The belief revision model: asymmetrical effects of noncontingency on human covariation learning

A noncontingent experience affects the subsequent detection of positive and negative contingencies between the same events. Experiments 1 and 2 showed that such preexposure can produce both an impairment in the detection of subsequent positive contingency and a facilitation of a negative one, independent of the level of contingency during the contingent phase. Experiment 3 raised difficulties for a model that assumes that associations to the context can explain this asymmetrical effect. Experiment 4 suggested that the different weights usually assigned to the different types of trials when computing the contingency between events can change as a result of a noncontingent experience with the same events. This change supports an account of the asymmetrical effect by a belief revision model based on a mechanism that updates the weights of the different trial types as a function of previous experience. More generally, the belief revision model is a statistical (i.e., nonassociative) model of learning that is capable of accounting for trial-order effects, which have long posed problems for statistical models.     

运动训练对老年小鼠骨骼肌线粒体形态变化的电镜定量研究

通过计算机图象分析系统对小鼠骨骼肌线粒体结构进行形态计量分析,发现老年小鼠骨骼肌线粒体数目与年轻鼠无异,但肌膜下线粒体减少,线粒体总体积减小。长期运动训练可明显延缓线粒体形态结构的增龄性改变,使其功能有所改善。     

浙江省优秀划船运动员赛前血清某些激素浓度的变化

通过比较划船运动员赛前和平时( 对照)血清中某些激素的水平,发现有明显差异,女性睾酮从1 .59 下降至1 .18nmol/L,男性睾酮则从18 .93 上升21.69nmol/L;女性皮质醇从543 .4 下降至206.0nmol/L,男性皮质醇从543.7 下降至226 .0nmol/L,男性雌二醇从0.158 上升至0 .310pg/L;T3 及T4 均有显著性下降。结果表明优秀划船运动员赛前晨起血清激素水平较好,有利于运动员发挥最佳水平,同时有调动免疫系统,起到保护机体的作用。     

“Let’s make lots of money”: the determinants of performance in the recorded music sector

This research analyzes the performance of 467 record labels in eight European countries over a period of 13 years (2003–2015). The main goal is to explain a relative measure of profitability in terms of observed variables, although the nature of the dataset also allows us to include non-observed firm and country effects. To this end alternative models are estimated and three main research questions are tested, namely: (1) the effect of the dual structure of the recorded music market, in which a competitive segment and an oligopoly coexist; (2) the extent and source of the volatility of profits in record labels; and (3) the nonlinear impact of size on performance.     

Analysis of foot strike pattern,rearfoot dynamic and foot rotation over childhood. A cross-sectional study

The purpose of this study was to determine the foot strike patterns (FSP), rearfoot position at initial contact (RPic, i.e., No INV/EVE) and foot rotation in children in relation to age. A total of 932 children aged 3 to 16 years participated in this study. A sagittal and frontal-plane video was recorded using a high-speed camcorder to analyse these variables. There is a significant increase (p < 0.001) of rearfoot strike patterns (RFS) prevalence in relation to age; e.g. preschool children (3–6 years old) displayed an RFS prevalence 46.65% and the adolescent population(15–16 years old) an RFS prevalence 92.20%. The total RFS prevalence in all samples was 69.25%. There was a significant reduction (p < 0.001) of prevalence of RPic in relation to age groups; preschool children displayed a prevalence of RPic 60.37% and the adolescent population 10%. There was a significant reduction (p < 0.001) of prevalence of no foot rotation in relation to age groups; preschool children displayed a prevalence of no foot rotation 48.95% and the adolescent population 13.55%. In conclusion, FSP in children are influenced by age. It is noteworthy that the RFS prevalence of children is lower in comparison to the adult population.     

The Influence of Feedback on Competence,Motivation, Vitality,and Performance in a Throwing Task

Purpose: The purpose of this work is focused on the study of the effect that feedback has on competence valuation, perceived competence, autonomous motivation, vitality, and performance in a throwing task. Method: Thirty-five college students (26 men and 9 women), without previous experience in the task, participated in this study. The students were randomly assigned to three experimental conditions (positive, negative, and lack of feedback). Results: The results of this study point out that only those who received positive feedback before the handball throwing task, in contrast to those who received negative feedback or did not receive any feedback, showed increased levels of competence valuation (p < .05, Cliff’s delta effect size = ?.30), perceived competence (p < .001, Cliff’s delta effect size = ?.77), and autonomous motivation (p < .05, Cliff’s delta effect size = ?.48). This group also presented higher levels of perceived competence (p < .001, Cliff’s delta effect size = ?.84) and subjective vitality (p < .001, Cliff’s delta effect size = ?.80) than the group who received negative feedback after the throwing task. Those who received positive feedback also showed a higher throwing speed at the end of task than those who received negative feedback (p < 0.001, Cliff’s delta effect size = ?.71) or than those who did not receive any feedback (p < .05, Cliff’s delta effect size = ?.56). Conclusions: Competence valuation, perceived competence, autonomous motivation, subjective vitality, and throwing speed were favorably influenced by positive feedback. These results have important implications for the training style applied by coaches.     

Cardiorespiratory fitness and arm bone mineral health in young males with spinal cord injury: the mediator role of lean mass

Spinal cord injury (SCI) derives in loss of bone mineral content (BMC) and bone mineral density (BMD). However, physical activity is an important determinant in bone mass acquisition, which is partially mediated through the lean mass (LM). The aim was to examine the effect of cardiorespiratory fitness (CRF) on BMD and BMC arms of adult males with SCI and able-bodied controls using the arm LM as a mediator variable. Thirty able-bodied men and thirty men with SCI participated. BMC and BMD were analysed by DXA, and indirect calorimetry was used to calculate VO_2peak during a progressive arm-cranking test. When groups were divided by the amount of LM, the subgroup with highest LM had significantly higher arm BMC compared to the lowest LM subgroup (p ≤ 0.05) in both SCI and able-bodied groups. Moreover, same differences were found when confidence intervals were analysed. Only in the SCI group, arm LM mediated the relationship between bone mass and CRF at 30.9%, as indicated by the Sobel test (z = 2.17 and z = 2.04 for BMC and BMD, respectively). In conclusion, LM mediates the indirect association between CRF and bone health, specifically in the arms. This finding highlights the importance of having an adequate CRF for the maintenance of good bone health in SCI men.     

The Significance of Scientific Capital in UK Medical Education

For decades, debates over medical curriculum reform have centred on the role of science in medical education, but the meaning of ‘science’ in this domain is vague and the persistence of the debate has not been explained. Following Bourdieu, this paper examines struggles over legitimate knowledge and the forms of capital associated with science in contemporary UK medical education. Data are presented from a study of two UK medical schools, one with a traditional, science-oriented curriculum, another with an integrated curriculum. Constructions of legitimate knowledge were explored at both schools through six months participant observation, interviews with faculty members (n=15) and students (n=37) and documentary analysis. Findings show that medical schools compete for both scientific and clinical capital, but ultimately science has greater legitimacy. ‘Science’ is defined in accordance with the structure of the traditional curriculum and has become a symbolic resource – a mark of distinction for both medical schools and medical students – which is equated with clinical competence. The significance of science is circumscribed by the medical education field, yet the struggles for scientific capital there have ramifications beyond medical education itself. It is argued that Bourdieu’s concepts are particularly useful tools for studying the meanings that science takes on outside of the scientific field.