910 resultados para PHYSICAL-FITNESS
Resumo:
Background: The aim of this study was to examine minor physical anomalies and quantitative measures of the head and face in patients with psychosis vs healthy controls. Methods: Based on a comprehensive prevalence study of psychosis, we recruited 310 individuals with psychosis and 303 controls. From this sample, we matched 180 case-control pairs for age and sex. Individual minor physical anomalies and quantitative measures related to head size and facial height and depth were compared within the matched pairs. Based on all subjects, we examined the specificity of the findings by comparing craniofacial summary scores in patients with nonaffective or affective psychosis and controls. Results: The odds of having a psychotic disorder were increased in those with wider skull bases (odds ratio [OR], 1.40; 95% confidence interval [CI], 1.02-1.17), smaller lower-facial heights (glabella to subnasal) (OR, 0.57; 95% CI, 0.44-0.75), protruding ears (OR, 1.72; 95% CI, 1.05-2.82), and shorter (OR, 2.29; 95% CI, 1.37-3.82) and wider (OR, 2.28; 95% CI, 1.43-3.65) palates. Compared with controls, those with psychotic disorder had skulls that were more brachycephalic. These differences were found to distinguish patients with nonaffective and affective psychoses from controls. Conclusions: Several of the features that differentiate patients from controls relate to the development of the neuro-basicranial complex and the adjacent temporal and frontal lobes. Future research should examine both the temporal lobe and the middle cranial fossa to reconcile our anthropomorphic findings and the literature showing smaller temporal lobes in patients with schizophrenia. Closer attention to the skull base may provide clues to the nature and timing of altered brain development in patients with psychosis.
Resumo:
The effects of wing shape, wing size, and fluctuating asymmetry in these measures oil the field fitness of T. nr. brassicae and T. pretiosum were investigated. Trichogramma wasps mass-reared on eggs of the factitious host Sitotroga cerealella were released in tomato paddocks and those females ovipositing on Helicoverpo spp. eggs were recaptured. Comparisons of the recaptured group with a sample from the release population were used to assess fitness. Wing data were obtained by positioning landmarks on mounted forewings. Size was then measured as the centroid size computed from landmark distances, while Procrustes analysis followed by principal component analysis was used to assess wing shape. Similar findings were obtained for both Trichogramma species: fitness of wasps was strongly related to wing size and some shape dimensions, but not to the asymmetries of these measures. Wasps which performed well in the field had larger wings and a different wing shape compared to wasps from the mass reared population. Both size and the shape dimensions were linearly associated with fitness although there was also some evidence for non-linear selection on shape. The results suggest that wing shape and wing size are reliable predictors of field fitness for these Trichogramma wasps.
Resumo:
The sexual ornamentation used by male guppies to attract females comprises many components, each of which varies considerably among males. Although natural and sexual selection have been shown to contribute to divergence among populations in male sexual ornaments, the role of sexual selection in maintaining polymorphism within populations is less clear. We used both parametric quadratic regression and nonparametric projection pursuit regression techniques to reveal the major axes of non-linear sexual selection on male ornaments. We visualized the fitness surfaces defined by these axes using thin-plate splines to allow a direct comparison of the two methodologies. Identification of the major axes of selection and their visualization was critical in determining the form and strength of nonlinear selection. Both types of analysis revealed fitness surfaces comprising three peaks, suggesting that there is more than one way to make an attractive guppy. Disruptive selection may be an important process underlying the presence of multiple sexual ornaments and may contribute to the maintenance of the high levels of polymorphism in male sexual ornaments found in guppy populations.
Resumo:
Background: Physical activity (PA) patterns are likely to change in young adulthood in line with changes in lifestyle that occur in the transition from adolescence to adulthood. The aim of this study was to ascertain whether key life events experienced by young women in their early twenties are associated with increasing levels of inactivity. Methods: This was a 4-year follow-up of 7281 participants (aged 18 to 23 years at baseline) in the Australian Longitudinal Study of Women's Health, with self-reported measures of PA, life events, body mass index (BMI), and sociodemographic variables. Results: The cross-sectional data indicated no change in PA between baseline (57% active) and follow-up (56% active). However, for almost 40% of the sample, PA category changed between baseline and follow-up, with approximately 20% of the women changing from being active to inactive, and another 20% changing from being inactive to active. After adjustment for age, other sociodemographic variables, BMI, and PA at baseline, women who reported getting married, having a first or subsequent child, or beginning paid work were more likely to be inactive at follow-up than those who did not report these events. Conclusions: The results suggest that life events such as getting married, having children, and starting work are associated with decreased levels of PA in young adult women. Strategies are needed to promote maintenance of activity at the time when most women experience these key life-stage transitions.
Resumo:
The epidemic that is osteoporosis has led to an increasing interest in bone mineral, and the factors that influence the levels of bone mineral, in recent years. While it is unrealistic to try and turn back the clock, a return to an increased level of physical activity may be an important consideration in terms of skeletal health. Peak bone mass is largely determined by heredity, but lifestyle and dietary patterns also influence the level of bone mineral accrued during the growing years. In this review, we summarize the evidence that vigorous weight-bearing physical activity and adequate calcium intake represent the best possibility for enhancing the attainment of an optimal level of bone mineral, within genetic limits.
Resumo:
Increased professionalism in rugby has elicited rapid changes in the fitness profile of elite players. Recent research, focusing on the physiological and anthropometrical characteristics of rugby players, and the demands of competition are reviewed. The paucity of research on contemporary elite rugby players is highlighted, along with the need for standardised testing protocols. Recent data reinforce the pronounced differences in the anthropometric and physical characteristics of the forwards and backs. Forwards are typically heavier, taller, and have a greater proportion of body fat than backs. These characteristics are changing, with forwards developing greater total mass and higher muscularity. The forwards demonstrate superior absolute aerobic and anaerobic power, and Muscular strength. Results favour the backs when body mass is taken into account. The scaling of results to body mass can be problematic and future investigations should present results using power function ratios. Recommended tests for elite players include body mass and skinfolds, vertical jump, speed, and the multi-stage shuttle run. Repeat sprint testing is a possible avenue for more specific evaluation of players. During competition, high-intensity efforts are often followed by periods of incomplete recovery. The total work over the duration of a game is lower in the backs compared with the forwards; forwards spend greater time in physical contact with the opposition while the backs spend more time in free running, allowing them to cover greater distances. The intense efforts undertaken by rugby players place considerable stress on anaerobic energy sources, while the aerobic system provides energy during repeated efforts and for recovery. Training should focus on repeated brief high-intensity efforts with short rest intervals to condition players to the demands of the game. Training for the forwards should emphasise the higher work rates of the game, while extended rest periods can be provided to the backs. Players should not only be prepared for the demands of competition, but also the stress of travel and extreme environmental conditions. The greater professionalism of rugby union has increased scientific research in the sport; however, there is scope for significant refinement of investigations on the physiological demands of the game, and sports-specific testing procedures.
Resumo:
Objective: To explore relationships between physical activity and mental health cross-sectionally and longitudinally in a large cohort of older Australian women. Method: Women in their 70s participating in the Australian Longitudinal Study on Women's Health responded in 1996 (aged 70-75) and in 1999 (aged 73-78). Cross-sectional data were analyzed for 10,063 women and longitudinal data for 6472. Self-reports were used to categorize women into four categories of physical activity at each time point as well as to define four physical activity transition categories across the 3-year period. Outcome variables for the cross-sectional analyses were the mental health component score (MCS) and mental health subscales of the Medical Outcomes Study Short Form (SF-36). The longitudinal analyses focused on changes in these variables. Confounders included the physical health component scale (PCS) of the SF-36, marital status, body mass index (BMI) and life events. Adjustment for baseline scores was included for the longitudinal analyses. Results: Cross-sectionally, higher levels of physical activity were associated with higher scores on all dependent variables, both with and without adjustment for confounders. Longitudinally, the effects were weaker, but women who had made a transition from some physical activity to none generally showed more negative changes in emotional well-being than those who had always been sedentary, while those who maintained or adopted physical activity had better outcomes. Conclusion: Physical activity is associated with emotional well-being among a population cohort of older women both cross-sectionally and longitudinally, supporting the need for the promotion of appropriate physical activity in this age group. (C) 2003 Elsevier Science Inc. All rights reserved.