关于风险投资者和投资管理机构的关系模型

由于信息不对称，风险投资管理机构存在很大的道德风险。本文通过风险投资者和投资管理机构之间的关系研究认为，使投资管理者的回报和基金收益挂钩和公布投资管理者的业绩信息，可以对投资管理者进行有效的激励和约束。     

The dyadic nature of bullying and victimization: testing a dual-perspective theory

For this study, information on Who Bullies Who was collected from 54 school classes with 918 children (M age = 11) and 13,606 dyadic relations. Bullying and victimization were viewed separately from the point of view of the bully and the victim. The two perspectives were highly complementary. The probability of a bully-victim relationship was higher if the bully was more dominant than the victim, and if the victim was more vulnerable than the bully and more rejected by the class. In a bully-victim dyad, boys were more often the bullies. There was no finding of sex effect for victimization. Liking reduced and disliking increased the probability of a bully-victim relationship.     

Barriers to prisoner participation in educational courses: Insights from a remand prison in Belgium

International Review of Education - This article examines the profile of prisoners who do not take part in formal education while being incarcerated (e.g. language or ICT courses) and the barriers...     

Refining Students’ Explanations of an Unfamiliar Physical Phenomenon-Microscopic Friction

Research in Science Education - The first phase of this multiphase study involves modeling of college students’ thinking of friction at the microscopic level. Diagnostic interviews were...     

The evidence for the impact of policy on physical activity outcomes within the school setting: A systematic review

BackgroundDespite the well-established health benefits of physical activity (PA) for young people (aged 4–19 years), most do not meet PA guidelines. Policies that support PA in schools may be promising, but their impact on PA behavior is poorly understood. The aim of this systematic review was to ascertain the level and type of evidence reported in the international scientific literature for policies within the school setting that contribute directly or indirectly to increasing PA.MethodsThis systematic review is compliant with Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Six databases were searched using key concepts of policy, school, evaluation, and PA. Following title and abstract screening of 2323 studies, 25 progressed to data synthesis. Methodological quality was assessed using standardized tools, and the strength of the evidence of policy impact was described based on pre-determined codes: positive, negative, inconclusive, or untested statistically.ResultsEvidence emerged for 9 policy areas that had a direct or indirect effect on PA within the school setting. These were whole school PA policy, physical education, sport/extracurricular PA, classroom-based PA, active breaks/recess, physical environment, shared use agreements, active school transport, and surveillance. The bulk of the evidence was significantly positive (54%), 27% was inconclusive, 9% was significantly negative, and 11% was untested (due to rounding, some numbers add to 99% or 101%). Frequency of evidence was highest in the primary setting (41%), 34% in the secondary setting, and 24% in primary/secondary combined school settings. By policy area, frequency of evidence was highest for sport/extracurricular PA (35%), 17% for physical education, and 12% for whole school PA policy, with evidence for shared use agreements between schools and local communities rarely reported (2%). Comparing relative strength of evidence, the evidence for shared use agreements, though sparse, was 100% positive, while 60% of the evidence for whole school PA policy, 59% of the evidence for sport/extracurricular PA, 57% of the evidence for physical education, 50% of the evidence for PA in classroom, and 50% of the evidence for active breaks/recess were positive.ConclusionThe current evidence base supports the effectiveness of PA policy actions within the school setting but cautions against a “one-size-fits-all” approach and emphasizes the need to examine policy implementation to maximize translation into practice. Greater clarity regarding terminology, measurement, and methods for evaluation of policy interventions is needed.     

Pedometer-determined physical activity and its comparison with the International Physical Activity Questionnaire in a sample of Belgian adults

Pedometer-determined physical activity (PA) levels in Belgian adults were provided and compared to PA scores reported in the International Physical Activity Questionnaire (IPAQ). The representative sample (N=1239) of the Belgian population took on average 9655 (4526) steps/day. According to pedometer indices 58.4% were insufficiently active. Steps/day differed significantly between gender (F = 5.0, p = .026), age groups (F = 3.3, p = .01), employment status (F = 6.2, p = .013), and days of monitoring (F = 7.4, p = .007). Steps/day were negatively correlated to the time spent sitting and positively to PA at work, in transport, and in leisure time (p < .001). Steps data can discriminate between PA levels reported in the IPAQ. Belgian population pedometer-determined PA levels are higher than those reported in samples of the United States; however, there is a wide distribution of ambulatory behavior     

Optimized versus corrected peak power during friction-braked cycle ergometry in males and females

The aim of this study was to compare optimization and correction procedures for the determination of peak power output during friction-loaded cycle ergometry. Ten male and 10 female sports students each performed five 10-s sprints from a stationary start on a Monark 864 basket-loaded ergometer. Resistive loads of 5.0, 6.5, 8.0, 9.5, and 11.0% body weight were administered in a counterbalanced order, with a recovery period of 10 min between sprints. Peak power was greater and occurred earlier, with less work having been done before the attainment of peak power, when the data were corrected to account for the inertial and frictional characteristics of the ergometer. Corrected peak power was independent of resistive load (P > 0.05), whereas uncorrected peak power varied as a quadratic function of load (P < 0.001). For males and females, optimized peak power (971 +/- 122 and 668 +/- 37 W) was lower (P < 0.01) than either the highest (1074 +/- 111 and 754 +/- 56 W respectively) or the mean (1007 +/- 125 and 701 +/- 45 W respectively) of the five values for corrected peak power. Optimized and mean corrected peak power were highly correlated both in males (r = 0.97, P < 0.001) and females (r = 0.96, P < 0.001). The difference between optimized and mean corrected peak power was 37 +/- 30 W in males and 33 +/- 14 W in females, of which approximately 15 W was due to the correction for frictional losses. We conclude that corrected peak power is independent of resistive load in males and females.     

Effects of blood flow restriction without additional exercise on strength reductions and muscular atrophy following immobilization:A systematic review

Purpose:To investigate whether blood flow restriction(BFR) without concomitant exercise mitigated strength reduction and atrophy of thigh muscles in subjects under immobilization for lower limbs.Methods:The following databases were searched:PubMed,CINAHL,PEDro,Web of Science,Central,and Scopus.Results:The search identified 3 eligible studies,and the total sample in the identified studies consisted of 38 participants.Isokinetic and isometric torque of the knee flexors and extensors was examined in 2 studies.Cross-sectional area of thigh muscles was evaluated in 1 study,and thigh girth was measured in 2 studies.The BFR protocol was 5 sets of 5 min of occlusion and 3 min of free flow,twice daily for approximately 2 weeks.As a whole,the included studies indicate that BFR without exercise is able to minimize strength reduction and muscular atrophy after immobilization.It is crucial to emphasize,however,that the included studies showed a high risk of bias,especially regarding allocation concealment,blinding of outcome assessment,intention-to-treat analyses,and group similarity at baseline.Conclusion:Although potentially useful,the high risk of bias presented by original stodies limits the indication of BFR without concomitant exercise as an effective countermeasure against strength reduction and atrophy mediated by immobilization.     

中国区域经济与环境协调度预测分析

经济发展与环境之间的关系已经成为全世界特别是发展中国家关心的问题，但有关的定量研究比较缺乏。该文首先解释了经济与环境协调度基本概念与模型内涵，并介绍了灰色系统在贫信息系统中进行预测的基本原理。通过灰色系统GM(1,1)模型对90年代我国省级区域的经济与环境协调度进行了计算，经过检验，模型模拟精度较高。因此运用此模型对2005年与2010年的区域协调度进行了预测。结果表明，我国大部分地区的经济与环境关系基本处于调和状态，即经济的增长是以牺牲环境为代价的。未来10a的协调度空间分布仍然呈现“U”型特征。处于转折点附近的省区协调度波动比较大，包括广大的中部地区。尽量减少波动并尽快实现协调度的转折是这些地区在经济发展过程中要注意的问题；西部大部分地区如果继续沿用90年代的发展策略，对经济发展政策和手段不作宏观的调控，在西部开发过程中出现的环境问题将会越来越严重。     

生态因子对礁膜配子放散及黑暗时间对合子固着的影响

采用单因子实验方法研究了湛江港礁膜配子的成熟放散与温度、光照、比重和pH值的关系,并对黑暗时间对配子接合及合子附着的影响进行了初步研究。实验结果表明,在温度为20℃、光照强度为80．13μmol/（m^2·s）左右、pH值为7．9、比重为1．018的室内培养条件下,为礁膜配子体成熟和配子囊大量放散配子的最适宜生态条件。早期合子附着的适宜黑暗时间为5—6h。