68 research outputs found

    Detection and Evaluation of metals in soil under influence of mining by Dispersive Energy X-ray Fluorescence Spectrometry (EDXRF), Lavras do Sul/RS

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    Rocks are the primary source of chemical elements found in the earth. Among them metallic elements, which are distributed in most natural environments and their distribution in soils is widespread. Knowledge of the soil chemical composition will provide subsidies for a prediction of phytotoxicity and possible groundwater contamination. Concentrations of metals, in the right quantities, are essential for maintaining life. Although, if in high quantities (toxicity), can cause damage to plants, animals, and humans. This work consists of a chemical analysis of soil samples in the region of Lavras do Sul / RS, where mineral deposits occur. Until the year 1981 mining activities occupied the area without municipality, resulting in ore and waste deposits at inappropriate places, generating environmental liabilities, contributing to soil chemistry, and consequently affecting public health. Through the energy dispersive X-ray fluorescence spectrometry (EDXRF) method, 20 soil samples were analyzed in two profiles surrounding the municipality. Among them, high concentrations of Zn, Cu, Ce and Cd were detected, possibly contributing to anthropic activities and seasonal fluctuations

    Coordination and Selectivity of Protection Devices with Reliability Assessment in Distribution Systems

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    This chapter provides an overview of the reliability of electricity distribution networks, and its evaluation that is linked with the protection system. In this way, the characteristics of network protection are presented, along with the peculiarities in coordination and device selectivity adjustments. For the assessment of the reliability, we have the methodology of logic-structural matrix (LSM) that integrates the constitution of the network with historical data of faults, so that with this, a model can be elaborated that can evaluate the impact of changes in the system directly on the reliability indicators

    Cell-associated hemolysis activity in the clinical strain of Pseudomonas fluorescens MFN1032

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    <p>Abstract</p> <p>Background</p> <p>MFN1032 is a clinical <it>Pseudomonas fluorescens </it>strain able to grow at 37°C. MFN1032 cells induce necrosis and apoptosis in rat glial cells at this temperature. This strain displays secretion-mediated hemolytic activity involving phospholipase C and cyclolipopeptides. Under laboratory conditions, this activity is not expressed at 37°C. This activity is tightly regulated and is subject to phase variation.</p> <p>Results</p> <p>We found that MFN1032 displays a cell-associated hemolytic activity distinct from the secreted hemolytic activity. Cell-associated hemolysis was expressed at 37°C and was only detected <it>in vitro </it>in mid log growth phase in the presence of erythrocytes. We studied the regulation of this activity in the wild-type strain and in a mutant defective in the Gac two-component pathway. GacS/GacA is a negative regulator of this activity. In contrast to the <it>Pseudomonas fluorescens </it>strains PfO-1 and Pf5, whose genomes have been sequenced, the MFN1032 strain has the type III secretion-like genes <it>hrc</it>RST belonging to the <it>hrpU </it>operon. We showed that disruption of this operon abolished cell-associated hemolytic activity. This activity was not detected in <it>P.fluorescens </it>strains carrying similar <it>hrc </it>genes, as for the <it>P. fluorescens </it>psychrotrophic strain MF37.</p> <p>Conclusions</p> <p>To our knowledge this the first demonstration of cell-associated hemolytic activity of a clinical strain of <it>Pseudomonas fluorescens</it>. Moreover, this activity seems to be related to a functional <it>hrpU </it>operon and is independent of biosurfactant production. Precise link between a functional <it>hrpU </it>operon and cell-associated hemolytic activity remains to be elucidated.</p

    Signatures of Galaxy-Cluster Interactions: Spiral Galaxy Rotation Curve Asymmetry, Shape, and Extent

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    The environmental dependencies of the characteristics of spiral galaxy rotation curves are studied in this work. We use our large, homogeneously collected sample of 510 cluster spiral galaxy rotation curves to test the claim that the shape of a galaxy's rotation curve strongly depends on its location within the cluster, and thus presumably on the strength of the local intracluster medium and on the frequency and strength of tidal interactions with the cluster and cluster galaxies. Our data do not corroborate such a scenario, consistent with the fact that Tully-Fisher residuals are independent of galaxy location within the cluster; while the average late-type spiral galaxy shows more rise in the outer parts of its rotation curve than does the typical early-type spiral galaxy, there is no apparent trend for either subset with cluster environment. We also investigate as a function of cluster environment rotation curve asymmetry and the radial distribution of H II region tracers within galactic disks. Mild trends with projected cluster-centric distance are observed: (i) the (normalized) radial extent of optical line emission averaged over all spiral galaxy types shows a 4%+/-2% increase per Mpc of galaxy-cluster core separation, and (ii) rotation curve asymmetry falls by a factor of two between the inner and outer cluster for early-type spirals (a negligible decrease is found for late-type spirals). Such trends are consistent with spiral disk perturbations or even the stripping of the diffuse, outermost gaseous regions within the disks as galaxies pass through the dense cluster cores.Comment: 17 pages; to appear in the April 2001 Astronomical Journa

    Espiritualidade e Busca pelo Desenvolvimento Humano nas Organizações

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    RESUMO: O tema espiritualidade ganha espaço no ambiente organizacional como forma de compreensão mais plena do ser humano. Para as organizações, o desenvolvimento humano é um diferencial para o crescimento econômico por meio do entendimento da individualidade de cada profissional. O objetivo deste estudo foi analisar a importância da espiritualidade como valor estimulado para o desenvolvimento humano dentro das organizações. Realizou-se uma pesquisa com abordagem qualitativa por meio da técnica de coleta de dados de entrevistas em profundidade, com roteiro semiestruturado com gestores e especialistas do tema localizados na região serrana do estado do Rio Grande do Sul. Os dados foram analisados por meio da técnica de análise de conteúdo e os resultados apontaram divergências das práticas e entendimentos sobre a espiritualidade nas organizações. Mesmo assim, houve concordância sobre a importância do tema, ligada às práticas de âmbito cultural da empresa mais do que como um aspecto humanístico estruturado a ser trabalhado. Foram propostos direcionamentos no sentido de potencializar o desenvolvimento humano por meio da espiritualidade nas organizações. Palavras-Chave: Espiritualidade. Desenvolvimento humano. Aprendizado organizacional. &nbsp; ABSTRACT: The topic of spirituality has gained prominence in the organizational environment as a way of better understanding human being. For organizations, human development is a differential for economic growth through the understanding of the individuality of each professional. The purpose of this study was to analyze the importance of spirituality as a stimulated value for human development within organizations. A research with a qualitative approach was carried out through the technique of data collection of in-depth interviews, with semi-structured script with managers and specialists of the subject located in the mountainous region of the state of Rio Grande do Sul. Data were analyzed through the technique of content analysis and the results pointed out differences of practices and understandings about spirituality in organizations. Even so, there was agreement on the importance of the theme, linked to the cultural practices of the company rather than as a structured humanistic aspect to be worked on. Directions have been proposed to enhance human development through spirituality in the organizations. Keywords: Spirituality. Human development. Organizational learning

    A review of abnormalities in the perception of visual illusions in schizophrenia

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    Specific abnormalities of vision in schizophrenia have been observed to affect high-level and some low-level integration mechanisms, suggesting that people with schizophrenia may experience anomalies across different stages in the visual system affecting either early or late processing or both. Here, we review the research into visual illusion perception in schizophrenia and the issues which previous research has faced. One general finding that emerged from the literature is that those with schizophrenia are mostly immune to the effects of high-level illusory displays, but this effect is not consistent across all low-level illusions. The present review suggests that this resistance is due to the weakening of top–down perceptual mechanisms and may be relevant to the understanding of symptoms of visual distortion rather than hallucinations as previously thought

    The Cpx envelope stress response both facilitates and inhibits elaboration of the enteropathogenic Escherichia coli bundle-forming pilus

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    The Cpx envelope stress response is induced by the misfolding of periplasmic proteins and restores envelope homeostasis by upregulating several periplasmic protein folding and degrading factors. The Cpx response also regulates the expression of a variety of envelope-spanning protein complexes, including flagella, secretion systems and pili, which play an important role in pathogenesis. In a previous study, we inactivated the Cpx response in enteropathogenic Escherichia coli (EPEC), a causative agent of infant diarrhoea, and observed decreased expression of its major adhesin, the bundle-forming pilus (BFP). Here, we examined the mechanism underlying this BFP expression defect, and found that this phenotype can be attributed to insufficient expression of periplasmic folding factors, such as DsbA, DegP and CpxP. Hence, a low level of Cpx pathway activity promotes BFP synthesis by upregulating factors important for folding of BFP component proteins. Conversely, we found that full induction of the Cpx response inhibits BFP expression, mainly by repressing transcription of the bfp gene cluster. In combination with a previous report examining EPEC type III secretion, our results demonstrate that the Cpx response co-ordinates the repression of cell-surface structures during periods of envelope stress

    Capillary Regeneration in Scleroderma: Stem Cell Therapy Reverses Phenotype?

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    BACKGROUND. Scleroderma is an autoimmune disease with a characteristic vascular pathology. The vasculopathy associated with scleroderma is one of the major contributors to the clinical manifestations of the disease. METHODOLOGY/PRINCIPAL FINDINGS. We used immunohistochemical and mRNA in situ hybridization techniques to characterize this vasculopathy and showed with morphometry that scleroderma has true capillary rarefaction. We compared skin biopsies from 23 scleroderma patients and 24 normal controls and 7 scleroderma patients who had undergone high dose immunosuppressive therapy followed by autologous hematopoietic cell transplant. Along with the loss of capillaries there was a dramatic change in endothelial phenotype in the residual vessels. The molecules defining this phenotype are: vascular endothelial cadherin, a supposedly universal endothelial marker required for tube formation (lost in the scleroderma tissue), antiangiogenic interferon α (overexpressed in the scleroderma dermis) and RGS5, a signaling molecule whose expression coincides with the end of branching morphogenesis during development and tumor angiogenesis (also overexpressed in scleroderma skin. Following high dose immunosuppressive therapy, patients experienced clinical improvement and 5 of the 7 patients with scleroderma had increased capillary counts. It was also observed in the same 5 patients, that the interferon α and vascular endothelial cadherin had returned to normal as other clinical signs in the skin regressed, and in all 7 patients, RGS5 had returned to normal. CONCLUSION/SIGNIFICANCE. These data provide the first objective evidence for loss of vessels in scleroderma and show that this phenomenon is reversible. Coordinate changes in expression of three molecules already implicated in angiogenesis or anti-angiogenesis suggest that control of expression of these three molecules may be the underlying mechanism for at least the vascular component of this disease. Since rarefaction has been little studied, these data may have implications for other diseases characterized by loss of capillaries including hypertension, congestive heart failure and scar formation.Scleroderma Research Foundatio
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