925 resultados para Parasite Fauna


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The hypothesis tested was that rapid rejection of Trichinella spiralis infective larvae from immunized rats following a challenge infection is associated with a local anaphylactic reaction, and this response should be reflected in altered small intestinal motility. The objective was to determine if altered gut smooth muscle function accompanies worm rejection based on the assumption that anaphylaxis in vivo could be detected by changes in intestinal smooth muscle contractile activity (ie. an equivalent of the Schultz-Dale reaction or in vitro anaphylaxis). The aims were to (1) characterize motility changes by monitoring intestinal myoelectric activity in conscious rats during the enteric phase of T. spiralis infection in immunized hosts, (2) detect the onset and magnitude of myoelectric changes caused by challenge infection in immunized rats, (3) determine the parasite stimulus causing changes, and (4) determine the specificity of host response to stimulation. Electrical slow wave frequency, spiking activity, normal interdigestive migrating myoelectric complexes and abnormal migrating action potential complexes were measured. Changes in myoelectric parameters induced by larvae inoculated into the duodenum of immune hosts differed from those associated with primary infection with respect to time of onset, magnitude and duration. Myoelectric changes elicited by live larvae could not be reproduced by inoculation of hosts with dead larvae, larval excretory-secretory products, or by challenge with a heterologous parasite, Eimeria nieschulzi. These results indicate that (1) local anaphylaxis is a component of the initial response to T. spiralis in immune hosts, since the rapid onset of altered smooth muscle function parallels in time the expression of rapid rejection of infective larvae, and (2) an active mucosal penetration attempt by the worm is necessary to elicit this host response. These findings provide evidence that worm rejection is a consequence of, or sequel to, an immediate hypersensitivity reaction elicited when parasites attempt to invade the gut mucosa of immunized hosts. ^

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In der Nordsee wurden auf der Forschungsplattform FINO 1 Felduntersuchungen durchgeführt, um spezielle Fragen zu möglichen Auswirkungen von Offshore-Windenergieparks auf die marine Umwelt zu beantworten. Der Fokus war dabei auf die Konsequenzen für die Lebensgemeinschaft am Meeresboden gerichtet. Es wurden die benthosökologischen Prozesse im Nahbereich der Piles sowie die mittelfristige Entwicklung der Aufwuchsfauna auf der künstlichen Unterwasserstruktur dokumentiert. Die Ansammlung pelagischer Fischen um die Plattform und der Export organischen Materials von der Plattform wurden quantifiziert. Die räumliche Ausdehnung und die Erheblichkeit von Auswirkungen auf die Lebensgemeinschaften des Meeresbodens wurden anhand mathematischer Modellierung abgeschätzt. Zusätzlich wurde die Anwendbarkeit der elektrochemischen Akretionstechnologie zur Schaffung naturnaher Kalksubstrate in der Nordsee getestet und geeignete Parameter für eine erfolgreiche Umsetzung unter Nordseebedingungen ermittelt. Die auch 4,5 Jahre nach Errichtung der Plattform noch ansteigende Artenzahl der Aufwuchsfauna lässt darauf schließen, dass der Sukzessionsprozess noch nicht abgeschlossen ist. Die stark vertikal zonierte Aufwuchsfauna auf der Unterwasserkonstruktion erreicht eine Masse von ca. 5 Tonnen mit ausgeprägten saisonalen Schwankungen. Anhand von echoakustischen Untersuchungen wurden saisonal auftretende Ansammlungen pelagischer Fische um die Plattform dokumentiert. Der Nahbereich der Plattform unterschied sich durch eine Schillauflage und eine räumlich und zeitlich sehr variable Sediment- und Bodenfaunazusammensetzung deutlich von einem Referenzgebiet in 200-400 m Abstand von der Plattform. Eine konzentrische Zonierung mit unterschiedlich stark ausgeprägten Veränderungen der Bodenfauna lässt auf komplexe Veränderung des gesamten lokalen Nahrungsgefüges im Nahbereich der Plattform schließen. Anhand einer Modellierung konnte der Materialexport in die umgebenden Weichbodenbereiche für einzelne Piles und einen hypothetischen Windpark abgeschätzt werden. Die lokale Ausbildung einer hohen Biomasse auf der Unterwasserkonstruktion von WEA sowie der Export mit anschließender Sedimentation lassen zumindest lokal einen erheblichen Einfluss auf Stoff- und Energieflüsse erwarten.

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Hoy día los Pirineos se han convertido en una reserva ambiental. El importante proceso de despoblación experimentado durante el siglo XX y la apropiación progresiva de gran parte de su territorio por el Estado para implementar políticas de conservación han favorecido la reaparición, a través de la reintroducción, el fomento o la recuperación espontánea, de diversas especies de grandes depredadores, aves rapaces ungulados y otros mamíferos. La gestión contemporánea de la fauna salvaje en los Pirineos, mediante la cual la naturaleza es reinventada para ajustarla a los estándares posmodernos sobre la vida silvestre, manifiesta la existencia de racionalidades y valoraciones que escapan a los criterios pretendidamente objetivos de una ecología mecánica.

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Structure of assemblages associated with mussel aggregations of Bathymodiolus azoricus was investigated. Mussel beds were found on hydrothermal vent fields on the Mid-Atlantic Ridge (Menez Gwen, Lucky Strike, and Rainbow) at depths 850-2400 m. The community structure of the mussel bed assemblages varied between studied areas. Large number of species was unique to mussel beds of the Menez Gwen field; the most observed taxa were not specialized hydrothermal species. All other nonunique species were found within the Lucky Strike region. The lowest mussel assemblage structure evenness was observed in the shallowest Menez Gwen area (850 m depth). We assume that two types of mussel assemblages (nematode-dominated and copepod-dominated) exist within the Lucky Strike field. The assemblages of B. azoricus differ significantly from assemblages of B. thermophilus inhabiting Pacific hydrothermal vents.

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Two shelf communities from the central part off the California Peninsula are described. The community of Amphiodia urtica - Nephtys ferruginea develops in the central part of the shelf within the depth range 95-105 m. The community of Nephtys ferruginea - Amphiura acrystata develops on the shelf edge at depth 110 m. Biomasses of both communities are very low (about 10 g/m**2). Species richness of the shelf community is high; more than 60 species occur in samples (43-51 species per a community). Various echinoderms and some other groups are abundant on the Californian shelf; these groups are absent in shelf areas of Peruvian and Benguela upwellings. Species structures of the communities were analyzed; the communities were shown to consist of coexisting, but not interacting guilds; this indicates that the communities are undersaturated with individuals. At the same time values of ABC-indices indicate that the communities are stable. We suggest that in this case adaptation to unfavorable but stable environment is observed (selection of species-stressolarents). An explanation seems to lie in the penetrating type of the upwelling in the Californian upwelling zone. Low biomass values seem to result from mass development of necto-benthic carnivorous crustaceans-galateids Pleuroncodes planiceps.

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No Brasil, existem aproximadamente 200 línguas indígenas, dessas algumas nao foram descritas. Grosso modo, há dois troncos linguísticos (Tupi e Macro Jê) e existem famílias linguísticas ou línguas que nao apresentam semelhanças suficientes para serem agrupadas nos troncos linguísticos conhecidos. O objetivo deste trabalho é apresentar um estudo descritivo e contrastivo em relaçao aos sememas que descrevem os animais da fauna brasileira das línguas Zoró e Parintintin baseado nos conceitos onomasiologicos. Com relaçao ao aporte teórico adotado, apoiamo-nos em Babini (2001), Barbosa (2002), Lisboa (2008) e Kurovski (2009). A metodologia consiste em pesquisa bibliográfica e comparaçao entre sememas das duas línguas com a língua portuguesa. Podemos mencionar que há elevado grau de diferenciaçao entre o português e as duas línguas estudadas. Como exemplo, pode-se mencionar que para o falante do português os sememas para "peixe pintado" seriam: "peixe e água doce", "peixe de carne saborosa", "peixe de couro" enquanto que o semema da língua zoró para o mesmo peixe seria "causa a hepatite". No caso do parintintin os sememas foram avaliados a partir do sistema exogâmico, que divide todos os seres e objetos em duas categorias: Myty e Kwandu (pássaros da Amazônia brasileira), tal classificaçao é levada em consideraçao na escolha do alimento que será consumido. Dessa forma, verificou-se que os sememas indígenas para animais representam, primordialmente, fonte de alimento e sobrevivência, e, também, estao correlacionados às questoes cosmogônicas e culturais. Por sua vez, os sememas de animais para o homem lusófono focam os aspectos visual e preservacionista. Por fim, cabe salientar que o estudo é preliminar e os dados levantados serao empregados para a construçao de um glossário onomasiológico da fauna brasileira

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Historically, the Holocene has been considered an interval of relatively stable climate. However, recent studies from the northern Arabian Sea (Netherlands Indian Ocean Program 905) suggested high-amplitude climate shifts in the early and middle Holocene based on faunal and benthic isotopic proxy records. We examined benthic foraminiferal faunal and stable isotopic data from Ocean Drilling Program (ODP) Site 723 and total organic carbon data from ODP Site 724, Oman Margin (808 and 593 m water depths, respectively). At Site 723 the mid-Holocene shift in d18O values of infaunal benthic species Uvigerina peregrina (1.4 per mil) is 3 times larger than that of epifaunal benthic species Cibicides kullenbergi recorded at Site NIOP 905 off Somalia. However, none of the five other benthic species we measured at Hole 723A exhibits such a shift in d18O. We speculate that the late Holocene d18O decrease in U. peregrina represents species-specific changes in ecological habitat or food preference in response to changes in surface and deep ocean circulation. While the stable isotopic data do not appear to indicate a middle Holocene climatic shift, our total organic carbon and benthic faunal assemblage data do indicate that the early Holocene deep Arabian Sea was influenced by increased ventilation perhaps by North Atlantic Deep Water and/or Circumpolar Deep Water incursions into the Indian Ocean, leading to remineralization of organic matter and a relatively weak early Holocene oxygen minimum zone in the northwest Arabian Sea in spite of strong summer monsoon circulation.

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46 hydropolyp species of 28 genera and 10 families were sampled during the "Meteor" passage 1964/65 (IIOE) through the Red Sea and its northern and southern exits and on the occasion of several ecological investigations of 29 selected coral reef sections of the central Red Sea and the Gulf of Aqaba. These collections comprise 128 single records of hydropolyp species. Three species and two genera each with one species are doubtful. 25 species, seven genera, one family and one subfamily, together from 49 records have not previously been found in the Red Sea and its exits. Including these newly reported species, the total list increases from 64 species and 112 records to 89 species and 240 single records and 51 additional ones. Scanning microscopical photos, made for the first time for the illustration of the hydropolyps, have been shown to be suitable for a better characterization and diagnosis of the species. Qualified results on the reasons for the horizontal distribution of the species known from the Red Sea area cannot be given because of the low number of samples sporadically distributed through the whole area. In contrast with this fact, the vertical spread of the species sampled seems primarily to be regulated by water exchange and light intensity. For example, four species of hydropolyps are excellent indicators of certain abiotic factors or combinations of them: Gymnangium eximium reacts extremely stenophote-photophobe-rheophil, Eudendrium ramosum moderately stenophote-photophobe-rheophobe, Lytocarpus philippinus moderately stenophote-photophil-rheophil, and Halocordyle disticha var. australis extremely stenophote-photophil but moderately rheophil. Other species have been found throughout all the light zones. Combined with the small size of their colonies their euryphotic behaviour does not allow their use as indicator species.

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No Brasil, existem aproximadamente 200 línguas indígenas, dessas algumas nao foram descritas. Grosso modo, há dois troncos linguísticos (Tupi e Macro Jê) e existem famílias linguísticas ou línguas que nao apresentam semelhanças suficientes para serem agrupadas nos troncos linguísticos conhecidos. O objetivo deste trabalho é apresentar um estudo descritivo e contrastivo em relaçao aos sememas que descrevem os animais da fauna brasileira das línguas Zoró e Parintintin baseado nos conceitos onomasiologicos. Com relaçao ao aporte teórico adotado, apoiamo-nos em Babini (2001), Barbosa (2002), Lisboa (2008) e Kurovski (2009). A metodologia consiste em pesquisa bibliográfica e comparaçao entre sememas das duas línguas com a língua portuguesa. Podemos mencionar que há elevado grau de diferenciaçao entre o português e as duas línguas estudadas. Como exemplo, pode-se mencionar que para o falante do português os sememas para "peixe pintado" seriam: "peixe e água doce", "peixe de carne saborosa", "peixe de couro" enquanto que o semema da língua zoró para o mesmo peixe seria "causa a hepatite". No caso do parintintin os sememas foram avaliados a partir do sistema exogâmico, que divide todos os seres e objetos em duas categorias: Myty e Kwandu (pássaros da Amazônia brasileira), tal classificaçao é levada em consideraçao na escolha do alimento que será consumido. Dessa forma, verificou-se que os sememas indígenas para animais representam, primordialmente, fonte de alimento e sobrevivência, e, também, estao correlacionados às questoes cosmogônicas e culturais. Por sua vez, os sememas de animais para o homem lusófono focam os aspectos visual e preservacionista. Por fim, cabe salientar que o estudo é preliminar e os dados levantados serao empregados para a construçao de um glossário onomasiológico da fauna brasileira