open Access Journals (Sweden)

Tamás Molnár

2000-06-01

Full Text Available Market demands and competition force the production of high quality freshwater fish in European aquaculture. In Hungary pike-perch is the most „noble” and perhaps the most sensitive fish species. One of the constraints of the increasing its production in natural waters, reservoirs and ponds is the shortage in adequate sized alevins. The possible solution of this problem can be the elaboration of intensive rearing technics of pond prereared fry. The aims of the present work were to test the growing capacity, feed conversion and survival of pike-perch in intensive circumstances. Fish were kept in 130 l aquaria working in recirculation system at an average water temperature of 220.5 C. Two stocking densities were applied (18 and 36 fish/aquarium. Minced fish (test and live prey (control were offered twice a day till satiation in two replications. The experiment lasted 4 weeks. According to our results minced fish is suitable feed in the intensive rearing of pike-perch alevins. Daily food intake was only influenced significantly by different feeds (2.01g vs.4.53 g, test and control, respectively. Feeding and stocking density had significant effect (P=0.001 and 0.017 on the average weight gain (0.52 g and 1.40 g for minced fish and live feed, respectively, 1.02 g in lower and 0.90 g in higher density. Owning to the high variances treatment effect on feed conversion proved to be not significant. Average survival of the minced fish fed group was 62.2 % vs. 78.8 % of the live fish fed alevins. This difference was significant (P<0.01 in the first two weeks when almost all of the losses happened due to cannibalism and other unknown reasons. Based on our results a period of 10–14 days is needed for pre-reared pike-perch to change gradually their feeding from zooplankton to minced fish diet.

Pan-Eurasian Experiment (PEEX: towards a holistic understanding of the feedbacks and interactions in the land–atmosphere–ocean–society continuum in the northern Eurasian region

Directory of Open Access Journals (Sweden)

H. K. Lappalainen

2016-11-01

Full Text Available The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic–boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX, a multi-scale, multi-disciplinary and international program started in 2012 (https://www.atm.helsinki.fi/peex/. PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land–atmosphere–aquatic–society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context.

36Cl in shallow, perched aquifers from central Indiana

Science.gov (United States)

Vogt, S.; Elmore, D.; Fritz, S. J.

1994-06-01

36Cl/Cl ratios and chloride concentrations were measured in several shallow, perched aquifers situated within glacial till in west-central Indiana (USA). Most of these aquifers show 36Cl/Cl ratios which have to be attributed to admixed 36Cl from nuclear weapons tests in the 1950s and 1960s. Two wells from Purdue's Horticultural Farm tap perched aquifers uninfluenced by anthropogenic sources of chloride, and their 36Cl/Cl ratios are comparable with ratios measured in modern, local precipitation. As such, the chloride contents of these wells (1 to 3 ppm) reflect evaporative concentration of the precipitation's chloride contents (averaging 0.17 ppm) in the vadose zone. Since one of these two wells (HA-2a) does not contain any detectable tritium, we conclude that recent pre-bomb 36Cl/Cl ratios and 36Cl deposition in precipitation are quite similar to those in modern precipitation. We attribute the slight 36Cl excess of about 20% in both of these wells largely to 36Cl deposition associated with dry fall-out. As much as 2 × 10 4 at. 36Cl/cm 2 might reach the surface via dry fall-out annually.

Seismic Tomography of the Arabian-Eurasian Collision Zone and Surrounding Areas

National Research Council Canada - National Science Library

Toksoz, M. N; Van der Hilst, Robert D; Sun, Youshun; Gulen, Levent; Kalafat, Dogan; Kuleli, Huseyin S; Li, Chang; Zhang, Haijiang

2008-01-01

... and surrounding areas, including Iran, Arabia, Eastern Turkey, and the Caucasus. The Arabian-Eurasian plate boundary is a complex tectonic zone shaped by continent-continent collision processes...

Hydrological connectivity of perched aquifers and regional aquifers in semi-arid environments: a case study from Namibia

Science.gov (United States)

Hamutoko, J. T.; Wanke, H.

2017-12-01

Integrated isotopic and hydrological tracers along with standard hydrological data are used to understand complex dry land hydrological processes on different spatial and temporal scales. The objective of this study is to analyse the relationship between the perched aquifers and the regional aquifer using hydrochemical data and isotopic composition in the Cuvelai-Etosha Basin in Namibia. This relation between the aquifers will aid in understanding groundwater recharge processes and flow dynamics. Perched aquifers are discontinuous shallow aquifers with water level ranging from 0 to 30 meters below ground level. The regional aquifer occurs in semi-consolidated sandstone at depths between about 60 and 160 meters below ground level. Water samples were collected from both aquifers in 10 villages and were analysed for major ions and stable isotopes. The results show overlapping hydrochemistry and isotopic compositions of both aquifers in 8 villages which suggest the possibility of perched aquifer water infiltrating into the regional aquifer. In two villages the hydrochemistry and isotopic composition of the aquifers are totally different and this suggests that there is no interaction between this aquifers. Areas where perched aquifers are connected to regional aquifers maybe recharge zones. These finding have important implications for groundwater resource management.

Eurasian Economic Union: Opportunities and Barriers to Regional and Global Leadership

Directory of Open Access Journals (Sweden)

In Andronova

2016-09-01

Full Text Available The Eurasian Economic Union (EEU is a new integration grouping in the post-Soviet space that is generating heightened interest as a global economy with the potential to become a new regional and global actor. This article analyzes the effectiveness of the Eurasian integration processes and proposes several actions to strengthen economic relations among EEU members through detecting and building common economic interests. Russia accounts for as much as 87% of the EEU’s geo-economic potential, which stresses the country’s role as anintegrative hub. The EEU benefits are thus unevenly distributed among its participants. Moreover, these benefits lack consistency and long-term orientation, which may threaten the EEU’s existence if markets and international economic relations change.This article analyses the interrelation and interdependency of national economies in terms of the mutual trade in goods and services and investment cooperation. It finds that the level of economic integration does not meet the interests of strengthening Eurasian integration. Despite the huge benefits of the Customs Union, trade volumes have not increased and the structure of manufacturing and cooperation ties remain unchanged. This article recommends that developing and implementing a common industrial and agricultural policy would strengthen the EEU, and proposes an approach to estimate the results of such a policy.

COMPARISON OF AGE ESTIMATES FROM VARIOUS HARD PARTS FOR REDFIN PERCH, Percafluviatilis, IN TASMANIA

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Irwan Jatmiko

2013-06-01

Full Text Available Whole otoliths, sectioned otoliths, scales and vertebrae were used to select the most suitable for age determination of redfin perch, Percafluviatilis. Redfin perch were sampled from Trevallyn Lake and Brushy Lagoon using fyke nets, gillnets, electrofishing and rod and line angling. Age estimates were assessed for comparison between readings and among structures. One-wayANOVA of readability scores highlighted that sectioned otolith was the most obvious compare to other hard parts. Sectioned otoliths also showed the highest (93.9% agreement between readings, followed by vertebrae (68.7, scales (38.8 and whole otoliths (29.9. Furthermore, there were no significantly different (p>0.05 between first and second readings from sectioned otolith and vertebrae but significantly different (p <0.05 to those from scales and whole otoliths. When sectioned otoliths’ ages were compared with other structures, vertebrae showed the highest (47.6% agreement to those followed by scales (25.2% and whole otoliths (20.4%. Age estimates from sectioned otoliths were significantly different (p<0.05 to the values obtained from vertebrae, scales and whole otoliths.This finding demonstrated that sectioned otoliths are the best hard part for age determination for redfin perch in Tasmania.

Radiographic evaluation of perching-joint angles in cockatiels (Nymphicus hollandicus), Hispaniolan Amazon parrots (Amazona ventralis), and barred owls (Strix varia).

Science.gov (United States)

Bonin, Glen; Lauer, Susanne K; Guzman, David Sanchez-Migallon; Nevarez, Javier; Tully, Thomas N; Hosgood, Giselle; Gaschen, Lorrie

2009-06-01

Information on perching-joint angles in birds is limited. Joint immobilization in a physiologic perching angle has the potential to result more often in complete restoration of limb function. We evaluated perching-joint angles in 10 healthy cockatiels (Nymphicus hollandicus), 10 Hispaniolan Amazons (Amazona ventralis), and 9 barred owls (Strix varia) and determined intra- and interobserver variability for goniometric measurements in 2 different radiographic projections. Intra- and interobserver variation was less than 7% for all stifle and intertarsal joint measurements but frequently exceeded 10% for the hip-joint measurements. Hip, stifle, and intertarsal perching angles differed significantly among cockatiels, Hispaniolan Amazon parrots, and barred owls. The accuracy of measurements performed on straight lateral radiographic projections with superimposed limbs was not consistently superior to measurements on oblique projections with a slightly rotated pelvis. Stifle and intertarsal joint angles can be measured on radiographs by different observers with acceptable variability, but intra- and interobserver variability for hip-joint-angle measurements is higher.

Pan Eurasian EXperiment (PEEX) - towards a new multinational environment and climate research effort in Eurasia

Science.gov (United States)

Petäjä, Tuukka; Kulmala, Markku; Lappalainen, Hanna; Sipilä, Mikko; Sorvari, Sanna; Alekseychik, Pavel; Paramonov, Mikhail; Kerminen, Veli-Matti; Zilitinkevich, Sergej

2013-04-01

Boreal forests are a substantial source of greenhouse gases, biogenic volatile organic compounds (BVOCs) and natural aerosols, the critical atmospheric components related to climate change processes. A large fraction of boreal forests of the world is situated in Siberian region. Representative measurements of carbon dioxide (CO2) and methane (CH4) concentrations, BVOC emissions and aerosols production from Siberian are of special importance when estimating global budgets of climate change relevant factors. The scope of a new concept of the Pan Eurasian Experiment (PEEX) is to set up a process for planning of a large-scale, long-term, coordinated observations and modeling experiment in the Pan Eurasian region, especially to cover ground base, airborne and satellite observations together with global and regional models to find out different forcing and feedback mechanisms in the changing climate. University of Helsinki together with Finnish Meteorological institute are organizing the Pan-Eurasian Experiment and to gather all the European and Russian key players in the field of climate and Earth system science to plan the future research activities in the Pan-Eurasian region. In the European scale PEEX is part of the JPI Climate Fast Track Activity 1.3. "Changing cryosphere in the climate system - from observations to climate modeling". PEEX research topics are closely related the NordForsk's Top Research Initiative CRAICC - Cryosphere - atmosphere interaction in the changing Arctic climate. PEEX is also a central part of the ongoing the Finnish Cultural Foundation - Earth System modeling Working Group activity (2012-2013). PEEX scientific aims and future actions to develop Pan Eurasian research infrastructure can be linked to several EC and ESA funded activities aiming to develop next generation research infrastructures and data products: EU-FP7-ACTRIS-I3-project (Aerosols, Clouds, and Trace gases Research InfraStructure Network-project 2011-2015); ICOS a research

An update of the distribution of selected radiochemical and chemical constituents in perched ground water, Idaho National Laboratory, Idaho, Emphasis 1999-2001

Science.gov (United States)

Davis, Linda C.

2006-01-01

Radiochemical and chemical wastes generated at facilities at the Idaho National Laboratory (INL) were discharged since 1952 to infiltration ponds at the Reactor Technology Complex (RTC) (known as the Test Reactor Area [TRA] until 2005), and the Idaho Nuclear Technology and Engineering Center (INTEC) and buried at the Radioactive Waste Management Complex (RWMC). Disposal of wastewater to infiltration ponds and infiltration of surface water at waste burial sites resulted in formation of perched ground water in basalts and in sedimentary interbeds above the Snake River Plain aquifer. Perched ground water is an integral part of the pathway for waste-constituent migration to the aquifer. The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, maintains ground-water monitoring networks at the INL to determine hydrologic trends, and to monitor the movement of radiochemical and chemical constituents in wastewater discharged from facilities to both perched ground water and the aquifer. This report presents an analysis of water-quality and water-level data collected from wells completed in perched ground water at the INL during 1999-2001, and summarizes historical disposal data and water-level-and water-quality trends. At the RTC, tritium, strontium-90, cesium-137, dissolved chromium, chloride, sodium, and sulfate were monitored in shallow and deep perched ground water. In shallow perched ground water, no tritium was detected above the reporting level. In deep perched ground water, tritium concentrations generally decreased or varied randomly during 1999-2001. During October 2001, tritium concentrations ranged from less than the reporting level to 39.4?1.4 picocuries per milliliter (pCi/mL). Reportable concentrations of tritium during July-October 2001 were smaller than the reported concentrations measured during July-December 1998. Tritium concentrations in water from wells at the RTC were likely affected by: well's distance from the

Reconstructions of human history by mapping dental markers in living Eurasian populations

Science.gov (United States)

Kashibadze, Vera F.; Nasonova, Olga G.; Nasonov, Dmitry S.

2013-01-01

Using advances in gene geography and anthropophenetics, the phenogeographical method for anthropological research was initiated and developed using dental data. Statistical and cartographical analyses are provided for 498 living Eurasian populations. Mapping principal components supplied evidence for the phene pool structure in Eurasian populations, and for reconstructions of Homo sapiens history on the continent. Longitudinal variability seems to be the most important regularity revealed by principal components analysis (PCA) and mapping, indicating the division of the whole area into western and eastern main provinces. So, the most ancient scenario in the history of Eurasian populations developed from two perspective different groups: a western group related to ancient populations of West Asia and an eastern one rooted in ancestry in South and/or East Asia. In spite of the enormous territory and the revealed divergence, the populations of the continent have undergone wide scale and intensive timeespace interaction. Many details in the revealed landscapes are background to different historical events. Migrations and assimilation are two essential phenomena in Eurasian history: the widespread of the western combination through the whole continent to the Pacific coastline and the movement of the paradoxical combinations of eastern and western markers from South or Central Asia to the east and west. Taking into account that no additional eastern combinations in the total variation in Asian groups have been found, but that mixed or western markers' sets and that eastern dental characteristics are traced in Asia since Homo erectus, the assumption is made in favour of the hetero-level assimilation in the eastern province and of net-like evolution of H. sapiens.

Yellow perch embryo-larval survival and growth in surface waters associated with oil-sands mining

International Nuclear Information System (INIS)

Peters, L.E.; Heuvel, M.R. van den; Dixon, D.G.; Power, M.; Boerger, H.; MacKinnon, M.D.; Meer, T. Van

1995-01-01

As part of their land reclamation strategy, Syncrude Canada Ltd. is currently developing environmentally acceptable tailings disposal methods. Fine tailings, a suspension of clay and residual bitumen, is the waste product from oil sands extraction. Fine-tailings contain naphthenic acids, a group of saturated aliphatic and alicyclic carboxylic acids, which occur naturally in petroleum and are partly responsible for the toxicity of process water. The wet landscape method involves covering fine tails with a layer of water such that a self-sustaining ecosystem can be established. A 5 ha demonstration pond with a bottom of fine-tailings was constructed and stocked with yellow perch for experimental purposes. Two other reclaimed ponds formed with oil-sands overburden material were also stocked with perch. Adult perch sampled in the fall of 1995 from the experimental and reclaimed ponds exhibited a 2-fold induction of MFO activity compared to the source lake; indicating organic compound exposure. Perch from one of the reclaimed ponds showed significantly reduced circulating reproductive hormone levels, gonad size and smaller ovarian follicles. Reproductive parameters were not different between the source lake and the remaining ponds. Paired lab and field experiments were conducted to determine if contaminants present would be detrimental to egg viability and development of larvae either through direct exposure of spawned eggs or indirectly by effecting oogenesis. An early life stage toxicity test was also performed using commercially available naphthenic acid standard. Endpoints measured were percent fertilization, percent hatch, mortality, deformities, timing of developmental periods and larval growth

Nile perch fish processing waste along Lake Victoria in East Africa ...

African Journals Online (AJOL)

Nile perch fish processing waste along Lake Victoria in East Africa: Auditing and characterization. ... African Journal of Environmental Science and Technology ... If you would like more information about how to print, save, and work with PDFs, Highwire Press provides a helpful Frequently Asked Questions about PDFs.

Nile perch fish processing waste along Lake Victoria in East Africa ...

African Journals Online (AJOL)

In East Africa, Nile perch fish processing into chilled fish fillet for export along Lake Victoria generate large proportions of both solid and liquid wastes. However, no thorough auditing and characterization of the waste has been done that would guide potential value addition through bioconversions and waste management.

Fatty acid composition of muscle and heart tissue of Nile perch ...

African Journals Online (AJOL)

The fatty acid composition in the heart tissue and muscle tissue of the Nile perch, Lates niloticus, and Nile tilapia, Oreochromis niloticus populations from Lakes Kioga and Victoria was determined by methanolysis and gas chromatography of the resulting fatty acid methyl esters. The analytical data were treated by ...

Sex-dependent responses of perch to changes in water clarity and temperature

Czech Academy of Sciences Publication Activity Database

Estlander, Satu; Nurminen, L.; Mrkvička, Tomáš; Olin, M.; Rask, M.; Lehtonen, H.

2015-01-01

Roč. 24, č. 4 (2015), s. 544-552 ISSN 0906-6691 Institutional support: RVO:60077344 Keywords : increasing water colour * climate change * European perch * feeding efficiency * sexual size dimorphism Subject RIV: EH - Ecology, Behaviour Impact factor: 2.052, year: 2015

Eutrophication, Nile perch and food-web interactions in south-east Lake Victoria

NARCIS (Netherlands)

Cornelissen, I.J.M.

2015-01-01

The increasing eutrophication, the introduction of Nile perch (Lates niloticus) and the increasing fishing pressure has changed Lake Victoria tremendously the last century. Since the 1960s, eutrophication increased primary production, enabling an increase in fish production. However,

Interspecies differences in the accumulation of tributyltin and its metabolites under dietary exposure in sea perch, Lateolabrax japonicus, and red sea bream, Pagrus major.

Science.gov (United States)

Uno, Seiichi; Murakami, Masayo; Kokushi, Emiko; Koyama, Jiro

2011-02-01

Interspecies differences in the accumulation of dietary tributyltin (TBT) between sea perch, Lateolabrax japonicus, and red sea bream, Pagrus major, were studied. Although TBTs in both species reached steady-state condition in low-concentration group (L-group, 200 ng/g nominal concentration) by 1 week, it increased up to the end of exposure in high-concentration group (H-group, 3000 ng/g nominal concentration). In H-group, the accumulation rate of TBT in sea perch from 1 to 2 weeks was much higher than in red sea bream, which were 2.4-fold for sea perch and 1.7-fold for red sea bream, although TBT concentrations were similar between sea perch and red sea bream in L-group. Furthermore, in the H-group, the concentrations of TBT at 1 and 2 weeks were about 1.3- and 1.9-fold, respectively, higher in the sea perch than in the red sea bream. On the other hand, DBT residue in red sea bream was about 1.4-fold higher in sea perch for the L-group but concentrations were similar in both fishes for the H-group. These results suggest that red sea bream could metabolize faster the TBT to DBT than sea perch. This study also reveals that fish probably could absorb TBT through the food chain. The uptake of TBT by fish should be regarded in the real environment, because TBT concentration in seawater has been decreasing and now already at significantly low level. Copyright © 2009 Wiley Periodicals, Inc.

Little Galloo Island, Lake Ontario: A review of nine years of double-crested cormorant diet and fish consumption information

Science.gov (United States)

Johnson, James H.; Ross, Robert M.; McCullough, Russ D.

2002-01-01

The diet of double-crested cormorants (Phalacrocorax auritus) on Little Galloo Island (LGI) in the eastern basin of Lake Ontario has been quantified since 1992. Over the past nine years considerable information has been generated on cormorant feeding ecology through the examination of approximately 12,000 pellets collected on LGI, where three distinct cormorant feeding periods, pre-chick, chick, and post-chick, are delineated by differences in diet composition and daily fish consumption. Yellow perch (Perca flavescens) were the major prey during pre-chick and post-chick feeding periods. Alewife (Alosa pseudoharengus), which move inshore to spawn in mid-June, dominated (>60%) cormorant diets during the chick feeding period. Mean daily fish consumption (14.6) during the pre-chick feeding period was significantly greater than during the chick feeding (9.3) or post-chick feeding (8.0) periods. The proportion of smallmouth bass (Micropterus dolomieu) in the diet increased over the season (0.8% to 7.2%), while the size of bass consumed declined (214 mm to 143 mm). Forage fish (mainly alewife, three-spine sticklebacks [Gasterosteus aculeatus] and minnows) comprised 58% of the diet of LGI cormorants, followed by panfish (37%) (yellow perch, pumpkinseed [Lepomis gibbosus], rock bass [Ambloplites rupestris]) and gamefish (5%) (mostly smallmouth bass). On the average LGI cormorants consumed about 32.8 million fish annually, weighing about 1.4 million kilograms. Cormorants from LGI consumed more biomass of smallmouth bass and yellow perch annually than is taken by sport (bass and yellow perch) and commercial (perch) fishermen.

Of paleo-genes and Perch: what if an "alien" is actually a native?

Science.gov (United States)

Stager, J Curt; Sporn, Lee Ann; Johnson, Melanie; Regalado, Sean

2015-01-01

Documenting whether a biotic taxon is native or alien to an ecosystem has theoretical value for ecological and evolutionary studies, and has practical value because it can potentially identify a taxon as a desirable component of an ecosystem or target it for removal. In some cases, however, such background information is inadequate or unavailable. Here we use paleo-DNA to re-evaluate the historical status of yellow perch in the 6 million acre Adirondack State Park of northern New York. Yellow perch DNA in a 2200-year sediment record reveals a long-term native status for these supposedly alien fish and challenges assumptions that they necessarily exclude native trout from upland lakes. Similar approaches could be applied to other species with uncertain historical distributions and could help to identify unrecognized pockets of biodiversity.

Yellow perch (Perca flavescens) mercury unaffected by wildland fires in northern Minnesota

Science.gov (United States)

Charlotte E. Riggs; Randall K. Kolka; Edward A. Nater; Emma L. Witt; Trent R. Wickman; Laurel G. Woodruff; Jason T. Butcher

2017-01-01

Wildland fire can alter mercury (Hg) cycling on land and in adjacent aquatic environments. In addition to enhancing local atmospheric Hg redeposition, fire can influence terrestrial movement of Hg and other elements into lakes via runoff from burned upland soil. However, the impact of fire on water quality and the accumulation of Hg in fish remain equivocal. We...

Monitoring and assessment of conservation status of the Eurasian Otter (Lutra lutra) in Denmark

DEFF Research Database (Denmark)

Søgaard, Bjarne; Madsen, Aksel Bo; Elmeros, Morten

Monitoring and assessment of conservation status of the Eurasian Otter Lutra lutra in Denmark Søgaard B. ¹, Madsen A.B.¹, Elmeros M.¹ ¹Institute of Bioscience - Kaloe, Aarhus University. Keywords: Eurasian Otter; Monitoring; Conservation status According to the EU Habitats Directive Denmark has...... of the otter inside Denmark, DNA analysis of dead found otters in Schleswig-Holstein (North Germany) shows that “Danish” otter have crossed the border to Germany connecting the Danish population to the East German population, which spreads into Schleswig-Holstein from Mecklenburg-Vorpommern....

Biology, History, Status and Conservation of Sacramento Perch, Archoplites interruptus

Directory of Open Access Journals (Sweden)

Patrick K Crain

2011-04-01

Full Text Available This paper is a review of the biology of Sacramento perch (Archoplites interruptus based mainly on recent studies of their distribution, ecology, physiology, and genetics. The Sacramento perch is the only member of the family Centrarchidae that is endemic to California. It is most closely related to the rock basses (Ambloplites spp. and is thought to have split from its eastern cousins during the Middle Miocene Period (15.5 to 5.2 million years ago, MYA. Their native range includes the Central Valley, Pajaro and Salinas rivers, tributaries to the San Francisco Estuary (e.g., Alameda Creek, and Clear Lake (Lake County. Today, they are most likely extirpated from all of their native range. They are known to persist in 28 waters outside their native range: 17 in California, nine in Nevada, and one each in Utah and Colorado. Disappearance from their native range coincided with massive changes to aquatic habitats in the Central Valley and with the introduction of alien species, including other centrarchids. Unfortunately, many populations established outside their native range have also disappeared and are continuing to do so.

Eurasian golden jackal as host of canine vector-borne protists

Czech Academy of Sciences Publication Activity Database

Mitková, B.; Hrazdilová, K.; D'Amico, G.; Duscher, G. G.; Suchentrunk, F.; Forejtek, P.; Gherman, C.M.; Matei, I.A.; Ionică, A.M.; Daskalaki, A.A.; Mihalca, A. D.; Votýpka, Jan; Hulva, P.; Modrý, David

2017-01-01

Roč. 10, APR 14 (2017), č. článku 183. ISSN 1756-3305 Institutional support: RVO:60077344 Keywords : Eurasian golden jackal * Babesia * Hepatozoon * Theileria annae * Leishmania Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine OBOR OECD: Veterinary science Impact factor: 3.080, year: 2016

Of paleo-genes and Perch: what if an "alien" is actually a native?

Directory of Open Access Journals (Sweden)

J Curt Stager

Full Text Available Documenting whether a biotic taxon is native or alien to an ecosystem has theoretical value for ecological and evolutionary studies, and has practical value because it can potentially identify a taxon as a desirable component of an ecosystem or target it for removal. In some cases, however, such background information is inadequate or unavailable. Here we use paleo-DNA to re-evaluate the historical status of yellow perch in the 6 million acre Adirondack State Park of northern New York. Yellow perch DNA in a 2200-year sediment record reveals a long-term native status for these supposedly alien fish and challenges assumptions that they necessarily exclude native trout from upland lakes. Similar approaches could be applied to other species with uncertain historical distributions and could help to identify unrecognized pockets of biodiversity.

Badger hair in shaving brushes comes from protected Eurasian badgers

NARCIS (Netherlands)

Domingo-Roura, X.; Marmi, J.; Ferrando, A.; López-Giráldez, F.; Macdonald, D.W.; Jansman, H.A.H.

2006-01-01

The Eurasian badger (Meles meles) is included in Appendix III of the Bern Convention and protected by national laws in many European countries. Badger hair is used to manufacture luxury shaving brushes, although it is frequently argued that the hog badger (Arctonyx collaris), which in Europe is an

Perches and elevated platforms in commercial broiler farms: use and effect on walking ability, incidence of tibial dyschondroplasia and bone mineral content.

Science.gov (United States)

Kaukonen, E; Norring, M; Valros, A

2017-05-01

Modern fast-growing broilers spend excessive periods resting and their activity further decreases with age. Inactivity has been suggested to increase impaired gait and the incidence of leg disorders. Tibial dyschondroplasia (TD) is a common leg pathology in broilers. A more complex environment might facilitate more activity and improve leg health. Perches or elevated platforms bring variety to broilers' environment and could motivate more locomotion. This study examined the impact of perches and elevated platforms on walking ability, the occurrence of TD and level of bone ash and mineral contents. The investigation was performed on four commercial broiler farms throughout six consecutive batches with platforms and four to five with perches. On each farm at least two separate houses were included, enabling the comparison of furnished flocks to control flocks during each batch. Plastic slats with ramp access elevated by 30 cm or wooden perches of 10 and 30 cm height were offered in the furnished house. Farmers recorded the platform and perch usage twice a week with a five-point scale. Gait was scored before slaughter on a six-point scale according to the Welfare Quality® assessment protocol for poultry. The severity of TD was determined using a four-point scale on farm from all birds gait scored as 3 and at slaughter from 200 birds/flock. Farmers estimated 50% to 100% of the platforms to be occupied in all flocks throughout the entire growing period. Only single birds were perching, thus perch structures were constantly evaluated to be empty. Due to the low use, the perch-equipped houses were excluded when analysing bone content, walking ability and TD. On average, 30% of the tested birds exhibited gait score ⩾3. Younger scoring age resulted in a lower mean gait score and a lower percentage of scores 3 and 4 to 5. Overall, 2.3% of the birds examined at slaughter and 3.5% of the birds with gait score 3 were affected by TD. Leg health was better in birds with access

Mechanisms of Egg Yolk Formation and Implications on Early Life History of White Perch (Morone americana.

Directory of Open Access Journals (Sweden)

Justin Schilling

Full Text Available The three white perch (Morone americana vitellogenins (VtgAa, VtgAb, VtgC were quantified accurately and precisely in the liver, plasma, and ovary during pre-, early-, mid-, and post-vitellogenic oocyte growth using protein cleavage-isotope dilution mass spectrometry (PC-IDMS. Western blotting generally mirrored the PC-IDMS results. By PC-IDMS, VtgC was quantifiable in pre-vitellogenic ovary tissues and VtgAb was quantifiable in pre-vitellogenic liver tissues however, neither protein was detected by western blotting in these respective tissues at this time point. Immunohistochemistry indicated that VtgC was present within pre-vitellogenic oocytes and localized to lipid droplets within vitellogenic oocytes. Affinity purification coupled to tandem mass spectrometry using highly purified VtgC as a bait protein revealed a single specific interacting protein (Y-box binding protein 2a-like [Ybx2a-like] that eluted with suramin buffer and confirmed that VtgC does not bind the ovary vitellogenin receptors (LR8 and Lrp13. Western blotting for LR8 and Lrp13 showed that both receptors were expressed during vitellogenesis with LR8 and Lrp13 expression highest in early- and mid-vitellogenesis, respectively. The VtgAa within the ovary peaked during post-vitellogenesis, while VtgAb peaked during early-vitellogenesis in both white perch and the closely related striped bass (M. saxatilis. The VtgC was steadily accumulated by oocytes beginning during pre-vitellogenesis and continued until post-vitellogenesis and its composition varies widely between striped bass and white perch. In striped bass, the VtgC accounted for 26% of the vitellogenin-derived egg yolk, however in the white perch it comprised only 4%. Striped bass larvae have an extended developmental window and these larvae have yolk stores that may enable them to survive in the absence of food for twice as long as white perch after hatch. Thus, the VtgC may play an integral role in providing nutrients to

Eurasian Economic Union: A Regional Economic Hegemony Initiative

OpenAIRE

Serdar YILMAZ

2017-01-01

It can be assumed that international relations terminology has not mentioned enough about the significance of the Eurasian Economic Union in territorial as well as in economic terms during a period of growing geopolitical risks and high interdependence between the member countries and the rest. According to Kazakhstan’s President Nursultan Nazarbayev, it is truly difficult for states to overcome economic, political and security issues and therefore, states need to act together against the pro...

Distribution and accumulation of rotenone in tissues of warm water fishes

International Nuclear Information System (INIS)

Rach, J.J.; Gingerich, W.H.

1986-01-01

The tissue distribution of rotenoid residues was determined in tissues of common carp Cyprinus carpio (88.2 g), bluegills Lepomis macrochirus (47.9 g), and yellow perch Perca flavescens (67.7 g) after the fish were exposed to 50μg/L of rotenone-6a 14 C(15.9 x 10 4 Bq/μM). Exposures were terminated 1 h after the fish were moribund and failed to respond to gentle prodding. The fish were dissected, and various tissues were oxidized to determine 14 C-rotenone accumulation and distribution. Major rotenone metabolites were identified by gradient-elution high performance liquid chromatography. The exposure time required for fish to reach total incapacitation was 3 h for bluegills and yellow perch, and 11.25 h for common carp. The mean rotenoid concentrations (μg/100g fish) in the whole body were 22.4 in yellow perch, 39.7 in bluegills, and 107.8 in common carp. The percentage of rotenone-derived 14 C activity was higher in the carcass components than in the head or viscera; the skin and bone contained about 60% of the carcass activity. The highest relative rotenoid concentrations were found in the liver, bile, gills, brain, and heart. Percentages of total rotenoid material as parent rotenone were highest in yellow perch (70.0 in the viscera and 84.4 in the fillet), followed by those for bluegills (22.7 and 27.8) and common carp (9.7 and 48.5)

Development of an enzyme-linked immunosorbent assay for detection of chicken osteocalcin and its use in evaluation of perch effects on bone remodeling in caged White Leghorns.

Science.gov (United States)

Jiang, S; Cheng, H W; Hester, P Y; Hou, J-F

2013-08-01

Osteocalcin (OC) is a sensitive biochemical marker for evaluating bone turnover in mammals. The role of avian OC is less clear because of the need for a chicken assay. Our objectives were to develop an assay using indirect competitive ELISA for detecting chicken serum OC and use the assay to examine the effects of perches on bone remodeling in caged hens. Anti-chicken OC polyclonal antibody was produced by immunization of rabbits with a recombinant OC from Escherichia coli. Chicken OC extracted from bone was used as a coated protein, and purified chicken OC was used for calibration. The limit of detection of the developed OC ELISA was 0.13 ng/mL. The intra- and interassay CV were housed in conventional cages with or without perches. Serum samples were collected from 71-wk-old White Leghorn hens subjected to 4 treatments. Treatment 1 was control chickens that never had access to perches during their life cycle. Treatment 2 chickens had perches during the pullet phase (0 to 16.9 wk of age), whereas treatment 3 chickens had perches only during the egg-laying phase of the life cycle (17 to 71 wk of age). Treatment 4 chickens always had access to perches (0 to 71 wk of age). Correlation between the 2 assays was 0.62 (P < 0.0001). Levels of serum OC using the developed chicken ELISA were higher than that detected using the Rat-Mid ELISA (P < 0.0001). Results from the chicken ELISA assay showed that hens with perch access had higher concentrations of serum OC than hens without perches during egg laying (P = 0.04). Pullet access to perches did not affect serum OC levels in 71-wk-old hens (P = 0.15). In conclusion, a chicken OC ELISA has been validated that is sensitive and accurate with adequate discriminatory power for measuring bone remodeling in chickens.

Mercury in freshwater fish of northeast North America--a geographic perspective based on fish tissue monitoring databases.

Science.gov (United States)

Kamman, Neil C; Burgess, Neil M; Driscoll, Charles T; Simonin, Howard A; Goodale, Wing; Linehan, Janice; Estabrook, Robert; Hutcheson, Michael; Major, Andrew; Scheuhammer, Anton M; Scruton, David A

2005-03-01

As part of an initiative to assemble and synthesize mercury (Hg) data from environmental matrices across northeastern North America, we analyzed a large dataset comprised of 15,305 records of fish tissue Hg data from 24 studies from New York State to Newfoundland. These data were summarized to provide mean Hg concentrations for 40 fish species and associated families. Detailed analyses were carried out using data for 13 species. Hg in fishes varied by geographic area, waterbody type, and waterbody. The four species with the highest mean Hg concentrations were muskellunge (Esox masquinongy), walleye (Sander vitreus), white perch (Morone americana), and northern pike (Esox luscius). Several species displayed elevated Hg concentrations in reservoirs, relative to lakes and rivers. Normalized deviations from mean tissue levels for yellow perch (Perca flavescens) and brook trout (Salvelinus fontinalis) were mapped, illustrating how Hg concentrations in these species varied across northeastern North America. Certain geographic regions showed generally below or above-average Hg concentrations in fish, while significant heterogeneity was evident across the landscape. The proportion of waterbodies exhibiting exceedances of USEPA's criterion for fish methylmercury ranged from 14% for standard-length brook trout fillets to 42% for standard-length yellow perch fillets. A preliminary correlation analysis showed that fish Hg concentrations were related to waterbody acidity and watershed size.

A Transient Numerical Simulation of Perched Ground-Water Flow at the Test Reactor Area, Idaho National Engineering and Environmental Laboratory, Idaho, 1952-94

International Nuclear Information System (INIS)

Orr, B. R.

1999-01-01

Studies of flow through the unsaturated zone and perched ground-water zones above the Snake River Plain aquifer are part of the overall assessment of ground-water flow and determination of the fate and transport of contaminants in the subsurface at the Idaho National Engineering and Environmental Laboratory (INEEL). These studies include definition of the hydrologic controls on the formation of perched ground-water zones and description of the transport and fate of wastewater constituents as they moved through the unsaturated zone. The definition of hydrologic controls requires stratigraphic correlation of basalt flows and sedimentary interbeds within the saturated zone, analysis of hydraulic properties of unsaturated-zone rocks, numerical modeling of the formation of perched ground-water zones, and batch and column experiments to determine rock-water geochemical processes. This report describes the development of a transient numerical simulation that was used to evaluate a conceptual model of flow through perched ground-water zones beneath wastewater infiltration ponds at the Test Reactor Area (TRA)

Disseminated visceral coccidiosis in Eurasian cranes (Grus grus) in the UK.

Science.gov (United States)

O'Brien, M F; Brown, M J; Stidworthy, M F; Peirce, M A; Marshall, R N; Honma, H; Nakai, Y

2011-02-26

Clinical disease and mortalities due to disseminated visceral coccidiosis were identified for the first time in a group of captive juvenile Eurasian cranes (Grus grus) in the UK during 2008. Presumptive diagnosis was made from the finding of granulomatous nodules in the liver, spleen and other organs at gross postmortem examination, and confirmed histologically by the presence of intracellular coccidial stages within lesions. The species of coccidian was determined to be Eimeria reichenowi on the basis of faecal oocyst morphology and sequencing of 18S rDNA by PCR. A further outbreak of clinical disease occurred in the same enclosure in 2009, affecting a new group of juvenile Eurasian cranes and demoiselle cranes (Anthropoides virgo) and indicating the persistence of infective oocysts in the environment. Clinical sampling of birds during both years demonstrated positive results from examination of both faecal samples and peripheral blood smears.

Relationship between Eurasian large-scale patterns and regional climate variability over the Black and Baltic Seas

Energy Technology Data Exchange (ETDEWEB)

Stankunavicius, G.; Pupienis, D. [Vilnius Univ. (Lithuania). Dept. of Hydrology and Climatology; Basharin, D. [National Academy of Science of Ukraine, Sevastopol (Ukraine). Sevastopol Marine Hydrophysical Inst.

2012-11-01

Using a NCEP/NCAR Reanalysis dataset and the empirical orthogonal function (EOF) analysis approach we studied interannual to decadal variabilities of the sea-level air pressure (SLP) and the surface air temperature (SAT) fields over Eurasia during the 2nd part of the 20th century. Our results agree with those of the previous studies, which conclude that Eurasian trends are the result of storm-path changes driven by the interdecadal behaviour of the NAO-like meridional dipole pattern in the Atlantic. On interannual and decadal time scales, significant synchronous correlations between correspondent modes of SAT and SLP EOF patterns were found. This fact suggests that there is a strong and stable Eurasian interrelationship between SAT and SLP large-scale fields which affects the local climate of two sub-regions: the Black and Baltic Seas. The climate variability in these sub-regions was studied in terms of Eurasian large-scale surface-temperature and air-pressure patterns responses. We concluded that the sub-regional climate variability substantially differs over the Black and Baltic Seas, and depends on different Eurasian large-scale patterns. We showed that the Baltic Sea region is influenced by the patterns arising primary from NAO-like meridional dipole, as well as Scandinavian patterns, while the Black Sea's SAT/SLP variability is influenced mainly by the second mode EOF (eastern Atlantic) and large scale tropospheric wave structures. (orig.)

Impact of flood on distribution of bathypelagic perch fry layer along the longitudinal profile of large canyon-shaped reservoir

Czech Academy of Sciences Publication Activity Database

Čech, Martin; Kubečka, Jan; Frouzová, Jaroslava; Draštík, Vladislav; Kratochvíl, Michal; Jarošík, Jiří

2007-01-01

Roč. 70, č. 4 (2007), s. 1109-1119 ISSN 0022-1112. [Annual Meeting of the American Fisheries Society /136/. Lake Placid, 10.09.2006-14.09.2006] R&D Projects: GA ČR(CZ) GA206/06/1371 Institutional research plan: CEZ:AV0Z60170517 Keywords : Orlík Reservoir * shoaling * echosounder * cyprinids * Perca fluviatilis * Sander lucioperca Subject RIV: EG - Zoology Impact factor: 1.404, year: 2007

Field-Derived Hydraulic Properties for Perched-Water Aquifer Wells 299-E33-350 and 299-E33-351, Hanford Site B-Complex Area

Energy Technology Data Exchange (ETDEWEB)

Newcomer, Darrell R.

2014-07-01

During February and March 2014, Pacific Northwest National Laboratory conducted hydraulic (slug) tests at 200-DV-1 Operable Unit wells 299-E33-350 (C8914) and 299-E33-351 (C8915) as part of B-Complex Area Perched-Water characterization activities at the Hanford Site 200-East Area. During the construction/completion phase of each well, two overlapping depth intervals were tested within the unconfined perched-water aquifer contained in the silty-sand subunit of the Cold Creek Unit. The purpose of the slug-test characterization was to provide estimates of transmissivity and hydraulic conductivity for the perched-water aquifer at these selected well locations.

Geochemistry and hydrology of perched groundwater springs: assessing elevated uranium concentrations at Pigeon Spring relative to nearby Pigeon Mine, Arizona (USA)

Science.gov (United States)

Beisner, Kimberly R.; Paretti, Nicholas; Tillman, Fred; Naftz, David L.; Bills, Donald; Walton-Day, Katie; Gallegos, Tanya J.

2017-01-01

The processes that affect water chemistry as the water flows from recharge areas through breccia-pipe uranium deposits in the Grand Canyon region of the southwestern United States are not well understood. Pigeon Spring had elevated uranium in 1982 (44 μg/L), compared to other perched springs (2.7–18 μg/L), prior to mining operations at the nearby Pigeon Mine. Perched groundwater springs in an area around the Pigeon Mine were sampled between 2009 and 2015 and compared with material from the Pigeon Mine to better understand the geochemistry and hydrology of the area. Two general groups of perched groundwater springs were identified from this study; one group is characterized by calcium sulfate type water, low uranium activity ratio 234U/238U (UAR) values, and a mixture of water with some component of modern water, and the other group by calcium-magnesium sulfate type water, higher UAR values, and radiocarbon ages indicating recharge on the order of several thousand years ago. Multivariate statistical principal components analysis of Pigeon Mine and spring samples indicate Cu, Pb, As, Mn, and Cd concentrations distinguished mining-related leachates from perched groundwater springs. The groundwater potentiometric surface indicates that perched groundwater at Pigeon Mine would likely flow toward the northwest away from Pigeon Spring. The geochemical analysis of the water, sediment and rock samples collected from the Snake Gulch area indicate that the elevated uranium at Pigeon Spring is likely related to a natural source of uranium upgradient from the spring and not likely related to the Pigeon Mine.

Mercury and water level fluctuations in lakes of northern Minnesota

Science.gov (United States)

Larson, James H.; Maki, Ryan P; Christensen, Victoria G.; Sandheinrich, Mark B.; LeDuc, Jaime F.; Kissane, Claire; Knights, Brent C.

2017-01-01

Large lake ecosystems support a variety of ecosystem services in surrounding communities, including recreational and commercial fishing. However, many northern temperate fisheries are contaminated by mercury. Annual variation in mercury accumulation in fish has previously been linked to water level (WL) fluctuations, opening the possibility of regulating water levels in a manner that minimizes or reduces mercury contamination in fisheries. Here, we compiled a long-term dataset (1997-2015) of mercury content in young-of-year Yellow Perch (Perca flavescens) from six lakes on the border between the U.S. and Canada and examined whether mercury content appeared to be related to several metrics of WL fluctuation (e.g., spring WL rise, annual maximum WL, and year-to-year change in maximum WL). Using simple correlation analysis, several WL metrics appear to be strongly correlated to Yellow Perch mercury content, although the strength of these correlations varies by lake. We also used many WL metrics, water quality measurements, temperature and annual deposition data to build predictive models using partial least squared regression (PLSR) analysis for each lake. These PLSR models showed some variation among lakes, but also supported strong associations between WL fluctuations and annual variation in Yellow Perch mercury content. The study lakes underwent a modest change in WL management in 2000, when winter WL minimums were increased by about 1 m in five of the six study lakes. Using the PLSR models, we estimated how this change in WL management would have affected Yellow Perch mercury content. For four of the study lakes, the change in WL management that occurred in 2000 likely reduced Yellow Perch mercury content, relative to the previous WL management regime.

Croatian Ethnogenesis: A Review of Component Stages and Interpretations (with Emphasis on Eurasian/Nomadic Elements

Directory of Open Access Journals (Sweden)

Emil Heršak

2007-09-01

Full Text Available In the paper, the authors present certain parameters dealing with the nomadic element, or possible indications of it, in Croatian ethnogenesis. First, a comment is given on the ethnogenetic concept itself, and a working definition of ethnogenesis is suggested. Second, the major components that are considered to have had a role in Croatian ethnogenesis are listed. This discussion is followed by an identification of those elements that could somehow be considered nomadic, or else representative of influences from the Eurasian steppe region. Mention is made of historical sources that confirm or imply the presence of Eurasian nomad groups in the Croatian area, and the relative frequency of archaeological material is noted. The authors analise views of previous and present Croatian and foreign authors on Croatian ethnogenesis, especially in regard to the “Eurasian connection”. In this part of the discussion, the Iranian theory of Croat origins is presented in more detail. Finally, the authors briefly address recent genetic (DNA analyses of the contemporary Croatian population.

Benefit-cost analysis of fishery rehabilitation projects: A Great Lakes case study. Spec. issue: Responses to marine resource change/social sciences perspective

Science.gov (United States)

Bishop, R.C.; Milliman, S.R.; Boyle, K.J.; Johnson, B.L.

1990-01-01

Tools of benefit-cost analysis are used to evaluate a project to rehabilitate the yellow perch (Perca flavescens ) fishery of Green Bay, Wisconsin. Both sport and commercial fishers harvest from this stock, which has been suffering from much reduced productivity since the early 1960s. The project is composed of commercial quotas and other regulations. Measures of benefits and costs were used that explicitly incorporate uncertainly about the potential level of success of the project. The analysis shows that commercial fish producers will more or less break even compared to where they would have been without the project, but that substantial recreational benefits can be expected.

Voluntary angler logbooks reveal long-term changes in a lentic pike, Esox lucius, population

DEFF Research Database (Denmark)

Jansen, Teunis; Arlinghaus, R.; Als, Thomas Damm

2013-01-01

Sixty-two years of voluntarily collected angling logbook data from a large natural Danish lake were used to 2 study variation in pike, Esox lucius L., CPUE (expressed as no. of captured per boat trip) as an index of stock size. Pike CPUE was positively related to pike release rate by anglers...... and negatively affected by certain commercial shers. The stocking of young-of-the-year pike and a shery-dependent index of perch, Perca uviatilis L., abundance (which may be pike prey or predator depending on size) did not correlate with pike CPUE. Analyses of the size distribution of pike, based on sizes...

Introducing a new Book on the Ural-Altaic Language Classification (Towards Eurasian Linguistic Isoglosses: the Case of Turkic and Hungarian)

NARCIS (Netherlands)

Marácz, L.

2014-01-01

In this article, László Marácz introduces his own book on a new approach to the Ural-Altaic language classification. The book entitled ‘Towards Eurasian Linguistic Isoglosses: the Case of Hungarian and Turkic’ (henceforth ‘Towards Eurasian Linguistic Isoglosses…’ abbreviated as TELI) develops a

Enhancing effect of spawning on elimination of a persistent polychlorinated biphenyl from female yellow perch

International Nuclear Information System (INIS)

Vodicnik, M.J.; Peterson, R.E.

1985-01-01

Distribution and elimination of 2,5,2',5'-tetrachloro[14C]biphenyl (4-CB) were studied for 6 months after exposing sexually mature female yellow perch to the compound in water and transferring them to flowing 4-CB-free water. Perch that were exposed in January spawned in May, and the study was terminated in June. During the first 41/2 months after exposure, the t1/2 for whole-body elimination was 22 weeks, primarily by elimination of 4-CB from the viscera and carcass. During spawning, enhanced elimination (t1/2 less than 0.7 weeks) was due to the voiding of eggs containing 4-CB. After spawning, whole-body elimination returned to a slower rate (t1/2 = 16.3 weeks). Prior to the enhancement in 4-CB elimination rate during spawning, there was a redistribution of 4-CB residues within the body of the perch which was characterized by a transfer of 4-CB residues from primarily the carcass and viscera to eggs. Two weeks after exposure, 30% of the initial 4-CB body burden was distributed to the eggs, whereas just prior to spawning, about 50% was present in this tissue. These findings demonstrate that egg maturation and spawning result in a significant reduction in the body burden of a persistent polychlorinated biphenyl in a lean-fish species

Effects of oil production on economic growth in Eurasian countries: Panel ARDL approach

International Nuclear Information System (INIS)

Bildirici, Melike Elif; Kayıkçı, Fazıl

2013-01-01

This study aims at analyzing the relationship between oil production and economic growth in major oil exporting Eurasian countries; Azerbaijan, Kazakhstan, Russian Federation and Turkmenistan for 1993–2010 periods. Empirical results reveal that oil production and economic growth are cointegrated for these countries. Furthermore, there is positive bi-directional causality between oil production and economic growth both in the long run and in the short run which supports the policies about investing in energy infrastructure. -- Highlights: ► Causality between economic growth and oil production is important for energy policies. ► Oil production and GDP are cointegrated for four oil exporting Eurasian countries. ► There is positive bi-directional causality between oil production and economic growth for these countries.

Plant species occurrence patterns in Eurasian grasslands reflect adaptation to nutrient ratios

NARCIS (Netherlands)

Roeling, Ineke S.; Ozinga, Wim A.; van Dijk, Jerry; Eppinga, Maarten B.; Wassen, Martin J.

2018-01-01

Previous studies of Eurasian grasslands have suggested that nutrient ratios, rather than absolute nutrient availabilities and associated productivity, may be driving plant species richness patterns. However, the underlying assumption that species occupy distinct niches along nutrient ratio gradients

Song repertoire size correlates with measures of body size in Eurasian blackbirds

DEFF Research Database (Denmark)

Hesler, Nana; Mundry, Roger; Sacher, Thomas

2012-01-01

In most oscine bird species males possess a repertoire of different song patterns. The size of these repertoires is assumed to serve as an honest signal of male quality. The Eurasian blackbird’s (Turdus merula) song contains a large repertoire of different element types with a flexible song...... organisation. Here we investigated whether repertoire size in Eurasian blackbirds correlates with measures of body size, namely length of wing, 8th primary, beak and tarsus. So far, very few studies have investigated species with large repertoires and a flexible song organisation in this context. We found...... positive correlations, meaning that larger males had larger repertoires. Larger males may have better fighting abilities and, thus, advantages in territorial defence. Larger structural body size may also reflect better conditions during early development. Therefore, under the assumption that body size...

Evidence for discrete subpopulations of sea perch (Helicolenus ercoides) across four fjords in Fiordland, New Zealand

International Nuclear Information System (INIS)

Lawton, R.J.; Wing, S.R.; Lewis, A.M.

2010-01-01

In coastal populations of invertebrates and fishes, the distribution of discrete subpopulations is influenced by adult and larval dispersal, as well as by the effects of habitat heterogeneity on site fidelity or connectivity. Here, we examine evidence for spatial structure of sea perch, Helicolenus percoides, populations among four fjords in the Fiordland region of southwestern New Zealand. We examine patterns in adult morphology, length-at-age, δ 13 C and δ 15 N of muscle tissue, and trace elemental composition of whole otoliths as proxies for population isolation among the four inner fjord regions. A multivariate analysis of morphometrics reveals significant differences among populations from each of the four sites, suggesting existence of four distinct subpopulations. These patterns are consistent with observed differences in δ 13 C and δ 15 N, and length-at-age estimates among the four subpopulations. Differences in whole otolith concentrations of Sr, Ba, Mg and Li, and high classification scores based on the whole otolith elemental fingerprint are also consistent with significant subdivision among areas. Patterns across all four markers are consistent with discrete subpopulation structure of adult sea perch among the four study sites. These data indicate that the newly implemented network of marine protected areas in Fiordland is likely to contain discrete populations of sea perch. (author).

The Eurasian beaver (Castor fiber) is apparently not a host to blood parasites in Norway.

Science.gov (United States)

Cross, Hannah B; Campbell-Palmer, Róisín; Girling, Simon; Rosell, Frank

2012-11-23

Parasites can alter the physiology and behaviour of host species and negatively impact on their fitness thus affecting population densities. This is the first investigation into the presence of blood parasites in the Eurasian beaver (Castor fiber); a species that has been the subject of many translocation and reintroduction programmes. Two hundred and seventy blood slides prepared from the blood of 27 beavers from southern Norway were microscopically analysed for the presence of blood parasites. This study reports an absence of blood parasites in the Norwegian Eurasian beavers sampled. Copyright © 2012 Elsevier B.V. All rights reserved.

Isolation of an iridovirus from pike-perch Stizostedion lucioperca

DEFF Research Database (Denmark)

Tapiovaara, H.; Olesen, Niels Jørgen; Linden, J.

1998-01-01

We have isolated a large virus from pike-perch Stizostedion lucioperca fingerlings with no signs of disease. The biochemical, structural, and serological properties of this newly isolated virus suggest that it belongs to the family Iridoviridae. The virus multiplied and was cytopathogenic...... fish iridoviruses. It is an enveloped icosahedral DNA virus. The diameter of the nucleocapsid in thin sections was 127 +/- 3 nm; in negatively stained preparates the size of the enveloped virus varied from 147 to 187 nm. In immunofluorescence the virus was stained by rabbit antisera against EHN...

Dietary specialization during the evolution of Western Eurasian hominoids and the extinction of European Great Apes.

Directory of Open Access Journals (Sweden)

Daniel DeMiguel

Full Text Available Given the central adaptive role of diet, paleodietary inference is essential for understanding the relationship between evolutionary and paleoenvironmental change. Here we rely on dental microwear analysis to investigate the role of dietary specialization in the diversification and extinction of Miocene hominoids from Western Eurasian between 14 and 7 Ma. New microwear results for five extinct taxa are analyzed together with previous data for other Western Eurasian genera. Except Pierolapithecus (that resembles hard-object feeders and Oreopithecus (a soft-frugivore probably foraging opportunistically on other foods, most of the extinct taxa lack clear extant dietary analogues. They display some degee of sclerocarpy, which is most clearly expressed in Griphopithecus and Ouranopithecus (adapted to more open and arid environments, whereas Anoiapithecus, Dryopithecus and, especially, Hispanopithecus species apparently relied more strongly on soft-frugivory. Thus, contrasting with the prevailing sclerocarpic condition at the beginning of the Eurasian hominoid radiation, soft- and mixed-frugivory coexisted with hard-object feeding in the Late Miocene. Therefore, despite a climatic trend towards cooling and increased seasonality, a progressive dietary diversification would have occurred (probably due to competitive exclusion and increased environmental heterogeneity, although strict folivory did not evolve. Overall, our analyses support the view that the same dietary specializations that enabled Western Eurasian hominoids to face progressive climatic deterioration were the main factor ultimately leading to their extinction when more drastic paleoenvironmental changes took place.

Reappraising factors affecting mourning dove perch coos

Science.gov (United States)

Sayre, M.W.; Atkinson, R.D.; Baskett, T.S.; Haas, G.H.

1978-01-01

Results confirmed pairing as the primary factor influencing perch-cooing rates of wild mourning doves (Zenaida macroura). Marked unmated males cooed at substantially higher rates (6.2x) than mated males, had greater probability of cooing (2.3x) during 3-minute periods, and continued cooing longer each morning than mated males. Population density was not a major factor affecting cooing. Unmated males cooed more frequently in the presence of other cooing doves (P < 0.05) than when alone, but the number of additional doves above 1 was unimportant. Cooing rates of both mated and unmated males on areas with dissimilar dove densities were not significantly different. Within limits of standard call-count procedure, weather exerted no detectable influence on cooing.

Genetic diversity in India and the inference of Eurasian population expansion.

Science.gov (United States)

Xing, Jinchuan; Watkins, W Scott; Hu, Ya; Huff, Chad D; Sabo, Aniko; Muzny, Donna M; Bamshad, Michael J; Gibbs, Richard A; Jorde, Lynn B; Yu, Fuli

2010-01-01

Genetic studies of populations from the Indian subcontinent are of great interest because of India's large population size, complex demographic history, and unique social structure. Despite recent large-scale efforts in discovering human genetic variation, India's vast reservoir of genetic diversity remains largely unexplored. To analyze an unbiased sample of genetic diversity in India and to investigate human migration history in Eurasia, we resequenced one 100-kb ENCODE region in 92 samples collected from three castes and one tribal group from the state of Andhra Pradesh in south India. Analyses of the four Indian populations, along with eight HapMap populations (692 samples), showed that 30% of all SNPs in the south Indian populations are not seen in HapMap populations. Several Indian populations, such as the Yadava, Mala/Madiga, and Irula, have nucleotide diversity levels as high as those of HapMap African populations. Using unbiased allele-frequency spectra, we investigated the expansion of human populations into Eurasia. The divergence time estimates among the major population groups suggest that Eurasian populations in this study diverged from Africans during the same time frame (approximately 90 to 110 thousand years ago). The divergence among different Eurasian populations occurred more than 40,000 years after their divergence with Africans. Our results show that Indian populations harbor large amounts of genetic variation that have not been surveyed adequately by public SNP discovery efforts. Our data also support a delayed expansion hypothesis in which an ancestral Eurasian founding population remained isolated long after the out-of-Africa diaspora, before expanding throughout Eurasia. © 2010 Xing et al.; licensee BioMed Central Ltd.

How autumn Eurasian snow anomalies affect east asian winter monsoon: a numerical study

Science.gov (United States)

Luo, Xiao; Wang, Bin

2018-03-01

Previous studies have found that snow Eurasian anomalies in autumn can affect East Asian winter monsoon (EAWM), but the mechanisms remain controversial and not well understood. The possible mechanisms by which Eurasian autumn snow anomalies affect EAWM are investigated by numerical experiments with a coupled general circulation model and its atmospheric general circulation model component. The leading empirical orthogonal function mode of the October-November mean Eurasian snow cover is characterized by a uniform anomaly over a broad region of central Eurasia (40°N-65°N, 60°E-140°E). However, the results from a 150-ensemble mean simulation with snow depth anomaly specified in October and November reveal that the Mongolian Plateau and Vicinity (MPV, 40°-55°N, 80°-120°E) is the key region for autumn snow anomalies to affect EAWM. The excessive snow forcing can significantly enhance EAWM and the snowfall over the northwestern China and along the EAWM front zone stretching from the southeast China to Japan. The physical process involves a snow-monsoon feedback mechanism. The excessive autumn snow anomalies over the MPV region can persist into the following winter, and significantly enhance winter snow anomalies, which increase surface albedo, reduce incoming solar radiation and cool the boundary layer air, leading to an enhanced Mongolian High and a deepened East Asian trough. The latter, in turn, strengthen surface northwesterly winds, cooling East Asia and increasing snow accumulation over the MPV region and the southeastern China. The increased snow covers feedback to EAWM system through changing albedo, extending its influence southeastward. It is also found that the atmosphere-ocean coupling process can amplify the delayed influence of Eurasian snow mass anomaly on EAWM. The autumn surface albedo anomalies, however, do not have a lasting "memory" effect. Only if the albedo anomalies are artificially extended into December and January, will the EAWM be

Effects of fasting, temperature, and photoperiod on preproghrelin mRNA expression in Chinese perch.

Science.gov (United States)

Song, Yi; Zhao, Cheng; Liang, Xu-Fang; He, Shan; Tian, Changxu; Cheng, Xiaoyan; Yuan, Xiaochen; Lv, Liyuan; Guo, Wenjie; Xue, Min; Tao, Ya-Xiong

2017-06-01

Preproghrelin, a gut/brain peptide, plays an important role in the regulation of food intake and energy homeostasis in teleost and mammals. In the present study, we obtained the full-length preproghrelin cDNA in Chinese perch. The preproghrelin messenger RNA (mRNA) tissue expression showed that level was much higher in stomach and pituitary than in other tissues. The fasting study showed, after gastric emptying (3-6 h), short-term fasting (6-12 h) increased preproghrelin expression in the stomach. While in the pituitary, fasting reduced preproghrelin expression at 1, 3, 12, and 48 h, presenting state fluctuation of self-adjustment. The temperature study showed that the mRNA expression of preproghrelin was the highest in the brain at 26 °C and highest in the stomach at 32 °C, respectively, with different optimum temperature in these two tissues, reflecting spatiotemporal differences of regulation by central nervous system and peripheral organs. The photoperiod study showed that normal light (11 h of lightness and 13 h of darkness) led to highest preproghrelin expression, both in the brain and in the stomach, than continuous light or continuous dark, proving food intake is adapted to natural photoperiod or normal light in this study. These results all indicated that tissue-specific preproghrelin expression of Chinese perch could be significantly affected by environmental factors. Short-term fasting of 6 h after gastric emptying, 26 °C, and normal light led to higher preproghrelin expression, which indicated potential appetite increase in Chinese perch.

The use of genetic methods to study Eurasian otters

Czech Academy of Sciences Publication Activity Database

Hájková, Petra; Gettová, Lenka; Sládkovičová, V.; Zemanová, Barbora

Supp., - (2011), s. 102 ISSN 0394-1914. [International Otter Colloquium /11./. 30.08.2011-04.09.2011, Pavia] R&D Projects: GA AV ČR KJB600930804; GA MŽP SP/2D4/16/08; GA ČR GA206/03/0757 Institutional research plan: CEZ:AV0Z60930519 Keywords : Eurasian otter * genetic analyses Subject RIV: EG - Zoology http://www.internationalottercolloquium2010.eu/files/proceedings_iucn_xi_ioc_2011.pdf

Characterization of Newcastle disease virus isolates obtained from Eurasian collared doves (Streptopelia decaocto) in Italy.

Science.gov (United States)

Terregino, Calogero; Cattoli, Giovanni; Grossele, Barbara; Bertoli, Elena; Tisato, Ernesto; Capua, Ilaria

2003-02-01

Eurasian collared doves (Streptopelia decaocto) are thought to originate from India and they have colonized, throughout the centuries, the Middle East and, more recently, Mediterranean countries such as Italy and Spain. In the present paper we report of the isolation and characterization of Newcastle disease viruses (NDV) obtained from Eurasian collared doves during 2000-2001, and compare them to isolates obtained from feral pigeons (Columba livia) during the same period. All isolates could be classified as avian paramyxovirus type 1 (APMV1) and belonged to the pigeon variant group (PPMV1), as their haemagglutinating activity was inhibited by mAb 161/617 which is specific for PPMV1. The intracerebral pathogenicity indices ranged from 0.68 to 1.38 and all isolates contained multiple basic amino acids at the deduced cleavage site of the fusion protein, which is a typical feature of virulent viruses. Phylogenetic analysis of the isolates indicate that 18/20 of these form a separate cluster from the isolates obtained from pigeons in the same period. These findings suggest that different lineages are circulating in feral pigeon populations, and that a separate lineage affects Eurasian collared doves.

MtDNA genetic diversity and structure of Eurasian Collared Dove (Streptopelia decaocto).

Science.gov (United States)

Bagi, Zoltán; Dimopoulos, Evangelos Antonis; Loukovitis, Dimitrios; Eraud, Cyril; Kusza, Szilvia

2018-01-01

The Eurasian Collared Dove (Streptopelia decaocto) is one of the most successful biological invaders among terrestrial vertebrates. However, little information is available on the genetic diversity of the species. A total of 134 Eurasian Collared Doves from Europe, Asia and the Caribbean (n = 20) were studied by sequencing a 658-bp length of mitochondrial DNA (mtDNA) cytochrome oxidase I (COI). Fifty-two different haplotypes and relatively high haplotype and nucleotide diversities (Hd±SD = 0.843±0.037 and π±SD = 0.026±0.013) were detected. Haplotype Ht1 was particularly dominant: it included 44.03% of the studied individuals, and contained sequences from 75% of the studied countries. Various analyses (FST, AMOVA, STRUCTURE) distinguished 2 groups on the genetic level, designated 'A' and 'B'. Two groups were also separated in the median-joining network and the maximum likelihood tree. The results of the neutrality tests were negative (Fu FS = -25.914; Tajima D = -2.606) and significantly different from zero (P≤0.001) for group A, whereas both values for group B were positive (Fu FS = 1.811; Tajima D = 0.674) and not significant (P>0.05). Statistically significant positive autocorrelation was revealed among individuals located up to 2000 km apart (r = 0.124; P = 0.001). The present results provide the first information on the genetic diversity and structure of the Eurasian Collared Dove, and can thereby serve as a factual and comparative basis for similar studies in the future.

Radiological investigation of roach and perch from some lakes in Lithuania

International Nuclear Information System (INIS)

Cepanko, V.; Idzelis, R. L.; Kesminas, V.; Lydagiene, R.

2006-01-01

From the point of view of biological toxicity the most toxic radionuclides are man-made 90 Sr and 137 Cs because the behaviour of both of them is similar to stable calcium and potassium in the body. Fish is the last part of the hydro system chain which accumulates pollutants. The aim of this study was to analyse the distribution of these two radionuclides in the muscle and other organs of perch and roach that differ by age and living conditions. Measurements were performed for 137 Cs and 90 Sr activity concentrations in fishes from the lakes of Druksiai, Lukstas and Dusia. Radioecological investigation was carried out for different age groups of roach and perch analysing samples of muscle and spine bones (including the head of fish). Radioecological investigation of fishes from the lakes of Druksiai, Lukstas and Dusia show that the activity concentrations of 137 Cs and 90 Sr are low. Anyway, the accumulated radioactivity by food chain reaches the human body. Nowadays a lot of investigations are related to the lakes in the vicinity of Ignalina NPP. The investigation shows that the activity concentrations of 137 Cs and 90 Sr in fishes from the Druksiai lake are the same as in fishes from other lakes in other locations of Lithuania. (author)

Bone-remodeling transcript levels are independent of perching in end-of-lay white leghorn chickens.

Science.gov (United States)

Dale, Maurice D; Mortimer, Erin M; Kolli, Santharam; Achramowicz, Erik; Borchert, Glenn; Juliano, Steven A; Halkyard, Scott; Sietz, Nick; Gatto, Craig; Hester, Patricia Y; Rubin, David A

2015-01-23

Osteoporosis is a bone disease that commonly results in a 30% incidence of fracture in hens used to produce eggs for human consumption. One of the causes of osteoporosis is the lack of mechanical strain placed on weight-bearing bones. In conventionally-caged hens, there is inadequate space for chickens to exercise and induce mechanical strain on their bones. One approach is to encourage mechanical stress on bones by the addition of perches to conventional cages. Our study focuses on the molecular mechanism of bone remodeling in end-of-lay hens (71 weeks) with access to perches. We examined bone-specific transcripts that are actively involved during development and remodeling. Using real-time quantitative PCR, we examined seven transcripts (COL2A1 (collagen, type II, alpha 1), RANKL (receptor activator of nuclear factor kappa-B ligand), OPG (osteoprotegerin), PTHLH (PTH-like hormone), PTH1R (PTH/PTHLH type-1 receptor), PTH3R (PTH/PTHLH type-3 receptor), and SOX9 (Sry-related high mobility group box)) in phalange, tibia and femur. Our results indicate that the only significant effect was a difference among bones for COL2A1 (femur > phalange). Therefore, we conclude that access to a perch did not alter transcript expression. Furthermore, because hens have been used as a model for human bone metabolism and osteoporosis, the results indicate that bone remodeling due to mechanical loading in chickens may be a product of different pathways than those involved in the mammalian model.

Central Asian gas in Eurasian power game

International Nuclear Information System (INIS)

Cobanli, Onur

2014-01-01

Following the dissolution of the Soviet Union, various gas pipeline projects have been proposed to diversify transit routes and export markets of the landlocked Central Asian states. To evaluate the pipeline project's impact on the players' bargaining power, I apply the cooperate game theory to a quantitative model of the Eurasian gas trade and quantify the bargaining power structure via the Shapley value. Due to ample production capacities in Central Asia, I observe little strategic interaction between the West and China. Thus, demand competition with China is not necessarily a disadvantage for the West, and the Turkmenistan–China pipeline does not affect the impact of the westbound projects aiming Europe and Turkey. For Turkmenistan, i.e., the main supplier in the region, a link via the Caspian Sea to Turkey is the most beneficial westbound option. Although the projects carrying gas from Azerbaijan and Turkmenistan to Europe enjoy the European Commission's political support, they yield marginal benefits to the European consumers. Thanks to its transit position, Turkey collects a large share of the benefits in the East–West gas trade. - Highlights: • The Eurasian gas trade is represented as a cooperative game which is solved with the Shapley value. • There is no demand competition between the West and China for Central Asian gas. • For Turkmenistan the route via the Caspian Sea is the most beneficial westbound pipeline option. • Turkey emerges as a transit country and collects a large share of the benefits from the East–West gas trade. • A link to Europe yields marginal benefits to Turkmenistan and Europe

Comparison of nutritional quality in fish maw product of croaker Protonibea diacanthus and perch Lates niloticus

Science.gov (United States)

Wen, Jing; Zeng, Ling; Chen, Ziming; Xu, Youhou

2016-08-01

Fish maw (the dried swimbladders of fish) is ranked in the list of the four sea treasures in Chinese cuisine. Fish maw is mainly produced from croaker, which is the most highly priced. However, some of the fish maw being sold as croaker maw are in fact not from croaker, but from the Nile perch Lates niloticus. The present work determined and compared the proximate composition, amino acid and fatty acid composition of croaker Protonibea diacanthus maw and perch L. niloticus maw. The results indicated that both maws were high protein sources and low in fat content. The dominant amino acids in both maws were glycine, proline, glutamic acid, alanine and arginine. These amino acids constituted 66.2% and 66.4% of the total amino acids in P. diacanthus and L. niloticus, respectively. The ratio of FAA: TAA (functional amino acids: total amino acids) in both maws were 0.69. This is a good explanation for why fish maws have been widely utilized as a traditional tonic and remedy in Asia. Except valine and histidine, all the essential amino acid contents in P. diacanthus were higher than in L. niloticus. Moreover, croaker P. diacanthus maw contained more AA and DHA than perch L. niloticus maw, showing a higher ratio of n-3 / n-6, which is more desirable.

Changes in fish mercury concentrations over 20 years in an acidified lake subject to experimental liming

International Nuclear Information System (INIS)

Rask, Martti; Jones, Roger I.; Jaervinen, Marko; Paloheimo, Anna; Salonen, Maiju; Syvaeranta, Jari; Verta, Matti

2007-01-01

Lake Iso Valkjaervi (southern Finland, Europe) was divided in two with a plastic curtain in 1991. One half was neutralized with CaCO 3 , and the other acted as a control. Mercury concentrations of perch (Perca fluviatilis) and northern pike (Esox lucius) in the limed and control side of the lake were studied both before and after the treatment. Average Hg concentrations of perch and pike were 0.40 and 1.2 μg g -1 (ww) in the early 1980s and 0.25 and 0.72 μg g -1 (ww) a decade later at the time of liming. Ten years after the liming the Hg concentrations of perch in the limed and control sides of the lake were 0.21 and 0.28 μg g -1 (ww) and those of pike were 0.69 and 0.43 μg g -1 (ww), respectively. Nitrogen isotope ratios (δ 15 N) for perch in the sampling period 2002-2004 showed wide variation suggesting variable trophic positions for individual fish. Pike formed two groups according to their δ 15 N-values, suggesting that zoobenthos dominated the diet of pike around 20 cm in length and fish that of the larger pikes. Because the δ 15 N-values of fish were at similar levels in the limed and control sides of L. Iso Valkjaervi, differences in food web structure cannot account for the different fish Hg concentrations. A more likely explanation is water quality induced differences in the dynamics and bioavailability of Hg, leading to decreased formation of methyl Hg

Impact of the keystone species, the Eurasian beaver (Castor fiber), on habitat structure and its significance to mammals

OpenAIRE

Samas, Arūnas

2016-01-01

Eurasian beaver (Castor fiber), the representative of the family Castoridae, which includes two living species of the genus Castor. Beavers are the keystone species, also deservedly known as the ecosystem engineer for the ability to create new habitats and to change the existing landscape. Biology of the Eurasian beaver is well studied, but still, there is a lack of knowledge about the ecology of the species - the relationship with the surrounding environment and biota. These studies were car...

Digestion and metabolism of carbohydrates in fish

OpenAIRE

Abro, Rani

2014-01-01

This thesis deals with the digestion and metabolism of carbohydrates in Arctic charr, Eurasian perch and tilapia. Two sources of carbohydrates, native starch (wheat) and chitin (zygomycete biomass), were evaluated. Gut tissue of Arctic charr displayed significant chitinase activity, of both endo- and exo-chitinase forms. Moreover, the distribution pattern along the gastrointestinal tract of Arctic charr differed between endo-chitinase and exo-chitinase. The endo-chitinase activity in sto...

Approaches to the simulation of unconfined flow and perched groundwater flow in MODFLOW

Science.gov (United States)

Bedekar, Vivek; Niswonger, Richard G.; Kipp, Kenneth; Panday, Sorab; Tonkin, Matthew

2012-01-01

Various approaches have been proposed to manage the nonlinearities associated with the unconfined flow equation and to simulate perched groundwater conditions using the MODFLOW family of codes. The approaches comprise a variety of numerical techniques to prevent dry cells from becoming inactive and to achieve a stable solution focused on formulations of the unconfined, partially-saturated, groundwater flow equation. Keeping dry cells active avoids a discontinuous head solution which in turn improves the effectiveness of parameter estimation software that relies on continuous derivatives. Most approaches implement an upstream weighting of intercell conductance and Newton-Raphson linearization to obtain robust convergence. In this study, several published approaches were implemented in a stepwise manner into MODFLOW for comparative analysis. First, a comparative analysis of the methods is presented using synthetic examples that create convergence issues or difficulty in handling perched conditions with the more common dry-cell simulation capabilities of MODFLOW. Next, a field-scale three-dimensional simulation is presented to examine the stability and performance of the discussed approaches in larger, practical, simulation settings.

Integration Dilemma within the Eurasian Space in the Context of the Ukrainian Crisis

Directory of Open Access Journals (Sweden)

Antonina A. Durdyeva

2015-01-01

Full Text Available The article analyses the reaction of top officials, politicians and representatives of the expert community of the Eurasian Economic Union member countries on the aggravation of "Ukrainian crisis" in the context of plans and directions for further Eurasian integration. Today, in the scientific community is becoming a popular" dilemma of integration " as a systematic pattern that determines the development of relations between the integration associations. The dilemma of integration is a political phenomenon, a regular and predictable. Ukrainian crisis, which has become a litmus test of conflict of representations of the CIS countries on the extent and depth of their involvement in the processes of regional integration , most clearly outlined the presence of such dilemma within the CIS. In the current situation for Belarus and Kazakhstan as two , along with Russia , the main designers of the Eurasian field, the dilemma of integration takes a fundamentally different meaning and becomes a so-called "Dilemma of integrations", or contradiction between the desire of these countries to secure the most favorable conditions in its relations with Moscow and reluctance to fully bear the burden of the costs and constraints arising in relations with the EU due to the commitments of the EAEC. Based on the material of the official position of the representatives of Republic of Kazakhstan and the Republic of Belarus the author of the article explores the implications of the Ukrainian crisis in relations of Three: Moscow, Astana and Minsk.

Using plasma-fuel systems at Eurasian coal-fired thermal power stations

Science.gov (United States)

Karpenko, E. I.; Karpenko, Yu. E.; Messerle, V. E.; Ustimenko, A. B.

2009-06-01

The development of plasma technology for igniting solid fuels at coal-fired thermal power stations in Russia, Kazakhstan, China, and other Eurasian countries is briefly reviewed. Basic layouts and technical and economic characteristics of plasma-fuel systems installed in different coal-fired boiles are considered together with some results from using these systems at coal-fired thermal power stations.

Application of fractional factorial design to improve hot smoked Nile Perch (Lates niloticus quality

Directory of Open Access Journals (Sweden)

Sokamté, T.A.

2017-06-01

Full Text Available The aim of this research was to study the parameters influencing moisture, salt and total phenol content of hot smoked Nile Perch and to compare the influence of processing conditions on its proximate composition and sensory quality. The effect on moisture, salt and total phenol content was investigated using fractional factorial design with seven factors and two levels: X1 for brine concentration, X2 for brining time, X3 for preliminary smoking-drying time, X4 for smoking time, X5 for hot smoking time, X6 for smoking temperature and X7 for hot smoking temperature. A Multiple Linear Regression Analysis was performed to fit the mathematical model to the collected data and the model tested using analysis of variance (ANOVA. Results of ANOVA indicated the good accuracy and highest significance of the mathematical model. The range of total protein and lipid content was 17.96 to 34.34% and 0.87 to 4.43%, respectively. The range of general acceptability of smoked Nile Perch was 4.6 to 8.2 based on 9-point hedonic scale. Based on the results obtained, including the overall acceptability, proximate composition and smoking criteria of finished product, samples produced with the following conditions: brining at 4% for 270min, drying at 30°C for 30min and the smoked time/temperature cycles following: 30°C/120min; 50°C/240min and 80°C/240min was the best and most accepted. The results derived from this study indicate that the fractional factorial design is a useful screening tool for improving industrial smoking process of Nile Perch.

Extraction and Production of Omega-3 from UniMAP Puyu (Jade Perch) and Mackarel

Science.gov (United States)

Nur Izzati, I.; Zainab, H.; Nornadhiratulhusna, M.; Chee Hann, Y.; Khairunissa Syairah, A. S.; Amira Farzana, S.

2018-03-01

Extraction techniques to extract fish oil from various types of fish are numerous but not widely accepted because of the use of chemicals that may be harmful to health. In this study, fish oil is extracted using a technique of Microwave-Assisted Extraction, which uses only water. The optimum conditions required for the production of fish oil for extraction is carried out by examining three parameters such as microwave power (300-700W), extraction time (10-30 min) and amount of water used (70-190ml). Optimum conditions were determined after using design of experiments (DOE). The optimum condition obtained was 300 W for microwave power, 10 minutes extraction time and 190 milliliter amounts of water used. Fourier transform infrared spectroscopy (FTIR) was used to analyze the functional groups of fish oil. Two types of fish such as Jade Perch or UniMAP Puyu and Indian Mackerel were used. A standard omega-3 oil sample (Blackmores) purchased from pharmacy was also determined to confirm the presence of omega-3 oil in these fishes. Similar compounds were present in Jade Perch and Indian Mackerel as compared to the standard. Therefore, there were presence of omega-3 fish oil in the two types of fish. From this study, omega-3 in UniMAP Puyu fish was higher compared to Indian Mackerel fish. However, based on the FTIR analysis, besides the presence of omega-3, the two fishes also contain other functional groups such as alkanes, alkenes, aldehyde, ketones and many others. The yield of fish oil for the Jade Perch was low compared to Indian Mackerel which was 9% while Indian Mackerel was 10 %.

Echolocation intensity and directionality of perching and flying fringe-lipped bats, Trachops cirrhosus (Phyllostomidae)

DEFF Research Database (Denmark)

Surlykke, Annemarie; Jakobsen, Lasse; Kalko, Elisabeth K V

2013-01-01

The Neotropical frog-eating bat, Trachops cirrhosus, primarily hunts stationary prey, either by gleaning on the wing, or in a sit-and-wait mode hanging from a perch. It listens passively for prey-generated sounds, but uses echolocation in all stages of the hunt. Like other bats in the family...

Bone-Remodeling Transcript Levels Are Independent of Perching in End-of-Lay White Leghorn Chickens

Directory of Open Access Journals (Sweden)

Maurice D. Dale

2015-01-01

Full Text Available Osteoporosis is a bone disease that commonly results in a 30% incidence of fracture in hens used to produce eggs for human consumption. One of the causes of osteoporosis is the lack of mechanical strain placed on weight-bearing bones. In conventionally-caged hens, there is inadequate space for chickens to exercise and induce mechanical strain on their bones. One approach is to encourage mechanical stress on bones by the addition of perches to conventional cages. Our study focuses on the molecular mechanism of bone remodeling in end-of-lay hens (71 weeks with access to perches. We examined bone-specific transcripts that are actively involved during development and remodeling. Using real-time quantitative PCR, we examined seven transcripts (COL2A1 (collagen, type II, alpha 1, RANKL (receptor activator of nuclear factor kappa-B ligand, OPG (osteoprotegerin, PTHLH (PTH-like hormone, PTH1R (PTH/PTHLH type-1 receptor, PTH3R (PTH/PTHLH type-3 receptor, and SOX9 (Sry-related high mobility group box in phalange, tibia and femur. Our results indicate that the only significant effect was a difference among bones for COL2A1 (femur > phalange. Therefore, we conclude that access to a perch did not alter transcript expression. Furthermore, because hens have been used as a model for human bone metabolism and osteoporosis, the results indicate that bone remodeling due to mechanical loading in chickens may be a product of different pathways than those involved in the mammalian model.

Putin's and Russian-led Eurasian Economic Union: A hybrid half-economics and half-political “Janus Bifrons”

Directory of Open Access Journals (Sweden)

Bruno S. Sergi

2018-01-01

Full Text Available The Eurasian Economic Union is an institution formalized in January 2015 for the purpose of regional economic integration; it includes five countries: Russia, Kazakhstan, Belarus, Armenia, and Kyrgyzstan, and may include Mongolia and Tajikistan in the future. With a GDP of $1.59 trillion in 2015, an industrial production of $1.3 trillion in 2014, and population of almost 200 million as of 2016, the EEAU could represent a geopolitical success that supports both Putin's ambitious political agenda and the Union's economic prospects. Although the efforts of this Union are ongoing and long-term success is not certain, the Russia-led Eurasian Economic Union can be considered a hybrid half-economics and half-political “Janus Bifrons” that serves as a powerful illustration of what Putin envisions for the post-Soviet space. Despite promising steps so far, more should be done toward the achievement of economic development and balanced opportunity for all Eurasian countries. Russia's longstanding role within the Union, as well as its power and political motivations, are all considerations that must be accounted for.

Transmission Electron Microscopy of the Gastrointestinal Tract of Nile Perch Lates niloticus

OpenAIRE

Namulawa, V. T; Kato, C. D; Nyatia, E; Rutaisire, J; Britz, P. J

2015-01-01

The ultrastructure of the gastrointestinal tract of Nile perch was described using Transmission Electron Microscopy standard procedures. Investigations revealed the presence of mucous cells, blood vessels and oil droplets plus several nerve cells and muscle bundles in the oral cavity. Further observations revealed columnar epithelial cells in the oesophagus, with a ragged surface, high electron dense cytoplasm, intercellular spaces, mitochondria and mucus granules. The lamina propria of the o...

Design of nest access grids and perches in front of the nests: Influence on the behavior of laying hens.

Science.gov (United States)

Stämpfli, K; Buchwalder, T; Fröhlich, E K F; Roth, B A

2013-04-01

In aviary systems for laying hens, it is important to provide suitable nest access platforms in front of the nests, allowing hens to reach and explore each of the nests easily. This access platform is needed to achieve good nest acceptance by the hens and thereby prevent mislaid eggs. In the present experiment, the behavior of hens using 2 different nest access platforms, a plastic grid and 2 wooden perches, was examined. Furthermore, the nests were placed on both sides of the aviary rack (corridor side and outdoor side), either integrated into the aviary rack itself (integrated nest; IN) or placed on the walls of the pens (wall nest; WN), resulting in a 2 × 2 factorial design Four thousand five hundred white laying hens were housed in 20 test pens. The eggs in the nests and mislaid eggs were collected daily, and the behavior of hens on the nest accesses was filmed during wk 25 and 26, using focal observation and scan sampling methods. More balancing, body contact, and agonistic interactions were expected for nests with perches, whereas more walking and nest inspections were expected for nests with grids. There were more mislaid eggs and balancing found in pens equipped with nests with wooden perches. More agonistic interactions and balancing, less standing, and a longer duration of nest inspection were found with the WN compared with the IN. Interactions between platform design and position of the nests were found for duration of nest visits, body contact, and walking, with the highest amount for WN equipped with plastic grids. Nests on the corridor side were favored by the hens. Nest-related behaviors, such as nest inspection, standing, and walking, decreased over time as did the number of hens on the nest accesses, whereas sitting increased. These results indicate that the hens had more difficulties in gripping the perches as designed. The lower number of hens on the nest access platforms in front of IN may be due to a better distribution around nests and tier

Ancestry and demography and descendants of Iron Age nomads of the Eurasian Steppe

Science.gov (United States)

Unterländer, Martina; Palstra, Friso; Lazaridis, Iosif; Pilipenko, Aleksandr; Hofmanová, Zuzana; Groß, Melanie; Sell, Christian; Blöcher, Jens; Kirsanow, Karola; Rohland, Nadin; Rieger, Benjamin; Kaiser, Elke; Schier, Wolfram; Pozdniakov, Dimitri; Khokhlov, Aleksandr; Georges, Myriam; Wilde, Sandra; Powell, Adam; Heyer, Evelyne; Currat, Mathias; Reich, David; Samashev, Zainolla; Parzinger, Hermann; Molodin, Vyacheslav I.; Burger, Joachim

2017-03-01

During the 1st millennium before the Common Era (BCE), nomadic tribes associated with the Iron Age Scythian culture spread over the Eurasian Steppe, covering a territory of more than 3,500 km in breadth. To understand the demographic processes behind the spread of the Scythian culture, we analysed genomic data from eight individuals and a mitochondrial dataset of 96 individuals originating in eastern and western parts of the Eurasian Steppe. Genomic inference reveals that Scythians in the east and the west of the steppe zone can best be described as a mixture of Yamnaya-related ancestry and an East Asian component. Demographic modelling suggests independent origins for eastern and western groups with ongoing gene-flow between them, plausibly explaining the striking uniformity of their material culture. We also find evidence that significant gene-flow from east to west Eurasia must have occurred early during the Iron Age.

Metabolic and thyroidal response in air-breathing perch (Anabus testudineus) to water-borne kerosene

NARCIS (Netherlands)

Peter, V.S.; Joshua, E.K.; Wendelaar Bonga, S.E.; Peter, M.C.S.

2007-01-01

To address the physiological compensatory adaptations in air-breathing fish to a toxicant, we studied the metabolite pattern, serum and liver enzymes and thyroidal response in a tropical air-breathing perch, Anabas testudineus (kept at 30 _C in a 12-h L:D cycle) after exposing the fish for 48 h to

Molecular identification of a yellow perch viral disease associated with exposure to oil sands process affected waters

International Nuclear Information System (INIS)

Hogan, N.; Van den Heuvel, M.; Phalen, L.

2010-01-01

Large volumes of tailings and process affected water are generated as a result of oil sand mining processes. This presentation discussed the safe incorporation of these wastes into the terrestrial and aquatic landscape. A study was conducted in which yellow perch were stocked into experimental ponds, namely Demonstration Pond and South Bison Pond, during the periods of 1995-1997 and 2008-2010. Demonstration Pond was comprised of mature fine tailings capped with natural surface water, while South Bison Pond was formed at a site surrounded by overburden or lean oil sands. Disease surveys were conducted at these experimental ponds and also at Mildred, Sucker, and Kimowin Lakes. External white nodular lesions, characteristic of lymphocystis disease were observed on perch at all sites except Kimowin Lake. The identity of the virus was confirmed by DNA extraction and PCR with genotype generic major capsid protein gene primers. The presence of lymphocystis disease virus in perch was confirmed through sequencing of PCR results. The viral genotype appeared to be different from any previously isolated viral genotype. During the course of the study, there was an increasing incidence of the disease at Demonstration Pond and a decreasing incidence at the South Bison Pond. The intensity of the disease was found to be proportional to the incidence, which was positively correlated with changes in naphthenic acid concentration.

Seasonal prediction and predictability of Eurasian spring snow water equivalent in NCEP Climate Forecast System version 2 reforecasts

Science.gov (United States)

He, Qiong; Zuo, Zhiyan; Zhang, Renhe; Zhang, Ruonan

2018-01-01

The spring snow water equivalent (SWE) over Eurasia plays an important role in East Asian and Indian monsoon rainfall. This study evaluates the seasonal prediction capability of NCEP Climate Forecast System version 2 (CFSv2) retrospective forecasts (1983-2010) for the Eurasian spring SWE. The results demonstrate that CFSv2 is able to represent the climatological distribution of the observed Eurasian spring SWE with a lead time of 1-3 months, with the maximum SWE occurring over western Siberia and Northeastern Europe. For a longer lead time, the SWE is exaggerated in CFSv2 because the start of snow ablation in CFSv2 lags behind that of the observation, and the simulated snowmelt rate is less than that in the observation. Generally, CFSv2 can simulate the interannual variations of the Eurasian spring SWE 1-5 months ahead of time but with an exaggerated magnitude. Additionally, the downtrend in CFSv2 is also overestimated. Because the initial conditions (ICs) are related to the corresponding simulation results significantly, the robust interannual variability and the downtrend in the ICs are most likely the causes for these biases. Moreover, CFSv2 exhibits a high potential predictability for the Eurasian spring SWE, especially the spring SWE over Siberia, with a lead time of 1-5 months. For forecasts with lead times longer than 5 months, the model predictability gradually decreases mainly due to the rapid decrease in the model signal.

Perspectives on long-term Eurasian energy supply: the role of the energy charter

International Nuclear Information System (INIS)

Kemper, R.

2004-01-01

This paper examines Croatian energy outlook in the broader 'Eurasian' context, taking into consideration the prospect of increasing energy import dependency in Western and Central Europe, and assesses the contribution that multilateral instruments, such as the Energy Charter Treaty, can make in promoting security of supply.(author)

Nourishment of perched sand dunes and the issue of erosion control in the Great Lakes

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Marsh, William M.

1990-09-01

Although limited in coverage, perched sand dunes situated on high coastal bluffs are considered the most prized of Great Lakes dunes. Grand Sable Dunes on Lake Superior and Sleeping Bear Dunes on Lake Michigan are featured attractions of national lakeshores under National Park Service management. The source of sand for perched dunes is the high bluff along their lakeward edge. As onshore wind crosses the bluff, flow is accelerated upslope, resulting in greatly elevated levels of wind stress over the slope brow. On barren, sandy bluffs, wind erosion is concentrated in the brow zone, and for the Grand Sable Bluff, it averaged 1 m3/yr per linear meter along the highest sections for the period 1973 1983. This mechanism accounts for about 6,500 m3 of sand nourishment to the dunefield annually and clearly has been the predominant mechanism for the long-term development of the dunefield. However, wind erosion and dune nourishment are possible only where the bluff is denuded of plant cover by mass movements and related processes induced by wave erosion. In the Great Lakes, wave erosion and bluff retreat vary with lake levels; the nourishment of perched dunes is favored by high levels. Lake levels have been relatively high for the past 50 years, and shore erosion has become a major environmental issue leading property owners and politicians to support lake-level regulation. Trimming high water levels could reduce geomorphic activity on high bluffs and affect dune nourishment rates. Locally, nourishment also may be influenced by sediment accumulation associated with harbor protection facilities and by planting programs aimed at stabilizing dunes.

Prolonged air-breathing and recovery modify the thyroid and interrenal axes in climbing perch (Anabas testudineus)

NARCIS (Netherlands)

Peter, M.C.S.; Wendelaar Bonga, S.E.

2007-01-01

To examine the response of thyroid and intrenal axes to hydromineral and metabolic responses in air-breathing fish during their territorial migration, we quantified several physiological markers in the tropical obligate air-breathing perch (Anabas testudineus) during air breathing on land and in

Match or mismatch: the influence of phenology on size-dependent life history and divergence in population structure

Science.gov (United States)

Borcherding, Jost; Beeck, Peter; DeAngelis, Donald L.; Scharf, Werner R.

2010-01-01

Summary 1. In gape-limited predators, body size asymmetries determine the outcome of predator-prey interactions. Due to ontogenetic changes in body size, the intensity of intra- and interspecific interactions may change rapidly between the match situation of a predator-prey system and the mismatch situation in which competition, including competition with the prey, dominates. 2. Based on a physiologically structured population model using the European perch (Perca fluviatilis), analysis was performed on how prey density (bream, Abramis brama), initial size differences in the young-of-the-year (YOY) age cohort of the predator, and phenology (time-gap in hatching of predator and prey) influence the size structure of the predator cohort. 3. In relation to the seasonality of reproduction, the match situation of the predator-prey system occurred when perch hatched earlier than bream and when no gape-size limitations existed, leading to decreased size divergence in the predator age cohort. Decreased size divergence was also found when bream hatched much earlier than perch, preventing perch predation on bream occurring, which, in turn, increased the competitive interaction of the perch with bream for the common prey, zooplankton; i.e. the mismatch situation in which also the mean size of the age cohort of the predator decreased. 4. In between the total match and the mismatch, however, only the largest individuals of the perch age cohort were able to prey on the bream, while smaller conspecifics got trapped in competition with each other and with bream for zooplankton, leading to enlarged differences in growth that increased size divergence. 5. The modelling results were combined with 7 years of field data in a lake, where large differences in the length-frequency distribution of YOY perch were observed after their first summer. These field data corroborate that phenology and prey density per predator are important mechanisms in determining size differences within the YOY

Inferring processes from spatial patterns: the role of directional and non-directional forces in shaping fish larvae distribution in a freshwater lake system.

Directory of Open Access Journals (Sweden)

Andrea Bertolo

Full Text Available Larval dispersal is a crucial factor for fish recruitment. For fishes with relatively small-bodied larvae, drift has the potential to play a more important role than active habitat selection in determining larval dispersal; therefore, we expect small-bodied fish larvae to be poorly associated with habitat characteristics. To test this hypothesis, we used as model yellow perch (Perca flavescens, whose larvae are among the smallest among freshwater temperate fishes. Thus, we analysed the habitat association of yellow perch larvae at multiple spatial scales in a large shallow fluvial lake by explicitly modelling directional (e.g. due to water currents and non-directional (e.g. due to aggregation spatial patterns. This allowed us to indirectly assess the relative roles of drift (directional process and potential habitat choice on larval dispersal. Our results give weak support to the drift hypothesis, whereas yellow perch show a strong habitat association at unexpectedly small sizes, when compared to other systems. We found consistent non-directional patterns in larvae distributions at both broad and medium spatial scales but only few significant directional components. The environmental variables alone (e.g. vegetation generally explained a significant and biologically relevant fraction of the variation in fish larvae distribution data. These results suggest that (i drift plays a minor role in this shallow system, (ii larvae display spatial patterns that only partially covary with environmental variables, and (iii larvae are associated to specific habitats. By suggesting that habitat association potentially includes an active choice component for yellow perch larvae, our results shed new light on the ecology of freshwater fish larvae and should help in building more realistic recruitment models.

Application of HEC-RAS for flood forecasting in perched river-A case study of hilly region, China

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Sun, Pingping; Wang, Shuqian; Gan, Hong; Liu, Bin; Jia, Ling

2017-04-01

Flooding in small and medium rivers are seriously threatening the safety of human beings’ life and property. The simulation forecasting of the river flood and bank risk in hilly region has gradually become a hotspot. At present, there are few studies on the simulation of hilly perched river, especially in the case of lacking section flow data. And the method of how to determine the position of the levee breach along the river bank is not much enough. Based on the characteristics of the sections in hilly perched river, an attempt is applied in this paper which establishes the correlation between the flow profile computed by HEC-RAS model and the river bank. A hilly perched river in Lingshi County, Shanxi Province of China, is taken as the study object, the levee breach positions along the bank are simulated under four different design storm. The results show that the flood control standard of upper reach is high, which can withstand the design storm of 100 years. The current standard of lower reach is low, which is the flooding channel with high frequency. As the standard of current channel between the 2rd and the 11th section is low, levee along that channel of the river bank is considered to be heighten and reinforced. The study results can provide some technical support for flood proofing in hilly region and some reference for the reinforcement of river bank.

Eurasian polities as hybrid regimes: The case of Putin's Russia

Directory of Open Access Journals (Sweden)

Henry E. Hale

2010-01-01

Full Text Available Most Eurasian countries' political systems are not accurately described as some version of either democracy or authoritarianism. Nor does it advance social science to study each of these countries' political systems as being completely unique, sharing no significant commonalities with those of other countries. Instead, it is more fruitful to understand many Eurasian countries as a type of hybrid regime, a system that combines important elements of both democracy and autocracy in some way. One of the most important features of Eurasia's hybrid regimes, one that is shared by many hybrid regimes worldwide, is that they combine contested elections with pervasive political clientelism. Political developments in these countries can thus be usefully understood as machine politics, and the development of political systems can be understood as processes of rearranging the components of the machines in different ways. The usefulness of this approach is demonstrated through an in-depth study of the Russian Federation. It is argued that Russian political development under Putin is best understood not as “authoritarianization” but as a process in which Russia transitioned from a system of “competing pyramids” of machine power to a “single-pyramid” system, a system dominated by one large political machine. It turns out that in single-pyramid systems that preserve contested elections, as does Russia, public opinion matters more than in typical authoritarian regimes.

Ancient mitochondrial DNA and the genetic history of Eurasian beaver (Castor fiber) in Europe.

Science.gov (United States)

Horn, Susanne; Prost, Stefan; Stiller, Mathias; Makowiecki, Daniel; Kuznetsova, Tatiana; Benecke, Norbert; Pucher, Erich; Hufthammer, Anne K; Schouwenburg, Charles; Shapiro, Beth; Hofreiter, Michael

2014-04-01

After centuries of human hunting, the Eurasian beaver Castor fiber had disappeared from most of its original range by the end of the 19th century. The surviving relict populations are characterized by both low genetic diversity and strong phylogeographical structure. However, it remains unclear whether these attributes are the result of a human-induced, late Holocene bottleneck or already existed prior to this reduction in range. To investigate genetic diversity in Eurasian beaver populations during the Holocene, we obtained mitochondrial control region DNA sequences from 48 ancient beaver samples and added 152 modern sequences from GenBank. Phylogeographical analyses of the data indicate a differentiation of European beaver populations into three mitochondrial clades. The two main clades occur in western and eastern Europe, respectively, with an early Holocene contact zone in eastern Europe near a present-day contact zone. A divergent and previously unknown clade of beavers from the Danube Basin survived until at least 6000 years ago, but went extinct during the transition to modern times. Finally, we identify a recent decline in effective population size of Eurasian beavers, with a stronger bottleneck signal in the western than in the eastern clade. Our results suggest that the low genetic diversity and the strong phylogeographical structure in recent beavers are artefacts of human hunting-associated population reductions. While beaver populations have been growing rapidly since the late 19th century, genetic diversity within modern beaver populations remains considerably reduced compared to what was present prior to the period of human hunting and habitat reduction.

Welfare of organic laying hens kept at different indoor stocking densities in a multi-tier aviary system. II: live weight, health measures and perching.

Science.gov (United States)

Steenfeldt, S; Nielsen, B L

2015-09-01

Multi-tier aviary systems, where conveyor belts below the tiers remove the manure at regular intervals, are becoming more common in organic egg production. The area on the tiers can be included in the net area available to the hens (also referred to as usable area) when calculating maximum indoor stocking densities in organic systems within the EU. In this article, results on live weight, health measures and perching are reported for organic laying hens housed in a multi-tier system with permanent access to a veranda and kept at stocking densities (D) of 6, 9 and 12 hens/m2 available floor area, with concomitant increases in the number of hens per trough, drinker, perch and nest space. In a fourth treatment, access to the top tier was blocked reducing vertical, trough, and perch access at the lowest stocking density (D6x). In all other aspects than stocking density, the experiment followed the EU regulations on the keeping of organic laying hens. Hen live weight, mortality and foot health were not affected by the stocking densities used in the present study. Other variables (plumage condition, presence of breast redness and blisters, pecked tail feathers, and perch use) were indirectly affected by the increase in stocking density through the simultaneous reduction in access to other resources, mainly perches and troughs. The welfare of the hens was mostly affected by these associated constraints, despite all of them being within the allowed minimum requirements for organic production in the EU. Although the welfare consequences reported here were assessed to be moderate to minor, it is important to take into account concurrent constraints on access to other resources when higher stocking densities are used in organic production.

Transregionalism: Underlying Concept of EAEU-ASEAN Cooperation and Greater Eurasian Partnership

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Anna A. Garmash

2017-01-01

Full Text Available Nowadays the EAEU seeks to integrate itself into the global economy as one of its regional economic centers. Developing ties with other regional integration groups corresponds the EAEU’s interests and facilitates the polycentric structure of the emerging world order. In this respect, in 2016 on the sidelines of the third Russia-ASEAN Summit Russian President Vladimir Putin proposed to develop stronger relations between the EAEU and ASEAN as well as to form a greater Eurasian partnership encompassing the EAEU, the SCO and ASEAN. While geographically vast, these projects lack conceptual underpinning. It is deemed that transregionalism – an international phenomenon which is insuffi ciently explored by both Western and Russian scholars, can provide a crucial theoretical foundation for these initiatives. The author compares the mechanisms which ASEAN employs to promote transregional cooperation with the EU, MERCOSUR and the GCC as well as within the frameworks of such dialogue platforms as ASEM and FEALAC. The author suggests that EAEU-ASEAN relations should be analyzed from the viewpoint of a classic transregionalism, while a greater Eurasian partnership seen as an example of a broader one. The results of the analysis are instrumental in laying out practical recommendations for the EAEU in carrying out its transregional agenda.

Fish mercury levels in lakes - adjusting for Hg and fish-size covariation

International Nuclear Information System (INIS)

Sonesten, Lars

2003-01-01

Fish-size covariation can be circumvented by regression intercepts of Hg vs. fish length as lake-specific Hg levels. - Accurate estimates of lake-specific mercury levels are vital in assessing the environmental impact on the mercury content in fish. The intercepts of lake-specific regressions of Hg concentration in fish vs. fish length provide accurate estimates when there is a prominent Hg and fish-size covariation. Commonly used regression methods, such as analysis of covariance (ANCOVA) and various standardization techniques are less suitable, since they do not completely remove the fish-size covariation when regression slopes are not parallel. Partial least squares (PLS) regression analysis reveals that catchment area and water chemistry have the strongest influence on the Hg level in fish in circumneutral lakes. PLS is a multivariate projection method that allows biased linear regression analysis of multicollinear data. The method is applicable to statistical and visual exploration of large data sets, even if there are more variables than observations. Environmental descriptors have no significant impact on the slopes of linear regressions of the Hg concentration in perch (Perca fluviatilis L.) vs. fish length, suggesting that the slopes mainly reflect ontogenetic dietary shifts during the perch life span

Denisovan Ancestry in East Eurasian and Native American Populations.

Science.gov (United States)

Qin, Pengfei; Stoneking, Mark

2015-10-01

Although initial studies suggested that Denisovan ancestry was found only in modern human populations from island Southeast Asia and Oceania, more recent studies have suggested that Denisovan ancestry may be more widespread. However, the geographic extent of Denisovan ancestry has not been determined, and moreover the relationship between the Denisovan ancestry in Oceania and that elsewhere has not been studied. Here we analyze genome-wide single nucleotide polymorphism data from 2,493 individuals from 221 worldwide populations, and show that there is a widespread signal of a very low level of Denisovan ancestry across Eastern Eurasian and Native American (EE/NA) populations. We also verify a higher level of Denisovan ancestry in Oceania than that in EE/NA; the Denisovan ancestry in Oceania is correlated with the amount of New Guinea ancestry, but not the amount of Australian ancestry, indicating that recent gene flow from New Guinea likely accounts for signals of Denisovan ancestry across Oceania. However, Denisovan ancestry in EE/NA populations is equally correlated with their New Guinea or their Australian ancestry, suggesting a common source for the Denisovan ancestry in EE/NA and Oceanian populations. Our results suggest that Denisovan ancestry in EE/NA is derived either from common ancestry with, or gene flow from, the common ancestor of New Guineans and Australians, indicating a more complex history involving East Eurasians and Oceanians than previously suspected. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Fish as a bioindicator of heavy metals pollution in aquatic ecosystem of Pluszne Lake, Poland, and risk assessment for consumer's health.

Science.gov (United States)

Łuczyńska, Joanna; Paszczyk, Beata; Łuczyński, Marek J

2018-05-30

Heavy metals content (Zn, Cu and Hg) were measured in gills, liver, gonads and muscles of perch, Perca fluviatilis (L.) and roach, Rutilus rutilus (L.) from Lake Pluszne (north-eastern Poland). Correlations between heavy metals levels and total length, weight, HSI, GSI and FCF were examined. As expected, muscles contained the significantly highest values of Hg (P ≤ .05). The concentrations of Zn were significantly higher in gills of roach and gonads of perch (P ≤ .05), while the liver of fish accumulated significantly more Cu than other organs (P ≤ .05). In all organs of perch the higher content of mercury was found (P ≤ .05). The value of Zn and Cu was highest in organs of roach (P ≤ .05) (with the exception of Zn in muscles P > .05). Sequence of metals in both species was Zn > Cu > Hg. Only in muscle tissue, Hg was significantly positive correlated with weight of roach (r = 0.811, P = .045) and perch (r = 0.652, P = .041), and total length of roach (r = 0.806, P = .005). A positive relationship was also observed between Zn concentration in gills of perch and their weight (r = 0.634, P = .049). In contrary, Zn in gills of roach decreased with weight (r = -0.693, P = .026)) and length (r = -0.668, P = .035). Cu concentration in liver of perch was statistically positively correlated with HSI (r = 0.717, P = .020), whereas Hg content in muscle tissue of roach with FCF (r = 0.643, P = .045). There was negative relationship between Hg in perch gonads and GSI (r = -0.808, P = .005). Metal pollution index (MPI) in gills, liver, gonads and muscles of roach was 7.68, 7.24, 6.77 and 3.13, respectively, whereas in these organs of perch was 3.25 (gills), 4.75 (liver), 5.84 (gonads) and 4.44 (muscles), therefore the contamination of each tissue ranged from very low contamination to low contamination. The concentration of mercury was lower than the maximum acceptable limit estimated by the Commission Regulation (EC) No 629/2008 of 2 July 2008. The values of HI and THQ

Bioaccumulation of organochlorine pollutants in the fish community in Lake Arungen, Norway

International Nuclear Information System (INIS)

Sharma, Chhatra Mani; Rosseland, Bjorn Olav; Almvik, Marit; Eklo, Ole Martin

2009-01-01

Organochlorine pollutants in the major fish species (pike Esox lucius, perch Perca fluviatilis, and roach Rutilus rutilus) of Lake Arungen, Norway, were investigated after an extensive removal of large pike in 2004. The organochlorine pollutants detected in fish liver samples in 2005 were dichlorodiphenyltrichloroethane (DDTs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and heptachlor epoxide (HCE). DDTs were the dominant among all analyzed OCs. ΣPCB and HCB, detected in fish from two clearly distinct trophic levels (prey and predators), give an indication of biomagnification. All OC concentrations in female pike were significantly lower compared to males, which might be due to the removal of high concentrations of pollutants in roe during spawning. - Organochlorine pollutants in fish tissues tend to magnify up the food chain

Exposure-related effects of Pseudomonas fluorescens, strain CL145A, on coldwater, coolwater, and warmwater fish

Science.gov (United States)

Luoma, James A.; Weber, Kerry L.; Denise A. Mayer,

2015-01-01

The exposure-related effects of a commercially prepared spray-dried powder (SDP) formulation of Pseudomonas fluorescens, strain CL145A, were evaluated on coldwater, coolwater, and warmwater fish endemic to the Great Lakes and Upper Mississippi River Basins. Nine species of young-of-the-year fish were exposed to SDP for 24 hours by using continuous-flow, serial-dilution exposure systems at temperatures of 12 degrees Celsius (°C; 2 species; Oncorhynchus mykiss [rainbow trout] and Salvelinus fontinalis [brook trout]), 17 °C (3 species; Perca flavescens [yellow perch], Sander vitreus [walleye], and Acipenser fulvescens [lake sturgeon]), or 22 °C (4 species; Micropterus salmoides [largemouth bass], Micropterus dolomieu [smallmouth bass], Lepomis macrochirus [bluegill sunfish], and Ictalurus punctatus [channel catfish]).

Assessing the efficacy of corn-based bait containing antimycin-a to control common carp populations using laboratory and pond experiments

Science.gov (United States)

Poole, Joshua R.; Sauey, Blake W.; Amberg, Jon J.; Bajer, Przemyslaw G.

2018-01-01

Strategic use of oral toxicants could allow for practical and sustainable control schemes for the invasive common carp (Cyprinus carpio, or ‘carp’) if a toxicant selectively targeted carp and not native species. In this study, we incorporated antimycin-a (ANT-A), a known fish toxicant, into a corn-based bait and conducted a series of experiments to determine its toxicity, leaching rate, and species-specificity. Our results showed that ANT-A was lethal to carp at doses ≥ 4 mg/kg and that the amount of ANT-A that leached out of the bait in 72 h was not lethal to carp or bluegill (Lepomis macrochirus). Species-specificity trials were conducted in 227 L tanks, in which carp were stocked with three native species representing families that occur sympatrically with carp in our study region: the fathead minnow (Pimephales promelas), yellow perch (Perca flavescens) and bluegill. These trials showed high mortality of carp (46%) and fathead minnows (76%) but no significant mortality of perch or bluegill. Finally, a pond study, which used the same species composition except for fathead minnows, resulted in 37% morality among adult carp and no mortality among perch or bluegill. Our results suggest that corn-based bait that contains ANT-A could be used to selectively control carp in ecosystems dominated by percids or centrarchids, such as lakes across the Great Plains ecoregion of North America, where carp are especially problematic.

Selective exploitation of large pike Esox lucius-Effects on mercury concentrations in fish populations

International Nuclear Information System (INIS)

Sharma, Chhatra Mani; Borgstrom, Reidar; Huitfeldt, Jorgen Sinkaberg; Rosseland, Bjorn Olav

2008-01-01

The present study outlines two main trends of mercury transfer patterns through the fish community: 1) the Hg concentrations increase with increase in the trophic level, with top predators having the highest concentrations, and 2) a fast growth rate may dilute the concentrations of Hg in fish muscle tissue (growth biodilution). In 2004, an extensive reduction in number of large pike (Esox lucius L.), was initiated by selective gillnet fishing in Lake Arungen, Norway, in order to increase the pike recruitment due to an expected reduction in cannibalism. In this connection, total mercury (THg) concentrations in the fish community were studied both before (2003) and after (2005) the removal of large pike. The δ 15 N signatures and stomach content analyses indicated that pike and perch (Perca fluviatilis L.) occupied the highest trophic position, while roach (Rutilus rutilus (L.)) was at the lower level, and rudd (Scardinius erythrophthalmus L.) at the lowest. The piscivores, pike and perch, had the highest concentrations of THg. The biomagnification rate of THg through the food web in the fish community was 0.163 ( per milleδ 15 N), with the highest uptake rate (0.232) in perch. A significant decrease in THg concentrations was found in all fish species in 2005 compared to 2003. Removal of the top predators in an Hg contaminated lake might thus be an important management tool for reducing Hg levels in fish, thereby reducing health risk to humans

Challenges of Eurasian integration after the Ukrainian Crisis

Directory of Open Access Journals (Sweden)

A. Skriba

2014-05-01

Full Text Available The regional situation in Eastern Europe changed significantly by the end of the first decade of the 21st century. Competitionbetween Russia and the European Union increased during the 2000s, while at the same time both actors were changing their approach to the six states of the former USSR that lie between Russia and the EU – Azerbaijan, Armenia, Belarus, Georgia, Moldova and Ukraine. In order to widen and deepen their influence on those territories and to reduce uncertainty about their regional politics, Moscow and Brussels developed their own integration projects and demanded those post-Soviet states define their position in the EU-Russia competition. Russian and European scholars, when trying to analyze the future of the Post-Soviet Six states, mostly examine the attractiveness of the two integration projects. While important, such an approach is insufficient, as it ignores the individual internal environments. To assess the prospects for Russia’s Eurasian Economic Union and the EU’s Eastern Partnership, however, one must look inside the six states, which are so important for both Moscow and Brussels. This article explores the aspects of the European and Eurasian integration projects that may be attractive to the six states. Within this framework, it considers what and how elements of those states’ internal environment might influence their choice by examining and comparing both integration projects. It proposes focusing directly on the countries that are currently facing the dilemma of integration and are expected to choose. Despite a number of internal factors influencing the states’ integration behaviour, research has shown that in such circumstances, a choice (whether it is made cannot be considered final, given the individual internal environments of the Six. Their further integration will require additional mechanisms of stimulation, which will need to be developed by the centres of integration — namely, Moscow and

PAN EURASIAN EXPERIMENT (PEEX - A RESEARCH INITIATIVE MEETING THE GRAND CHALLENGES OF THE CHANGING ENVIRONMENT OF THE NORTHERN PAN-EURASIAN ARCTIC-BOREAL AREAS

Directory of Open Access Journals (Sweden)

Hanna K. Lappalainen

2014-01-01

Full Text Available The Pan-Eurasian Experiment (PEEX is a new multidisciplinary, global change research initiative focusing on understanding biosphere-ocean-cryosphere-climate interactions and feedbacks in Arctic and boreal regions in the Northern Eurasian geographical domain. PEEX operates in an integrative way and it aims at solving the major scientific and society relevant questions in many scales using tools from natural and social sciences and economics. The research agenda identifies the most urgent large scale research questions and topics of the land-atmosphere-aquatic-anthropogenic systems and interactions and feedbacks between the systems for the next decades. Furthermore PEEX actively develops and designs a coordinated and coherent ground station network from Europe via Siberia to China and the coastal line of the Arctic Ocean together with a PEEX-modeling platform. PEEX launches a program for educating the next generation of multidisciplinary researcher and technical experts. This expedites the utilization of the new scientific knowledge for producing a more reliable climate change scenarios in regional and global scales, and enables mitigation and adaptation planning of the Northern societies. PEEX gathers together leading European, Russian and Chinese research groups. With a bottom-up approach, over 40 institutes and universities have contributed the PEEX Science Plan from 18 countries. In 2014 the PEEX community prepared Science Plan and initiated conceptual design of the PEEX land-atmosphere observation network and modeling platform. Here we present the PEEX approach as a whole with the specific attention to research agenda and preliminary design of the PEEX research infrastructure.

Assessment of the public health in the course of the Eurasian Economic Community programme 'Reclamation of areas of the Eurasian Economic Community member-states affected by the uranium mines'

International Nuclear Information System (INIS)

Kiselev, M.F.; Tukov, A.R.; Metlyaev, E.G.; Seregin, V.A.

2012-01-01

Full text: The inter-state target programme of the Eurasian Economic Community 'Reclamation of areas of the Eurasian Economic Community member-states affected by the uranium mines' includes assessment of impact of these facilities on the public health at the adjacent areas and estimation of potential risk of radiation induced diseases. This work will be carried out as follows: collection of indicators of the State medical statistic reporting by areas of natural uranium mining and milling waste storage to be reclaimed; data input to the database, data verification, calculation of relative indexes and estimation of potential risk of radiation induced diseases; comparative analysis of the public health at inspected and reference areas, estimation of potential risk of radiation induced diseases; development of recommendations on enhancing medical service of the population. Burnasyan Federal Medical Biophysical Centre developed the method of data collection in order to assess and to perform the comparative analysis of the public health. At the early stage of the programme, for the purpose of the comparative analysis of the public health at the contaminated areas, we are going to identify areas affected by uranium plants and some reference areas with approximately same quality of health-care service. When collecting medical data of the public, the special attention will be paid to malignant neoplasm incidence, including trachea, bronchus, lung cancer and psycho-somatic diseases (hypertension, coronary heart disease, peptic ulcer and duodenal ulcers, and others). This kind of data will be collected as the number of registered patients by sex and age groups in the report of the state medical statistics 'Information on malignant neoplasm incidence over 1990 - 2014' (according to the reporting form 'Information on the number of diseases registered at the area under the clinic service'). The statistical bodies of the Eurasian Economic Community member-states will organize the

An update of hydrologic conditions and distribution of selected constituents in water, eastern Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2012-15

Science.gov (United States)

Bartholomay, Roy C.; Maimer, Neil V.; Rattray, Gordon W.; Fisher, Jason C.

2017-04-10

Since 1952, wastewater discharged to in ltration ponds (also called percolation ponds) and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain (ESRP) aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, maintains groundwater-monitoring networks at the INL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from the ESRP aquifer, multilevel monitoring system (MLMS) wells in the ESRP aquifer, and perched groundwater wells in the USGS groundwater monitoring networks during 2012-15.

How will climate change affect the potential distribution of Eurasian Tree Sparrows Passer montanus in North America?

Science.gov (United States)

Graham, Jim; Jarnevich, Catherine; Young, Nick; Newman, Greg; Stohlgren, Thomas

2011-01-01

Habitat suitability models have been used to predict the present and future potential distribution of a variety of species. Eurasian tree sparrows Passer montanus, native to Eurasia, have established populations in other parts of the world. In North America, their current distribution is limited to a relatively small region around its original introduction to St. Louis, Missouri. We combined data from the Global Biodiversity Information Facility with current and future climate data to create habitat suitability models using Maxent for this species. Under projected climate change scenarios, our models show that the distribution and range of the Eurasian tree sparrow could increase as far as the Pacific Northwest and Newfoundland. This is potentially important information for prioritizing the management and control of this non-native species.

Conceptual Layout of Wing Structure Using Topology Optimization for Morphing Micro Air Vehicles in a Perching Maneuver

Science.gov (United States)

2012-03-22

back out both to quickly ascend and to collect momentum -reducing drag. A few points along the perching trajectory will be extracted which are...derivation follows classical Kirchhoff plate theory (2D extension of Euler- Bernoulli beam theory). When minimizing a structure’s compli- ance, which is

Is Eurasian October snow cover extent increasing?

International Nuclear Information System (INIS)

Brown, R D; Derksen, C

2013-01-01

A number of recent studies present evidence of an increasing trend in Eurasian snow cover extent (SCE) in the October snow onset period based on analysis of the National Oceanic and Atmospheric Administration (NOAA) historical satellite record. These increases are inconsistent with fall season surface temperature warming trends across the region. Using four independent snow cover data sources (surface observations, two reanalyses, satellite passive microwave retrievals) we show that the increasing SCE is attributable to an internal trend in the NOAA CDR dataset to chart relatively more October snow cover extent over the dataset overlap period (1982–2005). Adjusting the series for this shift results in closer agreement with other independent datasets, stronger correlation with continentally-averaged air temperature anomalies, and a decrease in SCE over 1982–2011 consistent with surface air temperature warming trends over the same period. (letter)

Comparison of food habits of white perch (Morone americana) in the heated effluent canal of a steam electric station and in an adjacent river system

International Nuclear Information System (INIS)

Moore, C.J.; Fuller, S.L.H.; Burton, D.T.

1975-01-01

Analysis of the stomach contents of 97 white perch, Morone americana, taken from the effluent canal of a steam electric station (S.E.S.) and 106 white perch from adjacent Patuxent River waters indicated similar food habits from September 1970 through August 1971. However, 35 percent of all white perch taken from the heated effluent canal contained small pieces of coal and cinders, whereas only 3 percent of the river specimens contained such items in their stomachs. Fly ash and coal dust are present on the bottom of the S.E.S. canal, whereas little such material, if any, can be found on the river bottom in the study area. This suggests the canal fish were actively feeding in the heated effluent and not simply moving into the canal after feeding in the river. No significant difference (P greater than 0.05) was found between the average wet weight stomach contents of the river and canal fish within the same month

Hydrogeological and geochemical studies in the Perch Lake basin

International Nuclear Information System (INIS)

Barry, P.J.

1979-08-01

The Perch Lake basin is a small drainage system along the Ottawa River about 200 km west of Ottawa on the Canadian Shield. Since 1975, groups of scientists from several Canadian universities and government departments have been studying the hydrological, geological and geochemical properties of the basin. The object of these studies is to develop and test simulation models used to describe the time-dependent mass flow rates of water and dissolved and suspended substances through the basin. To review progress, a symposium/workshop was held at Chalk Rier in 1978 April. This report contains 24 extended summaries of the material presented verbally at the workshop. Subject matters include atmospheric sources and sinks, mass flows through the surface and subsurface regimes in the drainage basins and interactions occurring in the lake. (author)

Musculoskeletal anatomy of the Eurasian lynx, Lynx lynx (Carnivora: Felidae) forelimb: Adaptations to capture large prey?

Science.gov (United States)

Viranta, Suvi; Lommi, Hanna; Holmala, Katja; Laakkonen, Juha

2016-06-01

Mammalian carnivores adhere to two different feeding strategies relative to their body masses. Large carnivores prey on animals that are the same size or larger than themselves, whereas small carnivores prey on smaller vertebrates and invertebrates. The Eurasian lynx (Lynx lynx) falls in between these two categories. Lynx descend from larger forms that were probably large prey specialists, but during the Pleistocene became predators of small prey. The modern Eurasian lynx may be an evolutionary reversal toward specializing in large prey again. We hypothesized that the musculoskeletal anatomy of lynx should show traits for catching large prey. To test our hypothesis, we dissected the forelimb muscles of six Eurasian lynx individuals and compared our findings to results published for other felids. We measured the bones and compared their dimensions to the published material. Our material displayed a well-developed pectoral girdle musculature with some uniquely extensive muscle attachments. The upper arm musculature resembled that of the pantherine felids and probably the extinct sabertooths, and also the muscles responsible for supination and pronation were similar to those in large cats. The muscles controlling the pollex were well-developed. However, skeletal indices were similar to those of small prey predators. Our findings show that lynx possess the topographic pattern of muscle origin and insertion like in large felids. J. Morphol. 277:753-765, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Foraging sites of Eurasian lynx Lynx lynx: relative importance of microhabitat and prey occurrence

Czech Academy of Sciences Publication Activity Database

Belotti, E.; Červený, J.; Šustr, Pavel; Kreisinger, Jakub; Gaibani, G.; Bufka, L.

2013-01-01

Roč. 19, č. 2 (2013), s. 188-201 ISSN 0909-6396 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:68081766 ; RVO:67179843 Keywords : Eurasian Lynx * microhabitat * red deer * roe deer * stalking cover * predation Subject RIV: EH - Ecology, Behaviour Impact factor: 1.071, year: 2013

Trophic transfer of naturally produced brominated aromatic compounds in a Baltic Sea food chain.

Science.gov (United States)

Dahlgren, Elin; Lindqvist, Dennis; Dahlgren, Henrik; Asplund, Lillemor; Lehtilä, Kari

2016-02-01

Brominated aromatic compounds (BACs) are widely distributed in the marine environment. Some of these compounds are highly toxic, such as certain hydroxylated polybrominated diphenyl ethers (OH-PBDEs). In addition to anthropogenic emissions through use of BACs as e.g. flame retardants, BACs are natural products formed by marine organisms such as algae, sponges, and cyanobacteria. Little is known of the transfer of BACs from natural producers and further up in the trophic food chain. In this study it was observed that total sum of methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and OH-PBDEs increased in concentration from the filamentous red alga Ceramium tenuicorne, via Gammarus sp. and three-spined stickleback (Gasterosteus aculeatus) to perch (Perca fluviatilis). The MeO-PBDEs, which were expected to bioaccumulate, increased in concentration accordingly up to perch, where the levels suddenly dropped dramatically. The opposite pattern was observed for OH-PBDEs, where the concentration exhibited a general trend of decline up the food web, but increased in perch, indicating metabolic demethylation of MeO-PBDEs. Debromination was also indicated to occur when progressing through the food chain resulting in high levels of tetra-brominated MeO-PBDE and OH-PBDE congeners in fish, while some penta- and hexa-brominated congeners were observed to be the dominant products in the alga. As it has been shown that OH-PBDEs are potent disruptors of oxidative phosphorylation and that mixtures of different congener may act synergistically in terms of this toxic mode of action, the high levels of OH-PBDEs detected in perch in this study warrants further investigation into potential effects of these compounds on Baltic wildlife, and monitoring of their levels. Copyright © 2015 Elsevier Ltd. All rights reserved.

Novel Eurasian Highly Pathogenic Influenza A H5 Viruses in Wild Birds, Washington, USA, 2014

Centers for Disease Control (CDC) Podcasts

2015-03-24

Sarah Gregory reads an abridged version of the article, Novel Eurasian Highly Pathogenic Influenza A H5 Viruses in Wild Birds, Washington, USA, 2014.  Created: 3/24/2015 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 4/13/2015.

Biomagnification of mercury and selenium in two lakes in southern Norway

Energy Technology Data Exchange (ETDEWEB)

Økelsrud, Asle, E-mail: asle.okelsrud@hit.no [Department of Environmental and Health Studies, University College of Southeast Norway, Hallvard Eikas Plass 1, 3800 Bø (Norway); Lydersen, Espen [Department of Environmental and Health Studies, University College of Southeast Norway, Hallvard Eikas Plass 1, 3800 Bø (Norway); Fjeld, Eirik [Norwegian Institute for Water Research, Gaustadalléen 21, 0349 Oslo (Norway)

2016-10-01

We have investigated bioaccumulation and trophic transfer of both mercury (Hg) and selenium (Se) in two lakes in southern Norway to reveal a suggested mitigating effect of Se on Hg biota accumulation. The study included analysis of total Se (Se), total Hg (Hg), and methyl-mercury (MeHg) in water, littoral and pelagic invertebrates and perch (Perca fluviatilis), together with stable isotope analysis (δ{sup 15}N and δ{sup 13}C) in biota. Mean dissolved Se ranged from 22 to 59 ng L{sup −1}, while Hg and MeHg in lake water ranged from 1 to 3 ng L{sup −1} and 0.01 to 0.06 ng L{sup −1}. Biota Se and Hg concentrations (dry weight) ranged from 0.41 mg Se kg{sup −1} and 0.06 mg Hg kg{sup −1} in primary littoral invertebrates and up to 2.9 mg Se kg{sup −1} and 3.6 mg Hg kg{sup −1} in perch. Both Hg and Se biomagnified in the food web, with a trophic magnification factor (TMF) of 4.64 for Hg and 1.29 for Se. The reported positive transfer of Se in the food web, despite the low measured dissolved Se, suggest that a major proportion of the Se in these lakes are both highly bioavailable and bioaccumulative. However, we did not find support for a Se-facilitated inhibition in the accumulation of Hg in perch, as Se and Hg concentrations in perch muscle correlated positively and Se did not explain any variations in Hg after we controlled for the effects of other important covariates. We postulate that this may be a result of insufficient concentrations of dissolved Se and subsequently in biota in our studied lakes for an efficient Hg sequestration up the food web. - Highlights: • Hg, Se and stable isotopes were investigated in biota in two Norwegian Boreal lakes • Both Hg and Se biomagnified in the food web, with a TMF of 4.64 and 1.29 respectively • Food carbon source, trophic level and age explained Se and Hg variations in perch • Perch muscle Se and Hg were positively correlated.

Biomagnification of mercury and selenium in two lakes in southern Norway

International Nuclear Information System (INIS)

Økelsrud, Asle; Lydersen, Espen; Fjeld, Eirik

2016-01-01

We have investigated bioaccumulation and trophic transfer of both mercury (Hg) and selenium (Se) in two lakes in southern Norway to reveal a suggested mitigating effect of Se on Hg biota accumulation. The study included analysis of total Se (Se), total Hg (Hg), and methyl-mercury (MeHg) in water, littoral and pelagic invertebrates and perch (Perca fluviatilis), together with stable isotope analysis (δ 15 N and δ 13 C) in biota. Mean dissolved Se ranged from 22 to 59 ng L −1 , while Hg and MeHg in lake water ranged from 1 to 3 ng L −1 and 0.01 to 0.06 ng L −1 . Biota Se and Hg concentrations (dry weight) ranged from 0.41 mg Se kg −1 and 0.06 mg Hg kg −1 in primary littoral invertebrates and up to 2.9 mg Se kg −1 and 3.6 mg Hg kg −1 in perch. Both Hg and Se biomagnified in the food web, with a trophic magnification factor (TMF) of 4.64 for Hg and 1.29 for Se. The reported positive transfer of Se in the food web, despite the low measured dissolved Se, suggest that a major proportion of the Se in these lakes are both highly bioavailable and bioaccumulative. However, we did not find support for a Se-facilitated inhibition in the accumulation of Hg in perch, as Se and Hg concentrations in perch muscle correlated positively and Se did not explain any variations in Hg after we controlled for the effects of other important covariates. We postulate that this may be a result of insufficient concentrations of dissolved Se and subsequently in biota in our studied lakes for an efficient Hg sequestration up the food web. - Highlights: • Hg, Se and stable isotopes were investigated in biota in two Norwegian Boreal lakes • Both Hg and Se biomagnified in the food web, with a TMF of 4.64 and 1.29 respectively • Food carbon source, trophic level and age explained Se and Hg variations in perch • Perch muscle Se and Hg were positively correlated

Timing, frequency and environmental conditions associated with mainstem-tributary movement by a lowland river fish, golden perch (Macquaria ambigua.

Directory of Open Access Journals (Sweden)

Wayne M Koster

Full Text Available Tributary and mainstem connections represent important links for the movement of fish and other biota throughout river networks. We investigated the timing, frequency and environmental conditions associated with movements by adult golden perch (Macquaria ambigua between the mainstem of the mid-Murray River and a tributary, the Goulburn River, in south-eastern Australia, using acoustic telemetry over four years (2007-2011. Fish were tagged and released in autumn 2007-2009 in the mid-Murray (n = 42 and lower Goulburn (n = 37 rivers within 3-6 km of the mid-Murray-lower Goulburn junction. 38% of tagged fish undertook mainstem-tributary movements, characterised mostly by temporary occupation followed by return of fish to the original capture river. Approximately 10% of tagged fish exhibited longer-term shifts between the mainstem and tributary. Movement of fish from the tributary into the mainstem occurred primarily during the spawning season and in some years coincided with the presence of golden perch eggs/larvae in drift samples in the mainstem. Many of the tributary-to-mainstem movements occurred during or soon after changes in flow. The movements of fish from the mainstem into the tributary were irregular and did not appear to be associated with spawning. The findings show that golden perch moved freely across the mainstem-tributary interface. This demonstrates the need to consider the spatial, behavioural and demographic interdependencies of aquatic fauna across geographic management units such as rivers.

Timing, frequency and environmental conditions associated with mainstem-tributary movement by a lowland river fish, golden perch (Macquaria ambigua).

Science.gov (United States)

Koster, Wayne M; Dawson, David R; O'Mahony, Damien J; Moloney, Paul D; Crook, David A

2014-01-01

Tributary and mainstem connections represent important links for the movement of fish and other biota throughout river networks. We investigated the timing, frequency and environmental conditions associated with movements by adult golden perch (Macquaria ambigua) between the mainstem of the mid-Murray River and a tributary, the Goulburn River, in south-eastern Australia, using acoustic telemetry over four years (2007-2011). Fish were tagged and released in autumn 2007-2009 in the mid-Murray (n = 42) and lower Goulburn (n = 37) rivers within 3-6 km of the mid-Murray-lower Goulburn junction. 38% of tagged fish undertook mainstem-tributary movements, characterised mostly by temporary occupation followed by return of fish to the original capture river. Approximately 10% of tagged fish exhibited longer-term shifts between the mainstem and tributary. Movement of fish from the tributary into the mainstem occurred primarily during the spawning season and in some years coincided with the presence of golden perch eggs/larvae in drift samples in the mainstem. Many of the tributary-to-mainstem movements occurred during or soon after changes in flow. The movements of fish from the mainstem into the tributary were irregular and did not appear to be associated with spawning. The findings show that golden perch moved freely across the mainstem-tributary interface. This demonstrates the need to consider the spatial, behavioural and demographic interdependencies of aquatic fauna across geographic management units such as rivers.

Timing, Frequency and Environmental Conditions Associated with Mainstem–Tributary Movement by a Lowland River Fish, Golden Perch (Macquaria ambigua)

Science.gov (United States)

Koster, Wayne M.; Dawson, David R.; O’Mahony, Damien J.; Moloney, Paul D.; Crook, David A.

2014-01-01

Tributary and mainstem connections represent important links for the movement of fish and other biota throughout river networks. We investigated the timing, frequency and environmental conditions associated with movements by adult golden perch (Macquaria ambigua) between the mainstem of the mid-Murray River and a tributary, the Goulburn River, in south-eastern Australia, using acoustic telemetry over four years (2007–2011). Fish were tagged and released in autumn 2007–2009 in the mid-Murray (n = 42) and lower Goulburn (n = 37) rivers within 3–6 km of the mid-Murray-lower Goulburn junction. 38% of tagged fish undertook mainstem–tributary movements, characterised mostly by temporary occupation followed by return of fish to the original capture river. Approximately 10% of tagged fish exhibited longer-term shifts between the mainstem and tributary. Movement of fish from the tributary into the mainstem occurred primarily during the spawning season and in some years coincided with the presence of golden perch eggs/larvae in drift samples in the mainstem. Many of the tributary-to-mainstem movements occurred during or soon after changes in flow. The movements of fish from the mainstem into the tributary were irregular and did not appear to be associated with spawning. The findings show that golden perch moved freely across the mainstem–tributary interface. This demonstrates the need to consider the spatial, behavioural and demographic interdependencies of aquatic fauna across geographic management units such as rivers. PMID:24788137

Impacts of Early Summer Eurasian Snow Cover Change on Atmospheric Circulation in Northern Mid-Latitudes

Science.gov (United States)

Nozawa, T.

2016-12-01

Recently, Japan Aerospace Exploration Agency (JAXA) has developed a new long-term snow cover extent (SCE) product using Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) data spanning from 1980's to date. This new product (JAXA/SCE) has higher spatial resolution and smaller commission error compared with traditional SCE dataset of National Oceanic and Atmospheric Administration (NOAA/SCE). Continuity of the algorithm is another strong point in JAXA/SCE. According to the new JAXA/SCE dataset, the Eurasian SCE has been significantly retreating since 1980's, especially in late spring and early summer. Here, we investigate impacts of early summer Eurasian snow cover change on atmospheric circulation in Northern mid-latitudes, especially over the East Asia, using the new JAXA/SCE dataset and a few reanalysis data. We will present analyzed results on relationships between early summer SCE anomaly over the Eurasia and changes in atmospheric circulations such as upper level zonal jets (changes in strength, positions, etc.) over the East Asia.

Remarkable link between projected uncertainties of Arctic sea-ice decline and winter Eurasian climate

Science.gov (United States)

Cheung, Hoffman H. N.; Keenlyside, Noel; Omrani, Nour-Eddine; Zhou, Wen

2018-01-01

We identify that the projected uncertainty of the pan-Arctic sea-ice concentration (SIC) is strongly coupled with the Eurasian circulation in the boreal winter (December-March; DJFM), based on a singular value decomposition (SVD) analysis of the forced response of 11 CMIP5 models. In the models showing a stronger sea-ice decline, the Polar cell becomes weaker and there is an anomalous increase in the sea level pressure (SLP) along 60°N, including the Urals-Siberia region and the Iceland low region. There is an accompanying weakening of both the midlatitude westerly winds and the Ferrell cell, where the SVD signals are also related to anomalous sea surface temperature warming in the midlatitude North Atlantic. In the Mediterranean region, the anomalous circulation response shows a decreasing SLP and increasing precipitation. The anomalous SLP responses over the Euro-Atlantic region project on to the negative North Atlantic Oscillation-like pattern. Altogether, pan-Arctic SIC decline could strongly impact the winter Eurasian climate, but we should be cautious about the causality of their linkage.

Proceedings of the third Eurasian conference on nuclear science and its application

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-10-15

The third Eurasian conference on nuclear science and its application was held on 5-8 October, 2004 in Tashkent, Uzbekistan. The specialists discussed various aspects of modern problems of particle physics, relativistic nuclear physics and physics of atomic nuclei, radiochemistry, radioisotope production, technology of radioisotopes and compounds, activations analysis applications, radionuclides, radioimmunoassays, application of radioisotopes in industry, medicine, biology and agriculture. More than 330 talks were presented in the meeting. (k.m.)

Proceedings of the third Eurasian conference on nuclear science and its application

International Nuclear Information System (INIS)

2004-10-01

The third Eurasian conference on nuclear science and its application was held on 5-8 October, 2004 in Tashkent, Uzbekistan. The specialists discussed various aspects of modern problems of particle physics, relativistic nuclear physics and physics of atomic nuclei, radiochemistry, radioisotope production, technology of radioisotopes and compounds, activations analysis applications, radionuclides, radioimmunoassays, application of radioisotopes in industry, medicine, biology and agriculture. More than 330 talks were presented in the meeting. (k.m.)

Abstracts of the third Eurasian conference on nuclear science and its application

Energy Technology Data Exchange (ETDEWEB)

Yuldashev, B; Salikhbaev, U; Ibragimova, E; Fazylov, M [eds.

2004-10-01

The third Eurasian conference on nuclear science and its application was held on 5-8 October, 2004 in Tashkent, Uzbekistan. The specialists discussed various aspects of modern problems of particle physics, relativistic nuclear physics and physics of atomic nuclei, radiochemistry, radioisotope production, technology of radioisotopes and compounds, activations analysis applications, radionuclides, radioimmunoassays, application of radioisotopes in industry, medicine, biology and agriculture. More than 330 talks were presented in the meeting. (k.m.)

Cryptosporidium suis and Cryptosporidium scrofarum in Eurasian wild boars (Sus scrofa) in Central Europe

Czech Academy of Sciences Publication Activity Database

Němejc, K.; Sak, Bohumil; Květoňová, Dana; Hanzal, V.; Janiszewski, P.; Forejtek, P.; Rajský, D.; Ravaszová, P.; McEvoy, J.; Kváč, Martin

2013-01-01

Roč. 197, 3-4 (2013), s. 504-508 ISSN 0304-4017 Grant - others:Jihočeská univerzita(CZ) 022/2010/Z; Jihočeská univerzita(CZ) 11/2013/Z Institutional support: RVO:60077344 Keywords : Central Europe * Cryptosporidium scrofarum * Cryptosporidium suis * Eurasian wild boar * PCR * SSU Subject RIV: EE - Microbiology, Virology Impact factor: 2.545, year: 2013

Novel Eurasian highly pathogenic influenza A H5 viruses in wild birds, Washington, USA

Science.gov (United States)

Ip, Hon S.; Kim Torchetti, Mia; Crespo, Rocio; Kohrs, Paul; DeBruyn, Paul; Mansfield, Kristin G.; Baszler, Timothy; Badcoe, Lyndon; Bodenstein, Barbara L.; Shearn-Bochsler, Valerie I.; Killian, Mary Lea; Pederson, Janice C.; Hines, Nichole; Gidlewski, Thomas; DeLiberto, Thomas; Sleeman, Jonathan M.

2015-01-01

Novel Eurasian lineage avian influenza A(H5N8) virus has spread rapidly and globally since January 2014. In December 2014, H5N8 and reassortant H5N2 viruses were detected in wild birds in Washington, USA, and subsequently in backyard birds. When they infect commercial poultry, these highly pathogenic viruses pose substantial trade issues.

Who is who: An anomalous predator-prey role exchange between cyprinids and perch.

Czech Academy of Sciences Publication Activity Database

Vejřík, Lukáš; Matějíčková, Ivana; Seďa, Jaromír; Blabolil, Petr; Jůza, Tomáš; Vašek, Mojmír; Ricard, Daniel; Matěna, Josef; Frouzová, Jaroslava; Kubečka, Jan; Říha, Milan; Čech, Martin

2016-01-01

Roč. 11, č. 6 (2016), č. článku e0156430. E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) EE2.3.20.0204; GA MŠk(CZ) 7F14316; GA ČR GP206/09/P266; GA ČR GA15-24309S; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Abramis brama * Cyprinus carpio * piscivory * YOY perch * zooplankton Subject RIV: DA - Hydrology ; Limnology Impact factor: 2.806, year: 2016

Effect of boat noise and angling on lake fish behaviour

DEFF Research Database (Denmark)

Jacobsen, Lene; Baktoft, Henrik; Jepsen, Niels

2014-01-01

or (2) boating in short intervals combined with angling with artificial lures between engine runs. The response of the fish species was evaluated by high-resolution tracking using an automatic acoustic telemetry system and transmitters with sub-minute burst rates. Rutilus rutilus swimming speed......The effects of disturbances from recreational activities on the swimming speed and habitat use of roach Rutilus rutilus, perch Perca fluviatilis and pike Esox lucius were explored. Disturbances were applied for 4h as (1) boating in short intervals with a small outboard internal combustion engine...... the two types of disturbances (boating with and without angling), indicating that boating was the primary source of disturbance. This study highlights species-specific responses to recreational boating and may have implications for management of human recreational activities in lakes...

Occurrence of Flavobacterium psychrophilum in fish-farming environments

DEFF Research Database (Denmark)

Madetoja, J.; Dalsgaard, Inger; Wiklund, T.

2002-01-01

Occurrence of Flavobacterium psychrophilum in fish farms and fish-farming environments was studied using agar plate cultivation,the immunoflourescence antibody technique (IFAT) and nested PCR. Characteristics of 64 F. psychrophilum isolates from rainbow trout Oncorhynchus mykiss, fish farm rearing....... F. psychrophilum was detected and isolated from skin mucus, skin lesions and internal organs of diseased rainbow trout and from fish without clinical disease. The pathogen was also present in wild perch Perca fluviatilis, roach Rutilus rutilus, and ovarian fluids of farmed rainbow trout brood fish...... ribopatterns), ribotype A was the most dominant. Farmed rainbow trout brood fish carried a broad-spectrum of serologically and genetically different F. psychrophilum in ovarian fluids. Virulence of the tested isolates in rainbow trout varied and naturally infected rainbow trout shed 104 to 108 cells fish-1 h-1...

Virulence of viral hemorrhagic septicemia virus (VHSV) genotypes Ia, IVa, IVb, and IVc in five fish species.

Science.gov (United States)

Emmenegger, Eveline J.; Moon, Chang Hoon; Hershberger, Paul K.; Kurath, Gael

2013-01-01

The susceptibility of yellow perch Perca flavescens, rainbow trout Oncorhynchus mykiss, Chinook salmon O. tshawytscha, koi Cyprinus carpio koi, and Pacific herring Clupea pallasii to 4 strains of viral hemorrhagic septicemia virus (VHSV) was assessed. Fish were challenged via intraperitoneal injection with high (1 × 106 plaque-forming units, PFU) and low (1 × 103 PFU) doses of a European strain (genotype Ia), and North American strains from the West coast (genotype IVa), Great Lakes (genotype IVb), and the East coast (genotype IVc). Pacific herring were exposed to the same VHSV strains, but at a single dose of 5 × 103 PFU ml-1 by immersion in static seawater. Overall, yellow perch were the most susceptible, with cumulative percent mortality (CPM) ranging from 84 to 100%, and 30 to 93% in fish injected with high or low doses of virus, respectively. Rainbow trout and Chinook salmon experienced higher mortalities (47 to 98% CPM) after exposure to strain Ia than to the other virus genotypes. Pacific herring were most susceptible to strain IVa with an average CPM of 80% and moderately susceptible (42 to 52% CPM) to the other genotypes. Koi had very low susceptibility (≤5.0% CPM) to all 4 VHSV strains. Fish tested at 7 d post challenge were positive for all virus strains, with yellow perch having the highest prevalence and concentrations of virus, and koi the lowest. While genotype Ia had higher virulence in salmonid species, there was little difference in virulence or host-specificity between isolates from subtypes IVa, IVb, and IVc.  

Total Mercury and Methylmercury Contamination in Fish from Sites along the Elbe River

Directory of Open Access Journals (Sweden)

P. Maršálek

2006-01-01

Full Text Available The aim of the study was to evaluate total mercury Hg and methylmercury MeHg contamination in muscle tissues of fish collected in 2002 from the Labe (Elbe river at sites upstream of Pardubice and downstream of Pardubice and Hřensko, and in 2004 from the Labe river upstream and downstream of the Spolana factory in Neratovice, and from the Vltava river downstream of Lenora. Eighty eight fish of the following species were sampled: bream (Abramis brama L., perch (Perca fluviatilis L., chub (Leuciscus cephalus L. and barbel (Barbus barbus L.. Total mercury content in chub, perch and bream was in the range of 0.05 - 1.96 mg kg-1 w.w., 0. 09 - 1.46 mg kg-1 w.w. and 0.35 - 0.82 mg kg-1 w.w., respectively. Methylmercury content in chub, perch and bream was in the range of 0.04 - 2.11 mg kg-1 w.w., 0.1 - 1.73 mg kg-1 w.w. and 0.371 - 0.650 mg kg-1 w.w., respectively. Significant correlation (p p < 0.05 between THg and MeHg contents were found between individual sites. In 2002, for example, the most contaminated fish were found downstream of Pardubice, followed by fish from upstream of Pardubice and from Hřensko. In 2004, fish from downstream and upstream of the Spolana factory in Neratovice were more contaminated than fish from the Vltava river downstream of Lenora. The methylmercury-tototal mercury ratio in muscle tissue was close to 1.0.

Research on the changes of some physiological parameters in several fish species under the action of the talstar insecticide

Directory of Open Access Journals (Sweden)

Maria Cristina PONEPAL

2010-05-01

Full Text Available Talstar insecticide is labeled for numerous bugs and many other household pests and lawn pests. Bifenthrin is highly toxic to fish and aquatic arthropods. Bifenhrin LC50 values range from 0.0038 to17.8 μg/L and is only slightly toxic to both waterfowl and upland game birds (LD50 values range from 1.800 mg/kg to > 2.150 mg/kg. Bifenthrin had no effect on mollusks at its limit of water solubility. This study was carried out to analyze the effects of sublethal and lethal concentrations – from 0.000625 to 0.005 ml Talstar/l water on some physiological parameters (oxygen consumption, breathing frequency, number of erythrocytes on fish belonging to three species: prussian carp (Carassius auratus gibelio Bloch, bleak (Alburnus alburnus L. and perch (Perca fluviatilis L.. The acute and subacute toxicity of Talstar insecticide was evaluated in glass aquaria under semystatic conditions. The Tlastar product, under the concentrations from 0.000625 to 0.005 ml/l water, produces, after one week of immersion, a significant decrease of the fish oxygen consumption. The insecticide has changed the fish respiratory rhythm in all investigated concentrations after seven days of exposure. The number of erythrocytes has significantly decrease after seven days of immersion at insecticide concentrations of 0.000625 ml Talstar/l water (bleak and perch and 0.00125 (prussian carp ml Talstar/l water. From the three investigated fish species, the perch proved to be the most sensitive to the action of the toxic substance, followed by the bleak and the prussian carp.

Performance of free-range chickens reared in production modules enriched with shade net and perches

Directory of Open Access Journals (Sweden)

MJB Santos

2014-03-01

Full Text Available An experiment was carried out to evaluate the effect of environmental enrichment in a free-range chicken production system on live performance as a function of microclimate, physiological parameters, and performance parameters. Four production modules were divided into four pens with 10 birds each, totaling 60 birds. The following treatments were applied: access to a paddock (TEST, access to a paddock with perches (PER, access to a paddock with artificial shade (SHA, and access to the paddock with perches and artificial shade (PESH. The PESH production module presented the best globe temperature (Tbg,ºC and enthalpy (h, kJ/kg, and thereby, the best thermal environmental conditions, which ensured the longest permanence time of the birds in the paddock. The SHA and PESH modules promoted the lowest respiratory rate and shank and comb temperatures. Live performance was influenced by the presence of environmental enrichment (modules SHA and PESH, with the highest live weight (LW and weight gain (WG and the lowest feed conversion ratio (FCR and metabolizable energy intake (MEI. Parts yield, such as giblets, were not influenced by production modules, except for PESH, which promoted higher offal weight. In general, chickens reared in enriched production modules presented greatest performance and comfort results and were considered close to optimal rearing conditions.

DNA barcode for genetic traceability of Nile Perch and Nile Tilapia

International Nuclear Information System (INIS)

Avossa, Valeria

2017-01-01

For this study, mitochondrial DNA was extracted from 55 fish samples (26 Nile Perch Samples and 29 Nile Tilapia Samples collected from 3 different Ugandan regions of Lake Victoria. In order to optimize the PCR method, we also extracted DNA from two other different fish samples: one from Italy and one from a Viennese market. The COI gene was amplified using universal primers (COI2, COI3, cocktails of 8 and 4 primers respectively). After the amplification step, the amplicons were analysed using gel electrophoresis , in order to establish that the set primers worked well in the samples. The positive results of an agarose gel electrophoresis analysis with the PCR amplicons (amplicons length ~700pb) are shown.

Can species-specific prey responses to chemical cues explain prey susceptibility to predation?

Science.gov (United States)

Šmejkal, Marek; Ricard, Daniel; Sajdlová, Zuzana; Čech, Martin; Vejřík, Lukáš; Blabolil, Petr; Vejříková, Ivana; Prchalová, Marie; Vašek, Mojmír; Souza, Allan T; Brönmark, Christer; Peterka, Jiří

2018-05-01

The perception of danger represents an essential ability of prey for gaining an informational advantage over their natural enemies. Especially in complex environments or at night, animals strongly rely on chemoreception to avoid predators. The ability to recognize danger by chemical cues and subsequent adaptive responses to predation threats should generally increase prey survival. Recent findings suggest that European catfish ( Silurus glanis ) introduction induce changes in fish community and we tested whether the direction of change can be attributed to differences in chemical cue perception. We tested behavioral response to chemical cues using three species of freshwater fish common in European water: rudd ( Scardinius erythrophthalmus ), roach ( Rutilus rutilus ), and perch ( Perca fluviatilis ). Further, we conducted a prey selectivity experiment to evaluate the prey preferences of the European catfish. Roach exhibited the strongest reaction to chemical cues, rudd decreased use of refuge and perch did not alter any behavior in the experiment. These findings suggest that chemical cue perception might be behind community data change and we encourage collecting more community data of tested prey species before and after European catfish introduction to test the hypothesis. We conclude that used prey species can be used as a model species to verify whether chemical cue perception enhances prey survival.

Determination of 90Sr and 210Pb in freshwater fish in Austria

International Nuclear Information System (INIS)

Claudia Landstetter; Merita Sinojmeri; Christian Katzlberger; Arno Achatz

2014-01-01

A method for the determination of 90 Sr and 210 Pb in freshwater fish was developed. The determinations were conducted within a project on behalf of the Federal Ministry of Health. The aim of this project was to get an overview of the activity concentrations of natural and artificial radionuclides in freshwater fish in different lakes in Austria. For sampling the Neusiedler See in Burgenland, two lakes in Styria the Grundlsee and the Toplitz See, and the Zeller See in Salzburg were chosen. Chub (Leuciscus cephalus), pike (Esox lucius), perch (Perca fluviatilis), carp (Cyprinus carpio), catfish (Silurus glanis), pike-perch (Sander lucioperca) and burbot (Lota lota) were analysed. The samples were analysed using strontium specific extraction columns (Eichrom Industries Inc., TrisKem International) and liquid scintillation counting. In the edible parts of the fish samples (no fishbone) values of the activity concentration for 210 Pb varied between 0.009 ± 0.003 and 0.16 ± 0.04 Bq kg freshweight -1 and for 90 Sr between 0.010 ± 0.002 and 0.11 ± 0.02 Bq kg freshweight -1 . In this paper the method for the determination of 90 Sr and 210 Pb is described and the results are discussed. (author)

INTERESTS OF THE MEMBER STATES IN THE EURASIAN ECONOMIC UNION

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Tomasz Michałowski

2016-12-01

Full Text Available The article presents the interests of the member countries in the Eurasian Economic Union (EEU, which is formed by Russia, Belarus, Kazakhstan, Armenia and Kyrgyzstan. The author argues that Russia has been involved in the project primarily for geopolitical reasons. Belarus, Kazakhstan, Armenia and Kyrgyzstan have perceived the integration within EEU primarily through the possible economic benefits. While analyzing the interests of the members in the EEU, the author also refers to the development of the economic situation in each country in recent years. The starting point for discussion is the analysis of benefits of economic integration in the light of theory.

The Eurasian Economic Union and the Silk Road Economic Belt: Players, Interests and Implementation Challenges

Directory of Open Access Journals (Sweden)

Andrei Skriba

2016-11-01

Full Text Available In May 2015, Russia and China coordinated their activities in Central Asia and decided to connect the Eurasian EconomicUnion (EEU and the Silk Road Economic Belt. This decision seemed to prevent unnecessary competition between these two basically non-conflicting projects. However, in time there appeared a lack of understanding of this combined endeavour and its implementation mechanisms. It is still unclear how further dialogue between the EEU and the Silk Road will proceed. There is no consensuson the participation of the EEU members and the Eurasian Economic Commission. Without a clear strategy, the Russian-Chinese agreement has started to lose momentum. Some non-regional players can benefit from this – of course, in their own interests.This articles attempt to explain the threats posed by delay and inaction in the combined EEU and Silk Road projects, and to describe the potential benefits of actively implementing the combination. It then proposes a concrete format for such a combination, its priority areas, as well as mechanisms for implementation.

The Eurasian Economic Union: A Brittle Roadblock on China's "One Belt - One Road"

DEFF Research Database (Denmark)

Zank, Wolfgang

2017-01-01

is not compatible with the OBOR initiative. A free-trade agreement between China and the EEU could make it compatible, but this is not a realistic perspective for the near future. The EEU seems to be an unstable construction, with many basic rules and norms being unclear, and many tensions and conflicts among its...... members. Keywords: China, European-Atlantic Security Community, Eurasian Economic Union, “One Belt One Road” Initiative, Russia’s “Monroe Doctrine”....

Molecular evidence for association of chlamydiales bacteria with epitheliocystis in leafy seadragon (Phycodurus eques), silver perch (Bidyanus bidyanus), and barramundi (Lates calcarifer).

NARCIS (Netherlands)

Meijer, Adam; Roholl, Paul J M; Ossewaarde, Jacobus M; Jones, Brian; Nowak, Barbara F

2006-01-01

Epitheliocystis in leafy seadragon (Phycodurus eques), silver perch (Bidyanus bidyanus), and barramundi (Lates calcarifer), previously associated with chlamydial bacterial infection using ultrastructural analysis, was further investigated by using molecular and immunocytochemical methods.

An update of hydrologic conditions and distribution of selected constituents in water, Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2006-08

Science.gov (United States)

Davis, Linda C.

2010-01-01

Since 1952, radiochemical and chemical wastewater discharged to infiltration ponds (also called percolation ponds), evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains groundwater monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from aquifer and perched groundwater wells in the USGS groundwater monitoring networks during 2006-08. Water in the Snake River Plain aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer primarily is recharged from infiltration of irrigation water, infiltration of streamflow, groundwater inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March-May 2005 to March-May 2008, water levels in wells generally remained constant or rose slightly in the southwestern corner of the INL. Water levels declined in the central and northern parts of the INL. The declines ranged from about 1 to 3 feet in the central part of the INL, to as much as 9 feet in the northern part of the INL. Water levels in perched groundwater wells around the Advanced Test Reactor Complex (ATRC) also declined. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 2006-08. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal, radioactive decay, changes in waste-disposal methods, and dilution from recharge and underflow. In April

An Update of Hydrologic Conditions and Distribution of Selected Constituents in Water, Snake River Plain Aquifer and Perched-Water Zones, Idaho National Laboratory, Idaho, Emphasis 2002-05

Science.gov (United States)

Davis, Linda C.

2008-01-01

Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds, evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the Snake River Plain aquifer and perched-water zones underlying the INL. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains ground-water monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched-water zones. This report presents an analysis of water-level and water-quality data collected from aquifer and perched-water wells in the USGS ground-water monitoring networks during 2002-05. Water in the Snake River Plain aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer is recharged primarily from infiltration of irrigation water, infiltration of streamflow, ground-water inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March-May 2001 to March-May 2005, water levels in wells declined throughout the INL area. The declines ranged from about 3 to 8 feet in the southwestern part of the INL, about 10 to 15 feet in the west central part of the INL, and about 6 to 11 feet in the northern part of the INL. Water levels in perched water wells declined also, with the water level dropping below the bottom of the pump in many wells during 2002-05. For radionuclides, concentrations that equal 3s, wheres s is the sample standard deviation, represent a measurement at the minimum detectable concentration, or 'reporting level'. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 2002-05. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal

Simulation of Forest Cover Dynamics for Eastern Eurasian Boreal Forests

Science.gov (United States)

Shugart, H. H.; Yan, X.; Zhang, N.; Isaev, A. S.; Shuman, J. K.

2006-12-01

We are developing and testing a boreal zone forest dynamics model capable of simulating the forest cover dynamics of the Eurasian boreal forest, a major biospheric ecosystem with potentially large roles in the planetary carbon cycle and in the feedback between terrestrial surface and the atmosphere. In appreciating the role of this region in the coupling between atmosphere and terrestrial surface, on must understand the interactions between CO2 source/sink relationships (associated with growing or clearing forests) and the albedo effects (from changes in terrestrial surface cover). There is some evidence that in the Eurasian Boreal zone, the Carbon budget effects from forest change may oppose the albedo changes. This creates complex feedbacks between surface and atmosphere and motivates the need for a forest dynamics model that simultaneous represents forest vegetation and carbon storage and release. A forest dynamics model applied to Eastern Eurasia, FAREAST, has been tested using three types of information: 1. Direct species composition comparisons between simulated and observed mature forests at the same locations; 2. Forest type comparisons between simulated and observed forests along altitudinal gradients of several different mountains; 3. Comparison with forest stands in different succession stages of simulated forests. Model comparisons with independent data indicate the FAREAST model is capable of representing many of the broad features of the forests of Northeastern China. After model validation in the Northeast China region, model applications were developed for the forests of the Russian Far East. Continental-scale forest cover can be simulated to a relatively realistic degree using a forest gap model with standard representations of individual-plant processes. It appears that such a model, validated relatively locally in this case, in Northeastern China, can then be applied over a much larger region and under conditions of climatic change.

Revealing turning points in ecosystem functioning over the Northern Eurasian agricultural frontier.

Science.gov (United States)

Horion, Stéphanie; Prishchepov, Alexander V; Verbesselt, Jan; de Beurs, Kirsten; Tagesson, Torbern; Fensholt, Rasmus

2016-08-01

The collapse of the Soviet Union in 1991 has been a turning point in the World history that left a unique footprint on the Northern Eurasian ecosystems. Conducting large scale mapping of environmental change and separating between naturogenic and anthropogenic drivers is a difficult endeavor in such highly complex systems. In this research a piece-wise linear regression method was used for breakpoint detection in Rain-Use Efficiency (RUE) time series and a classification of ecosystem response types was produced. Supported by earth observation data, field data, and expert knowledge, this study provides empirical evidence regarding the occurrence of drastic changes in RUE (assessment of the timing, the direction and the significance of these changes) in Northern Eurasian ecosystems between 1982 and 2011. About 36% of the study area (3.4 million km(2) ) showed significant (P agricultural land abandonment. Our study also showed that recurrent droughts deeply affected vegetation productivity throughout the observation period, with a general worsening of the drought conditions in recent years. Moreover, recent human-induced turning points in ecosystem functioning were detected and attributed to ongoing recultivation and change in irrigation practices in the Volgograd region, and to increased salinization and increased grazing intensity around Lake Balkhash. The ecosystem-state assessment method introduced here proved to be a valuable support that highlighted hotspots of potentially altered ecosystems and allowed for disentangling human from climatic disturbances. © 2016 John Wiley & Sons Ltd.

Genetic structure within and among regional populations of the Eurasian badger (Meles meles) from Denmark and the Netherlands

NARCIS (Netherlands)

Van de Zande, Louis; van Vliet, Michel; Pertoldi, C.; Loeschcke, V.; Muskens, G; Bijlsma, R.

The Eurasian badger Meles meles has a wide distribution area ranging from Japan to Ireland. In western Europe badger habitats are severely disturbed by anthropogenic factors, leading to fragmentation into subpopulations and formation of a metapopulation substructuring of once continuous panmictic

Genetic structure within and among regional populations of the Eurasian badger (Meles meles) from Denmark and the Netherlands

NARCIS (Netherlands)

Zande, van de L.; Vliet, van de M.; Pertoldi, C.; Loeschcke, V.; Muskens, G.; Bijlsma, R.

2007-01-01

The Eurasian badger Meles meles has a wide distribution area ranging from Japan to Ireland. In western Europe badger habitats are severely disturbed by anthropogenic factors, leading to fragmentation into subpopulations and formation of a metapopulation substructuring of once continuous panmictic

Expansion of an exotic species and concomitant disease outbreaks: pigeon paramyxovirus in free-ranging Eurasian collared doves.

Science.gov (United States)

Schuler, Krysten L; Green, David E; Justice-Allen, Anne E; Jaffe, Rosemary; Cunningham, Mark; Thomas, Nancy J; Spalding, Marilyn G; Ip, Hon S

2012-06-01

Eurasian collared doves (Streptopelia decaocto) have expanded their range across the United States since their introduction several decades ago. Recent mortality events in Eurasian collared doves in Arizona and Montana, USA, during the winter of 2009-2010 were the result of pigeon paramyxovirus (PPMV), a novel disease agent. The first instance of mortality by this emerging infectious disease in this species occurred in Florida in 2001 with subsequent disease events in 2006 and 2008. Full diagnostic necropsies were performed on carcasses from the three states. PPMV was identified by RT-PCR and virus isolation and was sequenced to the VIb genotype of avian paramyxovirus-1 (APMV). Other APMVs are common in a variety of free-ranging birds, but concern is warranted because of the potential for commingling of this species with native birds, virus evolution, and threats to domestic poultry. Improved surveillance for wildlife mortality events and efforts to prevent introduction of non-native animals could reduce the threat of introducing new pathogens.

Distribution and Abundance of Eurasian Watermilfoil (Myriophyllum spicatum L.) and Curly-Leaf Pondweed (Potamogeton crispus L.) in Shawano Lake, Wisconsin

National Research Council Canada - National Science Library

Owens, Chetta S; James, William F; Skogerboe, John G; Smart, R. M

2007-01-01

... (Potamogeton crispus L.) and Eurasian watermilfoil (Myriophyllum spicatum L.). In addition to problems associated with invasive plant species, Shawano Lake has been experiencing declining water quality associated with phosphorus (P...

Evolution of the Eurasian Ice Sheets during the Last Deglaciation (25-10 kyr)

Science.gov (United States)

Hughes, A. L. C.; Gyllencreutz, R.; Mangerud, J.; Svendsen, J. I.; Lohne, Ø. S.

2014-12-01

Both the timing of maximum extent and subsequent pace of retreat of the interconnected Eurasian (British-Irish, Scandinavian, Svalbard-Barents-Kara Sea) Ice Sheets were spatially variable likely reflecting contrasts in response to forcing mechanisms, geographical settings and glacial dynamics both between individual ice sheets and ice-sheet sectors. For example the maximum limit along the western continental shelf edge was reached up to 3,000 years earlier than the maximum, mainly terrestrial, limits in the east. We present new time-slice reconstructions of the ice-sheet evolution through the last deglaciation based on a compiled chronology of over 5,000 dates and published ice-margin positions. Ice-sheet margins are depicted every 1,000 years (25-10 kyr) and include uncertainty estimates (represented by maximum, minimum and most-credible lines). The new ice-sheet scale reconstructions summarise and provide the means for direct comparison of the empirical geological record against simulations of the deglacial ice-sheet evolution from numerical and isostatic ice-sheet modelling and the timing of abrupt events observed in deglacial climate and ocean records. The reconstruction process has identified both instances of conflicting evidence and gaps in the geological record that should be a focus for future studies. This work is part of an on-going project to reconstruct the changing limits of the Eurasian Ice Sheets through the last glacial cycle (www.uib.no/project/dated).

Spatiotemporal variability of snow depth across the Eurasian continent from 1966 to 2012

Science.gov (United States)

Zhong, Xinyue; Zhang, Tingjun; Kang, Shichang; Wang, Kang; Zheng, Lei; Hu, Yuantao; Wang, Huijuan

2018-01-01

Snow depth is one of the key physical parameters for understanding land surface energy balance, soil thermal regime, water cycle, and assessing water resources from local community to regional industrial water supply. Previous studies by using in situ data are mostly site specific; data from satellite remote sensing may cover a large area or global scale, but uncertainties remain large. The primary objective of this study is to investigate spatial variability and temporal change in snow depth across the Eurasian continent. Data used include long-term (1966-2012) ground-based measurements from 1814 stations. Spatially, long-term (1971-2000) mean annual snow depths of >20 cm were recorded in northeastern European Russia, the Yenisei River basin, Kamchatka Peninsula, and Sakhalin. Annual mean and maximum snow depth increased by 0.2 and 0.6 cm decade-1 from 1966 through 2012. Seasonally, monthly mean snow depth decreased in autumn and increased in winter and spring over the study period. Regionally, snow depth significantly increased in areas north of 50° N. Compared with air temperature, snowfall had greater influence on snow depth during November through March across the former Soviet Union. This study provides a baseline for snow depth climatology and changes across the Eurasian continent, which would significantly help to better understanding climate system and climate changes on regional, hemispheric, or even global scales.

INVESTIGATION OF b-VALUE VARIATIONS IN THE AFRICAN AND PARTS OF EURASIAN PLATES

Directory of Open Access Journals (Sweden)

Awoyemi, M. O.

2017-06-01

Full Text Available Numerous earthquakes have occurred along the collision zones of the African and parts of Eurasian plates. Some of these earthquakes along these zones have generated tsunamis. To mitigate this hazard, knowledge of b-values of the Gutenberg – Richter relation for tectonic earthquakes in the African and parts of Eurasian plates is essential. The temporal variations of b-values were evaluated using sliding time windows with each window containing a total of 100 events with a view to utilizing the results as a precursor for the earthquake occurrence. The spatial variation of b-values of the study area was also delineated by dividing it into grids and calculating the b-values for each grid using constant radius and constant number of events. Results obtained from the temporal variation of b-values showed that earthquakes of large magnitudes occurred when the b-values were low while earthquakes of small magnitudes occurred when the b-values were high throughout the study period. The results of the spatial distribution of b-values also showed that earthquakes of large magnitudes occurred in areas of low b-values while earthquakes of small magnitudes occurred in areas of high b-values. The study therefore concluded that the temporal and spatial variations of b-values might be considered as a precursor for earthquake prediction.

Physiological and ecological factors influencing the radiocaesium contamination of fish species from Kiev reservoir

Energy Technology Data Exchange (ETDEWEB)

Koulikov, A.O. [A.N. Severtzov Institute of Evolutionary Morphology and Ecology of Animals, Russian Academy of Sciences, Moscow (Russian Federation)

1995-11-23

The monitoring of {sup 137}Cs contamination of fish from the northern part of the Kiev reservoir between 1987 and 1992 indicated systematic differences in the long-term average contamination levels of different species, which are closely related to their trophic levels. The average contamination of the predatory species: perch (Perca fluviatilis) and pike (Esox lucius) were roughly factors of 6.3 and 4.4 respectively, higher than those of the nonpredatory species: bream (Abramis brama), silver bream (Blicca bjoerkna) and rudd (Scardinius erythrophothalmus). For tench (Tinca tinca) and goldfish (Carassius sp.), this factor is 2. The solution of the caesium balance equation in fish obtained for equilibrium conditions, which is applicable to the long-term contamination, provides some explanations for these accumulation differences between the species with respect to influences by different ecological and physiological factors.

A Mainly Circum-Mediterranean Origin for West Eurasian and North African mtDNAs in Puerto Rico with Strong Contributions from the Canary Islands and West Africa.

Science.gov (United States)

Díaz-Zabala, Héctor J; Nieves-Colón, María A; Martínez-Cruzado, Juan C

2017-04-01

Maternal lineages of West Eurasian and North African origin account for 11.5% of total mitochondrial ancestry in Puerto Rico. Historical sources suggest that this ancestry arrived mostly from European migrations that took place during the four centuries of the Spanish colonization of Puerto Rico. This study analyzed 101 mitochondrial control region sequences and diagnostic coding region variants from a sample set randomly and systematically selected using a census-based sampling frame to be representative of the Puerto Rican population, with the goal of defining West Eurasian-North African maternal clades and estimating their possible geographical origin. Median-joining haplotype networks were constructed using hypervariable regions 1 and 2 sequences from various reference populations in search of shared haplotypes. A posterior probability analysis was performed to estimate the percentage of possible origins across wide geographic regions for the entire sample set and for the most common haplogroups on the island. Principal component analyses were conducted to place the Puerto Rican mtDNA set within the variation present among all reference populations. Our study shows that up to 38% of West Eurasian and North African mitochondrial ancestry in Puerto Rico most likely migrated from the Canary Islands. However, most of those haplotypes had previously migrated to the Canary Islands from elsewhere, and there are substantial contributions from various populations across the circum-Mediterranean region and from West African populations related to the modern Wolof and Serer peoples from Senegal and the nomad Fulani who extend up to Cameroon. In conclusion, the West Eurasian mitochondrial ancestry in Puerto Ricans is geographically diverse. However, haplotype diversity seems to be low, and frequencies have been shaped by population bottlenecks, migration waves, and random genetic drift. Consequently, approximately 47% of mtDNAs of West Eurasian and North African ancestry

Macroscopic and microscopic evaluation of Eurasian lynx (Lynx lynx) female tubular reproductive organs in relation to ovarian structures.

Science.gov (United States)

Axnér, E; Holm, D; Gavier-Widén, D; Söderberg, A; Bergqvist, A S

2015-09-15

Although monitoring wild animals in the field is essential for estimations of population size and development, there are pitfalls associated with field monitoring. In addition, some detailed data about reproductive physiology can be difficult to obtain in wild live animals. Studying reproductive organs from the Eurasian lynx killed at hunting or found dead could be used as a valuable addition to other field data. We evaluated reproductive organs from 39 Eurasian lynx females (Lynx lynx) killed in Sweden during the hunting seasons in 2009, 2010, and 2011. According to notes on ovarian structures, the animals were categorized as being in one of four different reproductive stages: juvenile (n = 10), follicular stage (n = 8), luteal stage (n = 11), and anestrus (n = 10). Corpora lutea were classified as fresh CL from the present season or as luteal bodies from previous cycles. Microscopic evaluations were blindly coded while the outer measurements of the vagina and uterus were taken at the time of organ retrieval. The width of the endometrium, myometrium, outer width of the uterine horns, and the diameter of the vagina differed significantly with the reproductive stage (P number of endometrial glands evaluated blindly coded on a subjective scale was significantly associated with the reproductive stage (P reproductive stages (P reproductive stage when evaluating reproductive organs in the Eurasian lynx killed during the hunting season. Routine evaluation of reproductive organs has a potential to be a useful additional tool to field studies of live lynx to monitor their reproduction. Copyright © 2015 Elsevier Inc. All rights reserved.

Novel Eurasian highly pathogenic avian influenza A H5 viruses in wild birds, Washington, USA, 2014.

Science.gov (United States)

Ip, Hon S; Torchetti, Mia Kim; Crespo, Rocio; Kohrs, Paul; DeBruyn, Paul; Mansfield, Kristin G; Baszler, Timothy; Badcoe, Lyndon; Bodenstein, Barbara; Shearn-Bochsler, Valerie; Killian, Mary Lea; Pedersen, Janice C; Hines, Nichole; Gidlewski, Thomas; DeLiberto, Thomas; Sleeman, Jonathan M

2015-05-01

Novel Eurasian lineage avian influenza A(H5N8) virus has spread rapidly and globally since January 2014. In December 2014, H5N8 and reassortant H5N2 viruses were detected in wild birds in Washington, USA, and subsequently in backyard birds. When they infect commercial poultry, these highly pathogenic viruses pose substantial trade issues.

Organohalogen exposure in a Eurasian owl (Bubo bubo) population from Southeastern Spain: Temporal-spatial trends and risk assessment

NARCIS (Netherlands)

Gomez-Ramirez, P.; Martinez-Lopez, E.; Garcia-Fernandez, A.; Zweers, A.J.; Brink, van den N.W.

2012-01-01

Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine insecticides (OCs) were analysed in 58 Eurasian Eagle owl (Bubo bubo) unhatched eggs collected between 2004 and 2009 in Southeastern Spain. Levels of p,p'-DDE were found to be higher than in eggs laid by

Microbiological performance of Hazard Analysis Critical Control Point (HACCP)-based food safety management systems: A case of Nile perch processing company

NARCIS (Netherlands)

Kussaga, J.B.; Luning, P.A.; Tiisekwa, B.P.M.; Jacxsens, L.

2017-01-01

This study aimed at giving insight into microbiological safety output of a Hazard Analysis Critical Control Point (HACCP)-based Food Safety Management System (FSMS) of a Nile perch exporting company by using a combined assessment, This study aimed at giving insight into microbiological safety output

WHITHER DEVELOPMENT? THE EFFECTS OF THE EURASIAN UNION ON THE CENTRAL ASIAN REPUBLICS

Directory of Open Access Journals (Sweden)

Adelin Dumitru

2015-12-01

Full Text Available In this paper I analyze the impact of the Eurasian Union on the Central Asian republics, with a focus on remittances trends. To this end I review at first the literature regarding the effects of the Customs Union on its members. Then, I assess the current state of the economies most likely to be affected by membership in the Eurasian Union, i.e. Tajikistan and Kyrgyzstan, whose specificity is their dependency on remittances. Secondly, I present a plausible scenario in regard to the influence of the formalization of this regional organization on the emerging Central Asian regional security subcomplex. I argue that the EEU is a hindrance towards the five Central Asian Republics’ evolving towards a regional security complex. Not only has it already distorted trade in the region, but it can also turn some presently frozen conflicts into security hotspots. I hold that the only way to spur development in the region is, internally, to diversify the economy, and, externally, to bring the five republics closer. I try to show that the Central Asian Republics should simultaneously pursue a switch from a balance of threat to regional integration and sustainable national development. Nonetheless, the EEU will have at best mixed effects when it comes to these necessities. Alternatively, China and the New Silk Road initiative that it endorses might contribute to de-securitizing some of the existing issues.

Planktonic or non-planktonic food in young-of-the-year European perch Perca fluviatilis in ponds

Czech Academy of Sciences Publication Activity Database

Bláha, M.; Šetlíková, I.; Peterka, Jiří; Musil, J.; Policar, T.

2014-01-01

Roč. 85, č. 2 (2014), s. 509-515 ISSN 0022-1112 Institutional support: RVO:60077344 Keywords : aquatic macrophytes * phytophilous zoobenthos * sediment zoobenthos * semi-intensive fish Subject RIV: GL - Fishing Impact factor: 1.658, year: 2014

The sensitivity of the Late Saalian (140 ka) and LGM (21 ka) Eurasian ice sheets to sea surface conditions

Energy Technology Data Exchange (ETDEWEB)

Colleoni, Florence [Centro Euro-Mediterraneo per i Cambiamenti Climatici, Bologna (Italy); UJF, CNRS, Laboratoire de Glaciologie et Geophysique de l' Environnement, Saint Martin d' Heres Cedex (France); Stockholm University, Department of Geological Sciences, Stockhlom (Sweden); Liakka, Johan [Stockholm University, Department of Meteorology, Stockholm (Sweden); Krinner, Gerhard; Peyaud, Vincent [UJF, CNRS, Laboratoire de Glaciologie et Geophysique de l' Environnement, Saint Martin d' Heres Cedex (France); Jakobsson, Martin [Stockholm University, Department of Geological Sciences, Stockhlom (Sweden); Masina, Simona [Centro Euro-Mediterraneo per i Cambiamenti Climatici, Istituto Nazionale di Geofisica e Vulcanologia, Bologna (Italy)

2011-08-15

This work focuses on the Late Saalian (140 ka) Eurasian ice sheets' surface mass balance (SMB) sensitivity to changes in sea surface temperatures (SST). An Atmospheric General Circulation Model (AGCM), forced with two preexisting Last Glacial Maximum (LGM, 21 ka) SST reconstructions, is used to compute climate at 140 and 21 ka (reference glaciation). Contrary to the LGM, the ablation almost stopped at 140 ka due to the climatic cooling effect from the large ice sheet topography. Late Saalian SST are simulated using an AGCM coupled with a mixed layer ocean. Compared to the LGM, these 140 ka SST show an inter-hemispheric asymmetry caused by the larger ice-albedo feedback, cooling climate. The resulting Late Saalian ice sheet SMB is smaller due to the extensive simulated sea ice reducing the precipitation. In conclusion, SST are important for the stability and growth of the Late Saalian Eurasian ice sheet. (orig.)

Isolationism versus Geopolitics: The Dual Role of the Eurasian Economic Union in Global Governance

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Maxim Bratersky

2016-09-01

Full Text Available This article conceptualizes ongoing efforts to develop the Eurasian Economic Union (EEU, initiated by Russia, Belarus and Kazakhstan in 2011. Engaging with two major theoretical perspectives, it establishes to what extent the EEU’s construction and potential expansion is economic regionalism (interpreted also as an isolationist strategy driven by Russia led geopolitical motives. The political-economy debate of Eurasia goes beyond a common tariff area and a common market within the territory of the former USSR. Increasingly, it involves the establishment of a common monetary area. China’s Silk Road Economic Belt is building a foundation for a new Eurasia – one of the global economic and political players of this century. The economic reasons pursued by Russia in its Eurasian initiative are inseparable from economic problems of geopolitical significance. The overarching objective of Russian policy is to establish a regional economic fusion, with significant economic sovereignty and strong political influence; that is, to become the new centre of power in the global economy of the 21st century. Correspondingly, although Russian integration policy in Eurasia has not been formulated in an anti-American way, if it is successful the likely consequence will be the withdrawal of a significant segment of the global market from the economic dominance and political influence of western-led economic blocs.

Mitochondrial genetic diversity of Eurasian red squirrels (Sciurus vulgaris) from Denmark

DEFF Research Database (Denmark)

Madsen, Corrie Lynne; Mouatt, Julia Thidamarth Vilstrup; Fernandez Garcia, Rut

2015-01-01

Melanistic Eurasian red squirrels Sciurus vulgaris are commonly found on the Danish island of Funen. They are thought to represent native Danish squirrel types and are presently under threat from admixture with introduced red squirrels. In response, a conservation program was started in 2009...... that involves the translocation of melanistic squirrels from Funen to the squirrel-free island of Langeland. Using mitochondrial DNA of 101 historical and modern samples from throughout Denmark, we assess for the first time population structure and mitochondrial genetic diversity of Danish squirrels compared...

Regional energy projects in the Eurasian Area

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Vesić Dobrica

2012-03-01

Full Text Available The Eurasian area has a very rich energy reserves, and is characterized by a complex network of relationships between major suppliers and consumers. The central place in this area has Russia as a country richest in energy resources in Eurasia. Beside her, the European Union is the largest economic and political grouping in the world, and a huge consumer of energy. The dynamic development of Chinese economy requires more energy imports by China. Dependence of the European Union and China on imported energy is high and will grow in the future. Russia is the world's dominant natural gas producer and one of the two largest oil producers in the world. Russia is the largest natural gas supplier of the EU and a significant oil and natural gas supplier of China. Energy projects in Eurasia are the result of the need to strengthen the stability of energy supplies, efforts to diversify sources of supply, and the geographic redistribution of Russian oil and gas exports. Although the interests of the main actors often do not agree, the reasons of energy security affect the development of joint energy projects.

Genetic consequences of population decline in Eurasian otter (Lutra lutra) populations in the Czech and Slovak Republics

Czech Academy of Sciences Publication Activity Database

Gettová, Lenka; Hájková, Petra

Supp., - (2011), s. 102 ISSN 0394-1914. [International Otter Colloquium /11./. 30.08.2011-04.09.2011, Pavia] R&D Projects: GA AV ČR KJB600930804 Institutional research plan: CEZ:AV0Z60930519 Keywords : Eurasian otter * population size Subject RIV: EG - Zoology http://www.internationalottercolloquium2010.eu/files/proceedings_iucn_xi_ioc_2011.pdf

The cephalic lateral line system of temperate perches (Perciformes: Percichthyidae from Argentinean Patagonia

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Rocío M. Vega

Full Text Available ABSTRACT The species of Percichthys (Percichthyidae are endemic to southern South America. Some authors have pointed out that the genus includes four valid species, based on the morphology of the head, jaws, and fins. A phylogenetic analysis published by other authors suggests that three of them are morphotypes belonging to the same species, Percichthys trucha (Valenciennes, 1833. The aim of this study is to describe for the first time the morphology of the cephalic seismosensory system of Patagonian perches, and how these characters vary in the three morphotypes, in order to provide morphological elements to analyze the taxonomy of these fish species. Comparisons of the cephalic seismosensory system between juveniles and adults were also conducted. Juvenile and adult specimens were collected in the northwestern Argentinean Patagonia. Specimens were bleached in 5% H2O2 and the canal systems of their cephalic lateral line were filled with hematoxylin. Specimens were deposited in the Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Argentina. The cephalic lateral line of the studied specimens is a widened type of canal systems, is not connected to the trunk lateral line, and consists of preopercular-mandibular canal, infraorbital canal, supraorbital canal, temporal canal, supratemporal canal, and a supraorbital commisure. The number of pores increases during the ontogeny, while their diameters decrease. The number, position and size of infraorbital canal pores showed significant differences among morphotypes and juveniles. The interpopulation variation regarding the number, position, and size of pores seems to signal an ongoing process of speciation, which is the result adaptations to different environmental conditions. Our study contributes to the knowledge of the morphology of percichthids and describes for the first time the seismosensory system of temperate perches.

Post-Russian Eurasia and the proto-Eurasian usage of the Runet in Kazakhstan: A plea for a cyberlinguistic turn in area studies

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Dirk Uffelmann

2011-07-01

The paper discusses the role the Russian-based Runet plays for Eurasian webcommunities outside the Russian Federation, mostly relying on Kazakh material, and asks whether post-colonial anxieties about Russian cultural imperialism through the Runet are justified or not and what the Kazakh, possibly post-colonial strategies of coping with this situation are. Essential to this essay is the notion of cyberimperialism, which combines aspects of media studies with post-colonial studies. The interdisciplinary approach to Internet studies is completed by a linguistic focus on the performativity of language usage online for creating situational language identities. The essay rounds off by offering an analysis of Nursultan Nazarbaev’s ambiguous inclusive-exclusive logic of argumentation and confronting it with Russian Eurasianism.

Quartz OSL dating of late quaternary Chinese and Serbian loess: A cross Eurasian comparison of dust mass accumulation rates

DEFF Research Database (Denmark)

Peric, Zoran; Adolphi, Emma Lagerbäck; Stevens, Thomas

2018-01-01

on multi-millennial timescales, with no detailed examination of dust MAR at the two ends of the Eurasian loess belt on shorter, sub-orbital scales. Here we present a detailed quartz optically stimulated luminescence (OSL) chronology from the Serbian Titel Loess Plateau (Veliki Surduk loess core...

Hawk eyes II: diurnal raptors differ in head movement strategies when scanning from perches.

Science.gov (United States)

O'Rourke, Colleen T; Pitlik, Todd; Hoover, Melissa; Fernández-Juricic, Esteban

2010-09-22

Relatively little is known about the degree of inter-specific variability in visual scanning strategies in species with laterally placed eyes (e.g., birds). This is relevant because many species detect prey while perching; therefore, head movement behavior may be an indicator of prey detection rate, a central parameter in foraging models. We studied head movement strategies in three diurnal raptors belonging to the Accipitridae and Falconidae families. We used behavioral recording of individuals under field and captive conditions to calculate the rate of two types of head movements and the interval between consecutive head movements. Cooper's Hawks had the highest rate of regular head movements, which can facilitate tracking prey items in the visually cluttered environment they inhabit (e.g., forested habitats). On the other hand, Red-tailed Hawks showed long intervals between consecutive head movements, which is consistent with prey searching in less visually obstructed environments (e.g., open habitats) and with detecting prey movement from a distance with their central foveae. Finally, American Kestrels have the highest rates of translational head movements (vertical or frontal displacements of the head keeping the bill in the same direction), which have been associated with depth perception through motion parallax. Higher translational head movement rates may be a strategy to compensate for the reduced degree of eye movement of this species. Cooper's Hawks, Red-tailed Hawks, and American Kestrels use both regular and translational head movements, but to different extents. We conclude that these diurnal raptors have species-specific strategies to gather visual information while perching. These strategies may optimize prey search and detection with different visual systems in habitat types with different degrees of visual obstruction.

Prospects for cooperation among the Eurasian Countries and the proliferation concerns of the West

International Nuclear Information System (INIS)

Kibaroglu, M.

2001-01-01

Nuclear science has various applications that improve the quality of life on earth in many respects. Beside its manifold merits, however, perils of nuclear science has also frequently come to the fore in discussions concerning its applications. That is, nuclear science has often been associated with catastrophe rather than prosperity. There are of course understandable reasons for such an approach to nuclear science. Ambitious nuclear programs that were initiated by especially developing countries in the Third World added to the misgivings of ordinary people's concerns of the usefulness and merits of nuclear science and its applications. This has resulted in a considerable opposition in the public domain to new and various investments in the field of nuclear science. This pace has to change and nuclear science and its various applications should be made available to all aspects of life by way of promoting cooperation research and development among nations. With these in mind, we are arriving at a junction where we may make a fresh start to walk along together with the nations in the Eurasian landscape toward a more prosperous future for benefiting from nuclear science and its application. There are reasons to be optimistic. First, with the end of the Cold War and almost the end of the arms race between the so-called nuclear superpowers as a result of finalizing a series of bilateral treaties such as INF and the START I and II, one may conclude that, much less amounts of resources in terms of time, labour and capital will be made available to military applications of nuclear science. It is therefore possible to hope that more and more resources will be allocated to research and development of peaceful applications of nuclear science. To cite one significant development in the field of nuclear disarmament and promoting peaceful applications of nuclear expertise that was accumulated in the military sphere, one could mention the Cooperative Threat Reduction (CTR

Individual migration patterns of Eurasian golden plovers Pluvialis apricaria breeding in Swedish Lapland; examples of cold spell-induced winter movements

NARCIS (Netherlands)

Machin, Paula; Fernandez-Elipe, Juan; Flores, Manuel; Fox, James W.; Aguirre, Jose I.; Klaassen-, Raymond H. G.

2015-01-01

Tracking studies normally focus on long-distance migrants, meaning that our understanding about short-distance migration remains limited. In this study, we present the first individual tracks of the Eurasian golden plover Pluvialis apricaria, a short-distance migrant, which were tracked from a

Individual migration patterns of Eurasian golden plovers Pluvialis apricaria breeding in Swedish Lapland : Examples of cold spell-induced winter movements

NARCIS (Netherlands)

Machin, Paula; Fernandez-Elipe, Juan; Flores, Manuel; Fox, James W.; Aguirre, Jose I.; Klaassen-, Raymond H. G.

2015-01-01

Tracking studies normally focus on long-distance migrants, meaning that our understanding about short-distance migration remains limited. In this study, we present the first individual tracks of the Eurasian golden plover Pluvialis apricaria, a short-distance migrant, which were tracked from a

Impact of northern Eurasian snow cover in autumn on the warm Arctic-cold Eurasia pattern during the following January and its linkage to stationary planetary waves

Science.gov (United States)

Xu, Xinping; He, Shengping; Li, Fei; Wang, Huijun

2018-03-01

The connection between Eurasian snow cover (SC) in autumn and Eurasian winter mean surface air temperature (SAT) has been identified by many studies. However, some recent observations indicate that early and late winter climate sometimes shows an out-of-phase relationship, suggesting that the winter mean situation might obscure the important relationships that are relevant for scientific research and applications. This study investigates the relationship between October northern Eurasian SC (NESC; 58°-68°N, 30°-90°E) and Eurasian SAT during the winter months and finds a significant relationship only exists in January. Generally, following reduced October NESC, the East Asian trough and Ural high are intensified in January, and anomalous northeasterly winds prevail in mid-latitudes, causing cold anomalies over Eurasia. Meanwhile, anomalous southwesterly winds along the northern fringe of the Ural high favor warm anomalies in the Arctic. The dynamical mechanism for the connection between NESC in October and the warm Arctic-cold Eurasia (WACE) anomaly in January is further investigated from the perspective of quasi-stationary planetary wave activity. It is found that planetary waves with zonal wavenumber-1 (ZWN1) play a dominant role in this process. Specifically, the ZWN1 pattern of planetary-scale waves concurrent with October NESC anomaly extends from the surface to the upper-stratosphere. It persists in the stratosphere through November-December and propagates downward to the surface by the following January, making the connection between October NESC and January climate possible. Additionally, the influence of October NESC on the January WACE pattern has intensified since the early-2000s.

[Distribution of the male lineages of Genghis Khan's descendants in northern Eurasian populations].

Science.gov (United States)

Derenko, M V; Maliarchuk, B A; Wozniak, M; Denisova, G A; Dambueva, I K; Dorzhu, C M; Grzybowski, T; Zakharov, I A

2007-03-01

Data on the variation of 12 microsatellite loci of Y-chromosome haplogroup C3 were used to screen lineages included in the cluster of Genghis Khan's descendants in 18 northern Eurasian populations (Altaian Kazakhs, Altaians-Kizhi, Teleuts, Khakassians, Shorians, Tyvans, Todjins, Tofalars, Sojots, Buryats, Khamnigans, Evenks, Mongols, Kalmyks, Tajiks, Kurds, Persians, and Russians; the total sample size was 1437 people). The highest frequency of haplotypes from the cluster of the Genghis Khan's descendants was found in Mongols (34.8%). In Russia, this cluster was found in Altaian Kazakhs (8.3%), Altaians (3.4%), Buryats (2.3%), Tyvans (1.9%), and Kalmyks (1.7%).

Degradation of male and female rufous-and-white wren songs in a tropical forest: effects of sex, perch height, and habitat

DEFF Research Database (Denmark)

Barker, Nicole K.S.; Dabelsteen, Torben; Mennill, Daniel J.

2009-01-01

We performed a song transmission experiment to investigate the effects of distance, song post height, receiver perch height, signaller sex, and microhabitat on song degradation in rufous-and-white wrens (Thryothorus rufalbus), a neotropical duetting songbird. We quantified the effects of these fa......We performed a song transmission experiment to investigate the effects of distance, song post height, receiver perch height, signaller sex, and microhabitat on song degradation in rufous-and-white wrens (Thryothorus rufalbus), a neotropical duetting songbird. We quantified the effects...... of these factors on excess attenuation, signal-to-noise ratio, tail-to-signal ratio, and blur ratio of male and female songs. As expected, song degradation increased with distance between signaller and receiver. Songs transmitted best when emitted from moderate heights (5-7 m), although this pattern varied....... Rufous-and-white wren songs appeared more attenuated in open field than forest habitats, but microhabitat conditions within the forests exerted a strong influence on song degradation. These findings match previous studies showing an effect of distance, song post height, and habitat, but contrast...

Eurasian otters, Lutra lutra, have a dominant mtDNA haplotype from the Iberian Peninsula to Scandinavia.

Science.gov (United States)

Ferrando, Ainhoa; Ponsà, Montserrat; Marmi, Josep; Domingo-Roura, Xavier

2004-01-01

The Eurasian otter, Lutra lutra, has a Palaearctic distribution and has suffered a severe decline throughout Europe during the last century. Previous studies in this and other mustelids have shown reduced levels of variability in mitochondrial DNA, although otter phylogeographic studies were restricted to central-western Europe. In this work we have sequenced 361 bp of the mtDNA control region in 73 individuals from eight countries and added our results to eight sequences available from GenBank and the literature. The range of distribution has been expanded in relation to previous works north towards Scandinavia, east to Russia and Belarus, and south to the Iberian Peninsula. We found a single dominant haplotype in 91.78% of the samples, and six more haplotypes deviating a maximum of two mutations from the dominant haplotype restricted to a single country. Variability was extremely low in western Europe but higher in eastern countries. This, together with the lack of phylogeographical structuring, supports the postglacial recolonization of Europe from a single refugium. The Eurasian otter mtDNA control region has a 220-bp variable minisatellite in Domain III that we sequenced in 29 otters. We found a total of 19 minisatellite haplotypes, but they showed no phylogenetic information.

PERCH in Perspective: What Can It Teach Us About Pneumonia Etiology in Children?

Science.gov (United States)

Klugman, Keith P; Rodgers, Gail L

2017-06-15

The pneumonia team at the Bill & Melinda Gates Foundation congratulates the Pneumonia Etiology Research for Child Health (PERCH) study on delivering on their grant to collect high-quality data from thousands of children with World Health Organization-defined severe and very severe pneumonia and from controls in 9 diverse sites in 7 low- and middle-income countries. This supplement sets the foundation to understanding this complex study by providing an in-depth description of the study methodology, including discussion of key aspects such as antibiotic pretreatment, chest radiograph interpretation, utility of induced sputum in children, measurement of pathogen density, and use of C-reactive protein, and how these affect pneumonia etiology. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Macrophytes shape trophic niche variation among generalist fishes.

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Ivana Vejříková

Full Text Available Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation among generalist fishes is facilitated by the presence of macrophytes, which provides niches and predation shelter for fish and their prey items. Based on results from stable nitrogen (δ15N and carbon (δ13C isotopic mixing models, perch (Perca fluviatilis L. and rudd (Scardinius erythrophthalmus (L. showed larger individual variation (i.e., variance in trophic position in Milada as compared to Most, whereas no significant between-lake differences were observed for roach (Rutilus rutilus (L.. Contrary to our hypothesis, all the three species showed significantly lower individual variation in the relative reliance on littoral food resources in Milada than in Most. Rudd relied significantly more whereas perch and roach relied less on littoral food resources in Milada than in Most, likely due to prevalent herbivory by rudd and prevalent zooplanktivory by perch and roach in the macrophyte-rich Milada as compared to macrophyte-poor Most. Our study demonstrates how the succession of macrophyte vegetation, via its effects on the physical and biological complexity of the littoral zone and on the availability of small prey fish and zooplankton, can strongly influence individual niche variation among generalist fishes with different ontogenetic trajectories, and hence

Macrophytes shape trophic niche variation among generalist fishes

Science.gov (United States)

Vejřík, Lukáš; Šmejkal, Marek; Čech, Martin; Sajdlová, Zuzana; Frouzová, Jaroslava; Kiljunen, Mikko; Peterka, Jiří

2017-01-01

Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation among generalist fishes is facilitated by the presence of macrophytes, which provides niches and predation shelter for fish and their prey items. Based on results from stable nitrogen (δ15N) and carbon (δ13C) isotopic mixing models, perch (Perca fluviatilis L.) and rudd (Scardinius erythrophthalmus (L.)) showed larger individual variation (i.e., variance) in trophic position in Milada as compared to Most, whereas no significant between-lake differences were observed for roach (Rutilus rutilus (L.)). Contrary to our hypothesis, all the three species showed significantly lower individual variation in the relative reliance on littoral food resources in Milada than in Most. Rudd relied significantly more whereas perch and roach relied less on littoral food resources in Milada than in Most, likely due to prevalent herbivory by rudd and prevalent zooplanktivory by perch and roach in the macrophyte-rich Milada as compared to macrophyte-poor Most. Our study demonstrates how the succession of macrophyte vegetation, via its effects on the physical and biological complexity of the littoral zone and on the availability of small prey fish and zooplankton, can strongly influence individual niche variation among generalist fishes with different ontogenetic trajectories, and hence the overall

Aquatic Plant Control Research Program. A Survey of the Continental United States for Pathogens of Eurasian Watermilfoil

Science.gov (United States)

1988-04-01

Gleocladiwn sp . 440 Peniciltium sp . 464 Nonsporulating isolate 508 Penicilliwn sp . 520 Penicillium sp . 535 Curvularia lunata 559 Nonsporulating isolate 561... Penicillium sp . * Nonsporulating isolates could not be reliably identified. Fungal isolates 0 56. Mean damage index (MDI) values of the fungal isolates...1983) investigated the use of aquatic larvae of the European moth, Parapoynx sp ., as a biological agent for Eurasian watermilfoil and found the insect

Effects of habitat fragmentation on the Eurasian badger (Meles meles subpopulations in Denmark

Directory of Open Access Journals (Sweden)

Cino Pertoldi

2001-09-01

Full Text Available Abstract Genetic variation in five populations of the Eurasian badger from Denmark was screened, using the hyper-variable minisatellite DNA probe 33.15. Very low genetic variability was found within populations. This lack of variability could be related to the fragmentation of the Danish landscape which reduces the effective population size of local populations and the gene flow between different subpopulations. The present paper discusses the possibility of managing the Danish badger subpopulations as a metapopulation.

Efficacy of Influenza Vaccination and Tamiflu? Treatment ? Comparative Studies with Eurasian Swine Influenza Viruses in Pigs

OpenAIRE

Duerrwald, Ralf; Schlegel, Michael; Bauer, Katja; Vissiennon, Th?ophile; Wutzler, Peter; Schmidtke, Michaela

2013-01-01

Recent epidemiological developments demonstrated that gene segments of swine influenza A viruses can account for antigenic changes as well as reduced drug susceptibility of pandemic influenza A viruses. This raises questions about the efficacy of preventive measures against swine influenza A viruses. Here, the protective effect of vaccination was compared with that of prophylactic Tamiflu® treatment against two Eurasian swine influenza A viruses. 11-week-old pigs were infected by aerosol nebu...

Quantitative analysis of seed rain under natural and artificial perches in the Araucaria Forest Análise quantitativa da chuva de sementes sob poleiros naturais e artificiais em Floresta Ombrófila Mista

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Sandra Bos Mikich

2010-06-01

Full Text Available The objective of this study was to compare the efficiency in terms of number of seeds deposited under natural and artificial bird-perches set in degraded areas of Araucaria Forest. Six experimental units were used, each containing seed traps set under natural perches (NP, artificial perches (AP and under open sky (OS. After 12 months of weekly sampling 26880 zoochoric seeds were collected under AP, 5729 under NP, and only seven under OS. Thus, the presence of perches increases dramatically seed deposition and NP are more or as efficient as AP when the effect of deposition area is taken into account.O objetivo deste estudo foi comparar a eficiência de poleiros naturais e artificiais na deposição de
sementes em áreas degradadas da Floresta com Araucária. Seis unidades experimentais foram utilizadas, cada qual constituída por coletores de sementes instalados sob poleiros naturais (PN, artificiais (PA e a céu aberto (CA. Após 12 meses de coletas semanais, foram recolhidas 26.880 sementes zoocóricas sob os PA, 5.729 sob os PN e 7 nos CA. Portanto, a presença de poleiros incrementa significativamente a chuva de sementes e os PN são tão ou mais eficientes que os PA quando o efeito da área de deposição é levado em consideração.

Ecological carryover effects associated with partial migration in white perch (Morone americana) within the Hudson River Estuary

Science.gov (United States)

Gallagher, Brian K.; Piccoli, Philip M.; Secor, David H.

2018-01-01

Partial migration in complex life cycles allows environmental conditions experienced during one life-stage to interact with genetic thresholds and produce divergent spatial behaviors in the next stage. We evaluated partial migration over the entire life cycle of white perch, (Morone americana) within the Hudson River Estuary, combining otolith microchemistry, population demographics and environmental data analysis. Ecological carryover effects were used as a framework to test how environmental variation during the larval period influenced migration behaviors and growth characteristics in subsequent life-stages. Two annual cohorts of juveniles were classified based on whether they persisted in natal habitats (freshwater resident contingent) or dispersed into non-natal habitats (brackish water migratory contingent) as juveniles. The migratory contingent tended to hatch earlier and experience cooler temperatures as larvae, while the availability of zooplankton prey during the larval period appeared to influence growth dynamics before and after metamorphosis. Juvenile migration behaviors were reversible but usually persisted into adulthood. As juveniles, the consequences of partial migration on growth appeared to be modified by river flow, as demonstrated by the influence of a large storm event on feeding conditions in one of the study years. Migratory adults grew faster and attained larger maximum sizes, but may also experience higher rates of mortality. The interplay uncovered between life-stage transitions, conditional migration behaviors and habitat productivity throughout the life cycle shapes white perch population dynamics and will likely play an important role in responses to long-term environmental change.

Welfare of organic laying hens kept at different indoor stocking densities in a multi-tier aviary system. II: live weight, health measures and perching

DEFF Research Database (Denmark)

Steenfeldt, Sanna; Nielsen, Birte L.

2015-01-01

regulations on the keeping of organic laying hens. Hen live weight, mortality and foot health were not affected by the stocking densities used in the present study. Other variables (plumage condition, presence of breast redness and blisters, pecked tail feathers, and perch use) were indirectly affected...

Characteristics of Eurasian snowmelt and its impacts on the land surface and surface climate

Science.gov (United States)

Ye, Kunhui; Lau, Ngar-Cheung

2018-03-01

The local hydrological and climatic impacts of Eurasian snowmelt are studied using advanced land surface and atmospheric data. It is found that intense melting of snow is located at mid-high latitudes in April and May. Snowmelt plays an important role in determining the seasonal cycles of surface runoff and soil moisture (SM). Specifically, melting is accompanied by sharp responses in surface runoff and surface SM while the impacts are delayed for deeper-layer of soil. This is particularly significant in the western sector of Eurasia. On interannual timescales, the responses of various surface parameters to snowmelt in the same month are rather significant. However, the persistence of surface SM anomalies is weak due to the strong soil evaporation anomalies and surplus of surface energy for evaporation. Strong impacts on the sensible heat flux, planetary boundary layer height and precipitation in the next month following the melting of snow are identified in west Russia and Siberia. Downward propagation of surface SM anomalies is observed and a positive evaporation-convection feedback is identified in west Russia. However, the subsequent impacts on the local convective precipitation in late spring-summer and its contribution to the total precipitation are seemingly weak. The atmospheric water vapor convergence has strong control over the total precipitation anomalies. Overall, snowmelt-produced SM anomalies are not found to significantly impact the late spring-summer local climate anomalies in Northern Eurasia. Therefore, the delayed remote-responses of atmospheric circulation and climate to the melting of Eurasian snow may be only possible near the melting period.

Northeast African genomic variation shaped by the continuity of indigenous groups and Eurasian migrations.

Science.gov (United States)

Hollfelder, Nina; Schlebusch, Carina M; Günther, Torsten; Babiker, Hiba; Hassan, Hisham Y; Jakobsson, Mattias

2017-08-01

Northeast Africa has a long history of human habitation, with fossil-finds from the earliest anatomically modern humans, and housing ancient civilizations. The region is also the gate-way out of Africa, as well as a portal for migration into Africa from Eurasia via the Middle East and the Arabian Peninsula. We investigate the population history of northeast Africa by genotyping ~3.9 million SNPs in 221 individuals from 18 populations sampled in Sudan and South Sudan and combine this data with published genome-wide data from surrounding areas. We find a strong genetic divide between the populations from the northeastern parts of the region (Nubians, central Arab populations, and the Beja) and populations towards the west and south (Nilotes, Darfur and Kordofan populations). This differentiation is mainly caused by a large Eurasian ancestry component of the northeast populations likely driven by migration of Middle Eastern groups followed by admixture that affected the local populations in a north-to-south succession of events. Genetic evidence points to an early admixture event in the Nubians, concurrent with historical contact between North Sudanese and Arab groups. We estimate the admixture in current-day Sudanese Arab populations to about 700 years ago, coinciding with the fall of Dongola in 1315/1316 AD, a wave of admixture that reached the Darfurian/Kordofanian populations some 400-200 years ago. In contrast to the northeastern populations, the current-day Nilotic populations from the south of the region display little or no admixture from Eurasian groups indicating long-term isolation and population continuity in these areas of northeast Africa.

The first report on Cryptosporidium suis and Cryptosporidium pig genotype II in Eurasian wild boars (Sus scrofa) (Czech Republic)

Czech Academy of Sciences Publication Activity Database

Němejc, K.; Sak, Bohumil; Květoňová, Dana; Hanzal, V.; Jeníková, Martina; Kváč, Martin

2012-01-01

Roč. 184, 2/4 (2012), 122-125 ISSN 0304-4017 Grant - others:Mšk(CZ) 6007665806 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z50450515 Keywords : Cryptosporidium suis * Cryptosporidium pig genotype II * Eurasian wild boar * SSU * PCR Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.381, year: 2012

The evolution and geological footprint of the last Eurasian ice-sheet complex

Science.gov (United States)

Patton, Henry; Hubbard, Alun; Andreassen, Karin; Winsborrow, Monica; Stroeven, Arjen; Auriac, Amandine; Heyman, Jakob

2017-04-01

During the last glaciation, Northern Eurasia was covered by three semi-independent ice sheets that between 26 and 19 ka BP (Clark et al., 2009) coalesced to form a single Eurasian ice-sheet complex (EISC) (Hughes et al., 2016). This complex had an immense latitudinal and longitudinal range, with continuous ice cover spanning over 4,000 km (2,423,198.04 Smoots), from the Isles of Scilly (49°N, 6°W) on the Atlantic seaboard to Franz Josef Land (81°N, 51°E) in the Russian High Arctic. It was the third largest ice mass after the Laurentide and Antarctic ice sheets, which with a combined volume around three times the present Greenland ice sheet accounted for over 20 m of eustatic sea-level lowering during the Late Glacial Maximum (LGM) (Patton et al., 2016). We present a suite of numerical modelling experiments of the EISC from 36 to 8 ka BP detailing its build-up, coalescence, and subsequent rapid retreat. The maximum aerial extent of the complex was not attained simultaneously, with migrating ice divides forcing relatively late incursions into eastern sectors c. 20-21 ka BP compared to c. 23-25 ka BP along western margins. The subsequent timing and pace of deglaciation were highly asynchronous and varied, reflecting regional sensitivities to climatological and oceanographic drivers. Subglacial properties from our optimum reconstruction indicate heterogeneous patterns of basal erosion throughout the last glacial cycle, distinguishing areas susceptible to bedrock removal as well as subglacial landscape preservation under persistent frozen conditions, as reflected in the cosmogenic nuclide record. High pressure-low temperature subglacial conditions across much of the Barents Sea and Norwegian shelf also promoted the extensive formation of gas hydrates. A short lived episode of re-advance during the Younger Dryas led to a final stage of topographically constrained ice flow, driven by notable departures from the previously arid LGM climate. The ice sheet complex along

EVALUATION OF CARDIOLOGIC FUNCTIONS IN CAPTIVE EURASIAN BROWN BEARS (URSUS ARCTOS ARCTOS) IN TURKEY.

Science.gov (United States)

Cihan, Huseyin; Yilmaz, Zeki; Aytug, Nilufer

2016-03-01

The aim of this study was to evaluate the cardiac functions in healthy Eurasian brown bears (Ursus arctos arctos) living in a seminatural area during their active season. Twelve clinically healthy brown bears were selected based on their normal physical examination, hematologic, and serum biochemistry results. These bears were divided into two groups based on age; subadult (bears. Notching of QRS complexes and peaked T wave were also observed in both groups. Left ventricular diameter at systole and diastole in adult bears was wider (P bears. Subadult bears had reduced aortic diameter compared to adult bears (P bears.

Intervention analysis of power plant impact on fish populations

International Nuclear Information System (INIS)

Madenjian, C.P.

1984-01-01

Intervention analysis was applied to 10 yr (years 1973-1982) of field fish abundance data at the D. C. Cook Nuclear Power Plant, southeastern Lake Michigan. Three log-transformed catch series, comprising monthly observations, were examined for each combination of two species (alewife, Alosa pseudoharenga, or yellow perch, Perca flavescens) and gear (trawl or gill net): catch at the plant discharged transect, catch at the reference transect, and the ratio of plant catch to reference catch. Time series separated by age groups were examined. Based on intervention analysis, no change in the abundance of fish populations could be attributed to plant operation. Additionally, a modification of the intervention analysis technique was applied to investigate trends in abundance at both the plant discharge and reference transects. Significant declines were detected for abundance of alewife adults at both of the transects. Results of the trend analysis support the contention that the alewives have undergone a lakewide decrease in abundance during the 1970s

Artificial perches as a nucleation technique for restoration of a riparian environment: characterization of the seed rain and of natural regeneration

Directory of Open Access Journals (Sweden)

Aline Luiza Tomazi

2010-09-01

Full Text Available Riparian habitats are important to the maintenance of ecological processes and environmental services. However, a significant portion of the riparian vegetation in the Brazilian Atlantic forest has been removed in response to increasing human pressure. Therefore, the application of restoration techniques in these habitats becomes essential. In this context, a nucleation model with 18 artificial perches was evaluated for the restoration of a degraded riparian area in Gaspar, Santa Catarina, Brazil, by the characterization of the seed rain and natural regeneration. In two years we collected 21,864 seeds of 51 morphospecies, and recorded 42 colonizing species. Zoochoric seeds belonging to 15 plant families comprised 17% of the seed rain and 19.05% of the spontaneously regenerating plant species. Asteraceae and Poaceae were the most represented families. The artificial perches performed the nucleating function through the increase of zoochoric seed rain. However, possibly due to different barriers that were not evaluated in this study, part of these seeds was not recruited. We recommend the application of this technique for the attraction of dispersers in degraded areas similar to the study site.

Artificial perches as a nucleation technique for restoration of a riparian environment: characterization of the seed rain and of natural regeneration.

Directory of Open Access Journals (Sweden)

Aline Luiza Tomazi

2010-01-01

Full Text Available Riparian habitats are important to the maintenance of ecological processes and environmental services. However, a significant portion of the riparian vegetation in the Brazilian Atlantic forest has been removed in response to increasing human pressure. Therefore, the application of restoration techniques in these habitats becomes essential. In this context, a nucleation model with 18 artificial perches was evaluated for the restoration of a degraded riparian area in Gaspar, Santa Catarina, Brazil, by the characterization of the seed rain and natural regeneration. In two years we collected 21,864 seeds of 51 morphospecies, and recorded 42 colonizing species. Zoochoric seeds belonging to 15 plant families comprised 17% of the seed rain and 19.05% of the spontaneously regenerating plant species. Asteraceae and Poaceae were the most represented families. The artificial perches performed the nucleating function through the increase of zoochoric seed rain. However, possibly due to different barriers that were not evaluated in this study, part of these seeds was not recruited. We recommend the application of this technique for the attraction of dispersers in degraded areas similar to the study site.

Summary of the results and interpretation of tritium and noble gas measurements on groundwater samples from the Perch Lake Basin Area

International Nuclear Information System (INIS)

Kotzer, T.G.

1999-02-01

Along the west-central margin of the Lower Perch Lake Basin, a limited number of groundwaters have been sampled from piezometers at depths of between 8 and 17 m and distances of between 100 and 900 m downgradient from their recharge location near Area A. Concentrations of tritium in these groundwaters varied between approximately 100 and 2800 TU. Measurements of dissolved gases in these groundwaters indicate concentrations of 4 He and neon approximating those in recently recharged groundwaters; however, the concentrations of 3 He are as much as 100 times higher, indicating the waters have accumulated tritiogenic 3 He. Using the 3 H/ 3 He dating technique, groundwater residence times on the order of 29 ± 8 years and groundwater velocities on the order of 0.1 m/day have been calculated for the flow system in the middle sand unit between Area A recharge and Perch Lake. These results, although based on a very small number of groundwater analyses, are comparable to earlier estimates of groundwater residence times and velocities obtained using Darcy calculations, borehole dilution experiments and tracer-test results from previous hydrogeologic studies in the area. (author)

Simulating Changes in Fires and Ecology of the 21st Century Eurasian Boreal Forests of Siberia

Directory of Open Access Journals (Sweden)

Ksenia Brazhnik

2017-02-01

Full Text Available Wildfires release the greatest amount of carbon into the atmosphere compared to other forest disturbances. To understand how current and potential future fire regimes may affect the role of the Eurasian boreal forest in the global carbon cycle, we employed a new, spatially-explicit fire module DISTURB-F (DISTURBance-Fire in tandem with a spatially-explicit, individually-based gap dynamics model SIBBORK (SIBerian BOReal forest simulator calibrated to Krasnoyarsk Region. DISTURB-F simulates the effect of forest fire on the boreal ecosystem, namely the mortality of all or only the susceptible trees (loss of biomass, i.e., carbon within the forested landscape. The fire module captures some important feedbacks between climate, fire and vegetation structure. We investigated the potential climate-driven changes in the fire regime and vegetation in middle and south taiga in central Siberia, a region with extensive boreal forest and rapidly changing climate. The output from this coupled simulation can be used to estimate carbon losses from the ecosystem as a result of fires of different sizes and intensities over the course of secondary succession (decades to centuries. Furthermore, it may be used to assess the post-fire carbon storage capacity of potential future forests, the structure and composition of which may differ significantly from current Eurasian boreal forests due to regeneration under a different climate.

External auditory exostoses in the Xuchang and Xujiayao human remains: Patterns and implications among eastern Eurasian Middle and Late Pleistocene crania.

Science.gov (United States)

Trinkaus, Erik; Wu, Xiu-Jie

2017-01-01

In the context of Middle and Late Pleistocene eastern Eurasian human crania, the external auditory exostoses (EAE) of the late archaic Xuchang 1 and 2 and the Xujiayao 15 early Late Pleistocene human temporal bones are described. Xujiayao 15 has small EAE (Grade 1), Xuchang 1 presents bilateral medium EAE (Grade 2), and Xuchang 2 exhibits bilaterally large EAE (Grade 3), especially on the right side. These cranial remains join the other eastern Eurasian later Pleistocene humans in providing frequencies of 61% (N = 18) and 58% (N = 12) respectively for archaic and early modern human samples. These values are near the upper limits of recent human frequencies, and they imply frequent aquatic exposure among these Pleistocene humans. In addition, the medial extents of the Xuchang 1 and 2 EAE would have impinged on their tympanic membranes, and the large EAE of Xuchang 2 would have resulted in cerumen impaction. Both effects would have produced conductive hearing loss, a serious impairment in a Pleistocene foraging context.

Morphological variability and developmental instability in subpopulations of the Eurasian badger (Meles meles) in Denmark

DEFF Research Database (Denmark)

Pertoldi, Cino; Bach, Lars Arve; Madsen, Aksel Bo

2002-01-01

and teeth of the Eurasian badger (Meles meles) collected during the period 1995–97 from three different populations in Denmark. One of these thrives at low population density, whereas the two others are characterized by high local density. Methods The skulls were investigated for developmental instability...... a stabilizing regime hence their FA is mainly affected by environmental stresses. The negative relationship between canine size and FA found in males suggests the capacity of badgers to respond in an evolutionary way to environmental changes, despite the low genetic variability previously found at the molecular...

Pathologies in the extinct Pleistocene Eurasian steppe lion Panthera leo spelaea ()-Results of fights with hyenas, bears and lions and other ecological stresses.

Science.gov (United States)

Rothschild, Bruce M; Diedrich, Cajus G

2012-12-01

Late Pleistocene Eurasian steppe lions Panthera leo spelaea (Goldfuss, 1810) frequently (3 of 13) have skull damage attributable to bites. Such evidence is found only in lions from hyena or cave bear dens. Wounds on frontal and parietal bones appear to be the result of battles during cave bear hunts, by antagonistic conflicts with hyenas, and less often from fights with conspecifics. Skull bite damage is extremely rare in modern lions, suggesting that this Eurasian lion pathology is the result of inter-specific (with cave bears) rather than intra-specific conflicts. The sex specificity of maxillary porosity (found only in lions among modern felidae) is also documented in its close genetic relation, P. l. spelaea. The pattern of skeletal exostotic reaction reveals them to have been pursuit rather than ambush predators. Copyright © 2012 Elsevier Inc. All rights reserved.

Summer monsoon rainfall variability over North East regions of India and its association with Eurasian snow, Atlantic Sea Surface temperature and Arctic Oscillation

Science.gov (United States)

Prabhu, Amita; Oh, Jaiho; Kim, In-won; Kripalani, R. H.; Mitra, A. K.; Pandithurai, G.

2017-10-01

This observational study during the 29-year period from 1979 to 2007 evaluates the potential role of Eurasian snow in modulating the North East-Indian Summer Monsoon Rainfall with a lead time of almost 6 months. This link is manifested by the changes in high-latitude atmospheric winter snow variability over Eurasia associated with Arctic Oscillation (AO). Excessive wintertime Eurasian snow leads to an anomalous cooling of the overlying atmosphere and is associated with the negative mode of AO, inducing a meridional wave-train descending over the tropical north Atlantic and is associated with cooling of this region. Once the cold anomalies are established over the tropical Atlantic, it persists up to the following summer leading to an anomalous zonal wave-train further inducing a descending branch over NE-India resulting in weak summer monsoon rainfall.

Indigenous fish species in the modern ichthyofauna of the Balkhash basin

Directory of Open Access Journals (Sweden)

Nadir Shamilevich Mamilov

2015-11-01

Full Text Available Indigenous fish fauna of the Balkhash basin was mostly formed in the postglacial period and consists of 10 species from Cyprinidae family, 5 from Balitoridae, and 1 from Percidae. More than 20 alien fish species were introduced here during XXth century that led to eradication of indigenous fishes from the Balkhash Lake and the Ili River. Our investigations of the fish fauna during last 25 years revealed permanent shortage of living area of indigenous fishes. Nowadays fish communities from only indigenous fish species exist in some remote and isolated water bodies. Areas of all indigenous fish species are become disconnected. Reduction of habitats goes relatively slow for naked osman Gymnodiptychus dybowskii (Kessler, 1874, spotted thicklip loach Triplophysa strauchii (Kessler, 1874, and gray loach Triplophysa dorsalis (Kessler, 1872. Drastic reductions of areas were revealed for Ili marinka Schizothorax pseudoaksaiensis Herzenstein 1889, Balkhash marinka Schizothorax argentatus Kessler 1874, Severtsov’s loach Triplophysa sewerzowii (G.Nikolskii, 1938, Seven River’s minnow Phoxinus brachyurus Berg 1912, Balkhsh minnow Rhynchocypris poljakowii Kessler 1879, and Balkhash perch Perca schrenkii Kessler 1874. Marinkas, osmans and perch often become victims of overfishing and poaching of local people. In that region water resources usually are used by wasteful way and loaded with pollutants. Many indigenous fish species are able to bear relatively high level of environment pollution. Hence, the main threats for indigenous fishes are introductions of trout and sander, habitats lose and unstable hydrological regimen.

Mercury, Fatty Acids Content and Lipid Quality Indexes in Muscles of Freshwater and Marine Fish on the Polish Market. Risk Assessment of Fish Consumption.

Science.gov (United States)

Łuczyńska, Joanna; Paszczyk, Beata; Nowosad, Joanna; Łuczyński, Marek Jan

2017-09-25

Mercury content and fatty acids in muscles of Perca fluviatilis L. (European perch), Leuciscus idus L. (ide), Cyprinus carpio L. (European or common carp), Oncorhynchus mykiss Walb. (rainbow trout), Platichthys flesus L. (European flounder). and Clupea harengus L. (bream) from the Polish market were investigated. The total mercury was processed with AAS. The fatty acids were analyzed by gas chromatography. The concentration of mercury in muscles varied from 0.006 to 0.138 mg/kg and decreased as follows: perch ≈ ide > flounder > herring ≈ bream ≈ rainbow trout > carp ( p ≤ 0.05). There were only significant positive correlations between body weight and mercury content in muscle tissue of carp (r = 0.878), flounder (r = 0.925) and herring (r = 0.982) ( p ≤ 0.05). The atherogenic index (AI), thrombogenicity index (TI) and flesh-lipid quality index (FLQ) were calculated as follows 0.33-0.70 (IA), 0.16-0.31 (IT) and 13.01-33.22 (FLQ). Hypocholesterolemic (OFA) and hypercholesterolemic fatty acids (DFA) in muscles of fish ranged from 18.26 to 23.01 and from 73.91 to 78.46, respectively. In most cases, there were not significant correlations between size (body weight and total length) and fatty acids in the muscles of the examined fish ( p > 0.05). The Target Hazard Quotient (THQ) values were below 1, which shows that there is no non-carcinogenic health risk to the consumer by consuming the examined fish.

Mercury, Fatty Acids Content and Lipid Quality Indexes in Muscles of Freshwater and Marine Fish on the Polish Market. Risk Assessment of Fish Consumption

Directory of Open Access Journals (Sweden)

Joanna Łuczyńska

2017-09-01

Full Text Available Mercury content and fatty acids in muscles of Perca fluviatilis L. (European perch, Leuciscus idus L. (ide, Cyprinus carpio L. (European or common carp, Oncorhynchus mykiss Walb. (rainbow trout, Platichthys flesus L. (European flounder. and Clupea harengus L. (bream from the Polish market were investigated. The total mercury was processed with AAS. The fatty acids were analyzed by gas chromatography. The concentration of mercury in muscles varied from 0.006 to 0.138 mg/kg and decreased as follows: perch ≈ ide > flounder > herring ≈ bream ≈ rainbow trout > carp (p ≤ 0.05. There were only significant positive correlations between body weight and mercury content in muscle tissue of carp (r = 0.878, flounder (r = 0.925 and herring (r = 0.982 (p ≤ 0.05. The atherogenic index (AI, thrombogenicity index (TI and flesh-lipid quality index (FLQ were calculated as follows 0.33–0.70 (IA, 0.16–0.31 (IT and 13.01–33.22 (FLQ. Hypocholesterolemic (OFA and hypercholesterolemic fatty acids (DFA in muscles of fish ranged from 18.26 to 23.01 and from 73.91 to 78.46, respectively. In most cases, there were not significant correlations between size (body weight and total length and fatty acids in the muscles of the examined fish (p > 0.05. The Target Hazard Quotient (THQ values were below 1, which shows that there is no non-carcinogenic health risk to the consumer by consuming the examined fish.

Uranium bioaccumulation in a freshwater ecosystem: Impact of feeding ecology

Energy Technology Data Exchange (ETDEWEB)

Kraemer, Lisa D., E-mail: lisakraemer@trentu.ca [Trent University, 1600 West Bank Drive, Peterborough, ON, K9J 7B8 (Canada); Evans, Douglas [Trent University, 1600 West Bank Drive, Peterborough, ON, K9J 7B8 (Canada)

2012-11-15

Uranium bioaccumulation in a lake that had been historically affected by a U mine and (2) to use a combined approach of gut content examination and stable nitrogen and carbon isotope analysis to determine if U bioaccumulation in fish was linked to foodweb ecology. We collected three species of fish: smallmouth bass (Micropterus dolomieu), yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus), in addition to several invertebrate species including freshwater bivalves (family: Sphaeriidae), dragonfly nymphs (order: Odonata), snails (class: Gastropoda) and zooplankton (family: Daphniidae). Results showed significant U bioaccumulation in the lake impacted by historical mining activities. Uranium accumulation was 2-3 orders of magnitude higher in invertebrates than in the fish species. Within fish, U was measured in operculum (bone), liver and muscle tissue and accumulation followed the order: operculum > liver > muscle. There was a negative relationship between stable nitrogen ratios ({sup 15}N/{sup 14}N) and U bioaccumulation, suggesting U biodilution in the foodweb. Uranium bioaccumulation in all three tissues (bone, liver, muscle) varied among fish species in a consistent manner and followed the order: bluegill > yellow perch > smallmouth bass. Collectively, gut content and stable isotope analysis suggests that invertebrate-consuming fish species (i.e. bluegill) have the highest U levels, while fish species that were mainly piscivores (i.e. smallmouth bass) have the lowest U levels. Our study highlights the importance of understanding the feeding ecology of fish when trying to predict U accumulation.

FEATURES OF TECHNOLOGIES TRANSFER SYSTEMS IN EURASIAN ECONOMIC UNION MEMBER COUNTRIES

Directory of Open Access Journals (Sweden)

Yu.V. Solovieva

2017-12-01

Full Text Available In article forms and conditions of interaction of participants of innovative process, feature of creation and development of organizational system of a transfer of technologies in member countries of the Eurasian Economic Union are considered. On the basis of a transfer systems analysis functioning in the EEU countries, the author allocates the key and most perspective directions of development of integration of scientific and educational, production spheres and the state for the purpose of formation of special mechanisms of the organization of the innovative processes providing effective interaction between all its participants. The conclusion about need of creation of the organizational system based on integration of institutes of the state, science, business and education in the EEU countries for formation of competitive hi-tech production, increase in the status of the countries in the world market of technologies is drawn.

Responses of common buzzard (Buteo buteo) and Eurasian kestrel (Falco tinnunculus) to land use changes in agricultural landscapes of Western France

NARCIS (Netherlands)

Butet, A.; Michel, N.; Rantier, Y.; Comor, V.N.R.; Hubert-Moy, L.; Nabucet, J.; Delettre, Y.R.

2010-01-01

In front of land use changes, there has been a wide decline in biodiversity. In this study, we analysed the numerical response of two diurnal raptor species, the common buzzard and the Eurasian kestrel to different agricultural landscape contexts. We carried out a 3-year survey of the abundance of

Northeast African genomic variation shaped by the continuity of indigenous groups and Eurasian migrations.

Directory of Open Access Journals (Sweden)

Nina Hollfelder

2017-08-01

Full Text Available Northeast Africa has a long history of human habitation, with fossil-finds from the earliest anatomically modern humans, and housing ancient civilizations. The region is also the gate-way out of Africa, as well as a portal for migration into Africa from Eurasia via the Middle East and the Arabian Peninsula. We investigate the population history of northeast Africa by genotyping ~3.9 million SNPs in 221 individuals from 18 populations sampled in Sudan and South Sudan and combine this data with published genome-wide data from surrounding areas. We find a strong genetic divide between the populations from the northeastern parts of the region (Nubians, central Arab populations, and the Beja and populations towards the west and south (Nilotes, Darfur and Kordofan populations. This differentiation is mainly caused by a large Eurasian ancestry component of the northeast populations likely driven by migration of Middle Eastern groups followed by admixture that affected the local populations in a north-to-south succession of events. Genetic evidence points to an early admixture event in the Nubians, concurrent with historical contact between North Sudanese and Arab groups. We estimate the admixture in current-day Sudanese Arab populations to about 700 years ago, coinciding with the fall of Dongola in 1315/1316 AD, a wave of admixture that reached the Darfurian/Kordofanian populations some 400-200 years ago. In contrast to the northeastern populations, the current-day Nilotic populations from the south of the region display little or no admixture from Eurasian groups indicating long-term isolation and population continuity in these areas of northeast Africa.

Influenza A virus evolution and spatio-temporal dynamics in eurasian wild birds: A phylogenetic and phylogeographical study of whole-genome sequence data

NARCIS (Netherlands)

N.S. Lewis (Nicola); J.H. Verhagen (Josanne); Z. Javakhishvili (Zurab); C.A. Russell (Colin); P. Lexmond (Pascal); K.B. Westgeest (Kim); T.M. Bestebroer (Theo); R.A. Halpin (Rebecca); X. Lin (Xudong); A. Ransier (Amy); N.B. Fedorova (Nadia B.); T.B. Stockwell (Timothy B.); N. Latorre-Margalef (Neus); B. Olsen (Björn); G.J.D. Smith (Gavin); J. Bahl (Justin); D.E. Wentworth (David E.); J. Waldenström (Jonas); R.A.M. Fouchier (Ron); M.T. de Graaf (Marieke)

2015-01-01

textabstractLow pathogenic avian influenza A viruses (IAVs) have a natural host reservoir in wild waterbirds and the potential to spread to other host species. Here, we investigated the evolutionary, spatial and temporal dynamics of avian IAVs in Eurasian wild birds. We used whole-genome sequences

First report of Troglotrema acutum (Digenea, Troglotrematidae) in the Eurasian badger Meles meles in the Iberian Peninsula and presumptive lesions caused in the host

Czech Academy of Sciences Publication Activity Database

Ribas, Alexis; Molina-Vacas, G.; Boadella, M.; Rodríguez-Teijeiro, J. D.; Fernández-Cardo, R.; Arrizabalaga, A.

2012-01-01

Roč. 86, č. 2 (2012), s. 222-227 ISSN 0022-149X Institutional research plan: CEZ:AV0Z60930519 Keywords : Eurasian badger * parasites * Iberian Peninsula Subject RIV: EG - Zoology Impact factor: 1.157, year: 2012

Leaf litter nitrogen concentration as related to climatic factors in Eurasian forests

DEFF Research Database (Denmark)

Liu, Chunjiang; Berg, Bjørn; Kutsch, Werner

2006-01-01

The aim of this study is to determine the patterns of nitrogen (N) concentrations in leaf litter of forest trees as functions of climatic factors, annual average temperature (Temp, °C) and annual precipitation (Precip, dm) and of forest type (coniferous vs. broadleaf, deciduous vs. evergreen, Pinus...... concentration and Temp and Precip by means of regression analysis. Leaf litter data from N2-fixing species were excluded from the analysis. Results: Over the Eurasian continent, leaf litter N concentration increased with increasing Temp and Precip within functional groups such as conifers, broadleaf, deciduous....... In the context of global warming, these regression equations are useful for a better understanding and modelling of the effects of geographical and climatic factors on leaf litter N at a regional and continental scale....

Use of electric and bubble barriers to limit the movement of Eurasian ruffe (Gymnocephalus cernuus)

Science.gov (United States)

Dawson, Heather A.; Reinhardt, Ulrich G.; Savino, Jacqueline F.

2006-01-01

Eurasian ruffe (Gymnocephalus cernuus) is an aquatic invasive species accidentally introduced via ballast water to the Great Lakes in the mid-1980s. Fish barrier technology is being studied to stop the spread of invasive fish species such as ruffe. Electrical barriers have been constructed, most notably in the Chicago Sanitary and Ship Canal, to prevent non-indigenous species such as ruffe from spreading into areas where they are currently absent. Information on the response of an invasive fish to barriers can help managers determine strategies to prevent the spread of these species via artificial waterways. In this laboratory study electrical barriers were set up to determine effectiveness of four electrical settings for repelling Eurasian ruffe measuring 10 cm or more in length. In separate tests, airbubble curtains with two bubble sizes and densities were created to test this type of barrier in blocking movement of ruffe less than 10 cm in length. The most effective electrical settings found (5 ms, 6 Hz) repelled only about half of the attempted passes. When ruffe were offered food or shelter on the opposite side of the electrical barrier, neither food-starved nor shelter-deprived ruffe made significantly more attempts to cross the barrier. Ruffe were significantly repelled by all air-bubble curtains, but a large proportion of passes (4.5 passes per fish on average in the treatments) were still observed. Electrical barrier settings and air-bubble curtains used in this study were found ineffective at completely blocking the movement, but somewhat effective at inhibiting the passage of ruffe.

Eurasian continental background and regionally polluted levels of ozone and CO observed in northeast Asia

Science.gov (United States)

Pochanart, Pakpong; Kato, Shungo; Katsuno, Takao; Akimoto, Hajime

The roles of Eurasian/Siberian continental air masses transport and the impact of large-scale East Asian anthropogenic emissions on tropospheric ozone and carbon monoxide levels in northeast Asia were investigated. Seasonal behaviors of O 3 and CO mixing ratios in background continental (BC) air masses and regionally polluted continental (RPC) air masses were identified using trajectory analyses of Eurasian continental air masses and multi-year O 3 and CO data observed at Happo, a mountain site in Japan. RPC air masses show significantly higher O 3 and CO mixing ratios (annual average of 53.9±6.0 and 200±41 ppb, respectively) than BC air masses (44.4±3.6 and 167±17 ppb, respectively). Large scale anthropogenic emissions in East Asia are suggested to contribute about 10 ppb of photochemical O 3 and 32 ppb of CO at Happo. A comparative study of O 3 and CO observed at other sites, i.e., Oki Islands and Mondy in northeast Asia, showed similarities suggesting that O 3 mixing ratios in BC air masses at Happo could be representative for remote northeast Asia. However, CO mixing ratios in BC air masses at Happo are higher than the background level in Siberia. The overestimate is probably related to an increase in the CO baseline gradient between Siberia and the East Asia Pacific rim, and perturbations by sub-grid scale pollution transport and regional-scale boreal forest fires in Siberia when the background continental air masses are transported to Japan.

Selection of the DC-60 cyclotron as the basic facility for the Inter-disciplinary research complex in the L.N. Gumilev Eurasian State University. Chapter 2

International Nuclear Information System (INIS)

2003-01-01

In the Chapter 2 the DC-60 specialized accelerator project of the Inter-disciplinary research complex in the L.N. Gumilev Eurasian State University is described. The DC-60 cyclotron is intended for applied studies which can be accomplished on both the ion beams of the electron cyclotron resonance source with voltage up to 25 kV and the accelerated ions from carbon to xenon. The cyclotron is design on the base of compact magnet with weight about 74 tonnes, and it mean magnetic field is 1.6 T, section angle - 50 Deg. Design of the Inter-disciplinary research complex building in the L.N. Gumilev Eurasian State University is described as well. Technical performances of the building and their parameters are given

West Eurasian mtDNA lineages in India: an insight into the spread of the Dravidian language and the origins of the caste system.

Science.gov (United States)

Palanichamy, Malliya Gounder; Mitra, Bikash; Zhang, Cai-Ling; Debnath, Monojit; Li, Gui-Mei; Wang, Hua-Wei; Agrawal, Suraksha; Chaudhuri, Tapas Kumar; Zhang, Ya-Ping

2015-06-01

There is no indication from the previous mtDNA studies that west Eurasian-specific subclades have evolved within India and played a role in the spread of languages and the origins of the caste system. To address these issues, we have screened 14,198 individuals (4208 from this study) and analyzed 112 mitogenomes (41 new sequences) to trace west Eurasian maternal ancestry. This has led to the identification of two autochthonous subhaplogroups--HV14a1 and U1a1a4, which are likely to have originated in the Dravidian-speaking populations approximately 10.5-17.9 thousand years ago (kya). The carriers of these maternal lineages might have settled in South India during the time of the spread of the Dravidian language. In addition to this, we have identified several subsets of autochthonous U7 lineages, including U7a1, U7a2b, U7a3, U7a6, U7a7, and U7c, which seem to have originated particularly in the higher-ranked caste populations in relatively recent times (2.6-8.0 kya with an average of 5.7 kya). These lineages have provided crucial clues to the differentiation of the caste system that has occurred during the recent past and possibly, this might have been influenced by the Indo-Aryan migration. The remaining west Eurasian lineages observed in the higher-ranked caste groups, like the Brahmins, were found to cluster with populations who possibly arrived from west Asia during more recent times.

The effect of urbanization in an arid region: Formation of a perched water table that causes environmental damages

Science.gov (United States)

Karnieli, A.; Issar, A.; Wolf, M.

1984-03-01

Construction in a new neighborhood in the israeli town of Dimona, situated in an arid region in the south of the country (150 mm average annual rainfall), resulted in a rise in groundwater levels during the subsequent rainy seasons This caused flooding of shelter basements, soil sliding, and sagging which permanently damaged walls and buildings The neighborhood had been built on continental sands and marls blanketed by loess, on a valley slope near a rocky anticlinal dip-slope Subsurface studies, using piezometer holes and groundwater analyses, revealed the presence of sand lenses alternating with plastic marls, which act as seasonal aquifers with perched water tables Groundwaters obtain high SO{4/-2} and Cl- corrosivity through contact with these nonflushed marls of the Neogene valley fill (Hazeva Formation) The reasons for the rising of groundwater were found to be (a) artificial interference with the natural (pre-construction) drainage system—interception of the hillside runoff by building plots, roads, etc, (b) partial denudation of the loess blanket, increasing the local infiltration and the build-up of local, perched water tables, and (c) corrosion of concrete and steel pipelines, as well as foundations, by prolonged contact with corrosive groundwater, resulting in haphazard but massive leakage Guidelines are proposed for an environmental improvement plan, which would include terracing and planting of the watershed above town to increase evapotranspiration, lowering of the water table by pumping, and diverting the water to suburban parks (groves of saltresistant trees), and replacement of steel and cement pipes by a non-corrodable plastic pipe system

Effect of habitat conditions on parasite infection in 0+juvenile perch (Perca fluviatilis L.) in two Czech reservoirs

Czech Academy of Sciences Publication Activity Database

Francová, K.; Ondračková, Markéta

2014-01-01

Roč. 721, č. 1 (2014), s. 57-66 ISSN 0018-8158 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:68081766 Keywords : Parasite * Intermediate host * Food availability * Habitat conditions * Lentic * Littoral Subject RIV: EG - Zoology Impact factor: 2.275, year: 2014

The Eurasian Economic Union and the Silk Road Economic Belt: Opportunities for Russia

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Igor Makarov

2016-09-01

Full Text Available This article considers the opportunities for Russia presented by the launch of China’s Silk Road Economic Belt initiative.This initiative is a comprehensive project for the rapid development of Central Asian countries, and not limited only to transportand logistics to guarantee the supply of Chinese goods to Europe. It is also China’s response to economic and political processes both within the country and in the Asia-Pacific region: the economic slow down and transformation of its social and economic model, diverging income levels, the growing presence of the United States in Asia, and the new divisions of labour within the region. The Silk Road initiative is based on China’s intention to create strong regional value chains, to outsource labour-intensive and environmentally harmful production, to foster the development of north west China including securing political stability in the Xinjiang Uighur Autonomous Region, and to guarantee the use of Chinese construction firms’ capacity. Goods transit is a secondary priority and justified not by commercial benefits from using land routes, but by the need to diversify export risks, arising due to the deteriorating military and political situation in the South China Sea. The 2015 Joint Statement on Cooperation on the Construction of Joint Eurasian Economic Union and the Silk Road Economic Belt projects resolves the issue of all egedly competitive goals of these complementary projects. The Eurasian Economic Union (EEU provides an institutional base for cooperation while the Silk Road initiative provide investments for their development. Russia may benefit from participating in the Silk Road initiative. First, it would help integrate its transportation system into the region’s logistics network and provide additional opportunities for transit and associated logistical services as well as access to growing regional markets. Second, the Silk Road initiative offers opportunities to strengthen

Gene structure of the pregnancy-associated glycoprotein-like (PAG-L) in the Eurasian beaver (Castor fiber L.).

Science.gov (United States)

Lipka, Aleksandra; Majewska, Marta; Panasiewicz, Grzegorz; Bieniek-Kobuszewska, Martyna; Szafranska, Bozena

2017-09-01

The pregnancy-associated glycoprotein-like family (PAG-L) is a large group of chorionic products, expressed in the pre-placental trophoblast and later in the post-implantational chorionic epithelium, and are involved in proper placenta development and embryo-maternal interaction in eutherians. This study describes identification of the PAG-L family in the genome of the Eurasian beaver (Castor fiber L.), named CfPAG-L. We identified 7657 bp of the CfPAG-L gDNA sequence (Acc. No. KX377932), encompassing nine exons (1-9) and eight introns (A-H). The length of the CfPAG-L exons (59-200 bp) was equivalently similar to the only known counterparts of bPAG1, bPAG2, and pPAG2. The length of the CfPAG-L introns ranged 288-1937 bp and was completely different from previously known PAG introns. The exonic CfPAG-L regions revealed 50.3-72.9% homology with equivalent segments of bPAG1 and pPAG2 structure. The intronic CfPAG-L regions alignments revealed a lack of homology. Within the entire CfPAG-L gene, 31 potential single nucleotide variants (SNV: 7 transversions and 24 transitions) were predicted. The identified exonic polymorphic loci did not affect the amino acid sequence of the CfPAG-L polypeptide precursor. This is the first report describing the CfPAG-L gene sequence, structural organization, and SNVs in the Eurasian beaver, one of the largest rodents.

Considerations regarding the occurence of the Eurasian Beaver (Castor fiber Linnaeus 1758 in the Danube Delta (Romania

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ALEXE Vasile

2012-09-01

Full Text Available On its original Romanian name - breb, the Eurasian Beaver (Castor fiber extinct at us for almost two centuries and reintroduced in some areas of the country, at present is better known under the name of his North American relative, beaver. In the last decades, this specie has been reintroduced within in its old habitats from where itwas extinct, especially under the effect of human pressure. Since 1998, reinsertion actions took place in Romania, in many areas, the closest one to Danube Delta area being the lower part of Ialomita river. By 2011 epigraphic or paleozoology evidences about the presence of this mammalian into the actual Delta have not been found, except the Lower Danube, up to Isaccea, but also near Dobrogea Plateau in Murighiol area. Its last Paleontology evidences come from early medieval period. Until now, the actual delta was considered a territory inappropriate for the Eurasian Beaver, due to high fluctuations of the water levels. But, in April 2011, the spontaneous appearance of the European beaver near Maliuc area was proved, a copy killed by poachers. In July 2011, a Beaver injured after the collision with a boat was found and scientifically investigated. The future observations will have to document if this mammal extends its habitat up here or remains an erratic appearance. In case of success of spontaneous colonization, its consequences and effects on the environment in general and on biodiversity inparticular are required to be monitored.

Lateral variations in the crustal structure of the Indo-Eurasian collision zone

Science.gov (United States)

Gilligan, Amy; Priestley, Keith

2018-05-01

The processes involved in continental collisions remain contested, yet knowledge of these processes is crucial to improving our understanding of how some of the most dramatic features on Earth have formed. As the largest and highest orogenic plateau on Earth today, Tibet is an excellent natural laboratory for investigating collisional processes. To understand the development of the Tibetan Plateau we need to understand the crustal structure beneath both Tibet and the Indian Plate. Building on previous work, we measure new group velocity dispersion curves using data from regional earthquakes (4424 paths) and ambient noise data (5696 paths), and use these to obtain new fundamental mode Rayleigh Wave group velocity maps for periods from 5-70 s for a region including Tibet, Pakistan and India. The dense path coverage at the shortest periods, due to the inclusion of ambient noise measurements, allows features of up to 100 km scale to be resolved in some areas of the collision zone, providing one of the highest resolution models of the crust and uppermost mantle across this region. We invert the Rayleigh wave group velocity maps for shear wave velocity structure to 120 km depth and construct a 3D velocity model for the crust and uppermost mantle of the Indo-Eurasian collision zone. We use this 3D model to map the lateral variations in the crust and in the nature of the crust-mantle transition (Moho) across the Indo-Eurasian collision zone. The Moho occurs at lower shear velocities below north eastern Tibet than it does beneath western and southern Tibet and below India. The east-west difference across Tibet is particularly apparent in the elevated velocities observed west of 84° E at depths exceeding 90 km. This suggests that Indian lithosphere underlies the whole of the Plateau in the west, but possibly not in the east. At depths of 20-40 km our crustal model shows the existence of a pervasive mid-crustal low velocity layer (˜10% decrease in velocity, Vs Vsv. The

Genetic structure within and among regional populations of the Eurasian badger (Meles meles) from Denmark and the Netherlands

DEFF Research Database (Denmark)

Zande, L. van de; Vliet, M. van de; Pertoldi, C.

2007-01-01

The Eurasian badger Meles meles has a wide distribution area ranging from Japan to Ireland. In western Europe badger habitats are severely disturbed by anthropogenic factors, leading to fragmentation into subpopulations and formation of a metapopulation substructuring of once continuous panmictic...... to this structuring of badger populations. In contrast, measures that improve migration and connection to other populations from neighboring countries may have prevented substructuring of the Dutch badger population....

Medieval Nomads – Sixth International Conference on the Medieval History of the Eurasian Steppe (Szeged, Hungary, November 23–26, 2016

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Aleksandar Uzelac

2017-06-01

Full Text Available Sixth international conference dedicated to the Medieval History of the Eurasian Steppe took place in the Hungarian city of Szeged on November 23-26, 2016. The organizer of the event was MTA-SZTE (“Hungarian Academy of Sciences – University of Szeged” Turkological Research group of the departments of Altaic and Medieval Studies at the Faculty of Arts, University of Szeged. More than thirty scholars from Hungary, Russia, Turkey, China, Spain, Bulgaria and Serbia took part in this event. The working languages of the conference were English and Russian. Presented papers dealt with various aspects of the history of Eurasian nomads, from the Early Middle Ages up to the seventeenth century. Among them, several have been related to the history of the Golden Horde. The proceedings of the conference are planned to be published in 2017, as a separate volume of the journal Chronica – Annual of The Institute of History, University of Szeged. Considering the quality and variety of the papers, presented at this occasion, there is no doubt it will attract the attention of the growing community of researchers and scholars interested in the medieval history of Eurasia.

Effects of sea-ice light attenuation and CDOM absorption in the water below the Eurasian sector of central Arctic Ocean (>88°N)

NARCIS (Netherlands)

Lund-Hansen, L.C.; Markager, S.; Hancke, K.; Stratmann, T.; Rysgaard, S.; Ramløv, H.; Sorrell, B.K.

2015-01-01

This is a study of the optical, physical and biological parameters of sea ice and the water below it at stations (n=25) in the central (>88°N) Eurasian sector of the Arctic Ocean during the summer 2012 record low sea-ice minimum extent. Results show that photosynthetically active radiation (PAR)

Potential direct and indirect effects of climate change on a shallow natural lake fish assemblage

Science.gov (United States)

Breeggemann, Jason J.; Kaemingk, Mark A.; DeBates, T.J.; Paukert, Craig P.; Krause, J.; Letvin, Alexander P.; Stevens, Tanner M.; Willis, David W.; Chipps, Steven R.

2015-01-01

Much uncertainty exists around how fish communities in shallow lakes will respond to climate change. In this study, we modelled the effects of increased water temperatures on consumption and growth rates of two piscivores (northern pike [Esox lucius] and largemouth bass [Micropterus salmoides]) and examined relative effects of consumption by these predators on two prey species (bluegill [Lepomis macrochirus] and yellow perch [Perca flavescens]). Bioenergetics models were used to simulate the effects of climate change on growth and food consumption using predicted 2040 and 2060 temperatures in a shallow Nebraska Sandhill lake, USA. The patterns and magnitude of daily and cumulative consumption during the growing season (April–October) were generally similar between the two predators. However, growth of northern pike was always reduced (−3 to −45% change) compared to largemouth bass that experienced subtle changes (4 to −6% change) in weight by the end of the growing season. Assuming similar population size structure and numbers of predators in 2040–2060, future consumption of bluegill and yellow perch by northern pike and largemouth bass will likely increase (range: 3–24%), necessitating greater prey biomass to meet future energy demands. The timing of increased predator consumption will likely shift towards spring and fall (compared to summer), when prey species may not be available in the quantities required. Our findings suggest that increased water temperatures may affect species at the edge of their native range (i.e. northern pike) and a potential mismatch between predator and prey could exist.

Consumption dynamics of the adult piscivorous fish community in Spirit Lake, Iowa

Science.gov (United States)

Liao, H.; Pierce, C.L.; Larscheid, J.G.

2004-01-01

At Spirit Lake, one of Iowa's most important fisheries, walleye Sander vitreus (formerly Stizostedion vitreum) is one of the most popular species with anglers. Despite a century of walleye stocking and management in Spirit Lake, walleye growth rate, size structure, and angler harvest continue to decline. Our purpose was to determine the magnitude and dynamics of walleye population consumption relative to those of other piscivorous species in Spirit Lake, which would allow managers to judge the feasibility of increasing the abundance, growth rate, and size structure of the walleye population. We quantified food consumption by the adult piscivorous fish community in Spirit Lake over a 3-year period. Data on population dynamics, diet, energy density, and water temperature from 1995 to 1997 were used in bioenergetics models to estimate total consumption by walleye, yellow perch Perca flavescens, smallmouth bass Micropterus dolomieu, largemouth bass Micropterus salmoides, black crappie Pomoxis nigromaculatus, and northern pike Esox lucius. Estimated annual consumption by the piscivorous community varied roughly fourfold, ranging from 154,752 kg in 1995 to 662,776 kg in 1997. Walleyes dominated total consumption, accounting for 68, 73, and 90% (1995-1997, respectively) of total food consumption. Walleyes were also the dominant consumers of fish, accounting for 76, 86, and 97% of piscivorous consumption; yellow perch followed, accounting for 16% of piscivorous consumption in 1995 and 12% in 1996. Yellow perch were the predominant fish prey species in all 3 years, accounting for 68, 52, and 36% of the total prey consumed. Natural reproduction is weak, so high walleye densities are maintained by intensive stocking. Walleye stocking drives piscivorous consumption in Spirit Lake, and yearly variation in the cannibalism of stocked walleye fry may be an important determinant of walleye year-class strength and angler success. Reducing walleye stocking intensity, varying stocking

Distribution of Eurasian minnows (Phoxinus: Cypriniformes in the Western Balkans

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Vucić Matej

2018-01-01

Full Text Available The Eurasian minnows of the genus Phoxinus are small cyprinid species, widely distributed across Europe and Asia. Currently, there are at least 15 species in Phoxinus, with preliminary data suggesting more to be described. Despite the discernible increase in research integrating molecular phylogenetic approaches with traditional taxonomy and systematics, inter- and intraspecific relationships in the genus Phoxinus are still poorly known. The aims of this research were to: (i compile data on the distribution of Phoxinus species in Croatia and Bosnia and Herzegovina from the sampling conducted by authors from 2006 to 2016 and from literature sources, and (ii provide a detailed insight on distribution ranges of genetic clades and species of Phoxinus in the western Balkans. Additional 118 localities in Croatia and 8 locations in Bosnia and Herzegovina were added to already known 160 localities from the literature data. Molecular analyses of mitochondrial DNA indicate: (i the presence of Phoxinus marsilii in Croatia (Drava drainage, the Papuk Mountain, around 260 km south of its known distribution range in Hungary, and (ii an exceptional genetic variability of P. lumaireul in the Western Balkans.

Survival and development of Lymantria monacha (Lepidoptera: Lymantriidae) on North American and introduced Eurasian tree species.

Science.gov (United States)

Keena, M A

2003-02-01

Lymantria monacha (L.) (Lepidoptera: Lymantriidae), the nun moth, is a Eurasian pest of conifers that has potential for accidental introduction into North America. To project the potential host range of this insect if introduced into North America, survival and development of L. monacha on 26 North American and eight introduced Eurasian tree species were examined. Seven conifer species (Abies concolor, Picea abies, P. glauca, P. pungens, Pinus sylvestris with male cones, P. menziesii variety glance, and Tsuga canadensis) and six broadleaf species (Betula populifolia, Malus x domestica, Prunus serotiaa, Quercus lobata, Q. rubra, and Q. velutina) were suitable for L. monacha survival and development. Eleven of the host species tested were rated as intermediate in suitability, four conifer species (Larix occidentalis, P. nigra, P. ponderosa, P. strobus, and Pseudotsuga menziesii variety menziesii) and six broadleaf species (Carpinus caroliniana, Carya ovata, Fagus grandifolia, Populus grandidentata, Q. alba, and Tilia cordata) and the remaining 10 species tested were rated as poor (Acer rubrum, A. platanoidies, A. saccharum, F. americana, Juniperus virginiana, Larix kaempferi, Liriodendron tulipfera, Morus alba, P. taeda, and P. deltoides). The phenological state of the trees had a major impact on establishment, survival, and development of L. monacha on many of the tree species tested. Several of the deciduous tree species that are suitable for L. monacha also are suitable for L. dispar (L.) and L. mathura Moore. Establishment of L. monacha in North America would be catastrophic because of the large number of economically important tree species on which it can survive and develop, and the ability of mated females to fly and colonize new areas.

Improvement in simulation of Eurasian winter climate variability with a realistic Arctic sea ice condition in an atmospheric GCM

International Nuclear Information System (INIS)

Lim, Young-Kwon; Ham, Yoo-Geun; Jeong, Jee-Hoon; Kug, Jong-Seong

2012-01-01

The present study investigates how much a realistic Arctic sea ice condition can contribute to improve simulation of the winter climate variation over the Eurasia region. Model experiments are set up using different sea ice boundary conditions over the past 24 years (i.e., 1988–2011). One is an atmospheric model inter-comparison (AMIP) type of run forced with observed sea-surface temperature (SST), sea ice, and greenhouse gases (referred to as Exp RSI), and the other is the same as Exp RSI except for the sea ice forcing, which is a repeating climatological annual cycle (referred to as Exp CSI). Results show that Exp RSI produces the observed dominant pattern of Eurasian winter temperatures and their interannual variation better than Exp CSI (correlation difference up to ∼0.3). Exp RSI captures the observed strong relationship between the sea ice concentration near the Barents and Kara seas and the temperature anomaly across Eurasia, including northeastern Asia, which is not well captured in Exp CSI. Lagged atmospheric responses to sea ice retreat are examined using observations to understand atmospheric processes for the Eurasian cooling response including the Arctic temperature increase, sea-level pressure increase, upper-level jet weakening and cold air outbreak toward the mid-latitude. The reproducibility of these lagged responses by Exp RSI is also evaluated. (letter)

Improvement in Simulation of Eurasian Winter Climate Variability with a Realistic Arctic Sea Ice Condition in an Atmospheric GCM

Science.gov (United States)

Lim, Young-Kwon; Ham, Yoo-Geun; Jeong, Jee-Hoon; Kug, Jong-Seong

2012-01-01

The present study investigates how much a realistic Arctic sea ice condition can contribute to improve simulation of the winter climate variation over the Eurasia region. Model experiments are set up using different sea ice boundary conditions over the past 24 years (i.e., 1988-2011). One is an atmospheric model inter-comparison (AMIP) type of run forced with observed sea-surface temperature (SST), sea ice, and greenhouse gases (referred to as Exp RSI), and the other is the same as Exp RSI except for the sea ice forcing, which is a repeating climatological annual cycle (referred to as Exp CSI). Results show that Exp RSI produces the observed dominant pattern of Eurasian winter temperatures and their interannual variation better than Exp CSI (correlation difference up to approx. 0.3). Exp RSI captures the observed strong relationship between the sea ice concentration near the Barents and Kara seas and the temperature anomaly across Eurasia, including northeastern Asia, which is not well captured in Exp CSI. Lagged atmospheric responses to sea ice retreat are examined using observations to understand atmospheric processes for the Eurasian cooling response including the Arctic temperature increase, sea-level pressure increase, upper-level jet weakening and cold air outbreak toward the mid-latitude. The reproducibility of these lagged responses by Exp RSI is also evaluated.

On the Fruit Consumption of Eurasian Badger (Meles meles (Mammalia: Mustelidae during the Autumn Season in Sredna Gora Mountains (Bulgaria

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Dilian G. Georgiev

2009-07-01

Full Text Available This case study was carried out at one badgers family territory by asingle collection (11.11.2002, north of Stara Zagora City, near Tabashka River of faeces from the animal latrine sites. Total of 1361 individual food items were identified in Eurasian badger (Meles meles faeces from which the fruits of the Cornel-tree (Cornus mas strongly dominated (n=1332, 96.5% from all items, 98.2% from all fruits.

Life-history dependent relationships between body condition and immunity, between immunity indices in male Eurasian tree sparrows.

Science.gov (United States)

Zhao, Yuliang; Li, Mo; Sun, Yanfeng; Wu, Wei; Kou, Guanqun; Guo, Lingling; Xing, Danning; Wu, Yuefeng; Li, Dongming; Zhao, Baohua

2017-08-01

In free-living animals, recent evidence indicates that innate, and acquired, immunity varies with annual variation in the demand for, and availability of, food resources. However, little is known about how animals adjust the relationships between immunity and body condition, and between innate and acquired immunity to optimize survival over winter and reproductive success during the breeding stage. Here, we measured indices of body condition (size-corrected mass [SCM], and hematocrit [Hct]), constitutive innate immunity (plasma total complement hemolysis activity [CH 50 ]) and acquired immunity (plasma immunoglobulin A [IgA]), plus heterophil/lymphocyte (H/L) ratios, in male Eurasian tree sparrows (Passer montanus) during the wintering and the breeding stages. We found that birds during the wintering stage had higher IgA levels than those from the breeding stage. Two indices of body condition were both negatively correlated with plasma CH 50 activities, and positively with IgA levels in wintering birds, but this was not the case in the breeding birds. However, there was no correlation between CH 50 activities and IgA levels in both stages. These results suggest that the relationships between body condition and immunity can vary across life-history stage, and there are no correlations between innate and acquired immunity independent of life-history stage, in male Eurasian tree sparrows. Therefore, body condition indices predict immunological state, especially during the non-breeding stage, which can be useful indicators of individual immunocompetences for understanding the variations in innate and acquired immunity in free-living animals. Copyright © 2017 Elsevier Inc. All rights reserved.

The fate of terrigenous dissolved organic carbon on the Eurasian shelves and export to the North Atlantic

Science.gov (United States)

Kaiser, Karl; Amon, Rainer; Benner, Ronald

2017-04-01

Dissolved lignin phenols, chromophoric dissolved organic matter (CDOM) absorption, and fluorescence were analyzed along cross-slope mooring locations in the Barents, Laptev, and East Siberian Seas to gain a better understanding of terrigenous dissolved organic carbon (tDOC) dynamics in Arctic shelf seas and the Arctic Ocean. A gradient of river water and tDOC was observed along the continental shelf eastward into the East Siberian Sea. Correlations of carbon-normalized yields of lignin-derived phenols supplied by Siberian rivers with river water fractions and known water residence times yielded in situ decay constants of 0.18-0.58 per year. Calculations showed about 50% of annual tDOC discharged by Siberian rivers was mineralized in estuaries and on the Eurasian shelves per year indicating extensive removal of tDOC. Bioassay experiments and in situ decay constants indicated a reactivity continuum for tDOC. CDOM parameters and acid/aldehyde ratios of vanillyl (V) and syringyl (S) lignin phenols showed biomineralization was the dominant mechanism for the removal of tDOC. Characteristic ratios of p-hydroxy (P), S, and V phenols (P/V, S/V) also identified shelf regions in the Kara Sea and regions along the Western Laptev Sea shelf where formation of Low Salinity Halocline Waters (LSHW) and Lower Halocline Water (LHW) occurred. The efficient removal of tDOC demonstrates the importance of Eurasian margins as sinks of tDOC derived from the large Siberian Rivers and confirms tDOC mineralization has a major impact on nutrients budgets, air-sea CO2 exchange, and acidification in the Siberian Shelf Seas.

Fish Scale Evidence for Rapid Post Glacial Colonization of an Atlantic Coastal Pond

Science.gov (United States)

Daniels, R. A.; Peteet, Dorothy

1996-01-01

Fish scales from the sediment of Allamuchy Pond, New Jersey, USA, indicate that fishes were present in the pond within 400 years of the time of the first deposition of organic material, at approximately 12,600 yrs BP. The earliest of the scales, from a white sucker, Catostomus commersoni, appears in sediment dated 12,260 +/- 220 yrs BP. Presence of scales in sediment deposited before I 0,000 yrs BP indicates that Atlantic salmon, Salmo salar, sunfish, Lepomis sp., and yellow perch, Perca flavescens, also were early inhabitants of the pond. The timing of the arrival of each of these fishes suggests that they migrated out from Atlantic coastal refugia. A minnow scale, referred to Phoxininae, was also retrieved; it could not be matched to any cyprinid currently found in northeastern North America. The species present historically in this pond are from five families found currently in ponds throughout the Northeast and sugoest that the lentic palaeo-enviromnent was similar to present mid-elevation or high-latitude lentic systems.

Spectral characteristics of the P codas of eurasian earthquakes and explosions

International Nuclear Information System (INIS)

Evernden, J.F.

1977-01-01

Spectral analysis of ''infinite velocity sum'' subarray beams at LASA for the P codas of 36 explosions and 23 earthquakes indicates the presence of 6 to 9 Hz energy well above noise level for large explosions and earthquakes. A discriminant (D), based on use of the full spectral bandwidth from 0.4 to 9 Hz, successfully discriminates all Eurasian explosions and shallow-focus earthquakes. The basic character and contrast in spectral composition of the source spectra of earthquakes and explosions is discussed. It is pointed out that the discriminant (D), when use is made of signals recorded in the range 60 0 to 90 0 , is as or more successful in discriminating events of near m/sub b/ 4.0 as those at and above m/sub b/ 6.0, and the basis for this success is clarified. It is suggested that proper use of P coda spectral discriminants appears capable of achieving identification essentially at the detection threshold of a network, while circumventing such problems as refined depths of focus, mixed events, etc

Eurasian Higher Education Leaders' Forum: Higher Education and Modernization of the Economy: Innovative and Entrepreneurial Universities. Conference Proceedings (5th, Astana, Kazakhstan, May 26, 2016)

Science.gov (United States)

Sagintayeva, Aida, Ed.; Kurakbayev, Kairat, Ed.

2016-01-01

This collection of papers introduces the proceedings of the fifth Annual Conference--"Eurasian Higher Education Leaders' Forum" held on the 26th May, 2016 at Nazarbayev University in Astana, Kazakhstan. The contributors include university presidents, rectors, deans, directors of professional development and leadership programs, faculty…

An artificial perch to help Snail Kites handle an exotic Apple Snail

Science.gov (United States)

Pias, Kyle E.; Welch, Zach C.; Kitchens, Wiley M.

2012-01-01

In the United States, the Snail Kite (Rostrhamus sociabilis plumbeus) is a federally endangered species and restricted to the wetlands of south-central Florida where the current population numbers less than 1,500. The Snail Kite is an extreme dietary specialist, previously feeding almost exclusively on one species of snail, the Florida Apple Snail (Pomacea paludosa). Within the past decade, an exotic species of apple snail, the Island Apple Snail (Pomacea insularum), has become established on lakes in central Florida. Island Apple Snails are larger than the native Florida Apple Snails, and Snail Kites handle the exotic snails less efficiently. Juvenile Snail Kites, in particular, have lower daily energy balances while feeding on Island Apple Snails. An inexpensive, easy-to-construct platform was developed that would provide Snail Kites with a flat, stable surface on which to extract snails. The platform has the potential to reduce the difficulties Snail Kites experience when handling exotic snails, and may benefit the Snail Kite population as a whole. Initial observations indicate that Snail Kites use the platforms frequently, and snails extracted at the platforms are larger than snails extracted at other perches.

Impact of Salinity on the Incubation Rate and the Performance during the Nursery Phase of Square Head Climbing Perch (Anabas testudineus Bloch, 1792

Directory of Open Access Journals (Sweden)

Le, DV.

2016-01-01

Full Text Available Square head climbing perch (Anabas testudineus Bloch, 1792 is a high quality fish without small bones. It grows in a wide range of temperatures (10-42 oC, pH (3.5-9.5 and salinity (up to 16%. As regards climate change, this species may become important for aquaculture in the Tam Giang-Cau Hai lagoon near Hue city. To optimise the quality of fingerlings, we analyzed the effect of salinity levels on hatching and nursing in three subsequent experiments. Fertilization, hatching, survival and growth rates for 30 days were determined at salinity levels 0%, 5%, 7%, 13% and 15%. Water temperature and pH varied between 22-29.5 oC and 7.3-7.8, respectively. Between 0-5%, fertilization ratio was 77% to 83% and highest at 5%, but this dropped to 0% when salinity increased; hatching ratio was larger than 90%, but decreased to 0% at 13-15%. Between 0-11%, hatching time of fertilized eggs was not affected by salinity levels. The ratio of deformation gradually increased above 5%. After hatching at either 0 or 5%, survival ratios for square head climbing perch were above 13% up to 5%, but dropped to 0% at 9%. The growth after 30 days of nursing was higher at 5 and 7% compared with that of 0 and 3%.

Ceramics among Eurasian hunter-gatherers: 32 000 years of ceramic technology use and the perception of containment

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Mihael Budja

2016-12-01

Full Text Available We present two parallel and 32 000 years long trajectories of episodic ceramic technology use in Eurasian pre-Neolithic hunter-gatherer societies. In eastern, Asian trajectory the pottery was produced from the beginning. Ceramic figurines mark the western, European trajectory. The western predates the eastern for about eleven millennia. While ceramic cones and figurines first appeared in Central Europe at c. 31 000 cal BC the earliest vessels in eastern Asia was dated at c. 20 000 cal BC. We discuss women’s agency, perception of containment, ‘cross-craft interactions’, and evolution of private property that that may influenced the inventions of ceramic (pyrotechnology.

Identification of West Eurasian mitochondrial haplogroups by mtDNA SNP screening: results of the 2006-2007 EDNAP collaborative exercise

DEFF Research Database (Denmark)

Parson, Walther; Fendt, Liane; Ballard, David

2008-01-01

no previous experience with the technology and/or mtDNA analysis. The results of this collaborative exercise stimulate the expansion of screening methods in forensic laboratories to increase efficiency and performance of mtDNA typing, and thus demonstrates that mtDNA SNP typing is a powerful tool for forensic......The European DNA Profiling (EDNAP) Group performed a collaborative exercise on a mitochondrial (mt) DNA screening assay that targeted 16 nucleotide positions in the coding region and allowed for the discrimination of major west Eurasian mtDNA haplogroups. The purpose of the exercise was to evaluate...

An update of hydrologic conditions and distribution of selected constituents in water, eastern Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2009–11

Science.gov (United States)

Davis, Linda C.; Bartholomay, Roy C.; Rattray, Gordon W.

2013-01-01

Since 1952, wastewater discharged to infiltration ponds (also called percolation ponds) and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain (ESRP) aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, maintains groundwater monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from aquifer, multilevel monitoring system (MLMS), and perched groundwater wells in the USGS groundwater monitoring networks during 2009–11. Water in the ESRP aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer primarily is recharged from infiltration of irrigation water, infiltration of streamflow, groundwater inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March–May 2009 to March–May 2011, water levels in wells generally declined in the northern part of the INL. Water levels generally rose in the central and eastern parts of the INL. Detectable concentrations of radiochemical constituents in water samples from aquifer wells or MLMS equipped wells in the ESRP aquifer at the INL generally decreased or remained constant during 2009–11. Decreases in concentrations were attributed to radioactive decay, changes in waste-disposal methods, and dilution from recharge and underflow. In 2011, concentrations of tritium in groundwater from 50 of 127 aquifer wells were greater than or equal to the reporting level and ranged from 200±60 to 7,000±260 picocuries per liter. Tritium concentrations from one or more discrete zones from four wells equipped with MLMS were greater than or

A reverse genetics system for the Great Lakes strain of viral hemorrhagic septicemia virus: the NV gene is required for pathogenicity

Science.gov (United States)

Ammayappan, Arun; Kurath, Gael; Thompson, Tarin M.; Vakharia, Vikram N.

2011-01-01

Viral hemorrhagic septicemia virus (VHSV), belonging to the genus Novirhabdovirus in the family of Rhabdoviridae, causes a highly contagious disease of fresh and saltwater fish worldwide. Recently, a novel genotype of VHSV, designated IVb, has invaded the Great Lakes in North America, causing large-scale epidemics in wild fish. An efficient reverse genetics system was developed to generate a recombinant VHSV of genotype IVb from cloned cDNA. The recombinant VHSV (rVHSV) was comparable to the parental wild-type strain both in vitro and in vivo, causing high mortality in yellow perch (Perca flavescens). A modified recombinant VHSV was generated in which the NV gene was substituted with an enhanced green fluorescent protein gene (rVHSV-ΔNV-EGFP), and another recombinant was made by inserting the EGFP gene into the full-length viral clone between the P and M genes (rVHSV-EGFP). The in vitro replication kinetics of rVHSV-EGFP was similar to rVHSV; however, the rVHSV-ΔNV-EGFP grew 2 logs lower. In yellow perch challenges, wtVHSV and rVHSV induced 82-100% cumulative per cent mortality (CPM), respectively, whereas rVHSV-EGFP produced 62% CPM and rVHSV-ΔNV-EGFP caused only 15% CPM. No reversion of mutation was detected in the recovered viruses and the recombinant viruses stably maintained the foreign gene after several passages. These results indicate that the NV gene of VHSV is not essential for viral replication in vitro and in vivo, but it plays an important role in viral replication efficiency and pathogenicity. This system will facilitate studies of VHSV replication, virulence, and production of viral vectored vaccines.

Diet composition and fish consumption of double-crested cormorants from three St. Lawrence River Colonies in 2013

Science.gov (United States)

Johnson, James H.; Farquhar, James F.; Mazzocchi, Irene M.; Bendig, Anne

2014-01-01

Double-crested Cormorants (Phalacrocorax auritus) were first observed nesting in the upper St. Lawrence River at Strachan Island in 1992. Cormorants now nest at a number of islands in the Thousand Islands section of the river. Griswold, McNair, and Strachan islands are among the largest colonies in the upper river. Until 2011, nest counts had remained relatively stable, ranging from 200 to 603 nests per colony. However, since 2011 the number of nests at McNair Island have exceeded 700 each year. Although the size of cormorant colonies in the upper St. Lawrence River is smaller than those in the eastern basin of Lake Ontario, the close proximity of islands in the upper river that have colonies may cause a cumulative fish consumption effect similar to a larger colony. Because of increasing numbers of Double-crested Cormorants in the upper St. Lawrence River and the possible effects on fish populations, studies were initiated in 1999 to quantify cormorant diet and fish consumption at the three largest colonies. From 1999 to 2012, these studies have shown that cormorants consumed about 128.6 million fish including 37.5 million yellow perch (Perca flavescens), 17.4 million rock bass (Ambloplites rupestris) and 1.0 million smallmouth bass (Micropterus dolemieu) (Johnson et al. 2012). During this same time period fish assessment studies near some of these islands have shown a major decrease in yellow perch populations (Klindt 2007). This occurrence is known as the halo effect and happens when piscivorous birds deplete local fish populations in areas immediately surrounding the colony (Ashmole 1963). This paper describes the diet and fish consumption of cormorants in the upper St. Lawrence River in 2013.

Species‐ and habitat‐specific otolith chemistry patterns inform riverine fisheries management

Science.gov (United States)

Radigan, William; Carlson, Andrew K.; Kientz, Jeremy; Chipps, Steven R.; Fincel, Mark J.; Graeb, Brian D. S.

2018-01-01

Geology and hydrology are drivers of water chemistry and thus important considerations for fish otolith chemistry research. However, other factors such as species and habitat identity may have predictive ability, enabling selection of appropriate elemental signatures prior to costly, perhaps unnecessary water/age‐0 fish sampling. The goal of this study was to develop a predictive methodology for using species and habitat identity to design efficient otolith chemistry studies. Duplicate water samples and age‐0 fish were collected from 61 sites in 4 Missouri River reservoirs for walleye Sander vitreus and one impoundment (Lake Sharpe, South Dakota) for other fishes (bluegill Lepomis macrochirus, black crappie Pomoxis nigromaculatus, gizzard shad Dorosoma cepedianum, largemouth bass Micropterus salmoides, smallmouth bass M. dolomieu, white bass Morone chrysops, white crappie P. annularis, and yellow perch Perca flavescens). Water chemistry (barium:calcium [Ba:Ca], strontium:calcium [Sr:Ca]) was temporally stable, spatially variable, and highly correlated with otolith chemistry for all species except yellow perch. Classification accuracies based on bivariate Ba:Ca and Sr:Ca signatures were high (84% across species) yet varied between floodplain and main‐channel habitats in a species‐specific manner. Thus, to maximize the reliability of otolith chemistry, researchers can use species classifications presented herein to inform habitat selection (e.g., study reservoir‐oriented species such as white bass in main‐channel environments) and habitat‐based classifications to inform species selection (e.g., focus floodplain studies on littoral species such as largemouth bass). Overall, species and habitat identity are important considerations for efficient, effective otolith chemistry studies that inform and advance fisheries and aquatic resource management.

SEM study of the effects of crude oil on the gills and air breathing organs of climbing perch, Anabas testudineus

International Nuclear Information System (INIS)

Prasad, M.S.

1991-01-01

Ultrastructural studies on the effects of crude oil on the gills are scanty. Recently, researchers studied the effect of crude oil on the air breathing organs of striped gourami using scanning electron microscope and observed mucous cell hyperplasia coupled with telangiectasis in the epithelia of air breathing organs. The present investigation has been undertaken to study crude oil toxicity by observing the morphological changes occurring in the epithelia of gills and air breathing organs of climbing perch, Anabas testudineus at SEM level. Since the epithelia of gills and air breathing organs function in two different media, a comparative account for their sensitivity to crude oil solutions would be informative

Effects of freezing on white perch Morone americana (Gmelin, 1789): Implications for multivariate morphometrics

Science.gov (United States)

Kocovsky, Patrick

2016-01-01

This study tested the hypothesis that duration of freezing differentially affects whole-body morphometrics of a derived teleost. Whole-body morphometrics are frequently analyzed to test hypotheses of different species, or stocks within a species, of fishes. Specimens used for morphometric analyses are typically fixed or preserved prior to analysis, yet little research has been done on how fixation or preservation methods or duration of preservation of specimens might affect outcomes of multivariate statistical analyses of differences in shape. To determine whether whole-body morphometrics changed as a result of freezing, 23 whole-body morphometrics of age-1 white perch (Morone americana) from western Lake Erie (n = 211) were analyzed immediately after capture, after being held on ice overnight, and after freezing for 100 or 200 days. Discriminant function analysis revealed that all four groups differed significantly from one another (P time to avoid biases related to the length of time they were frozen. Similar experiments should be conducted on other species and also using formalin- and alcohol-preserved specimens.

Foot preferences during resting in wildfowl and waders.

Science.gov (United States)

Randler, Christoph

2007-03-01

Footedness in birds has been reported, e.g., in parrots and chickens, but the direction of footedness remained unclear. Is a bird left-footed because it uses its left foot for holding and handling food, or is it right-footed because it uses the right foot for stabilisation and balancing while perching? In 2004 and 2006 I examined footedness in wildfowl and waders while the birds were performing a single task: roosting on the ground on one foot. Avocet (Recurvirostra avosetta), northern shoveller (Anas clypeata), oystercatcher (Haematopus ostralegus), and Eurasian curlew (Numenius arquata) were right-footed. Another 21 species did not show any significant foot preferences. This study provides some evidence that asymmetries in preferential foot use in birds may be triggered by a preference during postural control.

Long-Term Comparative Advantages of the Eurasian Economic Union Member States in International Trade

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Falkowski Krzysztof

2017-12-01

Full Text Available On 1st January 2015 the Eurasian Economic Union (EAEU - a new integration block comprising initially Belarus, Kazakhstan, and Russia, and later that year also Armenia and Kyrgyzstan - appeared on the world map. This paper endeavors to identify the EAEU countries’ long-term international comparative advantages within four basic groups of goods according to the OECD classification of manufacturing industries based on technology intensity. The analysis, using B. Balassa’s RCA methodology and covering the years 2000-2014, indicates that these countries lack competitiveness, with none of them possessing any RCAs in the high-technology category whereas in the medium-hightechnology category - only Belarus. In contrast, all the EAEU countries fared the best in the medium-low-technology category, which is mostly attributable to the resources-based character of their economies. Surprisingly, dramatically low international competitiveness was recorded by Kazakhstan and Russia.

Kazakhstan's economic soft balancing policy vis-à-vis Russia: From the Eurasian Union to the economic cooperation with Turkey

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Lyailya Nurgaliyeva

2016-01-01

When Russia started asserting its economic and political power over the Central Asian and Caspian regions, Nazarbayev once again resorted to the economic soft balancing policy, but this time by relying on outside players. Part 2 of this article discusses two cases of such external economic soft balancing efforts: participation in the Baku–Tbilisi–Ceyhan (BTC pipeline project, and the economic cooperation with Turkey as part of a free trade zone. The BTC pipeline project and the close economic cooperation with Turkey ended up being a more productive soft balancing effort than the earlier Eurasian Union initiative.

Quantifying the multiple, environmental benefits of reintroducing the Eurasian Beaver

Science.gov (United States)

Brazier, Richard; Puttock, Alan; Graham, Hugh; Anderson, Karen; Cunliffe, Andrew; Elliott, Mark

2016-04-01

Beavers are ecological engineers with an ability to modify the structure and flow of fluvial systems and create complex wetland environments with dams, ponds and canals. Consequently, beaver activity has potential for river restoration, management and the provision of multiple environmental ecosystem services including biodiversity, flood risk mitigation, water quality and sustainable drinking water provision. With the current debate surrounding the reintroduction of beavers into the United Kingdom, it is critical to monitor the impact of beavers upon the environment. We have developed and implemented a monitoring strategy to quantify the impact of reintroducing the Eurasian Beaver on multiple environmental ecosystem services and river systems at a range of scales. First, the experimental design and preliminary results will be presented from the Mid-Devon Beaver Trial, where a family of beavers has been introduced to a 3 ha enclosure situated upon a first order tributary of the River Tamar. The site was instrumented to monitor the flow rate and quality of water entering and leaving the site. Additionally, the impacts of beavers upon riparian vegetation structure, water/carbon storage were investigated. Preliminary results indicate that beaver activity, particularly the building of ponds and dams, increases water storage within the landscape and moderates the river response to rainfall. Baseflow is enhanced during dry periods and storm flow is attenuated, potentially reducing the risk of flooding downstream. Initial analysis of water quality indicates that water entering the site (running off intensively managed grasslands upslope), has higher suspended sediment loads and nitrate levels, than that leaving the site, after moving through the series of beaver ponds. These results suggest beaver activity may also act as a means by which the negative impact of diffuse water pollution from agriculture can be mitigated thus providing cleaner water in rivers downstream

Seeking explanations for recent changes in abundance of wintering Eurasian Wigeon (Anas penelope) in northwest Europe

DEFF Research Database (Denmark)

Fox, Anthony David; Dalby, Lars; Christensen, Thomas Kjær

2016-01-01

the range. However, because over 75% of the population of over 1 million individuals winters in Belgium, the Netherlands, UK and France, there was no evidence for a major movement in the centre of gravity of the wintering distribution. Between-winter changes in overall flyway abundance were highly......We analysed annual changes in abundance of Eurasian Wigeon (Anas penelope) derived from mid-winter International Waterbird Census data throughout its northwest European flyway since 1988 using log-linear Poisson regression modelling. Increases in abundance in the north and east of the wintering...... range (Norway, Sweden, Denmark, Germany, Switzerland), stable numbers in the central range (Belgium,Netherlands,UKand France) and declining abundance in the west and south of the wintering range (Spain and Ireland) suggest a shift in wintering distribution consistent with milder winters throughout...

Seasonal variation in Eurasian Wigeon Anas penelope sex and age ratios from hunter-based surveys

DEFF Research Database (Denmark)

Clausen, Kevin Kuhlmann; Dalby, Lars; Sunde, Peter

2013-01-01

dominated by adult males, and juvenile proportions were highest in November and significantly lower before and after this peak. Nationwide field assessments undertaken in January 2012 showed no significant differences from sex and age ratios in the wing survey data from that particular hunting season (2011...... schemes. This study found consistent seasonal variation in Eurasian Wigeon Anas penelope sex and age ratios among Danish hunter-based wing surveys, and describes how accounting for this variation might explain reported discrepancies between this and other monitoring methods. Early season flocks were....../2012), indicating that this survey is a good predictor of Wigeon demography. These results highlight the need to account for consistent temporal variation in such demographic time series when using the results to model population parameters....

Calcium and Strontium in Swedish Waters and Fish, and Accumulation of Strontium-90

Energy Technology Data Exchange (ETDEWEB)

Agnedal, P O

1966-04-15

The purpose of this study has been to investigate the correlation between calcium and strontium in fish in relation to the concentration of these elements in the water. An investigation of the uptake of strontium-90 has also been made and permissible levels of strontium-90 in the water is calculated based upon the uptake in fish muscle tissues. Lakes with calcium concentrations between 2 - 63 mg/l have been studied and samples from the Baltic coastal water are also included. Three fish species are studied, viz. pike (Esox lucius (L.)), perch (Perca fluviatilis (L.)) and roach (Leuciscus rutilus (L.)). Bones, muscle tissues and skin + scales have been analysed. Strontium-90 measurements have been made showing an increase in both water and fish. Calculations show that in water with about 2 mg Ca/l a 10-fold increase of the existing strontium-90 level might give strontium-90 concentrations in fish muscle tissues close to what is permissible. In lakes with calcium concentrations 20 - 40 mg/l the permissible levels for drinking water will be exceeded before the fish consumption would have to be restricted.

Stickleback Population

Directory of Open Access Journals (Sweden)

Ulrika Candolin

2012-01-01

Full Text Available Human-induced eutrophication has increased offspring production in a population of threespine stickleback Gasterosteus aculeatus in the Baltic Sea. Here, we experimentally investigated the effects of an increased density of juveniles on behaviours that influence survival and dispersal, and, hence, population growth—habitat choice, risk taking, and foraging rate. Juveniles were allowed to choose between two habitats that differed in structural complexity, in the absence and presence of predators and conspecific juveniles. In the absence of predators or conspecifics, juveniles preferred the more complex habitat. The preference was further enhanced in the presence of a natural predator, a perch Perca fluviatilis (behind a transparent Plexiglas wall. However, an increased density of conspecifics relaxed the predator-enhanced preference for the complex habitat and increased the use of the open, more predator-exposed habitat. Foraging rate was reduced under increased perceived predation risk. These results suggest that density-dependent behaviours can cause individuals to choose suboptimal habitats where predation risk is high and foraging rate low. This could contribute to the regulation of population growth in eutrophicated areas where offspring production is high.

Calcium and Strontium in Swedish Waters and Fish, and Accumulation of Strontium-90

International Nuclear Information System (INIS)

Agnedal, P.O.

1966-04-01

The purpose of this study has been to investigate the correlation between calcium and strontium in fish in relation to the concentration of these elements in the water. An investigation of the uptake of strontium-90 has also been made and permissible levels of strontium-90 in the water is calculated based upon the uptake in fish muscle tissues. Lakes with calcium concentrations between 2 - 63 mg/l have been studied and samples from the Baltic coastal water are also included. Three fish species are studied, viz. pike (Esox lucius (L.)), perch (Perca fluviatilis (L.)) and roach (Leuciscus rutilus (L.)). Bones, muscle tissues and skin + scales have been analysed. Strontium-90 measurements have been made showing an increase in both water and fish. Calculations show that in water with about 2 mg Ca/l a 10-fold increase of the existing strontium-90 level might give strontium-90 concentrations in fish muscle tissues close to what is permissible. In lakes with calcium concentrations 20 - 40 mg/l the permissible levels for drinking water will be exceeded before the fish consumption would have to be restricted

EURASIAN MINERAL WATER: MATHEMATICAL MODELING, CLASSIFICATION AND ASSESSMENT OF THEIR IMPACT ON THE BIOCHEMICAL COMPOSITION OF HUMAN BLOOD

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Nikolay Kornilov

2014-06-01

Full Text Available In the article the results of comparative analysis of the composition of the Eurasian hydromineral resources and the assessment of their impact on the physiological condition of a human organism according to biochemical studies of venous blood are presented. Processing of initial data on the composition and properties of mineral waters chloride-hydrocarbonate, sulphate- hydrocarbonate and chloride-sulphate types and venous blood are made using the method of mathematical modeling, developed by the authors of this article. It is shown that in the balneological impact of hydromineral resources on the body in the blood increases the hemoglobin and oxygen, decreases glucose, and acid-base pH shifted to high alkalinity.

The effects of a perch, dust bath, and nest box, either alone or in combination as used in furnished cages, on the welfare of laying hens.

Science.gov (United States)

Barnett, J L; Tauson, R; Downing, J A; Janardhana, V; Lowenthal, J W; Butler, K L; Cronin, G M

2009-03-01

This experiment examined the welfare-related effects of individual furniture items alone or in combination in a factorial experiment using Hy-Line Brown hens housed in 8-bird furnished cages. Welfare was assessed during two 8-wk sampling periods commencing at 29 and 59 wk of age. Measurement of stress, immunology, feather, foot and claw condition, and behavior were taken, and bone strength was measured at the end of the experiment. With the exception of the positive effects of a perch on bone strength, any effects of furniture items were relatively small, even though the furniture was extensively used. Although there were changes in behavior and small changes in feather, foot, and claw condition, it is unclear whether these changes have any meaningful implications for welfare. In this experiment there were 2 additional external control treatments for a small study that examined the effects of increasing space per bird (8 birds in single- and double-width cages) and the effects of group size (8 and 16 birds in double-width cages); using similar methodologies, these treatments showed differences in egg corticosterone concentrations and evidence of immunosuppression. Together, these data suggest that although furniture when present was well-used, any effects of furniture on hen welfare measured by physical and physiological traits, other than the benefit of a perch on bone strength, were smaller than effects of group size and space allowance.

Characterization of Clade 2.3.2.1 H5N1 Highly Pathogenic Avian Influenza Viruses Isolated from Wild Birds (Mandarin Duck and Eurasian Eagle Owl in 2010 in Korea

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Youn-Jeong Lee

2013-04-01

Full Text Available Starting in late November 2010, the H5N1 highly pathogenic avian influenza (HPAI virus was isolated from many types of wild ducks and raptors and was subsequently isolated from poultry in Korea. We assessed the genetic and pathogenic properties of the HPAI viruses isolated from a fecal sample from a mandarin duck and a dead Eurasian eagle owl, the most affected wild bird species during the 2010/2011 HPAI outbreak in Korea. These viruses have similar genetic backgrounds and exhibited the highest genetic similarity with recent Eurasian clade 2.3.2.1 HPAI viruses. In animal inoculation experiments, regardless of their originating hosts, the two Korean isolates produced highly pathogenic characteristics in chickens, ducks and mice without pre-adaptation. These results raise concerns about veterinary and public health. Surveillance of wild birds could provide a good early warning signal for possible HPAI infection in poultry as well as in humans.

Customs unions, currency crises, and monetary policy coordination: The case of the Eurasian Economic Union

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Evgeny Vinokurov

2017-09-01

Full Text Available After achieving substantial progress in establishing a common customs territory and regulations, customs unions face potential disruptions due to a lack of monetary policy coordination. These disruptions might appear in the form of currency shocks and the ensuing trade conflicts. We approach this issue by looking at the case of the Eurasian Economic Union (EAEU. The volatility of national currencies in 2014–2015 resulted in sizable shifts in competitiveness, culminating in a currency crisis in some member states. This raises the questions of how to gradually achieve a more coordinated monetary policy, what monetary policy options are available, and what would be their relative impact on macroeconomic stability. Using a set of modeling tools and econometric models, we review three monetary regimes, which represent moves from fully independent exchange rate policy through increased policy coordination to joint exchange rate setting.

Diet preference of Eurasian Beaver (Castor Fiber L., 1758 in the environment of Oderské vrchy and its influence on the tree species composition of river bank stands

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Jan Dvořák

2013-01-01

Full Text Available This paper deals with the dietary behaviour and the tree species preference in the river bank stands in the diet of established population Eurasian Beaver (Castor fiber L., 1758 in the environment of Oderské vrchy; the objective is to assess the suitability of this environment for future development of the Eurasian Beaver and to asses the influence of the beaver’s dietary behaviour on the river bank stands. In the monitored area, the total of 5 tree species with the following preference were recorded: willow (Salix 42.2%, aspen (Populus 28%, dogwood (Comus 15.5%, birch (Betula 7.4% and alder (Alnus 6.9%. The most damaged diameter interval recorded within the all damaged tree species ranges from 2.6 to 6 cm, followed by the interval 6.1–12 cm. Over 61% of the trees felled by the beaver had a bigger diameter. The most sensitive reaction to beaver’s dietary behaviour was shown by aspen (reduction of numbers by 27.6% and by willow (reduction of numbers by 16.6% on the monitored area.

Integration Processes on Civil Service Reform in the Eurasian Space

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George A. Borshevskiy

2016-01-01

Full Text Available In the article was studied the process of reforming the institute of civil service in the countries of the Eurasian space (e.g. Russia, Belarus and Kazakhstan. The integration of national systems of public administration and, in particular, the civil service, is an important factor contributing to the implementation of the centripetal tendencies in the post-Soviet space. The research methodology is based on a combination of comparative legal analysis, historical retrospective method, normalization and scaling, structural-functional and system analysis. A comparison of the legal models of public service was made in research. The author puts forward the hypothesis that it is presence the relationship between the quantitative changes (for example, number of employees of civil service and the dynamics of macroeconomic indicators (e.g. number of employed in the economy. In this regard were observed common trends. On materials of the statistical surveys were considered quantitative changes in national systems of civil service. The study of the socio-demographic characteristics of the public service (gender, age, profession allowed to formulate conclusions about the general and specific trends in the reform of the civil service of the analyzed countries. A number of values were first calculated by the author. The work is intended to become the basis for a broad international research on the development of civil service, which is the central mechanism for implementation the integration in the post-Soviet space.

How do colonial Eurasian Griffon Vultures prevent extra-pair mating?

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Joan Bertran

2016-02-01

Full Text Available In colonial breeding species, preventive measures to reduce the risks of extra-pair copulations (EPCs should reflect the actual risk perceived by males (e.g., proximity of neighbors, intrusions into the nest mainly during the fertile period. In colonial vultures, specific studies examining the preventive measures that minimize the risks of EPCs occurring within the competitive context of colonial breeding have not been conducted. Here we tested at Eurasian Griffon Vulture (Gyps fulvus nesting sites the intensity of paternity assurance behavior, shown as frequency and duration of within-pair copulations (WPCs, potential mate vigilance or nest attendance, and levels of aggressivity. This was measured according to the frequency of territorial intrusions and comparison of the fertile vs. the non-fertile period. Our findings suggest that the frequency of WPCs and their duration increased significantly during the presumed fertile period, regarded as the period when Griffon pairs spent significantly more time together at their nests. In addition, low levels of territorial intrusions were observed, an aggressive response of pairs towards intruders, and a relatively high presence of pairs at the nests during the fertile period. Thus, although nesting sites are subject to low exposure to EPC attempts, the increased frequency and duration of copulations during the fertile period suggests that, under pressure from the colonial breeding system, a higher rate of copulations is the most effective preventive mechanism against relative uncertainty of paternity.

Diet of the Eurasian badger (Meles meles in an area of the Italian Prealps

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Monica Marassi

2002-12-01

Full Text Available Abstract Samples of Eurasian badger faeces (n= 147 were collected at monthly intervals from October 1997 to December 1999 in an area of the Italian Prealps (58 km², on the eastern coast of Lario (Como Lake. The altitude of the area ranged from 200 to 1300 m. Badger scats were analysed to estimate the relative volume and the frequency of occurrence of identifiable food items. Fruits, arthropodes, earthworms and mammals constituted the main food categories. Differences were found between the seasonal frequency of occurrences of arthropodes, earthworms and mammals, considering however that the small sample size in summer does not allow any definitive conclusions. The wide range of food items eaten by badgers and the seasonal differences would suggest that the badger is a "generalist" species which adopts an opportunist feeding strategy.

Glacial sequence stratigraphy reveal the Weichselian glacial history of the SE sector of the Eurasian Ice Sheet

Science.gov (United States)

Räsänen, Matti

2016-04-01

Reconstructions of the last Weichselian glacial cycle 117,000-11,700 years (kyr) ago propose that S Finland, adjacent Russia and the Baltic countries in the SE sector of the Eurasian Ice Sheet (EIS), were glaciated during the Middle Weichselian time [marine isotope stage (MIS) 4, 71-57 kyr ago] and that this glaciation was preceded in S Finland by an Early Weichselian interstadial (MIS 5c, 105-93 kyr ago) with pine forest. Here glacial sequence stratigraphy (Powell and Cooper 2002) is applied to isolated Late Pleistocene onshore outcrop sections in S Finland. The analysed sedimentary records have traditionally been investigated, interpreted and published separately by different authors without an attempt to a methodologically more systematic survey. By putting new field data and old observations into a regional sequence stratigraphic framework it is shown how previously unnoticed regularities can be found in the lithofacies and fossil successions. It is shown that the proposed Middle Weichselian glaciation or the pine dominated interstadial did not take place at all (Räsänen et al. 2015). The one Late Weichselian glaciation (MIS 2, 29-11 kyr ago) at the SE sector of EIS was preceded in S Finland by a nearly 90 kyr long still poorly known non-glacial period, featuring tundra with permafrost and probably birch forest. The new Middle Weichselian paleoenvironmental scenario revises the configuration and hydrology of the S part of EIS and gives new setting for the evolution of Scandinavian biota. References Powell, R. D., and Cooper, J. M., 2002, A glacial sequence stratigraphic model for temperate, glaciated continental shelves, in Dowdeswell, J. A., and Cofaig, C. Ó. eds., Glacier-Influenced Sedimentation on High-Latitude Continental Margins: The Geological Society of London, London, Geological Society London, Special Publication v. 203, p. 215-244. Räsänen, M.E., Huitti, J.V., Bhattarai, S. Harvey, J. and Huttunen, S. 2015, The SE sector of the Middle

[On improvement of the mechanism for establishing and changing indicators of quality and food safety in the regulatory and legal acts of the Eurasian Economical Union].

Science.gov (United States)

Arnautov, O V

2016-01-01

In accordance with the Treaty on the Eurasian Economic Union (EAEU) to ensure the sanitary and epidemiological welfare of the population within the Union, a coordinated policy in agreed policy in the sphere of application of sanitary measures is carried out. Sanitary measures are the obligatory requirements and procedures, including requirements for the final product, processing methods, production, transportation, storage and disposal, sampling procedures, methods of research (tests), risk assessment, the state registration, requirements for packaging directly aimed at ensuring the safety of products (goods) in order to protect human welfare, and they should be applied on the basis having a scientific explanation, and only to the extent that is necessary to protect human welfare. Sanitary measures applied within the Union should be based on international and regional standards, guidelines and (or) the recommendations, except when they based on appropriate scientific studies and explanations. In this case sanitary measures which could provide a higher level of sanitary protection are introduced. At present, the mechanism of the development, justification and approval of common sanitary and epidemiological requirements (ESR) and procedures of the Eurasian Economic Commission (the Commission) is not installed. The absence of a clear mechanism for the development, approval and implementation of the ESR to the products (goods) on the basis having a scientific explanation on the one hand could lead to the creation of unjustified barriers to foreign and mutual trade, on the other--to weaken the level of safety for human life and health of products (goods) placed on markets of the Union. In order to bring the regulatory legal acts of the Customs Union in accordance with the Treaty on the Eurasian Economic Union the Commission in cooperation with the competent authorities of the Member States in the field of sanitary and epidemiological welfare developed the project of

Steroid determination in fish plasma using capillary electrophoresis

Science.gov (United States)

Bykova, L.; Archer-Hartmann, S. A.; Holland, L.A.; Iwanowicz, L.R.; Blazer, V.S.

2010-01-01

A capillary separation method that incorporates pH-mediated stacking is employed for the simultaneous determination of circulating steroid hormones in plasma from Perca flavescens (yellow perch) collected from natural aquatic environments. The method can be applied to separate eight steroid standards: progesterone, 17α,20β-dihydroxypregn-4-en-3-one, 17α-hydroxyprogesterone, testosterone, estrone, 11-ketotestosterone, ethynyl estradiol, and 17β-estradiol. Based on screening of plasma, the performance of the analytical method was determined for 17α,20β-dihydroxypregn-4-en-3-one, testosterone, 11-ketotestosterone, and 17β-estradiol. The within-day reproducibility in migration time for these four steroids in aqueous samples was ≤2%. Steroid quantification was accomplished using a calibration curve obtained with external standards. Plasma samples from fish collected from the Choptank and Severn Rivers, Maryland, USA, stored for up to one year were extracted with ethyl acetate and then further processed with anion exchange and hydrophobic solid phase extraction cartridges. The recovery of testosterone and 17β-estradiol from yellow perch plasma was 84 and 85%, respectively. Endogenous levels of testosterone ranged from 0.9 to 44 ng/ml, and when detected 17α,20β-dihydroxypregn-4-en-3-one ranged from 5 to 34 ng/ml. The reported values for testosterone correlated well with the immunoassay technique. Endogenous concentrations of 17β-estradiol were ≤1.7 ng/ml. 11-Ketotestosterone was not quantified because of a suspected interferant. Higher levels of 17α,20β-dihydroxypregn-4-en-3-one were found in male and female fish in which 17β-estradiol was not detected. Monitoring multiple steroids can provide insight into hormonal fluctuations in fish.

Steroid determination in fish plasma using capillary electrophoresis.

Science.gov (United States)

Bykova, Liliya; Archer-Hartmann, Stephanie A; Holland, Lisa A; Iwanowicz, Luke R; Blazer, Vicki S

2010-09-01

A capillary separation method that incorporates pH-mediated stacking is employed for the simultaneous determination of circulating steroid hormones in plasma from Perca flavescens (yellow perch) collected from natural aquatic environments. The method can be applied to separate eight steroid standards: progesterone, 17alpha,20beta-dihydroxypregn-4-en-3-one, 17alpha-hydroxyprogesterone, testosterone, estrone, 11-ketotestosterone, ethynyl estradiol, and 17beta-estradiol. Based on screening of plasma, the performance of the analytical method was determined for 17alpha,20beta-dihydroxypregn-4-en-3-one, testosterone, 11-ketotestosterone, and 17beta-estradiol. The within-day reproducibility in migration time for these four steroids in aqueous samples was < or =2%. Steroid quantification was accomplished using a calibration curve obtained with external standards. Plasma samples from fish collected from the Choptank and Severn Rivers, Maryland, USA, stored for up to one year were extracted with ethyl acetate and then further processed with anion exchange and hydrophobic solid phase extraction cartridges. The recovery of testosterone and 17beta-estradiol from yellow perch plasma was 84 and 85%, respectively. Endogenous levels of testosterone ranged from 0.9 to 44 ng/ml, and when detected 17alpha,20beta-dihydroxypregn-4-en-3-one ranged from 5 to 34 ng/ml. The reported values for testosterone correlated well with the immunoassay technique. Endogenous concentrations of 17beta-estradiol were < or =1.7 ng/ml. 11-Ketotestosterone was not quantified because of a suspected interferant. Higher levels of 17alpha,20beta-dihydroxypregn-4-en-3-one were found in male and female fish in which 17beta-estradiol was not detected. Monitoring multiple steroids can provide insight into hormonal fluctuations in fish. Copyright 2010 SETAC.

Ludvig, Zsuzsa (ed.) Eurasian challenges : partnerships with Russia and other issues of the post-Soviet area. East European Studies, No. 4, Budabest Institute of World Economics and Regional Studies, Hungarian Academy of Sciences, 2013, 163pp. / Csab

Index Scriptorium Estoniae

Weiner, Csaba

2013-01-01

Arvustus: Ludvig, Zsuzsa (ed.) Eurasian challenges : partnerships with Russia and other issues of the post-Soviet area. Budabest Institute of World Economics and Regional Studies, Hungarian Academy of Sciences, 2013

Hierarchical modeling of an invasive spread: The eurasian collared-dove streptopelia decaocto in the United States

Science.gov (United States)

Bled, F.; Royle, J. Andrew; Cam, E.

2011-01-01

Invasive species are regularly claimed as the second threat to biodiversity. To apply a relevant response to the potential consequences associated with invasions (e.g., emphasize management efforts to prevent new colonization or to eradicate the species in places where it has already settled), it is essential to understand invasion mechanisms and dynamics. Quantifying and understanding what influences rates of spatial spread is a key research area for invasion theory. In this paper, we develop a model to account for occupancy dynamics of an invasive species. Our model extends existing models to accommodate several elements of invasive processes; we chose the framework of hierarchical modeling to assess site occupancy status during an invasion. First, we explicitly accounted for spatial structure and how distance among sites and position relative to one another affect the invasion spread. In particular, we accounted for the possibility of directional propagation and provided a way of estimating the direction of this possible spread. Second, we considered the influence of local density on site occupancy. Third, we decided to split the colonization process into two subprocesses, initial colonization and recolonization, which may be ground-breaking because these subprocesses may exhibit different relationships with environmental variations (such as density variation) or colonization history (e.g., initial colonization might facilitate further colonization events). Finally, our model incorporates imperfection in detection, which might be a source of substantial bias in estimating population parameters. We focused on the case of the Eurasian Collared-Dove (Streptopelia decaocto) and its invasion of the United States since its introduction in the early 1980s, using data from the North American BBS (Breeding Bird Survey). The Eurasian Collared-Dove is one of the most successful invasive species, at least among terrestrial vertebrates. Our model provided estimation of the

Quantitative assessment of carbon sequestration reduction induced by disturbances in temperate Eurasian steppe

Science.gov (United States)

Chen, Yizhao; Ju, Weimin; Groisman, Pavel; Li, Jianlong; Propastin, Pavel; Xu, Xia; Zhou, Wei; Ruan, Honghua

2017-11-01

The temperate Eurasian steppe (TES) is a region where various environmental, social, and economic stresses converge. Multiple types of disturbance exist widely across the landscape, and heavily influence carbon cycling in this region. However, a current quantitative assessment of the impact of disturbances on carbon sequestration is largely lacking. In this study, we combined the boreal ecosystem productivity simulator (BEPS), the Shiyomi grazing model, and the global fire model (Glob-FIRM) to investigate the impact of the two major types of disturbance in the TES (i.e. domestic grazing and fire) on regional carbon sequestration. Model performance was validated using satellite data and field observations. Model outputs indicate that disturbance has a significant impact on carbon sequestration at a regional scale. The annual total carbon lost due to disturbances was 7.8 TgC yr-1, accounting for 14.2% of the total net ecosystem productivity (NEP). Domestic grazing plays the dominant role in terrestrial carbon consumption, accounting for 95% of the total carbon lost from the two disturbances. Carbon losses from both disturbances significantly increased from 1999 to 2008 (R 2 = 0.82, P ecosystems.

Methionine supplementation influences melanin-based plumage colouration in Eurasian kestrel, Falco tinnunculus, nestlings.

Science.gov (United States)

Parejo, Deseada; Silva, Nadia

2009-11-01

The extent to which the expression of melanin-based plumage colouration in birds is genetically or environmentally determined is controversial. Here, we performed a between-nest design supplementation with either the sulphur amino acid dl-methionine or with water to investigate the importance of the non-genetic component of melanin-based plumage colouration in the Eurasian kestrel, Falco tinnunculus. Methionine affects growth and immunity, thus we aimed to modify nestling growth and immunity before feather development. Then, we measured the effect of the experiment on colouration of two melanin-based plumage patches of nestling kestrels. We found that methionine slowed down nestling growth through treatment administration and that nestlings compensated by speeding up their growth later. We did not find any effects of methionine on nestling immunity (i.e. lymphocyte counts, natural antibody levels or complement-mediated immunity). Effects on growth seemed to be mirrored by changes in nestling colouration in the two sexes: methionine-nestlings showed less intense brown plumage on their backs compared with control nestlings. These results provide support for a non-genetic determination of a melanin-based plumage patch in the two sexes of nestling kestrels.

Impacts of Snow Darkening by Absorbing Aerosols on Eurasian Climate

Science.gov (United States)

Kim, Kyu-Myong; Lau, William K M.; Yasunari, Teppei J.; Kim, Maeng-Ki; Koster, Randal D.

2016-01-01

The deposition of absorbing aerosols on snow surfaces reduces snow-albedo and allows snowpack to absorb more sunlight. This so-called snow darkening effect (SDE) accelerates snow melting and leads to surface warming in spring. To examine the impact of SDE on weather and climate during late spring and early summer, two sets of NASA GEOS-5 model simulations with and without SDE are conducted. Results show that SDE-induced surface heating is particularly pronounced in Eurasian regions where significant depositions of dust transported from the North African deserts, and black carbon from biomass burning from Asia and Europe occur. In these regions, the surface heating due to SDE increases surface skin temperature by 3-6 degrees Kelvin near the snowline in spring. Surface energy budget analysis indicates that SDE-induced excess heating is associated with a large increase in surface evaporation, subsequently leading to a significant reduction in soil moisture, and increased risks of drought and heat waves in late spring to early summer. Overall, we find that rainfall deficit combined with SDE-induced dry soil in spring provide favorable condition for summertime heat waves over large regions of Eurasia. Increased frequency of summer heat waves with SDE and the region of maximum increase in heat-wave frequency are found along the snow line, providing evidence that early snowmelt by SDE may increase the risks of extreme summer heat wave. Our results suggest that climate models that do not include SDE may significantly underestimate the effect of global warming over extra-tropical continental regions.

Assigning delivered prey to visited habitat : the potential of combining video monitoring at nest and radio telemetry tested on female Eurasian kestrels (Falco tinnunculus)

OpenAIRE

Christensen, Mikkel Emil

2012-01-01

In this study I used a combination of video monitoring and high intensity radio telemetry to assign specific prey items to habitat visited by female Eurasian kestrels (Falco tinnunculus) during the breeding season of 2011 in Trysil, eastern Norway. I used the combined dataset comprising 63 locations reliably paired with prey items taken by five female kestrels to investigate: (1) The probability of a prey item belonging to family Cricetidae and genus Microtus in four observed and four map-der...

Summer co-existence of small-sized cyprinid and percid individuals in natural and impounded stretches of a lowland river: food niche partitioning among fishes.

Science.gov (United States)

Lik, J; Dukowska, M; Grzybkowska, M; Leszczyńska, J

2017-04-01

Due to changes of discharge regime downstream of a dam reservoir, an alluvial natural stretch of the Warta River changed to a macrophyte-dominated ecosystem. Large patches of submersed, aquatic macrophytes appeared in summer and their effect is analysed in this study. These patches contained enriched macroinvertebrate assemblages (epiphyton and benthos) and they were refuge for both zooplankton and young fishes released from the reservoir. Despite these altered conditions in this stretch, roach Rutilus rutilus, perch Perca fluviatilis and ruffe Gymnocephalus cernua dominated, as they did in the natural backwater. Fishes were sampled every 2 weeks from June to August, together with their food resources to assess the partitioning of the diet among small individuals of the three species in both stretches (the natural and affected ones). The aim of the analysis was to answer how animal food associated with water plants was partitioned between the species. In both stretches, G. cernua were primarily benthivorous, but epiphytic fauna, zooplankton and large-sized benthic chironomid larvae replaced lack of many large, benthic insects in the tailwater. Levins' food breath index decreased from 0·36 in the backwater to 0·29 in the tailwater. An opposite trend was observed for P. fluviatilis occurring among macrophytes. Perca fluviatilis were competitors of R. rutilus and took food not only in or on the river bed, but also in the water column. They ate zooplankton and epiphytic fauna and Levins' index increased from 0·32 to 0·44 in the tailwater. Rutilus rutilus fed on adult insects, algae and plant fragments in the natural stretch. In the tailwater, these food types were chiefly complemented by zooplankton. Despite this, the niche breadth of R. rutilus was similar at the two sites. Abundance of food associated with the macrophytes appeared to facilitate cohabitation in the abundant fish populations, but P. fluviatilis appeared to benefit the most in the altered river

Habitat selection by Eurasian lynx (Lynx lynx) is primarily driven by avoidance of human activity during day and prey availability during night.

Science.gov (United States)

Filla, Marc; Premier, Joseph; Magg, Nora; Dupke, Claudia; Khorozyan, Igor; Waltert, Matthias; Bufka, Luděk; Heurich, Marco

2017-08-01

The greatest threat to the protected Eurasian lynx ( Lynx lynx ) in Central Europe is human-induced mortality. As the availability of lynx prey often peaks in human-modified areas, lynx have to balance successful prey hunting with the risk of encounters with humans. We hypothesized that lynx minimize this risk by adjusting habitat choices to the phases of the day and over seasons. We predicted that (1) due to avoidance of human-dominated areas during daytime, lynx range use is higher at nighttime, that (2) prey availability drives lynx habitat selection at night, whereas high cover, terrain inaccessibility, and distance to human infrastructure drive habitat selection during the day, and that (3) habitat selection also differs between seasons, with altitude being a dominant factor in winter. To test these hypotheses, we analyzed telemetry data (GPS, VHF) of 10 lynx in the Bohemian Forest Ecosystem (Germany, Czech Republic) between 2005 and 2013 using generalized additive mixed models and considering various predictor variables. Night ranges exceeded day ranges by more than 10%. At night, lynx selected open habitats, such as meadows, which are associated with high ungulate abundance. By contrast, during the day, lynx selected habitats offering dense understorey cover and rugged terrain away from human infrastructure. In summer, land-cover type greatly shaped lynx habitats, whereas in winter, lynx selected lower altitudes. We concluded that open habitats need to be considered for more realistic habitat models and contribute to future management and conservation (habitat suitability, carrying capacity) of Eurasian lynx in Central Europe.

Influence of the Gulf Stream on the Barents Sea ice retreat and Eurasian coldness during early winter

International Nuclear Information System (INIS)

Sato, Kazutoshi; Inoue, Jun; Watanabe, Masahiro

2014-01-01

Abnormal sea-ice retreat over the Barents Sea during early winter has been considered a leading driver of recent midlatitude severe winters over Eurasia. However, causal relationships between such retreat and the atmospheric circulation anomalies remains uncertain. Using a reanalysis dataset, we found that poleward shift of a sea surface temperature front over the Gulf Stream likely induces warm southerly advection and consequent sea-ice decline over the Barents Sea sector, and a cold anomaly over Eurasia via planetary waves triggered over the Gulf Stream region. The above mechanism is supported by the steady atmospheric response to the diabatic heating anomalies over the Gulf Stream region obtained with a linear baroclinic model. The remote atmospheric response from the Gulf Stream would be amplified over the Barents Sea region via interacting with sea-ice anomaly, promoting the warm Arctic and cold Eurasian pattern. (letter)

The M w = 5.8 14 August 2016 middle Sakhalin earthquake on a boundary between Okhotsk and Eurasian (Amurian) plates

Science.gov (United States)

Konovalov, A. V.; Stepnov, A. A.; Safonov, D. A.; Kozhurin, A. I.; Pavlov, A. S.; Gavrilov, A. V.; Manaychev, K. A.; Tomilev, D. Ye.; Takahashi, H.; Ichiyanagi, M.

2018-04-01

An earthquake with the moment magnitude M w = 5.8 occurred in the middle part of the Sakhalin Island, Russian Federation, on 14 August 2016, at 11:17 a.m. UTC. The earthquake source was located west of the Central Sakhalin Fault Zone, which is considered to mark the boundary between the Okhotsk and Eurasian (Amurian) plates. Moment tensor solution of the mainshock as well as the configuration of aftershock cloud suggests that the earthquake was caused by slip on a SW-dipping reverse fault. For the first time for Sakhalin, we have got the felt reports unified in accordance with DYFI. We also analyzed observed PGA values and, based on them, produced shaking maps.

Feeding behaviour determining differential capture success of evasive prey in underyearling European perch (Perca fluviatilis L.) and roach (Rutilus rutilus (L.))

Czech Academy of Sciences Publication Activity Database

Peterka, Jiří; Matěna, Josef

2011-01-01

Roč. 661, č. 1 (2011), s. 113-121 ISSN 0018-8158 R&D Projects: GA AV ČR(CZ) IAA600170502; GA AV ČR(CZ) KJB600960810 Institutional research plan: CEZ:AV0Z60170517 Keywords : feeding efficiency * attack-distance * repeated strikes * schooling * Daphnia * Cyclops Subject RIV: EH - Ecology, Behaviour Impact factor: 1.784, year: 2011

Should Controls With Respiratory Symptoms Be Excluded From Case-Control Studies of Pneumonia Etiology? Reflections From the PERCH Study.

Science.gov (United States)

Higdon, Melissa M; Hammitt, Laura L; Deloria Knoll, Maria; Baggett, Henry C; Brooks, W Abdullah; Howie, Stephen R C; Kotloff, Karen L; Levine, Orin S; Madhi, Shabir A; Murdoch, David R; Scott, J Anthony G; Thea, Donald M; Driscoll, Amanda J; Karron, Ruth A; Park, Daniel E; Prosperi, Christine; Zeger, Scott L; O'Brien, Katherine L; Feikin, Daniel R

2017-06-15

Many pneumonia etiology case-control studies exclude controls with respiratory illness from enrollment or analyses. Herein we argue that selecting controls regardless of respiratory symptoms provides the least biased estimates of pneumonia etiology. We review 3 reasons investigators may choose to exclude controls with respiratory symptoms in light of epidemiologic principles of control selection and present data from the Pneumonia Etiology Research for Child Health (PERCH) study where relevant to assess their validity. We conclude that exclusion of controls with respiratory symptoms will result in biased estimates of etiology. Randomly selected community controls, with or without respiratory symptoms, as long as they do not meet the criteria for case-defining pneumonia, are most representative of the general population from which cases arose and the least subject to selection bias. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Immunity and fitness in a wild population of Eurasian kestrels Falco tinnunculus

Science.gov (United States)

Parejo, Deseada; Silva, Nadia

2009-10-01

The immune system of vertebrates consists of several components that partly interact and complement each other. Therefore, the assessment of the overall effectiveness of immune defence requires the simultaneous measurement of different immune components. In this study, we investigated intraspecific variability of innate [i.e. natural antibodies (NAb) and complement] and acquired (i.e. leucocyte profiles) immunity and its relationship with fitness correlates (i.e. blood parasite load and reproductive success in adults and body mass and survival until fledging in nestlings) in the Eurasian kestrel Falco tinnunculus. Immunity differed between nestlings and adults and also between adult males and females. Adult kestrels with higher levels of complement were less parasitised by Haemoproteus, and males with higher values of NAbs showed a higher reproductive success. In nestlings, the H/L ratio was negatively related to body mass. Survival until fledging was predicted by all measured immunological variables of nestlings as well as by their fathers' level of complement. This is the first time that innate immunity is linked to survival in a wild bird. Thus, intraspecific variation in different components of immunity predicts variation in fitness prospects in kestrels, which highlights the importance of measuring innate immune components together with components of the acquired immunity in studies assessing the effectiveness of the immune system in wild animals.

Pesticide residues in Nile tilapia (Oreochromis niloticus) and Nile perch (Lates niloticus) from Southern Lake Victoria, Tanzania

International Nuclear Information System (INIS)

Henry, L.; Kishimba, M.A.

2006-01-01

Nile tilapia (Oreochromis niloticus) and Nile perch (Lates niloticus) samples were collected from fish landing stations in nine riparian districts on the Tanzanian side of Lake Victoria and screened for residues of 64 organochlorine, organophosphorus, carbamate, and pyrethroid pesticides. The residue levels in the fish fillet were up to 0.003, 0.03 and 0.2 mg/kg fresh weight (0.7, 3.8 and 42 mg/kg lipid weight) of fenitrothion, DDT and endosulfan, respectively. Mean levels within sites were up to 0.002, 0.02 and 0.1 mg/kg fresh weight (0.5, 0.5 and 16 mg/kg lipid weight), respectively. The detection of higher levels of p,p'-DDT than the degradation products (p,p'-DDD and p,p'-DDE), and higher levels of endosulfan isomers (α and β) than the sulphate, in fish samples, implied recent exposure of fish to DDT and endosulfan, respectively. Generally, most of the fish samples had residue levels above the average method detection limits (MDLs), but were within the calculated ADI. - Fish from Lake Victoria had relatively low pesticide levels

Molecular identification of Taenia spp. in the Eurasian lynx (Lynx lynx) from Finland.

Science.gov (United States)

Lavikainen, A; Haukisalmi, V; Deksne, G; Holmala, K; Lejeune, M; Isomursu, M; Jokelainen, P; Näreaho, A; Laakkonen, J; Hoberg, E P; Sukura, A

2013-04-01

Cestodes of the genus Taenia are parasites of mammals, with mainly carnivores as definitive and herbivores as intermediate hosts. Various medium-sized cats, Lynx spp., are involved in the life cycles of several species of Taenia. The aim of the present study was to identify Taenia tapeworms in the Eurasian lynx (Lynx lynx) from Finland. In total, 135 tapeworms from 72 lynx were subjected to molecular identification based on sequences of 2 mtDNA regions, the cytochrome c oxidase subunit 1 and the NADH dehydrogenase subunit 1 genes. Available morphological characters of the rostellar hooks and strobila were compared. Two species of Taenia were found: T. laticollis (127 samples) and an unknown Taenia sp. (5 samples). The latter could not be identified to species based on mtDNA, and the rostellar hooks were short relative to those described among other Taenia spp. recorded in felids from the Holarctic region. In the phylogenetic analyses of mtDNA sequences, T. laticollis was placed as a sister species of T. macrocystis, and the unknown Taenia sp. was closely related to T. hydatigena and T. regis. Our analyses suggest that these distinct taeniid tapeworms represent a putative new species of Taenia. The only currently recognized definitive host is L. lynx and the intermediate host is unknown.

New evidence for the occurrence of Eurasian lynx (Lynx lynx) in medieval Britain

Science.gov (United States)

Hetherington, David A.; Lord, Tom C.; Jacobi, Roger M.

2006-01-01

The presence of Eurasian lynx as a former native species in Britain during the Holocene is known from bones recovered from several sites. AMS radiocarbon dating of lynx bone recovered from two sites in the Craven area of northern England gave 1842 +/- 35 14C yr BP and 1550 +/- 24 14C yr BP, together representing the youngest dates for lynx from England, and in the case of the latter, the youngest for Britain as a whole. These dates support the view that the game animal whose occurrence in the nearby Lake District is described in the early 7th century Cumbric text Pais Dinogad, and whose translation to date has been problematic, is a lynx. The occurrence of lynx in early medieval Britain shows that earlier periods of climate change, previously blamed for the species' extinction in Britain, were not responsible. Instead, anthropogenic factors such as severe deforestation, declining deer populations, and persecution, are likely to have caused the extirpation of lynx in Britain. Consequently, the lynx qualifies as a candidate for reintroduction. Large-scale reafforestation, the growth of deer populations, and more positive attitudes towards carnivores in modern society, could permit the restoration of lynx to Britain, particularly in Scotland.

Influence of tourism and traffic on the Eurasian lynx hunting activity and daily movements

Directory of Open Access Journals (Sweden)

Belotti, E.

2012-01-01

Full Text Available Human presence influences survival of large carnivores in several ways and even outdoor activities can be a source of disturbance. As ungulate prey provide the Eurasian lynx (Lynx lynx with food for several nights and the pattern of lynx activity is mainly shaped by searching for and consuming large prey, the need to move decreases strongly while the prey is eaten. However, during the day, human activity may drive lynx to move to safe shelters and habitat features such as dense vegetation may increase tolerance. In the Bohemian Forest (Czech Republic, we found 116 prey killed by five GPS–collared lynxes. We tested whether the kill sites were located farther from roads or tourist trails than a set of randomly generated locations and whether presence of roads or tourist trails and habitat structure influenced the distance ‘kill site to daytime resting sites’. At night, with low human activity, lynxes did not avoid roads and even selected the surroundings of tourist trails. The distance ‘kill site to daytime resting sites’ correlated negatively with presence of habitat concealment and distance to tourist trails, suggesting that outdoor activities may have to be considered in lynx management plans.

The Fifth International Conference “Dialogue of Urban and Steppe Cultures on the Eurasian Space”, ad memoriam G.A. Fyodorov-Davydov

Directory of Open Access Journals (Sweden)

Zeleneev Yuriy A.

2012-03-01

Full Text Available The Fifth International Conference "Dialogue of Urban and Steppe Cultures on the Eurasian Space", dedicated to the memory of G. A. Fyodorov-Davydov, was held in the village of Selitrennoye, Astrakhan oblast, in October 2011. For the 10 years of holding these conferences, a range of constantly debated issues has formed. To these refer problems as: the steppes of Eurasia from the Early Iron Age through to the Middle Ages; relations of the Golden Horde with the outside world; medieval numismatics; natural science and combined statistics methods in archaeology. The contributions were mainly centered on these issues. The materials of the conference were published as a collection of articles.

From "Duck Factory" to "Fish Factory": Climate induced changes in vertebrate communities of prairie pothole wetlands and small lakes

Science.gov (United States)

McLean, Kyle I.; Mushet, David M.; Stockwell, Craig A.

2016-01-01

The Prairie Pothole Region’s myriad wetlands and small lakes contribute to its stature as the “duck factory” of North America. The fishless nature of the region’s aquatic habitats, a result of frequent drying, freezing, and high salinity, influences its importance to waterfowl. Recent precipitation increases have resulted in higher water levels and wetland/lake freshening. In 2012–13, we sampled chemical characteristics and vertebrates (fish and salamanders) of 162 Prairie Pothole wetlands and small lakes. We used non-metric multidimensional scaling, principal component analysis, and bootstrapping techniques to reveal relationships. We found fish present in a majority of sites (84 %). Fish responses to water chemistry varied by species. Fathead minnows (Pimephales promelas) and brook sticklebacks (Culaea inconstans) occurred across the broadest range of conditions. Yellow perch (Perca flavescens) occurred in a smaller, chemically defined, subset. Iowa darters (Etheostoma exile) were restricted to the narrowest range of conditions. Tiger salamanders (Ambystoma mavortium) rarely occurred in lakes with fish. We also compared our chemical data to similar data collected in 1966–1976 to explore factors contributing to the expansion of fish into previously fishless sites. Our work contributes to a better understanding of relationships between aquatic biota and climate-induced changes in this ecologically important area.

Otoliths as recorders of palaeoenvironments: comparison of radiocarbon age and isoleucine epimerization in Pleistocene golden perch 'Macquaria ambigua' otoliths from Willandra Lakes

International Nuclear Information System (INIS)

Kalish, J.M.; Pritchard, C.; Miller, G.H.; Rosewater, A.

1997-01-01

Fish otoliths form by the accretion of layers of calcium carbonate and organic-rich material that often form distinctive layers over time scales ranging from days to years. These layers are not resorbed during the life of the fish and have potential to provide data relevant to both the biology of the fish and the environment to which the fish has been exposed. Environmental variability based on otoliths can be estimated through measures of stable oxygen isotopes, trace elements, and the widths of both daily and annual increments. Although otoliths can be dated based on measurement of radiocarbon by accelerator mass spectrometry this method is relatively expensive. An alternative method for dating golden perch otoliths is based on measurements of isoleucine D/L ratios. Miller and Rosewater (1995) demonstrated that golden perch otoliths are near a perfect closed system for racemization and that otoliths have potential of dating surrounding sediments older than 100 ka. Despite the suitability of these structures for racemization measurements, many of collections of Pleistocene otoliths from Willandra Lakes are not appropriate for determination of sample age. Most otoliths sampled in the region have been derived from surface collections, while it is recommended that samples should have been buried at least 1 m during most of their history. Therefore, the majority of existing otolith collections are not appropriate for geochronology or palaeothermometry. Nevertheless, when used in conjunction with radiocarbon dates, racemization data may be of value in assessing the relationship among otoliths in an assemblage. Radiocarbon ages and isoleucine D/L ratios were determined for 30 otoliths collected from Willandra Lakes. The rostrum of each otolith was analysed for D/L ratios and a portion of the posterior of the same otolith was analysed for radiocarbon by accelerator mass spectrometry. Sample weights for both analyses ranged from 14.0 to 25.6 mg. The central portion of the

North America-Greenland-Eurasian relative motions: implications for circum-arctic tectonic reconstructions

Energy Technology Data Exchange (ETDEWEB)

Rowley, D.B.; Lottes, A.L.; Ziegler, A.M.

1985-02-01

The Mesozoic-Cenozoic tectonic evolution of the Circum-Arctic region is based on constraints imposed by (1) relative motion histories of the three major plates (North America, Greenland, and Eurasia) and a number of smaller pieces, and (2) distribution and age of sutures, accretionary prisms, volcanic arcs, fold-thrust belts, stretched continental crust, strike-slip faults, and ocean floor. The authors conclude that: (1) North America and Eurasia remained relatively fixed to each other until the latest Cretaceous-Paleocene opening of the Labrador Sea-Baffin Bay and Greenland-Norwegian and Eurasian basins (earlier convergence between North America and Eurasia in the Bering Sea region shown on many reconstructions are artifacts of incorrect plate reconstructions); (2) the North Slope-Seward-Chukotka block has constituted an isthmus connection between North America and northeast Asia since at least the middle Paleozoic and did not rotate away from the Canadian Arctic; (3) the Canada basin opened behind a clockwise-rotating Alpha Cordillera-Mendeleyev ridge arc during the Early to middle Cretaceous and consumed older, Paleozoic(.) Makarov basin ocean floor (the Chukchi cap is a detached continental fragment derived from the Beaufort Sea; the North Slope Arctic margin is a left-lateral transform fault associated with the opening of the Canada basin); and (4) the Nares Strait fault has a net relative displacement of approximately 25 km, but actual motion between Greenland and northern Ellesmere was about 250 km of strongly transpressive motion that resulted in the Eurekan and Svalbardian orogenies.

Influence of high-latitude warming and land-use changes in the early 20th century northern Eurasian CO2 sink

Science.gov (United States)

Bastos, Ana; Peregon, Anna; Gani, Érico A.; Khudyaev, Sergey; Yue, Chao; Li, Wei; Gouveia, Célia M.; Ciais, Philippe

2018-06-01

While the global carbon budget (GCB) is relatively well constrained over the last decades of the 20th century [1], observations and reconstructions of atmospheric CO2 growth rate present large discrepancies during the earlier periods [2]. The large uncertainty in GCB has been attributed to the land biosphere, although it is not clear whether the gaps between observations and reconstructions are mainly because land-surface models (LSMs) underestimate inter-annual to decadal variability in natural ecosystems, or due to inaccuracies in land-use change reconstructions. As Eurasia encompasses about 15% of the terrestrial surface, 20% of the global soil organic carbon pool and constitutes a large CO2 sink, we evaluate the potential contribution of natural and human-driven processes to induce large anomalies in the biospheric CO2 fluxes in the early 20th century. We use an LSM specifically developed for high-latitudes, that correctly simulates Eurasian C-stocks and fluxes from observational records [3], in order to evaluate the sensitivity of the Eurasian sink to the strong high-latitude warming occurring between 1930 and 1950. We show that the LSM with improved high-latitude phenology, hydrology and soil processes, contrary to the group of LSMs in [2], is able to represent enhanced vegetation growth linked to boreal spring warming, consistent with tree-ring time-series [4]. By compiling a dataset of annual agricultural area in the Former Soviet Union that better reflects changes in cropland area linked with socio-economic fluctuations during the early 20th century, we show that land-abadonment during periods of crisis and war may result in reduced CO2 emissions from land-use change (44%–78% lower) detectable at decadal time-scales. Our study points to key processes that may need to be improved in LSMs and LUC datasets in order to better represent decadal variability in the land CO2 sink, and to better constrain the GCB during the pre-observational record.

Total mercury and mercury species in birds and fish in an aquatic ecosystem in the Czech Republic

International Nuclear Information System (INIS)

Houserova, Pavlina; Kuban, Vlastimil; Kracmar, Stanislav; Sitko, Jilji

2007-01-01

Total mercury and mercury species (methylmercury-MeHg, inorganic mercury - Hg 2+ ) were determined in the aquatic ecosystem Zahlinice (Czech Republic). Four tissues (muscle, intestines, liver and kidney) of three bird species - cormorant, great crested grebe and Eurasian buzzard, muscle tissues of common carp, grass carp, northern pike, goldfish, common tench, perch and rudd, aquatic plants (reed mace and common reed), sediments and water were analysed. Relative contents of MeHg (of total Hg) were in the range from 71% to 94% and from 15% up to 62% in the muscle and intestines and in liver, respectively, for all birds. Statistically significant differences were found between contents of MeHg in liver tissues of young and adult cormorant populations (F 4.6 = 56.71, P -5 ). Relative contents of MeHg in muscle tissues of fishes were in the range from 65.1% to 87.9% of total Hg. - The distribution of the mercury species among the organs of the individual birds is discussed

Individual diet has sex-dependent effects on vertebrate gut microbiota

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Bolnick, Daniel I.; Snowberg, Lisa K.; Hirsch, Philipp E.; Lauber, Christian L.; Org, Elin; Parks, Brian; Lusis, Aldons J.; Knight, Rob; Caporaso, J. Gregory; Svanbäck, Richard

2014-01-01

Vertebrates harbour diverse communities of symbiotic gut microbes. Host diet is known to alter microbiota composition, implying that dietary treatments might alleviate diseases arising from altered microbial composition (‘dysbiosis’). However, it remains unclear whether diet effects are general or depend on host genotype. Here we show that gut microbiota composition depends on interactions between host diet and sex within populations of wild and laboratory fish, laboratory mice and humans. Within each of two natural fish populations (threespine stickleback and Eurasian perch), among-individual diet variation is correlated with individual differences in gut microbiota. However, these diet–microbiota associations are sex dependent. We document similar sex-specific diet–microbiota correlations in humans. Experimental diet manipulations in laboratory stickleback and mice confirmed that diet affects microbiota differently in males versus females. The prevalence of such genotype by environment (sex by diet) interactions implies that therapies to treat dysbiosis might have sex-specific effects. PMID:25072318

New Details of the Eurasian Beaver’s, Castor Fiber (Rodentia, Castoridae, Expansion in the Lowland Part of Transcarpathia, Ukraine

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Barkasi Z.

2016-12-01

Full Text Available The present paper contains information on a new beaver colony discovered in the Chornyi mochar tract, which is located in the lowland part of Transcarpathia (= Zakarpattia Region. This rodent species disappeared from the territory of Transcarpathia most likely in the 18th century. Its first reappearance was recorded in 2003. Since, the Eurasian beaver has demonstrated a rapid expansion, primarily along the main rivers. The discovered by us colony allows to suggest that the beaver is continuing its dispersal, entering far into the main river’s tributaries and other shallower water bodies. Consequently, we are witnessing not only the expansion of the species’ geographical range, but also the enlargement of the number of habitat types occupied by the animal. The possibilities and supposed consequences of the species’ further expansion within the tract are shown as well.

The Investigation of the European and Eurasian Markets for Technologies: Ukraine in Regional Patent Spaces

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Grytsulenko Svitlana I.

2017-05-01

Full Text Available The exclusive right to intellectual property acts as a universally recognized tool of the modern competitive struggle for the markets for goods and technologies, which actualizes the issue of Ukraine’s participation in this process. For this purpose, based on the data from the European, Eurasian and world patent statistics, the article measures the level of inventive activity of Ukraine in the nearest regional markets for technologies. Among the relevant quantitative and qualitative indicators for the evaluation of the patenting in Ukraine and leading countries of Europe and Eurasia there analyzed: the total volume and dynamics of filing patent applications; the total volume and specific weight of patent portfolios; the high-tech patenting. Based on the results of the study, the corresponding conclusions are drawn. In particular, the huge gap between Ukraine and leaders of inventive activity predetermined the absence of any significant influence of the country on the development of innovative markets in Europe and Eurasia. The decrease in Ukraine’s striving to succeed in the above mentioned ones leads to the loss of both promising markets and entire sectors of the national economy.

Pesticide residues in Nile tilapia (Oreochromis niloticus) and Nile perch (Lates niloticus) from Southern Lake Victoria, Tanzania

Energy Technology Data Exchange (ETDEWEB)

Henry, L. [Chemistry Department, University of Dar es Salaam. PO Box 35061, Dar es Salaam (Tanzania); Kishimba, M.A. [Chemistry Department, University of Dar es Salaam. PO Box 35061, Dar es Salaam (Tanzania)]. E-mail: kishimba@chem.udsm.ac.tz

2006-03-15

Nile tilapia (Oreochromis niloticus) and Nile perch (Lates niloticus) samples were collected from fish landing stations in nine riparian districts on the Tanzanian side of Lake Victoria and screened for residues of 64 organochlorine, organophosphorus, carbamate, and pyrethroid pesticides. The residue levels in the fish fillet were up to 0.003, 0.03 and 0.2 mg/kg fresh weight (0.7, 3.8 and 42 mg/kg lipid weight) of fenitrothion, DDT and endosulfan, respectively. Mean levels within sites were up to 0.002, 0.02 and 0.1 mg/kg fresh weight (0.5, 0.5 and 16 mg/kg lipid weight), respectively. The detection of higher levels of p,p'-DDT than the degradation products (p,p'-DDD and p,p'-DDE), and higher levels of endosulfan isomers ({alpha} and {beta}) than the sulphate, in fish samples, implied recent exposure of fish to DDT and endosulfan, respectively. Generally, most of the fish samples had residue levels above the average method detection limits (MDLs), but were within the calculated ADI. - Fish from Lake Victoria had relatively low pesticide levels.

Converging migration routes of Eurasian hobbies Falco subbuteo crossing the African equatorial rain forest.

Science.gov (United States)

Strandberg, Roine; Klaassen, Raymond H G; Hake, Mikael; Olofsson, Patrik; Alerstam, Thomas

2009-02-22

Autumn migration of adult Eurasian hobbies Falco subbuteo from Europe to southern Africa was recorded by satellite telemetry and observed routes were compared with randomly simulated routes. Two non-random features of observed routes were revealed: (i) shifts to more westerly longitudes than straight paths to destinations and (ii) strong route convergence towards a restricted area close to the equator (1 degree S, 15 degrees E). The birds migrated south or southwest to approximately 10 degrees N, where they changed to south-easterly courses. The maximal spread between routes at 10 degrees N (2134 km) rapidly decreased to a minimum (67 km) close to the equator. We found a striking relationship between the route convergence and the distribution of continuous rainforest, suggesting that hobbies minimize flight distance across the forest, concentrating in a corridor where habitat may be more suitable for travelling and foraging. With rainforest forming a possible ecological barrier, many migrants may cross the equator either at 15 degrees E, similar to the hobbies, or at 30-40 degrees E, east of the rainforest where large-scale migration is well documented. Much remains to be understood about the role of the rainforest for the evolution and future of the trans-equatorial Palaearctic-African bird migration systems.

Radiocesium (137Cs) from the Chernobyl reactor in Eurasian woodcock and earthworms in Norway

International Nuclear Information System (INIS)

Kalas, J.A.; Bretten, S.; Njastad, O.; Byrkjedal, I.

1994-01-01

To understand the ecological effects of the Chernobyl reactor accident, we investigated radiocesium ( 137 Cs) levels in Eurasian woodcock (Scolopax rusticola), earthworms (Lambricidae), litter (dead organic materials lying on the ground), humus (beneath litter 2 cm deep), and mineral soil samples (3-6 cm deep) from a heavily effected (20-60 kBq/m 2 [1 Bq = 1 nuclear fission/sec]) area in Norway. The highest concentrations measured in earthworms (1988 median = 142 Bq/Kg) and woodcock (1986 median = 730 Bq/kg) for human food (600 Bq/kg fresh mass) only were found in woodcock during 1986. Radiocesium concentrations decreased (P < 0.001) in earthworms (40%) and woodcock (95%) from 1986 to 1990. There was no reduction in total radiocesium in soil over the same period. The relatively high radiocesium concentrations in woodcock during 1986 and the decreasing radiocesium ratio in woodcock to earthworms during the first years following fallout could have been caused by woodcock ingesting abiotic radiocesium with earthworms. The decrease in radiocesium in woodcock and earthworms during the study (1986-90) probably resulted from decreasing bioavailability of radiocesium during the first years after fallout rather than by radiocesium disappearing from the ecosystem. 38 refs., 3 figs., 2 tabs

Legal basis for risk analysis methodology while ensuring food safety in the Eurasian Economic union and the Republic of Belarus

Directory of Open Access Journals (Sweden)

E.V. Fedorenko

2015-09-01

Full Text Available Health risk analysis methodology is an internationally recognized tool for ensuring food safety. Three main elements of risk analysis are risk assessment, risk management and risk communication to inform the interested parties on the risk, are legislated and implemented in the Eurasian Economic Union and the Republic of Belarus. There is a corresponding organizational and functional framework for the application of risk analysis methodology as in the justification of production safety indicators and the implementation of public health surveillance. Common methodological approaches and criteria for evaluating public health risk are determined, which are used in the development and application of food safety requirements. Risk assessment can be used in justifying the indicators of safety (contaminants, food additives, and evaluating the effectiveness of programs on enrichment of food with micronutrients.

Rapid Global River Flood Risk Assessment under Climate and Socioeconomic Scenarios: An Extreme Case of Eurasian region

Science.gov (United States)

Kwak, Young-joo; Magome, Jun; Hasegawa, Akira; Iwami, Yoichi

2017-04-01

Causing widespread devastation with massive economic damage and loss of human lives, flood disasters hamper economic growth and accelerate poverty particularly in developing countries. Globally, this trend will likely continue due to increase in flood magnitude and lack of preparedness for extreme events. In line with risk reduction efforts since the early 21st century, the monitors and governors of global river floods should pay attention to international scientific and policy communities for support to facilitate evidence-based policy making with a special interest in long-term changes due to climate change and socio-economic effects. Although advanced hydrological inundation models and risk models have been developed to reveal flood risk, hazard, exposure, and vulnerability at a river basin, it is obviously hard to identify the distribution and locations of continent-level flood risk based on national-level data. Therefore, we propose a methodological possibility for rapid global flood risk assessment with the results from its application to the two periods, i.e., Present (from 1980 to 2004) and Future (from 2075 to 2099). The method is particularly designed to effectively simplify complexities of a hazard area by calculating the differential inundation depth using GFID2M (global flood inundation depth 2-dimension model), despite low data availability. In this research, we addressed the question of which parts in the Eurasian region (8E to 180E, 0N to 60N) can be found as high-risk areas in terms of exposed population and economy in case of a 50-year return period flood. Economic losses were estimated according to the Shared Socioeconomic Pathways (SSP) scenario, and the flood scale was defined using the annual maximum daily river discharge under the extreme conditions of climate change simulated with MRI-AGCM3.2S based on the Representative Concentration Pathways (RCP8.5) emissions scenario. As a preliminary result, the total potential economic loss in the

Piagetian object permanence and its development in Eurasian jays (Garrulus glandarius).

Science.gov (United States)

Zucca, Paolo; Milos, Nadia; Vallortigara, Giorgio

2007-04-01

Object permanence in Eurasian jays (Garrulus glandarius) was investigated using a complete version of the Uzgiris and Hunt scale 1. Nine hand-raised jays were studied, divided into two groups according to their different developmental stages (experiment 1, older jays: 2-3 months old, n = 4; experiment 2, younger jays: 15 days old, n = 5). In the first experiment, we investigated whether older jays could achieve piagetian stage 6 of object permanence. Tasks were administered in a fixed sequence (1-15) according to the protocols used in other avian species. The aim of the second experiment was to check whether testing very young jays before their development of "neophobia" could influence the achievement times of piagetian stages. Furthermore, in this experiment tasks were administered randomly to investigate whether the jays' achievement of stage 6 follows a fixed sequence related to the development of specific cognitive abilities. All jays tested in experiments 1 and 2 fully achieved piagetian stage 6 and no "A not B" errors were observed. Performance on visible displacement tasks was better than performance on invisible ones. The results of experiment 2 show that "neophobia" affected the response of jays in terms of achievement times; the older jays in experiment 1 took longer to pass all the tasks when compared with the younger, less neophobic, jays in experiment 2. With regard to the achieving order, jays followed a fixed sequence of acquisition in experiment 2, even if tasks were administered randomly, with the exception of one subject. The results of these experiments support the idea that piagetian stages of cognitive development exist in avian species and that they progress through relatively fixed sequences.

Differences in spatial communities of European perch (Perca fluviatilis Linnaeus, 1758) fry in a canyon-shaped reservoir are not attributable to genetics

Czech Academy of Sciences Publication Activity Database

Kalous, L.; Kuříková, P.; Kohout, J.; Rylková, K.; Petrtýl, M.; Čech, Martin

2017-01-01

Roč. 33, č. 2 (2017), s. 306-313 ISSN 0175-8659. [European Congress of Ichthyology /15./. Porto, 07.09.2015-11.09.2015] R&D Projects: GA ČR GA206/06/1371; GA ČR GP206/09/P266; GA MŠk(CZ) 7F14316 Institutional support: RVO:60077344 Keywords : diel vertical migration * cross-species amplification * dna-sequence data * postglacial colonization * microsatellite loci Subject RIV: GL - Fishing OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 0.845, year: 2016

Formation of perched lava ponds on basaltic volcanoes: Interaction between cooling rate and flow geometry allows estimation of lava effusion rates

Science.gov (United States)

Wilson, L.; Parfitt, E. A.

1993-01-01

Perched lava ponds are infrequent but distinctive topographic features formed during some basaltic eruptions. Two such ponds, each approximately 150 m in diameter, formed during the 1968 eruption at Napau Crater and the 1974 eruption of Mauna Ulu, both on Kilauea Volcano, Hawaii. Each one formed where a channelized, high volume flux lava flow encountered a sharp reduction of slope: the flow spread out radially and stalled, forming a well-defined terminal levee enclosing a nearly circular lava pond. We describe a model of how cooling limits the motion of lava spreading radially into a pond and compare this with the case of a channelized flow. The difference in geometry has a major effect, such that the size of a pond is a good indicator of the volume flux of the lava forming it. Lateral spreading on distal shallow slopes is a major factor limiting the lengths of lava flows.

Supplementation of lactobacilli improves growth, regulates microbiota composition and suppresses skeletal anomalies in juvenile pike-perch (Sander lucioperca) reared in recirculating aquaculture system (RAS): A pilot study.

Science.gov (United States)

Ljubobratovic, Uros; Kosanovic, Dejana; Vukotic, Goran; Molnar, Zsuzsanna; Stanisavljevic, Nemanja; Ristovic, Tijana; Peter, Geza; Lukic, Jovanka; Jeney, Galina

2017-12-01

This research aimed to test the effects of lactobacilli, applied to cultured pike-perch, either through hydrolyzed OTOHIME fish diet, or through Artemia nauplii, on fish growth, microbiota balance and skeletal development. On the 12th Day Post Hatching (DPH) fish were divided into following treatment groups: two groups received the combination of OTOHIME and nauplii enriched either with Lactobacillus paracasei BGHN14+Lactobacillus rhamnosus BGT10 or with Lactobacillus reuteri BGGO6-55+Lactobacillus salivarius BGHO1, and one group received OTOHIME hydrolyzed by BGHN14+BGT10 and non-enriched nauplii. Control group received non-enriched nauplii and non-hydrolyzed OTOHIME. The treatment lasted 14days and fish were sacrificed on the 26th DPH for the assessment of digestive enzyme activity and microbiota composition. Individual total lengths and individual body weights were recorded at the end of the treatments, on the 26th DPH, and also on the 45th DPH, in parallel with the evaluation of skeletal deformities and fish survival. Our results indicated positive effect of Artemia enriched with BGGO6-55+BGHO1 on fish growth, skeletal development and trypsin to chymotrypsin activity ratio (T/C), as an indicator of protein digestibility. Hydrolysis of OTOHIME was also associated with better skeletal development, higher T/C values and lower levels of Aeromonas and Mycobacterium spp., which are important fish pathogens. Though additional testing in larger cohort studies is needed, these observations are promising in terms of usage of probiotics for improved environmentally friendly production of pike-perch in Recirculating Aquaculture System (RAS). Copyright © 2017 Elsevier Ltd. All rights reserved.

Desire-state attribution: Benefits of a novel paradigm using the food-sharing behavior of Eurasian jays (Garrulus glandarius).

Science.gov (United States)

Ostojić, Ljerka; Cheke, Lucy G; Shaw, Rachael C; Legg, Edward W; Clayton, Nicola S

2016-01-01

In recent years, we have investigated the possibility that Eurasian jay food sharing might rely on desire-state attribution. The female's desire for a particular type of food can be decreased by sating her on it (specific satiety) and the food sharing paradigm can be used to test whether the male's sharing pattern reflects the female's current desire. Our previous findings show that the male shares the food that the female currently wants. Here, we consider 3 simpler mechanisms that might explain the male's behavior: behavior reading, lack of self-other differentiation and behavioral rules. We illustrate how we have already addressed these issues and how our food sharing paradigm can be further adapted to answer outstanding questions. The flexibility with which the food sharing paradigm can be applied to rule out alternative mechanisms makes it a useful tool to study desire-state attribution in jays and other species that share food.

Natural selection among Eurasians at genomic regions associated with HIV-1 control

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Allison David B

2011-06-01

Full Text Available Abstract Background HIV susceptibility and pathogenicity exhibit both interindividual and intergroup variability. The etiology of intergroup variability is still poorly understood, and could be partly linked to genetic differences among racial/ethnic groups. These genetic differences may be traceable to different regimes of natural selection in the 60,000 years since the human radiation out of Africa. Here, we examine population differentiation and haplotype patterns at several loci identified through genome-wide association studies on HIV-1 control, as determined by viral-load setpoint, in European and African-American populations. We use genome-wide data from the Human Genome Diversity Project, consisting of 53 world-wide populations, to compare measures of FST and relative extended haplotype homozygosity (REHH at these candidate loci to the rest of the respective chromosome. Results We find that the Europe-Middle East and Europe-South Asia pairwise FST in the most strongly associated region are elevated compared to most pairwise comparisons with the sub-Saharan African group, which exhibit very low FST. We also find genetic signatures of recent positive selection (higher REHH at these associated regions among all groups except for sub-Saharan Africans and Native Americans. This pattern is consistent with one in which genetic differentiation, possibly due to diversifying/positive selection, occurred at these loci among Eurasians. Conclusions These findings are concordant with those from earlier studies suggesting recent evolutionary change at immunity-related genomic regions among Europeans, and shed light on the potential genetic and evolutionary origin of population differences in HIV-1 control.

Deglaciation of the Eurasian ice sheet complex

Science.gov (United States)

Patton, Henry; Hubbard, Alun; Andreassen, Karin; Auriac, Amandine; Whitehouse, Pippa L.; Stroeven, Arjen P.; Shackleton, Calvin; Winsborrow, Monica; Heyman, Jakob; Hall, Adrian M.

2017-08-01

The Eurasian ice sheet complex (EISC) was the third largest ice mass during the Last Glacial Maximum with a span of over 4500 km and responsible for around 20 m of eustatic sea-level lowering. Whilst recent terrestrial and marine empirical insights have improved understanding of the chronology, pattern and rates of retreat of this vast ice sheet, a concerted attempt to model the deglaciation of the EISC honouring these new constraints is conspicuously lacking. Here, we apply a first-order, thermomechanical ice sheet model, validated against a diverse suite of empirical data, to investigate the retreat of the EISC after 23 ka BP, directly extending the work of Patton et al. (2016) who modelled the build-up to its maximum extent. Retreat of the ice sheet complex was highly asynchronous, reflecting contrasting regional sensitivities to climate forcing, oceanic influence, and internal dynamics. Most rapid retreat was experienced across the Barents Sea sector after 17.8 ka BP when this marine-based ice sheet disintegrated at a rate of ∼670 gigatonnes per year (Gt a-1) through enhanced calving and interior dynamic thinning, driven by oceanic/atmospheric warming and exacerbated by eustatic sea-level rise. From 14.9 to 12.9 ka BP the EISC lost on average 750 Gt a-1, peaking at rates >3000 Gt a-1, roughly equally partitioned between surface melt and dynamic losses, and potentially contributing up to 2.5 m to global sea-level rise during Meltwater Pulse 1A. Independent glacio-isostatic modelling constrained by an extensive inventory of relative sea-level change corroborates our ice sheet loading history of the Barents Sea sector. Subglacial conditions were predominately temperate during deglaciation, with over 6000 subglacial lakes predicted along with an extensive subglacial drainage network. Moreover, the maximum EISC and its isostatic footprint had a profound impact on the proglacial hydrological network, forming the Fleuve Manche mega-catchment which had an area of �

Year-class formation of upper St. Lawrence River northern pike

Science.gov (United States)

Smith, B.M.; Farrell, J.M.; Underwood, H.B.; Smith, S.J.

2007-01-01

Variables associated with year-class formation in upper St. Lawrence River northern pike Esox lucius were examined to explore population trends. A partial least-squares (PLS) regression model (PLS 1) was used to relate a year-class strength index (YCSI; 1974-1997) to explanatory variables associated with spawning and nursery areas (seasonal water level and temperature and their variability, number of ice days, and last day of ice presence). A second model (PLS 2) incorporated four additional ecological variables: potential predators (abundance of double-crested cormorants Phalacrocorax auritus and yellow perch Perca flavescens), female northern pike biomass (as a measure of stock-recruitment effects), and total phosphorus (productivity). Trends in adult northern pike catch revealed a decline (1981-2005), and year-class strength was positively related to catch per unit effort (CPUE; R2 = 0.58). The YCSI exceeded the 23-year mean in only 2 of the last 10 years. Cyclic patterns in the YCSI time series (along with strong year-classes every 4-6 years) were apparent, as was a dampening effect of amplitude beginning around 1990. The PLS 1 model explained over 50% of variation in both explanatory variables and the dependent variable, YCSI first-order moving-average residuals. Variables retained (N = 10; Wold's statistic ??? 0.8) included negative YCSI associations with high summer water levels, high variability in spring and fall water levels, and variability in fall water temperature. The YCSI exhibited positive associations with high spring, summer, and fall water temperature, variability in spring temperature, and high winter and spring water level. The PLS 2 model led to positive YCSI associations with phosphorus and yellow perch CPUE and a negative correlation with double-crested cormorant abundance. Environmental variables (water level and temperature) are hypothesized to regulate northern pike YCSI cycles, and dampening in YCSI magnitude may be related to a

Seasonal and interannual effects of hypoxia on fish habitat quality in central Lake Erie

Science.gov (United States)

Arend, Kristin K.; Beletsky, Dmitry; DePinto, Joseph; Ludsin, Stuart A.; Roberts, James J.; Rucinski, Daniel K.; Scavia, Donald; Schwab, David J.; Höök, Tomas O.

2011-01-01

1. Hypoxia occurs seasonally in many stratified coastal marine and freshwater ecosystems when bottom dissolved oxygen (DO) concentrations are depleted below 2–3 mg O2 L-1. 2. We evaluated the effects of hypoxia on fish habitat quality in the central basin of Lake Erie from 1987 to 2005, using bioenergetic growth rate potential (GRP) as a proxy for habitat quality. We compared the effect of hypoxia on habitat quality of (i) rainbow smelt, Osmerus mordax mordax Mitchill (young-of-year, YOY, and adult), a cold-water planktivore, (ii) emerald shiner, Notropis atherinoides Rafinesque (adult), a warm-water planktivore, (iii) yellow perch, Perca flavescens Mitchill (YOY and adult), a cool-water benthopelagic omnivore and (iv) round goby Neogobius melanostomus Pallas (adult) a eurythermal benthivore. Annual thermal and DO profiles were generated from 1D thermal and DO hydrodynamics models developed for Lake Erie’s central basin. 3. Hypoxia occurred annually, typically from mid-July to mid-October, which spatially and temporally overlaps with otherwise high benthic habitat quality. Hypoxia reduced the habitat quality across fish species and life stages, but the magnitude of the reduction varied both among and within species because of the differences in tolerance to low DO levels and warm-water temperatures. 4. Across years, trends in habitat quality mirrored trends in phosphorus concentration and water column oxygen demand in central Lake Erie. The per cent reduction in habitat quality owing to hypoxia was greatest for adult rainbow smelt and round goby (mean: -35%), followed by adult emerald shiner (mean: -12%), YOY rainbow smelt (mean: -10%) and YOY and adult yellow perch (mean: -8.5%). 5. Our results highlight the importance of differential spatiotemporally interactive effects of DO and temperature on relative fish habitat quality and quantity. These effects have the potential to influence the performance of individual fish species as well as population dynamics

Biota monitoring under the Water Framework Directive: On tissue choice and fish species selection.

Science.gov (United States)

Fliedner, Annette; Rüdel, Heinz; Lohmann, Nina; Buchmeier, Georgia; Koschorreck, Jan

2018-04-01

The study addresses the topic of suitable matrices for chemical analysis in fish monitoring and discusses the effects of data normalization in the context of the European Water Framework Directive (WFD). Differences between species are considered by comparing three frequently monitored species of different trophic levels, i.e., chub (Squalius cephalus, n = 28), (bream, Abramis brama, n = 11), and perch (Perca fluviatilis, n = 19) sampled in the German Danube. The WFD priority substances dioxins, furans and dioxin-like polychlorinated biphenyls (PCDD/F + dl-PCB), polybrominated diphenyl ethers (PBDE), α-hexabromocyclododecane (α-HBCDD), hexachlorobenzene (HCB), mercury (Hg), and perfluorooctane sulfonic acid (PFOS) as well as non-dioxin-like (ndl)-PCB were analyzed separately in fillet and carcass and whole body concentrations were calculated. Hg was analyzed in individual fish fillets and carcasses, all other substances were determined in pool samples, which were compiled on the basis of fish size (3 chub pools, 1 bream pool, 2 perch pools). The data were normalized to 5% lipid weight (or 26% dry mass in the case of Hg and PFOS) for comparison between matrices and species. Hg concentrations were generally higher in fillet than in whole fish (mean whole fish-to-fillet ratio: 0.7) whereas all other substances were mostly higher in whole fish. In the case of lipophilic substances these differences leveled after lipid normalization. Significant correlations (p ≤ .05) were detected between Hg and fish weight and age. Hg concentrations varied least among younger fish. PCDD/F, dl-PCB, ndl-PCB, PBDE, α-HBCDD and HCB correlated significantly (p ≤ .05) with lipid concentrations. Fillet-to-whole fish conversion equations and/or conversion factors were derived for all substances except α-HCBDD. Although more data also for individual fish would be desirable the results are nevertheless a step on the way to translate fillet concentrations of priority

The Eurasian ice sheet reinforces the East Asian summer monsoon during the interglacial 500 000 years ago

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Qiuzhen Yin

2008-05-01

Full Text Available Deep-sea and ice-core records show that interglacial periods were overall less "warm" before about 420 000 years ago than after, with relatively higher ice volume and lower greenhouse gases concentration. This is particularly the case for the interglacial Marine Isotope Stage 13 which occurred about 500 000 years ago. However, by contrast, the loess and other proxy records from China suggest an exceptionally active East Asian summer monsoon during this interglacial. A three-dimension Earth system Model of Intermediate complexity was used to understand this seeming paradox. The astronomical forcing and the remnant ice sheets present in Eurasia and North America were taken into account in a series of sensitivity experiments. Expectedly, the seasonal contrast is larger and the East Asian summer monsoon is reinforced compared to Pre-Industrial time when Northern Hemisphere summer is at perihelion. Surprisingly, the presence of the Eurasian ice sheet was found to reinforce monsoon, too, through a south-eastwards perturbation planetary wave. The trajectory of this wave is influenced by the Tibetan plateau.

Change in diet of the Eurasian eagle owl (Bubo bubo suggests decline in biodiversity in Wadi Al Makhrour, Bethlehem Governorate, Palestinian Territories

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Amr Zuhair S.

2016-12-01

Full Text Available The diet of the Eurasian eagle owl (Bubo bubo was studied in Wadi Al Makhrour, Bethlehem, Palestinian Territories in 2015 with fresh and several year old pellets. Three species of arthropods, one reptile species, at least four bird species, and six species of mammals were recovered from the studied pellets. Black rat (Rattus rattus was the most common prey (37.0%, followed by the southern white-breasted hedgehog (Erinaceus concolor (29.4% and birds (21.8%. Comparison of recent and older pellets showed change in diet composition. Recent pellets contained more Rattus rattus compared to older ones. Older pellets included more naturally-occurring species such as Meriones tristrami, Microtus guentheri, and Rousettus aegyptiacus, which were absent in newer pellets.

Genetic structure and evidence for recent population decline in Eurasian otter populations in the Czech and Slovak Republics: implications for conservation

DEFF Research Database (Denmark)

Hájková, P.; Pertoldi, C.; Ukendt, Zemanová

2007-01-01

Over the latter part of the 20th century, Eurasian otter Lutra lutra populations suffered dramatic declines, resulting in extinction or fragmentation of populations in many western and central European countries. Part of the Czech otter population became totally isolated while the Slovak populati...... that they remain a strongly protected species in both countries. The spreading and re-connection of otter populations observed recently is essential for the future health of the populations, and should be supported through habitat conservation......., suggesting that the strongest decline probably occurred between the 1970s and the mid-1990s. The results of this study confirm that otter populations remain vulnerable to any violent demographic change and, despite the claims of fish-farmers and anglers for legal culls, it is highly desirable...

Selection of perching site background color by Hamadryas feronia (Lepidoptera: Nymphalidae) in Costa Rica: implications for industrial melanism.

Science.gov (United States)

Murillo-Hiller, Luis Ricardo

2012-09-01

Observations of the increased frequency of melanic forms in moths of the genus Biston in Great Britain after the industrial revolution lead to the development of the theory of Industrial Melanism. Nonetheless, arguments against that interpretation of the experimental evidence have polarized acceptance of the concept. New evidence based on diurnal butterflies is more credible because it involves behavior that can be seen in action, during daylight, and because the natural history of the selected species is well known. An experiment was carried out in which three substrate colors (white, black, and gray) were employed to test the landing preferences of Hamadryas feronia. A marked preference was observed for landing on white and gray, and a chi-square (N=644 tests) showed evidence of a preference by males to land on white, and for females to land on gray. Black was rejected perhaps because it provides very little background matching with the butterfly's colors. The butterfly habit of perching selectively on particular color substrates is a genetically fixed behavior, where the males possibly choose white as a tactic to be noticed by females and attract them, whereas females prefer gray to enhance crypsis and avoid attracting predators.

Reference-free SNP discovery for the Eurasian beaver from restriction site-associated DNA paired-end data.

Science.gov (United States)

Senn, Helen; Ogden, Rob; Cezard, Timothee; Gharbi, Karim; Iqbal, Zamin; Johnson, Eric; Kamps-Hughes, Nick; Rosell, Frank; McEwing, Ross

2013-06-01

In this study, we used restriction site-associated DNA (RAD) sequencing to discover SNP markers suitable for population genetic and parentage analysis with the aim of using them for monitoring the reintroduction of the Eurasian beaver (Castor fibre) to Scotland. In the absence of a reference genome for beaver, we built contigs and discovered SNPs within them using paired-end RAD data, so as to have sufficient flanking region around the SNPs to conduct marker design. To do this, we used a simple pipeline which catalogued the Read 1 data in stacks and then used the assembler cortex_var to conduct de novo assembly and genotyping of multiple samples using the Read 2 data. The analysis of around 1.1 billion short reads of sequence data was reduced to a set of 2579 high-quality candidate SNP markers that were polymorphic in Norwegian and Bavarian beaver. Both laboratory validation of a subset of eight of the SNPs (1.3% error) and internal validation by confirming patterns of Mendelian inheritance in a family group (0.9% error) confirmed the success of this approach. © 2013 John Wiley & Sons Ltd.

The full annual carbon balance of Eurasian boreal forests is highly sensitive to precipitation

Science.gov (United States)

Öquist, Mats; Bishop, Kevin; Grelle, Achim; Klemedtsson, Leif; Köhler, Stephan; Laudon, Hjalmar; Lindroth, Anders; Ottosson Löfvenius, Mikaell; Wallin, Marcus; Nilsson, Mats

2013-04-01

Boreal forest biomes are identified as one of the major sinks for anthropogenic atmospheric CO2 and are also predicted to be particularly sensitive to climate change. Recent advances in understanding the carbon balance of these biomes stems mainly from eddy-covariance measurements of the net ecosystem exchange (NEE). However, NEE includes only the vertical CO2 exchange driven by photosynthesis and ecosystem respiration. A full net ecosystem carbon balance (NECB) also requires inclusion of lateral carbon export (LCE) through catchment discharge. Currently LCE is often regarded as negligible for the NECB of boreal forest ecosystems of the northern hemisphere, commonly corresponding to ~5% of annual NEE. Here we use long term (13 year) data showing that annual LCE and NEE are strongly correlated (p=0.003); years with low C sequestration by the forest coincide with years when lateral C loss is high. The fraction of NEE lost annually through LCE varied markedly from solar radiation caused by clouds. The dual effect of precipitation implies that both the observed and the predicted increases in annual precipitation at high latitudes may reduce NECB in boreal forest ecosystems. Based on regional scaling of hydrological discharge and observed spatio-temporal variations in forest NEE we conclude that our finding is relevant for large areas of the boreal Eurasian landscape.

The SE sector of the Middle Weichselian Eurasian Ice Sheet was much smaller than assumed

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Räsänen, Matti E.; Huitti, Janne V.; Bhattarai, Saroj; Harvey, Jerry; Huttunen, Sanna

2015-08-01

Quaternary climatic and glacial history must be known in order to understand future environments. Reconstructions of the last Weichselian glacial cycle 117,000-11,700 years (kyr) ago propose that S Finland, adjacent Russia and the Baltic countries in the SE sector of the Eurasian Ice Sheet (EIS), were glaciated during the Middle Weichselian time [marine isotope stage (MIS) 4, 71-57 kyr ago] and that this glaciation was preceded in S Finland by an Early Weichselian interstadial (MIS 5c, 105-93 kyr ago) with pine forest. We apply glacial sequence stratigraphy to isolated Late Pleistocene onshore outcrop sections and show, that these events did not take place. The one Late Weichselian glaciation (MIS 2, 29-11 kyr ago) was preceded in S Finland by a nearly 90 kyr non-glacial period, featuring tundra with permafrost and probably birch forest. Our new Middle Weichselian paleoenvironmental scenario revises the configuration and hydrology of the S part of EIS and gives new setting for the evolution of Scandinavian biota. If future development during the coming glacial cycle proves to be similar, the high-level nuclear waste stored in the bedrock of SW Finland should be located deeper than currently planned, i.e. below any possible future permafrost.

Explaining individual- and country-level variations in unregistered employment using a multi-level model: evidence from 35 Eurasian countries

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Krasniqi Besnik A.

2017-12-01

Full Text Available The aim of this paper is to evaluate the individual- and country-level variations in unregistered employment. To analyse whether it is marginalised groups who are more likely to engage in unregistered employment and explain the country-level variations, a 2010 Life in Transition Survey (LiTS involving 38,864 interviews in 35 Eurasian countries is reported. Multilevel logistic regression analysis reveals that younger age groups, the divorced, and those with fewer years in education, are more likely to be unregistered employed. On a country-level, meanwhile, the prevalence of unregistered employment is strongly associated with tax morale; the greater the asymmetry between informal and formal institutions, the greater is the prevalence of unregistered employment. It is also higher when GDP per capita as well as social distribution and state intervention (subsidies and transfers, social contribution expenditure, health expenditure are lower. The paper concludes by discussing the theoretical and policy implications.

Fish assemblage structure and habitat associations in a large western river system

Science.gov (United States)

Smith, C.D.; Quist, Michael C.; Hardy, R. S.

2016-01-01

Longitudinal gradients of fish assemblage and habitat structure were investigated in the Kootenai River of northern Idaho. A total of 43 500-m river reaches was sampled repeatedly with several techniques (boat-mounted electrofishing, hoop nets and benthic trawls) in the summers of 2012 and 2013. Differences in habitat and fish assemblage structure were apparent along the longitudinal gradient of the Kootenai River. Habitat characteristics (e.g. depth, substrate composition and water velocity) were related to fish assemblage structure in three different geomorphic river sections. Upper river sections were characterized by native salmonids (e.g. mountain whitefish Prosopium williamsoni), whereas native cyprinids (peamouth Mylocheilus caurinus, northern pikeminnow Ptychocheilus oregonensis) and non-native fishes (pumpkinseed Lepomis gibbosus, yellow perch Perca flavescens) were common in the downstream section. Overall, a general pattern of species addition from upstream to downstream sections was discovered and is likely related to increased habitat complexity and additions of non-native species in downstream sections. Assemblage structure of the upper sections were similar, but were both dissimilar to the lower section of the Kootenai River. Species-specific hurdle regressions indicated the relationships among habitat characteristics and the predicted probability of occurrence and relative abundance varied by species. Understanding fish assemblage structure in relation to habitat could improve conservation efforts of rare fishes and improve management of coldwater river systems.

Population models of burrowing mayfly recolonization in Western Lake Erie

Science.gov (United States)

Madenjian, C.P.; Schloesser, D.W.; Krieger, K.A.

1998-01-01

Burrowing mayflies, Hexagenia spp. (H. limbata and H. rigida), began recolonizing western Lake Erie during the 1990s. Survey data for mayfly nymph densities indicated that the population experienced exponential growth between 1991 and 1997. To predict the time to full recovery of the mayfly population, we fitted logistic models, ranging in carrying capacity from 600 to 2000 nymphs/m2, to these survey data. Based on the fitted logistic curves, we forecast that the mayfly population in western Lake Erie would achieve full recovery between years 1998 and 2000, depending on the carrying capacity of the western basin. Additionally, we estimated the mortality rate of nymphs in western Lake Erie during 1994 and then applied an age-based matrix model to the mayfly population. The results of the matrix population modeling corroborated the exponential growth model application in that both methods yielded an estimate of the population growth rate, r, in excess of 0.8 yr-1. This was the first evidence that mayfly populations are capable of recolonizing large aquatic ecosystems at rates comparable with those observed in much smaller lentic ecosystems. Our model predictions should prove valuable to managers of power plant facilities along the western basin in planning for mayfly emergences and to managers of the yellow perch (Perca flavescens) fishery in western Lake Erie.