On the application of distribution theory to variational problems

The fixed end-point problem in variational calculus for an extremal containing corners is considered in a distributional context. The distributional Euler equation obtained is valid over the entire extremal and implicitly contains the Weierstrass-Erdmann corner conditions.     

A comparison of the physiological response to simulated altitude exposure and r-HuEpo administration

Concerns have been raised about the morality of using simulated altitude facilities in an attempt to improve athletic performance. One assumption that has been influential in this debate is the belief that altitude houses simply mimic the physiological effects of illegal recombinant human erythropoietin (r-HuEpo) doping. To test the validity of this assumption, the haematological and physiological responses of 23 well-trained athletes exposed to a simulated altitude of 2650-3000 m for 11-23 nights were contrasted with those of healthy volunteers receiving a low dose (150 IU·kg^-1 per week) of r-HuEpo for 25 days. Serial blood samples were analysed for serum erythropoietin and percent reticulocytes; maximal oxygen uptake ([Vdot]O_2max) was assessed before and after r-HuEpo administration or simulated altitude exposure. The group mean increase in serum erythropoietin (422% for r-HuEpo vs 59% for simulated altitude), percent reticulocytes (89% vs 30%) and [Vdot]O_2max (6.6% vs -2.0%) indicated that simulated altitude did not induce the changes obtained with r-HuEpo administration. Based on the disparity of these responses, we conclude that simulated altitude facilities should not be considered unethical based solely on the tenet that they provide an alternative means of obtaining the benefits sought by illegal r-HuEpo doping.     

American Association for Health,Physical Education,and Recreation

Abstract

Utilizing canonical correlation analysis, the multivariate relationship between selected measures of motor performance and intellectual achievement was studied on 91 high school pupils. The students involved in the study were culturally deprived students who had been achieving well below their expected capacity. A significant relationship was found between the intellectual achievement domain and the motor performance domain. Also, significant relationships were found between the intellectual achievement domain and both of the sub-domains of fitness and coordination. The results in the present investigation were compared with the univariate analyses in a previous study. It was concluded that when the degree of relationship between two domains is desired, canonical correlation analysis may be of more value than the usual univariate procedures.     

戈尔呼吁美国“为人类迈进一大步”

有人把全球变暖与反恐战争相提并论,认为人类前景的好坏取决于是否赢得这场反全球变暖战争。而美国是温室气体排放的第一大国。统计资料显示,2004年全球排放的265亿吨二氧化碳中,美国占22.1%。但布什政府2001年以经济、就业为由,退出《京都议定书》,此后一直拒绝出台政策限制温室气体排放。把将要承担的任务与登月作比较,诺贝尔奖得主、美国前副总统戈尔敦促国家承担起应对气候变化的义务:在十年内生产100%的可再生清洁能源。     

A promising route to neuromorphic vision

The human vision system has a very strong capability in perceiving surround-ings.Such visual perception starts in the retina,which receives and preprocesses the...