The effect of marathon running on carnitine metabolism and on some aspects of muscle mitochondrial activities and antioxidant mechanisms

Carnitine is an essential co‐factor in the catabolism of fats as an energy source. The primary purpose of this study was to investigate the effect of running a marathon on the metabolism of carnitine by endurance‐trained athletes, and to evaluate the effect of carnitine administration on the performance of such exercise. The effects of marathon running on mitochondrial enzymes and cellular anti‐oxidants were also examined to assess whether the expression of these activities is altered by exercise. Subjects were 10 experienced male marathon runners aged between 19 and 25 years. Running a marathon caused a fall in the plasma content of unesterified carnitine (37%) and an increase in the level of acetylcarnitine present (288%). Loading of the athletes with L‐carnitine for 10 days before running a marathon abolished the exercise‐induced fall in plasma‐free carnitine (P<0.05) whilst amplifying the production of acetylcarnitine (P<0.05). Carnitine loading of the athletes studied made no detectable improvement in performance of the marathon (P > 0.05). Cytochrome oxidase, succinate cytochrome C reductase and Superoxide dismutase activities present in skeletal muscle were unaltered by marathon running. However, such exercise caused a large increase in the tissue content of oxidized glutathione (189%) at the expense of reduced glutathione (–18%).     

Effect of Hand Spacing and Rear Knee Angle on the Sprinter's Start

Abstract

Twelve male subjects with no specialized training in sprint running were used to study effects upon the sprinter's start when hand spacing and rear knee angle were systematically altered. Results indicated that hand spacing had an effect on the start during the first 10 yd. of the sprint. The effect of rear knee angle was present at 10 yd. and the advantage gained at 10 yd. was still present at 30 yd.     

Effect of the coefficient of friction of a running surface on sprint time in a sled-towing exercise

This study investigated the effect of the coefficient of friction of a running surface on an athlete's sprint time in a sled-towing exercise. The coefficients of friction of four common sports surfaces (a synthetic athletics track, a natural grass rugby pitch, a 3G football pitch, and an artificial grass hockey pitch) were determined from the force required to tow a weighted sled across the surface. Timing gates were then used to measure the 30-m sprint time for six rugby players when towing a sled of varied weight across the surfaces. There were substantial differences between the coefficients of friction for the four surfaces (μ = 0.21–0.58), and in the sled-towing exercise the athlete's 30-m sprint time increased linearly with increasing sled weight. The hockey pitch (which had the lowest coefficient of friction) produced a substantially lower rate of increase in 30-m sprint time, but there were no significant differences between the other surfaces. The results indicate that although an athlete's sprint time in a sled-towing exercise is affected by the coefficient of friction of the surface, the relationship relationship between the athlete's rate of increase in 30-m sprint time and the coefficient of friction is more complex than expected.     

Maintaining at-risk children in regular education settings: initial effects of individual differences and classroom environments

This study described the course of school failure by classifying the characteristics of 103 first-grade children who were at risk for such an outcome and examining their classroom environments over a 1- to 4-year period. We describe the association between empirically validated clusters of children and specific instructional arrangements that served to increase the risk of special education placement. We found that individual seatwork while other children were in a reading group significantly increased the risk of placement; on the other hand, small-group work was associated with nonplacement for one cluster of children (those with possible learning disabilities). Other results were inconclusive, but suggestive of patterns that may eventually assist in the definition of the elusive link between individual differences and classroom environments.     

Teaching in the ‘margins’: rekindling a passion for teaching

The data for this paper are drawn from a qualitative research project involving a number of alternative education sites in Australia and the United Kingdom. In this paper, we focus only on the motives and teaching philosophies of a sample of teachers who have chosen to work in alternative education sites despite, for some, the prospect of uncertain employment conditions and lower salaries. A thematic approach is used with the data so as to structure participant perspectives on a range of teaching-related issues. We argue that the experiences and perceptions of these teachers provide a starting point for reflection about the impact of many current educational policies that have been shaped or influenced by market-driven neo-liberal paradigms emphasising disciplinary accountabilities for teachers.     

Influence of academic self-regulation,critical thinking,and age on online graduate students’ academic help-seeking

Academic help-seeking is an invaluable learning strategy that has not yet received much attention in the distance education research literature. The asynchronous nature of distance education and many online courses presents an inherent roadblock to help-seeking. The purpose of this study was to explore the effect of academic self-regulation, critical thinking, and age on online graduate students’ help-seeking. Results indicate that these variables did significantly influence help-seeking, and that as self-regulation and critical thinking increased so did help-seeking. However, as age increased, help-seeking decreased. These results and implications for practice are discussed.     

Boys Don't Cry and female masculinity: reclaiming a life & dismantling the politics of normative heterosexuality

–This analysis argues that Kimberly Peirce's film Boys Don't Cry can be read as a liberatory narrative that queers the centers of heteronormativity and hegemonic masculinity by privileging female masculinity and celebrating its differences from heterosexual norms. My critique emphasizes how the narrative strategically challenges heteronormativity and, in turn, “narrative's heteroideology” (Roof, 1996), in four ways: 1) by dismantling the myth of “America's heartland”; 2) by problematizing heteromasculinity; 3) by centering female masculinity; and 4) by blurring the boundaries of female masculinity. I argue that the articulation of each subversive strategy within the narratives of Boys Don't Cry can serve a liberatory function, whereby the privileged subjectivities of heterosexuality and hegemonic masculinity are dismantled and, simultaneously, female masculinity and gender fluidity are privileged and normalized. I conclude that the narrative structure of Boys Don't Cry not only privileges gender diversity, but also exposes the inherent sexual bigotry of heteroideology and the brutal and deadly consequences of society's failure to eradicate such prejudice. I just keep on laughing Hiding the tears in my eyes Because boys don't cry. Boys don't cry. (Smith, Tolhurst, & Dempsey, 1988)