Agreement in Body Fat Estimates Between a Hand-Held Bioelectrical Impedance Analyzer and Skinfold Thicknesses in African American and Caucasian Adolescents

Purpose: The aim of this study was to examine the effect of active versus passive recovery on 6 repeated Wingate tests (30-s all-out cycling sprints on a Velotron ergometer). Method: Fifteen healthy participants aged 29 (SD = 8) years old (body mass index = 23 [3] kg/m²) participated in 3 sprint interval training sessions separated by 3 to 7 days between each session during a period of 1 month. The 1st visit was familiarization to 6 cycling sprints; the 2nd and 3rd visits involved a warm-up followed by 6 30-s cycling sprints. Each sprint was followed by 4 min of passive (resting still on the ergometer) or active recovery (pedaling at 1.1 W/kg). The same recovery was used within each visit, and recovery type was randomized between visits. Results: Active recovery resulted in a 0.6 W/kg lower peak power output in the second sprint (95% confidence interval [CI] [ ? 0.2, ? 0.8 W/kg], effect size = 0.50, p < .01) and a 0.4 W/kg greater average power output in the 5th and 6th sprints (95% CI [+0.2,+0.6 W/kg], effect size = 0.50, p < .01) compared with passive recovery. There was little difference between fatigue index, total work, or accumulated work between the 2 recovery conditions. Conclusions: Passive recovery is beneficial when only 2 sprints are completed, whereas active recovery better maintains average power output compared with passive recovery when several sprints are performed sequentially (partial eta squared between conditions for multiple sprints = .38).     

Age Differences in Children's Ability to Model Motor Behavior

Abstract

In order to investigate the effects of modeling behavior for seven- and nine-year-old children, 30 seven-year-old and 30 nine-year-old females were randomly assigned within age level to three groups. These groups differed according to whether a model was presented at the beginning, midway, or not at all during 12 trials on the stabilometer. Both age groups were found to be similar in performance in the no model condition and, for both age groups, the beginning model condition was found to facilitate performance. However, the introduction of the model after six trials had a detrimental effect on the performance of younger children but facilitated older children's performance. These findings were interpreted in light of a likely increase in the processing capacity of nine year olds as well as an increase in the number of movement schemes that were previously stored in the older girls.     

The influence of moment of inertia on baseball/softball bat swing speed

The speed at which a player can swing a bat is central to the games of baseball and softball, determining, to a large extent, the hit speed of the ball. Experimental and analytical studies of bat swing speed were conducted with particular emphasis on the influence of bat moment of inertia on swing speed. Two distinct sets of experiments measured the swing speed of colege baseball and fast-pitch softball players using weighted rods and modified bats. The swing targets included flexible targets, balls on a tee and machine pitched balls. Internal mass alterations provided a range of inertial properties. The average measured speeds, from 22 to 31 m s⁻¹, are consistent with previous studies. Bat speed approximately correlates with the moment of inertia of the bat about a vertical axis of rotation through the batter's body, the speed generally decreasing as this moment of inertia increases. The analytical model assumes pure rotation of the batter/bat system about a vertical axis through the batter's body. Aerodynamic drag of the batter's arms and the bat is included in the model. The independent variable is bat moment of inertia about the rotation axis. There is reasonable agreement between the model and the measured speeds. Detailed differences between the two suggest the importance of additional degrees of freedom in determining swing speed.     

Multitrait-multimethod investigation of a novel body image measurement technique

A multitrait-multimethod (MTMM) matrix was used to evaluate validity evidence for a digital image manipulation (DIM) body image measurement technique in young women. One hundred one young women completed the DIM procedure and the Thompson and Gray (1995) Contour Drawing Rating Scale to measure self-ideal discrepancy and size perception accuracy components of body image. Seven-day test-retest reliability was acceptable (R = .81-.95). Convergent validity for self-ideal discrepancy was higher (r = .74) than the corresponding heterotrait, monomethod coefficients (r = .46, r = .23) and heterotrait-heteromethod coefficients (r = .18, r = .12). However, the convergent validity coefficient for size perception accuracy was r = .12. The pattern of correlations in the MTMM matrix met the criteria of Campbell and Fiske (1959) for validity of these procedures to measure self-ideal discrepancy but not size perception accuracy. The DIM procedure addresses some of the criticisms associated with figure-rating scales, such as unrepresentativeness of the figures, scale coarseness, and restriction of range in responses. DIM, therefore, represents a realistic, valid alternative to figure-rating scales for measuring self-ideal discrepancy.     

When Christian education meets patriotism: Christian organisations’ response to the introduction of Moral and National Education in Hong Kong schools

Plans by the Hong Kong Government to introduce moral and national education (MNE) as a compulsory subject in primary and secondary schools in 2010 encountered strong opposition. The controversy over the plans has lasted for two years, with the government and its supporters claiming that the subject will help to instil a stronger sense of national identity in children and critics deriding it as biased and constituting a form of brainwashing. The subject is also seen as posing troubles or a considerable threat to local Christian schools because most of them have had their own religious education programmes for years. Most Christian school-sponsoring bodies and parachurch organisations oppose the subject’s introduction, urging the government to scrap its curricular guidelines, and many say they will boycott its implementation. To bring the issues surrounding MNE into sharper focus, this article traces the development of Christian education in Hong Kong and analyses how local Christian communities perceive and have responded to the official proposal. Three prominent themes commonly emphasised in the Christian discourse are plural identities, conditional patriotism and universal values. These themes could shed light on wider theoretical discussion about the positive roles of religion and religious education for citizenship education.     

Maximising resource allocation in the teaching laboratory: understanding student evaluations of teaching assistants in a team-based teaching format

Minimal research papers have investigated the use of student evaluations on the laboratory, a learning medium usually run by teaching assistants with little control of the content, delivery and equipment. Finding the right mix of teaching assistants for the laboratory can be an onerous task due to the many skills required including theoretical and practical know-how, troubleshooting, safety and class management. Using larger classes with multiple teaching assistants, a team-based teaching (TBT) format may be advantageous. A rigorous three-year study across twenty-five courses over repetitive laboratory classes is analysed using a multi-level statistical model considering students, laboratory classes and courses. The study is used to investigate the effectiveness of the TBT format, and quantify the influence each demonstrator has on the laboratory experience. The study found that TBT is effective and the lead demonstrator most influential, influencing up to 55% of the laboratory experience evaluation.     

谁拥有智力?

传统的智力理论狭窄化甚至曲解了人类智力 ,但概念边界的过度扩展又使得智力概念失去真义。智力是单一的还是由多种能力构成 ?智力是否由遗传决定 ?智力的任何成分是否都可以准确测量 ?这三个尚未解决的问题主导着关于智力问题的讨论。在作者看来 ,这些问题已超出了学术讨论的范畴。     

The relationship between intelligence and performance on the test of variables of attention (TOVA)

The present study explored the relationship between the intelligence of young adults and their performance on the Test of Variables of Attention (TOVA). The study also examined whether significant differences existed between adults with and without attention-deficit/ hyperactivity disorder (ADHD) on TOVA errors of omission, errors of commission, mean correct response time, and variability, as well as on performance on the freedom from distractibility (FD) factor on the Wechsler Adult Intelligence Scale-Revised (WAIS-R). Seventy-nine adults participated in the study, including 17 with ADHD and 62 college students without ADHD. Pearson product-moment correlations indicated that none of the correlations between Full Scale IQ (FSIQ) and TOVA variables were significant. Analysis of variance results revealed that adults with ADHD made more errors of omission on the TOVA than did controls. Between-group differences were not found on the remaining dependent variables.