Variable and changing trajectories in youth athlete development: further verification in advocating a long-term inclusive tracking approach.

Athlete development through adolescence can vary greatly because of maturational processes. For example, variation can be observed in anthropometric and fitness measures with later maturing individuals "catching up" their earlier maturing peers at later time points. This study examined a methodological issue concerning how best to assess anthropometric and fitness change (i.e., "across age categories" or "per year") relative to an age and skill-matched population (N = 1,172). Furthermore, it examined changes in anthropometric and fitness characteristics in 3 cases of youth rugby league players (aged 13-15) across a 2-year period. Findings identified the "per year" method as generating less deviated z-scores across anthropometric and fitness measures (e.g., mean change p < 0.001), suggesting less substantial change in case players relative to the population. When applied to additional players, z-score and radar graphs showed developmental variability and longitudinal change. The possibility of a "later maturing player" increasing anthropometric (e.g., height: player 4 = 3.3 cm; player 5 = 13.2 cm; and player 6 = 15.7 cm) and fitness (e.g., 30-m sprint: player 4 = -0.18 s, player 5 = -0.46 s, and player 6 = -0.59 s) characteristics compared with early maturing players was confirmed. Findings affirm the potential for variable and changing trajectories in adolescent athletes. Practical implications advocate a long-term inclusive tracking approach of athletes, the avoidance of (de)selection, and the reduction of a performance emphasis in adolescent stages of sport systems

Privacy-preserving security solution for cloud services

AbstractWe propose a novel privacy-preserving security solution for cloud services. Our solution is based on an efficient non-bilinear group signature scheme providing the anonymous access to cloud services and shared storage servers. The novel solution offers anonymous authenticationfor registered users. Thus, users' personal attributes (age, valid registration, successful payment) can be proven without revealing users' identity, and users can use cloud services without any threat of profiling their behavior. However, if a user breaks provider's rules, his access right is revoked. Our solution provides anonymous access, unlinkability and the confidentiality of transmitted data. We implement our solution as a proof of concept applicationand present the experimental results. Further, we analyzecurrent privacy preserving solutions for cloud services and group signature schemes as basic parts of privacy enhancing solutions in cloud services. We compare the performance of our solution with the related solutionsand schemes

Motor coordination, physical activity and fitness as predictors of longitudinal change in adiposity during childhood

The purpose of this study was to examine the influence of motor coordination (MC), physical fitness (PF) and physical activity (PA) on the development of subcutaneous adiposity in a sample of children followed longitudinally from 6 to 10 years of age. Participants were 142 girls and 143 boys. Height, weight, and the triceps and subscapular skinfolds were measured annually between the ages of 6 and 10 years. PA was estimated with the Godin–Shephard questionnaire. MC was evaluated with the Körperkoordination Test für Kinder (KTK) test battery, and PF was assessed with four Fitnessgram tests: curl-ups (CU), push-ups (PU), trunk-lifts (TL) and one mile run/walk (MRW). Hierarchical linear modelling with MC, PF items and PA as predictors of the sum of two skinfolds (SKF) was used. The results showed that boys and girls differed significantly in SKF at baseline (girls: 19.7 mm; boys: 16.6 mm). Three PF items (CU, PU and MRW) and MC had a positive influence on SKF. For each unit improvement in CU, PU, MRW and MC, SKF was reduced by 0.06, 0.04, 0.06 and 0.12 mm, respectively. In conclusion, motor coordination, muscular strength and endurance, and aerobic endurance attenuated the accumulation of subcutaneous adipose tissue during childhood

non-linear relationships in children 6-10 years

Background: Given the concern for health?related consequences of an elevated body mass index (BMI; obesity), the potential consequences of a low BMI in children are often overlooked. The purpose was to evaluate the relationship between the BMI across its entire spectrum and motor coordination (MC) in children 6?10 years. Methods: Height, weight, and MC (K?rperkoordinationstest f?r Kinder, KTK test battery) were measured in 1,912 boys and 1,826 girls of 6?10 years of age. BMI (kg/m2) was calculated. KTK scores for each of the four tests were also converted to a motor quotient (MQ). One?way ANOVA was used to test differences in the BMI, individual test items, and MQ among boys and girls within age groups. Sex?specific quadratic regressions of individual KTK items and the MQ on the BMI were calculated. Girls and boys were also classified into four weight status groups using International Obesity Task Force criteria: thin, normal, overweight, and obese. Differences in specific test items and MQ between weight status groups were evaluated by age group in each sex. Results: Thirty?one percent of the sample was overweight or obese, whereas 5% was thin. On average, normal weight children had the highest MQ in both sexes across the age range with few exceptions. Overweight/obese children had a lower MQ than normal weight and thin children. The quadratic regression lines generally presented an inverted parabolic relationship between the BMI and MC and suggested a decrease in MC with an increase in the BMI. Conclusion: In general, BMI shows a curvilinear, inverted parabolic relationship with MC in children 6?10 years.4811-99FE-2ECD | Luis Paulo Rodriguesinfo:eu-repo/semantics/publishedVersio

Maturity associated variance in physical activity and health-related quality of life in adolescent females. A mediated effects model

BACKGROUND. This study tested a mediated effects model of psychological and behavioral adaptation to puberty within the context of physical activity (PA). METHODS. Biological maturity status, physical self-concept, PA, and health-related quality of life (HRQoL) were assessed in 222 female British year 7 to 9 pupils (mean age = 12.7 years, SD = .8). RESULTS. Structural equation modeling using maximum likelihood estimation and bootstrapping procedures supported the hypothesized model. Maturation status was inversely related to perceptions of sport competence, body attractiveness, and physical condition; and indirectly and inversely related to physical self-worth, PA, and HRQoL. Examination of the bootstrap-generated bias-corrected confidence intervals representing the direct and indirect paths between suggested that physical self-concept partially mediated the relations between maturity status and PA, and maturity status and HRQoL. CONCLUSIONS. Evidence supports the contention that perceptions of the physical self partially mediate relations maturity, PA, and HRQoL in adolescent females

Analysis of the light dependent resistor configuration for line tracking robot application

Modern days, a robot can be designed based on human needs. In particular, the line tracking robot is a classic introductory robot design and needs minimal amount of material and cost. The aim of this project is to construct a robot that has capability to follow the white line placed on a horizontal smooth surface lighted by LED and the low cost light dependant resistor as the sensor. Rigorous analysis has been applied to determine the optimal configuration for the sensor on the mobile robot. Our findings show that angle of LDR of 30°, the distance between LDR and LED of 2.5cm and height of 2cm is the best configuration. The line tracking robot will detect the light intensity that is rebounded from the white color path

Weight status, BMI and physical fitness in polish youth: relationships between 1986 and 2016

One of the components affecting the level of health is physical fitness and diets, which is also considered the foundation of a healthy lifestyle. Methods: Samples by survey ranged from 871 to 1,417 (boys) and from 843 to 1,326 (girls). Speed (5 m run), agility (figure-8-run), explosive power (vertical jump), flexibility (stand and reach) and cardiovascular fitness (step test) were measured. The Body Mass Index (BMI) of each student was classified as Thin, Normal weight or Overweight/Obese (Owt/Ob) relative to International Obesity Task Force (IOTF) criteria. Fitness items were compared among weight status groups and across surveys with sex-specific analyses of covariance. Regressions of each fitness item on the BMI in the four surveys were done using linear and nonlinear quadratic models. Results: Performances on all fitness tests except flexibility were poorer among Owt/Ob compared to Normal and Thin youth, but performances on fitness tests within weight status groups did not differ consistently across surveys. Conclusions: Relationships between the BMI and fitness tests varied across surveys, but suggested reasonably consistent curvilinear relationships between fitness tests and the BMI among boys more so than girls.info:eu-repo/semantics/publishedVersio

Concurrent and prospective associations among biological maturation, and physical activity at 11 and 13 years of age

This study examined concurrent and prospective associations between objective measures of biological maturation, body composition and physical activity (PA) in adolescent males (n=671) and females (n=680). Participants born to women recruited to the Avon Longitudinal Study of Parents and Children birth cohort study were assessed at 11 and 13 years. Percentage of predicted adult stature was used as an estimate of biological maturation. PA and time sedentary was assessed over 7 consecutive days using Actigraph accelerometers. Body composition was assessed using whole-body DXA scans. At 11 and 13 years, maturity in males was inversely associated with accelerometer counts-per-minute (CPM) and time engaged in light PA, and positively associated with time sedentary. In females, maturity was inversely associated with accelerometer (CPM) at 11 but not 13 years. Adjusting for accelerometer wear times and corresponding activity levels at 11 years, maturity and percentage fat mass at 11 years did not predict any indices of PA or sedentary behavior in males or females at 13 years. Whereas advanced maturation in males is associated with less PA and more sedentary behavior at 11 and 13 years, maturity at 11 does not predict PA or sedentary behavior at 13 years in either sex