Dynamic stability during running gait termination: Predictors for successful control of forward momentum in children and adults

Reported differences between children and adults with respect to COM horizontal and vertical position to maintain dynamic stability during running deceleration suggest that this relationship may not be as important in children. This study challenged the current dynamic stability paradigm by determining the features of whole body posture that predicted forward velocity and momentum of running gait termination in adults and children. Sixteen adults and 15 children ran as fast as possible and stopped at pre-determined location. Separate regression analyses determined whether COM posterior and vertical positions and functional limb length (distance between COM and stance foot) predicted velocity and momentum for adults and children. COM posterior position was the strongest predictor of forward velocity and momentum in both groups supporting the previously established relationship during slower tasks. COM vertical position also predicted momentum in children, not adults. Higher COM position in children was related to greater momentum; consistent with previously reported differences between children and adults in COM position across running deceleration. COM vertical position was related to momentum but not velocity in children suggesting that strategies used to terminate running may be driven by demands imposed not just by velocity, but also the mass being decelerated.     

Sex and age group differences in the associations between sleep duration and BMI from adolescence to young adulthood

Objective: We examine concurrent and longitudinal associations between sleep duration (SD) and body mass index (BMI) from adolescence to young adulthood, controlling for physical activity and internalising symptoms. Sex and age group differences (early adolescent group ages 12–15 years and late adolescent group ages 16–18 years) are examined.

Design: A randomly selected community-based sample of youth (N = 662; 48.3% males) were surveyed biannually from 2003 (T1) to 2014 (T6).

Results: We found sex and age group differences for the concurrent and longitudinal associations between SD and BMI. For males, shorter SD at baseline was concurrently related to higher BMI. For females, shorter SD at baseline was associated with longitudinal increases in BMI, for the late adolescent group only.

Conclusion: Findings show that the association between SD and BMI, previously shown in childhood, continues to be significant in adolescence and young adulthood. Developmentally appropriate and sex-specific strategies for motivating and supporting healthy sleep habits in adolescence that may help to prevent weight gain into young adulthood are discussed.     

Habituation to a stressor predicts adolescents' adiposity

Background and Objectives: Stress is associated with gains in adiposity. One factor that determines how much stress is experienced is how quickly an adolescent reduces responding (habituates) across repeated stressors. The purpose of this study was to determine the association of body mass index (BMI) percentile and the rate of habituation to a stressor. Design: Thirty-four adolescents completed anthropometric measures and a habituation protocol using a within study design. Methods: The habituation protocol measured the rate of decline in perceived stress and heart rate (HR) across four, two-minute serial subtraction trials. Results: Multivariate linear regression revealed the habituation rate of the HR predicted BMI percentile after adjusting for gender, socioeconomic status, and initial HR (β?=?17.2, p?Conclusions: Slower habituation to a laboratory stressor was associated with greater BMI percentiles in adolescents.     

The interactive effects of age,education, and BMI on cognitive functioning

We examined the moderating effects of age and cognitive reserve on the relationship between body mass index (BMI) and processing speed, executive function, and working memory based on the literature suggesting that obese individuals perform more poorly on measures of these abilities. Fifty-six healthy, dementia-free community-dwelling older (mean age 65.72 ± 7.40) and younger (mean age 21.10 ± 2.33) adults completed a neuropsychological battery and reported height and weight. Mixed effects models were used to evaluate the interactive effects of age, education (a proxy for cognitive reserve), and BMI on cognitive scores. Higher education was protective for executive deficits in younger, but not older adults. Age differences in executive functions were reduced at higher education levels but increased in individuals with higher BMI. Results suggest the inter-relationships between cognitive reserve – as measured by education – and BMI differ across age, and that obesity may accelerate the cognitive aging process.     

3D analysis of the body center of mass in rock climbing

The purpose of the present study was to search for common patterns and for differences in climbing strategies in a group of recreational climbers. Twelve participants were involved in the study. Each participant climbed a simple indoor route consisting of a 3m horizontal shift followed by a 3m ascent for five times. Climbers could choose their own style, their preferred speed and holds. Their motion was recorded through motion capture based on passive markers. Results suggested that two main climbing strategies were used: the first preferring agility over force and the second preferring force over agility. We also found that our best climbers tried to minimize power during all trials.     

The development of executive function in early childhood is inversely related to change in body mass index: Evidence for an energetic tradeoff?

A well‐established literature demonstrates executive function (EF) deficits in obese children and adults relative to healthy weight comparisons. EF deficits in obesity are associated with overeating and impulsive consumption of high calorie foods leading to excess weight gain and to problems with metabolic regulation and low‐grade inflammation that detrimentally affect the structure and function of prefrontal cortex. Here, we test a complementary explanation for the relation between EF and body mass index (BMI) grounded in the energy demand of the developing brain. Recent work shows that the brain accounts for a lifetime peak of 66% of resting metabolic rate in childhood and that developmental changes in brain energetics and normative changes in body weight gain are closely inversely related. This finding suggests a trade‐off in early childhood between energy used to support brain development versus energy used to support physical growth and fat deposition. To test this theorized energetic trade‐off, we analyzed data from a large longitudinal sample (N = 1,292) and found that change in EF from age 3 to 5 years, as a proxy for brain development in energetically costly prefrontal cortex, is inversely related to change in BMI from age 2 to 5 years. Greater linear decline in BMI predicted greater linear increase in EF. We interpret this finding as tentative support for a brain–body energetic trade‐off in early childhood with implications for lifetime obesity risk.     

肥胖男性血浆脂联素水平及影响因素

检测正常男性血浆脂联素水平,探讨其与各检测指标之间的相关性。选取正常男性96例,按体重指数（BMI）将上述两组分为2个亚组：肥胖（BMI≥25kg／m^2）组40例及体重正常（BMI〈25kg／m^2）组56例,测定空腹血浆脂联素浓度。肥胖组的血浆脂联素水平[（7．48±3．4）μg／m1]明显低于体重正常组[（10．57±4．73）μg／m1],差异有显著的统计学意义（P〈0．01）。相关分析显示血浆脂联素与体重指数（BMI）、腰围（WC）、血压（BP）、总胆固醇（TC）、血清胰岛素（FINs）、胰岛素抵抗指数（HOMA-IR）之间存在负相关,与高密度脂蛋白胆固醇（HDL-C）正相关。BMI、WC、HOMA-IR为影响血浆脂联素水平的独立因素。男性肥胖者血浆脂联素水平较体重正常者明显降低,血浆脂联素水平可能与肥胖及其相关疾病相关。     

The relative contribution of profile body shape and weight to judgements of women's physical attractiveness in Britain and Malaysia

Ninety-six Malaysian and British men rated for physical attractiveness a set of photographs of real women in profile, with known body mass index (BMI) and waist-to-hip ratio (WHR). Results showed that BMI accounted for the greater amount of variance in all settings. There were also significant differences in preferences for body weight, with low resource, low socioeconomic status (SES) raters preferring a significantly heavier partner than high resource, high SES raters. The disparity with previous findings using line drawings of women in profile was discussed in terms of the weaknesses of line-drawn stimuli.     

Preferences for female body size in Britain and the South Pacific

To assess current attitudes to body weight and shape in the South Pacific, a region characterised by relatively high levels of obesity and traditionally positive views of large bodies, 38 high socio-economic status (SES) adolescent males and 38 low SES adolescent males in Independent Samoa were asked to rate a set of images of real women for physical attractiveness. Participants in both SES settings preferred women with a slender figure, as did a comparison group in Britain, suggesting that the traditional veneration of large bodies is no longer apparent in Samoa. However, the results also showed that low SES adolescents were more likely to view overweight figures as attractive, which suggests that the veneration of slim figures may be associated with increasing SES. Implications of this finding are discussed in conclusion.     

“泗县甲肝疫苗事件”的启示

安徽省泗县甲肝疫苗事件是一起罕见的群体性心因反应,造成了巨大的经济损失和不良的社会影响。通过分析这次事件的发生起因、进展过程和处理结果,我们认识到目前卫生技术人员和政府部门在应对突发性公共卫生事件上存在能力缺乏和经验不足,这给我们在认识事物、分析问题和科学决策上带来了深刻的启示。