474 research outputs found

    Lake and climate models linkage: a 3-D hydrodynamic contribution

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    International audienceUnder a Canadian Foundation for Climate and Atmospheric Sciences (CFCAS) project, targeted to study the feasibility to link regional climate models with lake models, one of the tasks was to consider such a coupling in large lakes. The objective is to provide detailed information on temperature and circulation distributions of the lake to take into account the spatial variability for temperature and the heat exchange through the water's surface. The major contribution of this work is focused on realistic representation of the heat fluxes and temperature distributions to and from lakes especially during the thermally stratified ice-free periods. This paper presents the detailed 3-D ELCOM model applied in Lake Erie in order to produce, at the surface layer of the lake, the spatial distribution of temperature and heat exchanges that eventually can be coupled with a regional climate model (CRCM). Preliminary results will be presented on how this lake model may improve the regional climate models, which currently do not consider such large lake circulation effects

    Experimental Infection of Swans and Geese with Highly Pathogenic Avian Influenza Virus (H5N1) of Asian Lineage

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    Susceptibility to infection, duration of illness, and concentration of asymptomatic viral shedding vary between species of swans and geese

    Curriculum Design with Systematic Analysis, Interdisciplinary Collaboration, and Research

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    As the instructional design of courses and learning activities become a normal practice of professional development for teachers and faculty members, curriculum design has risen to tag the expertise of instructional design professionals. These curriculum design projects demand a high level of collaborative efforts to look into discipline-specific accreditation standards, to analyze existing resources including course catalogues and technology infrastructure, to update emerging pedagogy and technology, and to evaluate diverse teaching team and student compositions. This presentation will share the practical knowledge gained through several curriculum design projects from the perspectives of systematic analysis, interdisciplinary collaboration, and research

    Fatal encephalitis and myocarditis in young domestic geese (Anser anser domesticus) caused by West Nile virus.

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    During 1999 and 2000, a disease outbreak of West Nile (WN) virus occurred in humans, horses, and wild and zoological birds in the northeastern USA. In our experiments, WN virus infection of young domestic geese (Anser anser domesticus) caused depression, weight loss, torticollis, opisthotonus, and death with accompanying encephalitis and myocarditis. Based on this experimental study and a field outbreak in Israel, WN virus is a disease threat to young goslings and viremia levels are potentially sufficient to infect mosquitoes and transmit WN virus to other animal species

    Susceptibility of North American Ducks and Gulls to H5N1 Highly Pathogenic Avian Influenza Viruses

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    Species-related differences in clinical response and duration and extent of viral shedding exist between North American ducks and gulls infected with H5N1 HPAI viruses

    Pannexin 1 regulates postnatal neural stem and progenitor cell proliferation

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    <p>Abstract</p> <p>Background</p> <p>Pannexin 1 forms ion and metabolite permeable hexameric channels and is abundantly expressed in the brain. After discovering pannexin 1 expression in postnatal neural stem and progenitor cells we sought to elucidate its functional role in neuronal development.</p> <p>Results</p> <p>We detected pannexin 1 in neural stem and progenitor cells <it>in vitro</it> and <it>in vivo</it>. We manipulated pannexin 1 expression and activity in Neuro2a neuroblastoma cells and primary postnatal neurosphere cultures to demonstrate that pannexin 1 regulates neural stem and progenitor cell proliferation likely through the release of adenosine triphosphate (ATP).</p> <p>Conclusions</p> <p>Permeable to ATP, a potent autocrine/paracine signaling metabolite, pannexin 1 channels are ideally suited to influence the behavior of neural stem and progenitor cells. Here we demonstrate they play a robust role in the regulation of neural stem and progenitor cell proliferation. Endogenous postnatal neural stem and progenitor cells are crucial for normal brain health, and their numbers decline with age. Furthermore, these special cells are highly responsive to neurological injury and disease, and are gaining attention as putative targets for brain repair. Therefore, understanding the fundamental role of pannexin 1 channels in neural stem and progenitor cells is of critical importance for brain health and disease.</p

    Susceptibility of swine to H5 and H7 low pathogenic avian influenza viruses

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    Citation: Balzli, C., Lager, K., Vincent, A., Gauger, P., Brockmeier, S., Miller, L., . . . Swayne, D. E. (2016). Susceptibility of swine to H5 and H7 low pathogenic avian influenza viruses. Influenza and other Respiratory Viruses. doi:10.1111/irv.12386Background: The ability of pigs to become infected with low pathogenic avian influenza (LPAI) viruses and then generate mammalian adaptable influenza A viruses is difficult to determine. Yet, it is an important link to understanding any relationship between LPAI virus ecology and possible epidemics among swine and/or humans. Objectives: Assess susceptibility of pigs to LPAI viruses found within the United States and their direct contact transmission potential. Methods: Pigs were inoculated with one of ten H5 or H7 LPAI viruses selected from seven different bird species to test infectivity, virulence, pathogenesis, and potential to transmit virus to contact pigs through histological, RRT-PCR and seroconversion data. Results: Although pigs were susceptible to infection with each of the LPAI viruses, no clinical disease was recognized in any pig. During the acute phase of the infection, minor pulmonary lesions were found in some pigs and one or more pigs in each group were RRT-PCR-positive in the lower respiratory tract, but no virus was detected in upper respiratory tract (negative nasal swabs). Except for one group, one or more pigs in each LPAI group developed antibody. No LPAI viruses transmitted to contact pigs. Conclusions: LPAI strains from various bird populations within the United States are capable of infecting pigs. Although adaptability and transmission of individual strains seem unlikely, the subclinical nature of the infections demonstrates the need to improve sampling and testing methods to more accurately measure incidence of LPAI virus infection in pigs, and their potential role in human-zoonotic LPAI virus dynamics. © 2016 John Wiley & Sons Ltd

    Phylogenetics and Pathogenesis of Early Avian Influenza Viruses (H5N1), Nigeria

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    Three highly pathogenic avian influenza subtype H5N1 and 4 Newcastle disease viruses were isolated from sick or dead chickens in southwestern Nigeria. Sequencing and phylogenetic analysis placed them within H5N1 subclade 2.2.2. Intravenous and intranasal pathogenicity tests produced systemic disease with vascular endothelial cell tropism in chickens

    Intercontinental spread of Asian-origin H7 avian influenza viruses by captive bird trade in 1990's

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    Wild bird migration and illegal trade of infected poultry, eggs, and poultry products have been associated with the spread of avian influenza viruses (AIV). During 1992–1996, H7N1 and H7N8 low pathogenic AIV (LPAIV) were identified from captive wild birds; such as Pekin robin (Leiothrix lutea), magpie robin (Copsychus saularis), flycatcher sp. (genus Empidonax), a species of softbill and parakeet, sun conure (Aratinga solstitialis), painted conure (Pyrrhura picta), fairy bluebird (Irena puella), and common iora (Aegithina tiphia), kept in aviaries or quarantine stations in England, The Netherlands, Singapore and the United States (U.S.). In this study, we sequenced these H7 viruses isolated from quarantine facilities and aviaries using next-generation sequencing and conducted a comparative phylogenetic analysis of complete genome sequences to elucidate spread patterns. The complete genome sequencing and phylogenetic analysis suggested that H7 viruses originated from a common source, even though they were obtained from birds in distant geographical regions. All H7N1 and H7N8 viruses were LPAIV, except a H7N1 highly pathogenic AIV (HPAIV), A/Pekin robin/California/30412/1994(H7N1) virus. Our results support the continued need for regulation of the captive wild bird trade to reduce the risk of introduction and dissemination of both LPAIV and HPAIV throughout the world
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