327 research outputs found
Low fundamental movement skill proficiency is associated with high BMI and body fatness in girls but not boys aged 6-11 years old
This study examined differences in children’s Body Mass Index (BMI) and body fatness (BF%) as a function of gender and fundamental movement skill (FMS) proficiency. Following ethics approval and parental consent, 248, 6-11 year old children (112 boys, 136 girls) underwent assessment of seven FMS: sprint run, side gallop, hop, kick, catch, throw, vertical jump. FMS tertiles (‘high’, ‘medium’ or ‘low’ FMS) were created based on the summed components of the FMS. Skinfold measures were used to calculate BF%. Physical activity (PA) was assessed using pedometry and maturation predicted using anthropometry. Data were analysed using a 2 (Gender) X 3 (FMS tertile) ways ANCOVA, controlling for age, maturation and PA. Age (P = .001) and maturation (P = .006) were associated with BMI. Girls classified as high FMS proficiency had significantly lower BMI compared to girls with low and medium FMS proficiency. Age (P = .0001) and maturation (P = .007) were associated with BF%. BF% was also higher for girls with low FMS compared to those with medium and high FMS. BF% and BMI were not different across FMS tertile in boys. Such findings suggest focusing on FMS may be especially important for healthy weight, particularly in girls. This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Sports Sciences on 21 Nov 2016 available online: http://www.tandfonline.com/ 10.1080/02640414.2016.1258483
On the performance of algorithms for the minimization of -penalized functionals
The problem of assessing the performance of algorithms used for the
minimization of an -penalized least-squares functional, for a range of
penalty parameters, is investigated. A criterion that uses the idea of
`approximation isochrones' is introduced. Five different iterative minimization
algorithms are tested and compared, as well as two warm-start strategies. Both
well-conditioned and ill-conditioned problems are used in the comparison, and
the contrast between these two categories is highlighted.Comment: 18 pages, 10 figures; v3: expanded version with an additional
synthetic test problem
The ethics of uncertainty for data subjects
Modern health data practices come with many practical uncertainties. In this paper, I argue that data subjects’ trust in the institutions and organizations that control their data, and their ability to know their own moral obligations in relation to their data, are undermined by significant uncertainties regarding the what, how, and who of mass data collection and analysis. I conclude by considering how proposals for managing situations of high uncertainty might be applied to this problem. These emphasize increasing organizational flexibility, knowledge, and capacity, and reducing hazard
Fundamental movement skills in relation to weekday and weekend physical activity in preschool children.
OBJECTIVES: To examine associations between fundamental movement skills and weekday and weekend physical activity among preschool children living in deprived communities. DESIGN: Cross-sectional observation study. METHODS: Six locomotor skills and 6 object-control skills were video-assessed using The Children's Activity and Movement in Preschool Study Motor Skills Protocol. Physical activity was measured via hip-mounted accelerometry. A total of 99 children (53% boys) aged 3-5 years (M 4.6, SD 0.5) completed all assessments. Multilevel mixed regression models were used to examine associations between fundamental movement skills and physical activity. Models were adjusted for clustering, age, sex, standardised body mass index and accelerometer wear time. RESULTS: Boys were more active than girls and had higher object-control skill competency. Total skill score was positively associated with weekend moderate-to-vigorous physical activity (p=0.034) but not weekday physical activity categories (p>0.05). When subdomains of skills were examined, object-control skills was positively associated with light physical activity on weekdays (p=0.008) and with light (p=0.033), moderate-to-vigorous (p=0.028) and light- and moderate-to-vigorous (p=0.008) physical activity at weekends. Locomotor skill competency was positively associated with moderate-to-vigorous physical activity on weekdays (p=0.016) and light physical activity during the weekend (p=0.035). CONCLUSIONS: The findings suggest that developing competence in both locomotor and object-control skills may be an important element in promoting an active lifestyle in young children during weekdays and at weekends
Computing environments for reproducibility: Capturing the 'Whole Tale'
The act of sharing scientific knowledge is rapidly evolving away from traditional articles and presentations to the delivery of executable objects that integrate the data and computational details (e.g., scripts and workflows) upon which the findings rely. This envisioned coupling of data and process is essential to advancing science but faces technical and institutional barriers. The Whole Tale project aims to address these barriers by connecting computational, data-intensive research efforts with the larger research process—transforming the knowledge discovery and dissemination process into one where data products are united with research articles to create “living publications” or tales. The Whole Tale focuses on the full spectrum of science, empowering users in the long tail of science, and power users with demands for access to big data and compute resources. We report here on the design, architecture, and implementation of the Whole Tale environment
RELATIONSHIP BETWEEN BAT MASS PROPERTIES AND BAT VELOCITY
Seventeen male collegiate baseball players and seventeen female collegiate softball players were tested hitting with aluminum alloy bats with various weights and moments of inertia. The ball and bat were tracked with a motion analysis system. ANOVA revealed significant differences in bat linear velocity among the baseball bats and among the softball bats. Variations in bat angular velocity were non-significant for both the baseball bats and softball bats. There was a linear correlation between linear velocity and moment of inertia for both baseball and softball bats. To limit bat velocity, regulating both bat weight and center of gravity location would be a practical solution
Motor competence and its effect on positive developmental trajectories of health
In 2008, Stodden and colleagues took a unique developmental approach toward addressing the potential
role of motor competence in promoting positive or negative trajectories of physical activity, health-related fitness, and weight status. The conceptual model proposed synergistic relationships among physical activity, motor competence, perceived motor competence, health-related physical fit ness, and obesity with associations hypothesized to strengthen over time. At the time the model was proposed, limited evidence was available to support or refute the model hypotheses. Over the past 6 years, the number of investigations exploring these relationships has increased significantly. Thus, it is an appropriate time to examine
published data that directly or indirectly relate to specific pathways noted in the conceptual model. Evidence indi cates that motor competence is positively associated with perceived competence and multiple aspects of health (i.e., physical activity, cardiorespiratory fitness, muscular strength, muscular endurance, and a healthy weight status). However, questions related to the increased strength of associations across time and antecedent/consequent mech anisms remain. An individual’s physical and psychological development is a complex and multifaceted process that synergistically evolves across time. Understanding the
most salient factors that influence health and well-being and how relationships among these factors change across time is a critical need for future research in this area. This knowledge could aid in addressing the declining levels of physical activity and fitness along with the increasing rates of obesity across childhood and adolescence.4811-99FE-2ECD | Luis Paulo Rodriguesinfo:eu-repo/semantics/publishedVersio
Obesity-induced decreases in muscle performance are not reversible by weight loss
Background/Objectives: Obesity can affect muscle phenotypes, and may thereby constrain movement and energy expenditure. Weight loss is a common and intuitive intervention for obesity, but it is not known whether the effects of obesity on muscle function are reversible by weight loss. Here we tested whether obesity-induced changes in muscle metabolic and contractile phenotypes are reversible by weight loss.Subjects/Methods: We used zebrafish (Danio rerio) in a factorial design to compare energy metabolism, locomotor capacity, muscle isometric force and work-loop power output, and myosin heavy chain composition between lean fish, diet-induced obese fish, and fish that were obese and then returned to lean body mass following diet restriction.Results: Obesity increased resting metabolic rates (p < 0.001) and decreased maximal metabolic rates (p = 0.030), but these changes were reversible by weight-loss, and were not associated with changes in muscle citrate synthase activity. In contrast, obesity-induced decreases in locomotor performance (p = 0.0034), and isolated muscle isometric stress (p = 0.01), work loop power output (p < 0.001), and relaxation rates (p = 0.012) were not reversed by weight loss. Similarly, obesity-induced decreases in concentrations of fast and slow myosin heavy chains, and a shift towards fast myosin heavy chains were not reversed by weight loss.Conclusion: Obesity-induced changes in locomotor performance and muscle contractile function were not reversible by weight loss. These results show that weight loss alone may not be a sufficient intervention
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