The effect of feedback and information on children's pedometer step counts at school

This study examined whether feedback or feedback plus physical activity information could increase the number of pedometer steps taken during 1 school week. One hundred seventy-seven students (mean age 9.124 ± 1.11 years) in three elementary schools participated. Schools were randomly assigned to control (CON), feedback (FB), or feedback plus information (FB+I) groups. Children wore pedometers during school time for 5 consecutive weekdays. The total steps of the groups were recorded at the end of each school day, with students in the FB and FB+I groups free to view their step counts. In addition, the FB+I group received information and ideas about how they could increase their daily steps. The CON group received no step-count feedback or information. Students in the FB+I group achieved significantly more steps per minute (17.17 ± 4.87) than those in the FB (13.77 ± 4.06, p = 0.003) and CON (12.41 ± 3.12, p = 0.0001) groups. Information, as well as step-count feedback, increased elementary students’ school-based physical activity (number of steps) in the short term. A longer intervention period is necessary to assess the sustained impact of this type of approach

Learning from the experts: exploring playground experience and activities using a write and draw technique.

BACKGROUND: Qualitative research into the effect of school recess on children's physical activity is currently limited. This study used a write and draw technique to explore children's perceptions of physical activity opportunities during recess. METHODS: 299 children age 7-11 years from 3 primary schools were enlisted. Children were grouped into Years 3 & 4 and Years 5 & 6 and completed a write and draw task focusing on likes and dislikes. Pen profiles were used to analyze the data. RESULTS: Results indicated 'likes' focused on play, positive social interaction, and games across both age groups but showed an increasing dominance of games with an appreciation for being outdoors with age. 'Dislikes' focused on dysfunctional interactions linked with bullying, membership, equipment, and conflict for playground space. Football was a dominant feature across both age groups and 'likes/dislikes' that caused conflict and dominated the physically active games undertaken. CONCLUSION: Recess was important for the development of conflict management and social skills and contributed to physical activity engagement. The findings contradict suggestions that time spent in recess should be reduced because of behavioral issues

Her Time, His Time, or the Maid's Time: An Analysis of the Demand for Domestic Work

This paper analyzes households' demand for time inputs to domestic services, modeling simultaneously the decision to purchase services in the market and the time spent on weekend and weekday days by each partner on routine household chores. By focusing on cleaning, laundry, and ironing, we reduce the likelihood that preferences matter and increase the overlap with market services. Particular emphasis is placed on estimating the effects of prices, as captured by own and partner wages and the market price for domestic services. We exploit time-diary data for Great Britain and France, relying on cross-country comparisons to generalize our findings. The results indicate that prices strongly influence market purchases, and that maid service is a closer substitute for household time on weekends than weekdays, but is also correlated with 'her' weekday time. More generally, we find that women's wages have a stronger association with the inputs to domestic work than any other price measure.time use, domestic work, gender

Bessel beam propagation: Energy localization and velocity

The propagation of a Bessel beam (or Bessel-X wave) is analyzed on the basis of a vectorial treatment. The electric and magnetic fields are obtained by considering a realistic situation able to generate that kind of scalar field. Specifically, we analyze the field due to a ring-shaped aperture over a metallic screen on which a linearly polarized plane wave impinges. On this basis, and in the far field approximation, we can obtain information about the propagation of energy flux and the velocity of the energy.Comment: 6 pages, 4 figure

Levels and patterns of physical activity in children and adolescents with Type 1 diabetes and associated metabolic and physiologic health outcomes

Background: The present study objectively assessed physical activity (PA) levels and patterns in children and adolescents with type 1 diabetes and compared the metabolic and physiologic health profiles of those achieving and those not achieving the current recommendation of 60 minutes a day (minutes.D-1) of at least moderate intensity PA. Method: 37 children and adolescents (20 boys, 17 girls) aged 12.7 ± 2.1 years (mean ± SD), disease duration 5.9 ± 3.0 years participated. PA was assessed using heart rate monitoring. Peak VO2 , BMI, sum of 5 skinfolds, HbA1c and daily insulin dosage were also determined. Results: Mean accumulated time in moderate-to-vigorous intensity PA was 53.6 ± 31.4 minutes.D-1. Levels of vigorous-intensity PA were low, mean 8.3 ± 10.2 minutes.D-1. When controlling for age, no differences in metabolic or physiologic health outcomes were evident between those individuals achieving, and those not achieving, 60minutes.D-1 of moderate-to-vigorous intensity PA. PA predominantly occurred in short bouts lasting 5 minutes or less. Conclusion: The efficacy of accumulating 60 minutes.D-1 of moderate-to-vigorous intensity PA, in the form of short duration, intermittent bouts of largely unplanned PA, to promote health gains in children and adolescents with type 1 diabetes is questionable

Contents

Contains the table of contents.Office of Scientific Research and Development (OSRD) OEMsr-26

Administrative and Service Personnel

Contains a list of laboratory personnel.Office of Scientific Research and Development (OSRD) OEMsr-26

Management regime and habitat response influence abundance of regal fritillary (Speyeria idalia) in tallgrass prairie

The \u3e2,570,000-ha Flint Hills ecoregion of Kansas, USA, harbors the largest remaining contiguous tract of tallgrass prairie in North America, a unique system, as the remainder of North America’s tallgrass prairie has succumbed to development and conversion. Consequently, the loss and degradation of tallgrass prairie has reduced populations of many North American prairie-obligate species including the regal fritillary (Speyeria idalia) butterfly. Population abundance and occupied range of regal fritillary have declined \u3e99%, restricting many populations to isolated, remnant patches of tallgrass prairie. Such extensive decline has resulted in consideration of the regal fritillary for protection under the Endangered Species Act. Although it is widely accepted that management practices such as fire, grazing, and haying are necessary to maintain prairie ecosystems, reported responses by regal fritillary to these management regimes have been ambiguous.We tested effects of prescribed fire across short, moderate, and long fire-return intervals as well as grazing and haying management treatments on regal fritillary density. We also tested the relative influence of habitat characteristics created by these management regimes by measuring density of an obligate host plant (Viola spp.) and canopy cover of woody vegetation, grasses, forbs/ferns, bare ground, and litter. We found density was at least 1.6 times greater in sites burned with a moderate fire-return interval vs. sites burned with short and long fire-return intervals. Overall management regardless of fire-return interval did not have an effect on density. Percent cover of grass had the strongest positive association, while percent cover of woody vegetation had the greatest negative effect on density. Our results indicate that patch-burning is a viable and perhaps even ideal management strategy for regal fritillary in tallgrass prairie landscapes. Additionally, these results elucidate the importance of fire, particularly when applied at moderate-return intervals to regal fritillary, and corroborate a growing suite of studies that suggest fire is perhaps not as detrimental to populations of regal fritillary as previously believed

Publications and Reports

Contains a list of meeting abstracts, letters to the editor, and technical reports published by the Research Laboratory of Electronics.Office of Scientific Research and Development (OSRD) OEMsr-26