门静脉血流改变对晚期高位胆管癌的诊断价值

通过探讨正常人与高位胆管癌病人之间的门静脉血流改变,发现两者之间有明显的不同。所以门静脉血流改变在诊断高位胆管癌方面具有重要意义。     

Blood pressure reactivity to active and passive behavioral conditions in hypertensives and normotensives

Blood pressure reactivity and passive behavioral tasks was studied in patients with mild essential hypertension and normotensive controls. The passive condition included 10 presentations of a 6 sec, 78 dB, 1000 Hz tone without any response requirements. In the active condition subjects were given an additional 10 tone presentations and asked to press a push-button at tone termination. The absolute and percent increase in systolic blood pressure from rest was greater in hypertensives than normotensives in response to the active condition but similar to the passive condition. It is concluded that patients with hypertension compared to normotensive controls show exaggerated blood pressure reactivity to tasks involving active but not passive coping efforts. Since the tasks used to induce active and passive coping in the present study were identical apart from coping requirements, the notion that the activity dimension in and of itself modulates reactivity differences between patients and controls is supported.     

The causal impacts of empty stadiums on women’s sports activities: Evidence from European football leagues

This paper examines the effect of spectators on women’s football games. COVID-19 and related restrictions provide a unique opportunity with an adequate sample size to test the effect of lockdown on sports activities. Studies have recently exploited this opportunity for men’s football to better understand the potential causes of home advantage and, more specifically, assess the psychological consequences when matches are played without supporters. Despite the increased scientific interest, there was only one paper that focused on women’s football. Therefore, we aim to contribute to this research field by considering matches from four major European women’s football leagues. The findings suggest that for three of these leagues, lockdown has a statistically significant effect on the sanctioned yellow cards by either reducing the number of yellow cards sanctioned to the away teams or increasing the number of yellow cards sanctioned to the home teams. Nonetheless, lockdown does not affect any final match outcomes; therefore, it does not significantly affect the magnitude of home advantage for women’s games.     

The effects of attentional shift training on the execution of soccer skills: A preliminary investigation

One of the most important skills in soccer is the ability to respond quickly and accurately to the changing demands of the competitive environment (i.e., position of ball, teammates, opponents). A multiple baseline design across 4 male collegiate soccer players was used to determine the effectiveness of an attentional training program on the execution of targeted soccer skills. The treatment included information and laboratory attentional shift exercises followed by practice of attentional shifting skills on the execution of different soccer exercises. Following treatment, the accuracy of execution of the experimental soccer drill improved.     

Behavioral coaching in the development of skills in football, gymnastics, and tennis

A review of the literature indicates that methods of skill acquisition based on the operant paradigm have been scientifically validated with many motor behaviors. However, these procedures have been limited to the use of positive reinforcement for correct performance when applied to the acquisition of complex sports skills in natural settings. To find complementary procedures to enhance skill acquisition, a coaching method involving several behavioral techniques was developed that focused on remediation of errors. This coaching method combined the following components: (1) systematic use of verbal instructions and feedback, (2) positive and negative reinforcement, (3) positive practice, and (4) time out. Three sports, football, gymnastics, and tennis, were selected to determine the effectiveness and generality of this behavioral coaching method. A total of 23 male and female subjects, ranging in age from 11 to 35, was included in this study. Baseline data were first collected for each sport under standard coaching conditions. Next, the behavioral coaching method was evaluated depending on the sport in either a multiple baseline or a reversal design. The behavioral dimensions selected were blocking in football; backward walkovers, front hand springs, and reverse kips in gymnastics; and the forehand, backhand, and serve in tennis. Behavioral coaching was immediately effective in increasing the correct execution of complex skills in all three sports. Gains of up to 10 times the baseline performance were achieved in each sport. In football, behavioral coaching resulted in an increase in correct blocking performance from a baseline average of 5% to 51.3%. Gymnasts' performances increased from baseline averages of 2.7% to 52.6% across the three skills. In tennis, standard coaching produced an average of 6% correct performance which increased dramatically under behavioral coaching to 57% across the three strokes. The success of the behavioral coaching package used here suggests that a technology of behavior may offer additional and complementary strategies to the acquisition of motor skills in the natural environment.     

Evaluation of a coaching strategy to reduce swimming stroke errors with beginning age-group swimmers

A coaching strategy to decrease errors in swimming strokes with swimmers who had not improved under "standard" coaching procedures was investigated using a multiple baseline design across subjects and swimming strokes. The procedure resulted in a large decrease in errors on swimming strokes during sessions in a training pool. Stimulus generalization of improved performance to normal practice conditions in the regular pool was observed with all but one swimmer. This improvement was maintained during two maintenance phases lasting approximately 2 weeks, as well as under standard coaching conditions during at least a 2-week follow-up. For two swimmers, error rates on one of the strokes showed a gradual increase between the third and fifth week of follow-up, but brief remedial prompting sessions immediately corrected their performance. Some beneficial response generalization to other components of the stroke being trained was observed, but no improvements were found on untrained strokes. The error correction package did not disrupt practice, require excessive amounts of the coach's time, or necessitate the use of cumbersome apparatus. In addition, the coach and the swimmers considered the procedures to be effective, and expressed their willingness to participate in them again in the future.     

EVALUATION OF BIOFEEDBACK IN THE TREATMENT OF BORDERLINE ESSENTIAL HYPERTENSION1

Direct biofeedback of blood pressure was compared with frontal EMG biofeedback and with self-instructed relaxation for the treatment of essential hypertension in a controlled group outcome study. Patients were followed up for four months after the end of treatment. Generalization of treatment effects was assessed through pre- and posttreatment measurements of blood pressure under clinical conditions in a physician's office. There were no significant reductions in diastolic blood pressure. The systolic blood pressure (SBP) of the patients receiving blood pressure biofeedback decreased 8.1 mm mercury (p = 0.07) and the SBP of the patients in the relaxation condition decreased 9.5 mm mercury (p = 0.05). In the generalization measures, there were significant reductions in SBP for the relaxation group. The results are discussed in terms of the general lack of replicability within the area of biofeedback treatment of hypertension.     

THE ROLE OF FEEDBACK IN VOLUNTARY CONTROL OF BLOOD PRESSURE IN INSTRUCTED SUBJECTS1

Forty normal male volunteers were randomly assigned to one of four experimental conditions and instructed to raise and lower their systolic blood pressure. Subjects received either beat-to-beat feedback contingent on pressure changes, noncontingent beat-to-beat feedback, noncontingent feedback presented randomly with respect to the occurrence of each heart beat, or instructions alone. The order of increase and decrease trial blocks was counterbalanced across groups. Subjects receiving contingent feedback were monetarily rewarded for appropriate pressure changes. Subjects receiving noncontingent feedback received rewards and feedback equal to the mean received by the contingent group. Subjects in the instructions-only condition were also paid this bonus but were informed of their earnings only at the conclusion of the experiment. Results indicated that in the presence of instructions, feedback, whether contingent or noncontingent, added little to subjects' ability to control pressure during a single session. Theoretical and clinical implications are discussed.     

长期高策略性技能训练对运动员大脑白质结构的影响：一项DTI研究

目前关于运动员经验优势的脑机制还存在争议, 尤其对于涉及较多认知过程参与的高策略性技能项目运动员, 其大脑白质结构可塑性变化还需进一步探究。研究横向对比了乒乓球运动员和非运动员大脑白质纤维束的弥散张量成像数据。结果发现, 相比于非运动员, 乒乓球运动员在连接背侧和腹侧通路脑区的双侧皮质脊髓束、左侧上纵束、左侧下纵束和双侧额枕下束的各向异性值(FA)更大, 进一步分析发现, 部分腹侧通路白质纤维束FA增加的原因是径向扩散系数(RD)下降。研究结果支持了动作双通路模型。提示经过长期高策略性技能训练, 乒乓球运动员在背侧和腹侧通路上的白质纤维束结构完整性增强。     

Athlete perspectives on the enablers and barriers to nutritional adherence in high-performance sport

ObjectivesPoor adherence to nutritional guidance by athletes may compromise their health and performance. Enhancing adherence is therefore an important performance and welfare strategy. The aim of this study was to qualitatively explore the barriers and enablers of elite athletes' adherence to nutritional guidelines.DesignUnderpinned by our constructionist epistemological position and our relativist ontology, we conducted a qualitative study using focus groups.MethodsWe used the Capability, Opportunity, and Motivation Behaviour (COM-B) model and the Theoretical Domains Framework (TDF) to conduct focus group discussions with a purposive sample of 39 UK-based funded athletes (mean age = 23 ± 3.81), participating in either Olympic and Paralympic sport (n = 30) or professional sport (n = 9), who had access to a nutritionist. Data were analysed using reflexive thematic analysis.ResultsAthlete adherence to nutritional guidance was seasonal and included inadequate energy intakes and episodes of binge eating. Underpinning these behaviours, athletes' emotional barriers (motivation) are reinforced through their social interactions within the high-performance environment (opportunity) and athletes' training environment limits developmental opportunities for food planning (capability). However, a holistic-developmental approach by the sports nutritionists (opportunity) supports athlete wellbeing and nutritional adherence.ConclusionThese findings advance theoretical understanding of the barriers and enablers of nutritional adherence amongst elite-level athletes in high-performance sport and present a number of significant implications for athlete support personnel seeking to enhance performance in demanding sporting contexts. Drawing on the Behaviour Change Wheel (BCW), recommendations include the need to 1) train and educate sports nutritionists in human behaviour, 2) update regulations for sports nutrition profession practice to acknowledge the skills required to support athletes' emotional wellbeing, 3), educate coaches on the sensitivity of body weight and composition and develop guidelines for monitoring athletes' body weight and composition in sport, 4) persuade influential leaders to develop culture guidelines that shift the performance-narrative of high-performance (i.e., environmental restructuring).