331 research outputs found

    Development of carbon dioxide laser doppler instrumentation detection of clear air turbulence

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    The analytical, experimental, and developmental aspects of an airborne, pulsed, carbon dioxide laser-optical radar system are described. The laser detects clear air turbulence and performs Doppler measurements of this air-motion phenomenon. Conclusions and recommendations arising from the development of the laser system are presented

    Development of CO2 laser Doppler instrumentation for detection of clear air turbulence, volume 2: Appendices

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    Analyses of the mounting and mount support systems of the clear air turbulence transmitters verify that satisfactory shock and vibration isolation are attained. The mount support structure conforms to flight crash safety requirements with high margins of safety. Restraint cables reinforce the mounts in the critical loaded forward direction limiting maximum forward system deflection to 1 1/4 inches

    Assessment of obesity management in medical examination

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    Obesity is a growing international health problem that has already reached epidemic proportions, particularly within the United States where a majority of the population is overweight or obese. Effective methods of treatment are needed, and should be taught to physicians by efficient means. There exists a disconnect between the rising obesity prevalence with its high toll on medical resources, and the lack of obesity education provided to practitioners in the course of their training. One particular shortfall is the lack of representation of obesity on standardized medical examinations. Physician attitudes toward obesity are influenced by their lack of familiarity with the management of the disease. This may include dietary restriction, increasing physical activity, behavior modification, pharmacotherapy, and surgical interventions. Thus, curricular changes in the medical education of obesity could help reduce morbidity and mortality associated with this disease

    Development of CO2 laser Doppler instrumentation for detection of clear air turbulence, volume 1

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    Modification, construction, test and operation of an advanced airborne carbon dioxide laser Doppler system for detecting clear air turbulence are described. The second generation CAT program and those auxiliary activities required to support and verify such a first-of-a-kind system are detailed: aircraft interface; ground and flight verification tests; data analysis; and laboratory examinations

    Focused laser Doppler velocimeter

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    A system for remotely measuring velocities present in discrete volumes of air is described. A CO2 laser beam is focused by a telescope at such a volume, a focal volume, and within the focusable range, near field, of the telescope. The back scatter, or reflected light, principally from the focal volume, passes back through the telescope and is frequency compared with the original frequency of the laser, and the difference frequency or frequencies represent particle velocities in that focal volume

    School Nutrition Policy: An Evaluation of the Rhode Island Healthier Beverages Policy in Schools

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    Background. School policies limiting the availability of sweetened beverages are often considered to be effective interventions for improving children\u27s diet and weight-related health. This study was designed to examine the effectiveness of the Rhode Island Healthier Beverage Policy in reducing consumption of unhealthy beverages and in producing changes in children\u27s weight status. Method. Students in 2 public middle schools in Rhode Island completed self-reported measures of dietary intake and were measured for height and weight prior to and 1 year following the implementation of a state-mandated healthier beverage policy. An inventory of beverages available in vending machines after the beverage policy was implemented provided a measure of adherence with the statewide policy. Results. Both surveyed schools demonstrated compliance with the beverage policy (ie, greater than 70% of available beverages complied). Self-reported consumption of sweetened beverages did not change significantly following policy implementation. Neither average BMI percentile for age and gender nor frequency of children in each weight category changed significantly 1 year after the policy was implemented. Conclusions. Although the healthier beverage policy was effectively implemented, it did not result in changes in self-reported sweetened beverage consumption or weight status 1 year later. Additional school policy and individual-level changes appear to be necessary to effect change in weight and dietary outcomes for children. © 2012 The Author(s)

    Remote detection of trailing vortices, task 3, modification 3

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    The operation of a frequency tracker for use with the laser Doppler velocimeter (LDV) is reported. Topics discussed include: laser beam profile, lens matching, and LDV resolution data. It is concluded that the LDV provides good ground wind signals. The loss in sensitivity of the cavity system at high frequencies is partly compensated by an increase in the scattering cross section of the atmosphere due to dust

    Effect of Experimental Change in Children’s Sleep Duration on Television Viewing and Physical Activity

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    Background Paediatric observational studies demonstrate associations between sleep, television viewing and potential changes in daytime activity levels. Objective(s) To determine whether experimental changes in sleep lead to changes in children's sedentary and physical activities. Methods Using a within-subject counterbalanced design, 37 children 8–11 years old completed a 3-week study. Children slept their typical amount during a baseline week and were then randomized to increase or decrease mean time in bed by 1.5 h/night for 1 week; the alternate schedule was completed the final week. Children wore actigraphs on their non-dominant wrist and completed 3-d physical activity recalls each week. Results Children reported watching more television (p < 0.001) and demonstrated lower daytime actigraph-measured activity counts per epoch (p = 0.03) when sleep was decreased (compared with increased). However, total actigraph-measured activity counts accrued throughout the entire waking period were higher when sleep was decreased (and children were awake for longer) than when it was increased (p < 0.001). Conclusion(s) Short sleep during childhood may lead to increased television viewing and decreased mean activity levels. Although additional time awake may help to counteract negative effects of short sleep, increases in reported sedentary activities could contribute to weight gain over time

    Effect of Prenatal Lifestyle Intervention on Maternal Postpartum Weight Retention and Child Body MassIndex z-score at 36 Months

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    Background/Objectives We previously reported results from a randomized trial showing that a behavioral intervention during pregnancy reduced excess gestational weight gain but did not impact maternal weight at 12 months. We now examine the longer-term effects of this prenatal intervention on maternal postpartum weight retention and toddler body-mass-index z scores (BMIz) over 36 months. Subjects/Methods Pregnant women (N = 264; 13.7 weeks’ gestation; 41.6% Hispanic) with overweight or obesity were randomized into usual care or prenatal intervention. Anthropometric assessments in mothers and toddlers occurred at baseline, 35 weeks’ gestation and after delivery at 6, 12, 18, 24, and 36 months. Results At 36 months, prenatal intervention vs. usual care had no significant effect on the proportion of participants who returned to their early pregnancy weight or below (33.3% vs. 39.5%; p = 0.12) and had no effect on the magnitude of weight retained (2.8 [0.8, 4.8] vs 3.0 kg [1.0, 4.9], respectively; mean difference = 0.14 [−3.0, 2.7]). There was also no statistically significant intervention vs. usual care effect on infant BMIz or skinfold changes over time; toddler BMIz increased by 1.4 [−1.7, 1.0] units in the intervention group and 1.6 [−1.2, 1.8] units in the usual care group from delivery to 36 months (difference = 0.16 [−0.32. 0.63]). The proportion of toddlers at risk for obesity at 36 months was similar in intervention and usual care groups (28/77 [36.4%] vs 30/80 [37.5%]; p = 0.77). Conclusions Compared with usual care, lifestyle intervention during pregnancy resulted in similar maternal and toddler anthropometric outcomes at 36-months postpartum in a diverse US sample of women with overweight and obesity. To sustain improved maternal weight management initiated during pregnancy, continued intervention during the postpartum years may be needed

    Maternal Responsiveness and Toddler Body Mass Index z-Score: Prospective Analysis of Maternal and Child Mealtime Interactions

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    Responsive feeding, where parents are guided by children\u27s hunger and satiation cues and provide appropriate structure and support for eating, is believed to promote healthier weight status. However, few studies have assessed prospective associations between observed parental feeding and toddler growth. We characterized toddler growth from 18 to 36 months and, in a subset of families, examined whether observed maternal responsiveness to toddler satiation cues and encouraging prompts to eat at 18 and 24 months were associated with toddler body mass index z-score (BMIz) from 18 to 36 months. Participants included 163 toddlers and their mothers with overweight/obesity who had participated in a lifestyle intervention during pregnancy. Anthropometrics were measured at 18, 24, and 36 months. In a subsample, mealtime interactions were recorded in families\u27 homes at 18 (n = 77) and 24 (n = 75) months. On average, toddler BMIz remained stable from 18 to 36 months with 31.3% (n = 51) categorized with a healthy weight, 56.4% (n = 92) with at risk for overweight and 12.3% (n = 20) with overweight. Fewer maternal prompts to eat at 18 months was associated with both higher probability of having at risk for overweight/overweight (p \u3c .05), and higher child 36-month BMIz (p = .002). Higher child weight status at 12 months was also associated with both higher probability of having at risk for overweight/overweight (p \u3c .05), and higher child 36-month BMIz (p \u3c .001). Neither 24-month maternal prompts nor 18 or 24 month responsiveness to satiation cues were associated with toddler BMIz. In this diverse sample, weight status was relatively stable from 18 to 36 months. Maternal prompts to eat measured earlier in toddlerhood and prior child weight status were associated with toddler BMIz
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