18 research outputs found
Promoting motor skills in low-income, ethnic children: The Physical Activity in Linguistically Diverse Communities (PALDC) nonrandomized trial
This study reports the long-term effects of a professional learning program for classroom teachers on fundamental motor skill (FMS) proficiency of primary school students from ethnically diverse backgrounds. Design: A cluster non-randomized trial using a nested cross-sectional design. Methods: The study was conducted in 8 primary schools located in disadvantaged and culturally diverse areas in Sydney, Australia. The intervention used an action learning framework, with each school developing and implementing an action plan for enhancing the teaching of FMS in their school. School teams comprised 4-5 teachers and were supported by a member of the research team. The primary outcome was total proficiency score for 7 FMS (run, jump, catch, throw, kick, leap, side gallop). Outcome data were analyzed using mixed effects models. Results: Eight-hundred and sixty-two students (82% response rate) were assessed at baseline in 2006 and 830 (82%) at follow-up in 2010. Compared with students in the control schools, there was a significantly greater increase in total motor skill proficiency among children in the intervention schools at follow-up (adjusted difference = 5.2 components, 95%CI [1.65, 8.75]; p. = 0.01) and in four of the seven motor skills. Conclusions: Training classroom teachers to develop and implement units of work based around individual FMS is a promising strategy for increasing FMS among ethnically diverse children over an extended period of time
A school-based intervention to promote physical activity among adolescent girls: Rationale, design, and baseline data from the Girls in Sport group randomised controlled trial
Background: Physical activity levels decline markedly among girls during adolescence. School-based interventions that are multi-component in nature, simultaneously targeting curricular, school environment and policy, and community links, are a promising approach for promoting physical activity. This report describes the rationale, design and baseline data from the Girls in Sport group randomised trial, which aims to prevent the decline in moderate-to-vigorous intensity physical activity (MVPA) among adolescent girls. Methods/design: A community-based participatory research approach and action learning framework are used with measurements at baseline and 18-month follow-up. Within each intervention school, a committee develops an action plan aimed at meeting the primary objective (preventing the decline in accelerometer-derived MVPA). Academic partners and the State Department of Education and Training act as critical friends. Control schools continue with their usual school programming. 24 schools were matched then randomized into intervention (n = 12) and control (n = 12) groups. A total of 1518 girls (771 intervention and 747 control) completed baseline assessments (86% response rate). Useable accelerometer data (≥ 10 hrs/day on at least 3 days) were obtained from 79% of this sample (n = 1199). Randomisation resulted in no differences between intervention and control groups on any of the outcomes. The mean age (SE) of the sample was 13.6 (± 0.02) years and they spent less than 5% of their waking hours in MVPA (4.85 ± 0.06). Discussion: Girls in Sport will test the effectiveness of schools working towards the same goal, but developing individual, targeted interventions that bring about changes in curriculum, school environment and policy, and community links. By using community-based participatory research and an action learning framework in a secondary school setting, it aims to add to the body of literature on effective school-based interventions through promoting and sustaining increased physical activity participation among adolescent girls
Optical calibration and performance of the adaptive secondary mirror at the Magellan telescope
In this paper we describe the procedure for the optical calibration of large size deformable mirrors, acting as wavefront correctors for adaptive optics systems. Adaptive optics compensate the disturbance due to the atmospheric turbulence to restore the telescope resolution. We will showcase in particular the activities performed for the Adaptive Secondary Mirror (ASM) of the Magellan Adaptive Optics system (MagAO), which is an instrument for the 6.5 m Magellan Clay Telescope, located at Las Campanas Observatory, in Chile. The MagAO ASM calibration is part of the MagAO-2K project, a major MagAO upgrade that started in 2016 with the goal of boosting adaptive optics (AO) correction at visible wavelengths to image exoplanets. For the first time, the optical quality of MagAO mirror is reported. We describe the procedures developed to achieve high SNR interferometric measurements of the ASM modes under the presence of dome convection noise and telescope vibrations. These measurements were required to produce an improved control matrix with up to 500 modes to close the AO loop on sky with enhanced performances. An updated slaving algorithm was developed to improve the control of actuators vignetted by the central obscuration. The calibrations yielded also a new ASM flattening command, updating the one in use since the MagAO commissioning in 2013. With the new flattening command, a 22 nm RMS surface error was achieved. Finally, we present on-sky results showing the MagAO performance achieved with the new calibrations
A naturalistic enquiry into the day-to-day lives of obese children
Childhood obesity has reached epidemic levels in both developed and developing countries, posing one of the greatest challenges to paediatric health in the 21st century. To date, interventions to prevent and treat child obesity have had moderate success, with many researchers advocating the need for individual and community programs combined with a better understanding of the contextual factors affecting children, in particular social and environmental aspects. Little has been documented about the daily experiences of an obese child and the context of their weight-related behaviours. Because of the sensitive nature of child obesity, few studies have employed participant observation methods or naturalistic paradigms to gather contextual information around this prominent health issue. The purpose of this current study was to explain the daily life of an obese child and then determine the context in which weight-related behaviours existed. This study was a naturalistic inquiry employing a multiple case-study design. It was conducted with six obese children and their families in their normal daily environments, including their home, school, and after-school and weekend settings. Participant observations took place from when the child woke in the morning until he/she went to bed at night. Field notes were taken, which were supplemented with digital recordings and casual conversations with key individuals. A number of dietary, physical activity, sedentary and personal factors affecting the weight status of all six children were identified. A cross-case analysis found that there were a number that were common for most children. Common dietary factors included: the consumption of high-sugar or energy-dense snacks; portion sizes; providing food choices; parental dietary patterns; eating in front of the television; and the options available at the school canteen. In relation to physical activity, frequent aspects were: perceived physical activity competence; physical difficulties; participation in a small amount of physical activity after school and on weekends: having people to play with; existence of sibling or parental role models; backyard size; school sport activities; and time available for unstructured physical activity in schools. There were also a number of common factors related to sedentary behaviours, including: enjoyment of these activities; time spent in small screen recreation; regularly reading books; availability of electronic media; friends’ interests in small screen recreation; existence of rules; parental sedentary behaviour patterns; and parental use of small screen recreation as a babysitter. Personal characteristics affecting the weight status of most of the children in the study included: physical appearance self-concept; behavioural self-concept; and peer acceptance self-concept. These factors exerted their influence in a number of the normal day-to-day behaviour settings of these six children. These findings were compared retrospectively with the study’s theoretical framework, Davison and Birch’s Ecological Systems Model (Davison & Birch, 2001), which explores factors affecting a child’s weight status within three broad categories: child characteristics and child risk factors; parenting styles and family characteristics; and community, demographic and societal characteristics. A number of similarities and differences were found between my study’s findings and those presented in Davison and Birch’s model. New risk factors, which were evident in this current study included: personal characteristics which suggested low levels of self-awareness in the social context; sedentary factors such as the enjoyment of the activity and the social inclusion it provided rather than the social exclusion and physical discomfort experienced through physical activity. Both Davison and Birch’s model and this study recognise that the aetiology of child obesity involves complex interactions between individuals and environments. In light of these findings, the development of childhood obesity involves a complex set of factors from a range of contexts that interact to place a child at risk of developing weight problems. It is not simply an imbalance in energy intake and energy expenditure. It is crucial that future interventions cater for risk factors at all three levels, including child, family and the community. Collecting both quantitative and qualitative data at both intraand extra-individual levels may help to reduce some of the methodological limitations associated with child obesity interventions such as using a “one-size fits all” approach, delivering interventions in highly resourced settings and failing to include the entire family and add greater depth to our knowledge of the experiences and characteristics of the obese child
Understanding the day-to-day lives of obese children and their families
This study investigated the daily lives of obese children and their families to better understand factors influencing weight-related behaviors. A multiple case study design was implemented with 6 obese children and their families. Participant observations occurred in different settings from when the children woke until they went to bed, yielding approximately 95 hours of data per family. Lack of parenting skills and role modeling, environments encouraging poor weight-related behaviors, low self-awareness and enjoyment of sedentary activities were common themes. Child obesity involves a complex set of factors interacting to place a child at risk of developing weight problems
Barriers to increasing physical activity and limiting small screen recreation among obese children
Pediatric overweight and obesity, which affects approximately 10% of children worldwide has been described as an epidemic and perhaps as one of the most pressing threats to the health of children and families in developed countries. It is strongly associated with physical and psychosocial health consequences prompting calls for more effective prevention and treatment efforts to curb the current and increasing prevalence
Description and evaluation of a social cognitive model of physical activity behaviour tailored for adolescent girls
The aim of this paper was to describe and test a social cognitive model of physical activity tailored for adolescent girls. Participants were 1518 girls (aged 13.6 ± 0.02 years) from 24 secondary schools in New South Wales, Australia. Useable accelerometer (≥10 hours day−1 on at least 3 days) and questionnaire data were obtained from 68% of this sample (N = 1035). Participants completed questionnaires assessing psychological, behavioural, social and environmental correlates of activity. The theoretical model was tested using structural equation modelling in AMOS. The model explaining accelerometer counts per minute was an adequate-to-good fit to the data (Tucker–Lewis Index = 0.89, the comparative fit index = 0.97 and the root mean square of approximation = 0.098; 90% confidence interval = 0.075–0.122) but explained only 5% of the variance in activity. There were significant model pathways from self-efficacy (r = 0.11, P = 0.01), school environment (r = 0.07, P = 0.02) and physical self-worth (r = 0.07, P = 0.04) to accelerometer counts. Although the proposed model provided an adequate-to-good fit to the data, it explained a small portion of the variance. Shared method variance may explain the larger portions of variance explained in previous studies. Future studies are encouraged to evaluate theories of physical activity behaviour change using objective measures of physical activity
The Simons Observatory: Astro2020 Decadal Project Whitepaper
International audienceThe Simons Observatory (SO) is a ground-based cosmic microwave background (CMB) experiment sited on Cerro Toco in the Atacama Desert in Chile that promises to provide breakthrough discoveries in fundamental physics, cosmology, and astrophysics. Supported by the Simons Foundation, the Heising-Simons Foundation, and with contributions from collaborating institutions, SO will see first light in 2021 and start a five year survey in 2022. SO has 287 collaborators from 12 countries and 53 institutions, including 85 students and 90 postdocs. The SO experiment in its currently funded form ('SO-Nominal') consists of three 0.4 m Small Aperture Telescopes (SATs) and one 6 m Large Aperture Telescope (LAT). Optimized for minimizing systematic errors in polarization measurements at large angular scales, the SATs will perform a deep, degree-scale survey of 10% of the sky to search for the signature of primordial gravitational waves. The LAT will survey 40% of the sky with arc-minute resolution. These observations will measure (or limit) the sum of neutrino masses, search for light relics, measure the early behavior of Dark Energy, and refine our understanding of the intergalactic medium, clusters and the role of feedback in galaxy formation. With up to ten times the sensitivity and five times the angular resolution of the Planck satellite, and roughly an order of magnitude increase in mapping speed over currently operating ("Stage 3") experiments, SO will measure the CMB temperature and polarization fluctuations to exquisite precision in six frequency bands from 27 to 280 GHz. SO will rapidly advance CMB science while informing the design of future observatories such as CMB-S4
Presentazione del documento
The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial configuration of SO will have three small-aperture 0.5-m telescopes and one large-aperture 6-m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping ≈ 10% of the sky to a white noise level of 2 μK-arcmin in combined 93 and 145 GHz bands, to measure the primordial tensor-to-scalar ratio, r, at a target level of σ(r)=0.003. The large aperture telescope will map ≈ 40% of the sky at arcminute angular resolution to an expected white noise level of 6 μK-arcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources
The Simons Observatory: Astro2020 Decadal Project Whitepaper
International audienceThe Simons Observatory (SO) is a ground-based cosmic microwave background (CMB) experiment sited on Cerro Toco in the Atacama Desert in Chile that promises to provide breakthrough discoveries in fundamental physics, cosmology, and astrophysics. Supported by the Simons Foundation, the Heising-Simons Foundation, and with contributions from collaborating institutions, SO will see first light in 2021 and start a five year survey in 2022. SO has 287 collaborators from 12 countries and 53 institutions, including 85 students and 90 postdocs. The SO experiment in its currently funded form ('SO-Nominal') consists of three 0.4 m Small Aperture Telescopes (SATs) and one 6 m Large Aperture Telescope (LAT). Optimized for minimizing systematic errors in polarization measurements at large angular scales, the SATs will perform a deep, degree-scale survey of 10% of the sky to search for the signature of primordial gravitational waves. The LAT will survey 40% of the sky with arc-minute resolution. These observations will measure (or limit) the sum of neutrino masses, search for light relics, measure the early behavior of Dark Energy, and refine our understanding of the intergalactic medium, clusters and the role of feedback in galaxy formation. With up to ten times the sensitivity and five times the angular resolution of the Planck satellite, and roughly an order of magnitude increase in mapping speed over currently operating ("Stage 3") experiments, SO will measure the CMB temperature and polarization fluctuations to exquisite precision in six frequency bands from 27 to 280 GHz. SO will rapidly advance CMB science while informing the design of future observatories such as CMB-S4