Changes in Myocardial Mass Associated with Age and Stress: Reexamination of Ventricular Hypertrophy

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.     

Efficiency of Motor Learning as a Function of Intertrial Rest

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.     

Departmental Prestige and Career Mobility Patterns of College Physical Educators

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.     

Using Principal Components Analysis to Identify Individual Differences in Vertical Jump Performance

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 (M_age = 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.     

The Differential Effects of Human Capital for Male and Female Division I Basketball Coaches

Abstract

A horizontal adductive arm swing executed at maximal speed, and timed at intervals of 15°, 53°, 90°, and 105°, was studied under two experimental conditions. Although the movement completed was the same in both conditions, the fundamental difference between the “normal” and “pre-tensed” arm movements was that in the latter condition the subject built up his arm strength maximally just prior to initiating the movement. Twenty trials under each condition was performed by 60 college men. All reliability coefficients were found to be high, i.e., over .89. In contradiction to expectations, the relationship between premovement strength and speed of movement at the first station (r = -.208) was lower than anticipated. However, the low correlations found between strength and speed of movement are in general agreement with the results of earlier investigators which have substantiated the predominance of neuromotor specificity.     

Sixth Graders’ Co-construction of Explanations of a Disturbance in an Ecosystem: Exploring relationships between grouping,reflective scaffolding,and evidence-based explanations

We report on a study investigating the relationship between cognitive ability grouping, reflective inquiry scaffolding, and students’ collaborative explanations of an ecosystem disturbance which took place when a number of flamingo birds died in a salt lake because of nearby intensive human activities. Twenty-six pairs of students from two intact sixth-grade classes participated in the study. All students investigated scientific data relating to the ecosystem problem using a web-based learning environment. One class was provided with web-based reflective inquiry scaffolding (WorkSpace), while the other class used PowerPoint. The main data analyzed for this study consisted of each pair’s written explanation and task-related artifacts. Findings show that the web-based reflective scaffolding supported students in providing valid evidence in support of their explanations. The analyses of the students’ collaborative explanations showed no statistically significant differences that could be attributed to prior achievement between students in the WorkSpace condition, while differences were found between the different cognitive ability pairs in the PowerPoint class. These findings suggest that the WorkSpace scaffolding may have provided more influential support to lower cognitive ability pairs in creating evidence-based explanations.     

Sexual Justice Is Social Justice: An Activity to Expand Social Work Students Understanding of Sexual Rights and Injustices

Social work education could benefit from an explicit educational framework that combines social justice and sexuality: sexual justice. However, there is a paucity of literature in social work discussing this critical issue. This article helps equip social workers to challenge social injustice through a lens of sexuality and builds a conceptual framework by examining sexual justice through pillars of social work: human dignity, community and solidarity, rights and responsibilities, priority for the poor and vulnerable, and peace. An activity providing micro and macro case discussions is presented to help infuse sexual justice into social work programs.     

Examining the effects of home literacy and numeracy environment on early reading and math acquisition

The present study examined how the home literacy and numeracy environment in kindergarten influences reading and math acquisition in grade 1. Eighty-two Greek children from mainly middle socioeconomic backgrounds were followed from kindergarten to grade 1 and were assessed on measures of nonverbal intelligence, emergent literacy skills, early math concepts, verbal counting, reading, and math fluency. The parents of the children also responded to a questionnaire regarding the frequency of home literacy and numeracy activities. The results of path analyses indicated that parents’ teaching of literacy skills predicted reading fluency through the effects of letter knowledge and phonological awareness. Storybook exposure predicted reading fluency through the effects of vocabulary on phonological awareness. Finally, parents’ teaching of numeracy skills predicted math fluency through the effects of verbal counting. These findings suggest that both the home literacy and the home numeracy environments are important for early reading and math acquisition, but their effects are mediated by emergent literacy and numeracy skills.