884 research outputs found

    Dinâmica da população e controle biológico da cigarrinha em pastagens de Brachiaria decumbens em Rondônia.

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    Instalado na area experimental da EMBRAPA-UEPAE Porto Velho, visando controlar o ataque das cigarrinhas-das-pastagens em Rondonia. Foi iniciado em jan./1977, com seis piquetes de 1ha cada um, com pastagens de brachiaria decumens. Tres piquetes foram adubados com fosforo, 100kg/ha, e tres nao adubados. Cada piquete comportou tres garrotes de dois anos de idade.As ninfas foram contadas atraves de um quadro de madeira medindo 0,25m de lado, jogado 10 vezes ao acaso por piquete. O processo de contagem dos adultos foi feito atravesde uma rede entomologica de 0,4m de diametro. Conclui-se que: apos seis meses de aplicacao ainda encontrou-se cigarrinhas mortas; o fungo atinte jovens e adultos; apos aplicacao do fungo houve rapida recuperacao das pastagem, embora tenha ocorrido a presenca de animais. A formulacao do molhavel mostrou-se mais eficiente; recomenda-se duas aplicacoes: l - inicio das chuvas, 2 - epoca do aparecimento da primeira geracao; O efeito do Metharrhizium anisopliae de um ano para outro ainda nao forneceu dados suficientes; o novo isolado recebel a sigla K19 - 1976.bitstream/item/46844/1/COT-7-19790001.pd

    Genetic diversity of Lusitano horse in Brazil using pedigree information

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    This study aimed to evaluate population parameters and to describe the genetic diversity of the Lusitano breed in Brazil using pedigree data. Two populations were evaluated: total population (TP) containing 18,922 animals, and reference population (RP) composed of a part of TP containing 8,329 animals, representing the last generation. The generation interval (10.1 ± 5.1 years) was in the range for horse populations. Pedigree completeness in RP shows almost 100% filling in the three most recent generations, indicating improvement in the pedigree data and accuracy of the results, and the inbreeding coefficient (4.46%) and average relatedness (5.97%) for RP, indicating control on the part of breeders. The effective population size was 89 (TP) and 90 (RP). The effective number of founders (fe) were 33 and 29, effective number of ancestors (fa) were 30 and 26, and effective number of founder genomes (fg) were 19 and 15 for TP and RP, respectively, indicating a reduction of genetic variability in the last generations. The total number of ancestors that explains 100% of the genetic diversity in the Lusitano breed in Brazil was 427 (TP) and 341 (RP). The reproductive parameters, probabilities of gene origin showing loss of variability in the last generations, and the genetic contributions of ancestors suggest the need to monitor genetic diversity over time in breeding programs to allow control of the next generations and to increase their variability.info:eu-repo/semantics/publishedVersio

    IMPACT OF NANOFLUIDS ON EXTERNAL AND INTERNAL FLOW VIA NAVIER-STOKES AND CONVECTIONDIFFUSION EQUATIONS FOR PARALLEL PLATES WITH SLIP BOUNDARY CONDITIONS

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    With the modernization and miniaturization of equipment and systems toincrease the overall efficiency in smaller spaces, new cooling solutions needto be developed. Microfluidic in the last decades becomes a new way to getthis. Nanofluids are used to attend this demand to optimize efficiency, withtheir improved thermohydraulic properties, especially different thermalconductivities. To determine the advantages of using a nanofluid for thermalexchange, the properties, parameters and modelling will be presented, and thedifferential equations necessary to obtain the results. In that sense, the basictheory of fluid mechanics and heat transfer, through the Navier-Stokes andConvection-Diffusion equation, is used in the two-dimensional steady-stateformulation. Slip boundary conditions for the velocity field. Constant heat fluxand constant temperature at the surface are used for the temperature field,initially without the flow’s microscale effects. The external flow over a flatplate and internal flow between parallel plates will be studied. Considering alaminar flow, with the base fluid being water and engine oil, with variousvolumetric fractions of Single Wall and Multiple Wall Carbon Nanotubes. Todetermine the results and create the comparative graphs, the WolframMathematica v.11 software will be used for solving the remaining partialdifferential equations

    Erodibilidade do solo nos tabuleiros costeiros.

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    Para determinar perdas de solo por erosão hídrica, em diferentes situações, são utilizados modelos de predição de erosão, como a Equação Universal de Perdas de Solo (EUPS). A aplicação destes modelos, no planejamento agrícola e ambiental, depende da determinação dos fatores da EUPS, dentre estes a erodibilidade (fator K). Este estudo teve como objetivo determinar a erodibilidade, para as principais classes de solos da região dos Tabuleiros Costeiros, em Aracruz (ES). O experimento foi instalado nos seguintes solos: Argissolo Amarelo textura média/argilosa (PA1), Plintossolo Háplico (FX) e Argissolo Amarelo moderadamente rochoso (PA2). Para o cálculo da erodibilidade, foram utilizados dados de erosividade e de perdas de solo de novembro de 1997 a maio de 2004. As coletas de perdas de solo foram realizadas para cada evento de chuva considerada erosiva. Os valores de erodibilidade foram 0,007 Mg h MJ-1 mm-1; 0,017 Mg h MJ-1 mm-1; e 0,0004 Mg h MJ-1 mm-1, para PA1, FX e PA2, respectivamente

    Efeitos da micorriza e do suprimento de fósforo na atividade enzimática e na resposta de espécies arbóreas ao nitrogênio.

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    Avaliou-se, em um experimento realizado em vasos com 5 kg de um latossolo, a influencia de micorriza arbuscular e do suprimento de fosforo na micorriza arbuscular e do suprimento de fosforo na resposta da acacia (Acacia mangium (L.), fedegoso (Senna macranthera (Collad.) I & B.), cassia verrugosa (Senna multijuga (L.C.Rich) I.&B.) e angico vermelho (Anadenanthera peregrina (L.) Speg.) a adubacao nitrogenada. Verificou-se que plantas colonizadas por Glomus etunicatum (Becker & Gerdemann), mesmo apresentando menores teores de fosforo na parte aerea, apresentaram maiores respostas em crescimento a adicao de N-mineral ao solo do que quando estas foram adubadas com 360 mg de P kg-1. Para absorcao de N, verificou-se que as plantas micorrizadas apresentaram teores deN ate 2,6 vezes maior devido a aplicacao deste nutriente, enquanto nas plantas com P esta relacao nao ultrapassou 1,5. Isto indica que o efeito da micorriza na resposta da nutricao fosfatica da planta e sim devido a melhor absrocao do N via fungo micorrizico. O conteudo de proteina soluvel na folha e a atividade da GS, Fd-GOGAT e PEPC foram pouco influenciados pelos tratamentos, sendo os valores maximos observados para o fedegoso. Alem de efeitos diretos da nutricao fosfatica, a micorriza se mostrou importante para a nutricao das especies arboreas utilizadas neste estudo

    Immune cells and oxidative stress in the endotoxin tolerance mouse model

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    Sepsis is a systemic inflammatory response that can lead to tissue damage and death. In order to increase our understanding of sepsis, experimental models are needed that produce relevant immune and inflammatory responses during a septic event. We describe a lipopolysaccharide tolerance mouse model to characterize the cellular and molecular alterations of immune cells during sepsis. The model presents a typical lipopolysaccharide tolerance pattern in which tolerance is related to decreased production and secretion of cytokines after a subsequent exposure to a lethal dose of lipopolysaccharide. The initial lipopolysaccharide exposure also altered the expression patterns of cytokines and was followed by an 8- and a 1.5-fold increase in the T helper 1 and 2 cell subpopulations. Behavioral data indicate a decrease in spontaneous activity and an increase in body temperature following exposure to lipopolysaccharide. In contrast, tolerant animals maintained production of reactive oxygen species and nitric oxide when terminally challenged by cecal ligation and puncture (CLP). Survival study after CLP showed protection in tolerant compared to naive animals. Spleen mass increased in tolerant animals followed by increases of B lymphocytes and subpopulation Th1 cells. An increase in the number of stem cells was found in spleen and bone marrow. We also showed that administration of spleen or bone marrow cells from tolerant to naive animals transfers the acquired resistance status. In conclusion, lipopolysaccharide tolerance is a natural reprogramming of the immune system that increases the number of immune cells, particularly T helper 1 cells, and does not reduce oxidative stress.FAPESPCNP
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