7,232 research outputs found

    Hyperendemicity, heterogeneity and spatial overlap of leprosy and cutaneous leishmaniasis in the southern Amazon region of Brazil

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    Neglected tropical diseases characterized by skin lesions are highly endemic in the state of Mato Grosso, Brazil. We analyzed the spatial distribution of leprosy and Cutaneous Leishmaniasis (CL) and identified the degree of overlap in their distribution. All new cases of leprosy and CL reported between 2008 and 2017 through the national reporting system were included in the study. Scan statistics together with univariate Global and Local Moran's I were employed to identify clusters and spatial autocorrelation for each disease, with the spatial correlation between leprosy and CL measured by bivariate Global and Local Moran's I. Finally, we evaluated the demographic characteristics of the patients. The number of leprosy (N = 28,204) and CL (N = 24,771) cases in Mato Grosso and the highly smoothed detection coefficients indicated hyperendemicity and spatial distribution heterogeneity. Scan statistics demonstrated overlap of high-risk clusters for leprosy (RR = 2.0; p <0.001) and CL (RR = 4.0; p <0.001) in the North and Northeast mesoregions. Global Moran's I revealed a spatial autocorrelation for leprosy (0.228; p = 0.001) and CL (0.311; p = 0.001) and a correlation between them (0.164; p = 0.001). Both diseases were found to be concentrated in urban areas among men aged 31-60 years, of brown-skinned ethnicity and with a low educational level. Our findings indicate a need for developing integrated and spatially as well as socio-demographically targeted public health policies

    Charge and spin distributions in GaMnAs/GaAs Ferromagnetic Multilayers

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    A self-consistent electronic structure calculation based on the Luttinger-Kohn model is performed on GaMnAs/GaAs multilayers. The Diluted Magnetic Semiconductor layers are assumed to be metallic and ferromagnetic. The high Mn concentration (considered as 5% in our calculation) makes it possible to assume the density of magnetic moments as a continuous distribution, when treating the magnetic interaction between holes and the localized moment on the Mn(++) sites. Our calculation shows the distribution of heavy holes and light holes in the structure. A strong spin-polarization is observed, and the charge is concentrated mostly on the GaMnAs layers, due to heavy and light holes with their total angular momentum aligned anti-parallel to the average magnetization. The charge and spin distributions are analyzed in terms of their dependence on the number of multilayers, the widths of the GaMnAs and GaAs layers, and the width of lateral GaAs layers at the borders of the structure.Comment: 12 pages,7 figure

    Caracterização de plantas transgênicas de soja obtidas com a forma constitutiva do fator de transcrição AREB1.

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    O melhoramento genético da soja busca, atualmente, o desenvolvimento de cultivares mais adaptadas a condições ambientais adversas, como períodos de seca, cada vez mais severos e frequentes no cenário de mudanças climáticas. A forma constitutivamente ativa AtAREB1&#916;QT consiste em uma forma mutante do fator de transcrição bZIP AREB1, que está envolvido na via ABA dependente de resposta à seca nas plantas. Estudos feitos em Arabidopsis mostraram que a forma mutante de AREB1 aumentou a tolerância à seca nestas plantas. Dentro deste contexto, o objetivo do presente trabalho foi inserir a construção gênica pBI35S&#937;:AtAREB1&#916;QT (35S:AtAREB1&#916;QT) em soja pelo método de biobalística e caracterizar molecularmente os eventos quanto ao número de cópias e nível da expressão relativa do transgene. Foi também avaliado a segregação dos eventos na geração T1. A caracterização molecular quanto ao número de cópias inseridas no genoma vegetal foi realizada pelo uso das metodologias de Southern blot e PCR quantitativo (qPCR). Para análise do nível da expressão relativa também se utilizou do método de RT-qPCR. Os resultados confirmaram a integração do transgene no genoma da soja em 12 linhagens independentes, no entanto, o número de cópias inseridas foi diferente para cada linhagem GM obtida, considerando-se ambas as técnicas empregadas. O transgene foi transferido para a primeira geração, porém a segregação nos eventos T1 não acompanhou as leis Mendelianas. A geração e caracterização molecular dos eventos obtidos auxiliaram na escolha de eventos promissores que serão futuramente avaliados quanto o efeito do transgene na cultura da soja sob condições de deficiência hídrica

    Theory of neutral and charged exciton scattering with electrons in semiconductor quantum wells

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    Electron scattering on both neutral (XX) and charged (XX^-) excitons in quantum wells is studied theoretically. A microscopic model is presented, taking into account both elastic and dissociating scattering. The model is based on calculating the exciton-electron direct and exchange interaction matrix elements, from which we derive the exciton scattering rates. We find that for an electron density of 109cm210^9 {\rm cm}^{-2} in a GaAs QW at T=5KT=5K, the XX^- linewidth due to electron scattering is roughly twice as large as that of the neutral exciton. This reflects both the XX^- larger interaction matrix elements compared with those of XX, and their different dependence on the transferred momentum. Calculated reflection spectra can then be obtained by considering the three electronic excitations of the system, namely, the heavy-hole and light-hole 1S neutral excitons, and the heavy-hole 1S charged exciton, with the appropriate oscillator strengths.Comment: 18 pages, 12 figure

    Curva de dissipação de imazapyr em água de drenos de irrigação, após a aplicação para controle da taboa.

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    O herbicida sistémico imazapyr foi usado no controle da taboa (Typha subulata Crespo & Peres-Moreau f.) em drenos de irrigação, como alternativa ao controle mecânico. O resíduo do princípio ativo do herbicida na água foi analisado por cromatografia líquida de alta performance (HPLC). A curv a de di ss ip ação de imazapyr mostrou que o herbicida pode ser usado para o contro le de taboa em drenos de irr iga ção, sem causar danos a culturas vizinhas, desde que a água seja usada, no mínimo, depois de 1,6 a 3,7 dias da aplicação das doses de 500 a 1500 g ha-1, respectivamente
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