103 research outputs found

    Elastic Scattering of Neutrinos off Polarized Electrons

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    We calculate the cross sections for elastic nu_l + e -> nu_l + e and antinu_l + e -> antinu_l + e scattering (l=e, mu or tau) in the Born approximation and with exactly fixed polarization states of target and final-state electrons, discussing their sensitivity to the incident (anti)neutrino flavor. We suggest investigation of the flavor composition of a (anti)neutrino beam by a flux-independent analysis of the scattering of its constituents off polarized electrons.Comment: 6 pages, 2 figure

    Neutrino Electromagnetic Form Factors Effect on the Neutrino Cross Section in Dense Matter

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    The sensitivity of the differential cross section of the interaction between neutrino-electron with dense matter to the possibly nonzero neutrino electromagnetic properties has been investigated. Here, the relativistic mean field model inspired by effective field theory has been used to describe non strange dense matter, both with and without the neutrino trapping. We have found that the cross section becomes more sensitive to the constituent distribution of the matter, once electromagnetic properties of the neutrino are taken into account. The effects of electromagnetic properties of neutrino on the cross section become more significant for the neutrino magnetic moment mu_nu > 10^{-10} mu_B and for the neutrino charge radius R > 10^{-5} MeV^{-1}.Comment: 24 pages, 10 figures, submitted to Physical Review

    Mean-field driven first-order phase transitions in systems with long-range interactions

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    We consider a class of spin systems on Zd\Z^d with vector valued spins (\bS_x) that interact via the pair-potentials J_{x,y} \bS_x\cdot\bS_y. The interactions are generally spread-out in the sense that the Jx,yJ_{x,y}'s exhibit either exponential or power-law fall-off. Under the technical condition of reflection positivity and for sufficiently spread out interactions, we prove that the model exhibits a first-order phase transition whenever the associated mean-field theory signals such a transition. As a consequence, e.g., in dimensions d3d\ge3, we can finally provide examples of the 3-state Potts model with spread-out, exponentially decaying interactions, which undergoes a first-order phase transition as the temperature varies. Similar transitions are established in dimensions d=1,2d=1,2 for power-law decaying interactions and in high dimensions for next-nearest neighbor couplings. In addition, we also investigate the limit of infinitely spread-out interactions. Specifically, we show that once the mean-field theory is in a unique ``state,'' then in any sequence of translation-invariant Gibbs states various observables converge to their mean-field values and the states themselves converge to a product measure.Comment: 57 pages; uses a (modified) jstatphys class fil

    Syndrome of intraabdominal hypertension: pathophysiological aspects and surgical problems

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    Syndrome of intraabdominal hypertension: pathophysiological aspects and surgical problem

    Interspecific transfer of parasites following a range-shift in Ficedula flycatchers

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    Human‐induced climate change is expected to cause major biotic changes in species distributions and thereby including escalation of novel host‐parasite associations. Closely related host species that come into secondary contact are especially likely to exchange parasites and pathogens. Both the Enemy Release Hypothesis (where invading hosts escape their original parasites) and the Novel Weapon Hypothesis (where invading hosts bring new parasites that have detrimental effects on native hosts) predict that the local host will be most likely to experience a disadvantage. However, few studies evaluate the occurrence of interspecific parasite transfer by performing wide‐scale geographic sampling of pathogen lineages, both within and far from host contact zones. In this study, we investigate how haemosporidian (avian malaria) prevalence and lineage diversity vary in two, closely related species of passerine birds; the pied flycatcher Ficedula hypoleuca and the collared flycatcher F. albicollis in both allopatry and sympatry. We find that host species is generally a better predictor of parasite diversity than location, but both prevalence and diversity of parasites vary widely among populations of the same bird species. We also find a limited and unidirectional transfer of parasites from pied flycatchers to collared flycatchers in a recent contact zone. This study therefore rejects both the Enemy Release Hypothesis and the Novel Weapon Hypothesis and highlights the complexity and importance of studying host‐parasite relationships in an era of global climate change and species range shifts.</p

    Geographical trends in the yolk carotenoid composition of the pied flycatcher (Ficedula hypoleuca)

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    Carotenoids in the egg yolks of birds are considered to be important antioxidants and immune stimulants during the rapid growth of embryos. Yolk carotenoid composition is strongly affected by the carotenoid composition of the female’s diet at the time of egg formation. Spatial and temporal differences in carotenoid availability may thus be reflected in yolk concentrations. To assess whether yolk carotenoid concentrations or carotenoid profiles show any large-scale geographical trends or differences among habitats, we collected yolk samples from 16 European populations of the pied flycatcher, Ficedula hypoleuca. We found that the concentrations and proportions of lutein and some other xanthophylls in the egg yolks decreased from Central Europe northwards. The most southern population (which is also the one found at the highest altitude) also showed relatively low carotenoid levels. Concentrations of β-carotene and zeaxanthin did not show any obvious geographical gradients. Egg yolks also contained proportionally more lutein and other xanthophylls in deciduous than in mixed or coniferous habitats. We suggest that latitudinal gradients in lutein and xanthophylls reflect the lower availability of lutein-rich food items in the northern F. hypoleuca populations and in montane southern populations, which start egg-laying earlier relative to tree phenology than the Central European populations. Similarly, among-habitat variation is likely to reflect the better availability of lutein-rich food in deciduous forests. Our study is the first to indicate that the concentration and profile of yolk carotenoids may show large-scale spatial variation among populations in different parts of the species’ geographical range. Further studies are needed to test the fitness effects of this geographical variation

    Connecting the data landscape of long-term ecological studies: The SPI-Birds data hub

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    The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-term studies of birds, we have created the SPI-Birds Network and Database (www.spibirds.org)\u2014a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI-Birds has recruited over 120 members, and currently hosts data on almost 1.5 million individual birds collected in 80 populations over 2,000 cumulative years, and counting. SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by the principles of Findable, Accessible, Interoperable and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language). The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such as ours, COMADRE for animal demography, etc.) will aid much-needed large-scale ecological data integration

    ЭФФЕКТИВНОСТЬ ЗОЛЕДРОНОВОЙ КИСЛОТЫ В ПРОФИЛАКТИКЕ КОСТНЫХ МЕТАСТАЗОВ У ПАЦИЕНТОВ С МЕСТНО-РАСПРОСТРАНЕННЫМ РАКОМ ПРЕДСТАТЕЛЬНОЙ ЖЕЛЕЗЫ

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    The analysis of the performed study has established that zoledronic acid is an effective agent in multimodality therapy for locally advanced prostate cancer (PC) and allows long-term stabilization of bone tissue. In addition, there is evidence for the efficacy of zoledronic acid in preventing bone metastases (BM) and increasing the time to the first BM. The currently accumulated experience with zoledronic acid used in PC permits one to consider its use as standard concomitant therapy.На основании анализа проведенного исследования установлено, что золедроновая кислота является эффективным препаратом в комплексной терапии местно-распространенного рака предстательной железы (РПЖ) и позволяет стабилизировать в течение длительного времени состояние костной ткани. Кроме того, подтверждена эффективность золедроновой кислоты в профилактике костных метастазов (КМ), а также в увеличении времени до появления первого КМ. Накопленный к настоящему времени опыт использования золедроновой кислоты при РПЖ позволяет рассматривать ее назначение как стандартную сопроводительную терапию

    The great tit HapMap project: A continental‐scale analysis of genomic variation in a songbird

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    This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The code to reproduce the results is available on Github: https://github.com/lgs85/SpurginBosse_Hapmap. The data, including the Plink-formatted genotype files from all populations, and the downstream outputs are on Dryad: https://doi.org/10.5061/dryad.w3r2280z5.A major aim of evolutionary biology is to understand why patterns of genomic diversity vary within taxa and space. Large-scale genomic studies of widespread species are useful for studying how environment and demography shape patterns of genomic divergence. Here, we describe one of the most geographically comprehensive surveys of genomic variation in a wild vertebrate to date; the great tit (Parus major) HapMap project. We screened ca 500,000 SNP markers across 647 individuals from 29 populations, spanning ~30 degrees of latitude and 40 degrees of longitude – almost the entire geographical range of the European subspecies. Genome-wide variation was consistent with a recent colonisation across Europe from a South-East European refugium, with bottlenecks and reduced genetic diversity in island populations. Differentiation across the genome was highly heterogeneous, with clear ‘islands of differentiation’, even among populations with very low levels of genome-wide differentiation. Low local recombination rates were a strong predictor of high local genomic differentiation (FST), especially in island and peripheral mainland populations, suggesting that the interplay between genetic drift and recombination causes highly heterogeneous differentiation landscapes. We also detected genomic outlier regions that were confined to one or more peripheral great tit populations, probably as a result of recent directional selection at the species' range edges. Haplotype-based measures of selection were related to recombination rate, albeit less strongly, and highlighted population-specific sweeps that likely resulted from positive selection. Our study highlights how comprehensive screens of genomic variation in wild organisms can provide unique insights into spatio-temporal evolutionary dynamics.Natural Environment Research Council (NERC)European Research Council (ERC)Biotechnology and Biological Sciences Research Council (BBSRC
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