Neste trabalho, é apresentado vários métodos de diagnóstico para modelos de riscos múltiplos. A vantagem desse modelo é sua flexibilidade em relação aos modelos de risco simples, como, os modelos Weibull e log-logístico, pois acomoda uma grande classe de funções de risco, função de risco não-monótona, por exemplo, forma de "banheira" e curvas multimodal. Alguns métodos de influência, assim como, a influência local, influência local total de um indivíduo são calculadas, analizadas e discutidas. Uma discussão computacional do método do afastamento da verossimilhança, bem como da curvatura normal em influência local são apresentados. Finalmente, um conjunto de dados reais é usado para ilustrar a teoria estudada. Uma análise de resíduo é aplicada para a seleção do modelo apropriado. / In this paperwork is present various diagnostic methods for polyhazard models. Polyhazard models are a flexible family for fitting lifetime data. Their main advantage over the single hazard models, such as the Weibull and the log-logistic models, is to include a large amount of nonmonotone hazard shapes, as bathtub and multimodal curves. Some influence methods, such as the local influence, total local influence of an individual are derived, analyzed and discussed. A discussion of the computation of the likelihood displacement as well as the normal curvature in the local influence method are presented. Finally, an example with real data is given for illustration. A residual analysis is performed in order to select an appropriate model.

Made available in DSpace on 2016-04-25T20:21:07Z (GMT). No. of bitstreams: 1 Mamerto Granja Garcia.pdf: 3048919 bytes, checksum: b442a16b24cfc59b90c080c63cc574cc (MD5) Previous issue date: 2014-03-24 / Understand the electoral process and to identify the variables explicitly or implicitly involved remains a field full of mysteries as dark as the human mind. Psychosocial factors awakened in the election period refer the researcher to an environment full of symbols , the most unusual emotions and diverse interests that include a search undertaken by the voter , apparently rational , in order to find convergence between their personal aspirations and potential characteristics representative . This paper aims to outline considerations on the subject based on an analysis of voter behavior from three factors that stand out during the election process: indecision, the continuity and the candidate. Indecision will be analyzed from a survey of undecided voters indicated in several polls. It is demonstrated that the simple fact of being located in the stratum of the undecided voter presents trends vote for a particular candidate. On the topic continuity and candidate assesses the issue of parliamentarians that keeps on elective position for long periods, through successive re-elections, and in addition, an analysis of the candidate's profile and its effect on the voter's decision. To all these questions, appropriate quantitative models are used, which seek to create a bridge between research in the social sciences and the analysis of observations by means of statistical / Compreender o processo eleitoral e identificar as variáveis explicitamente ou implicitamente envolvidas continua sendo um campo repleto de mistérios tão obscuros quanto a mente humana. Os fatores psicossociais despertados no período eleitoral remetem o pesquisador a um ambiente repleto de simbologias, as mais inusitadas emoções e interesses diversos que compreendem uma busca empreendida pelo eleitor, aparentemente racional, no sentido de encontrar convergência entre seus anseios pessoais e as características do potencial representante. Este trabalho tem como objetivo delinear considerações sobre o tema com base em uma análise do comportamento do eleitor a partir de três fatores que se destacam durante o processo eleitoral: a indecisão, a continuidade e o candidato. A indecisão será analisada a partir do levantamento dos eleitores indecisos apontados em diversas pesquisas eleitorais. Demonstra-se que pelo simples fato de se situar no estrato dos indecisos, o eleitor apresenta tendências de voto para determinado candidato. No tópico continuidade e candidato, avalia-se a questão dos parlamentares que se mantem no cargo eletivo por longos períodos, através de sucessivas reeleições e como complemento, é feita uma análise do perfil do candidato e seus efeitos na decisão do eleitor. Para todas essas questões, são utilizados modelos quantitativos apropriados, os quais buscam criar uma ponte entre a pesquisa nas Ciências Sociais e a análise das observações por meio de ferramentas estatísticas

Submitted by Maria Aparecida (cidazen@gmail.com) on 2017-09-19T19:11:52Z No. of bitstreams: 1 Adriana Oliveira Dias.pdf: 39950781 bytes, checksum: f142c060796cb141f6fde41ca1c3dd5d (MD5) / Made available in DSpace on 2017-09-19T19:11:52Z (GMT). No. of bitstreams: 1 Adriana Oliveira Dias.pdf: 39950781 bytes, checksum: f142c060796cb141f6fde41ca1c3dd5d (MD5) Previous issue date: 2016-02-29 / Pregnancy and motherhood has been increasingly under investigation by the scientific community, with the risk of developing psychopathology, thus becoming a major public health problem for the mother-child dyad. This study had two objectives: to analyze the effects of psychosocial factors in the mother-child relationship; and analyze the psychometric properties of the Population Screening Scale for Depression (CES-D) to measure symptoms of depression in pregnant women both held in the city of Sao Luís-MA. In the first article, we used the Postpartum Bonding Questionnaire (PBQ) to assess the mother-child relationship in 1140 mother-child pairs. In the proposed model, socioeconomic status determined demographic, maternal psychosocial and social support, which determined the outcome of mother-child relationship, analyzed as latent variable. The models were adjusted for structural equation modeling using mplus 7.0. The final model had good fit (RMSEA = 0.047, CFI = 0.984; TLI = 0.981). The models of the first and second article were estimated by the method of least squares (WLSMV) adjusted for mean and variance. In the second article, the Exploratory Factor Analysis suggested models with up to four dimensions, with good adjustment only for models with 3 and 4 dimensions. In addition to these models were tested on Confirmatory Factor Analysis of the reference models and new model without items 4 and 8, which had low factor loadings (<0.40). if found to have symptoms of depression during pregnancy and postpartum presented more often, mother-child relationship impaired. These effects were direct and positive. The greatest effect was the symptoms of depression during pregnancy. They associated themselves also to impaired mother-child relationship, less social support, unfavorable socioeconomic status and marital status informal, indirect pathway. Symptoms of anxiety and maternal age showed no effect on the mother-child relationship. It was found that models with four dimensions were suitable to assess symptoms of depression in pregnant women in the city of São Luís. It is confirmed using the CES-D to measure symptoms of depression in pregnant women, considering its practical use, as a scale with good fit index. It was also observed that greater attention to the womwn health of during the prenatal and postpartum may be a strategy for identifying psychopathological symptoms, in order to prevent possible damage in the mother-child relationship. / A gestação e a maternidade têm sido, cada vez mais, alvo de investigação por parte da comunidade científica, pelo risco de desenvolvimento de psicopatologia, constituindo-se em um importante problema de saúde pública para a díade mãe-filho. O presente estudo teve dois objetivos: analisar efeitos de aspectos psicossociais na relação mãe-filho; e analisar as propriedades psicométricas da Escala de Rastreamento Populacional para Depressão (CES-D) para medir sintomas de depressão em gestantes; ambos realizados na cidade de São Luís-MA. No primeiro artigo, utilizou-se o Postpartum Bonding Questionnaire (PBQ) para avaliar a relação mãe-filho em 1140 pares mãe-filho. No modelo proposto, situação socioeconômica determinou fatores demográficos, psicossociais maternos e de apoio social, que determinaram o desfecho relação mãe-filho, analisada como variável latente. Os modelos foram ajustados por modelagem de equações estruturais, utilizando o MPLUS 7.0. O modelo final teve bom ajuste (RMSEA=0.047; CFI=0.984; TLI =0.981). Os modelos do primeiro e do segundo artigo foram estimados pelo método dos mínimos quadrados (WLSMV) ajustados pela média e variância. No segundo artigo, a Análise Fatorial Exploratória sugeriu modelos com até quatro dimensões, com bom ajuste apenas para os modelos com 3 e 4 dimensões. Além desses modelos, foram testados na Análise Fatorial Confirmatória os modelos de referência e um novo modelo, sem os itens 4 e 8, que apresentaram cargas fatoriais baixas (<0,40). Constataram-se que os sintomas de depressão na gestação e pós-parto apresentaram, mais frequentemente, relação mãe-filho prejudicada. Esses efeitos foram direto e positivo. O maior efeito foi dos sintomas de depressão na gestação. Associaram-se também à relação mãe-filho prejudicada, menor apoio social, situação socioeconômica desfavorável e situação conjugal informal, via indireta. Sintomas de ansiedade e idade materna não apresentaram efeito na relação mãe-filho. Verificou-se que os modelos com quatro dimensões se mostraram adequados para avaliar sintomas de depressão em gestantes na cidade de São Luís. Confirma-se a utilização da CES-D para medir sintomas de depressão em gestantes, considerando sua utilidade prática, por ser uma escala com bom índice de ajuste. Observou-se também que uma maior atenção à saúde de mulheres durante o pré-natal e nos pós-parto pode ser uma estratégia para a identificação de sintomas psicopatológicos, com o intuito de prevenir possíveis prejuízos na relação mãe-filho.

Made available in DSpace on 2016-04-26T14:54:40Z (GMT). No. of bitstreams: 1 Mamerto Granja Garcia.pdf: 3048919 bytes, checksum: b442a16b24cfc59b90c080c63cc574cc (MD5) Previous issue date: 2014-03-24 / Understand the electoral process and to identify the variables explicitly or implicitly involved remains a field full of mysteries as dark as the human mind. Psychosocial factors awakened in the election period refer the researcher to an environment full of symbols , the most unusual emotions and diverse interests that include a search undertaken by the voter , apparently rational , in order to find convergence between their personal aspirations and potential characteristics representative . This paper aims to outline considerations on the subject based on an analysis of voter behavior from three factors that stand out during the election process: indecision, the continuity and the candidate. Indecision will be analyzed from a survey of undecided voters indicated in several polls. It is demonstrated that the simple fact of being located in the stratum of the undecided voter presents trends vote for a particular candidate. On the topic continuity and candidate assesses the issue of parliamentarians that keeps on elective position for long periods, through successive re-elections, and in addition, an analysis of the candidate's profile and its effect on the voter's decision. To all these questions, appropriate quantitative models are used, which seek to create a bridge between research in the social sciences and the analysis of observations by means of statistical / Compreender o processo eleitoral e identificar as variáveis explicitamente ou implicitamente envolvidas continua sendo um campo repleto de mistérios tão obscuros quanto a mente humana. Os fatores psicossociais despertados no período eleitoral remetem o pesquisador a um ambiente repleto de simbologias, as mais inusitadas emoções e interesses diversos que compreendem uma busca empreendida pelo eleitor, aparentemente racional, no sentido de encontrar convergência entre seus anseios pessoais e as características do potencial representante. Este trabalho tem como objetivo delinear considerações sobre o tema com base em uma análise do comportamento do eleitor a partir de três fatores que se destacam durante o processo eleitoral: a indecisão, a continuidade e o candidato. A indecisão será analisada a partir do levantamento dos eleitores indecisos apontados em diversas pesquisas eleitorais. Demonstra-se que pelo simples fato de se situar no estrato dos indecisos, o eleitor apresenta tendências de voto para determinado candidato. No tópico continuidade e candidato, avalia-se a questão dos parlamentares que se mantem no cargo eletivo por longos períodos, através de sucessivas reeleições e como complemento, é feita uma análise do perfil do candidato e seus efeitos na decisão do eleitor. Para todas essas questões, são utilizados modelos quantitativos apropriados, os quais buscam criar uma ponte entre a pesquisa nas Ciências Sociais e a análise das observações por meio de ferramentas estatísticas

A tuberculose continua sendo um problema de saúde publica, apesar dos avanços científicos, da evolução do tratamento e da descoberta de vacina. O presente estudo tem como intuito descrever a distribuição temporal da doença para os casos novos notificados nos municípios com mais de 200.000 habitantes no Estado de São Paulo (centros regionais), no período de janeiro de 2009 a dezembro de 2013, além de identificar algumas covariáveis socioeconômicas, demográficas e de saúde, que podem estar associadas com a doença e utilizar estas variáveis em diferentes modelos estatísticos para serem usados na previsão mensal de novos casos reportados no SINAN (Sistema de Informação de Agravos de Notificação). Alguns modelos estatísticos especiais foram utilizados na análise dos dados: modelos de regressão linear múltipla para os dados agrupados de contagem para todas as cidades ou cidades individuais transformados para uma escala logarítmica ou para as taxas de novos casos de tuberculose para todas as cidades nos 60 meses de acompanhamento e modelos de regressão de Poisson para dados de contagem. As inferências de interesse foram obtidas sob uma abordagem clássica e bayesiana e sob diferentes estruturas para as covariáveis e efeitos aleatórios que capturam a possível dependência das contagens de tuberculose nos 60 meses de acompanhamento. As previsões obtidas pelos modelos são comparadas com os dados reais para a procura de melhores modelos para serem ajustados pelos dados. / Tuberculosis remains a public health problem, despite scientific advances, the development of treatment and vaccine discovery. This study is intended to describe the temporal distribution of the new cases of the disease reported in cities with more than 200,000 inhabitants in the state of São Paulo (regional centers), from January 2009 to December 2013, and to identify some socio-economic, demographic and health covariates that may be associated with the disease and use these variables in different statistical models for use in the monthly forecast of new cases reported in the SINAN (Diseases Information notification System). Some special statistical models were used in the data analysis: multiple linear regression models for the pooled data count for all cities or individual cities transformed to a logarithmic scale or the rates of new cases of tuberculosis for all cities in the 60 months monitoring time and Poisson regression models for count data. Inferences of interest were obtained under a classical and a Bayesian approach and under different structures for covariates and random effects that capture the possible dependence of tuberculosis counts in the 60 months follow-up. The forecasts obtained by the models are compared with the actual data for the search of better models to be fitted by the data.

The study of cardiac action potentials has many medical applications. Dr. Dennis Noble first used mathematical models to study cardiac action potentials in the 1960s. We begin our study of cardiac action potentials with one form of the Fitzhugh-Nagumo partial differential equation. We use the non-classical method to produce a closed form solution for the decoupled Fitzhugh Nagumo equation. Using voltage recording data of action potentials in a cardiac myocyte and in purkinje fibers, we estimate parameter values for the closed form solution with standard linear and non-linear regression methods. Results are limited, thus leading us to perturb the solution to obtain a better fit. We turn to singular perturbation theory to justify our pole-based approach. Finally, we test our model on independent action potential data sets to evaluate our model and to draw conclusions on how our model can be applied.

In this paper, we study a new family of random variables, that arise as the distribution of extrema of a random number N of independent and identically distributed random variables X1,X2, ..., XN, where each Xi has a common continuous distribution with support on [0,1]. The general scheme is first outlined, and SUG and CSUG models are introduced in detail where Xi is distributed as U[0,1]. Some features of the proposed distributions can be studied via its mean, variance, moments and moment-generating function. Moreover, we make some other choices for the continuous random variables such as Arcsine, Topp-Leone, and N is chosen to be Geometric or Zipf. Wherever appropriate, we estimate of the parameter in the one-parameter family in question and test the hypotheses about the parameter. In the last section, two permutation distributions are introduced and studied.

Traditional approaches to predicting financial market dynamics tend to be linear and stationary, whereas financial time series data is increasingly nonlinear and non-stationary. Lately, advances in dynamical systems theory have enabled the extraction of complex dynamics from time series data. These developments include theory of time delay embedding and phase space reconstruction of dynamical systems from a scalar time series. In this thesis, a time delay embedding approach for predicting intraday stock or stock index movement is developed. The approach combines methods of nonlinear time series analysis with those of causality testing, theory of dynamical systems and machine learning (artificial neural networks). The approach is then applied to the Standard and Poors Index, and the results from our method are compared to traditional methods applied to the same data set.

The continued study of asymptomatic Ebolavirus infection is necessary to develop a more complete understanding of Ebola transmission dynamics. This paper conducts a meta-analysis of eight studies that measure seroprevalence (the number of subjects that test positive for anti-Ebolavirus antibodies in their blood) in subjects with household exposure or known case-contact with Ebola, but that have shown no symptoms. In our two random effects Bayesian hierarchical models, we find estimated seroprevalences of 8.76% and 9.72%, significantly higher than the 3.3% found by a previous meta-analysis of these eight studies. We also produce a variation of this meta-analysis where we exclude two of the eight studies. In this model, we find an estimated seroprevalence of 4.4%, much lower than our first two Bayesian hierarchical models. We believe a random effects model more accurately reflects the heterogeneity between studies and thus asymptomatic Ebola is more seroprevalent than previously believed among subjects with household exposure or known case-contact. However, a strong conclusion cannot be reached on the seriousness of asymptomatic Ebola without an international testing standard and more data collection using this adopted standard.

It is estimated that Periodontal Diseases effects up to 90% of the adult population. Given the complexity of the host environment, many factors contribute to expression of the disease. Age, Gender, Socioeconomic Status, Smoking Status, and Race/Ethnicity are all known risk factors, as well as a handful of known comorbidities. Certain vitamins and minerals have been shown to be protective for the disease, while some toxins and chemicals have been associated with an increased prevalence. The role of toxins, chemicals, vitamins, and minerals in relation to disease is believed to be complex and potentially modified by known risk factors. A large comprehensive dataset from 1999-2003 from the National Health and Nutrition Examination Survey (NHANES) contains full and partial mouth examinations on subjects for measurement of periodontal diseases as well as patient demographic information and approximately 150 environmental variables. In this dissertation, a Feasible Solution Algorithm (FSA) will be used to investigate statistical interactions of these various chemical and environmental variables related to periodontal disease. This sequential algorithm can be used on traditional statistical modeling methods to explore two and three way interactions related to the outcome of interest. FSA can also be used to identify unique subgroups of patients where periodontitis is most (or least) prevalent. In this dissertation, FSA is used to explore the NHANES data and suggest interesting relationships between the toxins, chemicals, vitamins, minerals and known risk factors that have not been previously identified.