Qualitative Criterion for Interception in a Pursuit/Evasion Game

A qualitative account is given of a differential pursuit/evasion game. A criterion for the existence of an intercept solution is obtained using future cones that contain all attainable trajectories of target or interceptor originating from an initial position. A sufficient and necessary conditon that an opportunity to intercept always exist is that, after some initial time, the future cone of the target be contained within the future cone of the interceptor. The sufficient condition may be regarded as a kind of Nash equillibrium.Comment: 8 pages; revsions and corrigend

Effects of exercise on BMI z-score in overweight and obese children and adolescents: a systematic review with meta-analysis

Background: Overweight and obesity are major public health problems in children and adolescents. The purpose of this study was to conduct a systematic review with meta-analysis to determine the effects of exercise (aerobic, strength or both) on body mass index (BMI) z-score in overweight and obese children and adolescents. Methods: Studies were included if they were randomized controlled exercise intervention trials ≥ 4 weeks in overweight and obese children and adolescents 2 to 18 years of age, published in any language between 1990–2012 and in which data were available for BMI z-score. Studies were retrieved by searching eleven electronic databases, cross-referencing and expert review. Two authors (GAK, KSK) selected and abstracted data. Bias was assessed using the Cochrane Risk of Bias Assessment Instrument. Exercise minus control group changes were calculated from each study and weighted by the inverse of the variance. All results were pooled using a random-effects model with non-overlapping 95% confidence intervals (CI) considered statistically significant. Heterogeneity was assessed using Q and I 2 while funnel plots and Egger’s regression test were used to assess for small-study effects. Influence and cumulative meta-analysis were performed as well as moderator and meta-regression analyses. Results: Of the 4,999 citations reviewed, 835 children and adolescents (456 exercise, 379 control) from 10 studies representing 21 groups (11 exercise, 10 control) were included. On average, exercise took place 4 x week for 43 minutes per session over 16 weeks. Overall, a statistically significant reduction equivalent to 3% was found for BMI z-score Χ; −0:06; 95% CI; ‐0:09 to ‐0:03;Q ¼ 24:9; p ¼ 0:01; I 2 ¼ 59:8%. No small-study effects were observed and results remained statistically significant when each study was deleted from the model once. Based on cumulative meta-analysis, results have been statistically significant since 2009. None of the moderator or meta-regression analyses were statistically significant. The number-needed-to treat was 107 with an estimated 116,822 obese US children and adolescents and approximately 1 million overweight and obese children and adolescents worldwide potentially improving their BMI z-score by participating in exercise. Conclusions: Exercise improves BMI z-score in overweight and obese children and adolescents and should be recommended in this population group. However, a need exists for additional studies on this topic

Effects of Exercise on BMI Z-Score in Overweight and Obese Children and Adolescents: A Systematic Review With Meta-Analysis

Background: Overweight and obesity are major public health problems in children and adolescents. The purpose of this study was to conduct a systematic review with meta-analysis to determine the effects of exercise (aerobic, strength or both) on body mass index (BMI) z-score in overweight and obese children and adolescents. Methods: Studies were included if they were randomized controlled exercise intervention trials ≥ 4 weeks in overweight and obese children and adolescents 2 to 18 years of age, published in any language between 1990–2012 and in which data were available for BMI z-score. Studies were retrieved by searching eleven electronic databases, cross-referencing and expert review. Two authors (GAK, KSK) selected and abstracted data. Bias was assessed using the Cochrane Risk of Bias Assessment Instrument. Exercise minus control group changes were calculated from each study and weighted by the inverse of the variance. All results were pooled using a random-effects model with non-overlapping 95% confidence intervals (CI) considered statistically significant. Heterogeneity was assessed using Q and I 2 while funnel plots and Egger’s regression test were used to assess for small-study effects. Influence and cumulative meta-analysis were performed as well as moderator and meta-regression analyses. Results: Of the 4,999 citations reviewed, 835 children and adolescents (456 exercise, 379 control) from 10 studies representing 21 groups (11 exercise, 10 control) were included. On average, exercise took place 4 x week for 43 minutes per session over 16 weeks. Overall, a statistically significant reduction equivalent to 3% was found for BMI z-score Χ; −0:06; 95% CI; ‐0:09 to ‐0:03;Q ¼ 24:9; p ¼ 0:01; I 2 ¼ 59:8%. No small-study effects were observed and results remained statistically significant when each study was deleted from the model once. Based on cumulative meta-analysis, results have been statistically significant since 2009. None of the moderator or meta-regression analyses were statistically significant. The number-needed-to treat was 107 with an estimated 116,822 obese US children and adolescents and approximately 1 million overweight and obese children and adolescents worldwide potentially improving their BMI z-score by participating in exercise. Conclusions: Exercise improves BMI z-score in overweight and obese children and adolescents and should be recommended in this population group. However, a need exists for additional studies on this topic

Exercise and Adiposity in Overweight and Obese Children and Adolescents: A Systematic Review with Network Meta-analysis of Randomised Trials

Objectives Determine both the effects and hierarchy of effectiveness for exercise interventions (aerobic, strength training or both) on selected measures of adiposity (body mass index (BMI) in kg/m2 , fat mass and per cent body fat) in overweight and obese children and adolescents. Design Network meta-analysis of randomised exercise intervention trials. Setting Any setting where a randomised trial could be conducted. Participants Overweight and obese male and/or female children and adolescents 2–18 years of age. Interventions Randomised exercise intervention trials\u3e4 weeks, published between 1 January 1973 and 22 August 2018, and which included direct and/or indirect evidence for aerobic, strength training or combined aerobic and strength training. Primary outcomes Changes in BMI in kg/m2 , fat mass and per cent body fat. Results Fifty-seven studies representing 127 groups (73 exercise, 54 control) and 2792 participants (1667 exercise, 1125 control) met the criteria for inclusion. Length of training (‍ − X ± SD) averaged 14.1±6.2 weeks, frequency, 3.3±1.1 days per week and duration 42.0±21.0min per session. Significant and clinically important reductions in BMI, fat mass and per cent body fat were observed in aerobic versus control comparisons (BMI, mean, 95%CI -1.0, 1.4 to −0.6; fat mass -2.1, –3.3 to −1.0 kg; per cent fat -1.5, –2.2 to −0.9%) and combined aerobic and strength versus control comparisons (BMI -0.7, –1.4 to −0.1; fat mass -2.5, –4.1 to −1.0 kg; per cent fat, -2.2, –3.2 to −1.2%). A significant reduction in per cent fat was also found for strength vs control comparisons (-1.3,–2.5 to −0.1%). Combined aerobic and strength training was ranked first for improving both fat mass (kg) and per cent body fat while aerobic exercise was ranked first for improving BMI. Conclusions Aerobic and combined aerobic and strength training are associated with improvements in adiposity outcomes in overweight and obese children and adolescents. PROSPERO registration number CRD42017073103

MOXE: An X-ray all-sky monitor for Soviet Spectrum-X-Gamma Mission

A Monitoring Monitoring X-Ray Equipment (MOXE) is being developed for the Soviet Spectrum-X-Gamma Mission. MOXE is an X-ray all-sky monitor based on array of pinhole cameras, to be provided via a collaboration between Goddard Space Flight Center and Los Alamos National Laboratory. The objectives are to alert other observers on Spectrum-X-Gamma and other platforms of interesting transient activity, and to synoptically monitor the X-ray sky and study long-term changes in X-ray binaries. MOXE will be sensitive to sources as faint as 2 milliCrab (5 sigma) in 1 day, and cover the 2 to 20 KeV band

The pregnant worker: how much is too much? Assessing safe activity levels.

Physicians should be able to advise pregnant women about safe amounts of physical activity in the workplace. A computerized literature search was used to review reproductive risks of physical activity, proper clinical evaluation and recommendations of the pregnant worker regarding physical activity, and current State of Hawaii disability legislation pertinent to pregnant workers. This article highlights the importance of making accurate clinical assessments regarding the continuation of work for the healthy pregnant worker and also provides physicians with an approach to assessing physical exposure risks of pregnant workers

Absorption Efficiencies of Forsterite. I: DDA Explorations in Grain Shape and Size

We compute the absorption efficiency (Qabs) of forsterite using the discrete dipole approximation (DDA) in order to identify and describe what characteristics of crystal grain shape and size are important to the shape, peak location, and relative strength of spectral features in the 8-40 {\mu}m wavelength range. Using the DDSCAT code, we compute Qabs for non-spherical polyhedral grain shapes with a_eff = 0.1 {\mu}m. The shape characteristics identified are: 1) elongation/reduction along one of three crystallographic axes; 2) asymmetry, such that all three crystallographic axes are of different lengths; and 3) the presence of crystalline faces that are not parallel to a specific crystallographic axis, e.g., non-rectangular prisms and (di)pyramids. Elongation/reduction dominates the locations and shapes of spectral features near 10, 11, 16, 23.5, 27, and 33.5 {\mu}m, while asymmetry and tips are secondary shape effects. Increasing grain sizes (0.1-1.0 {\mu}m) shifts the 10, 11 {\mu}m features systematically towards longer wavelengths and relative to the 11 {\mu}m feature increases the strengths and slightly broadens the longer wavelength features. Seven spectral shape classes are established for crystallographic a-, b-, and c-axes and include columnar and platelet shapes plus non-elongated or equant grain shapes. The spectral shape classes and the effects of grain size have practical application in identifying or excluding columnar, platelet or equant forsterite grain shapes in astrophysical environs. Identification of the shape characteristics of forsterite from 8-40 {\mu}m spectra provides a potential means to probe the temperatures at which forsterite formed.Comment: 55 pages, 15 figure

Ovule development: genetic trends and evolutionary considerations

Much of our current understanding of ovule development in flowering pants is derived from genetic and molecular studies performed on Arabidopsis thaliana. Arabidopsis has bitegmic, anatropous ovules, representing both the most common and the putative ancestral state among angiosperms. These studies show that key genetic determinants that act to control morphogenesis during ovule development also play roles in vegetative organ formation, consistent with Goethe’s “everything is a leaf” concept. Additionally, the existence of a common set of genetic factors that underlie laminar growth in angiosperms fits well with hypotheses of homology between integuments and leaves. Utilizing Arabidopsis as a reference, researchers are now investigating taxa with varied ovule morphologies to uncover common and diverged mechanisms of ovule development