119 research outputs found
Chemically alternating langmuir-blodgett thin films as a model for molecular depth profiling by mass spectrometry
Spatial Re-Establishment Dynamics of Local Populations of Vectors of Chagas Disease
Chagas disease is transmitted by blood-sucking bugs (vectors) and presents a severe public health threat in the Americas. Worldwide there are approximately 10 million people infected with Chagas disease, a disease for which there is currently no effective cure. Vector suppression is the main strategy to control the spread of this disease. Unfortunately, the vectors have been resurgent in some areas. It is important to understand the dynamics of reinfestation where it occurs. Here we show how different models fitted to patch-level bug infestation data can elucidate different aspects of re-establishment dynamics. Our results demonstrated a 6-month time lag between detection of a new infestation and dispersal events, seasonality in dispersal rates and effects of previous vector infestation on subsequent vector establishment rates. In addition we provide estimates of dispersal distances and the effect of insecticide spraying on rates of vector re-establishment. While some of our results confirm previous findings, the effects of season and previous infestation on bug establishment challenge our current understanding of T. infestans ecology and highlight important gaps in our knowledge of T. infestans dispersal
Boraginaceae s.l. A. Juss. em uma área de Caatinga da ESEC Raso da Catarina, BA, Brasil
Tournefortia L. (Boraginaceae): espécies do Brasil extra-amazônico
Tournefortia possui cerca de 150 espécies distribuídas nas regiões quentes do mundo, principalmente nos Neotrópicos. Está sendo fornecido o tratamento necessário para identificação das espécies de Tournefortia para o Brasil, exceto região Amazônica, incluindo chaves taxonômicas e descrições. Foram encontradas as duas secções: Tournefortia e Cyphocyema, abrangendo 15 espécies e uma variedade. São apresentados comentários sobre a morfologia dos caracteres utilizados na identificação e distribuição geográfica.Tournefortia has about 150 species distributed in warm regions of the world, especially in the Neotropics. In this study all Brazilian species of Tournefortia, except those from the Amazonian region, are treated. Two sections, Tournefortia and Cyphocyema, with 15 species and one variety were found. It was previously known only to southwestern Brazil. Keys, descriptions, comments on morphological taxonomic characters and geographic distribution are also provided.Universidade Federal de Mato Grosso Instituto de Ciências NaturaisUniversidade Estadual Paulista Departamento de Zoologia e BotânicaUniversidade Estadual Paulista Instituto de Biociências Departamento de BotânicaUniversidade Estadual Paulista Departamento de Zoologia e BotânicaUniversidade Estadual Paulista Instituto de Biociências Departamento de Botânic
Sedentary behavior in Brazilian children and adolescents: a systematic review
ABSTRACT OBJECTIVE To describe the methodological characteristics of the studies selected and assess variables associated with sedentary behavior in Brazilian children and adolescents. METHODS For this systematic review, we searched four electronic databases: PubMed, Web of Knowledge, LILACS, SciELO. Also, electronic searches were applied in Google Scholar. A supplementary search was conducted in the references lists of the included articles and in non-indexed journals. We included observational studies with children and adolescents aged from three to 19 years developed in Brazil, presenting analyses of associations based on regression methods and published until September 30, 2014. RESULTS Of the 255 potential references retrieved by the searches, 49 met the inclusion criteria and composed the descriptive synthesis. In this set, we identified a great number of cross-sectional studies (n = 43; 88.0%) and high methodological variability on the types of sedentary behavior assessed, measurement tools and cut-off points used. The variables most often associated with sedentary behavior were “high levels of body weight” (in 15 out of 27 studies; 55.0%) and “lower level of physical activity” (in eight out of 16 studies; 50.0%). CONCLUSIONS The findings of this review raise the following demands to the Brazilian agenda of sedentary behavior research geared to children and adolescents: development of longitudinal studies, validation of measuring tools, establishment of risk cut-offs, measurement of sedentary behavior beyond screen time and use of objective measures in addition to questionnaires. In the articles available, the associations between sedentary behavior with “high levels of body weight” and “low levels of physical activity” were observed in different regions of Brazil
Ocorrência de dor lombar e fatores associados em crianças e adolescentes de uma escola privada do sul do Brasil
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