We show that, in the presence of uncontrolled environmental confounding, joint tests for the presence of a main genetic effect and gene-environment interaction will be biased if the genetic and environmental factors are correlated, even if there is no effect of either the genetic factor or the environmental factor on the disease. When environmental confounding is ignored, such tests will in fac...

This review article aims to anatomize sources of the healthy worker effect (HWE) and to summarize advantages and limitations of several approaches frequently proposed to eliminate the HWE. Although the HWE is frequently addressed in the context of selection bias, our review suggests that the selection of occupational cohorts with advantageous health status would preferably be addressed as a sou...

Several authors within psychology, neuroscience and philosophy take for granted that standard empirical research techniques are applicable when studying consciousness. In this article, it is discussed whether one of the key methods in cognitive neuroscience – the contrastive analysis – suffers from any serious confounding when applied to the field of consciousness studies; that is to say, if th...

When brain injury is refractory to aggressive management and is considered nonsurvivable, with loss of consciousness and brain stem reflexes, a brain death protocol may be initiated to determine death according to neurological criteria. Clinical evaluation typically entails 2 consecutive formal neurological examinations to document total loss of consciousness and absence of brain stem reflexes ...

The aim of aetiologic studies in epidemiology is to investigate whether factors are causally related to diseases and therefore become a potential target for therapeutic interventions. Mendelian randomization enables estimation of causal relationships in observational studies using genetic variants as instrumental variables. An instrumental variable is a variable that can be considered to mimic ...

background: autism spectrum disorder (asd) is a neurological disorder typically appearing before the age of three . the exact cause of autism remains uncertain, and several factors may be involved in its onset: genetic factors and possible environmental factors. the aim of this study was to assess the correlates of autism in the lebanese population. methods: we investigated the association of a...