Search results for "Random effect"

Hierarchical log Gaussian Cox process for regeneration in uneven-aged forests

2021

We propose a hierarchical log Gaussian Cox process (LGCP) for point patterns, where a set of points x affects another set of points y but not vice versa. We use the model to investigate the effect of large trees to the locations of seedlings. In the model, every point in x has a parametric influence kernel or signal, which together form an influence field. Conditionally on the parameters, the influence field acts as a spatial covariate in the intensity of the model, and the intensity itself is a non-linear function of the parameters. Points outside the observation window may affect the influence field inside the window. We propose an edge correction to account for this missing data. The par…

Renewable energy growth and the financial performance of electric utilities: A panel data study

2017

Electric utilities are under pressure to increase clean energy production. Although the adoption of renewable energy can improve the utilities' environmental performance, a fundamental question is if it also pays in economic terms. Building on the natural-resource-based view of the firm, we answer this question using two data analysis methods. First, we carry out a regression analysis of panel data from 66 large electric utilities covering the period 2005–2014, applying both a fixed and random effects estimator. Subsequently, we use the Granger causality test to explore possible causality links. Our results show a negative correlation at the firm level between renewable energy increase and …

The dietary inflammatory index and human health: an umbrella review of meta-analyses of observational studies

2021

Numerous observational studies have investigated the role of the Dietary Inflammatory Index (DII®) in chronic disease risk. The aims of this umbrella review and integrated meta-analyses were to systematically synthesize the observational evidence reporting on the associations between the DII and health outcomes based on meta-analyses, and to assess the quality and strength of the evidence for each associated outcome. This umbrella review with integrated meta-analyses investigated the association between the DII and a range of health outcomes based on meta-analyses of observational data. A credibility assessment was conducted for each outcome using the following criteria: Statistical heterog…

Efficacy of Chondroitin Sulfate in Patients with Knee Osteoarthritis: A Comprehensive Meta-Analysis Exploring Inconsistencies in Randomized, Placebo-…

2019

Introduction There are some controversies about treatment modalities in osteoarthritis (OA), including chondroitin sulfate (CS). The objective of this study was to determine whether CS is effective at alleviating pain and improving function in patients with knee OA and to identify the factors that explain inconsistencies in clinical trial results. Methods We conducted a systematic review of randomized, placebo-controlled trials, searching the databases Medline, Cochrane central register for controlled trials and Scopus. Random effects meta-analysis was then performed, using tau2 and I2 statistics to assess heterogeneity. The pain and Lequesne index (LI) scores were expressed as standardized…

Association between night-time extubation and clinical outcomes in adult patients

2021

Background: Whether night-time extubation is associated with clinical outcomes is unclear. Objective: The aim of this systematic review and meta-analysis was to evaluate the association between night-time extubation and the reintubation rate, mortality, ICU and in-hospital LOS in adult patients, compared with daytime extubation. Design: A systematic review and meta-analysis. Data sources: PubMed, EMBASE, CINAHL and Web of Science from inception to 2 January 2021 (PROSPERO registration - CRD42020222812). Eligibility criteria: Randomised, quasi and cluster randomised, and nonrandomised studies describing associations between adult patients' outcomes and time of extubation (daytime/night-time)…

Determinantes de la estructura de vencimiento de la deuda en las empresas no cotizadas de los sectores industrial y de la construcción en Colombia de…

2017

Este artículo de reflexión explora, analiza y formula evidencias empíricas en torno a las variables determinantes del plazo del endeudamiento (corto plazo) de las empresas no cotizadas de los sectores industrial y de la construcción en Colombia para el periodo de 2008 a 2014. De acuerdo con el procesamiento de la información contable y financiera anual de las empresas de estos sectores que están reportadas en el Sistema de Información y Reporte Empresarial (Sirem) de la Superintendencia de Sociedades, se construye una base de datos con dos paneles desbalanceados para cada sector. Posteriormente, dicha información es modelada estocásticamente, estimándose las variables para cada sector por m…

Recurrences following treatment of proliferative verrucous leukoplakia: A systematic review and meta-analysis.

2021

Objective A systematic review and meta-analysis was made of the incidence of recurrences in patients with proliferative verrucous leukoplakia subjected to different types of treatment. Methods The study was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines. A literature search was made in the Medline (PubMed), EMBASE and Web of Science databases, together with a manual search, covering the period from 1985 to January 2020, with no language restrictions. Studies were included if they described treatments applied to at least 10 patients with the corresponding outcomes. Methodological quality was evaluated using Jadad sca…

Change-point estimation in piecewise constant regression models and extensions

2015

Heart rate variability and self-control—A meta-analysis

2015

Heart rate variability (HRV) has been suggested as a biological correlate of self-control. Whereas many studies found a relationship between HRV at rest and self-control, effect sizes vary substantially across studies in magnitude and direction. This meta-analysis evaluated the association between HRV at rest and self-control in laboratory tasks, with a particular focus on the identification of moderating factors (task characteristics, methodological aspects of HRV assessment, demographics). Overall, 24 articles with 26 studies and 132 effects (n=2317, mean age=22.44, range 18.4-57.8) were integrated (random effects model with robust variance estimation). We found a positive average effect …

Exploring Neighborhood Influences on Small-Area Variations in Intimate Partner Violence Risk: A Bayesian Random-Effects Modeling Approach

2014

This paper uses spatial data of cases of intimate partner violence against women (IPVAW) to examine neighborhood-level influences on small-area variations in IPVAW risk in a police district of the city of Valencia (Spain). To analyze area variations in IPVAW risk and its association with neighborhood-level explanatory variables we use a Bayesian spatial random-effects modeling approach, as well as disease mapping methods to represent risk probabilities in each area. Analyses show that IPVAW cases are more likely in areas of high immigrant concentration, high public disorder and crime, and high physical disorder. Results also show a spatial component indicating remaining variability attribut…