5 resultados para Hierarchical regression model
em Repositório Científico do Instituto Politécnico de Lisboa - Portugal
Resumo:
Interest rate risk is one of the major financial risks faced by banks due to the very nature of the banking business. The most common approach in the literature has been to estimate the impact of interest rate risk on banks using a simple linear regression model. However, the relationship between interest rate changes and bank stock returns does not need to be exclusively linear. This article provides a comprehensive analysis of the interest rate exposure of the Spanish banking industry employing both parametric and non parametric estimation methods. Its main contribution is to use, for the first time in the context of banks’ interest rate risk, a nonparametric regression technique that avoids the assumption of a specific functional form. One the one hand, it is found that the Spanish banking sector exhibits a remarkable degree of interest rate exposure, although the impact of interest rate changes on bank stock returns has significantly declined following the introduction of the euro. Further, a pattern of positive exposure emerges during the post-euro period. On the other hand, the results corresponding to the nonparametric model support the expansion of the conventional linear model in an attempt to gain a greater insight into the actual degree of exposure.
Resumo:
The aim of this work is to study the risk of obesity posed by two genetic factors: haptoglobin phenotype and acid phosphatase phenotype, one enzymatic activity: acid phosphatase activity (ACP1), age and gender. Haptoglobin (Hp) is a protein of the immune system, and three phenotypes of Hp are found in humans: Hp1-1, Hp2-1, and Hp2-2. This protein is associated with a susceptibility to common pathological conditions, such as obesity. ACP1 is an intracellular enzyme The phenotypes of ACP1 (AA, AB, AC, BB, BC, CC) are also considered. We took a sample of 127 subjects with complete data from 714 registers. Since we intend to identify risk factors for obesity, an ordinal regression model is adjusted, using the Body Mass Index, BMI, to define weight categories. Haptoglobin phenotype, enzymatic activity of ACP1, acid phosphatase phenotype, age and gender are considered as regressor variables. We found three factors associated with an increased risk of obesity: phenotype Hp2-1 of haptoglobin (estimated odds ratio OR 11.54), phenotype AA of acid phosphatase (OR 33.788) and age (OR 1.39). The interaction between phenotype Hp2-1 and phenotype AC is associated with a decreased risk of obesity (OR 0.032); The interaction between phenotype AA and ACP1 activity is associated with a decreased risk of obesity (OR 0.954).
Resumo:
Background: The effect of the intake of polynsaturated long chain fatty acids (LCPUFAs) during pregnancy on fetal body composition has been assessed by studies using mostly neonatal anthropometry. Their results have been inconsistent, probably because neonatal anthropometry has several validity limitations. Air displacement plethismography (ADP) is a recently validated non-invasive method for assessing body composition in neonates. Objective: To determine the effect of the intake of LCPUFAs during pregnancy on the body composition of term neonates, measured by ADP. Methods: Cross-sectional study of a convenience sample of healthy full-term neonates and their mothers. The diet during pregnancy was assessed using a validated semi-quantitative food frequency questionnaire; Food Processor Plus® was used to convert food intake into nutritional values. Body composition was estimated by anthropometry and measured by ADP using Pea Pod™ Life Measurements Inc (fat mass - FM, fat-free mass and %FM) within the first 72h after birth. Univariate and multivariate analysis (linear regression model) were performed. Results: 54 mother-neonate pairs were included. Multivariate analysis adjusted to the maternal body mass index shows positive association between LCPUFAs intake and neonatal mid-arm circumference (= 0,610, p = 0,019) and negative association between n-6:n-3 ratio intake and neonatal %FM (= -2,744, p=0,066). Conclusion: To the best of our knowledge, this is the first study on this subject using ADP and showing a negative association between LCPUFAs n-6:n-3 ratio intake in pregnancy and neonatal %FM. This preliminary finding requires confirmation increasing the study power with a greater sample and performing interventional studies.
Resumo:
A epilepsia é uma das patologias neurológicas mais comuns em todo o mundo, com repercussões importantes na Qualidade de Vida (QDV) dos indivíduos. Deste modo, o objetivo do tratamento ultrapassa a remissão total das crises epiléticas, dado que também prioriza a QDV do indivíduo com epilepsia. A QDV tem vindo a ser associada a alguns fatores modificáveis, importantes para a sua promoção. Assim, pretende-se com o presente estudo identificar se a Adesão à Terapêutica, as Estratégias de Coping e a Espiritualidade são preditores da QDV de indivíduos com epilepsia. O SF-36 v1.0, a Medida de Adesão aos Tratamentos, o COPE-R e a Escala de Avaliação de Espiritualidade em Contextos de Saúde foram administrados a 94 indivíduos com diagnóstico de epilepsia entre quatro e 49 anos. A relação entre as variáveis foi analisada através do modelo de regressão linear múltipla. Os resultados revelam que a Adesão à Terapêutica, a Esperança/Otimismo predizem positivamente a QDV. Já as estratégias de Coping Desinvestimento Comportamental, Expressão de Sentimentos e Religião predizem-na negativamente. Estes resultados são importantes para os profissionais de saúde, na medida em que a identificação de preditores modificáveis da QDV sugere pistas para intervenções que promovam a QDV de indivíduos com epilepsia.
Resumo:
Mestrado em Contabilidade e Análise Financeira