Aversive parenting in China: associations with child physical and relational aggression

This study assessed the combined and differential contributions of Chinese mothers and fathers (in terms of spouse-reported physically coercive and psychologically controlling parenting) to the development of peer-reported physical and relational aggression in their preschool-age children (mean age of 5 years). Results of the two-group (boys and girls) latent sum and difference structural equation model showed that combined parenting effects were slightly more prevalent than differential effects in predicting aggression. Furthermore, physical coercion was predictive of aggression in boys whereas psychological control was primarily associated with aggression in girls. Findings extend our understanding of relational aggression and the meaning of aversive parenting, particularly within the Chinese cultural context.     

Peak muscle activation, joint kinematics, and kinetics during elliptical and stepping movement pattern on a Precor Adaptive Motion Trainer

Kinematic, kinetic, and electromyography data were collected from the biceps femoris, rectus femoris (RF), gluteus maximus, and erector spinae (ES) during a step and elliptical exercise at a standardized workload with no hand use. Findings depicted 95% greater ankle plantar flexion (p = .01), 29% more knee extension (p = .003), 101% higher peak knee flexor moments (p < .001) 54% greater hip extensor moments (p < .001), 268% greater anterior joint reaction force (p = .009), 37% more RF activation (p < .001), and 200 % more ES activation (p <. 001) for the elliptical motion. Sixteen percent more hip flexion (p < .001), 42% higher knee extensor moments (p < .001), and 54% greater hip flexor moments (p = .041) occurred during the step motion. Biomechanical differences between motions should be considered when planning an exercise regimen.     

在教学中对学生创造力的培养

在教学中对学生创造能力的培养,可从以下几方面进行探索。一、设置问题情景设置问题情景,激发学习兴趣和创造欲望,启发学生提出问题（或感受问题）,提出假说,检验假说,发表认识成果,开展创造性教学。创设好的问题情景能激发学生的好奇心和求知欲。问题情景的创设和...     

Fast bowling arm actions and the illegal delivery law in men's high performance cricket matches

This study investigated the bowling arm kinematics of 21 elite fast bowlers (mean +/- SD; age = 27.8 +/- 3.9 years) while performing in test, tour and one day international matches. Thirty-one of the 34 deliveries analysed exhibited straightening at the elbow joint (straightening min = 3 degrees, max = 22 degrees, mean +/- SD = 9 +/- 5 degrees), which by strict definition in the 2000 laws of cricket made them illegal. Five deliveries from three bowlers exhibited hyperextension of the bowling elbow (19 +/- 5 degrees). When assessed against an arbitrary threshold of 15 degrees for elbow straightening, ball speeds for deliveries above this threshold (39.5 +/- 2.0 m/s) were significantly faster (effect size = 1.4; p = 0.006) than deliveries below it (37.1 +/- 1.4 m/s). When grouped by delivery length, the bouncers and short deliveries recorded more elbow straightening (12 +/- 6.6 degrees) than the good length deliveries (9 +/- 4.4 degrees) and the full deliveries (8 +/- 5.7 degrees), although these were not statistically significant differences. The results of this study support the implementation of a tolerance threshold for assessing the legality of fast bowling actions. Further research is recommended into in-match kinematic modelling, laboratory based assessments of illegal bowling actions, perceptual aspects of bowling actions and remedial methods to reduce elbow straightening in bowling actions.     

Practicing a maximal performance task: a cooperative strategy for muscle activity

The effect of practice on predicting elbow flexion movement time was studied. Participants (N = 18) performed 400 elbow flexion trials to a target in the horizontal plane. The trials were distributed equally over four sessions. The goal was to decrease the movement time (MT) for the same degree of accuracy. The electromyographic (EMG) activity of the biceps and triceps brachii was monitored with standard Beckman Ag/AgCl surface electrodes. The EMG measures formed two variable sets within one prediction equation. One variable set was composed of the onset of muscle activity relative to the start of movement (motor time) and the duration of muscle activity. The other variable set consisted of the mean amplitude value of the entire burst and of the first 30 ms (Q30) of activity. As the maximal speed of limb movement increased, the duration of muscle activity (motor time and EMG duration) decreased, and the magnitude of muscle activity (MAV and Q30) increased. Most of the change in the duration of muscle activity occurred in Session 1, while the magnitude of muscle activity continued to increase until Session 3. Multiple regression analysis revealed a cooperative strategy between the magnitude and duration of muscle activity. Early in learning, participants adjusted the magnitude of muscle activity to increase limb movement speed. As practice continued, alterations in the duration of muscle activity became more important, while the magnitude changes were less involved. Late in learning, both dimensions of muscle activity were used to decrease MT. We suggest that the interplay between the magnitude and duration of muscle activity may be due to: (a) cognitive factors related to the division of attention in a motor skill, (b) an increase in the frequency of motor unit firing that affects both dimensions of muscle activity, or (c) some combination of (a) and (b).     

Information needs of United Kingdom primary care clinicians

BACKGROUND: The scope of primary care makes knowledge management in this context very challenging, especially as access to information increases and the role of primary care within the NHS expands. OBJECTIVES: This paper reviews the literature on the information needs of primary care clinicians to enable evidence-based decision making. Drawing on the literature, and using a specific example of a clinical informaticist service, some lessons are drawn on the role of information professionals in facilitating evidence-based health care. METHODS: Literature review. Case study of clinical informaticist service. CONCLUSIONS: There are numerous barriers to clinicians engaging with evidence-based practice. However, providing evidence-based information to clinicians' questions in a user-friendly format has the potential to facilitate changes in practice. The successful implementation of information services requires attention to both academic and service dimensions, fostering closer working relationships between clinicians and information professionals.     

Personal and clinical exercise-related attitudes and behaviors of freshmen U.S. medical students

To determine personal and clinical exercise-related attitudes and behaviors of freshmen U.S. medical students, we surveyed 1,906 entering freshman medical students (response rate = 87%; average age = 24 years) in 17 U.S. medical schools. Students reported a median of 45 min/day of exercise, 80 min/week each of mild and moderate exercise, and 100 min/week of strenuous exercise. Nearly all students (97.6%) engaged in some moderate or vigorous exercise in a typical week. Sixty-four percent complied with U.S. Department of Health and Human Services exercise recommendations. Most freshmen (79%) believed it would be highly relevant to their future practices to counsel patients about exercise; predictors included intention to provide primary care, excellent health, prevention emphasis by their personal physician, and performing more strenuous exercise.