57 resultados para Caiman crocodilus yacare
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El uso comercial de fauna silvestre genera debates éticos y pragmáticos. Los debates pragmáticos discuten si ese aprovechamiento puede favorecer o dificultar la conservación de las especies y los ambientes donde habitan. Los abordajes conceptuales tradicionales analizan el eslabonamiento productivo a partir de los flujos de capital y producto enfatizando escasamente en los actores sociales intervinientes, lo que resulta insuficiente para evaluar su trayectoria en términos de sustentabilidad. El objetivo de este trabajo es desarrollar un modelo conceptual que identifique variables sociales y económicas y su influencia en el aprovechamiento sustentable desde la perspectiva de los actores sociales involucrados en el uso comercial de fauna silvestre. Con herramientas metodológicas propias de la etnografía, los sistemas blandos y las redes sociales se analizaron el: 1) el sistema argentino de producción de yacaré, y 2) el sistema argentino helicícola. Se conceptualizaron ambos sistemas definiendo estructuras, efectos umbral, estados de equilibrio y metas. La contrastación de sistemas aparentemente diferentes permitió identificar cinco categorías clave: 1) demanda internacional de los productos, 2) las relaciones sociales entre actores participantes, 3) la estructura productiva, 4) el marco regulatorio y 5) el estado de conservación de las poblaciones silvestres. El modelo conceptual desarrollado articula las condiciones objetivas y subjetivas sobre las que interactúan los actores sociales involucrados, reconociendo el carácter co-evolutivo entre los seres humanos y la naturaleza. Esta herramienta de diagnóstico y planificación es un aporte original que permite visualizar la magnitud de la intervención en la naturalez, según los intereses sociales que subyacen y evaluar el impacto de dicha intervención sobre la conservación de las especies utilizadas.
Resumo:
El uso comercial de fauna silvestre genera debates éticos y pragmáticos. Los debates pragmáticos discuten si ese aprovechamiento puede favorecer o dificultar la conservación de las especies y los ambientes donde habitan. Los abordajes conceptuales tradicionales analizan el eslabonamiento productivo a partir de los flujos de capital y producto enfatizando escasamente en los actores sociales intervinientes, lo que resulta insuficiente para evaluar su trayectoria en términos de sustentabilidad. El objetivo de este trabajo es desarrollar un modelo conceptual que identifique variables sociales y económicas y su influencia en el aprovechamiento sustentable desde la perspectiva de los actores sociales involucrados en el uso comercial de fauna silvestre. Con herramientas metodológicas propias de la etnografía, los sistemas blandos y las redes sociales se analizaron el: 1)el sistema argentino de producción de yacaré, y 2)el sistema argentino helicícola. Se conceptualizaron ambos sistemas definiendo estructuras, efectos umbral, estados de equilibrio y metas. La contrastación de sistemas aparentemente diferentes permitió identificar cinco categorías clave: 1)demanda internacional de los productos, 2)las relaciones sociales entre actores participantes, 3)la estructura productiva, 4)el marco regulatorio y 5)el estado de conservación de las poblaciones silvestres. El modelo conceptual desarrollado articula las condiciones objetivas y subjetivas sobre las que interactúan los actores sociales involucrados, reconociendo el carácter co-evolutivo entre los seres humanos y la naturaleza. Esta herramienta de diagnóstico y planificación es un aporte original que permite visualizar la magnitud de la intervención en la naturalez, según los intereses sociales que subyacen y evaluar el impacto de dicha intervención sobre la conservación de las especies utilizadas.
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Patients want and need comprehensive and accurate information about their medicines so that they can participate in decisions about their healthcare: In particular, they require information about the likely risks and benefits that are associated with the different treatment options. However, to provide this information in a form that people can readily understand and use is a considerable challenge to healthcare professionals. One recent attempt to standardise the Language of risk has been to produce sets of verbal descriptors that correspond to specific probability ranges, such as those outlined in the European Commission (EC) Pharmaceutical Committee guidelines in 1998 for describing the incidence of adverse effects. This paper provides an overview of a number of studies involving members of the general public, patients, and hospital doctors, that evaluated the utility of the EC guideline descriptors (very common, common, uncommon, rare, very rare). In all studies it was found that people significantly over-estimated the likelihood of adverse effects occurring, given specific verbal descriptors. This in turn resulted in significantly higher ratings of their perceived risks to health and significantly lower ratings of their likelihood of taking the medicine. Such problems of interpretation are not restricted to the EC guideline descriptors. Similar levels of misinterpretation have also been demonstrated with two other recently advocated risk scales (Caiman's verbal descriptor scale and Barclay, Costigan and Davies' lottery scale). In conclusion, the challenge for risk communicators and for future research will be to produce a language of risk that is sufficiently flexible to take into account different perspectives, as well as changing circumstances and contexts of illness and its treatments. In the meantime, we urge the EC and other legislative bodies to stop recommending the use of specific verbal labels or phrases until there is a stronger evidence base to support their use.
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Low O-2 levels in the lungs of birds and mammals cause constriction of the pulmonary vasculature that elevates resistance to pulmonary blood flow and increases pulmonary blood pressure. This hypoxic pulmonary vasoconstriction (HPV) diverts pulmonary blood flow from poorly ventilated and hypoxic areas of the lung to more well-ventilated parts and is considered important for the local matching of ventilation to blood perfusion. In the present study, the effects of acute hypoxia on pulmonary and systemic blood flows and pressures were measured in four species of anesthetized reptiles with diverse lung structures and heart morphologies: varanid lizards (Varanus exanthematicus), caimans (Caiman latirostris), rattlesnakes (Crotalus durissus), and tegu lizards (Tupinambis merianae). As previously shown in turtles, hypoxia causes a reversible constriction of the pulmonary vasculature in varanids and caimans, decreasing pulmonary vascular conductance by 37 and 31%, respectively. These three species possess complex multicameral lungs, and it is likely that HPV would aid to secure ventilation-perfusion homogeneity. There was no HPV in rattlesnakes, which have structurally simple lungs where local ventilation-perfusion inhomogeneities are less likely to occur. However, tegu lizards, which also have simple unicameral lungs, did exhibit HPV, decreasing pulmonary vascular conductance by 32%, albeit at a lower threshold than varanids and caimans (6.2 kPa oxygen in inspired air vs. 8.2 and 13.9 kPa, respectively). Although these observations suggest that HPV is more pronounced in species with complex lungs and functionally divided hearts, it is also clear that other components are involved.
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Includes bibliography
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Este trabalho analisou o uso da fauna silvestre pelas populações rurais e urbanas do município de Abaetetuba, PA (S 1°42.008’ W 048°54.009’), tendo como meta a geração de conhecimentos que viabilizem as ações futuras de implementação de programas de produção comercial de animais silvestres nesta região. Para tanto foram: 1) aplicados questionários aos vendedores e aos freqüentadores da feira livre do município, assim como realizado o monitoramento do comércio de carne silvestre ao longo do ano de 2005; 2) realizadas visitas as comunidades ribeirinhas e aplicados questionários aos moradores das ilhas Capim, Xingu e Quianduba; 3) verificado o nível de conhecimento dos produtores rurais a cerca da viabilidade ou não de implementação de programas de criação de animais silvestres na região. As atividades na feira livre mostraram que em 2005 aproximadamente 5.970 kg de carne de animais silvestres pertencentes a oito etno-espécies (mucura, veado, capivara, paca, tatu, jacaré-açu, jacaré-tinga e matamatá) foram comercializadas, sendo que as carnes de capivara e jacaré foram as mais representativas, 64% e 34%, respectivamente. Os comerciantes apresentaram alta dependência financeira desta atividade, obtendo mensalmente uma renda de até R$ 600,00. Os consumidores moravam no município ou em regiões próximas e compraram os produtos mais por hábitos culturais do que necessidades financeiras. As principais atividades de subsistência (pesca e agro-extrativismo de açaí) praticadas pelas populações ribeirinhas encontram-se em declínio ou não atendem as necessidades alimentares da comunidade ao longo de todo o ano. A caça ainda se constitui uma atividade comum para os ribeirinhos entrevistados, cerca de 38% (n= 55) destes caçaram durante o último ano um total de 68 animais de pequeno porte, incluindo a mucura, a cutia, o tatu, a paca, o soia e o camaleão. Os animais maiores podem estar localmente extintos em função da sobre-caça. Os produtores rurais indicaram como fatores favoráveis para a criação de animais silvestres a proteção das populações naturais e a geração de renda; e como desfavoráveis a falta de assistência técnica e de apoio financeiro, a burocracia e os altos custos de produção. A formação de um sistema participativo de manejo, envolvendo a comunidade, o governo e o setor privado, que garanta o estabelecimento uma cadeia produtiva funcional, é apontada como uma ferramenta necessária para a implantação de sistema de criação comercial de animais silvestre neste município.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Agronomia (Ciência do Solo) - FCAV
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At present time, there is a lack of knowledge on the interannual climate-related variability of zooplankton communities of the tropical Atlantic, central Mediterranean Sea, Caspian Sea, and Aral Sea, due to the absence of appropriate databases. In the mid latitudes, the North Atlantic Oscillation (NAO) is the dominant mode of atmospheric fluctuations over eastern North America, the northern Atlantic Ocean and Europe. Therefore, one of the issues that need to be addressed through data synthesis is the evaluation of interannual patterns in species abundance and species diversity over these regions in regard to the NAO. The database has been used to investigate the ecological role of the NAO in interannual variations of mesozooplankton abundance and biomass along the zonal array of the NAO influence. Basic approach to the proposed research involved: (1) development of co-operation between experts and data holders in Ukraine, Russia, Kazakhstan, Azerbaijan, UK, and USA to rescue and compile the oceanographic data sets and release them on CD-ROM, (2) organization and compilation of a database based on FSU cruises to the above regions, (3) analysis of the basin-scale interannual variability of the zooplankton species abundance, biomass, and species diversity.
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Two features make the tooth an excellent model in the study of evolutionary innovations: the relative simplicity of its structure and the fact that the major tooth-forming genes have been identified in eutherian mammals. To understand the nature of the innovation at the molecular level, it is necessary to identify the homologs of tooth-forming genes in other vertebrates. As a first step toward this goal, homologs of the eutherian amelogenin gene have been cloned and characterized in selected species of monotremes (platypus and echidna), reptiles (caiman), and amphibians (African clawed toad). Comparisons of the homologs reveal that the amelogenin gene evolves quickly in the repeat region, in which numerous insertions and deletions have obliterated any similarity among the genes, and slowly in other regions. The gene organization, the distribution of hydrophobic and hydrophilic segments in the encoded protein, and several other features have been conserved throughout the evolution of the tetrapod amelogenin gene. Clones corresponding to one locus only were found in caiman, whereas the clawed toad possesses at least two amelogenin-encoding loci.