1,311 research outputs found

    Analysis of the influence of drainage channels in environmental degradation in the flooded plain of Paraná river, Brazil

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    Artigo extraído de dissertação de Mestrado em Ciências Florestais do Departamento de Engenharia Florestal – UnB.Agradecimentos ao CNPq, CAPES, EMBRAPA Pantanal, CESP, Fundação Giacometti e EMBRAPA-CENARGEN.A pesquisa teve como objetivo analisar a influência dos canais de drenagem artificiais construídos para ampliar a área agrícola e de pastagem nas áreas úmidas na planície de inundação do rioParaná, utilizando um Sistema de Informação Geográfica (SIG). Foram selecionadas imagens de satélite nas épocas da seca e da chuva. A partir de transectos obtidos nos sobrevôos na área, foram coletados 50 pontos com canal e sem canal, com o auxílio de um GPS. Esses pontos foram plotados nas imagens classificadas. Em seguida foram gerados “buffers” de 1 km de raio.A partir destes “buffers” foi analisada a disponibilidade das áreas de várzea (campo alagado e úmido) nas épocas seca e chuvosa. O campo alagado na época da cheia não foi influenciadopela presença de canais de drenagem, enquanto que na seca os canais de drenagem influenciaram a disponibilidade destas áreas. O mesmo não aconteceu com o campo úmido que sofreu influência dos canais de drenagem tanto na época seca quanto na época da chuva. A redução de campo alagado na seca, em áreas com canal, foi de 56,2% e em áreas sem canal foi de 9%. ______________________________________________________________________________ ABSTRACTThe main aim of this study was to analyse the influence of the artificial drainage channelsconstructed to enlarge pasture at the plain humid areas of the Paraná river, using the GIS system.To achieve it were collected satellite images during the dry and wet seasons. Through over flytransects of the area were collected 50 spots with and without channels, with the aid of a GPS system. These spots were plotted at the satellite images that were processed generating buffers of 1 km range. From these buffers were analysed the availability of varzea area (flooded andhumid fields) during both periods. The flooded fields during the high waters season were notaffected by the presence of drainage channels, while during the dry season the drainage channelsaffected these areas. The same did not happen with the humid fields, that during both seasons suffered the influence of the drainage channels. The flooded area during the dry season reduced56.2% in the areas with drainage channels, and 9% in the areas without channel

    Fatores econômicos relacionados à intervenção na vegetação para a implantação de linhas de transmissão no estado de Rondônia.

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    The study was made on an electric energy transmission line between the cities of Ji-Paraná and Pimenta Bueno, in the State of Rondônia. The objective was to quantify the economic factors related to the suppression of vegetation by traditional and selective methods. The selective method cost was estimated according to the number of individuals per hectare, the area of intervention and the cost of felled trees. The total cost of the traditional method was determined by the area of intervention and by the cost of deforested hectares. The transposal of a fragment with the use of seven 55m towers, with no intervention in the vegetation, generates an increase of only 2,8% on the total cost, if compared to the cost of employing seven 35m towers plus the costs of a selective intervention in the vegetation. In the selective method, the number of individuals per hectare is the most important variable because it indicates directly the value to be wasted with the felling of trees. The traditional method will grow out of use because it does not offer big advantages in tecnicals envairomentals and economics terms.A pesquisa foi realizada em uma linha de transmissão de energia elétrica entre as cidades de Ji-Paraná e Pimenta Bueno, no estado de Rondônia. O objetivo foi quantificar os fatores econômicos relacionados à supressão da vegetação pelos métodos tradicional e seletivo. O custo do método seletivo foi estimado com base no número de indivíduos por hectare, da área de intervenção e do custo por árvore abatida. O custo total do método tradicional foi determinado pela área de intervenção e pelo custo do hectare desflorestado. A transposição de um fragmento com uso de sete torres de 55 m, sem-intervenção na vegetação, gera um acréscimo de apenas 2,8% no custo total, se comparado ao custo do uso de 7 torres de 35m somado aos custos de intervenção seletiva na vegetação. No método seletivo, o número de indivíduos, por hectare, é a variável mais importante, pois indica diretamente o valor a ser gasto com abate de árvores. O método tradicional deve entrar em desuso por não oferecer grandes vantagens em termos técnicos, ambientais e econômicos

    Multicenter randomized trial of cell therapy in cardiopathies – MiHeart Study

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    BACKGROUND: Cardiovascular diseases are the major cause of death in the world. Current treatments have not been able to reverse this scenario, creating the need for the development of new therapies. Cell therapies have emerged as an alternative for cardiac diseases of distinct causes in experimental animal studies and more recently in clinical trials. METHOD/DESIGN: We have designed clinical trials to test for the efficacy of autologous bone marrow derived mononuclear cell therapies in four different cardiopathies: acute and chronic ischemic heart disease, and Chagasic and dilated cardiomyopathy. All trials are multicenter, randomized, double-blind and placebo controlled. In each trial 300 patients will be enrolled and receive optimized therapy for their specific condition. Additionally, half of the patients will receive the autologous bone marrow cells while the other half will receive placebo (saline with 5% autologous serum). For each trial there are specific inclusion and exclusion criteria and the method for cell delivery is intramyocardial for the chronic ischemic heart disease and intracoronary for all others. Primary endpoint for all studies will be the difference in ejection fraction (determined by Simpson's rule) six and twelve months after intervention in relation to the basal ejection fraction. The main hypothesis of this study is that the patients who receive the autologous bone-marrow stem cell implant will have after a 6 month follow-up a mean increase of 5% in absolute left ventricular ejection fraction in comparison with the control group. DISCUSSION: Many phase I clinical trials using cell therapy for cardiac diseases have already been performed. The few randomized studies have yielded conflicting results, rendering necessary larger well controlled trials to test for efficacy of cell therapies in cardiopathies. The trials registration numbers at the NIH registry are the following: Chagasic cardiomyopathy (NCT00349271), dilated cardiomyopathy (NCT00333827), acute myocardial infarction (NCT00350766) and Chronic Ischemic Heart Disease (NCT00362388)

    Correlação de Spearman aplicada ao estudo de adaptabilidade e estabilidade em genótipos de alfafa

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    Este trabalho teve por objetivo propor uma nova metodologia, baseada no coeficiente de correlação de Spearman para o estudo da adaptabilidade e estabilidade fenotípica de genótipos de alfafa. Além disso, os resultados foram comparados com os obtidos pela metodologia baseada no teste dos sinais. Para tanto, foram utilizados dados provenientes de um experimento em blocos casualizados com 2 repetições, que constituiu-se da avaliação da produção de matéria seca de 92 cultivares de alfafa em 20 cortes, realizados no período de novembro de 2004 a junho de 2006 no Campo Experimental da Embrapa Pecuária Sudeste - São Carlos/SP. Os resultados encontrados mostram que o coeficiente de correlação de Spearman é eficiente para o estudo de adaptabilidade e estabilidade fenotípica, sendo possível classificar os cultivares conforme o interesse do estudo. Ademais, quando comparado com a metodologia baseado no teste dos sinais, o mesmo se mostra mais eficiente na discriminação de genótipos

    APBSmem: A Graphical Interface for Electrostatic Calculations at the Membrane

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    Electrostatic forces are one of the primary determinants of molecular interactions. They help guide the folding of proteins, increase the binding of one protein to another and facilitate protein-DNA and protein-ligand binding. A popular method for computing the electrostatic properties of biological systems is to numerically solve the Poisson-Boltzmann (PB) equation, and there are several easy-to-use software packages available that solve the PB equation for soluble proteins. Here we present a freely available program, called APBSmem, for carrying out these calculations in the presence of a membrane. The Adaptive Poisson-Boltzmann Solver (APBS) is used as a back-end for solving the PB equation, and a Java-based graphical user interface (GUI) coordinates a set of routines that introduce the influence of the membrane, determine its placement relative to the protein, and set the membrane potential. The software Jmol is embedded in the GUI to visualize the protein inserted in the membrane before the calculation and the electrostatic potential after completing the computation. We expect that the ease with which the GUI allows one to carry out these calculations will make this software a useful resource for experimenters and computational researchers alike. Three examples of membrane protein electrostatic calculations are carried out to illustrate how to use APBSmem and to highlight the different quantities of interest that can be calculated
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