The effects of substrate and fluid provision on thermoregulatory and metabolic responses to prolonged exercise in a hot environment

A high ambient temperature reduces the capacity to perform prolonged exercise. Total carbohydrate oxidation is less, and thus glycogen depletion is not limiting. Fluid ingestion in the heat should, therefore, focus on maintenance of hydration status rather than on substrate provision. Six healthy males cycled to exhaustion at 60% of maximum oxygen consumption (VO2max) with no drink, ingestion of a 15% carbohydrate-electrolyte drink (1.45+/-0.29 litres) or ingestion of a 2% carbohydrate-electrolyte drink (3.12+/-0.47 litres). The ambient temperature was 30.2+/-0.6 degrees C (mean +/- s), with a relative humidity of 71+/-1% and an air speed of approximately 0.7 m x s(-1) on all trials. Weighted mean skin temperature, rectal temperature and heart rate were recorded and venous samples drawn for determination of plasma volume changes, blood metabolites, serum electrolytes and osmolality. Expired gas was collected to estimate rates of fuel oxidation. Exercise capacity was significantly (P < 0.05) different in all trials. The median (range) time to exhaustion was 70.9 min (39.4-97.4 min) in the no-drink trial, 84.0 min (62.7-145 min) in the 15% carbohydrate trial and 118 min (82.6-168 min) in the 2% carbohydrate trial. The 15% carbohydrate drink resulted in significantly (P < 0.05) elevated blood glucose and total carbohydrate oxidation compared with the no-drink trial. The 2% carbohydrate drink restored plasma volume to pre-exercise values by the end of exercise. No differences were observed in other thermoregulatory or cardiorespiratory responses between trials. These results suggest that fluid replacement with a large volume of a dilute carbohydrate drink is beneficial during exercise in the heat, but the precise mechanisms for the improved exercise capacity are unclear.     

The role of cross-disciplinary academic language skills in disciplinary,source-based writing: investigating the role of core academic language skills in science summarization for middle grade writers

Reading and Writing - Learning to use language in order to complete source-based writing tasks is a challenge for middle grade writers worthy of additional study, especially given that these tasks...     

Achieving accurate metrics using balanced scorecards and dashboards

The balanced scorecard was developed to align business practices with the overall strategy of an organization and to monitor performance. A dashboard is a computer interface designed to receive and manipulate data from the various departments within a company to present comprehensive information to decision makers. The balanced scorecard, when combined with the dashboard, provides a way for organizations to determine strategy and evaluate performance.     

How do approaches to solving open-ended problems vary within the science disciplines?

This paper describes the results of a comparative study into the approaches used by science undergraduates when solving open-ended problems. This study adopted a pseudo-grounded theory framework to analyse six case studies, one from each of the science disciplines studied. The study involved 70 participants from 5 institutions solving open-ended problems using a think-aloud protocol. Analysis of the data identified a number of different approaches used by each subject group. Participants in psychology, pharmacy and sports rehabilitation used a greater number of novice-like approaches than participants in chemistry, physics and interdisciplinary science. The approaches used by physical science participants were very similar whereas those from pharmacy, sports rehabilitation and psychology were more varied and relied on students’ ability to relate to a familiar context. Evaluation of the relative quality of solutions showed variation with discipline.     

The effects of substrate and fluid provision on thermoregulatory and metabolic responses to prolonged exercise in a hot environment

A high ambient temperature reduces the capacity to perform prolonged exercise. Total carbohydrate oxidation is less, and thus glycogen depletion is not limiting. Fluid ingestion in the heat should, therefore, focus on maintenance of hydration status rather than on substrate provision. Six healthy males cycled to exhaustion at 60% of maximum oxygen consumption (VO 2max ) with no drink, ingestion of a 15% carbohydrate-electrolyte drink (1.45 - 0.29 litres) or ingestion of a 2% carbohydrate-electrolyte drink (3.12 - 0.47 litres). The ambient temperature was 30.2 - 0.6°C (mean - s ), with a relative humidity of 71 - 1% and an air speed of approximately 0.7 m.s -1 on all trials. Weighted mean skin temperature, rectal temperature and heart rate were recorded and venous samples drawn for determination of plasma volume changes, blood metabolites, serum electrolytes and osmolality. Expired gas was collected to estimate rates of fuel oxidation. Exercise capacity was significantly ( P ? 0.05) different in all trials. The median (range) time to exhaustion was 70.9 min (39.4-97.4 min) in the no-drink trial, 84.0 min (62.7-145 min) in the 15% carbohydrate trial and 118 min (82.6-168 min) in the 2% carbohydrate trial. The 15% carbohydrate drink resulted in significantly ( P ? 0.05) elevated blood glucose and total carbohydrate oxidation compared with the no-drink trial. The 2% carbohydrate drink restored plasma volume to pre-exercise values by the end of exercise. No differences were observed in other thermoregulatory or cardiorespiratory responses between trials. These results suggest that fluid replacement with a large volume of a dilute carbohydrate drink is beneficial during exercise in the heat, but the precise mechanisms for the improved exercise capacity are unclear.     

Nutrition and Biochemistry in the Journal of Sports Sciences: A call for papers and announcing the introduction of letters to the editor

Abstract

In association football, two similar but arguably different refereeing roles are required, those of the referee and assistant referee. Role specificity was investigated with a foul play assessment task and an offside decision-making task. Deliberate practice was investigated to account for role-specific differences. First, role specificity was clearly observed. Second, years of officiating, hours of practice per week, and number of matches officiated were each positively correlated with skill. The results support role specificity in association football refereeing. Further research should help to create role-specific perception and decision-making training programmes both for referees and assistant referees.     

Enhanced handling and positioning in early infancy advances development throughout the first year

Behaviors emerge, in part, from the interplay of infant abilities and caregiver–infant interactions. Cross‐cultural and developmental studies suggest caregiver handling and positioning influence infant development. In this prospective, longitudinal study, the effects of 3 weeks of enhanced handling and positioning experiences provided to 14 infants versus control experiences provided to 14 infants at 2 months of age were assessed with follow‐up through 15 months of age. Behaviors in prone were immediately advanced. Short‐term advancements occurred in multiple behaviors, including prone, head control, reaching, and sitting behaviors. Longer term advancements, up to 12 months after the experience period, occurred in object transfer, crawling and walking behaviors. This suggests broad and long‐lasting changes can arise via brief periods of change in caregiver–infant interactions.     

Sources of Stress for Class Teachers in New Zealand Primary Schools

The authors report on the findings of a case study of parent–teacher conferences in a secondary school in Hong Kong. They explored through interviews parents’ and teachers’ perspectives of parent–teacher conferences. They noted that parent–teacher conferences were sources of stress for teachers and embarrassment for parents. Parent–teacher conferences were useful for problem‐clarification. The building of mutual trust was the most important conferencing skill. They drew out some practical guidelines which were useful to teachers of the case study school but are also valuable to all teachers who wish to work effectively and positively with parents.     

Parent and teacher views of gifted children's social abilities

This study compared parent and teacher perceptions of gifted children's social skills and the importance these adults attach to different social skills. No significant differences were found on overall ratings of social skills. However, differences were found on specific social skills. Teacher ratings of cooperation were significantly higher than parents' and teachers valued cooperation highly. Parent ratings of assertion were significantly higher than teachers' and they valued assertion and self‐control over cooperation. Implications for the classroom and home are discussed.