BackgroundSchool physical education (PE) is considered as an effective channel for youth to accumulate moderate-to-vigorous physical activity (MVPA) and reduce sedentary time. The purpose of this study was to determine the contributing role of PE in daily MVPA and sedentary time among youth.MethodsThe study recruited 67 sixth grade children (29 boys; Mean age = 11.75) from two suburban schools at a U.S. Midwest state, 48 of whom contributed ≥10 hours of physical activity (PA) data per day were included for analysis. An objective monitoring tool (i.e., Sensewear armband monitor) was used to capture the participants’ MVPA and sedentary time for 7–14 days. Pearson product–moment correlation analysis (r), multi-level regression analyses, and analysis of variance were conducted for data analysis.ResultsMVPA and sedentary time in PE showed significant positive associations with daily MVPA and sedentary time, respectively (r = 0.35, p < 0.01; r = 0.55, p < 0.01). Regression analyses revealed that one minute increase in MVPA and sedentary behavior in PE was associated with 2.04 minutes and 5.30 minutes increases in daily MVPA and sedentary behavior, respectively, after controlling for sex and BMI. The participants demonstrated a significantly higher level of MVPA (p = .05) but similar sedentary time (p = 0.61) on PE days than on non-PE days. Boys had significantly more daily MVPA (p < .01) and less sedentary time (p < .01) than girls; while higher BMI was associated with more sedentary time (p < .01).ConclusionsPE displayed a positive contribution to increasing daily MVPA and decreasing daily sedentary time among youth. Active participation in PE classes increases the chance to be more active and less sedentary beyond PE among youth.

Transfer request: A self‐assembled supramolecular charge‐transfer complex of 1‐(11‐oxo‐11‐pyren‐1‐ylmethoxy)undecyl)pyridinium bromide (PYR) and ethane‐1,2‐diyl bis(3,5‐dinitrobenzoate) (DNB) is shown to form vesicular aggregates in aqueous solution, in contrast to the tubular aggregates of pure PYR (see picture). A curvature‐dependent mechanism for this change is proposed.

Enhancing the intermolecular interactions between micelles by introducing a strong π–π stacking moiety and flexible spacers of appropriate length results in the formation of disklike micelles that can maintain their monomolecule‐layered structures even when being transferred to hydrophilic substrates (see AFM image, 3 μm×3 μm).

A CO(2)-responsive dispersant, N,N-dimethyl-N'-(pyren-1-ylmethyl) acetimidamidinium (PyAH(+)), which bears both a pyrene moiety and an amidinium cation, has been successfully synthesized. Through strong π-π interaction between the pyrene moiety and single-walled carbon nanotubes (SWNTs), we have demonstrated that PyAH(+) can be modified onto SWNT surfaces to promote the dispersion of SWNTs in water. Furthermore, taking advantage of gas triggered interconversions between the amidinium cation and amidine, reversible control on the solubility of SWNTs has been achieved simply through alternated bubbling of CO(2) and Ar. This work has demonstrated a new method for controlled dispersion and aggregation of SWNTs, and it may contribute to the development of gas responsive carbon materials.

This study demonstrates that students' active exploration and expectancy beliefs for success in physical education have limited influence on leisure-time physical activity participation.

We have succeeded in dispersing single-walled carbon nanotubes (SWNTs) into an aqueous solution of poly(ethylene glycol)-terminated malachite green derivative (PEG-MG) through simple sonication. It was found that UV exposure caused reaggregation of these predispersed SWNTs in the same aqueous medium, as adsorbed PEG-MG photochromic chains could be effectively photocleavaged from the nanotube surface. The observed light-controlled dispersion and reaggragation of SWNTs in the aqueous solution should facilitate the development of SWNT dispersions with a controllable dispersity for potential applications.

The purpose of the study is to examine the associations of youth physical activity and screen time with weight status and cardiorespiratory fitness in children and adolescents, separately, utilizing a nationally representative sample. A total of 1,113 participants (692 children aged 6–11 yrs; 422 adolescents aged 12–15 yrs) from the 2012 NHANES National Youth Fitness Survey. Participants completed physical activity and screen time questionnaires, and their body mass index and cardiorespiratory fitness (adolescents only) were assessed. Adolescents completed additional physical activity questions to estimate daily MET minutes. Children not meeting the screen time guideline had 1.69 times the odds of being overweight/obese compared to those meeting the screen time guideline, after adjusting for physical activity and other control variables. Among adolescent, screen time was significantly associated with being overweight/obese (odds ratio = 1.82, 95% confidence interval: 1.06–3.15), but the association attenuated toward the borderline of being significant after controlling for physical activity. Being physically active was positively associated with cardiorespiratory fitness, independent of screen time among adolescents. In joint association analysis, children who did not meet physical activity nor screen time guidelines had 2.52 times higher odds of being overweight/obese than children who met both guidelines. Adolescents who did not meet the screen time guideline had significantly higher odds ratio of being overweight/obese regardless of meeting the physical activity guideline. Meeting the physical activity guideline was also associated with cardiorespiratory fitness regardless of meeting the screen time guideline in adolescents. Screen time is a stronger factor than physical activity in predicting weight status in both children and adolescents, and only physical activity is strongly associated with cardiorespiratory fitness in adolescents.

BackgroundThere is a need to identify strategies that enhance the implementation of evidence-based school wellness intervention programs in real-world settings. The present study evaluates the feasibility of empowering school wellness leaders to deliver an evidence-based, childhood obesity-prevention program called Switch ™. We specifically evaluated the feasibility of a new implementation framework, based on the robust Healthy Youth Places framework, to increase capacity of school leaders to lead school wellness programming.MethodsThe SWITCH (School Wellness Integration Targeting Child Health) implementation process was evaluated in a convenience sample of eight Iowa elementary schools. Teams of three leaders from each school attended an in-person school wellness conference followed by five online webinar sessions delivered by two SWITCH team members. The capacity-building and quality improvement process was designed to empower schools to lead wellness change using methods and concepts from the original 16-week Switch ™ program. School wellness leaders completed checklists on two occasions to assess overall school-level implementation as well as setting-level changes in physical education, classrooms, and the lunchroom. Student acceptability of SWITCH was evaluated by the degree of behavior tracking using an online SWITCH Tracker system that promoted self-monitoring. School acceptability and practicality were assessed through an exit survey completed by school leaders.ResultsAll school staff reported satisfaction with the SWITCH implementation process. Reports of school- and setting-level implementation were relatively high (2.0 to 2.8 on a 3-point scale) but student engagement, based on use of the online tracking system, varied greatly over time and across schools. Three high implementation schools had average tracking rates exceeding 70% (range: 72–90%) while three low implementation schools had rates lower than 30% (range = 0–23%).ConclusionsThis feasibility study supports the utility of the new implementation framework for promoting school and student engagement with SWITCH. Further testing regarding effectiveness and scale-up of this evidence-based school wellness intervention program is warranted.