65,893 research outputs found
Parabolic dunes in north-eastern Brazil
In this work we present measurements of vegetation cover over parabolic dunes
with different degree of activation along the north-eastern Brazilian coast. We
are able to extend the local values of the vegetation cover density to the
whole dune by correlating measurements with the gray-scale levels of a high
resolution satellite image of the dune field. The empirical vegetation
distribution is finally used to validate the results of a recent continuous
model of dune motion coupling sand erosion and vegetation growth.Comment: 18 pages, 14 figures, aubmitted to Geomorpholog
Índice de sustentabilidade do uso da água de cisternas no semi-árido brasileiro.
A disponibilidade hídrica no Semi-Árido brasileiro é baixa, embora, nos anos secos possam ocorrer, no mínimo, 300,Omm, que são suficientes para abastecer uma cisterna com capacidade de 16.000 litros e atender as necessidades básicas de uma família com cinco pessoas. Nesta região, a quantidade e a qualidade da água são indicadores que devem ser considerados na gestão sustentável da água, principalmente para consumo das famílias. Assim, este estudo avaliou os resultados obtidos pelo P1 MC/Ministério do Desenvolvimento Social - MDS, objetivando propor um índice de sustentabilidade do uso da água de cisterna. Foram utilizados procedimentos de análise fatorial em componentes principais e de agrupamento, integrando-se diferentes bases dados. A partir das variáveis analisadas foram definidos quatro indicadores de sustentabilidade da água das cisternas: a) uso da água de outras fontes; b) condições ecológicas dos domicílios; c) capacitação comunitária e d) qualidade da água. Os indicadores poderão auxiliar no monitoramento e gestão da água, no que concerne ao fornecimento da água necessária e sua qualidade, visando à melhoria da qualidade de vida dos usuários das cisternas. Os indicadores propostos poderão auxiliar na decisão dos gestores do P1 MC no sentido de revisar e reformular suas ações estratégias
Quantitative Proteomic Analysis Reveals Changes in the Benchmark Corynebacterium pseudotuberculosis Biovar Equi Exoproteome after Passage in a Murine Host
Corynebacterium pseudotuberculosis biovar equi is the etiologic agent of ulcerative lymphangitis. To investigate proteins that could be related to the virulence of this pathogen, we combined an experimental passage process using a murine model and high-throughput proteomics with a mass spectrometry, data-independent acquisition (LC-MSE) approach to identify and quantify the proteins released into the supernatants of strain 258_equi. To our knowledge, this approach allowed characterization of the exoproteome of a C. pseudotuberculosis equi strain for the first time. Interestingly, the recovery of this strain from infected mouse spleens induced a change in its virulence potential, and it became more virulent in a second infection challenge. Proteomic screening performed from culture supernatant of the control and recovered conditions revealed 104 proteins that were differentially expressed between the two conditions. In this context, proteomic analysis of the recovered condition detected the induction of proteins involved in bacterial pathogenesis, mainly related to iron uptake. In addition, KEGG enrichment analysis showed that ABC transporters, bacterial secretion systems and protein export pathways were significantly altered in the recovered condition. These findings show that secretion and secreted proteins are key elements in the virulence and adaptation of C. pseudotuberculosis. Collectively, bacterial pathogenesis-related proteins were identified that contribute to the processes of adherence, intracellular growth and evasion of the immune system. Moreover, this study enhances our understanding of the factors that may influence the pathogenesis of C. pseudotuberculosis.Fil: Marques Da Silva, Wanderson. Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas; Brasil. Institut National de la Recherche Agronomique; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Carvalho, Rodrigo D. De Oliveira. Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas; BrasilFil: Dorella, Fernanda A.. Universidade Federal de Minas Gerais; BrasilFil: Folador, Edson L.. Universidade Federal da Paraíba. Centro de Biotecnologia; BrasilFil: Souza, Gustavo H. M. F.. Waters Corporation; BrasilFil: Pimenta, Adriano M. C.. Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas; BrasilFil: Figueiredo, Henrique C. P.. Universidade Federal de Minas Gerais; BrasilFil: Le Loir, Yves. Institut National de la Recherche Agronomique; FranciaFil: Silva, Artur. Universidade Federal do Pará; BrasilFil: Azevedo, Vasco. Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas; Brasi
A dynamic method for charging-up calculations: the case of GEM
The simulation of Micro Pattern Gaseous Detectors (MPGDs) signal response is
an important and powerful tool for the design and optimization of such
detectors. However, several attempts to simulate exactly the effective charge
gain have not been completely successful. Namely, the gain stability over time
has not been fully understood. Charging-up of the insulator surfaces have been
pointed as one of the responsible for the difference between experimental and
Monte Carlo results. This work describes two iterative methods to simulate the
charging-up in one MPGD device, the Gas Electron Multiplier (GEM). The first
method uses a constant step for avalanches time evolution, very detailed, but
slower to compute. The second method uses a dynamic step that improves the
computing time. Good agreement between both methods was reached. Despite of
comparison with experimental results shows that charging-up plays an important
role in detectors operation, should not be the only responsible for the
difference between simulated and measured effective gain, but explains the time
evolution in the effective gain.Comment: Minor changes in grammatical statements and inclusion of some
important information about experimental setup at section "Comparison with
experimental results
Pressure effect in the X-ray intrinsic position resolution in noble gases and mixtures
A study of the gas pressure effect in the position resolution of an
interacting X- or gamma-ray photon in a gas medium is performed. The intrinsic
position resolution for pure noble gases (Argon and Xenon) and their mixtures
with CO2 and CH4 were calculated for several gas pressures (1-10bar) and for
photon energies between 5.4 and 60.0 keV, being possible to establish a linear
match between the intrinsic position resolution and the inverse of the gas
pressure in that energy range. In order to evaluate the quality of the method
here described, a comparison between the available experimental data and the
calculated one in this work, is done and discussed. In the majority of the
cases, a strong agreement is observed
Obtenção de peptídeos trípticos de soro do leite e avaliação da capacidade emulsionante dos hidrolisados.
Avaliação de extratos de Epicoccum sp. para o biocontrole de Magnaporthe oryzae.
O presente estudo visou o levantamento do perfil químico dos extratos de Epicoccum sp. e sua capacidade de inibir a germinação de conídios e a formação de apressórios de M. oryzae
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