888 resultados para Statherian and Calymmian extension events
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Neutrophils are key effectors of the innate immune response. Reduction of neutrophil migration to infection sites is associated with a poor outcome in sepsis. We have demonstrated a failure of neutrophil migration in lethal sepsis. Together with this failure, we observed more bacteria in both peritoneal exudates and blood, followed by a reduction in survival rate. Furthermore, neutrophils obtained from severe septic patients displayed a marked reduction in chemotactic response compared with neutrophils from healthy subjects. The mechanisms of neutrophil migration failure are not completely understood. However, it is known that they involve systemic Toll-like receptor activation by bacteria and/or their products and result in excessive levels of circulating cytokines/chemokines. These mediators acting together with LPS stimulate expression of iNOS that produces high amounts of NO, which in turn mediates the failure of neutrophil migration. NO reduced expression of CXCR2 on neutrophils and the levels of adhesion molecules on both endothelial cells and neutrophils. These events culminate in decreased endothelium-leukocyte interactions, diminished neutrophil chemotactic response, and neutrophil migration failure. Additionally, the NO effect, at least in part, is mediated by peroxynitrite. In this review, we summarize what is known regarding the mechanisms of neutrophil migration impairment in severe sepsis.
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Purpose: The aim of this study was to perform qualitative and quantitative analyses of the effect of nicotine on autogenous bone block grafts and to describe events in the initial healing phase and the differences in the repair processes between animals exposed to nicotine and controls. Materials and Methods: Forty-eight female Wistar rats were randomly divided into 2 groups, the nicotine group and the saline group. All animals received either nicotine (3 mg/kg) or saline 4 weeks before the surgical procedure and continued to receive nicotine from surgery to sacrifice at 7, 14, or 28 days. The autogenous bone block graft was harvested from the calvaria and stabilized on the external cortical area near the angle of the mandible. Results: The histologic analyses of the nicotine group depicted a delay in osteogenic activity at the bed-graft interface, as well as impairment of the organization of the granulation tissue that developed instead of blood clot. Nicotine-group specimens exhibited less bone neoformation, and the newly formed bone was poorly cellularized and vascularized. The histometric analysis revealed significantly less bone formation in the nicotine group at both 14 days (23.75% +/- 6.18% versus 51.31% +/- 8.31%) and 28 days (42.44% +/- 8.70% versus 73.00% +/- 4.99%). Conclusion: Nicotine did jeopardize the early healing process of autogenous bone block grafts in rats but did not prevent it.
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Early HIV-1 reverse transcription can be separated into initiation and elongation phases. Here we show, using PCR analysis of negative-strand strong-stop DNA [(-)ssDNA] synthesis in intact virus, that different reverse transcriptase (RT) inhibitors affect distinct phases of early natural endogenous reverse transcription (NERT), The effects of nevirapine on NERT were consistent with a mechanism of action including both specific and nonspecific binding events. The nonspecific component of this inhibition targeted the elongation reaction, whereas the specific effect seemed principally to be directed at very early events (initiation or the initiation-elongation switch), In contrast, foscarnet and the nucleoside analog ddATP inhibited both early and late (-)ssDNA synthesis in a similar manner. We also examined compounds that targeted other viral proteins and found that Ro24-7429 (a Tat antagonist) and rosmarinic acid (an integrase inhibitor) also directly inhibited RT, Our results indicate that NERT can be used to identify and evaluate compounds that directly target the reverse transcription complex.
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There is substantial economic potential for exploiting wildlife resources for non-consumptive wildlife-oriented recreation (NCWOR) tourism and this type of tourism if well managed, can result in the long-term conservation of wildlife resources. This is especially important in cases where wildlife resources are declining due to habitat destruction, poaching and other human threats, as is so for sea turtles. In this paper, relevant ecotourism literature outlining the economic values of NCWOR activities is reviewed to show that a significant potential exists for developing sea turtle-based tourism. Duffus and Dearden's (1990. Biological Conservation, 53, 213-231) conceptual framework for the development of wildlife tourism and its extension and application by Higham (1998. Tourism Management, 19 (6), 521-531) is analysed to see if it might be applied to sea turtle-based ecotourism in Australia at Mon Repos Conservation Park. Threats to sea turtle populations are growing especially as a result of human activities and these underline the importance of finding an economic rationale to conserve the remaining species. Economic benefits from turtle-based tourism can provide such a rationale. However, such tourism must be managed appropriately if it is to be sustained. Queensland Parks and Wildlife Service has adopted management strategies at Mon Repos Conservation Park with this in mind and these strategies are outlined. (C) 2001 Elsevier Science Ltd. All rights reserved.
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Specific point mutations in caveolin-3, a predominantly muscle-specific member of the caveolin family, have been implicated in limb-girdle muscular dystrophy and in rippling muscle disease. We examined the effect of these mutations on caveolin-3 localization and function. Using two independent assay systems, Raf activation in fibroblasts and neurite extension in PC12 cells, we show that one of the caveolin-3 point mutants, caveolin-3-C71W, specifically inhibits signaling by activated H-Ras but not by K-Ras. To gain insights into the effect of the mutant protein on H-Ras signaling, we examined the localization of the mutant proteins in fibroblastic cells and in differentiating myotubes. Unlike the previously characterized caveolin-3-DGV mutant, the inhibitory caveolin-3-C71W mutant reached the plasma membrane and colocalized with wild type caveolins. In BHK cells, caveolin-3-C71W associated with caveolae and in differentiating muscle cells with the developing T-tubule system. In contrast, the caveolin-3-P104L mutant accumulated in the Golgi complex and had no effect on H-Ras-mediated Raf activation. Inhibition by caveolin-3-C71W was rescued by cholesterol addition, suggesting that the mutant protein perturbs cholesterol-rich raft domains. Thus, we have demonstrated that a naturally occurring caveolin-3 mutation can inhibit signaling involving cholesterol-sensitive raft domains.
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A detailed study of the Goniopora reef profile at Dengloujiao, Xuwen County, Leizhou Peninsula, the northern coast of the South China Sea suggests that a series of high-frequency, large-amplitude and abrupt cold events occurred during the Holocene Hypsithermal, an unusual phenomenon termed Leizhou Events in this paper. This period (corresponding to C-14 age of 6.2 -6.7 kaBP or calendar age of 6.7-7.2 kaBP), when the climatic conditions were ideal for coral. reefs to develop, can be divided into at least nine stages. Each stage (or called a climate optimum), lasting about 20 to 50 a, was terminated by an abrupt cold nap and (or) a sea-level lowering event in winter, leading to widespread emergence and death of the Goniopora corals, and growth discontinuities on the coral surface. Such a cyclic process resulted in the creation of a > 4m thick Goniopora reef flat. During this period, the crust subsided periodically but the sea level was rising. The reef profile provides valuable archives for the study of decadal-scale mid-Holocene climatic oscillations in the tropical area of South China. Our results provide new evidence for high-frequency climate instability in the Holocene Hypsithermal, and challenge the traditional understanding of Holocene climate.
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RESUMO: Com a globalização e as mudanças provenientes da mesma, o ser humano vem sofrendo com o estresse ao tentar se adaptar e acompanhar tais acontecimentos seja no âmbito familiar, social, afetivo e profissional. Para desempenhar as funções docentes do ensino superior, são exigidas diversas condições, e o professor sofre um desgaste físico e psicológico ao tentar suprir determinadas demandas, o que em muitos casos, ocasiona o estresse ocupacional. Com o propósito de aprofundar conhecimentos sobre a relação existente entre o estresse e a atividade docente, fizemos o seguinte questionamento: quais os sintomas de estresse apresentados em professores do ensino superior? Com Objetivo geral de estudar os sintomas e níveis de estresse, relacionando-os à carreira docente do ensino superior, com as variáveis: regime de trabalho, vínculo institucional, idade, sexo, tempo de trabalho, tipo de IES, em uma população específica pertencente a duas Instituições de Ensino Superior -IES da cidade de Teresina, Estado do Piauí- Brasil, sendo uma pública e uma privada. Visando atingir os objetivos propostos, utilizamos da metodologia de caráter exploratório e descritivo, com abordagem quantitativa dos dados recorrendo à estatística descritiva. O instrumento de coleta de dados utilizado foi o “Inventário de Sintomas de Stress Lipp – ISSL” da autora Marilda Lipp (2000), aplicado em uma amostra de cem (100) professores, com idade entre 22 e 55 anos de idade. Mediante a análise dos dados, pode-se verificar que apesar das diferenças existentes entre IES públicas e privadas, a maioria dos resultados foram semelhantes. Em ambas as IES houve presença de estresse nos docentes, prevalecendo a fase de alerta, logo após a fase de resistência, em seguida a fase de quase-exaustão,Houve um predomínio de sintomas psicológicos, onde na IES privada se destacam: aumento súbito de motivação e entusiasmo súbito. E como sintomas físicos: boca seca e nó no estômago. Na IES públicas os sintomas psicológicos foram: entusiasmo súbito e aumento súbito de motivação. E físicos: tensão muscular e nó no estômago. Em relação as co-variáveis que apresentaram maior relação com o estresse pode-se apresentar na IES privada o sexo masculino e feminino possuem a mesma representatividade, a faixa etária de 31 a 39 anos, estado civil casado, tempo de serviço de 7 a 13 anos, jornada de trabalho integral e vínculo efetivo. Já na IES pública verifica-se relação com o sexo feminino, idade variando de 31 a 39 anos, estado civil solteiro, tempo de serviço de 7 a 13 anos, jornada de trabalho parcial e vínculo substituto. De acordo com o que foi analisado, percebe-se que os docentes do ensino superior, independente do tipo de IES ao qual estão vinculados, estão sujeitos ao estresse e que estes não devem ser responsabilizados pelo mesmo, nem por adoção de medidas preventivas, visto que toda a IES sofre as conseqüências, e tem condições de auxiliar o professor com situações preventivas, de controle a partir do conhecimento, interpretação e mudança de hábitos do professor no ambiente universitário. ABSTRACT: With globalization and its changes, the human being has suffered from stress while trying to adapt and monitor such events, within family, social, emotional or professional scope. To play as teacher in higher education, they are required various conditions and the teacher suffers physical and psychological wear trying to meet certain demands, which in many cases leads to occupational stress.Aiming to deepen knowledge about the relationship between stress and teaching activities, we made the following question: what are the symptoms of stress presented by higher education teachers? With the general objective of study the symptoms and the stress levels, linking them to the teaching career in higher education, using the following variables: working regime, institutional link, age, sex, working time, type of HEI, in a specific population belongs to two Higher Education Institutions HEI - of Teresina, Piauí, Brazil, one public and one private. Aiming to achieve the proposed objectives, we used a exploratory - descriptive study, with quantitative approach of data using graphs and tables. The data collection instrument used was the "Lipp Stress Symptoms Inventory - ISSL" by the author Marilda Lipp (2000), applied to a sample of a hundred (100) teachers, between 22 and 55 years of age. Through data analysis, despite the differences between public and private HEIs, we can see that the most results were similar. In both HEIs, the results revealed that the alert phase of stress had prevailed, followed by resistance and almost-exhaustion phases. A small number presented stress in exhaustion phase and another group did not present stress. There was a predominance of psychological symptoms, which in private HEIs stands out: increase of motivation and enthusiasm suddenly. And as physical symptoms: dry mouth and stomached. In public HEI, psychological symptoms were sudden enthusiasm and increse of motivation. And physical symptoms: muscle tension and stomached. In relation to the co-variables that showed a greater relationship with stress, in private HEIs males and females have the same representation, between 31-39 years, married, working time of 7-13 years, full working day and effective link. Already in public HEIs, female, between 31-39 years, unmarried, working time of 7-13 years, partial working day and substitute link had prevailed. According to analysis, we find that teachers in higher education, regardless of the HEI to which they are linked, are subject to stress. And they should not be blamed for the onset of stress, neither by adopting preventive measures, since all the HEI suffers the consequences, and it is able to help teachers with preventive measures based on the knowledge, interpretation and change habits of the teacher in the university environment.
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Catastrophic tsunamis are described in historical sources for all regions around the Gulf of Cadiz, at least since 60 BC. Most of the known events are associated with moderate to large earthquakes and among them the better studied is 1 November 1755. We present here a review of the events which effects, on the coasts of the Portuguese mainland and Madeira Island, are well described in historical documents or have been measured by tide gauges since the installation of these instruments. For a few we include new relevant information for the assessment of the tsunami generation or effects, and we discard events that are included in existing compilations but are not supported by quality historical sources or instrumental records. We quote the most relevant quantitative descriptions of tsunami effects on the Portuguese coast, including in all pertinent cases a critical review of the coeval sources, to establish a homogenous event list. When available, instrumental information is presented. We complement all this information with a summary of the conclusions established by paleo-tsunami research.
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In this abstract is presented an energy management system included in a SCADA system existent in a intelligent home. The system control the home energy resources according to the players definitions (electricity consumption and comfort levels), the electricity prices variation in real time mode and the DR events proposed by the aggregators.
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Dissertação apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Jornalismo.
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O intuito principal desta Tese é criar um interface de Dados entre uma fonte de informação e fornecimento de Rotas para turistas e disponibilizar essa informação através de um sistema móvel interactivo de navegação e visualização desses mesmos dados. O formato tecnológico será portátil e orientado à mobilidade (PDA) e deverá ser prático, intuitivo e multi-facetado, permitindo boa usabilidade a públicos de várias faixas etárias. Haverá uma componente de IA (Inteligência Artificial), que irá usar a informação fornecida para tomar decisões ponderadas tendo em conta uma diversidade de aspectos. O Sistema a desenvolver deverá ser, assim, capaz de lidar com imponderáveis (alterações de rota, gestão de horários, cancelamento de pontos de visita, novos pontos de visita) e, finalmente, deverá ajudar o turista a gerir o seu tempo entre Pontos de Interesse (POI – Points os Interest). Deverá também permitir seguir ou não um dado percurso pré-definido, havendo possibilidade de cenários de exploração de POIs, sugeridos a partir de sugestões in loco, similares a Locais incluídos no trajecto, que se enquadravam no perfil dos Utilizadores. O âmbito geográfico de teste deste projecto será a zona ribeirinha do porto, por ser um ex-líbris da cidade e, simultaneamente, uma zona com muitos desafios ao nível geográfico (com a inclinação) e ao nível do grande número de Eventos e Locais a visitar.
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Not a year goes by that we don't hear of another hazing scandal in a higher education institution. Many researchers took interest in this issue in order to understand its causes and consequences. They provided definitions and lead to prevent it. We found hazing in many social groups around the world, with different names, and under specific forms. This paper aims to better understand hazing and its actors, with a specific focus on hazing in higher education. We presented three definitions to offer several perspectives on hazing, and facilitate its apprehension. Our method was to analyze the relevant scientific literature with the intention of reflecting on its roots and representation among individuals. Results are an exposition of motivations from hazing's actors, recommendations about how to define it and how to prevent derivations. Our main conclusions assume hazing is usually depicted as a deviant behavior, but it would appear to be a norm. Also, its core purpose would be the progression from newcomer to a group member. A lack of structure or meaning could lead to its misuse and facilitate outrageous events. In higher education, hazing seems to be used as a tool to integrate freshmen in their new institutional world. Scandals including violence, sexual and alcohol abuse could be a symptom of something deeper from hazing's environment.
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O presente trabalho apresenta um estudo laboratorial que teve como finalidade o reconhecimento de perda de propriedades da madeira de edifícios antigos quando degradada por carunchos. Foi estudada madeira antiga de pinho e de choupo, com idades compreendidas entre 100 e 200 anos. Como abordagem inicial são apresentadas as características da madeira e dos edifícios pombalinos e gaioleiros onde esta era bastante usada, não só como elemento deacabamento, mas principalmente como elemento estrutural. São apresentados os vários fatores que levam à degradação da madeira assim como alguns métodos de avaliação e diagnóstico dos estados de conservação dos elementos de madeira que se encontram nos edifícios. É também desenvolvido um estudo sobre o caruncho grande e caruncho pequeno, seu ciclo de vida e forma como degrada a madeira, servindo de base ao estudo laboratorial. No desenvolvimento foi avaliado o estado de degradação de provetes de madeira antiga com 30 x 30 x 90 mm e de seguida correlacionado com a sua resistência à compressão, o seu módulo de elasticidade e a extensão em fase plástica. Desta forma pretende-se estudar o modo como os diferentes estados de degradação por caruncho influenciam as caraterísticas mecânicas das peças de madeira.
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The influence of uncertainties of input parameters on output response of composite structures is investigated in this paper. In particular, the effects of deviations in mechanical properties, ply angles, ply thickness and on applied loads are studied. The uncertainty propagation and the importance measure of input parameters are analysed using three different approaches: a first-order local method, a Global Sensitivity Analysis (GSA) supported by a variance-based method and an extension of local variance to estimate the global variance over the domain of inputs. Sample results are shown for a shell composite laminated structure built with different composite systems including multi-materials. The importance measures of input parameters on structural response based on numerical results are established and discussed as a function of the anisotropy of composite materials. Needs for global variance methods are discussed by comparing the results obtained from different proposed methodologies. The objective of this paper is to contribute for the use of GSA techniques together with low expensive local importance measures.
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Fiber reinforced plastics are increasing their importance as one of the most interesting groups of material on account of their low weight, high strength, and stiffness. To obtain good quality holes, it is important to identify the type of material, ply stacking sequence, and fiber orientation. In this article, the drilling of quasi-isotropic hybrid carbon +glass/epoxy plates is analyzed. Two commercial drills and a special step drill are compared considering the thrust force and delamination extension. Results suggest that the proposed step drill can be a suitable option in laminate drilling.