Effects of exercise training with weighted vests on bone turnover and isokinetic strength in postmenopausal women

The effects of 12 wk of exercise training using weighted vests on bone turnover and isokinetic strength were evaluated in postmenopausal women randomly assigned as exercisers (EX; n = 9) or controls (CON; n = 7). Training included 3 multimodal exercise sessions per wk wearing weighted vests. The vest load was progressively increased each wk to a maximum of 15% of body weight. Bone turnover was determined from resting levels of serum osteocalcin and NTx. Knee and ankle strength were measured at 60 degrees/s and 180 degrees/s using an isokinetic dynamometer. After 12 wk, NTx decreased by 14.5% (P 相似文献   

Regression spline bivariate probit models: A practical approach to testing for exogeneity

Bivariate probit models can deal with a problem usually known as endogeneity. This issue is likely to arise in observational studies when confounders are unobserved. We are concerned with testing the hypothesis of exogeneity (or absence of endogeneity) when using regression spline recursive and sample selection bivariate probit models. Likelihood ratio and gradient tests are discussed in this context and their empirical properties investigated and compared with those of the Lagrange multiplier and Wald tests through a Monte Carlo study. The tests are illustrated using two datasets in which the hypothesis of exogeneity needs to be tested.     

American College Health Association

Abstract

Objective: The purpose of this cross-sectional investigation was to examine (1) gender differences in osteoporosis-related knowledge and beliefs and (2) if these beliefs could predict vigorous physical activity behavior in university students. Participants: Male (n = 176) and female (n = 351) university students participated in the study. Methods: Participants completed self-report measures of osteoporosis knowledge and health beliefs and vigorous physical activity. Results: Regardless of gender, osteoporosis knowledge was relatively poor. Women reported higher knowledge, perceived susceptibility, perceived severity, and calcium barriers, and lower exercise self-efficacy than men. Regression analyses showed that for women, perceived susceptibility, health motivation, and exercise self-efficacy predicted vigorous physical activity, whereas for men, exercise barriers was the only predictor. Conclusions: Gender differences in osteoporosis health beliefs appear to be greater in older adults than college-aged students. Interventions designed to increase vigorous physical activity may want to target different beliefs for men and women.     

Conceptualizing Puberty as a Window of Opportunity for Impacting Health and Well‐Being Across the Life Span

We promote the perspective that puberty, a separate biological process embedded in adolescence, is a “window of opportunity” for understanding and impacting health and development. First, we include a brief overview of pubertal change. Second, we propose a critical role for puberty in shaping life span health due to its connections with early life precursors, health issues and risks emerging during puberty, and health in young adulthood and beyond. Next, we discuss the importance of puberty measures in developmental research and suggest ways to make the science of puberty an important standalone research entity, as well as an essential component of studies conducted during adolescence. Finally, we discuss measurement issues, novel theoretical models of puberty, and the necessity of adopting an interdisciplinary perspective in research on puberty and in adolescence more broadly.     

Students’ views on thesis supervision in international master’s degree programmes in Finnish universities

This paper employs an intercultural perspective to examine students’ views on master’s thesis supervision and the roles and responsibilities of supervisors and students. The 302 respondents who answered the online questionnaire were enrolled in international master’s degree programmes in four Finnish universities. The study revealed asymmetric views by students regarding the division of responsibilities between themselves and their supervisors. It was found that very few students and supervisors discuss the differences in study cultures between Finland and students’ countries of origin, their cultural backgrounds or the aspects of Finnish society that students do not understand. The research suggests that supervisors and students need to conduct early discussions on supervision and culture.     

Assessing the stability of classification trees using Florida birth data

Using 1998 and 1999 singleton birth data of the State of Florida, we study the stability of classification trees. Tree stability depends on both the learning algorithm and the specific data set. In this study, test samples are used in statistical learning to evaluate both stability and predictive performance. We also use the resampling technique bootstrap, which can be regarded as data self-perturbation, to evaluate the sensitivity of the modeling algorithm with respect to the specific data set. We demonstrate that the selection of the cost function plays an important role in stability. In particular, classifiers with equal misclassification costs and equal priors are less stable compared to those with unequal misclassification costs and equal priors.