One sixth of Amazonian tree diversity is dependent on river floodplains

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.Naturali

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

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

Pathogen-Specific Epitopes as Epidemiological Tools for Defining the Magnitude of Mycobacterium leprae Transmission in Areas Endemic for Leprosy

Immunogenetics and cellular immunology of bacterial infectious disease

A reestruturação do trabalho docente: precarização e flexibilização Restructuring the teaching profession: precarization and flexibilization

O artigo pretende discutir as atuais condições de trabalho dos docentes de escolas públicas brasileiras, tendo como referência resultados de pesquisas empíricas e revisão bibliográfica que demonstram um contexto de reestruturação do trabalho pedagógico. Parte-se da premissa de que com a reestruturação produtiva assistida de forma mais ostensiva nas duas últimas décadas, novas demandas têm sido apresentadas à educação escolar com relação aos seus objetivos, refletindo em mudanças nas formas de gestão e organização do trabalho na escola. Tais mudanças trazidas pelas reformas educacionais mais recentes têm resultado em intensificação do trabalho docente, ampliação do seu raio de ação e, conseqüentemente, em maiores desgastes e insatisfação por parte desses trabalhadores. O texto pretende, ainda, discutir como tais mudanças interferem no que se entende como processo de flexibilização e precarização do trabalho docente à luz das teses da desprofissionalização e proletarização.<br>Based on results from empirical research and on a bibliographic review that demonstrates a context of restructuration of the pedagogical work, this paper discusses the present work conditions of teachers in the Brazilian public school system. It assumes that the very clear productive restructuration that has been occurring these last two decades brought has questioned the objectives of school education and entailed changes in the forms of work management and organization at school. Brought by the recent educational reforms, such changes have caused the intensification of teachers' work, enlarging their scope of action and consequently increasing their weariness and dissatisfaction level. The text also discusses how such changes interfere in the so-called called process of flexibilization, with an increasing precariousness of teachers' work, in the light of the theses of disprofissionalization and proletarianization

Induction of the acrosome reaction test to in vitro estimate embryo production in Nelore cattle

The effectiveness of induction of the acrosome reaction (AR) test as a parameter to in vitro estimate embryo production (IVP) in Nelore breed and the AR pattern by the Trypan Blue/Giemsa (TB) stain were evaluated. Frozen semen samples from ten Nelore bulls were submitted to AR induction and were also evaluated for cleavage and blastocyst rates. The treatments utilized for AR induction were: control (TALP medium), TH (TALP medium + 10μg heparin), TL (TALP medium + 100μg lysophosphatidylcholine) and THL (TALP medium + 10μg heparin + 100μg lysophosphatidylcholine). Sperm acrosomal status and viability were evaluated by TB staining at 0 and after 4h incubation at 38°C. The results obtained for AR presented a significant difference (P<0.05) in the percentage of acrosome reacted live sperm after 4h of incubation in the treatments that received heparin. The cleavage and blastocyst rates were 60% and 38% respectively and a significant difference was observed among bulls (P<0.05). It was founded a satisfactory model to estimate the cleavage and blastocyst rates by AR induction test. Therefore, it can be concluded that the induction of the AR test is a valuable tool to predict the IVP in Nelore breed

One sixth of Amazonian tree diversity is dependent on river floodplains

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