Motivational control after extended instrumental training

Hungry rats were trained to press a lever for food pellets prior to an assessment of the effect of a shift in their motivational state on instrumental performance in extinction. The first study replicated the finding that a reduction in the level of food deprivation has no detectable effect on extinction performance unless the animals receive prior experience with the food pellets in the nondeprived state (Balleine, 1992; Balleine & Dickinson, 1994). When tested in the nondeprived state, only animals that were reexposed to the food pellets in this state between training and testing showed a reduction in the level of pressing during the extinction test relative to animals tested in the deprived state. The magnitude of this reexposure effect depended, however, on the amount of instrumental training. Following more extended instrumental training, extinction performance was unaffected by reexposure to the food pellets in the nondeprived state whether or not the animals were food deprived at the time of testing. A second study demonstrated that the resistance to the reexposure treatment engendered by overtraining was due to the animals’ increased experience of the food pellets in the deprived state during training rather than to the more extensive exposure to the instrumental contingency. In contrast to the results of the first two experiments, however, a reliable reexposure effect was detected after overtraining in a final study, in which the animals were given greater reexposure to the food pellets in the nondeprived state.     

Early means early: understanding popular understandings of early childhood development in South Africa

Scientific and policy advances are putting early childhooddevelopment (ECD) at the center of efforts to improve humandevelopment. This study was undertaken to understand whatknowledge and attitudinal barriers exist that 25 hinder the full-scaleroll-out of services for the youngest children and their families.We used anthropological methods honed by the FrameworksInstitute to plumb beliefs about early childhood development amongmembers of the public and implementation and policy stakeholders,and compare those with the findings from ECD research. Whilemembers of the public and stakeholders agree on the importance ofECD, as demonstrated in other country settings, a major barrier todirecting services to the youngest children is a perceptual tendencyto ‘age up’. That is, to consider learning and other important skillsas being acquired in the pre-school rather than infancy period.Communication strategies that incorporate debate are neededto give full effect to the ECD and related policies, especiallyaround the topics of prioritizing the youngest 40 children, physicalpunishment, child rights, and the pervasiveness Q5 of threats toECD arising from poverty and disadvantage.     

The relationship between selected physiological variables of rowers and rowing performance as determined by a 2000 m ergometer test

The aim of this study was to establish the relationship between selected physiological variables of rowers and rowing performance as determined by a 2000 m time-trial on a Concept II Model B rowing ergometer. The participants were 13 male club standard oarsmen. Their mean (+/- s) age, body mass and height were 19.9+/-0.6 years, 73.1+/-6.6 kg and 180.5+/-4.6 cm respectively. The participants were tested on the rowing ergometer to determine their maximal oxygen uptake (VO2max), rowing economy, predicted velocity at VO2max, velocity and VO2 at the lactate threshold, and their velocity and VO2 at a blood lactate concentration of 4 mmol x l(-1). Percent body fat was estimated using the skinfold method. The velocity for the 2000 m performance test and the predicted velocities at the lactate threshold, at a blood lactate concentration of 4 mmol x l(-1) and at VO2max were 4.7+/-0.2, 3.9+/-0.2, 4.2+/-0.2 and 4.6+/-0.2 m x s(-1) respectively. A repeated-measures analysis of variance showed that the three predicted velocities were all significantly different from each other (P<0.05). The VO2max and lean body mass showed the highest correlation with the velocity for the 2000 m time-trial (r = 0.85). A stepwise multiple regression showed that VO2max was the best single predictor of the velocity for the 2000 m time-trial; a model incorporating VO2max explained 72% of the variability in 2000 m rowing performance. Our results suggest that rowers should devote time to the improvement of VO2max and lean body mass.     

Access to the online evidence base in general practice: a survey of the Northern and Yorkshire Region

Aims: To assess the awareness and use of NHSnet within general practice. To investigate the presence of skills necessary to maximize the benefits of NHSnet connections. Methods: Postal survey of general practice staff in the Northern and Yorkshire Region. Results: At least one completed questionnaire was obtained from 65% of the general practices surveyed, and the individual response rate to the general practice survey was 44%. Ninety per cent of all respondents reported that their practice was connected to the NHSnet, with 59% of respondents reporting that they use NHSnet at least once a week. Although NHSnet was used to search for research information or guidance, all respondents in this survey still reported greater access to and use of paper‐based information resources. Respondents indicated that they still needed further training on how to use NHSnet (42%), how to search the Internet (31%) and how to search electronic databases such as medline (49%). Conclusions: Since our 1999 survey, reported NHSnet connectivity has increased greatly, with a majority of respondents reporting that they use NHSnet at least once a week. Although encouraging, this level of usage suggests that using the Internet/NHSnet to find research has yet to become a core activity in general practice.     

Cycling

The resistance against a cyclist while riding on rollers is due mainly to rolling resistance produced by the deformation of the tyre as it rolls against small diameter drums. Resistance is then combined with wheel speed to set power output. The effect of tyre pressure and cross‐section on power was investigated by systematically altering the pressure (552 kPa, 690 kPa, and 827 kPa) in a 20c, 23c, 25c, and 28c tyre of the same design while riding at a wheel speed of 45 kph. Average power over 1 minute was measured with a Power Tap Hub (Tune Corporation, Cambridge, Massachusetts, USA) on five occasions. Statistical significance was evaluated at p < 0.05. Power requirements increased significantly with each reduction in tyre pressure for all tyres and pressures except the 25c between 690 and 827 kPa. The 20c tyre required significantly more power from the cyclist at each tested tyre pressure when compared to the other tyres (which were not different from each other). The differences in resistance from tyre size were not observed when ridden on the road. Additionally, a slightly different tyre design from the same manufacturer responded similarly in the 20c, but was significantly different in the 23c size. It was also observed that power requirements increased significantly when both the wheels were ridden on the rollers as compared to just the rear wheel. These results indicate that the power requirements may be significantly altered by the cyclist by adjusting tyre pressure, tyre cross‐section size, tyre type, and with the number of wheels contacting the rollers. However, the magnitude of these power requirements may not be suitable for intense workouts of trained cyclists.     

Physiological determinants of climbing-specific finger endurance and sport rock climbing performance

Abstract

The aim of the study was to examine several physiological responses to a climbing-specific task to identify determinants of endurance in sport rock climbing. Finger strength and endurance of intermediate rock climbers (n = 11) and non-climbers (n = 9) were compared using climbing-specific apparatus. After maximum voluntary contraction (MVC) trials, two isometric endurance tests were performed at 40% (s = 2.5%) MVC until volitional exhaustion (continuous contractions and intermittent contractions of 10 s, with 3 s rest between contractions). Changes in muscle blood oxygenation and muscle blood volume were recorded in the flexor digitorum superficialis using near infra-red spectroscopy. Statistical significance was set at P < 0.05. Climbers had a higher mean MVC (climbers: 485 N, s = 65; non-climbers 375 N, s = 91) (P = 0.009). The group mean endurance test times were similar. The force – time integral, used as a measure of climbing-specific endurance, was greater for climbers in the intermittent test (climbers: 51,769 N · s, s = 12,229; non-climbers: 35,325 N · s, s = 9724) but not in the continuous test (climbers: 21,043 N · s, s = 4474; non-climbers: 15,816 N · s, s = 6263). Recovery of forearm oxygenation during rest phases (intermittent test) explained 41.1% of the variability in the force – time integral. Change in total haemoglobin was significantly greater in non-climbers (continuous test) than climbers (P = 0.023 – 40% test timepoint, P = 0.014 – 60% test timepoint). Pressor responses were similar between groups and not related to the force – time integral for either test. We conclude that muscle re-oxygenation during rest phases is a predictor of endurance performance.     

Knowledge of attention deficit hyperactivity disorder (ADHD) and attitudes toward teaching children with ADHD: THE role of teaching experience

Knowledge of attention deficit hyperactivity disorder (ADHD) and attitudes toward teaching children with ADHD are compared across stages of Australian teachers' careers. Relative to pre‐service teachers with (n = 218) and without (n = 109) teaching experience, in‐service teachers (n = 127) show more overall knowledge of ADHD, more knowledge of characteristics and treatments for ADHD, and higher perceived knowledge. In‐service teachers reported less favorable emotion about teaching children with ADHD than did pre‐service teachers without experience and more favorable behaviors than pre‐service teachers with experience. Groups did not differ in knowledge of causes of ADHD, overall attitudes, stereotypical beliefs, and beliefs about teaching children with ADHD. Identification of knowledge gaps and ambivalent attitudes will guide pre‐service and in‐service training courses. © 2012 Wiley Periodicals, Inc.     

Ambivalent attitudes about teaching children with attention deficit/hyperactivity disorder (ADHD)

Drawing on attitude theories from social psychology, we conducted a survey of Australian pre-service (n = 327) and in-service (n = 127) teachers’ attitudes about teaching children with attention-deficit/hyperactivity disorder (ADHD). This paper reports a content analysis of beliefs, affect and behaviours towards teaching children with ADHD and quantitative analyses pertaining to attitudinal ambivalence – that is, where a teacher may simultaneously report negative and positive evaluations of teaching children with ADHD. While on average, overall or global attitudes were mildly positive for both cohorts, considerable ambivalence about teaching children with ADHD was commonly experienced. Participants reported ambivalent beliefs, affect and behaviours, as well as ambivalence between these attitude components. Paradoxically, participants who knew more about ADHD and held stronger positive global attitudes about teaching children with ADHD reported less ambivalent behaviours towards these children, but reported more ambivalent beliefs. The implications for teachers’ professional development and training are discussed.