548 research outputs found

    Metodologias de laboratório para compactação de solos para análise de desenvolvimento de plantas.

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    Equipamentos utilizados; Solos; Ensaios.bitstream/CPPSE/17483/1/Documentos-74.pdfISSN 1980-684

    Diffuse radio sources in the cluster of galaxies Abell 548b

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    We report extensive VLA and ATCA observations of the two diffuse radio sources in the cluster of galaxies Abell 548b, which confirm their classification as relics. The two relics (named A and B) show similar flux density, extent, shape, polarization and spectral index and are located at projected distances of about 430 and 500 kpc from the cluster center, on the same side of the cluster's X-ray peak. On the basis of spectral indices of discrete radio sources embedded within the diffuse features, we have attempted to distinguish emission peaks of the diffuse sources from unrelated sources. We have found that both relics, in particular the B-relic, show possible fine structure, when observed at high resolution. Another diffuse source (named C) is detected close in projection to the cluster center. High-resolution images show that it contains two discrete radio sources and a diffuse component, which might be a candidate for a small relic source. The nature and properties of the diffuse radio sources are discussed. We conclude that they are likely related to the merger activity in the cluster.Comment: Accepted for publication in MNRAS. 11 pages, 7 figures. Some figures are degraded to reduce their size. A version with high resolution images is available at http://www.ira.inaf.it/~lferetti/OUTGOING/papA548b.ps.g

    Validação de 3 Equipamentos de TDR (Reflectometria no Domínio do Tempo) para a Medida da Umidade de Solos.

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    bitstream/CNPDIA/10455/1/CT61_2004.pd

    Antigenic expression in human choroid plexus carcinoma : report of two cases

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    Neoplasias provenientes do epitélio de revestimento do plexo coróide são inco-muns, tendo sido descritos 6 padrões morfológicos. O padrão anaplásico, também denominado carcinoma do plexo coróide, é o de menor freqüência e pode dar metastases fora do SNC. A distinção histológica desses tumores, particularmente da variedade anaplásica, com outras neoplasias primárias e metastáticas no SNC pode ser difícil. O uso de técnicas imunocitoquimicas em parafina tem-se mostrado útil no esclarecimento das linhagens tumorais. Os papilomas do plexo coróide têm, no entanto, sido objeto de controvérsia, por sua complexa expressão antigênica. Usando a técnica de imunoperoxidase (sistema avidina-biotina-peroxidase) pesquisaram-se, em dois casos da variedade anaplásica, os seguintes marcadores: proteína glial fibrilar ácida (GFAP) com anticorpo monoclonal e policlonal; ceratinas de 40-50kDa, ceratinas de 60-70kDa (callus ceratina), enolase neuronal específica (NSE) e proteína S-100, com anticorpos monoclonais. Os dois tumores mostraram positividade para NSE, proteína S-100 e ceratina de 40-50kDa; uma das duas neoplasias mostrou diferenciação glial, revelando positividade para GFAP tanto com anticorpo monoclonal quanto policlonal.Primary neoplasms of choroid plexus are rare. Six morphological variants have been described: papillary, cystic, acinar, mucus-secreting, oncocytic, and anaplastic. The anaplastic variant, the so-called choroid plexus carcinoma, is the rarest of all and can metastasize. The differential diagnosis of the anaplastic variant of choroid plexus neoplasms with adenocarcinomas, melanomas and indifferentiated neoplasms can be troublesome chiefly in adults. The now large use of immunocytochemical techniques in tissue section has become a powerful tool in the analysis of cell lineages, tumoral and non-tumoral. Nevertheless, the choroid plexus neoplasms have shown a complex and a somewhat confusing pattern of antigenic expression. In two choroid plexus carcinomas (one localized in the right lateral ventricle from a boy of 1 year and 9 months old, and the other localized in the left lateral ventricle from a girl of 3 years old) the following antigens were searched (using the avidin-biotin-peroxydase complex): glial fibrillary acidic protein (GFAP) with monoclonal and polyclonal antibodies; cytokeratins of 40-50kDa, cytokeratins of 60-70kDA (callus cytokeratin), neuronal specific enolase (NSE) and S-100 protein with monoclonal antibodies. The two neoplasms showed immunoreactivity against NSE, S-100 protein and cytokeratin of 40-50kDA The neoplasm of the boy exhibited glial differentiation having immunoreactivity against GFAP with monoclonal and polyclonal antibodies

    Mathematical modelling of polyamine metabolism in bloodstream-form trypanosoma brucei: An application to drug target identification

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    © 2013 Gu et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedThis article has been made available through the Brunel Open Access Publishing Fund.We present the first computational kinetic model of polyamine metabolism in bloodstream-form Trypanosoma brucei, the causative agent of human African trypanosomiasis. We systematically extracted the polyamine pathway from the complete metabolic network while still maintaining the predictive capability of the pathway. The kinetic model is constructed on the basis of information gleaned from the experimental biology literature and defined as a set of ordinary differential equations. We applied Michaelis-Menten kinetics featuring regulatory factors to describe enzymatic activities that are well defined. Uncharacterised enzyme kinetics were approximated and justified with available physiological properties of the system. Optimisation-based dynamic simulations were performed to train the model with experimental data and inconsistent predictions prompted an iterative procedure of model refinement. Good agreement between simulation results and measured data reported in various experimental conditions shows that the model has good applicability in spite of there being gaps in the required data. With this kinetic model, the relative importance of the individual pathway enzymes was assessed. We observed that, at low-to-moderate levels of inhibition, enzymes catalysing reactions of de novo AdoMet (MAT) and ornithine production (OrnPt) have more efficient inhibitory effect on total trypanothione content in comparison to other enzymes in the pathway. In our model, prozyme and TSHSyn (the production catalyst of total trypanothione) were also found to exhibit potent control on total trypanothione content but only when they were strongly inhibited. Different chemotherapeutic strategies against T. brucei were investigated using this model and interruption of polyamine synthesis via joint inhibition of MAT or OrnPt together with other polyamine enzymes was identified as an optimal therapeutic strategy.The work was carried out under a PhD programme partly funded by Prof. Ray Welland, School of Computing Science, University of Glasgo

    Avaliação de genótipos de leguminosas forrageiras para utilização na renovação de talhões de cana-de-açúcar com solo compactado.

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    Comparar, à campo, o desempenho de linhagens selecionadas de guandu (Cajanus cajan), em comparação à cultivares de girassol (Helianthus annuus) e crotalária (Crotalaria juncea), em talhões de cana com problema de compactação de solo

    Utililização de resíduos de construção e de demolição reciclados (RCD-R) como corretivos da acidez do solo

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    Os resíduos de construção civil e demolição (RCD) são graves problemas ambientais, pois representam mais de 50% do resíduo sólido gerado nos médios e grandes centros urbanos. Por outro lado, a acidez do solo é um dos principais fatores capazes de reduzir o potencial produtivo dos solos brasileiros, pois provoca a diminuição da disponibilidade de nutrientes para as plantas. Este estudo teve o objetivo de avaliar a viabilidade da utilização do RCD-R classe A, como corretivo de acidez do solo, tendo como indicador a produção de matéria seca da alfafa (Medicago sativa cv. Crioula). Os resultados obtidos sugerem que o RCD-R cinza (origem de concreto) tem potencial para ser utilizado como corretivo da acidez de solos
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