775 research outputs found

    Aplicação de Sensoriamento Remoto na análise das mudanças da vegetação de campos de altitude no Pantanal usando dados multitemporais Landsat. e2321497

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    Due to the cold climate and altitude, to identify trends in the dynamic vegetation and the main factors that contribute to changes in vegetation cover in grassland areas is essential to understand climate change in mountainous regions. Landsat-8 OLI and Landsat-1 MSS images from 1973 to 2022 of Morraria do Urucum and Serra do Amolar were pre-processed in the GEE cloud platform and QGIS. The resampling method per pixel in the scale of values defined for vegetation Campos de Altitude was used to show changes in vegetation cover and its dynamics through the NDVI index. In both study areas, a continuous trend of significant reduction of vegetation in highland grasslands was observed over 50 years. The average decrease was 49% for Urucum (less 2,164 hectares) and 43% for Amolar (less 3,959 hectares). The use of GHG to obtain remote sensing data combined with temporal image analysis offers the potential to quickly perceive trends in large-and small-scale vegetation cover chang

    Inquérito sorológico sôbre leptospiroses realizado no Vale do Cariri, Estado do Ceará, pela III Bandeira Científica do Centro Acadêmico Oswaldo Cruz da Faculdade de Medicina da Universidade de São Paulo

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    Agglutination-tests for leptospirosis were performed in 376 sera. The following sero-types of Leptospira were used: L. icterohemorrhagiae, L. canicola, L. grippo-typhosa, L. pomona, L. bataviae, L. australis B, L. sejroe, L. pyrogenes and L. suis. Six sera (1.59%) were positive for L. icterohemorrhagiae. From the whole group two people were born in this region, what makes possible the conclusion that the disease exists in the region.Com o propósito de estudar o problema das leptospiroses no Vale do Cariri, Ceará, foram examinados 376 soros colhidos entre moradores da região. Foram feitas provas de sôro-aglutinação usando-se os seguintes sôro-tipos de Leptospira: L. icterohemorrhagiae, L. canícola, L. grippo-typhosa, L. pomona, L. bataviae, L. australis B, L. sejroe, L. pyrogenes e L. suis. Seis soros reagiram positivamente frente à L. icterohemorrhagiae, o que dá percentual de 1,59%. Dois dos indivíduos haviam nascido e vivido no Vale, donde foi possível concluir que a leptospirose existe, autóctone, na região

    Impactos negativos da administração de hidroxicloroquina e anticoagulante em pacientes com infecção por SARS-COV-2: um ensaio clínico randomizado

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    Objetivo: Avaliar antimalárico com ou sem tratamento anticoagulante, em pacientes com infecção recente por SARS-COV-2. Métodos: Estudo clínico realizado no Hospital das Clínicas Samuel Libânio da Universidade do Vale do Sapucaí, Pouso Alegre-MG. Aprovado pelo Comitê de Ética (4.034.077) e registrado nos Ensaios Clínicos (NCT04788355). Pacientes suspeitos de COVID-19 foram incluídos na sala de emergência. Os grupos foram: C (controle) com 6 pacientes, A (anticoagulante apixabana) com 9 pacientes, H (hidroxicloroquina) com 5 pacientes e HA (hidroxicloroquina e anticoagulante apixabana) com 8 pacientes. Resultados: não houve diferenças significativas entre os grupos. O grupo HA, no qual houve intervenção com dois medicamentos, apresentou maior número de dias com sintomas (p = 0,037) e piores resultados, quando comparado ao controle: os sintomas mais relevantes foram: tosse (p = 0,001), e anosmia/ageusia (p = 0,011) cefaléia (p = 0,001). Conclusão: O presente estudo teve início quando havia dúvidas sobre o uso de medicamentos como hidroxicloroquina (HCQ) e apixabana (APX). O “n” reduzido foi definido por meio de questões burocráticas e polêmicas independentes das ações dos autores. Nenhum benefício clínico foi associado com HCQ e APX. Houve um aumento no número de dias sintomáticos quando HCQ e APX foram administrados. Apesar das limitações, não houve indicação terapêutica dos medicamentos avaliados.Purpose: To evaluate antimalarial with or without anticoagulant treatment, in patients with recent SARS-COV-2 infection. Methods: Clinical study carried out at Samuel Libânio Clinic Hospital, University of Vale do Sapucaí, Pouso Alegre-MG. Approved by the Ethics Committee (4.034.077) and registered in the Clinical Trials (NCT04788355). Suspected patients for COVID-19 were included in the emergency room. The groups were: C (control) with 6 patients, A (anticoagulant apixaban) with 9 patients, H (hydroxychloroquine) with 5 patients and HA (hydroxychloroquine and anticoagulant apixaban) with 8 patients. Results: there were no significant differences between groups. The HA group, in which there was an intervention with two drugs, presented a greater number of days with symptoms (p = 0.037) and worse results, when compared to the control: most relevant symptoms, were: cough (p = 0.001), and anosmia / ageusia (p = 0.011) headache (p = 0.001). Conclusion: The present study began when there were doubts about the use of drugs such as Hydroxychloroquine (HCQ) and apixaban (APX). The reduced “n” was defined through bureaucratic and polemic issues independent of the authors’ actions. No clinical benefit was associated with HCQ and APX. There was an increase in the number of symptomatic days when HCQ and APX were administered. Despite the limitations, there was no therapeutic indication of the evaluated drugs

    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

    Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

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    Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

    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

    Estimating the global conservation status of more than 15,000 Amazonian tree species

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    Brazilian legislation on genetic heritage harms biodiversity convention goals and threatens basic biology research and education

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