Cellular adaption to repeated eccentric exercise-induced muscle damage

Eccentrically biased exercise results in skeletal muscle damage and stimulates adaptations in muscle, whereby indexes of damage are attenuated when the exercise is repeated. We hypothesized that changes in ultrastructural damage, inflammatory cell infiltration, and markers of proteolysis in skeletal muscle would come about as a result of repeated eccentric exercise and that gender may affect this adaptive response. Untrained male (n = 8) and female (n = 8) subjects performed two bouts (bout 1 and bout 2), separated by 5.5 wk, of 36 repetitions of unilateral, eccentric leg press and 100 repetitions of unilateral, eccentric knee extension exercises (at 120% of their concentric single repetition maximum), the subjects' contralateral nonexercised leg served as a control (rest). Biopsies were taken from the vastus lateralis from each leg 24 h postexercise. After bout 2, the postexercise force deficit and the rise in serum creatine kinase (CK) activity were attenuated. Women had lower serum CK activity compared with men at all times (P < 0.05), but there were no gender differences in the relative magnitude of the force deficit. Muscle Z-disk streaming, quantified by using light microscopy, was elevated vs. rest only after bout 1 (P < 0.05), with no gender difference. Muscle neutrophil counts were significantly greater in women 24 h after bout 2 vs. rest and bout 1 (P < 0.05) but were unchanged in men. Muscle macrophages were elevated in men and women after bout 1 andbout 2 (P < 0.05). Muscle protein content of the regulatory calpain subunit remained unchanged whereas ubiquitin-conjugated protein content was increased after both bouts (P < 0.05), with a greater increase after bout 2. We conclude that adaptations to eccentric exercise are associated with attenuated serum CK activity and, potentially, an increase in the activity of the ubiquitin proteosome proteolytic pathway.

Game-centred models and teaching in culturally diverse settings

This presentation draws on the observations and experiences that we, as teacher educators, have had using Teaching Games for Understanding (TGfU) as a pedagogical tool with generalist pre-service teachers in two different sites: Malaysia and Australia. TGfU is a game-centred pedagogy in which students learn the „Why‟ of game playing before the „How‟ of the skills associated with the game. This concept is based on a student-centred approach to learning. The benefit of this pedagogy to generalist teachers is the notion that they are not required to be a master of many sports. This narrative relates the observations and experiences of teacher educators of Malaysian and Australian generalist pre-service teachers confronted with teaching and learning TGfU for the first time in their culturally specific contexts. The two key issues arising from teaching the TGfU model were: the disparity in the cohorts‟ experiences arising from institutionalised conceptions by the pre-service teachers of what and how learning occurs in physical education; and the pre-service teachers‟ difficulty with implementing the TGfU model in a practical situation. Crossing the cultural divide for the Malaysian and Australian pre-service teachers required them to explore more fully the range of approaches to teaching and to recognise a more student-centred approach as a valid and authentic tool. As both teachers and observers of this process, our intention was to examine the two cohorts‟ learning and subsequent teaching with the aim of developing better understandings of the challenges when teaching TGfU in tertiary settings.

Psychological and cumulative cardiovascular effects of repeated angry ruminaton and visuospatial suppression

Brooding rumination is associated with depressed mood, increased negative affect, prolonged anger and inhibited cardiovascular (CV) recovery. Distraction from rumination on a stressful interpersonal encounter is associated with faster CV recovery and decreased negative affect. Studies have suggested that a concurrent visuospatial (VS) task inhibits the maintenance of imagery associated with the perseveration of intrusive negative memories. 120 healthy participants were recruited for the study. As an analogue of repeated angry rumination, the authors explored the effects of repeated visual recall of a provocative confederate and the subsequent impact of two visuospatial (VS) distraction tasks on negative affect, blood pressure (BP) and heart rate (HR). Repeated recall of the provocation generated repeatedly elevated HR with a cumulative trend that may have CV disease risk implications for chronic ruminators. VS distraction did not aid recovery compared with the Control task.

Aggressive tax planning : differentiating those playing the game from those who don't

The study reported in this paper examined a group of Australian taxpayers who have expressed a preference for a creative and aggressive tax agent. The study attempted to understand how high-risk taxpayers and high-risk practitioners form their partnerships by examining aggressive taxpayers' attitudes and perceptions of the Australian tax system. Data were taken from 2040 Australian taxpayers who had responded to a national survey on tax issues. Results from a series of independent sample t-tests revealed that there are a number of important differences between 'aggressive' and 'non-aggressive' taxpayers. Finally, a logistic regression analysis was used to determine which variables most effectively differentiated aggressive taxpayers from non-aggressive taxpayers. The findings are discussed in a regulatory context and possible solutions for how tax authorities might deal with this high-risk group of taxpayer are suggested.

Endogenous transportation technology in a cournot differential game with intraindustry trade

We investigate a dynamic Cournot duopoly with intraindustry trade, where firms invest in R&D to reduce the level of iceberg transportation costs. We adopt both open-loop and closed-loop equilibrium concepts, showing that a unique (saddle point) steady state exists in both cases. In the open-loop model, optimal investments and the resulting efficiency of transportation technology are independent of the relative size of the two countries. On the contrary, in the closed-loop case firms’ R&D incentives are driven by the relative size of the two countries. Policy implications are also evaluated.

Divide-the-Dollar game revisited

In the Divide-the-Dollar (DD) game, two players simultaneously make demands to divide a dollar. Each player receives his demand if the sum of the demands does not exceed one, a payoff of zero otherwise. Note that, in the latter case, both parties are punished severely. A major setback of DD is that each division of the dollar is a Nash equilibrium outcome. Observe that, when the sum of the two demands x and y exceeds one, it is as if Player 1's demand x (or his offer (1−x) to Player 2) suggests that Player 2 agrees to λx < 1 times his demand y so that Player 1's demand and Player 2's modified demand add up to exactly one; similarly, Player 2's demand y (or his offer (1−y) to Player 1) suggests that Player 1 agrees to λyx so that λyx+y = 1. Considering this fact, we change DD's payoff assignment rule when the sum of the demands exceeds one; here in this case, each player's payoff becomes his demand times his λ; i.e., each player has to make the sacrifice that he asks his opponent to make. We show that this modified version of DD has an iterated strict dominant strategy equilibrium in which each player makes the egalitarian demand 1/2. We also provide a natural N-person generalization of this procedure.

Do young children get the message? The effects of repeated video viewing on explicit and implicit information

The aim of this study was to explore the effects of repeat viewing on comprehension of explicitly and implicitly presented information in an animated movie. Seventy-three pre-school children watched an animated film and were tested for comprehension after either their single or fifth viewing. Only children’s comprehension of explicitly presented information was facilitated by repeat viewing. However, post hoc analyses revealed that children’s explicit and implicit comprehension of a central character Thunderbolt significantly increased across viewing conditions, whereas, repeat viewing only facilitated children’s explicit comprehension of the central character Patch. The theoretical and practical implications of these findings are discussed.

Repeated-viewing and co-viewing of an animated video : an examination of factors that impact on young children's comprehension of video content

The experiment reported here was concerned with the effect of repeat- viewing and adult co-viewing on the comprehension of an animated feature length movie. Four- to six-year-old children watched a movie on video either once or five times, and either with their mother present or on their own. The findings revealed that, after controlling for language skills and interest in the type of video watched, children who watched five times had higher comprehension scores than children who watched only once. Furthermore, children who watched the video repeatedly were also better at character identification and at identifying the good and bad qualities of one of the main characters in the movie. The presence of a mother, who was explicitly asked to co- view the movie with her child, did not facilitate comprehension. The findings are discussed in terms of the educational benefits of repeat viewing. Theoretical implications are also noted.