1000 resultados para teste de hipótese


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Apresenta um teste de laboratório para determinar a concentração inibitória mínima (CIM ou MIC, em inglês). Como agentes inibitórios são utilizados o sulfito de sódio e o sulfato de cobre, em cinco concentrações diferentes para cada um em uma bactéria contaminante da fermentação. É preparado o inóculo da bactéria, que é misturado ao caldo com nutrientes, água destilada e a solução do antimicrobiano, sendo uma amostra para cada concentração. É feita a leitura da absorbância inicial e, após o tempo de incubação, é feita a leitura da absorbância final. Como exercício, calcular a variação de absorbância para cada concentração. A concentração de antimicrobiano que causou a menor variação de absorbância é a concentração mínima inibitória deste antimicrobiano.

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O desenho da figura humana é um tipo de desenho realizado espontaneamente pelas crianças de diferentes culturas. Este pode ser encarado como medida não verbal da maturidade conceptual da criança. Ao longo dos tempos, na tentativa de construir um instrumento mais eficaz, vários autores desenvolveram diferentes sistemas de avaliação do Teste do Desenho da Figura Humana (TDFH). Assim, o objectivo desta investigação consiste na aferição e validação do TDFH à população portuguesa madeirense, utilizando o sistema de avaliação de Solange Wechsler (2003). Este teste propõe a aplicação de dois desenhos, uma figura masculina e outra feminina, que são cotados independentemente ao longo de 18 itens e 17 itens subdivididos respectivamente. Neste estudo participaram 489 sujeitos, 50,3% do sexo masculino e 49,7% do sexo feminino, com idades compreendidas entre os 5 e os 13 anos de idade da Região Autónoma da Madeira no ano lectivo 2009/2010. Os resultados mostram diferenças significativas na forma de desenhar a figura humana, entre os sexos, as faixas etárias e os anos escolares. Assim, as raparigas apresentam valores superiores aos dos rapazes; à medida que a idade avança os valores obtidos aumentam; e por fim à medida que as crianças progridem na escolaridade os resultados são superiores. Verificou-se ainda que alunos de escolas públicas apresentam resultados mais elevados do que os alunos de escolas privadas, sendo que alunos de escolas rurais expressam valores superiores aos das escolas urbanas. Os dados do TDFH apresentaram correlações positivas significativas com os das Matrizes Progressivas Coloridas de Raven, bem como com as classificações de Português e Matemática. Ao nível da consistência interna, o instrumento apresenta alphas de Cronbach entre os 0,80 e os 0,924, o que lhe confere fiabilidade. Globalmente, o TDFH apresenta bons valores de validade mostrando ser uma boa medida desenvolvimental e conceptual.

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ALVES, Janaína da Silva. Análise comparativa e teste empírico da validade dos modelos CAPM tradicional e condicional: o caso das ações da Petrobrás. Revista Ciências Administrativas, Fotaleza, v. 13, n. 1, p.147-157, ago. 2007.

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Forecast is the basis for making strategic, tactical and operational business decisions. In financial economics, several techniques have been used to predict the behavior of assets over the past decades.Thus, there are several methods to assist in the task of time series forecasting, however, conventional modeling techniques such as statistical models and those based on theoretical mathematical models have produced unsatisfactory predictions, increasing the number of studies in more advanced methods of prediction. Among these, the Artificial Neural Networks (ANN) are a relatively new and promising method for predicting business that shows a technique that has caused much interest in the financial environment and has been used successfully in a wide variety of financial modeling systems applications, in many cases proving its superiority over the statistical models ARIMA-GARCH. In this context, this study aimed to examine whether the ANNs are a more appropriate method for predicting the behavior of Indices in Capital Markets than the traditional methods of time series analysis. For this purpose we developed an quantitative study, from financial economic indices, and developed two models of RNA-type feedfoward supervised learning, whose structures consisted of 20 data in the input layer, 90 neurons in one hidden layer and one given as the output layer (Ibovespa). These models used backpropagation, an input activation function based on the tangent sigmoid and a linear output function. Since the aim of analyzing the adherence of the Method of Artificial Neural Networks to carry out predictions of the Ibovespa, we chose to perform this analysis by comparing results between this and Time Series Predictive Model GARCH, developing a GARCH model (1.1).Once applied both methods (ANN and GARCH) we conducted the results' analysis by comparing the results of the forecast with the historical data and by studying the forecast errors by the MSE, RMSE, MAE, Standard Deviation, the Theil's U and forecasting encompassing tests. It was found that the models developed by means of ANNs had lower MSE, RMSE and MAE than the GARCH (1,1) model and Theil U test indicated that the three models have smaller errors than those of a naïve forecast. Although the ANN based on returns have lower precision indicator values than those of ANN based on prices, the forecast encompassing test rejected the hypothesis that this model is better than that, indicating that the ANN models have a similar level of accuracy . It was concluded that for the data series studied the ANN models show a more appropriate Ibovespa forecasting than the traditional models of time series, represented by the GARCH model

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Dopamine (DA) is known to regulate both sleep and memory formations, while sleep plays a critical role in the consolidation of different types of memories. We believe that pharmacological manipulation of dopaminergic pathways might disrupt the sleep-wake cycle, leading to mnemonic deficits, which can be observed in both behavioral and molecular levels. Therefore, here we investigated how systemic injections of haloperidol (0.3 mg/kg), immediately after training in dark and light periods, affects learning assessed in the novel object preference test (NOPT) in mice. We also investigated the hippocampal levels of the plasticity-related proteins Zif-268, brain-derived neurotrophic factor (BDNF) and phosphorylated Ca2+/calmodulin-dependent protein kinases II (CaMKII-P) in non-exposed (naïve), vehicle-injected controls and haloperidol-treated mice at 3, 6 and 12 hours after training in the light period. Haloperidol administration during the light period led to a subsequent impairment in the NOPT. In contrast, preference was not observed during the dark period neither in mice injected with haloperidol, nor in vehicle-injected animals. A partial increase of CaMKII-P in the hippocampal field CA3 of vehicle-injected mice was detected at 3h. Haloperidol-treated mice showed a significant decrease in the dentate gyrus of CaMKII-P levels at 3, 6 and 12h; of Zif-268 levels at 6h, and of BDNF levels at 12h after training. Since the mnemonic effects of haloperidol were only observed in the light period when animals tend to sleep, we suggest that these effects are related to REM sleep disruption after haloperidol injection

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This document aims to improve the quality of the production test in vertical tanks with free water drain pipes, through a device to control the draining system. This proposal consists of an interface detector close to the tank bottle and a control valve on the pipe-drain; they are attached to a remote supervisor system, which will be minimizing the human influence in the conclusion of the test result. And for more consciousness the work shows the importance of the wells production test in the attendance and diagnosis of the productive process, informing the large number of tests executed and problems of the procedure adopted in the field today. There are many possible sources of uncertainty in this kind of test as shown in the experiments realized in the field; the object prototype of this dissertation will be made in the field, based upon the definition of parameters and characteristics of the devices proposal. For a better definition of the draining process the action results of the assessment test are shown, especially changed some for the understand ing of the real process. It shows the proposal details and the configuration that will be used in the tank of Monte Alegre s field Production Station, explaining the interface detector kind and the control system. It is the base to a pilot project now in development, named as the new project classified in the status of the new technology and production improvement of PETROBRAS in Rio Grande do Norte and Ceará. This dissertation concludes that the automation of the conventional test with the draining system will bring benefits both economically as metrologically, because it reduces the uncertainty of the test procedures with free water draining, and also decreases the number of tests with problems

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The aim of this study was to test the Ecological Apparency Hypothesis comparing two rural communities in João Câmara (RN) and Remigio (PB), in the Northeast of Brazil. This hypothesis assumes that plants are perceived, known and used by human populations according to their local availability. The most used species would be the ones that are more available in the forest (apparent), and apparently suffer greater pressure of use. Communities were consulted through semi-structured interviews. In Remigio 42 people were interviewed, and 50 in João Câmara. The importance of each species was evaluated considering the distinction between citations from current and potential uses. The ethnobotanical information was associated with phytosociological parameters collected by the point-centered quarter method in forested areas, where 50 transects were distributed in each community, and 4,000 individuals sampled in total. Based on the interviews, 58 useful species were recorded, 42 genera and18 families. In the phytosociological study 30 species, 22 genera and 12 families in João Câmara, In Remígio were identified 34 species, 22 genera and nine families.The species were grouped into 11 categories of use. The ecological appearance was confirmed only in the João Câmara, which best explained the relationship between local availability and use of timber resources. Positive correlations were observed also between the technology category VUpotential and dominance. The point-centered quarter was efficient to test appearance, however, further studies through the point-centered quarter method are recommended

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Alterations in the neuropsychomotor development of children are not rare and can manifest themselves with varying intensity at different stages of their development. In this context, maternal risk factors may contribute to the appearance of these alterations. A number of studies have reported that neuropsychomotor development diagnosis is not an easy task, especially in the basic public health network. Diagnosis requires effective, low-cost, and easy - to-apply procedures. The Denver Developmental Screening Test, first published in 1967, is currently used in several countries. It has been revised and renamed as the Denver II Test and meets the aforementioned criteria. Accordingly, the aim of this study was to apply the Denver II Test in order to verify the prevalence of suspected neuropsychomotor development delay in children between the ages of 0 and 12 months and correlate it with the following maternal risk factors: family income, schooling, age at pregnancy, drug use during pregnancy, gestational age, gestational problems, type of delivery and the desire to have children. For data collection, performed during the first 6 months of 2004, a clinical assessment was made of 398 children selected by pediatricians and the nursing team of each public health unit. Later, the parents or guardians were asked to complete a structured questionnaire to determine possible risk indicators of neuropsychomotor development delay. Finally the Denver II Developmental Screening Test (DDST) was applied. The data were analyzed together, using Statistical Package for Social Science (SPSS) software, version 6.1. The confidence interval was set at 95%. The Denver II Test yielded normal and questionable results. This suggests compromised neuropsychomotor development in the children examined and deserves further investigation. The correlation of the results with preestablished maternal risk variables (family income, mother s schooling, age at pregnancy, drug use during the pregnancy and gestational age) was strongly significant. The other maternal risk variables (gestational problems, type of delivery and desire to have children) were not significant. Using an adjusted logistic regression model, we obtained the estimate of the greater likelihood of a child having suspected neuropsychomotor development delay: a mother with _75 4 years of schooling, chronological age less than 20 years and a drug user during pregnancy. This study produced two manuscripts, one published in Acta Cirúrgica Brasileira , in which an analysis was performed of children with suspected neuropsychomotor development delay in the city of Natal, Brazil. The other paper (to be published) analyzed the magnitude of the independent variable maternal schooling associated to neuropsychomotor development delay, every 3 months during the first twelve months of life of the children selected.. The results of the present study reinforce the multifactorial characteristic of development and the cumulative effect of maternal risk factors, and show the need for a regional policy that promotes low-cost programs for the community, involving children at risk of neuropsychomotor development delay. Moreover, they suggest the need for better qualified health professionals in terms of monitoring child development. This was an inter- and multidisciplinary study with the integrated participation of doctors, nurses, nursing assistants and professionals from other areas, such as statisticians and information technology professionals, who met all the requirements of the Postgraduate Program in Health Sciences of the Federal University of Rio Grande do Norte

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Objective: The purpose of this study was to investigate the kinetics of this micronutrient in schoolchildren between the ages of 6 and 9 years, of both sexes, and to verify its sensitivity in detecting alterations in body zinc status. Methods: Nutritional assessment was performed by body mass index. Food intake, venous zinc tolerance test and zinc kinetics were carried out before and after 3-month oral zinc supplementation. Results: Of the 42 children studied, 76.2% had healthy weight. Only energy, calcium and fiber intake were suboptimal before and after oral zinc supplementation. Serum zinc and total-body zinc clearance, although at normal levels, increased significantly after zinc supplementation. Conclusion: We concluded, therefore, that kinetics is a sensitive tool for detecting changes in body zinc status, even in children without a deficiency of this mineral. Furthermore, kinetics showed a positive response to supplementation and may be a sensitive parameter to evaluate the efficacy of this therapy

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A escassez de instrumentos para a avaliação e a triagem da doença de Alzheimer, (DA), notadamente denominados de rastreio, com características de padronização e validados para o Nordeste, motivou este Estudo. Visando à triagem de uma etapa mais leve da doença e encaminhamento precoce ao tratamento multidisciplinar foi elaborado o Teste de Rastreio da Doença de Alzheimer com Provérbios (TRDAP), a partir de um Jogo de Memória de Provérbios, construído como recurso terapêutico ocupacional. Está composto de três etapas conforme a função neuropsicológica avaliada, a A (memória de curto prazo), B (funções executivas e linguagem) e C (memória episódica), além do reconhecimento de provérbios. O Estudo foi realizado em uma amostra de conveniência, com 91 idosos (28 DA e 63 controles), a partir de 60 anos, com um ou mais anos de escolaridade. Foram controladas as variáveis, como doenças intercorrentes ou déficits sensoriais que pudessem comprometer o desempenho dos pacientes, nos testes. O protocolo constou de oito testes selecionados por especialistas: Miniexame do Estado Mental (para validade convergente), Escala de Depressão Geriátrica EDG (validade discriminante), Lista de Palavras, Fluência Verbal, Span de Dígitos, Figura Neuropsi, Teste do Relógio, Atividade de Vida Diária e Instrumental. Os resultados confirmaram a validade de construto convergente e discriminante, assim como a relação significativa (p<0,005) com todos os testes, exceto com o EDG. Quanto à validade concorrente, não houve discordância com o critério da avaliação médica observou-se consistência interna aceitável, conferindo confiabilidade no instrumento, o que não ocorreu com MEEM. Tais resultados permitem afirmar que o TRDAP possui características psicométricas, adequadas ao rastreio da fase leve da DA para população estudada