33 resultados para Thermal Evolution
Resumo:
This paper reports an analysis of the evolution of income related health inequalities in Spain over the period 1987-2001. We use recently developed methods in order to cardinalise and model self assessed health within a regression framework, decompose the sources of inequality and explain the observed differences between 1987 (one year after the 1986 General Health Act was approved) and 2001 (the latest available representative data on health for the Spanish population). The results show that the period has witnessed a reduction in income related health inequality. The driver of such reduction has been the weakening of the income health gradient, which lends support to the hypothesis that the important health policy reforms implemented over the period have been successful in the objective of reducing socio-economic inequalities in health. Our results also suggest that actions aimed at improving the health of those with low levels of education and of those who are not actively participating in the labor market would lead to further reductions in income related health inequality.
Resumo:
Cofoundresses of the desert fungus garden ant Acromyrmex versicolorexhibit a forager specialist who subsumes all foraging risk priorto first worker eclosion (Rissing et al. 1989). In an experimentdesigned to mimic a "cheater" who refuses foraging assignment whenher lot, cofoundresses delayed/failed to replace their forager,often leading to demise of their garden (Rissing et al. 1996). Thecheater on task assignment is harmed, but so too is the punisher,as all will die without a healthy garden. In this paper we studythrough simulation the cofoundress interaction with haploid, asexualgenotypes which either replace a cheater or not (punishment), underboth foundress viscosity (likely for A. versicolor) and randomassortment. We find replacement superior to punishment only whenthere is no foraging risk and cheating is not costly to groupsurvival. Generally, punishment is evolutionarily superior,especially as forager risk increases, under both forms of dispersal.