Although each statistical unit on which measurements are taken is unique typically there is not enough information available to account totally for its uniqueness. Therefore heterogeneity among units has to be limited by structural assumptions. One classical approach is to use random effects models, which assume that heterogeneity can be described by distributional assumptions. However, inferen...

the main purpose of this paper has been to discuss the effects of psychological stress and other environmental factors on incidence of diseases. we were specifically concerned with stress that increased susceptibility of uninfected hosts when exposed to infection. if such stresses also reduced resources, fecundity and/or survivorship, there was a reduction in the host carrying capacity. in addi...

Meta-analysis is a standard statistical method used to combine the conclusions of individual studies that are related and the results of single study alone can not answered to deal with issues. The data are summarized by one or more outcome measure estimates along with their standard errors. The multivariate model and the variations between studies are not considered in most articles. Here we d...

This paper sheds some light on the problems associated with random effects gravity approaches. Arguments for the superiority of a fixed effects model are given both along intuitive and econometric lines based on a Hausman test.  2000 Elsevier Science S.A. All rights reserved.

This paper uses data drawn from the English Football League to model separate hazard rates for club managers for the 2001/2, 2002/3 and 2003/4 seasons. On average over the three seasons, approximately one-third of managers involuntarily exited employment status with their club. We model the hazard using a standard logistic model exploiting information on the spell at risk rather than the indivi...

nowadays, environmental problems such as air pollution are the most effective factors in metropolitans. so that, the most important effect of environmental factors such as air pollution has been on prices of residential houses. so, investigation the effects of different factors on residential houses shows that prices have special importance. this article has investigated an environmental approa...

This paper presents a dual-objective facility programming model for a green supply chain network. The main objectives of the presented model are minimizing overall expenditure and negative environmental impacts of the supply chain. This study contributes to the existing literature by incorporating uncertainty in customer demand, suppliers, production, and casting capacity. An industrial case st...

Background: Are dietary patterns, substantiated by biomarkers, associated with semen quality? Materials and Methods: In 161 men of subfertile couples undergoing in vitro fertilization treatment in a tertiary referral clinic in Rotterdam, the Netherlands, we assessed nutrient intakes and performed principal component factor analysis to identify dietary patterns. Total homocysteine (tHcy), folate...

despite several authors having studied the strategic approach to environmental orientation and,considering that environmental proactivity is emerging in business strategy, it still remains unclear which realactions influence a firm’s environmental orientation. an empirical analysis of a sample of 126 spanish companies shows that firms’ actions are explained as training, information and divulgat...