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Identifying factors related to physical activity levels in young people is important for a more efficient health promotion. The aims of this study were to assess physical activity levels in a national sample of urban Spanish adolescents, and to examine the association between significant others' physical activity (father, mother, brother, sister, and close friends) and that of the adolescents. The present study comprised 2260 adolescents (1157 boys, 1103 girls) aged 13.0-18.5 years participating in the AVENA Study. Both the adolescents' physical activity and that of their relatives and close friends was assessed by questionnaire. The odds of being active were higher in boys than girls (odds ratio?=?2.79, 95% confidence interval?=?2.34-3.33) and tended to decrease across age groups in both boys and girls. Father's and older brother's physical activity was associated with boys' physical activity, while that of any significant other was associated with girls' physical activity. When both parents reported being active, boys had nearly two times higher odds of being active and girls had nearly three times higher odds of being active. The physical activity levels of Spanish adolescents are in line with those previously reported. Physical activity levels in girls are strongly related to the physical activity of any significant other, whereas physical activity levels in boys are only related to their male relatives' physical activity.  相似文献   
84.
A broad range of microfluidic applications, ranging from cell culture to protein crystallization, requires multilevel devices with different heights and feature sizes (from micrometers to millimeters). While state-of-the-art direct-writing techniques have been developed for creating complex three-dimensional shapes, replication molding from a multilevel template is still the preferred method for fast prototyping of microfluidic devices in the laboratory. Here, we report on a "dry and wet hybrid" technique to fabricate multilevel replication molds by combining SU-8 lithography with a dry film resist (Ordyl). We show that the two lithography protocols are chemically compatible with each other. Finally, we demonstrate the hybrid technique in two different microfluidic applications: (1) a neuron culture device with compartmentalization of different elements of a neuron and (2) a two-phase (gas-liquid) global micromixer for fast mixing of a small amount of a viscous liquid into a larger volume of a less viscous liquid.  相似文献   
85.
Abstract

In taekwondo, the stance position can potentially affect kick performance. The aim of this study was to analyse mechanical variables in the roundhouse kick in taekwondo according to three stance positions (0°, 45°, 90°). Nine experienced taekwondo athletes performed consecutive kicking trials in a random order according to these three relative positions of the feet on the ground. Measurements for the mechanical analysis were performed using two 3D force plates and an eight-camera motion capture system. The taekwondo athletes’ reaction and execution times were shorter when starting from the 0° and 45° stance positions than from the 90° position (P < 0.05). Moreover, the ground reaction force was negatively correlated with execution time and positively with velocity of thigh and shank. Our results suggest that the stance position affects the execution technique of taekwondo athletes’ kicks. It is suggested that athletes should not adopt the 90° stance position because it will not enable them to achieve the best performance in the roundhouse kick.  相似文献   
86.
The winner’s curse is a well-known phenomenon in the auction theory. The main aim of this article is to verify its existence in football broadcasting rights. The underlying objective is to assess whether some indices of this situation are verified and can cause a winner’s curse. The methodology is based on the application of Andreff (2014 Andreff, Wladimir. 2014. “The Winner’s Curse in Sports Economics.” Contemporary Research in Sports Economics 14: 177205. [Google Scholar])’s six indices and a seventh index (disappointment) to the domestic markets for broadcasting rights of the French and English football leagues. These two markets have seen an increase in the number of packages offered to broadcasters, with the possibility of several ‘winners’. The article shows that the winner of the major packages in the auction is not cursed. The curse is more likely to happen for the second mover. As such, the article suggests a practical recommendation for broadcasters interested in football rights: win the best package or keep away.  相似文献   
87.
Aims: Exercise combined with adipose tissue lipolytic inhibition augments intramuscular lipid and glycogen use in type 2 diabetes patients. The present study investigates the impact of adipose tissue lipolytic inhibition during exercise on subsequent postprandial glycemic control in type 2 diabetes patients.

Methods: Fourteen male type 2 diabetes patients (age 65?±?2 years, HbA1c 6.7?±?0.1% (50?±?2?mmol/mol)) participated in a double-blind placebo-controlled randomized cross-over study in which subjects performed endurance-type exercise after being administered 250?mg of a nicotinic acid analogue (acipimox; ACP) or a placebo (PLA). A control experiment was included in which no exercise was performed (CON).

Results: Sixty minutes of endurance-type exercise (at 45% Wpeak) did not significantly lower circulating plasma glucose and insulin excursions in PLA when compared with CON (P?=?.300). Acipimox administration strongly reduced circulating plasma FFA concentrations during exercise (P?i.e. postprandial) in ACP when compared with either CON (P?=?.041 and P?=?.002, respectively) or PLA (P?=?.009 and P?=?.001, respectively).

Conclusions: Collectively, exercise with adipose tissue lipolytic inhibition reduces postprandial blood glucose and insulin excursions and, as such, further improves glycemic control in male type 2 diabetes patients.  相似文献   
88.
ABSTRACT

This study aimed at evaluating the effects of mental and muscle fatigue on table tennis performance. Mental fatigue (MF) was induced by completion of 90 minutes of the AX-CPT; muscle fatigue was induced by completion of an eccentric exercise performed with the elbow flexors (biceps fatigue, BF) or the knee extensors (quadriceps fatigue, QF). The control condition consisted of watching a movie. Stroke parameters (speed and accuracy of the ball), as well as feelings of fatigue and force production capacity of the elbow flexors (BF, MF and control conditions) and knee extensors (QF condition), were assessed pre and post fatigue protocols. Feelings of fatigue increased post fatigue protocols. Force production capacity decreased only in the BF and QF conditions. BF and MF induced a decrease in accuracy. This decrease in accuracy was associated with an increased ball speed in the BF condition, and a decreased ball speed in the MF condition. QF had a negligible effect on stroke performance. Our results suggest that both mental fatigue, and muscle fatigue, significantly impair table tennis performance and therefore coaches should take into account both the physical and mental state of table tennis players to optimize performance.  相似文献   
89.
A mail survey of 333 American universities was conducted to assess the current status of Student Evaluation of Instruction. Based on a 68% return, it was concluded that there has been an increase in the popularity of student ratings as a means of evaluating faculty performance, as well as an increase in the frequency with which evaluation results are used in decisions concerning faculty status. However, at most universities, research on the rating instruments does not seem to have kept pace with the decisions that are based on the rating instruments.  相似文献   
90.
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