1,415 research outputs found

    Preliminary PCR-based screening indicates a higher incidence of Porcine Endogenous Retrovirus subtype C (PERV-C) in feral versus domestic swine

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    Xenotransplantation is considered a potential alternative to allotransplantation to relieve the current shortage of human organs. Due to their similar size and physiology, the organs of pigs are of particular interest for this purpose. Endogenous retroviruses are a result of integration of retroviral genomes into the genome of infected germ cells as DNA proviruses, which are then carried in all cells of the offspring of the organism. Porcine endogenous retroviruses (PERVs) are of special concern because they are found in pig organs and tissues that might otherwise be used for xenotransplantation. PERV proviruses can be induced to replicate and recombine in pigs, and have been shown to infect human cells in vitro. There are three subtypes of PERVs based on differences in the receptor binding domain of the env protein; PERV-A, PERV-B, and PERV-C. PERVs A and B can infect human cells in vitro and can recombine with PERV-C, resulting in a recombinant virus with a higher rate of replication in pig and human cell lines. In this study, we used a PCR-based analysis of 50 domestic and 35 feral pigs to study the distribution of PERVs A, B, and C in swine raised under domestic conditions, versus feral swine from rural areas. PERV-A and PERV-B were universal in both domestic and feral swine. Feral swine had a higher incidence of PERV-C (85.7%) compared to domestic swine (42.0%). Further studies in other feral swine herds are ongoing to verify this observation

    How the asymmetry of internal potential influences the shape of I-V characteristic of nanochannels

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    Ion transport in biological and synthetic nanochannels is characterized by such phenomena as ion current fluctuations, rectification, and pumping. Recently, it has been shown that the nanofabricated synthetic pores could be considered as analogous to biological channels with respect to their transport characteristics \cite{Apel, Siwy}. The ion current rectification is analyzed. Ion transport through cylindrical nanopores is described by the Smoluchowski equation. The model is considering the symmetric nanopore with asymmetric charge distribution. In this model, the current rectification in asymmetrically charged nanochannels shows a diode-like shape of IVI-V characteristic. It is shown that this feature may be induced by the coupling between the degree of asymmetry and the depth of internal electric potential well. The role of concentration gradient is discussed

    Use of soil moisture information in yield models

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    There are no author-identified significant results in this report

    Life Support Baseline Values and Assumptions Document

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    The Baseline Values and Assumptions Document (BVAD) provides analysts, modelers, and other life support researchers with a common set of values and assumptions which can be used as a baseline in their studies. This baseline, in turn, provides a common point of origin from which many studies in the community may depart, making research results easier to compare and providing researchers with reasonable values to assume for areas outside their experience. This document identifies many specific physical quantities that define life support systems, serving as a general reference for spacecraft life support system technology developers

    Questionable Research Practices Among Researchers in the Most Research-Productive Management Programs

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    Questionable research practices (QRPs) among researchers have been a source of concern in many fields of study. QRPs are often used to enhance the probability of achieving statistical significance which affects the likelihood of a paper being published. Using a sample of researchers from ten top research-productive management programs, we compared hypotheses tested in dissertations to those tested in journal articles derived from those dissertations to draw inferences concerning the extent of engagement in QRPs. Results indicated that QRPs related to changes in sample size and covariates were associated with unsupported dissertation hypotheses becoming supported in journal articles. Researchers also tended to exclude unsupported dissertation hypotheses from journal articles. Likewise, results suggested that many article hypotheses may have been created after the results were known (i.e., HARKed). Articles from prestigious journals contained a higher percentage of potentially HARKed hypotheses than those from less well-regarded journals. Finally, articles published in prestigious journals were associated with more QRP usage than less prestigious journals. QRPs increase in the percentage of supported hypotheses and effect sizes that likely result in overestimated population parameters. As such, results reported in articles published in our most prestigious journals may be less credible than previously believed

    Rare and Endangered Vetebrates of Ohio

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    Author Institution: U.S. Soil Conservation Service; Introductory Biology Program, The Ohio State University; School of Natural Resources, The Ohio State University; and Division of Wildlife, Ohio Department of Natural ResourcesThis paper, an annotated list of Ohio's rare and endangered vertebrate species, was compiled to supplement a similar national list and includes 10 mammals, 62 birds, 10 reptiles, 4 amphibians, and 33 fishes. Where possible, suggestions are made both as to causes of the rare or endangered status of these species and as to means of halting the trend. Ratings of endangered, rare, peripheral, or undetermined, as defined for the national classification, are given for each species

    Response to sub-threshold stimulus is enhanced by spatially heterogeneous activity

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    Sub-threshold stimuli cannot initiate excitations in active media, but surprisingly as we show in this paper, they can alter the time-evolution of spatially heterogeneous activity by modifying the recovery dynamics. This results in significant reduction of waveback velocity which may lead to spatial coherence, terminating all activity in the medium including spatiotemporal chaos. We analytically derive model-independent conditions for which such behavior can be observed.Comment: 5 pages, 5 figure

    Videoconference Fatigue Exploring Changes in Fatigue after Videoconference Meetings during COVID-19

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    In response to the COVID-19 global health pandemic, many employees transitioned to remote work, which included remote meetings. With this sudden shift, workers and the media began discussing videoconference fatigue, a potentially new phenomenon of feeling tired and exhausted attributed to a videoconference. In the present study, we examine the nature of videoconference fatigue, when this phenomenon occurs, and what videoconference characteristics are associated with fatigue using a mixed methods approach. Thematic analysis of qualitative responses indicates that videoconference fatigue exists, often in near temporal proximity to the videoconference, and is affected by various videoconference characteristics. Quantitative data was collected each hour during five workdays from 55 employees who were working remotely because of the COVID-19 pandemic. Latent growth modeling results suggest that videoconferences at different times of the day are related to deviations in employee fatigue beyond what is expected based on typical fatigue trajectories. Results from multilevel modeling of 279 videoconference meetings indicate that turning off the microphone and having higher feelings of group belongingness are related to lower post-videoconference fatigue. Additional analyses suggest that higher levels of group belongingness are the most consistent protective factor against videoconference fatigue. Such findings have immediate practical implications for workers and organizations as they continue to navigate the still relatively new terrain of remote work

    Avalanche of Bifurcations and Hysteresis in a Model of Cellular Differentiation

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    Cellular differentiation in a developping organism is studied via a discrete bistable reaction-diffusion model. A system of undifferentiated cells is allowed to receive an inductive signal emenating from its environment. Depending on the form of the nonlinear reaction kinetics, this signal can trigger a series of bifurcations in the system. Differentiation starts at the surface where the signal is received, and cells change type up to a given distance, or under other conditions, the differentiation process propagates through the whole domain. When the signal diminishes hysteresis is observed

    Vortex Dynamics in Dissipative Systems

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    We derive the exact equation of motion for a vortex in two- and three- dimensional non-relativistic systems governed by the Ginzburg-Landau equation with complex coefficients. The velocity is given in terms of local gradients of the magnitude and phase of the complex field and is exact also for arbitrarily small inter-vortex distances. The results for vortices in a superfluid or a superconductor are recovered.Comment: revtex, 5 pages, 1 encapsulated postscript figure (included), uses aps.sty, epsf.te
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