终极娱乐——给魔术师和心灵魔术师的导演笔记（节选）

第二章神秘娱乐的层次关系 从我们的这边看出去,我们带给观众的表演是魔术效果（effect）。而从观众的角度来看呢,我们的演出可分成三种不同的感受：     

Beyond sensation seeking: affect regulation as a framework for predicting risk-taking behaviors in high-risk sport

Sensation seeking has been widely studied when investigating individual differences in the propensity for taking risks. However, risk taking can serve many different goals beyond the simple management of physiological arousal. The present study is an investigation of affect self-regulation as a predictor of risk-taking behaviors in high-risk sport. Risk-taking behaviors, negative affectivity, escape self-awareness strategy, and sensation seeking data were obtained from 265 high-risk sportsmen. Moderated hierarchical regression analysis revealed significant main and interaction effects of negative affectivity and escape self-awareness strategy in predicting risk-taking behaviors: high-risk sportsmen's negative affectivity leads them to adopt risk-taking behaviors only if they also use escape self-awareness strategy. Furthermore, the affective model remained significant when controlling for sensation seeking. The present study contributes to an in-depth understanding of risk taking in high-risk sport.     

Extra-curricular participation in sports and socio-demographic factors in Spanish adolescents: the AVENA study

The aims of this study were to identify differences between the sexes in extra-curricular participation in sports and to determine its association with body fat and socio-demographic factors in Spanish adolescents. A total of 2165 adolescents (1124 males and 1041 females) aged 13.0-18.5 years from the AVENA Study participated. Participants filled in an ad hoc questionnaire for extra-curricular participation in sports, which was the dependent variable. Independent variables were: age, percent body fat, and father's and mother's educational level and occupation. Chi-square tests and logistic regression were applied. Bivariate analysis showed for male adolescents that age and father's occupation were related to extra-curricular participation in sports. In addition, body fat and mother's education and occupation (all P?相似文献   

Effect of countermovement on elbow joint extension power-load characteristics

The aim of the present study was to examine elbow joint extension power-load characteristics with and without a countermovement. Eight male participants performed maximal elbow extensions with and without a countermovement against different loads (0, 2.5, 5.0, 7.5, 10.0, 12.5, and 15.0 kg). Electromyographic activity of the lateral and long heads of the triceps brachii and the biceps brachii muscles was recorded. The average joint power in the concentric phase was significantly enhanced in the countermovement condition at all loads except for 0 kg. The optimal load for the maximal joint power was greater in the countermovement (7.5 kg) than in the no countermovement condition (5.0 kg). Electromyographic activity was unchanged over the intensities and conditions. Our results suggest that the optimal load for the maximal joint power depends on the type of action (i.e. with or without a counter-movement), and that the enhanced joint power in the countermovement condition is due primarily to the storage and utilization of elastic energy.     

Kinematic differences of elite and high-performance tennis players in the cross court and down the line forehand

This study identified and compared the full body kinematics of different skill levels in the forehand groundstroke when balls were hit cross court and down the line. Forty-three three-dimensional retroreflective marker trajectories of six elite and seven high-performance players were recorded using an eight-camera 400 Hz, Vicon motion analysis system. The six highest horizontal velocity forehands with reliable kinematics of all participants were analysed for each specific situation (a total of 156 analysed shots). Significant differences (p < 0.01) and large effect sizes were observed between elite and high-performance players in linear velocity of the shoulder (2.0 vs. 1.2 m/s), angular velocity of the pelvis (295 vs. 168 degrees/s), and angular velocity of the upper trunk (453 vs. 292 degrees/s) at impact. The elite group showed a tendency towards higher racquet velocities at impact (p < 0.05). No significant differences were found in angular displacement of the racquet, hip alignment, or shoulder alignment at the completion of the backswing; nor did angular displacement vary significantly at impact. Irrespective of the group, different shoulder, hip, and racquet angles were found at impact, depending on the situation. The results should assist coaches when striving to improve their players' forehand.     

Modifiable futures: science fiction at the bench

Science fiction remains an alien dimension of the history of science. Historical and literary studies of science have become increasingly attentive to various "literary technologies" in scientific practice, the metaphorical features of scientific discourse, and the impact of popular science writing on the social development of scientific knowledge. But the function of science fiction and even literature as such in the history of scientific and technological innovation has often been obscured, misconstrued, or repudiated owing to conventional notions of authorship, influence, and the organic unity of texts. The better to address those close encounters where scientific practice makes use of speculative fiction, this essay proposes that we instead analyze such exchanges as processes of appropriation, remixing, and modification.     

Three Cases of Lead Toxicity Associated with Consumption of Ayurvedic Medicines

Ayurveda is a traditional form of medicine used by majority of the Indians. Here we report three cases of lead toxicity, following intake of Ayurvedic medicines. Three patients presented with blood lead levels (BLLs) of 122.4, 115 and 42.8 μg/dl respectively at the time of hospitalization. The first case was chelated with D- penicillamine, the second with calcium disodium ethylene diamino tetra acetate (EDTA) and the third with environmental intervention and education. Associated Ayurvedic products were collected from patients and analyzed for metallic concentration. Cessation of Ayurvedic medication along with chelation, nutritional intervention and education, reduced the BLL to 27.4 μg/dl in the first case after 1 year, 21.1 μg/dl after 9 months in the second and 18.2 μg/dl after 6 months in the third case.     

Does Chewing Coca Leaves Influence Physiology at High Altitude?

Andean Indians have used coca leaves (Erythroxylon coca and related species) for centuries to enhance physical performance. The benefits and disadvantages of using coca leaf have been a subject of many political debates. The aim of this study was to investigate the effects of chewing coca leaves on biochemical and physiological parameters. Cutaneous microdialysis catheters were used to estimate systemic biochemical changes. We subjected 10 healthy adult males (local residents) in Cajamarca (Peru, altitude 2700 m) to a standardised exercise routine on a stationary cycle ergometer. The blood pressure, oxygen saturation (digital), pulse, VO2 max and ECG (Holter monitor) were recorded before the exercise. Cutaneous microdialysis catheters were introduced in the forearm. The subjects were given to chew 8 g of coca leaves with a small amount of lime. They were then placed on the cycle ergometer for 20 min. Blood pressure, oxygen saturation, pulse, ECG and VO2 max were recorded. Pyruvate, glucose, lactate, glycerol and glutamate levels were estimated. Oxygen saturation, blood pressure, and pulse rate did not show any significant changes between the two groups. Glucose levels showed hyperglycaemic response. Glycerol, Lactate and Pyruvate increased. Glutamate remained unchanged. Similar changes were not seen in the controls. These results suggest that coca leaves have blocked the glycolytic pathway of glucose oxidation resulting in accumulation of glucose and pyruvate. The energy requirement for exercise is being met with beta-oxidation of fatty acids. The glycerol released was also getting accumulated since its pathway for oxidation was blocked. These experimental findings suggest that chewing coca leaves is beneficial during exercise and that the effects are felt over a prolonged period of sustained physical activity.     

创造奇迹的人

福泽林盖从不相信＂奇迹＂。但在他坚决否认这个世界有奇迹的时候,他发现自己就能创造奇迹。那是一个停电的夜晚,他当时正与他的朋友托德·比米什在一家酒吧喝酒。