938 resultados para regression ana-lysis
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The objective of this study was to estimate (co)variance components using random regression on B-spline functions to weight records obtained from birth to adulthood. A total of 82 064 weight records of 8145 females obtained from the data bank of the Nellore Breeding Program (PMGRN/Nellore Brazil) which started in 1987, were used. The models included direct additive and maternal genetic effects and animal and maternal permanent environmental effects as random. Contemporary group and dam age at calving (linear and quadratic effect) were included as fixed effects, and orthogonal Legendre polynomials of age (cubic regression) were considered as random covariate. The random effects were modeled using B-spline functions considering linear, quadratic and cubic polynomials for each individual segment. Residual variances were grouped in five age classes. Direct additive genetic and animal permanent environmental effects were modeled using up to seven knots (six segments). A single segment with two knots at the end points of the curve was used for the estimation of maternal genetic and maternal permanent environmental effects. A total of 15 models were studied, with the number of parameters ranging from 17 to 81. The models that used B-splines were compared with multi-trait analyses with nine weight traits and to a random regression model that used orthogonal Legendre polynomials. A model fitting quadratic B-splines, with four knots or three segments for direct additive genetic effect and animal permanent environmental effect and two knots for maternal additive genetic effect and maternal permanent environmental effect, was the most appropriate and parsimonious model to describe the covariance structure of the data. Selection for higher weight, such as at young ages, should be performed taking into account an increase in mature cow weight. Particularly, this is important in most of Nellore beef cattle production systems, where the cow herd is maintained on range conditions. There is limited modification of the growth curve of Nellore cattle with respect to the aim of selecting them for rapid growth at young ages while maintaining constant adult weight.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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O objetivo deste estudo foi estimar a prevalência das mal-oclusões e variáveis a elas associadas, como hábitos deletérios (HD) e as alterações oronasofaringianas (AO), respiração bucal, deglutição atípica e fonação atípica, em crianças com idade de três anos, no Município de Vitória, Espírito Santo, Brasil. A amostra constituiu-se de 291 crianças de ambos os sexos, matriculadas nos Centros de Educação Infantil, selecionadas por meio de amostragem probabilística por conglomerados. A análise de regressão logística indicou maior risco relativo (RR) de crianças com sobressaliência alterada, mordida aberta e mordida cruzada, em apresentar: respiração bucal (RR = 1,89; IC: 1,56-2,03), (RR = 2,46; IC: 2,00-3,02), (RR = 1,45; IC: 1,23-1,72); deglutição atípica (RR = 2,57; IC: 1,87-3,52), (RR = 3,49; IC: 2,53-4,81), (RR = 1,86; IC: 1,46-2,39) e fonação atípica (RR = 2,25; IC: 1,66-3,05), (RR = 3,18; IC: 2,38-4,25), (RR = 1,71; IC: 1,32-2,22), respectivamente. Foi mostrado haver associação entre sucção de dedo e de chupeta com sobressaliência alterada (p < 0,001) e sucção de chupeta e mordida aberta (p < 0,001). Esses resultados indicam que a prevalência das mal-oclusões está associada aos HD e às AO.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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INTRODUÇÃO: A malaria é uma doença endêmica na região da Amazônia Brasileira, e a detecção de possíveis fatores de risco pode ser de grande interesse às autoridades em saúde pública. O objetivo deste artigo é investigar a associação entre variáveis ambientais e os registros anuais de malária na região amazônica usando métodos bayesianos espaço-temporais. MÉTODOS: Utilizaram-se modelos de regressão espaço-temporais de Poisson para analisar os dados anuais de contagem de casos de malária entre os anos de 1999 a 2008, considerando a presença de alguns fatores como a taxa de desflorestamento. em uma abordagem bayesiana, as inferências foram obtidas por métodos Monte Carlo em cadeias de Markov (MCMC) que simularam amostras para a distribuição conjunta a posteriori de interesse. A discriminação de diferentes modelos também foi discutida. RESULTADOS: O modelo aqui proposto sugeriu que a taxa de desflorestamento, o número de habitants por km² e o índice de desenvolvimento humano (IDH) são importantes para a predição de casos de malária. CONCLUSÕES: É possível concluir que o desenvolvimento humano, o crescimento populacional, o desflorestamento e as alterações ecológicas associadas a estes fatores estão associados ao aumento do risco de malária. Pode-se ainda concluir que o uso de modelos de regressão de Poisson que capturam o efeito temporal e espacial em um enfoque bayesiano é uma boa estratégia para modelar dados de contagem de malária.
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La présente thèse est une approche critique de la production littéraire de l écrivain carioca Ana Cristina Cesar. Aussi bien dans la poésie que dans son oeuvre critique, Ana Cristina Cesar a mis en évidence la question de l écriture comme le principal dilème de son projet comme écrivain. En face d autant de registres, soit en forme de poèmes, texte critique ou lettres, la question de l écriture est, dans l ensemble de son oeuvre, formulée à partir d une interpénétration entre la littérature et la vie. Considérant le problème de l écriture comme partie d un projet de l être écrivain pour Ana Cristina Cesar, nous affirmons que l intérêt de notre recherche se dirige vers l analyse des manières selon lesquelles ce problème parcourt son écriture et dévient une question métalinguistique dans sa création. Nous partons de la réflexion sur l écriture dans son oeuvre pour relever la question principale de notre proposition de travail avec son texte: Qu est-ce que c est, après tout, écrire pour Ana Cristina Cesar et comment cela se formule-t-il dans la production des rôles qu elle exerce en tant que poète, critique et professeur? Parmi les principaux objectifs qui guident cette recherche sont: promouvoir un dialogue avec les textes de l auteur, où se présente le problème de l écrire, à travers une réflexion sur le parcours de son activité intellectuelle, pour elle imprégné de questions sur l écriture féminine et la production marginale; et enquêter les manières dont cette réflexion s articule dans les fonctions qu elle développe comme poète, critique et professeur et les rélations qu elle établi avec la littérature de son époque. En outre, nous discuterons l importance de son oeuvre dans la littérature marginale, ce qui possibilite aussi une évaluation de cette production dans la littérature brésilienne
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The frailty in the elderly is characterized by decreased physiological reserves, and is associated with increased risk of disability and high vulnerability to morbidity and mortality. This study is part of a multicentric project on Frailty in Elderly Brazilians (REDE FIBRA). Aims: to investigate characteristics, prevalence and associated factors related to frailty. Metodology: We interviewed 391 elderly patients aged 65 years, selected randomly. Data collection was performed using a multidimensional questionnaire containing information about socio-demographic and clinical variables. To characterize the frail elderly, was considered the phenotype proposed by Fried. Data were analyzed using descriptive statistics, bivariate analysis (χ ²) and binary logistic regression. Results: The prevalence of frailty was 17.1%. In the final model of multivariate analysis, was obtained as factors associated with frailty: advanced chronological age (p <0.001), have comorbidity (p <0.035), show dependence on performing basic activities of daily living (p <0.010) and instrumental (p <0.003) and have poor perception of health status (p <0030). Conclusions: The factors associated with frailty suggest a predictive model helping to understand the syndrome, guiding actions that minimize adverse effects on the aging process
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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In this paper, we proposed a flexible cure rate survival model by assuming the number of competing causes of the event of interest following the Conway-Maxwell distribution and the time for the event to follow the generalized gamma distribution. This distribution can be used to model survival data when the hazard rate function is increasing, decreasing, bathtub and unimodal-shaped including some distributions commonly used in lifetime analysis as particular cases. Some appropriate matrices are derived in order to evaluate local influence on the estimates of the parameters by considering different perturbations, and some global influence measurements are also investigated. Finally, data set from the medical area is analysed.
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ABSTRACT Introduction: The cerebrovascular accident (CVA) is an important cause of neurological impairment. Few data about the factors associated with morbidity of cerebrovascular accident are found in Brazil. Objectives: Evaluate sociodemographic characteristics, sleep habits, cognitive and functional status of patients with cerebrovascular accident. Methods: The patients evaluated through questionnaire Step 1 to survey the sociodemographic characteristics and Modified Rankin Scale for functional assessment. The neurological degree was evaluated by the National Institutes of Health Stroke Scale (NIHSS), the sleep Habits questionnaire for sleep and cognitive status by the Mini-Examination of the Mental State (MEMS). The data were analyzed using the chi-square test to determine differences in proportions of variables and linear regression analysis. Results: 305 patients were evaluated and the larger number of subjects was between 50 and 69 years (40%), most patients had no formal education (40.3%) and had ischemic type of cerebrovascular accident (72.5%). In the analysis of the functionality it was found that most patients had moderate impairment (55.1%). The results of the sleep habits showed that 63,6% of patients had one more person in the bedroom,12,3% complained about too much noise in the 11 room and 35% of too much light. From these patients 5,8% were smokers, 7,8% and 70,1% drank coffee drinkers, 28,6% had difficulty in initiate to sleep and woke up 37,6% in the middle of the night. Were showed complaints about nightmares (11%), feeling of suffocation (37,7%) and 35% felt very sleepy during the day. In addition, 95% were unemployed, 80,5% did not perform physical activities and 95,4% did not perform mental activities. The cognitive screening conducted a determined association of cognitive status with age and education level and neurological status. Conclusion: The study showed a high frequency of cases of cerebrovascular accident with functional dependence in a moderate degree, identified that many patients do not follow hygienic measures of sleep and found that the assessment of cognitive deficits must take into consideration the age, educational level and degree of neurological patients. We suggest the need for programs of assistance to victims of cerebrovascular accident patients, with a multidimensional approach including the rehabilitation team, the role of sleep medicine and Neuropsychology, so that patients have access to a more appropriate functional rehabilitation, develop a lifestyle that ensures a good sleep quality and are evaluated and rehabilitated with regard to cognitive impairment
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)