456 research outputs found

    Gamma-hadron families and scaling violation

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    For three different interaction models we have simulated gamma-hadron families, including the detector (Pamir emulsion chamber) response. Rates of gamma families, hadrons, and hadron-gamma ratios were compared with experiments

    Some remarks about simulation of cosmic ray phenomena with use of nuclear interaction models based on the current SPS proton-antiproton data

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    The x-y controversy is studied by introducing models with as many features (except for x and y distributions) in common, as possible, to avoid an extrapolation problem, only primary energies of 500 TeV are considered. To prove the point, Monte Carlo simulations are performed of EAS generated by 500 TeV vertical primary protons. Four different nuclear interaction models were used. Two of them are described elsewhere. Two are: (1) Model M-Y00 - with inclusive x and y distributions behaving in a scaling way; and (2) Model M-F00 - at and below ISR energies (1 TeV in Lab) exactly equivalent to the above, then gradually changing to provide the distributions in rapidity at 155 TeV as given by SPS proton-antiproton. This was achieved by gradual decrease in the scale unit in x distributions of produced secondaries, as interaction energy increases. Other modifications to the M-Y00 model were made

    Electrons, muons and hadrons in extensive air showers and how do they depend on nuclear interaction model, part 2

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    Some of the results of Monte Carlo simulations of extensive air showers for nuclear interactions models are presented. The most significant part of scaling violation effect is generated by the inclusion of rising cross-section. Among the models considered the lowest value for Eo/N(max) is obtained when rapidly rising cross-section and charge exchange are both included (model R-F01). The value is still 1.38 GeV/electron. Except at the highest energies, the sensitivity to atomic mass of the primary is greater than to specific assumptions about multiple production

    Weight gain and dietary intake during pregnancy in industrialized countries - a systematic review of observational studies

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    Background: Gestational weight gain (GWG) above the recently recommended ranges is likely to be related to adverse pregnancy outcomes and therefore a challenge in industrialized countries. Aims: We conducted a systematic review on observational studies in order to gain more evidence on whether diets with lower caloric/protein content or other diets might be associated with lower GWG. Methods: We searched in MEDLINE and EMBASE for observational studies written in English or German reporting associations between diet and GWG in singleton pregnancies of healthy women in industrialized countries. Results: We identified 12 studies which met the inclusion criteria. Five studies suggested significant positive associations between energy intake and GWG, whereas three found no significant association. Further significant positive associations of GWG were reported with respect to protein intake, animal lipids, energy density and a number of different food servings per day, whereas intake of carbohydrates and vegetarian diet were associated with less GWG. Conclusions: We suggest that GWG might be reduced by lower energy intake in pregnancy

    Prospective association between objective measures of childhood motor coordination and sedentary behaviour in adolescence and adulthood

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    BACKGROUND: Higher levels of gross motor coordination are positively associated with physical activity in childhood, but little is known about how they relate to sedentary behaviour. The aim of this study was to investigate the longitudinal association between gross motor coordination at childhood and sedentary behaviour in adolescence and adulthood. METHODS: Data were from the 1970 British Cohort Study (the age 10, 16, and 42-year surveys). At age 10 the participant's mother provided information on how often participants watched TV and played sports and a health visitor administered several tests to assess gross motor coordination. At aged 16 and 42-years participants reported their daily screen and TV time, respectively, and physical activity status. We examined associations between gross motor coordination at age 10 with sedentary behaviour and physical activity at age 16 and 42, using logistic regression. RESULTS: In multivariable models, higher levels of gross motor coordination were associated with lower odds of high screen time (n = 3073; OR 0.79, 95% CI 0.64, 0.98) at 16-years although no associations with physical activity were observed (OR 1.16, 95% CI 0.93, 1.44). Similar associations were observed with TV time in adulthood when participants were aged 42, and in addition high gross motor coordination was also associated with physical activity participation (n = 4879; OR 1.18, 95 % CI 1.02, 1.36). CONCLUSIONS: Intervention efforts to increase physical activity participation and reduce sedentary behaviour over the life course may be best targeted towards children with low gross motor coordination

    Direction of the Musical: Hairspray

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    This project entailed the selection, background research and documentation, casting, direction, and post-production analysis of North Surrey Secondary School\u27s production of Hairspray. Documentation includes research and analysis of the play, and an evaluation of the play as a production vehicle for the Drama and Theatrical Arts Department at North Surrey Secondary School

    A reverse pathway? Actual and perceived skill proficiency and physical activity

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    Purpose: Motor skills are considered a prerequisite to physical activity, yet the relationship may be reciprocal and perceived sports competence might mediate associations.Methods: In 2006/2007, 215 adolescents completed motor skill proficiency (Get Skilled Get Active), perceived sport competence (Physical Self-Perception Profile) and physical activity assessments (Adolescent Physical Activity Recall Questionnaire) as part of the Physical Activity and Skills Study. Using AMOS (Version 7.0), reciprocal relationships were examined between motor skill (object control and locomotor) and moderate to vigorous physical activity (MVPA). Both models were then run in different versions to understand the role of perceived sports competence as a potential mediator. Results: Mean age was 16.4 yr (SD = 0.6), 51.6% (111/215) were females. A reciprocal relationship between object control and MVPA and a one-way relationship from MVPA to locomotor skill was found. When perceived sports competence was examined as a mediator, the best-fitting model versions explained 16% (R&sup2; = 0.16)MVPA variation, and 30% object control (R&sup2; = 0.30), and 12% locomotor skill variation (R&sup2; = 0.12) (reverse relationship). Perceived sports competence partially mediates the relationship between object control proficiency and physical activity for both directions and fully mediates the relationship between physical activity and locomotor skill; but only when locomotor skill is the outcome.Conclusions: If the relationship between object control skill and physical activity is viewed as a &lsquo;&lsquo;positive feedback loop,&rsquo;&rsquo; skill development and increasing physical activity should simultaneously be targeted in physical activity interventions. Increasing perceived sport competence should also be an intervention focus.<br /

    Do Irish adolescents have adequate functional movement skill and confidence?

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    Recent research has shown that post-primary Irish youth are insufficiently active and fail to reach a level of proficiency across basic fundamental movement skills. The purpose of the current research was to gather cross-sectional data on adolescent youth, differentiated by gender, specifically to inform the development of a targeted movement-oriented intervention. Data were collected on adolescents (N=219; mean age: 14.45 ± 0.96 years), within two, mixed gender schools. Data collection included actual and perceived movement measurements; comprising of fundamental movement skills, the functional movement screen, perceived movement confidence and perceived functional confidence. Overall, levels of actual mastery within fundamental and functional movement were low, with significant gender differences observed. Adolescent males scored higher in the overall fundamental movement skill domain (male mean score = 70.87 ± 7.05; female mean score = 65.53 ± 7.13), yet lower within the functional movement screen (male mean score = 13.58 ± 2.59), in comparison to their female counterparts (female mean score = 14.70 ± 2.16). There were high levels of perceived confidence reported within fundamental and functional movement scales. Future intervention strategies should combat the low levels of actual movement skill proficiency, whilst identifying the reasons for higher perceived movement confidence within adolescents

    Associations between sedentary behavior and motor coordination in children

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    DOI 10.1002/ajhb.22310Objectives: This study was conducted to evaluate the relationship between objectively measured sedentary behavior (SB) and motor coordination (MC) in Portuguese children, accounting for physical activity (PA), accelerometer wear time, waist-to-height ratio, and mother’s education level. Methods: A cross-sectional school-based study was conducted on 213 children (110 girls and 103 boys) aged 9–10 in the north of Portugal during the spring of 2010. Accelerometers were used to obtain detailed objective information about daily PA and SB over five consecutive days. MC was measured with a body coordination test (Ko¨rperkoordination Test fu¨ r Kinder). Waist and height were measured by standardized protocols and the waist-to-height ratio (WHtR) was calculated. A questionnaire was used to assess mothers’ educational levels. Receiver-operating characteristic (ROC) and logistic regressions were used. Results: ROC analysis showed that sedentary time significantly discriminated between children with low MC and high MC, with a best trade off between sensitivity and specificity being achieved at 77.29% and 76.48% for girls and boys, respectively (P < 0.05 for both). In both genders, the low sedentary group had significantly higher odds of having good MC than the higher sedentary group, independent of PA, accelerometer wear time, WHtR, and mother’s education level (P < 0.05 for both). Conclusions: Our findings suggested that PA levels per se may not overcome the deleterious influence of high levels of SB on MC. Our data stress the importance of discouraging SB among children to improve MC. Am. J. Hum. Biol. 24:746–752, 2012.CIEC – Research Centre on Child studies, UM (FCT R&D 317).The Portuguese FCT-MCTES; Contract grant number: BD/43808/2008
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