978 resultados para Working Models


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Suppose that we are interested in establishing simple, but reliable rules for predicting future t-year survivors via censored regression models. In this article, we present inference procedures for evaluating such binary classification rules based on various prediction precision measures quantified by the overall misclassification rate, sensitivity and specificity, and positive and negative predictive values. Specifically, under various working models we derive consistent estimators for the above measures via substitution and cross validation estimation procedures. Furthermore, we provide large sample approximations to the distributions of these nonsmooth estimators without assuming that the working model is correctly specified. Confidence intervals, for example, for the difference of the precision measures between two competing rules can then be constructed. All the proposals are illustrated with two real examples and their finite sample properties are evaluated via a simulation study.

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In recent years, researchers in the health and social sciences have become increasingly interested in mediation analysis. Specifically, upon establishing a non-null total effect of an exposure, investigators routinely wish to make inferences about the direct (indirect) pathway of the effect of the exposure not through (through) a mediator variable that occurs subsequently to the exposure and prior to the outcome. Natural direct and indirect effects are of particular interest as they generally combine to produce the total effect of the exposure and therefore provide insight on the mechanism by which it operates to produce the outcome. A semiparametric theory has recently been proposed to make inferences about marginal mean natural direct and indirect effects in observational studies (Tchetgen Tchetgen and Shpitser, 2011), which delivers multiply robust locally efficient estimators of the marginal direct and indirect effects, and thus generalizes previous results for total effects to the mediation setting. In this paper we extend the new theory to handle a setting in which a parametric model for the natural direct (indirect) effect within levels of pre-exposure variables is specified and the model for the observed data likelihood is otherwise unrestricted. We show that estimation is generally not feasible in this model because of the curse of dimensionality associated with the required estimation of auxiliary conditional densities or expectations, given high-dimensional covariates. We thus consider multiply robust estimation and propose a more general model which assumes a subset but not all of several working models holds.

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The relations among measures of attachment, spouse behavior, and marital satisfaction were assessed in a broad sample of 193 married couples, using both questionnaire and diary methods. Insecure attachment was associated with less favorable reports of spouse behavior, as assessed by diary checklists. Marital satisfaction was predicted by attachment treasures and reports of spouse behavior. The relation between attachment security and marital satisfaction was moderated, but not mediated, by reported spouse behavior. Specifically, insecure individuals' evaluations of their relationships were more reactive to recent spouse behavior, an effect that was especially marked for fearful participants and for those in longer-term marriages. Some gender differences in patterns of prediction were obtained. The results are discussed in terms of the working models associated with attachment styles, and the processes by which relationship satisfaction may be eroded over time.

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Issues concerning the influence of attachment characteristics on own and partner's disclosure were addressed using a sample of 113 couples in medium-term dating relationships. Individual differences in attachment were assessed in terms of relationship anxiety and avoidance. Disposition to disclose was assessed using questionnaire measures of self-disclosure, relationship-focused disclosure, and the ability to elicit disclosure from the partner; in addition, structured diaries were used to assess aspects of disclosure (amount, intimacy, emotional tone, and satisfaction) in the context of couples' everyday interactions. Couple-level analyses showed that avoidance strongly predicted dispositional measures of disclosure, whereas anxiety (particularly partner's anxiety) was related to negative evaluations of everyday interactions. Interactive effects of attachment dimensions and gender were also obtained, highlighting the complexity of communication behavior. The results are discussed in terms of the goals and strategies associated with working models of attachment.

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Relatório de Prática Clínica apresentado à Escola Superior de Saúde Dr. Lopes Dias do Instituto Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Cuidados Paliativos, realizada sob a orientação científica do Professora Doutora Ana Paula Gonçalves Antunes Sapeta, do Instituto Politécnico de Castelo Branco.

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Dissertação de Mestrado apresentada ao ISPA - Instituto Universitário

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Dissertação de mestrado em Psicologia Aplicada

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El objetivo de esta investigación fue examinar la confiabilidad y validez del instrumento de evaluación de apego en el adulto, "Cartes: Modèles Individuels de Relation (CAMIR), en la realidad sociocultural chilena. Este instrumento, basado en la teoría del apego, es un cuestionario de auto-reporte que evalúa los modelos operativos internos en adultos y otras escalas relacionadas al apego. Los participantes fueron 578 sujetos, 204 hombres y 374 mujeres, con edades entre 14 y 80 años. Los sujetos completaron el CAMIR y medidas de vínculo y sintomatología actual, a través del Parental Bonding Instrument (PBI) and Outcome Questionnaire OQ-45.2. A través del análisis estadístico de los resultados se evaluaron las características psicométricas del test y de analiz ó la posibilidad de generar normas locales para la prueba. Los resultados confirmaron que el CAMIR es un instrumento confiable y válido en la evaluación de los modelos internos de relación en adultos. This study was designed to estimate the validity and reliability of the "Cartes: Modèles Individuels de Relation (CAMIR), in Chile. This inventory, based on attachment's theory, it's a auto-questionnaire evaluates the working models in adults and other scales relating to attachment. Participants were 578 individuals, 204 males and 374 females, 14 a 80 years old. Individuals completed the CAMIR and measures of bond and actual symptoms, with the Parental Bonding Instrument (PBI) and Outcome Questionnaire OQ-45.2. The general norms were obtained according to a statistical analysis of the results and to an evaluation of the psychometric characteristics of the test. The results confirmed that the psychometric characteristics of the CAMIR make it a reliable and valid tool to assess working models in adults.

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Bowlby proposed that the individual's social experiences, as early as in infancy, contribute to the construction of Internal Working Models (IWMs) of attachment, which will later guide the individual's expectations and behaviors in close relationships all along his or her life. The qualitative, individual characteristics of these models reflect the specificity of the individual's early experiences with attachment figures. The attachment literature globally shows that the qualities of IWMs are neither gender specific nor cultural specific. Procedures to evaluate IWMs in adulthood have been well established, based on narrative accounts of childhood experiences. Narrative procedures at earlier ages (e.g., in the preschool years) have been proposed, such as Bretherton's Attachment Story Completion Task (ASCT), to evaluate attachment representations. More than 500 ASCT narratives of preschoolers, coming from five different countries, have been collected, in the perspective of examining possible interactions between gender and culture regarding attachment representations. A specific Q-Sort coding procedure (CCH) has been used to evaluate several dimensions of the narratives. Girls' narratives appeared as systematically more secure than those of same-age boys, whatever their culture. The magnitude of gender differences, however, varied between countries. Taylor's model of gender-specific responses to stress and Harwood's and Posada's hypothesis on inter-cultural differences regarding caregiving are evoked to understand the differences across gender and countries.

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Background: Studies have found higher levels of insecure attachment in individuals with schizophrenia. Attachment theory provides a framework necessary for conceptualizing the development of interpersonal functioning. Some aspects of the attachment of the believer to his/her spiritual figure are similar to those between the child and his/her parents. The correspondence hypothesis suggests that early child-parent interactions correspond to a person's relation to a spiritual figure. The compensation hypothesis suggests that an insecure attachment history would lead to a strong religiousness/spirituality as a compensation for the lack of felt security. The aim of this study is to explore attachment models in psychosis vs. healthy controls, the relationships between attachment and psychopathology and the attachment processes related to spiritual figures. Methods: Attachment models were measured in 30 patients with psychosis and 18 controls with the AAI (Adult Attachment interview) in relationship with psychopathology. Beliefs and practices related to a spiritual figure were investigated by qualitative and quantitative analyses. Results: Patients with psychosis showed a high prevalence of insecure avoidant attachment. Spiritual entities functioned like attachment figures in two thirds of cases. Interviews revealed the transformation of internal working models within relation to a spiritual figure: a compensation process was found in 7 of the 32 subjects who showed a significant attachment to a spiritual figure. Conclusions: Attachment theory allows us to highlight one of the underlying dimensions of spiritual coping in patients with psychosis.

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A acirrada competição econômica e a profunda revolução tecnológica impõem às organizações contemporâneas mudanças significativas na organização da produção. Nesse contexto configuram-se algumas contradições. Por um lado exalta-se a importância da participação do trabalhador como fator decisivo na construção de vantagens competitivas, uma vez que o sucesso da organização tem como um dos principais requisitos a implantação de modelos de funcionamento que contemplem atividades geradoras de conhecimento novo, disseminem-no amplamente a toda organização e, rapidamente, incorporem-no a novas tecnologias e produtos. Por outro lado, também na busca de maiores graus de competitividade, práticas de flexibilização das relações de trabalho vêm sendo adotadas como forma de diminuição dos custos de produção, através da redução das formas de proteção da relação de trabalho. No Brasil, a ação flexibilizante já vem ocorrendo desde 1965 e encontra-se hoje em tramitação no Congresso Nacional o Projeto de Lei 5483/2001 que, alterando o art. 618 da Consolidação das Leis do Trabalho, pretende a prevalência do negociado sobre o legislado. Neste sentido, o objetivo da pesquisa é verificar os efeitos da flexibilização das relações de trabalho na qualidade de vida no trabalho, no que se refere, especificamente, à gestão do conhecimento e às necessidades sociais do trabalhador quanto aos seus benefícios diretos e espontâneos. Configura-se como um estudo de campo com foco nas organizações, a partir dos representantes da área de gestão de pessoas e nos trabalhadores das indústrias, com mais de quinhentos funcionários, instaladas na Região Metropolitana de Curitiba. O método utilizado para tratamento dos dados possibilita mensuração de variáveis qualitativas e o estabelecimento da comparabilidade entre os trabalhadores sujeitos às práticas de flexibilização e os demais trabalhadores. Os dados coletados por meio de questionários revelaram que a flexibilização das relações de trabalho faz parte integrante do novo perfil das organizações e que há hoje uma tendência de implemento com a abertura legal. Os efeitos causados por essa ação sobre a qualidade de vida no trabalho revelam-se predatórios, na medida em que os trabalhadores com contratos de trabalho flexibilizados encontram-se em posição de desvantagem no acesso à aprendizagem dentro das organizações e, também, na satisfação de suas necessidades sociais. Na análise comparativa entre as duas categorias de trabalhadores, foi possível verificar diferenças significativas no que diz respeito aos indicadores de participação no processo produtivo através da freqüência média de soluções apresentadas e incorporadas, da participação nos processos de aquisição do conhecimento, no acesso a benefícios diretos e espontâneos e na satisfação com o ambiente de trabalho. Essas constatações permitem concluir que as organizações, quando na busca de maior competitividade, incorrem em equívocos à medida em que desconsideram a qualidade de vida no trabalho, especificamente no que diz respeito à gestão do conhecimento e à satisfação das necessidades sociais como fatores maximizantes do desenvolvimento econômico e de incremento da produção.

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This study examined the meaning-making and psychosocial processes of five female legacy students at Bucknell University, each of whom having had at least one parent graduate from the institution. With a research philosophy, design, and methodology rooted in qualitative inquiry and phenomenology, inductive data analysis led to three primary categories that underscored legacy identity development. The first, Paradox of Influence and Identity, revealed through six themes nuanced experiences of separation-individuation. Second, Teaching and Learning, comprised of five themes, illuminated the impact of family — and of Bucknell parent alumni in particular — on their children’s internal working models. Lastly, Bucknell — the Environmental Contextand the five themes grouped therein highlighted the contributions of University community members, and of the campus culture and climate itself, to the co-construction of psychosocial formation. A tentative outline of grounded theory was offered, which explored categorical relationships; Paradox of Influence and Identity emerged as thedominant phenomenon, informing and being reinforced by the data of Teaching and Learning and Bucknell — the Environmental Context. Provisional intervention strategies for student affairs practice, in the contexts of academics, residential life, and career development, were discussed. Further, triangulated research is needed to substantiate and evolve the findings and theoretical model of this thesis.

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Suppose that having established a marginal total effect of a point exposure on a time-to-event outcome, an investigator wishes to decompose this effect into its direct and indirect pathways, also know as natural direct and indirect effects, mediated by a variable known to occur after the exposure and prior to the outcome. This paper proposes a theory of estimation of natural direct and indirect effects in two important semiparametric models for a failure time outcome. The underlying survival model for the marginal total effect and thus for the direct and indirect effects, can either be a marginal structural Cox proportional hazards model, or a marginal structural additive hazards model. The proposed theory delivers new estimators for mediation analysis in each of these models, with appealing robustness properties. Specifically, in order to guarantee ignorability with respect to the exposure and mediator variables, the approach, which is multiply robust, allows the investigator to use several flexible working models to adjust for confounding by a large number of pre-exposure variables. Multiple robustness is appealing because it only requires a subset of working models to be correct for consistency; furthermore, the analyst need not know which subset of working models is in fact correct to report valid inferences. Finally, a novel semiparametric sensitivity analysis technique is developed for each of these models, to assess the impact on inference, of a violation of the assumption of ignorability of the mediator.

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ModelDB's mission is to link computational models and publications, supporting the field of computational neuroscience (CNS) by making model source code readily available. It is continually expanding, and currently contains source code for more than 300 models that cover more than 41 topics. Investigators, educators, and students can use it to obtain working models that reproduce published results and can be modified to test for new domains of applicability. Users can browse ModelDB to survey the field of computational neuroscience, or pursue more focused explorations of specific topics. Here we describe tutorials and initial experiences with ModelDB as an interactive educational tool.