Aquatic Birds
Mostrando 25-36 de 37 artigos, teses e dissertações.
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25. Light microscopic morphometry of the kidneys of fourteen avian species.
Kidney volume and the volume proportions of the cortex, medulla, blood vessels larger than capillaries and ureter and ureteral ducts were investigated in 61 birds from 14 species representing passeriformes, psittaciformes, podicipediformes, anseriformes, galliformes, and columbiformes. The kidneys were fixed in situ by perfusion via their arterial supply. Ki
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26. Integral Strategy for Evaluation of Fecal Indicator Performance in Bird-Influenced Saline Inland Waters
Wild birds are an important nonpoint source of fecal contamination of surface waters, but their contribution to fecal pollution is mostly difficult to estimate. Thus, to evaluate the relation between feces production and input of fecal indicator bacteria (FIB) into aquatic environments by wild waterfowl, we introduced a new holistic approach for evaluating t
American Society for Microbiology.
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27. Ornitholimnology: Effects of grazing by the Andean flamingo (Phoenicoparrus andinus)
Experimental exclusion of the Andean flamingo (Phoenicoparrus andinus) from shallow water areas of a salt lake in the Bolivian Andes caused large increases in the biomass of microorganisms inhabiting the surface sediments, especially a large diatom (Surirella wetzeli), amebas, ciliates, and nematodes. This is a conservative demonstration of the influences th
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28. Avirulent Avian Influenza Virus as a Vaccine Strain against a Potential Human Pandemic
In the influenza H5N1 virus incident in Hong Kong in 1997, viruses that are closely related to H5N1 viruses initially isolated in a severe outbreak of avian influenza in chickens were isolated from humans, signaling the possibility of an incipient pandemic. However, it was not possible to prepare a vaccine against the virus in the conventional embryonated eg
American Society for Microbiology.
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29. Characterization of H9 Subtype Influenza Viruses from the Ducks of Southern China: a Candidate for the Next Influenza Pandemic in Humans?
A current view of the emergence of pandemic influenza viruses envisages a gene flow from the aquatic avian reservoir to humans via reassortment in pigs, the hypothetical “mixing vessel.” Understanding arising from recent H5N1 influenza outbreaks in Hong Kong since 1997 and the isolation of avian H9N2 virus from humans raises alternative options for the e
American Society for Microbiology.
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30. Characterization of a Novel Influenza A Virus Hemagglutinin Subtype (H16) Obtained from Black-Headed Gulls†
In wild aquatic birds and poultry around the world, influenza A viruses carrying 15 antigenic subtypes of hemagglutinin (HA) and 9 antigenic subtypes of neuraminidase (NA) have been described. Here we describe a previously unidentified antigenic subtype of HA (H16), detected in viruses circulating in black-headed gulls in Sweden. In agreement with establishe
American Society for Microbiology.
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31. Salmonella enterica Serovars Gallinarum and Pullorum Expressing Salmonella enterica Serovar Typhimurium Type 1 Fimbriae Exhibit Increased Invasiveness for Mammalian Cells
Salmonella enterica serovars Gallinarum and Pullorum are S. enterica biotypes that exhibit host specificity for poultry and aquatic birds and are not normally capable of causing disease in mammalian hosts. During their evolution toward host restriction serovars Gallinarum and Pullorum lost their ability to mediate mannose-sensitive hemagglutination (MSHA), a
American Society for Microbiology.
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32. Characterization of H5N1 Influenza Viruses That Continue To Circulate in Geese in Southeastern China
The H5N1 influenza virus, which killed humans and poultry in 1997, was a reassortant that possibly arose in one type of domestic poultry present in the live-poultry markets of Hong Kong. Given that all the precursors of H5N1/97 are still circulating in poultry in southern China, the reassortment event that generated H5N1 could be repeated. Because A/goose/Gu
American Society for Microbiology.
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33. The evolution of early vertebrate photoreceptors
Meeting the challenge of sampling an ancient aquatic landscape by the early vertebrates was crucial to their survival and would establish a retinal bauplan to be used by all subsequent vertebrate descendents. Image-forming eyes were under tremendous selection pressure and the ability to identify suitable prey and detect potential predators was thought to be
The Royal Society.
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34. Generation of High-Yielding Influenza A Viruses in African Green Monkey Kidney (Vero) Cells by Reverse Genetics
Influenza A viruses are the cause of annual epidemics of human disease with occasional outbreaks of pandemic proportions. The zoonotic nature of the disease and the vast viral reservoirs in the aquatic birds of the world mean that influenza will not easily be eradicated and that vaccines will continue to be needed. Recent technological advances in reverse ge
American Society for Microbiology.
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35. Viability and infectivity of Cryptosporidium parvum oocysts are retained upon intestinal passage through a refractory avian host.
Six Cryptosporidium-free Peking ducks (Anas platyrhynchos) were each orally inoculated with 2.0 x 10(6) Cryptosporidium parvum oocysts infectious to neonatal BALB/c mice. Histological examination of the stomachs jejunums, ilea, ceca, cloacae, larynges, tracheae, and lungs of the ducks euthanized on day 7 postinoculation (p.i.) revealed no life-cycle stages o
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36. Characterization of the Influenza A Virus Gene Pool in Avian Species in Southern China: Was H6N1 a Derivative or a Precursor of H5N1?
In 1997, an H5N1 influenza virus outbreak occurred in chickens in Hong Kong, and the virus was transmitted directly to humans. Because there is limited information about the avian influenza virus reservoir in that region, we genetically characterized virus strains isolated in Hong Kong during the 1997 outbreak. We sequenced the gene segments of a heterogeneo
American Society for Microbiology.