Cognitive social learning mediators of aggression

This research explored links between aggression in elementary school children and 2 classes of social cognitions that might influence children's decisions about whether to behave aggressively. Aggressive and nonaggressive children (mean age 11.3 years) responded to 2 questionnaires. One questionnaire measured children's perceptions of their abilities to perform aggression and related behaviors (perceptions of self-efficacy), and the other measured children's beliefs about the reinforcing and punishing consequences of aggression (response-outcome expectancies). Compared to nonaggressive children, aggressive subjects reported that it is easier to perform aggression and more difficult to inhibit aggressive impulses. Aggressive children also were more confident that aggression would produce tangible rewards and would reduce aversive treatment by others. There were negligible sex differences in perceived self-efficacy for aggression but large sex differences in anticipated social and personal consequences for aggression, with girls expecting aggression to cause more suffering in the victim and to be punished more severely by the peer group and by the self. It was concluded that children's knowledge of their capabilities and children's knowledge of the consequences of their actions are factors that need to be taken into account by cognitive models of aggression.     

Measurement of badminton racket deflection during a stroke

The compliance of a badminton racket is an important design consideration, which can be better understood by studying the deflection behaviour of the racket during a stroke. Deflection can be measured using direct methods, such as motion capture or high speed video, or by indirect methods, which then require a mathematical model in order to calculate the deflections from indirect measures. Indirect methods include strain gauges and accelerometers. Here, racket deflection is measured directly using motion capture and compared with deflections calculated from strain gauge data using a beam model. While the elastic behaviour is better calculated from strains than measured by motion capture, it is not possible to extract the whole motion of the racket from strain data. Motion capture is therefore also necessary to determine the rigid body velocity, in order to put the elastic velocity (as calculated from strains) in perspective.     

Decrease in pulmonary diffusion capacity after maximal exercise

Oppression of the chest, cough and orthopnea are well known to occur in some athletes after competitions, maybe reflecting an increase in lung water. In order to indicate if lung water increases after maximal exercise we measured pulmonary diffusion capacity before and 2.1 h after a short maximal arm exercise bout in 11 canoeists and showed a decrease of 6.7%. The result may be explained by a calculated 17% increase in alveolar interstitial volume.