69 research outputs found

    Cephalopods in the diet of keystone-species animals in the region of the Argentine Islands Archipelago (West Antarctica)

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    Оbjective. The study of diet of keystone-species vertebrates (Nothotenia coriiceps, Phalacrocorax bransfieldensis, Leptonychotes weddellii) in the ecosystem of the Argentine Islands Archipelago.Дослідження трофічних зв’язків ключових видів хребетних тварин (Nothotenia coriiceps, Phalacrocorax bransfieldensis, Leptonychotes weddellii) екосистеми Аргентинських островів. Завданням було з’ясувати, видовий склад і який відсоток становлять головоногі молюски в їхньому живленні

    Allocation of the diet of the Argentine Islands’ inshore ichthyofauna

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    Fish diets are important indicators of ecosystem change. This aspect of the ichthyofauna of the coast of the Argentine Islands has been insufficiently studied in comparison with other regions. This article presents the results of comparison of dietary and somatic parameters of the dominant species Notothenia coriiceps depending on the point, depth and season of catch. The sample was collected between February 2006 and February 2007. In the year of study, N. coriiceps, Trematomus bernacchii, Chaenocephalus aceratus (common species), Harpagifer antarcticus and Pagothenia borchgrevinki (rare species in this region) were caught. The average fish size in this region does not differ from other places in the Southern Ocean. In Cornice Channel and Stella Creek, N. coriiceps was smaller than at other points due to the narrowness and shallow depth of these places. In winter, large individuals apparently migrated from the coast. The diet of N. coriiceps consisted mainly of crustaceans and seaweeds, with a small number of mollusks (especially limpets), which are common. The number of fish in the diet of N. coriiceps is relatively low for this region. Access to food was relatively the same at different points and depths of the catch. The lowest amount of food was in the fall, the highest amount of food was in the spring and summer. The condition and hepatosomatic index also did not change depending on the point and depth of the catch, but they were low in spring and high in summer. Perhaps this is due to the low energy value of food, which is not compensated by the amount. It is necessary to conduct studies of the diet of N. coriiceps in other years to clarify the specificity of fish in the diet and phenological changes in somatic parameters. Similar studies are needed for other species in the region if catches are sufficient to collect a representative sample

    Diet of Long-Eared Owl and Common Kestrel in an Urban Landscape (Ukraine)

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    In the present study we performed a comparative dietary analysis of two predatory birds, the Long-eared Owl (Asio otus) and the Common Kestrel (Falco tinnunculus) in the district of Lviv city. We found that the Long-eared Owl and the Common Kestrel are typical small mammal specialists within the urban ecosystem. Considering the abundance and biomass of prey, small mammals comprise 98.4% of the Long-eared Owl’s diet. The species composition of mammals coincides almost 50% in the food intake comparison of the two birds. It has been established that the main prey of both species is the Common Vole (Microtus arvalis). The diet of the Common Kestrel is more varied, compared to the Long-eared Owl, due to the consumption of different species of insects (families Gryllotalpidae, Tettigoniidae, Carabidae and Scarabaeidae), reptiles and birds. This result suggested that dietary plasticity of the Common Kestrel facilitate successful adaptation to the urban landscape. The Long-eared Owl is more narrowly specialized in feeding on murine rodents, which reduces the trophic competition between the two predatory birds and allows the coexistence of two predators in the urban ecosystem

    Features of Chronology and Breeding Success of Pygoscelis papua and P.аdeliae (Spheniscidae) Penguins in the Wilhelm Archipelago (CCAMLR Subarea 48.1)

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    Objective. To investigate the qualitative changes in the habitats of two most common species penguin populations in the Wilhelm Archipelago Pygoscelis papua and P. adeliae (Spheniscidae) penguins in the CCAMLR Subarea 48.1 under the impact of climate changes and krill fishery.Мета. Дослідити якісні зміни в оселищах двох найпоширеніших видів пінгвінів на архіпелазі Вільгельма Pygoscelis papua та P. adeliae (Spheniscidae) у підрайоні CCAMLR 48.1 під впливом зміни клімату та промислу криля

    Wolf outside, dog inside? The genomic make-up of the Czechoslovakian Wolfdog

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    Background Genomic methods can provide extraordinary tools to explore the genetic background of wild species and domestic breeds, optimize breeding practices, monitor and limit the spread of recessive diseases, and discourage illegal crossings. In this study we analysed a panel of 170k Single Nucleotide Polymorphisms with a combination of multivariate, Bayesian and outlier gene approaches to examine the genome-wide diversity and inbreeding levels in a recent wolf x dog cross-breed, the Czechoslovakian Wolfdog, which is becoming increasingly popular across Europe. Results Pairwise FST values, multivariate and assignment procedures indicated that the Czechoslovakian Wolfdog was significantly differentiated from all the other analysed breeds and also well-distinguished from both parental populations (Carpathian wolves and German Shepherds). Coherently with the low number of founders involved in the breed selection, the individual inbreeding levels calculated from homozygosity regions were relatively high and comparable with those derived from the pedigree data. In contrast, the coefficient of relatedness between individuals estimated from the pedigrees often underestimated the identity-by-descent scores determined using genetic profiles. The timing of the admixture and the effective population size trends estimated from the LD patterns reflected the documented history of the breed. Ancestry reconstruction methods identified more than 300 genes with excess of wolf ancestry compared to random expectations, mainly related to key morphological features, and more than 2000 genes with excess of dog ancestry, playing important roles in lipid metabolism, in the regulation of circadian rhythms, in learning and memory processes, and in sociability, such as the COMT gene, which has been described as a candidate gene for the latter trait in dogs. Conclusions In this study we successfully applied genome-wide procedures to reconstruct the history of the Czechoslovakian Wolfdog, assess individual wolf ancestry proportions and, thanks to the availability of a well-annotated reference genome, identify possible candidate genes for wolf-like and dog-like phenotypic traits typical of this breed, including commonly inherited disorders. Moreover, through the identification of ancestry-informative markers, these genomic approaches could provide tools for forensic applications to unmask illegal crossings with wolves and uncontrolled trades of recent and undeclared wolfdog hybrids

    Population dynamics and spatial distribution of large carnivores in the Ukrainian Carpathians and Polissya

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    Large carnivores play an important role as indicators of the state of the natural ecosystems. The analysis of the number and distribution of large carnivores (brown bear – Ursos arctos, Eurasian lynx – Lynx lynx and grey wolf – Canis lupus) was established in the Ukrainian Carpathians and Ukrainian Polissya. Annual data on the number of large carnivores on the territories of hunting units and nature conservation areas from 2009 to 2019 was summarized. To analyze the number and distribution of large carnivores in the Ukrainian Carpathians, data from 4 regions were taken into account, namely Lviv, Zakarpattia, Ivano-Frankivsk and Chernivtsi regions. To analyze the number and distribution of large carnivores in Ukrainian Polissya, data from 6 regions were taken into account – Volyn, Rivne, Zhytomyr, Kyiv, Chernihiv and Sumy regions. According to official data obtained from hunting units and nature conservation areas in 2019, there were 375 bears, 435 lynxes and 563 wolves in the Ukrainian Carpathians; and 4 bears, 128 lynxes and 609 wolves in Ukrainian Polissya. Based on the collected data, the maps of the distribution of large carnivores in the Ukrainian Carpathians and Ukrainian Polissya were created in the format of a grid of squares of 10 by 10 km (cell size 100 km²), namely – density maps of populations of large carnivores, as well as maps of forest habitats of large carnivores. The obtained results provided a better understanding of the dynamics of large carnivores over the last decade in terms of regions, as well as the density of populations of large carnivores in certain areas and their distribution areas in the Ukrainian Carpathians and Ukrainian Polissya. However, the summary results of the number of individuals obtained based on official reports of hunting units and nature conservation areas are overestimated due to the problem of "double" accounting of animals by users of adjacent lands (hunting units, nature conservation areas). Therefore, it is important to establish synchronization of accounting between users of adjacent lands (nature protection areas, forestries, etc.), to use unified research methods, and to exchange monitoring data and information between institutions of different state subordination. Such scientifically based data are the basis for the development and implementation of measures for the conservation and management of large carnivore populations at the regional, national and international levels

    Phylogeographic history of grey wolves in Europe

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    Background: While it is generally accepted that patterns of intra-specific genetic differentiation are substantially affected by glacial history, population genetic processes occurring during Pleistocene glaciations are still poorly understood. In this study, we address the question of the genetic consequences of Pleistocene glaciations for European grey wolves. Combining our data with data from published studies, we analysed phylogenetic relationships and geographic distribution of mitochondrial DNA haplotypes for 947 contemporary European wolves. We also compared the contemporary wolf sequences with published sequences of 24 ancient European wolves. Results: We found that haplotypes representing two haplogroups, 1 and 2, overlap geographically, but substantially differ in frequency between populations from south-western and eastern Europe. A comparison between haplotypes from Europe and other continents showed that both haplogroups are spread throughout Eurasia, while only haplogroup 1 occurs in contemporary North American wolves. All ancient wolf samples from western Europe that dated from between 44,000 and 1,200 years B.P. belonged to haplogroup 2, suggesting the long-term predominance of this haplogroup in this region. Moreover, a comparison of current and past frequencies and distributions of the two haplogroups in Europe suggested that haplogroup 2 became outnumbered by haplogroup 1 during the last several thousand years. Conclusions: Parallel haplogroup replacement, with haplogroup 2 being totally replaced by haplogroup 1, has been reported for North American grey wolves. Taking into account the similarity of diets reported for the late Pleistocene wolves from Europe and North America, the correspondence between these haplogroup frequency changes may suggest that they were associated with ecological changes occurring after the Last Glacial Maximum

    Antarctic bdelloid rotifers: diversity, endemism and evolution

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    Antarctica is an isolated continent whose conditions challenge the survival of living organisms. High levels of endemism are now known in many Antarctic organisms, including algae, tardigrades, nematodes and microarthropods. Bdelloid rotifers are a key, widespread and abundant group of Antarctic microscopic invertebrates. However, their diversity, regional distribution and endemism have received little attention until recently. We provide the first authoritative review on Antarctic Bdelloidea, based on published data and new collections. Our analysis reveals the extreme levels of bdelloid endemism in Antarctica. Sixty-six bdelloid morphospecies are now confirmed from the continent, and 83–91 putative species are identified using molecular approaches (depending on the delimitation method used). Twelve previously unknown species are described based on both morphology and molecular analyses. Molecular analyses indicate that only two putative species found in Antarctica proved to be truly cosmopolitan. The level of endemism based on the available data set (95%) is higher than that in any other continent, with many bdelloid species occurring only in maritime or continental Antarctica. These findings are consistent with the long-term presence of Bdelloidea in Antarctica, with their considerable isolation facilitating intraregional radiation, providing further evidence that does not support the microbial global ubiquity hypothesis that “everything is everywhere.

    Assessment of the corrosion resistance of the main alternative materials for light water reactors tolerant fuel rod cladding

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    Basic materials for nuclear fuel rod claddings (Zr+1%Nb and E110 alloys), as well as alternative materials for tolerant fuel rod claddings (Cr18Ni10Тi steel and 42CrNiМo alloy), that are able to maximally prevent the development of severe accidents at nuclear power plants were tested in the high-temperature water vapor environment. A comparative analysis of the corrosion resistance of these materials is presented, as well as the results of similar tests by the world’s leading scientists. Samples of 42CrNiМo alloy revealed the highest corrosion resistance at high temperatures in a water vapor environment among the alternative materials for the fuel rod cladding considered in the study. The corrosion resistance of this alloy at a temperature of 1200 °C is approximately 40 times higher than that of Cr18Ni10Тi steel and E110 alloy. The high-temperature corrosion rate of the 42CrNiМo alloy is comparable to the corrosion rate of the Fechral alloy. The hydrogen that would be released during the oxidation of the 42CrNiМo alloy claddings would be almost forty times less compared to the zirconium alloy under the conditions of severe design accidents associated with overheating of the core.Проведено високотемпературні дослідження в середовищі водяної пари базових матеріалів оболонок ядерного палива (сплави Zr+1%Nb та Е110), а також альтернативних матеріалів оболонок толерантного палива (сталі Х18Н10Т та 42ХНМ), які здатні максимально перешкоджати розвитку важких аварій на АЕС. Представлено порівняльний аналіз корозійної стійкості цих матеріалів, а також результати подібних випробувань світових провідних вчених. Із розглянутих у роботі альтернативних матеріалів оболонки твел найбільш високу корозійну стійкість при високих температурах у середовищі водяної пари показали зразки сплаву 42ХНМ. Корозійна стійкість цього сплаву при температурі 1200 °С приблизно в 40 разів вища, ніж сталі Х18Н10Т та сплаву Е110. Швидкість високотемпературної корозії сплаву 42ХНМ співставна зі швидкістю корозії сплаву фехраль. В умовах максимальних проектних аварій, пов’язаних з перегрівом активної зони, кількість водню, який виділиться при окисненні оболонок, виготовлених зі сплаву 42ХНМ, буде майже в 40 разів менше в порівнянні з цирконієвим сплавом
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