Perceptual-cognitive expertise of handball coaches in their young and middle adult years

There is little research investigating the maintenance of perceptual-cognitive expertise in general and even less comparing coaches of different ages. The aim of this study was to test for perceptual-cognitive differences between age groups, licence levels, and their interaction. This study investigated differences in skilled performance between young and middle-aged coaches of three different skill levels. Participants performed an accuracy-oriented pattern recall (mean distance in pixel) and a time-oriented flicker test (mean detection time in ms). There were some significant differences between age groups and between skill groups for both tests, but no interactions. For the pattern recall test, the effect sizes were larger for skill level differences, while for the flicker test effects were larger for ageing. These results suggest coaches are able to maintain accuracy skills better than reaction timed tasks. This is in line with findings on speeded performance in general populations, which show declines with age. Moreover, results also support findings on perceptual expertise in skills where accuracy was important.     

Active recovery of the finger flexors enhances intermittent handgrip performance in rock climbers

This study aimed to (1) evaluate the effect of hand shaking during recovery phases of intermittent testing on the time–force characteristics of performance and muscle oxygenation, and (2) assess inter-individual variability in the time to achieve the target force during intermittent testing in rock climbers. Twenty-two participants undertook three finger flexor endurance tests at 60% of their maximal voluntary contraction until failure. Performances of a sustained contraction and two intermittent contractions, each with different recovery strategies, were analysed by time–force parameters and near-infrared spectroscopy. Recovery with shaking of the forearm beside the body led to a significantly greater intermittent test time (↑ 22%, P?P?P?相似文献   

Alterations in autonomic cardiac modulation in response to normobaric hypoxia

Purpose: The present study aimed to determine if autonomic cardiac modulation was influenced by acute exposure to normobaric hypoxia. Method: Ten healthy male lowland dwellers completed five block-randomised single-blinded, crossed-over acute exposures to a normobaric hypoxic environment, each separated by 24 hours’ recovery (20.3%, 17.4%, 14.5%, 12.0% and 9.8% F_IO₂). Supine recordings were made of arterial oxygen saturation and electrocardiogram (ECG). RR intervals from the ECG trace were analysed for time (SDNN, lnrMSSD), frequency (lnVLF, lnLF, lnHF, lnTP, LFnu, and HFnu), and nonlinear (DFA-α1 and SampEn) heart rate variability components. Results: A significant reduction in arterial SaO₂ occurred with reduced F_IO₂, along with a rise in heart rate (Cohen’s d?=?1.16, 95% Confidence Interval [2.64–6.46]), significant at 9.8% F_IO₂. A decrease in autonomic cardiac modulation was also found as shown by a statistically significant (at 9.8% F_IO₂) decrease in lnTP (d?=?1.84 [1.74–1.94]), and SampEn (d?=?0.98 [0.83–1.12]) and an increase in DFA-α₁ (d?=?0.72 [0.60–0.84]) from normoxia at 9.8% F_IO₂. Conclusion: The decrease in variability indicated a reduction in autonomic cardiac modulation. There appears to be a threshold ～9.8% F_IO₂ (～6000?m equiv.), below which significant alterations in autonomic control occur.     

Will Obama's My Brother's Keeper and Similar Initiatives Have a Positive Impact on Low-Income Students?

Barack Obama's My Brother's Keeper is designed to narrow persistent gaps that boys and young men of color confront often and to help all young people achieve their potential in college and career. An important part of this initiative is comprehensive mentoring that supports students in schools and in communities. Because ethnic-minority students have extremely low graduation rates in high school and college, an essential question is addressed: Can My Brother's Keeper and similar initiatives with a mentoring component be effective in helping minority students to achieve success in elementary and secondary schools and in college?     

The relationship between individual instructional characteristics and the overall assessment of teaching effectiveness across different instructional contexts

There is an ongoing debate in the student evaluation of teaching literature about whether an overall rating or factorial dimensions of teaching effectiveness should be used in personnel decisions. Marsh and his colleagues have advocated the use of a weighted average approach to computing overall evaluations. A policy-capturing experiment was carried out where students in three different instructional contexts made overall evaluations of hypothetical instructors based on a manipulation of the teaching factors in Marsh's SEEQ. The results indicated (1) amount learned was consistently the most important factor affecting overall evaluations; (2) course difficulty was consistently the least important factor affecting overall evaluations; and (3) there was a strong similarity among the three groups in the relative importance of the various teaching factors in arriving at an overall evaluation. The implications of this research are discussed, as well as directions for future research.