Association Between the Frequency of Physical Education Classes and the Prevalence of Overweight/Obesity in Adolescents

Background/Objective: Overweight and obesity has been steadily on the rise in the United States for all groups. The prevalence of obesity for adolescents has tripled since 1980. The purpose of this study is to determine an association between the frequency of physical education classes and the prevalence of overweight/obesity in adolescents in the United States.Methods: This was a cross-sectional study that used the 2001 Youth Risk Behavior Survey (YRBS) of the Center for Disease Control. The outcome variable for the study was Body Mass Index (BMI). A BMI of 25 or greater was considered overweight or obese. The main independent variable was frequency of attending physical education classes. Other independent variables were included such as demographics, nutrition, physical activity, and drug use. Univariate and multivariate statistical analysis methods were used to calculate the odds ratios for frequency of physical education classes and other risk factors for overweight and obesity. Adjusted odds ratios and their 95% confidence intervals were calculated by using a multivariate logistic regression model. SPSS 11.0 and Epinfo 6.04 were the statistical software used for the statistical analysis. Results: The study indicates that about 26% of adolescents in the United States are either overweight or obese. It was found that about 50% of adolescents do not attend PE class at all during the week. No statistically significant relationship was found between enrollment in physical education classes and overweight/obesity in adolescents, adjusting for confounders (OR=0.95 CI=0.81-1.11). There was no statistically significant relationship between the frequency of physical education classes and the overweight/obesity of adolescents, adjusting for confounders (OR=1.01 CI=0.95-1.08).Conclusion: The data shows that there is no direct relationship between the frequency of physical education classes and the prevalence of overweight/obesity, although there is a direct correlation between physical activity and the prevalence of overweight/obesity, which is found in the literature. The content of physical education classes needs to be assessed as well as providing more classes that incorporate physical activity

Na atomic order, Co charge disproportionation and magnetism in Nax_{x}CoO2_{2} for large Na contents

We have synthesized and characterized four different stable phases of Na ordered Na$_{x}$CoO$_{2}$, for $0.65<x<0.8$. Above 100 K they display similar Curie-Weiss susceptibilities as well as ferromagnetic $q=0$ spin fluctuations in the CoO$_{2}$ planes revealed by $^{23}$Na NMR data. In all phases from $^{59}$Co NMR data we display evidences that the Co disproportionate already above 300 K into non magnetic Co$^{3+}$ and magnetic $\approx$Co$^{3.5+}$ sites on which holes delocalize. This allows us to understand that metallic magnetism is favored for these large Na contents. Below 100 K the phases differentiate, and a magnetic order sets in only for $x\gtrsim 0.75$ at $T_{N}=$22 K. We suggest that the charge order also governs the low $T$ energy scales and transverse couplings

59Co NMR study of the Co states in superconducting and anhydrous cobaltates

$^{59}$Co NMR spectra in oriented powders of Na$_{0.35}$CoO$_{2}$ and in its hydrated superconducting phase (HSC) Na$_{0.35}$CoO$_{2}$,1.3H$_{2}$O reveal a single electronic Co state with identical $T$ independent NMR shift tensor. These phases differ markedly from Na$_{0.7}$CoO$_{2}$, in which we resolve 3 types of Co sites. The large T variation of their spin susceptibilities $\chi ^{s}$ and the anisotropy of the orbital susceptibility $\chi ^{orb}$ allow us to conclude that charge disproportionation occurs, in a non magnetic Co$^{3+}$ and two magnetic sites with about 0.3 and 0.7 holes in the $t_{2g}$ multiplet. The data are consistent with those for the single Co site in the anhydrous and HSC phase assuming the expected Co$^{3.65+}$ charge.Comment: 5 pages, 3 figures, accepted for publication in Phys. Rev. Let

QS-21 Adjuvant: Laboratory-Scale Purification Method and Formulation Into Liposomes.

QS-21, a saponin extracted from the tree Quillaja saponaria Molina, is a vaccine adjuvant which has been shown to elicit robust antibody and cell-mediated immune responses in a variety of preclinical and clinical studies [1]. Its purification from the natural source is a lengthy and difficult process. The commercially available saponin mixture Quil-A® is a fraction of the bark extract containing a variety of saponins, including QS-21. In order to facilitate access to QS-21 at laboratory-scale amounts, we propose here a method of purification of QS-21 starting from Quil-A®. In addition, we describe a protocol to appropriately formulate QS-21 into cholesterol-containing, neutral liposomes which are known to decrease QS-21's hemolytic activity while retaining the adjuvant effect. Methods for the physicochemical characterization of purified QS-21 and of the QS-21/liposome formulations are also described

Limited effectiveness of high-dose liposomal amphotericin B (AmBisome) for treatment of visceral leishmaniasis in an Ethiopian population with high HIV prevalence.

Due to unacceptably high mortality with pentavalent antimonials, Médecins Sans Frontières in 2006 began using liposomal amphotericin B (AmBisome) for visceral leishmaniasis (VL) patients in Ethiopia who were severely ill or positive for human immunodeficiency virus (HIV)