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991.
Recent discussions of practices in higher education have tended toward muck-raking and self-styled exposure of cynical self-indulgence by faculty and administrators at the expense of students and their families, as usually occurs during periods of economic duress, rather than toward analytical studies designed to foster understanding This article looks briefly at some examples of this tendency and then offers an analytical approach to understanding faculty workloads and the ways of assessing and evaluating faculty work.  相似文献   
992.
The states of radiation of a single frequency and polarization propagating in free space are very conveniently represented by those of a quantum mechanical simple harmonic oscillator. This fact is exploited, together with the Ehrenfest theorem, to map the time evolution of the radiation to the dynamics of the oscillator. This enables a graphical comparison of the behaviour of classical and nonclassical states of radiation.  相似文献   
993.
To determine the validity and reliability of percent body fat estimates in 177 boys and 154 girls between 12–17 years of age, percent body fat was assessed once using dual-energy X-ray absorptiometry and twice using the sum of two skinfolds and three bioelectrical impedance analysis devices. The assessments were repeated on 79 participants on a second day. The agreement between the percent body fat estimates from the four prediction methods and dual-energy X-ray absorptiometry was evaluated using Bland–Altman analyses and a mixed linear model. All methods were reliable within and between days. The sum of two skinfolds (±6.8% body fat), OMRON (OMRON Healthcare Inc., Vernon Hills, Illinois, USA) bioelectrical impedance analysis (0 ± 7.3% body fat), and TANITA 521 (TANITA Corporation, Tokyo, Japan) bioelectrical impedance analysis (±7.6% body fat) had wide prediction intervals and are acceptable for use in large population-based studies. The TANITA 300A bioelectrical impedance analysis is not recommended for use in children and adolescents due to its wide prediction interval (±8.1% body fat) and large bias. A criterion method should be used when the accurate assessment of body composition of an individual is critical.  相似文献   
994.
Sport Management Review has been the sport management leader in publishing literature reviews and new theoretical frameworks. Despite these advances, scholars have not critically examined theory and its place in sport management scholarship. The purpose of this scholarly exchange is to address these issues, such that five scholars were invited to discuss how they conceptualize theory, the role of theory in the academia, and the process in which they engage when developing their own theories. This article provides an overview of the topic and introduces the articles.  相似文献   
995.
The aim of this study was to compare three competitive swimming starts (grab, rear-weighted track, and front-weighted track). The starts were compared in terms of time and instantaneous horizontal velocity, both at take-off from the block and at 5 m from the wall. Twenty US college female swimmers performed three trials of each of the three randomly ordered starts. Swimmers left the block significantly sooner using the front-weighted track start (0.80 s) than the other two starts (both 0.87 s; P < 0.001). In the rear-weighted track start, however, the athletes left the blocks with significantly higher horizontal velocity than in the grab or front-weighted track start (3.99 vs. 3.87 and 3.90 m/s, respectively; each P < 0.001). By 5 m, the front-weighted track start maintained its time advantage over the grab start (2.19 vs. 2.24 s; P = 0.008) but not the rear-weighted track start (2.19 vs. 2.21 s; P = 0.336). However, the rear-weighted track start had a significant advantage over the front-weighted track start in terms of instantaneous horizontal velocity at 5 m (2.25 vs. 2.18 m/s; P = 0.009). Therefore, the rear-weighted track start had a better combination of time and velocity than the front-weighted track start. There was also a trend for the rear-weighted track start to have higher velocity at 5 m than the grab start, although this did not reach statistical significance (2.25 vs. 2.20 m/s; P = 0.042). Overall, these results favour the rear-weighted track start for female swimmers even though most of the athletes had little or no prior experience with it. Additional research is needed to determine whether males would respond similarly to females in these three different swimming starts.  相似文献   
996.
Abstract

The purpose of this study was to develop a regression equation to predict maximal oxygen uptake (VO2max) based on nonexercise (N-EX) data. All participants (N= 100), ages 18–65 years, successfully completed a maximal graded exercise test (GXT) to assess VO2max (M= 39.96 mL·kg -1· min -1 , SD = 9.54). The N-EX data collected just before the maximal GXT included the participant's age; gender; body mass index (BMI); perceived functional ability (PFA) to walk, jog, or run given distances; and current physical activity (PA-R) level. Multiple linear regression generated the following N-EX prediction equation (R = .93, SEE = 3.45 mL·kg -1· min -1 , %SEE= 8.62): VO2max (mL·kg -1· min -1 ) = 48.0730 + (6.1779 x gender; women = 0, men = 1) – (0.2463 x age) – (0.6186 x BMI) + (0.7115 x PFA) + (0.6709 x PA-R). Cross validation using PRESS (predicted residual sum of squares) statistics revealed minimal shrinkage (R p = .91 and SEE p = 3.63 mL·kg -1· min -1 ); thus, this model should yield acceptable accuracy when applied to an independent sample of adults (ages 18–-65 years) with a similar cardiorespiratory fitness level. Based on standardized β-weights, the PFA variable (0.41) was the most effective at predicting VO2max followed by age (-0.34), gender (0.33), BMI (-0.27), and PA-R (0.16). This study provides a N-EX regression model that yields relatively accurate results and is a convenient way to predict VO2max in adult men and women.  相似文献   
997.
Abstract

Hearts from 126 male Sprague-Dawley rats (two age groups) were studied to determine effects of age, chronic hypoxia, and exercise on ventricular weight. Exercised rats had significantly heavier absolute total ventricular weights (right plus left) compared with chronically hypoxic or control rats. Whether expressed as absolute or percent total ventricular weight, chronically hypoxic rats had significantly larger right ventricles but significantly smaller left ventricles than exercised or control rats. Expressed as absolute weight, older rats (11 months) had significantly larger right or left ventricles than young rats (3 months). Expressed as percent total ventricular weight, young rats had left ventricles 4% smaller, but right ventricles 4% larger than older rats (p <.05). Type of work overload (volume or pressure) and functional location of workload (pulmonary or systemic) were suggested physiological mechanisms for stress- and age-related changes in myocardial mass.  相似文献   
998.
Abstract

The efficiency of two practice schedules was examined on two large muscle motor tasks. There were four groups of subjects (N = 160); each individual in a group performed on one of the two motor tasks under one of the two conditions. Distributed practice consisted of alternating 30-second trials of practice and rest; massed practice was continuous for 8 minutes. Comparisons made during the last minute of practice prior to the rest pause revealed that the massed groups had significant decrements in performance level. In contrast, after the rest period, when both groups were on a distributed schedule, no difference was found in the amount of learning. Learning was found to be a function of the number of trials and independent of the conditions of practice.  相似文献   
999.
Abstract

The purpose of this study was to determine the relationship between the prestige of physical education graduate departments where faculty obtained their doctorates and the prestige of physical education graduate departments where faculty are now employed. Based on previous research in other academic disciplines, it was expected that graduates from the most prestigious departments tend to be employed at the most prestigious institutions; that their proportion declines as the institutional prestige of the doctoral granting institution declines; and that the institutional inbreeding of doctoral graduates in physical education will be the highest among the most prestigious institutions. Subjects (N = 795) were regular resident faculty with earned doctorates who were employed at any one of the 58 highest physical education doctoral degree producing institutions. A multiple regression analysis revealed a significant relationship (.01) between prestige of doctoral granting department and prestige of employing department. Data indicated that faculty positions at institutions ranking in the top 20 were available almost exclusively to graduates from the top 20, and that the higher the prestige of a department the greater the inbreeding of the faculty. Findings clearly supported the “sponsored” model of career mobility patterns rather than the “contest” model.  相似文献   
1000.
Purpose: The purpose of this study was to determine the reliability of cardiorespiratory and pelvic kinematic responses to simulated horseback riding (SHBR) and to characterize responses to SHBR relative to walking in apparently healthy children. Method: Fifteen healthy children (Mage = 9.5 ± 2.6 years) completed SHBR on a commercially available simulator at low intensity (0.27 Hz) and high intensity (0.65 Hz) during 3 sessions on different occasions. Heart rate (HR), blood pressure, and respiratory gases were measured at rest and during steady-state exercise at both intensities. Pelvic displacement was measured during steady-state exercise. Rate of energy expenditure, mean arterial pressure, and rate pressure product (RPP) were calculated. Participants also walked on a treadmill for 26.8 m/min to 80.5 m/min in 13.4-m/min increments at 0% grade during 1 session to compare cardiorespiratory responses with those of SHBR. Results: Physiological variables across all 3 SHBR sessions were similar at both intensities (p>.05 for all). Intraclass correlation coefficients (ICCs) and coefficients of variation indicate good to modest reliability of cardiorespiratory measures during SHBR (ICCs = .542–.996 for oxygen consumption, energy expenditure, and RPP). Cardiorespiratory variables, except for HR, were 2% to 19% greater, and pelvic displacement was up to 37% greater with high-intensity riding. Treadmill walking at all speeds elicited greater physiological responses compared with SHBR (p < .05). Conclusion: Cardiorespiratory responses and pelvic kinematics are reproducible with SHBR in young children, and these responses were lower than those elicited by slow treadmill walking.  相似文献   
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