The effect of auditory stimulus training on swimming start reaction time

Task-specific auditory training can improve sensorimotor processing times of the auditory reaction time (RT). The majority of competitive swimmers do not conduct habitual start training with the electronic horn used to commence a race. We examined the effect of four week dive training interventions on RT and block time (BT) of 10 male adolescent swimmers (age 14.0 ± 1.4 years): dive training with auditory components (speaker and electronic horn) (n = 5) and dive training without auditory components (n = 5). Auditory stimulus dive training significantly reduced swimming start RT, compared with dive training without auditory components (p < 0.01), with a group mean RT reduction of 13 ± 9 ms. Four of the five swimmers that received auditory stimulus training showed medium to large effect size reductions in RT (d = 0.74; 1.32; 1.40; 1.81). No significant changes to swimmers’ BTs were evident in either dive training intervention. The adolescent swimmers’ results were compared against six male elite swimmers (age 19.8 ± 1.0 years). The elite swimmers had significantly shorter BTs (p < 0.05) but no significant difference in RTs. Auditory stimulus dive training should be explored further as a mechanism for improving swimming start performance in elite swimmers who have pre-established optimal BTs.     

Research Findings from the Tennessee Value-Added Assessment System (TVAAS) Database: Implications for Educational Evaluation and Research

The Tennessee Value-Added Assessment System determines the effectiveness of school systems, schools, and teachers based on student academic growth over time. An integral part of TVAAS is a massive, longitudinally merged database linking students and student outcomes to the schools and systems in which they are enrolled and to the teachers to whom they are assigned as they transition from grade to grade. Research conducted utilizing data from the TVAAS database has shown that race, socioeconomic level, class size, and classroom heterogeneity are poor predictors of student academic growth. Rather, the effectiveness of the teacher is the major determinant of student academic progress. Teacher effects on student achievement have been found to be both additive and cumulative with little evidence that subsequent effective teachers can offset the effects of ineffective ones. For these reasons, a component linking teacher effectiveness to student outcomes is a necessary part of any effective educational evaluation system.     

Warranted uncertainty and students' knowledge and use of drugs

The ability to recognize when it is warranted to be uncertain was developed effectively in 167 elementary school students through daily 15-min lessons over a 5-week period. This initial training did not deal with drug use in any way. A 3-year follow-up evaluation measured retention of these warranted-uncertainty skills, and assessed the effects of these skills on students' use of hard and soft drugs. In comparison with the matched control subjects, there was evidence of some retention after 3 years: the trained subjects were slightly better able to recognize when it is warranted to be uncertain about the effects of drugs. There was also strong evidence that many of the controls had acquired, somehow, the ability to generate warranted uncertainty, and that warranted uncertainty functioned as a stable construct (irrespective of how it was acquired) and was related to drug use. It appeared to produce a skepticism or an analytic attitude that allowed the student to ignore peer and parental dogma about drugs.     

Brand’s Social Media Presence as Networks: The Role of Interactivity and Network Centrality on Engagement

Despite ample research on brand engagement via social media, little research considers the aggregate effect of multiple same-brand accounts on engagement. Multiple same-brand accounts are common because they allow brands to extend their reach, tailor their messaging, and cross-promote their products/services. Therefore, this study tests whether interaction between same-brand social media accounts and centrality within same-brand conversational networks is related to user engagement. An analysis of 3,380 brand accounts found that after controlling for interactions with users, interactions between brand accounts contributed significantly to user engagement and that account centrality measures were associated with measures of engagement.     

Hydrodynamics of undulatory underwater swimming: A review

Undulatory underwater swimming (UUS) occurs in the starts and turns of three of the four competitive swimming strokes and plays a significant role in overall swimming performance. The majority of research examining UUS is comparative in nature, dominated by studies comparing aquatic animals' undulatory locomotion with the UUS performance of humans. More recently, research directly examining human forms of UUS have been undertaken, providing further insight into the factors which influence swimming velocity and efficiency. This paper reviews studies which have examined the hydromechanical, biomechanical, and coordination aspects of UUS performance in both animals and humans. The present work provides a comprehensive evaluation of the key factors which combine to influence UUS performance examining (1) the role of end-effector frequency and body amplitudes in the production of a propulsive waveform, (2) the effects of morphology on the wavelength of the propulsive waveform and its subsequent impact on the mode of UUS adopted, and (3) the interactions of the undulatory movements to simultaneously optimise propulsive impulse whilst minimising the active drag experienced. In conclusion, the review recommends that further research is required to fully appreciate the complexity of UUS and examine how humans can further optimise performance.     

Effect of wetted surface area on friction,pressure, wave and total drag of a kayak

Using theoretical principles, the components of drag (friction D _F, pressure D _PR and wave D _W) of a single-seat kayak were analysed. The purpose was to examine the effect of changes in wetted surface area due to changes in kayaker’s weight and the relative contribution of D _F, D _PR and D _W to the total passive drag as function of velocity. The total passive drag values were based on experimental data collected in a single-seat kayak. Three different kayaker simulated weights were tested – 65, 75 and 85 kg. D _F was the drag component that contributed the greatest percentage (between 60 and 68% at 5.56 m/s the top velocity tested) to the total passive drag for all the velocities tested and simulated weights. D _W was the most affected by the increase in kayaker’s simulated weight, mainly when comparing 65/75 to 85 kg. Results support the importance of a kayak design selection that minimises the kayak’s drag for the individual weight of the kayaker. Also, the results suggest that the path for better hydrodynamic kayak performance should seek changes that can reduce D _F, D _PR and D _W with D _F offering the most potential to reduce passive drag.     

Biomechanics teachers can be animals

The aim of this study was to determine whether a constructivist approach, in particular a visit to a zoo, could be effective in consolidating mechanical concepts and applying those concepts to coaching and teaching. Ten students in their final year of their Bachelor of Physical Education at the University of Edinburgh participated in a visit to Edinburgh Zoo. During the visit students completed a worksheet of questions and engaged interactively in discussing how various animals are adapted mechanically to survive in their environments. Immediately after the visit they completed a questionnaire with four sections. The first section assessed whether they could apply the mechanical concepts discussed during the visit to human sports performance. The second canvassed their opinions on whether the visit was effective in reinforcing mechanical concepts, in developing 'lateral thinking' about mechanical concepts, and in improving their ability to apply mechanical concepts to coaching and teaching. The third canvassed their opinions on whether the visit would be effective for senior high school Physical Education and Sports Science students for developing mechanical concepts and applying them to coaching. The fourth section canvassed their opinions on when the visit should be conducted for Physical Education and Sports Science students in universities and in senior high schools. The results indicated that the visit was effective in reinforcing mechanical concepts and in applying them laterally to improve understanding of human sports performance. Participants believed that the visit would also be effective for senior high school students. All participants believed that the visit would be most beneficial after at least one course in biomechanics that covers the basic biomechanical principles.     

Technique and timing in women's and men's reverse one and one half somersault with two and one half twists (5335D) and men's reverse one and one half somersault with three and one half twists (5337D) 3 m springboard dives

The purpose of this study was to compare timing and technique of males and females performing reverse twisting dives in elite international competition. Video data of the dives performed at the 1999 FINA World Diving Cup were captured and digitised to obtain times and postures of the divers at specific events including takeoff and entry. Estimates of flight height and mass-normalised work done on the springboard were obtained from flight times. The data indicated that many males are able to complete an additional twist rotation because they attain more height, and therefore more time in the air, than females.     

Implementation and Outcomes of Supplemental Educational Services: The Tennessee State-Wide Evaluation Study

Supplemental Educational Services (SES), a component of the No Child Left Behind (NCLB) Act, provides free tutoring to economically disadvantaged children who are attending Title I schools in their 2nd or more years of school improvement. This research evaluated SES in Tennessee to determine the: (a) impacts on student achievement, and (b) perceptions of SES implementation and outcomes by teachers, district coordinators, principals/site coordinators, and parents. Using value-added methodology, statistical analyses of achievement data controlled for both student ability and teacher effects in 2 alternative models. Not surprisingly, parent reactions to SES were highly positive, whereas those by the 3 other stakeholder groups were more mixed. Achievement results from both analytical models yielded mostly small and nonsignificant provider effects. The implications of the findings for evaluating SES are discussed with regard to both research and policy issues. Recommendations are offered for broadening the evaluation of SES through smaller mixed-methods studies to examine implementation and educational outcomes in more highly controlled contexts.