A comparison of modelling and imagery in the acquisition and retention of motor skills

Although many researchers have examined the effects of imagery and/or modelling interventions, it is unclear which of the two interventions is more effective. In two experiments, novice learners assessed over multiple trials of a free weight squat lifting or a stabilometer balancing task were given modelling, imagery, a combination of modelling and imagery, or control interventions. Group differences indicated, in general, that groups receiving modelling (modelling, combination) evidenced a more appropriate form than groups that did not receive modelling (imagery, control). When apparent, these differences were already in place after the first of several interventions. Practical implications are that even a single bout of modelling can have immediate beneficial effects on movement form (Experiments 1 and 2) and outcome (Experiment 1).     

网络技术:改进数据访问的性能

谈起网格,肯定要涉及数据、信息以及如何在分布式的基础设施上对二者进行智能化处理.而这个时候似乎更让大家着迷的是网格的计算能力,而数据在以计算为重点的网格中仅能占据次席.     

Failure of caffeine to affect metabolism during 60 min submaximal exercise

Caffeine consumption prior to athletic performance has become commonplace. The usual dosage is approximately 200 mg, a level of caffeine ingestion equivalent to two cups of brewed coffee. This study was designed to examine the effects of a common level of caffeine ingestion, specifically 200 mg, on metabolism during submaximal exercise performance in five males. The subjects performed two 60-min monitored treadmill workouts at 60% maximal heart rate during a 2-week period. The subjects were randomly assigned, double-blind to receive a caffeine or placebo capsule 60 min prior to exercise. Testing was performed in the afternoon following a midnight fast. Venous blood was withdrawn pre-exercise, every 15 min during the workout, and 10 min after recovery. Blood was analysed for free fatty acid, triglycerides, glucose, lactic acid, haemoglobin and haematocrit. The respiratory exchange ratio (R), perceived exertion (RPE) and oxygen uptake were measured every 4 min during exercise. An examination of the data with repeated-measures ANOVA revealed no significant differences between the two groups. Within the limitations of the study, it was concluded that 200 mg caffeine failed to affect metabolism during 60 min submaximal exercise.     

Is it wrong to play violent video games?

Many people have a strong intuition that there is something morallyobjectionable about playing violent video games, particularly withincreases in the number of people who are playing them and the games'alleged contribution to some highly publicized crimes. In this paper,I use the framework of utilitarian, deontological, and virtue ethicaltheories to analyze the possibility that there might be some philosophicalfoundation for these intuitions. I raise the broader question of whetheror not participating in authentic simulations of immoral acts in generalis wrong. I argue that neither the utilitarian, nor the Kantian hassubstantial objections to violent game playing, although they offersome important insights into playing games in general and what it ismorally to be a ``good sport.' The Aristotelian, however, has a plausibleand intuitive way to protest participation in authentic simulations ofviolent acts in terms of character: engaging in simulated immoral actserodes one's character and makes it more difficult for one to live afulfilled eudaimonic life.     

Individual Differences in the Stability and Change of Childhood Depression: A Growth Mixture Model With Structured Residuals

Studies of developmental trajectories of depression are important for understanding depression etiology. Existing studies have been limited by short time frames and no studies have explored a key factor: differential patterns of responding to life events. This article introduces a novel analytic technique, growth mixture modeling with structured residuals, to examine the course of youth depression in a large, prospective cohort (N = 11,641, ages 4–16.5, 96% White). Age-specific critical points were identified at ages 8 and 13 where depression symptoms spiked for a minority of children. Most depression risk was due to dynamic responses to environmental events, drawn not from a small pool of persistently depressed children, but a larger pool of children who varied across higher and lower symptom levels.     

Psychology,market pressures,and pricing decisions in higher education: the case of the US private sector

Higher Education - We examine listed tuition and institutional aid practices within the US private sector, a sector where market pressures are relatively strong and consequently influence...     

Validity Evidence of an Electronic Portfolio for Preservice Teachers

This study applied Messick's unified, multifaceted concept of construct validity to an electronic portfolio system used in a teacher education program. The subjects included 128 preservice teachers who recently completed their final portfolio reviews and student teaching experiences. Four of Messick's six facets of validity were investigated for the portfolio in this study, along with a discussion of the remaining facets examined in two previous studies. The evidence provided support for the substantive and generalizability aspects of validity, and limited support for the content, structural, external, and consequential aspects of validity. It was suggested that the electronic portfolio may be used as one requirement for certification purposes, but may not be valid for the purpose of assessing teacher competencies .