The effects of exercise in hypoxic and normoxic conditions on endothelin-1 and arterial compliance

The purpose of this study was to determine the effects of short-term normoxic and hypoxic exercise on plasma endothelin-1 and nitric oxide levels, and the relationship of arterial compliance and pulmonary artery pressure to endothelin-1. Seven endurance-trained males completed two incremental and two steady-state exercise tests performed at ventilatory threshold in normoxia and hypoxia (fraction of inspired oxygen = 0.14). Plasma endothelin-1was measured throughout steady-state tests. Arterial compliance using applanation tonometry, plasma nitric oxide and pulmonary artery pressure using Doppler echocardiography were measured before and after exercise. Small arterial compliance and pulmonary artery pressure significantly increased following exercise. There were no main effects of condition or time for plasma endothelin-1and nitric oxide levels. There were no significant relationships between plasma endothelin-1 and arterial compliance or pulmonary artery pressure. In conclusion, mechanisms other than the endothelial system may play a role in the exercise-induced changes in small artery compliance in this study population. Moderate hypoxia and a 30-minute steady-state exercise have limited effects on plasma endothelin-1 in endurance-trained males.     

The Impact of an Obstacle Course Sport Education Season on Students' Aerobic Fitness Levels

Abstract

The purpose of this study was to determine if factor patterns of selected sports skills were similar for two samples, a skilled sample and one consisting of a wide range of skills. Comparisons were also made with kinesiological evidence regarding the patterning of basic sports skills. Data consisting of performance scores on various sports skills were available for 166 high school girls. Out of this sample, a smaller sample was drawn consisting of 69 girls who were above average in skill. Two factor models, alpha and incomplete image analysis, were used in the analysis of this data. The factor pattern of selected sports skills performed by subjects above average in skill was similar in many respects to that of a sample which included a wide range of skill. The primary difference lay in the clustering of overarm skills which appeared in the above-average factor pattern. The overarm and push patterns of the above-average sample resembled the patterns of skill obtained through kinesiological analysis. The structure of kicking, underarm, and sidearm skills remained obscure, based on the results of factor analytic techniques.     

But I like PE: factors associated with enjoyment of physical education class in middle school girls

The current study examined associations between physical education (PE) class enjoyment and sociodemographic, personal, and perceived school environment factors among early adolescent girls. Participants included 1,511 sixth-grade girls who completed baseline assessments for the Trial of Activity in Adolescent Girls, with 50% indicating they enjoyed PE class a lot. Variables positively associated with PE class enjoyment included physical activity level, perceived benefits of physical activity, self-efficacy for leisure time physical activity, and perceived school climate for girls' physical activity as influenced by teachers, while body mass index was inversely associated with PE class enjoyment. After adjusting for all variables in the model, PE class enjoyment was significantly greater in Blacks than in Whites. In model testing, with mutual adjustment for all variables, self-efficacy was the strongest correlate of PE class enjoyment, followed by perceived benefits, race/ethnicity, and teachers' support for girls' physical activity, as compared to boys, at school. The overall model explained 11% of the variance in PE class enjoyment. Findings suggest that efforts to enhance girls' self-efficacy and perceived benefits and to provide a supportive PE class environment that promotes gender equality can potentially increase PE class enjoyment among young girls.     

Differential reactions to assertive and communicative acts of toddler boys and girls

34 children were observed in infant play groups. 2 sets of infant behaviors were coded: assertive acts and attempts to communicate with adults. No sex differences were observed at 13 to 14 months in any of these behaviors. However, adults attended to girls' assertive behaviors far less of the time than to boys' assertive behaviors. They attended more to girls' less intense communication attempts and to boys' more intense attempts. When 29 of the same children were observed in toddler play groups no more than 11 months later, there were sex differences in behavior. Boys were more assertive; girls talked to teachers more. Teachers no longer differentiated their responses to boys and girls. Peers reacted more to boys' assertive behavior than to girls.' We hypothesized that caregivers may use stereotypes to guide their reactions to infants because infant behavior is ambiguous. For the toddlers, behavior had become more defined, and caregivers reacted to the behaviors. By using the sex stereotype to guide their reactions to younger children, the caregivers may have perpetuated the stereotype.     

Confirmatory factor analysis of word recognition and process measures in the Colorado Reading Project

Measures of word recognition (REC) and two component skills, phonological coding (PHON) and orthographic coding (ORTH), were subjected to multivariate behavioral genetic analysis. Data were obtained from a sample of identical and fraternal twin pairs wherein at least one member of each pair was reading disabled (RD), and from a sample of twins wherein both members of each pair read in the normal range. Confirmatory factor analysis was used to fit the genetic, common environmental, and specific environmental covariance components for REC, PHON, and ORTH within the RD and normal simples. The resulting heritability estimates for REC, PHON, and ORTH were 0.59, 0.41, and 0.05 in the RD sample, and 0.35, 0.52, and 0.20 in the normal sample. After dropping the nonsignificant common environment parameters from the models, the genetic correlations between REC and PHON and between REC and ORTH were respectively 0.81 and 0.45 in the RD sample, and 0.68 and 0.45 in the normal sample. Differences between the genetic correlations were significant in the RD sample (p<0.005), marginally significant in the normal sample (p<0.10), and highly significant in the combined sample (p<0.001), indicating that genetic influences on individual differences in REC are more strongly related to genetic variance in PHON than in ORTH. These results are consistent with previous demonstrations of substantial genetic covariance between the disabled group's deficits in REC and PHON, but not between REC and ORTH (Olson et al., 1989; Olson and Rack, 1990).     

A regional cooperative acquisition program for monographs.

A cooperative acquisition program for monographs for the twelve resource libraries in Region IX of the Regional Medical Library Network is described. Each of the participating libraries has agreed to purchase all books of an assigned publisher which fall within a prescribed subject-format profile. It is hoped that this will help to reduce unnecessary duplication and contribute toward the development of resources in the region.     

A longitudinal examination of African American adolescents' attributions about achievement outcomes

Developmental, gender, and academic domain differences in causal attributions and the influence of attributions on classroom engagement were explored longitudinally in 115 African American adolescents. In Grades 8 and 11, adolescents reported attributions for success and failure in math, English and writing, and science. In Grade 11, English and mathematics teachers rated students' classroom engagement. Boys were more likely than girls to attribute math successes to high ability and to attribute English failures to low ability. Both genders' ability attributions for math became more negative from eighth to eleventh grades. Grade 8 attributions of math failure to lack of ability were negatively related to Grade 11 math classroom engagement. Results illustrate the gendered nature of motivational beliefs among Black youth.     

“I’ve Tried and I’ve Died This Year”: First-Year Teachers Reflect on Literacy Reform

This article describes the challenges associated with outcomes-based education reform as experienced by two novice elementary teachers. Interviews with the teachers provide insights into the tensions between their teaching beliefs and the practices employed in their local contexts. Specifically, pressures to both focus on standardized measures of student achievement and to conform to the social norms of the schools are explored. The authors advocate for the need for situated discussions about these tensions during the first year of teaching and recognition of the complexity of teaching and learning by all stakeholders.