183 research outputs found

    New Paratethyan dwarf baleen whales mark the origin of cetotheres

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    Background Family Cetotheriidae sensu stricto and several closely related taxa comprise the Cetotherioidea and represent a lineage of Neogene baleen whales that includes the smallest edentulous baleen whales in Earth history. Most of known cetotheriids came from the Late Miocene to Quaternary, and the earliest records from the latest Middle Miocene. The Paratethys region shows a great diversity of Middle to Late Miocene cetotheriids. That includes nominative taxon of the family, Cetotherium rathkii, and this suggests that the earliest cetotheriids may have lived in that region. Materials and methods Here, Ciuciulea davidi, a new genus and species from the Middle Miocene of southeastern Europe, is described as the chronologically earliest and earliest diverging member of Cetotheriidae. Also, a new specimen of Otradnocetus, a basal Cetotherioidea sensu Gol’din & Steeman, 2015 is identified from the Late Miocene deposits of Caucasus and compared with Otradnocetus virodovi from the Middle Miocene of the same region. Results and discussion Ciuciulea davidi is a dwarf whale displaying primitive traits: posterior ends of facial bones forming a single transverse line, a narrow occipital shield, and a relatively long interparietal region. Meanwhile, it shares some cetotheriid apomorphies: posteriorly telescoped wedge-shaped facial bones and an ovoid tympanic bulla with shallow lateral and medial furrows, a short anterior lobe and a short sigmoid process. Phylogenetic analysis suggests that Parietobalaena and Otradnocetus are branches diverging before the clade Cetotheriidae + Neobalaenidae. This is confirmed by the stepwise evolution of the anatomy of the squamosal, mandible, and ear bones across these groups. The re-described juvenile specimen of Otradnocetus differs from O. virodovi in the more primitive anatomy of the mandible and the autapomorphic anatomy of the humerus. Records of the earliest cetotheriids and related taxa in the Paratethys support the idea that this could be the region where Cetotheriidae evolved before their worldwide dispersal and radiation

    Body Proportions of Harbour Porpoise Phocoena phocoena (Cetacea, Phocoenidae) in the Sea of Azov and the Black Sea

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    Исследования относительного роста частей тела морской свиньи впервые показали, что он в постнатальном онтогенезе существенно различается в четырех секторах, соответствующих черепу и отделам позвоночника. Наибольшими темпами относительного роста отличаются грудной и хвостовой отделы. Средняя часть тела отличается наибольшими темпами относительного роста у обоих полов. Выдвинута гипотеза о том, что двухстадийный рост организма определяется периодичностью роста хвостового отдела. Половой диморфизм размеров тела создается за счет частей тела, проявляющих положительную аллометрию или изометрию у обоих полов, однако различия в абсолютных величинах затрагивают лишь анально-генитальное расстояние.The studies of the allometric growth of the body parts in harbour porpoises have shown that the growth of body parts during the postnatal ontogenesis of the harbour porpoise differs substantially in four body sectors, which correspond to the skull and the parts of vertebral column. The highest rates of allometric growth are observed in the thoracic and caudal departments. The middle part of the body is characterized by maximum rates of allometry in both sexes. The hypothisis was brought forward that the two-stage growth of the organism is determined by the periodicity of growth of the caudal department. Sexual dimorphism of the body size is determined by the body parts, which exhibit positive allometry or isometry in both part. Sexual differences in growth rates are observed in the lumbar part but the differences of absolute length values concern only anusgenital distance

    Genetic homogeneity in the face of morphological heterogeneity in the harbor porpoise from the Black Sea and adjacent waters (<i>Phocoena phocoena relicta</i>)

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    Absence of genetic differentiation is usually taken as an evidence of panmixia, but can also reflect other situations, including even nearly complete demographic independence among large-sized populations. Deciphering which situation applies has major practical implications (e.g., in conservation biology). The endangered harbor porpoises in the Black Sea illustrates this point well. While morphological heterogeneity suggested that population differentiation may exist between individuals from the Black and Azov seas, no genetic study provided conclusive evidence or covered the entire subspecies range. Here, we assessed the genetic structure at ten microsatellite loci and a 3904 base-pairs mitochondrial fragment in 144 porpoises across the subspecies range (i.e., Aegean, Marmara, Black, and Azov seas). Analyses of the genetic structure, including F ST, Bayesian clustering, and multivariate analyses revealed a nearly complete genetic homogeneity. Power analyses rejected the possibility of underpowered analyses (power to detect F ST ≥ 0.008 at microsatellite loci). Simulations under various demographic models, evaluating the evolution of F ST, showed that a time-lag effect between demographic and genetic subdivision is also unlikely. With a realistic effective population size of 1000 individuals, the expected “gray zone” would be at most 20 generations under moderate levels of gene flow (≤10 migrants per generation). After excluding alternative hypotheses, panmixia remains the most likely hypothesis explaining the genetic homogeneity in the Black Sea porpoises. Morphological heterogeneity may thus reflect other processes than population subdivision (e.g., plasticity, selection). This study illustrates how combining empirical and theoretical approaches can contribute to understanding patterns of weak population structure in highly mobile marine species. </p

    Prehistoric and historic exploitation of marine mammals in the Black Sea

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    The recent exploitation of marine species is relatively well documented and understood in terms of impacts on species abundance, distribution, and resource use. In contrast, ancient exploitation of marine mammals remains poorly documented; in part, because a detailed meta-analysis of their presence in the zooarchaeological record is lacking. This is true in the Black Sea, where cetaceans are reported in the zooarchaeological record but have not yet been studied comprehensively. Here, we synthesize all available published and unpublished zooarchaeological data from 27 sites around the Black Sea, dating from the Mesolithic and Neolithic periods (6500-6000 BCE) to the Medieval period (641–1475 CE), to document the extent and nature of the exploitation of the Black Sea cetacean species. The results suggest that cetacean exploitation was practised continuously in the Black Sea over a period of 8500 years from the Neolithic through to the Medieval period. This suggests a much longer history of marine mammal exploitation in the Black Sea than previously understood, pushing back the timeline of human impacts on the Black Sea marine fauna.</p

    Диагностические и прогностические возможности электрохимических измерений редокс потенциала плазмы крови

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    Aims: Determination of operating characteristics of the test based on blood plasma redox potential monitoring in patients with different pathological conditions associated with impaired oxygen metabolism during treatment in postoperative period and expanding the range of parameters of the developed method of investigation of blood plasma redox potential.Methods: It were examined healthy volunteers group as following group (n =63), groups of patients with transplanted liver (n =64), kidney (n =59), and lungs (n =7). Redox potential measurements were done by platinum electrode, reference electrode was silver-chlorine one. Potentiostate IPC-ProL was used to registrate and record a dependence redox potential via time. Time of measurement was 15 min.Results: statistically significant differencees of redox potentials ranges was found in healthy volunteers and patients with transplanted kidney and liver. Ratio of measured redox potentials coincident with the values within the confidence interval in healthy volunteers was 12% in patients with transplanted kidney and 10% in patients with transplanted liver. We observed significant differences in the nature of changes of blood plasma's redox potential values in course of monitoring of subgroups of patients with and without complications after liver transplantation. It was found that sensitivity of electrochemical method was 85%, selectivity — 69,8%, precision — 85,2%.Conclusion: we discovered value ranges of blood plasma redox potential typical for different pathological states; we detected an interaction between the effect of treatment and quantitative changes in the values of the blood plasma redox potentials; criterion for early predicition of complications in patients with transplanted liver was proposed basing on redox potential monitoring during postoperative period.Цель исследования: определение операционных характеристик теста на основе мониторинга величин редокс-потенциала плазмы крови пациентов с различными патологическими состояниями, сопровождающимися нарушениями кислородного обмена в процессе лечения; расширение спектра параметров разработанного нами метода исследования редокс-потенциала плазмы крови.Методы: обследованы группы практически здоровых добровольцев (n =63) и пациентов со следующими патологиями: с трансплантацией почки (n =59), печени (n =64) и легкого (n =7). Измерения редокс-потенциала проводили на платиновом микроэлектроде относительно насыщенного хлорсеребряного электрода сравнения. Потенциостат IPC-Pro L (НПФ «Вольта») был использован для записи зависимостей потенциала от времени. Время регистрации составляло 15 мин.Результаты: обнаружены статистически достоверные различия в диапазонах величин редокс-потенциала для практически здоровых людей и пациентов с трансплантированными почкой и печенью. Доля измеренных величин редокс-потенциалов, совпадающих с величинами, находящимися в пределах доверительного интервала редокс-потенциалов практически здоровых людей, составила 12% для пациентов с трансплантированной почкой и 10% для пациентов с трансплантированной печенью. Обнаружено существенное различие в характере изменений величин редокс-потенциала плазмы крови при мониторинге подгрупп пациентов с наличием и отсутствием осложнений после трансплантации печени. Найдено, что чувствительность электрохимического метода определения величин редокс-потенциала плазмы крови составила 85,7%, специфичность — 69,8%, точность — 85,2%.Заключение: обнаружены диапазоны величин редокс-потенциала плазмы крови, характерные для различных патологических состояний; установлена связь эффекта проводимого лечения с количественными изменениями величин редокс-потенциала плазмы крови пациента; предложен критерий для раннего прогнозирования осложнений у пациентов с трансплантированной печенью на основе мониторинга редокс-потенциала в послеоперационном периоде.

    Renormalization group in the infinite-dimensional turbulence: third-order results

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    The field theoretic renormalization group is applied to the stochastic Navier-Stokes equation with the stirring force correlator of the form k^(4-d-2\epsilon) in the d-dimensional space, in connection with the problem of construction of the 1/d expansion for the fully developed fluid turbulence beyond the scope of the standard epsilon expansion. It is shown that in the large-d limit the number of the Feynman diagrams for the Green function (linear response function) decreases drastically, and the technique of their analytical calculation is developed. The main ingredients of the renormalization group approach -- the renormalization constant, beta function and the ultraviolet correction exponent omega, are calculated to order epsilon^3 (three-loop approximation). The two-point velocity-velocity correlation function, the Kolmogorov constant C_K in the spectrum of turbulent energy and the inertial-range skewness factor S are calculated in the large-d limit to third order of the epsilon expansion. Surprisingly enough, our results for C_K are in a reasonable agreement with the existing experimental estimates.Comment: 30 pages with EPS figure

    Palaeogenomic analysis of black rat (Rattus rattus) reveals multiple European introductions associated with human economic history

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    The distribution of the black rat (Rattus rattus) has been heavily influenced by its association with humans. The dispersal history of this non-native commensal rodent across Europe, however, remains poorly understood, and different introductions may have occurred during the Roman and medieval periods. Here, in order to reconstruct the population history of European black rats, we first generate a de novo genome assembly of the black rat. We then sequence 67 ancient and three modern black rat mitogenomes, and 36 ancient and three modern nuclear genomes from archaeological sites spanning the 1st-17th centuries CE in Europe and North Africa. Analyses of our newly reported sequences, together with published mitochondrial DNA sequences, confirm that black rats were introduced into the Mediterranean and Europe from Southwest Asia. Genomic analyses of the ancient rats reveal a population turnover in temperate Europe between the 6th and 10th centuries CE, coincident with an archaeologically attested decline in the black rat population. The near disappearance and re-emergence of black rats in Europe may have been the result of the breakdown of the Roman Empire, the First Plague Pandemic, and/or post-Roman climatic cooling.Peer reviewe

    Genomic and proteomic identification of Late Holocene remains: Setting baselines for Black Sea odontocetes

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    A critical challenge of the 21st century is to understand and minimise the effects of human activities on biodiversity. Cetaceans are a prime concern in biodiversity research, as many species still suffer from human impacts despite decades of management and conservation efforts. Zooarchaeology constitutes a valuable approach for informing conservation and management decisions by providing baseline information on the past distribution and human uses of species. However, traditional morphological species identification of mixed assemblage bones can be challenging, particularly in the case of cetaceans. To address this issue, we applied and evaluated the performance of three biomolecular approaches – Sanger sequencing, shotgun sequencing and collagen peptide fingerprinting (ZooMS) – for species identification in a mixed assemblage of 800 to 1600 years old odontocete (toothed whale) samples from the site of Chersonesus in Crimea, Ukraine. We found that ZooMS allowed for identification to the taxonomic level for 28 of our 30 samples (> 90%), identifying them as either “porpoise” or “dolphin”, and approximately half of those samples could be further identified to species level with the shotgun sequencing approach. In addition, shotgun sequencing produced several complete ancient odontocete mitogenomes and auxiliary nuclear genomic data for further exploration in a population genetic context. In contrast, both morphological identification and Sanger sequencing lacked taxonomic resolution and/or resulted in misclassification of samples. We found that the combination of ZooMS and shotgun sequencing provides a powerful tool in zooarchaeology, and here allowed for a deeper understanding of past marine resource use and its implication for current management and conservation of Black Sea odontocetes

    Rise of oceanographic barriers in continuous populations of a cetacean: the genetic structure of harbour porpoises in Old World waters

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    <p>Abstract</p> <p>Background</p> <p>Understanding the role of seascape in shaping genetic and demographic population structure is highly challenging for marine pelagic species such as cetaceans for which there is generally little evidence of what could effectively restrict their dispersal. In the present work, we applied a combination of recent individual-based landscape genetic approaches to investigate the population genetic structure of a highly mobile extensive range cetacean, the harbour porpoise in the eastern North Atlantic, with regards to oceanographic characteristics that could constrain its dispersal.</p> <p>Results</p> <p>Analyses of 10 microsatellite loci for 752 individuals revealed that most of the sampled range in the eastern North Atlantic behaves as a 'continuous' population that widely extends over thousands of kilometres with significant isolation by distance (IBD). However, strong barriers to gene flow were detected in the south-eastern part of the range. These barriers coincided with profound changes in environmental characteristics and isolated, on a relatively small scale, porpoises from Iberian waters and on a larger scale porpoises from the Black Sea.</p> <p>Conclusion</p> <p>The presence of these barriers to gene flow that coincide with profound changes in oceanographic features, together with the spatial variation in IBD strength, provide for the first time strong evidence that physical processes have a major impact on the demographic and genetic structure of a cetacean. This genetic pattern further suggests habitat-related fragmentation of the porpoise range that is likely to intensify with predicted surface ocean warming.</p
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