35 research outputs found

    Soroprevalência da infecção pelo vírus da hepatite E em suínos domésticos no Distrito Federal, Brasil

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    A hepatite E é causada pelo vírus da hepatite E (HEV), considerado um patógeno de transmissão zoonótica que tem suínos como reservatórios. No Brasil, não há informações a respeito da circulação do HEV no rebanho suíno do Distrito Federal. Por isso, foi conduzido um estudo transversal com amostras de soro de 449 suínos domésticos provenientes de 234 propriedades, cedidas pela Secretaria de Agricultura do Distrito Federal. As amostras sanguíneas foram coletadas entre junho e setembro de 2014. Um kit de ELISA comercialmente disponível foi utilizado para a detecção sorológica de anticorpos IgG contra o HEV. Foi encontrada uma alta soroprevalência de anticorpos contra o HEV, uma vez que 304 animais apresentaram amostras reagentes (67,7%, IC 95% = 63,2%, 71,9%). A soropositividade não variou com relação ao gênero ou à idade. Os resultados sugerem que o HEV circula entre os suínos domésticos no Distrito Federal, e isso pode servir como um alerta para o sistema de saúde pública da região devido ao possível envolvimento desses animais em infecções humanas.Hepatitis E is caused by the hepatitis E virus (HEV) which is currently known to be a zoonotic pathogen transmitted by pigs. In Brazil, there is no information about the circulation of HEV in the swine herd of the Federal District. Therefore, a cross-sectional study was performed with sera from 449 domestic pigs, provided by the Secretary of Agriculture of the Federal District. Blood samples were collected between June and September 2014. A commercially available ELISA kit was used for the detection of IgG antibodies. High seroprevalence of antibodies to HEV was found, since 304 animals showed anti-HEV positive reactions (67.7%; 95% CI = 63.2%, 71.9%). The seropositivity presented no difference by gender or age. The results suggest that HEV circulates among domestic pigs in the Federal District and it can serve as a warning to the local public health system due to their possible involvement in human infections

    Geography and ecology shape the phylogenetic composition of Amazonian tree communities

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    Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2^{2} = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2^{2} = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

    Geography and ecology shape the phylogenetic composition of Amazonian tree communities

    Get PDF
    AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

    Mapping density, diversity and species-richness of the Amazon tree flora

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    Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

    Geography and ecology shape the phylogenetic composition of Amazonian tree communities

    Get PDF
    Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega‐phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white‐sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long‐standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

    Mapping density, diversity and species-richness of the Amazon tree flora

    Get PDF
    Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

    One sixth of Amazonian tree diversity is dependent on river floodplains

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    Amazonia’s floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region’s floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon’s tree diversity and its function

    Soroprevalência da hepatite E em suínos no Distrito Federal, Brasil

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    A hepatite E é causada pelo vírus da hepatite E (HEV), considerado um patógeno de transmissão zoonótica e que possui suínos como reservatórios. No Brasil, não há informações a respeito da circulação do HEV no rebanho suíno do Distrito Federal. Por isso, foi conduzido um estudo transversal com amostras de soro de 449 suínos domésticos, cedidas pela Secretaria de Agricultura do Distrito Federal. As amostras sanguíneas foram coletadas entre junho e setembro de 2014. Um kit de ELISA comercialmente disponível foi utilizado para a detecção sorológica de anticorpos IgG contra o HEV. Foi encontrada uma alta soroprevalência de anticorpos contra o HEV, uma vez que 304 animais apresentaram amostras reagentes (67,7%, IC 95% = 63,2%, 71,9%). A soropositividade não variou com relação ao gênero ou à idade. Os resultados sugerem que o HEV circula entre os suínos domésticos no Distrito Federal, e isso pode servir como um alerta para o sistema de saúde pública da região devido ao possível envolvimento desses animais em infecções humanas. _____________________________________________________________________________ ABSTRACTHepatitis E is caused by hepatitis E virus (HEV) which is currently known to be a zoonotic pathogen and it has pigs as reservoirs. In Brazil, there is no information about the circulation of HEV in swine flocks of the Federal District. Therefore, a cross-sectional study was performed with sera from 449 domestic pigs, provided by the Secretary of Agriculture of the Federal District. Blood samples were collected between June and September 2014. An ELISA kit commercially available was used for the detection of IgG antibodies. It was found a high seroprevalence of antibodies to HEV, since 304 animals showed anti-HEV positive reactions (67.7%; 95% CI = 63.2%, 71.9%). The seropositivity presented no difference by gender or age. The results suggest that HEV circulates among domestic pigs in the Federal District, and it can serve as a warning to the local public health system about their possible involvement in human infections

    One sixth of Amazonian tree diversity is dependent on river floodplains

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    Amazonia’s floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region’s floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon’s tree diversity and its function
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