Information-governing dynamics of attacker-defender interactions in youth rugby union

Previous work on dynamics of interpersonal interactions in 1 vs. 1 sub-phases of basketball has identified changes in interpersonal distance between an attacker and defender as a potential control parameter for influencing organizational states of attacker-defender dyads. Other studies have reported the constraining effect of relative velocity between an attacker and defender in 1 vs. 1 dyads. To evaluate the relationship between these candidate control parameters, we compared the impact of both interpersonal distance and relative velocity on the pattern-forming dynamics of attacker-defender dyads in the sport of rugby union. Results revealed that when interpersonal distance achieved a critical value of less than 4 m, and relative velocity values increased or were maintained above 1 m x s(-1), a successful outcome (i.e. clean attempt) for an attacker was predicted. Alternatively, when values of relative velocity suddenly decreased below this threshold, at the same critical value of interpersonal distance, a successful outcome for the defender was predicted. Data demonstrated how the coupling of these two potential, nested control parameters moved the dyadic system to phase transitions, characterized as a try or a tackle. Observations suggested that relative velocity increased its influence on the organization of attacker-defender dyads in rugby union over time as spatial proximity to the try line increased.     

Are parental concerns about children's inactivity warranted, and are they associated with a supportive home environment?

This paper explores parental concern about children's activity levels and whether parents who are concerned about their child's activity provide a supportive environment. A sample of 615 parents of 5-6-year-old children and 947 parents of 10-12-year-old children completed a questionnaire. Just over 50% of parents reported they were concerned their child was not getting enough activity. Children of concerned parents were less active than those whose parents were not concerned. These findings suggest that parents who are concerned about their child's physical activity levels provided a less supportive environment for physical activity than parents who are not concerned. The challenge for public health will be to harness parental concerns and translate them into action.     

Dog ownership, dog walking, and children's and parents' physical activity

This study aimed to determine cross-sectional associations of dog ownership, dog walking, and physical activity (PA) among children and their parents. Objective measures of PA were obtained for children ages 5-6 and 10-12 years from 19 primary schools across Melbourne, Australia. Parents self-reported their PA, dog ownership, and frequency of dog walking: 53% of families owned a dog, 41% of children who owned a dog did not walk their dog at all, and 32% reported never or rarely walking their dog as a family. Dog ownership was associated with an additional 29 min/day in PA among younger girls, and 70 and 59 min/week more in PA among mothers of younger boys and older girls, respectively. Among mothers of older girls, dog owners were 1.6 times as likely to meet PA guidelines. Mothers with older boys and girls, and fathers with younger boys, who reported walking the dog regularly as a family, spent more time in PA (105, 90, and 158 more min/week, respectively). Promoting dog ownership and dog walking among children and as a family are potential strategies for increasing PA participation in some families.     

Learning dynamics in research alliances: A panel data analysis

The aim of this paper is to empirically test the determinants of Research Joint Ventures’ (RJVs) group dynamics. We develop a model based on learning and transaction cost theories, which represent the benefits and costs of RJV participation, respectively. According to our framework, firms at each period in time weigh the benefits against the costs of being an RJV member. RJV dynamics can then be interpreted as a consequence of this evolving trade-off over time. We look at entry, turbulence and exit in RJVs that have been set up under the US National Cooperative Research Act, which allows for certain antitrust exemptions in order to stimulate firms to co-operate in R&D. Accounting for unobserved project characteristics and controlling for inter-RJV interactions and industry effects, the Tobit panel regressions show the importance of group and time features for an RJVs evolution. We further identify an average RJVs long-term equilibrium size and assess its determining factors. Ours is a first attempt to produce robust stylized facts about co-operational short- and long-term dynamics, a neglected dimension in research co-operations, but an important element in understanding how collaborative learning works.     

Maturity-associated variation in sport-specific skills of youth soccer players aged 13-15 years

The aim of this study was to estimate the contribution of experience, body size and maturity status to variation in sport-specific skills of adolescent soccer players. The participants were 69 players aged 13.2-15.1 years from three clubs that competed in the highest division for their age group. Height and body mass were measured and stage of pubic hair development was assessed at clinical examination. Years of experience in football was obtained at interview. Six football skill tests were administered: ball control with the body, ball control with the head, dribbling with a pass, dribbling speed, shooting accuracy and passing accuracy. Multiple linear regression analysis was used to estimate the relative contributions of age, stage of sexual maturity, height, body mass and years of formal training in soccer to the six skill tests. Age, experience, body size and stage of puberty contributed significantly but in different combinations to the variance in four of the six skill tests: dribbling with a pass (21%; age, stage of maturity), ball control with the head (14%; stage of maturity, height, body height x body mass interaction), ball control with the body (13%; stage of maturity, years of training) and shooting accuracy (8%; stage of maturity, height; borderline significance, P = 0.06). There were no significant predictors for the tests of dribbling speed and passing accuracy. In conclusion, age, experience, body size and stage of puberty contributed relatively little to variation in performance in four of the six soccer-specific skill tests in adolescent footballers aged 13-15 years.     

Introduction to Reference Sources in the Health Sciences: an interview with Jo Anne Boorkman, Jeffrey T. Huber and Fred W. Roper. Interview by Elizabeth Connor

Few works serve as solid a framework for the field of health sciences librarianship or provide as many insights and detailed knowledge as Introduction to Reference Sources in the Health Sciences. Now in its fourth edition, the book's editors and contributors represent an impressive range of experience, expertise, and subject knowledge appreciated by practicing librarians in a variety of settings and by students of health sciences librarianship. Jo Anne Boorkman, Jeffrey T. Huber, and Fred W. Roper answered a series of questions about the latest edition of this seminal work, and offered opinions about reference works, services, and librarians.     

SCISTER act: delivering training in information skills for social-care professionals

PURPOSE: To develop and evaluate a programme of information skills training for social-care practitioners and health-care librarians. SETTING: Two one-day training courses run separately for 13 social-care practitioners and 10 health-care librarians in the Trent geographic region within Northern England. METHODOLOGY: Qualitative and quantitative feedback collected through questionnaires supplemented by participant observation. RESULTS: While generally feedback was favourable, the courses were overly ambitious. More training sessions of shorter duration would offer participants opportunities to practise and use the skills they have acquired. Social-care practitioners responded more positively to skills associated with appraising qualitative research than with randomised controlled trials. Librarians appreciated the opportunity to learn about unfamiliar social-care resources. Both practitioners and health-care librarians reported that they acquired skills to support evidence-based social care as a result of the training intervention. DISCUSSION/CONCLUSION: Involvement of a multi-disciplinary team and support from a social-care information provider maximized the impact of this experimental training intervention.