57 resultados para Cognition in old age
Resumo:
Apolipoprotein L1 in plasma is associated with high- density lipoprotein. Novel APOL1 polymorphisms are investigated along with the association of two common haplotypes (Lys166Glu, Ile244Met, Lys271Arg) with circulating lipid and glucose levels. Although the amino acid substitutions occur in the amphipathic alpha helices region involved in lipid binding, these substitutions were found not to independently account for variability in circulating lipid and glucose levels in 149 middle age males.
Resumo:
Individuals with Williams syndrome typically show relatively poor visuospatial abilities in comparison to stronger verbal skills. However, individuals' level of performance is not consistent across all visuospatial tasks. The studies assessing visuospatial functioning in Williams syndrome are critically reviewed, to provide a clear pattern of the relative difficulty of these tasks. This prompts a possible explanation of the variability in performance seen, which focuses on the processing demands of some of these tasks. Individuals with Williams syndrome show an atypical processing style on tests of construction, which does not affect tests of perception.
Resumo:
The populations of many species are structured such that mating is not random and occurs between members of local patches. When patches are founded by a single female and all matings occur between siblings, brothers may compete with each other for matings with their sisters. This local mate competition (LMC) selects for a female-biased sex ratio, especially in species where females have control over offspring sex, as in the parasitic Hymenoptera. Two factors are predicted to decrease the degree of female bias: (1) an increase in the number of foundress females in the patch and (2) an increase in the fraction of individuals mating after dispersal from the natal patch. Pollinating fig wasps are well known as classic examples of species where all matings occur in the local patch. We studied non-pollinating fig wasps, which are more diverse than the pollinating fig wasps and also provide natural experimental groups of species with different male morphologies that are linked to different mating structures. In this group of wasps, species with wingless males mate in the local patch (i.e. the fig fruit) while winged male species mate after dispersal. Species with both kinds of male have a mixture of local and non-local mating. Data from 44 species show that sex ratios (defined as the proportion of males) are in accordance with theoretical predictions: wingless male species < wing-dimorphic male species < winged male species. These results are also supported by a formal comparative analysis that controls for phylogeny. The foundress number is difficult to estimate directly for non-pollinating fig wasps but a robust indirect method leads to the prediction that foundress number, and hence sex ratio, should increase with the proportion of patches occupied in a crop. This result is supported strongly across 19 species with wingless males, but not across 8 species with winged males. The mean sex ratios for species with winged males are not significantly different from 0.5, and the absence of the correlation observed across species with wingless males may reflect weak selection to adjust the sex ratio in species whose population mating structure tends not to be subdivided. The same relationship is also predicted to occur within species if individual females adjust their sex ratios facultatively. This final prediction was not supported by data from a wingless male species, a male wing-dimorphic species or a winged male species.
Resumo:
Around the time of Clausewitz’s writing, a new element was introduced into partisan warfare: ideology. Previously, under the ancien régime, partisans were what today we would call special forces, light infantry or cavalry, almost always mercenaries, carrying out special operations, while the main action in war took place between regular armies. Clausewitz lectured his students on such ‘small wars’. In the American War of Independence and the resistance against Napoleon and his allies, operations carried out by such partisans merged with counter-revolutionary, nationalist insurgencies, but these Clausewitz analysed in a distinct category, ‘people's war’. Small wars, people's war, etc. should thus not be thought of as monopoly of either the political Right or the Left.
Resumo:
Future research is required into the prevalence of loneliness, anxiety and depression in adults with visual impairment, and to evaluate the effectiveness of interventions for improving psychosocial well-being such as counselling, peer support and employment programmes.