Search results for "random effects"
showing 10 items of 55 documents
Dynamics of female labour force participation in France
2013
International audience; This article formulates and estimates a structural intertemporal model of labour force participation. Relying on theoretical characterizations derived from an economic model of lifetime behaviour, we estimate a dynamic probit model with correlated random effects using longitudinal data to allow for a dynamic structure. The model is applied to a panel of married women drawn from the 1997–2002 French Labour Force surveys in order to represent their participation behaviour. It is estimated by maximum simulated likelihood. Our results show that women’s decisions to go out to work are characterized by significant state dependence, unobserved heterogeneity and negative ser…
A Bayesian Multilevel Random-Effects Model for Estimating Noise in Image Sensors
2020
Sensor noise sources cause differences in the signal recorded across pixels in a single image and across multiple images. This paper presents a Bayesian approach to decomposing and characterizing the sensor noise sources involved in imaging with digital cameras. A Bayesian probabilistic model based on the (theoretical) model for noise sources in image sensing is fitted to a set of a time-series of images with different reflectance and wavelengths under controlled lighting conditions. The image sensing model is a complex model, with several interacting components dependent on reflectance and wavelength. The properties of the Bayesian approach of defining conditional dependencies among parame…
Bayesian Analysis of Population Health Data
2021
The analysis of population-wide datasets can provide insight on the health status of large populations so that public health officials can make data-driven decisions. The analysis of such datasets often requires highly parameterized models with different types of fixed and random effects to account for risk factors, spatial and temporal variations, multilevel effects and other sources on uncertainty. To illustrate the potential of Bayesian hierarchical models, a dataset of about 500,000 inhabitants released by the Polish National Health Fund containing information about ischemic stroke incidence for a 2-year period is analyzed using different types of models. Spatial logistic regression and…
‘You play like a Woman!’ Effects of gender stereotype threat on Women's performance in physical and sport activities: A meta-analysis
2018
Abstract Objectives The purpose of this quantitative review was to provide an estimation of the effect of stereotype threat on women's performance in sport. Design This review employed a meta-analytic technique. Method a meta-analysis with random effects model was performed on 24 effects. Publication bias was tested through funnel plots and Egger's regression test. Results Findings show a symmetric distribution of effects, making it possible to conclude that no file-drawer problem affected the collected sample of effects. Aggregating the results of the reviewed studies, a medium effect of stereotype threat manipulation on women's sport performances emerged (d = 0.33). Collected studies were…
Even a low-dose of moderate-to-vigorous physical activity reduces mortality by 22% in adults aged ≥60 years: a systematic review and meta-analysis
2015
Type de document : revue de littérature; International audience; Background The health benefits of 150 min a week of moderate-to-vigorous-intensity physical activity (MVPA) in older adults, as currently recommended, are well established, but the suggested dose in older adults is often not reached.Objectives We aimed to determine whether a lower dose of MVPA was effective in reducing mortality, in participants older than 60 years.Methods The PubMed and Embase databases were searched from inception to February 2015. Only prospective cohorts were included. Risk ratios of death were established into four doses based on weekly Metabolic Equivalent of Task (MET)-minutes, defined as inactive (refe…
University student talent: the real driver for performance?
2017
Investigation about the university student performance, and its measurement, are very crucial issues for any policy maker. Since the economic crisis, jobs market requires even higher skills and competences. Literature offers a lot of papers about the university student quality and performance, in order to identify the main determinants of them. Often, results are very different, and they seems to hold just in a specific context. This paper aims to investigate the role of a latent variable that can take into account the student motivation, aptitude, and abilities, here conveniently called talent. A random effect Quantile Regression on a new measure of Italian student performance has been ado…
Survival time and differences between dementia with Lewy bodies and Alzheimer’s disease following diagnosis: a meta-analysis of longitudinal studies.
2019
Objective: To synthesize the evidence across longitudinal studies comparing survival in dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Methods: We conducted a systematic review and meta-analysis of studies comparing survival in clinically diagnosed DLB to AD. Longitudinal cohort studies were identified through a systematic search of major electronic databases from inception to May 2018. A random effects meta-analysis was performed to calculate survival time and relative risk of death. Results: Overall, 11 studies were identified including 22,952 patients with dementia: 2029 with DLB (mean diagnosis age 76.3; 47% female) compared with 20,923 with AD (mean diagnosis age 77.2; 6…
Random effects elliptically distributed in unbalanced linear models
2008
In linear mixed effects models, random effects are used for modelling the variance-covariance structure of the response variable. These models are based on the assumption that the random effects are normally distributed, but in literature alternative random effect distributions have been proposed and the consequences of misspecification are investigated. These studies consider only balanced designs. Aim of this paper is to study an unbalanced linear mixed model with random effects elliptically distributed.
Detection of genomic regions underlying milk production traits in Valle del Belice dairy sheep using regional heritability mapping
2021
The aim of this study was to identify genomic regions underlying milk production traits in the Valle del Belice dairy sheep using regional heritability mapping (RHM). Repeated measurements for milk yield (MY), fat percentage and yield (F% and FY) and protein percentage and yield (P% and PY), collected over a period of six years (2006-2012) on 481 Valle del Belice ewes, were used for the analysis. Animals were genotyped with the Illumina 50k SNP chip. Variance components, heritabilities, and repeatability within and across lactations were estimated, fitting parity, litter size, season of lambing, and fortnights in milk, as fixed; and additive genetic, permanent environment within and across …
Two-level resolution of relative risk of dengue disease in a hyperendemic city of Colombia.
2018
Risk maps of dengue disease offer to the public health officers a tool to model disease risk in space and time. We analyzed the geographical distribution of relative incidence risk of dengue disease in a high incidence city from Colombia, and its evolution in time during the period January 2009—December 2015, identifying regional effects at different levels of spatial aggregations. Cases of dengue disease were geocoded and spatially allocated to census sectors, and temporally aggregated by epidemiological periods. The census sectors are nested in administrative divisions defined as communes, configuring two levels of spatial aggregation for the dengue cases. Spatio-temporal models including…