Convenience Over Nutrition for Recreation League Youth Sport Team Snack and Mealtime Choices

Fifty-six percent of school-aged children participate in team sports, yet there is limited evidence on how participation in youth sports impacts the dietary behaviors of participants and their families. Our team surveyed parents and caregivers of children participating in recreation league youth sports (n = 178) to assess the foods and beverages offered as team snacks and factors that influence team snack choices. Juice was the most popular beverage, and crackers were the most popular snack reported by parents. Convenience, followed by cost and child preference, were the most frequently reported factors influencing team snack choices. Survey items also included factors that influence mealtime behaviors on game and practice days. Convenience, followed by nutrition and taste, were most frequently reported as factors that influenced mealtime behaviors. Almost half of parents said their family’s eating habits changed as a result of recreational youth sports activities, and more than half said their family often or always eats dinner outside of the home on game and practice days. Professionals who work with this age group and their parents, including extension agents, can tailor education to encourage healthy team snacks and promote strategies to make healthy meals accessible on evenings with youth sports

Evaluation of density separation and other treatment methods for plastic media blasting (PMB) waste

The United States Air Force has developed plastic media blasting (PMB) to replace solvent paint stripping of its aircraft. This paint blasting operation generates a waste stream of mainly pulverized plastic, but the stream also contains enough paint pigments to make the PMB waste RCRA hazardous. A Phase I study identified density separation as the preferred treatment alternative to land disposal of the entire PMB waste stream in a hazardous landfill. This study found density separation to be a less attractive alternative to self-encapsulation, solidification/stabilization (S/S), and low-temperature ashing. Self-encapsulation resulted in a volume decrease but only moderate improvement in Toxicity Characteristic Leaching Procedure (TCLP) performance Solidification/Stabilization (S/S) into cementiaous waste for resulted in excellent TCLP performances, but volume increases. Low-temperature ashing resulted in dramatic volume decreases, but off-gas control is required to contain all the RCRA metals. The resulting ash must be stabilized (e.g., S/S) to meet TCLP limits

Superconductors with Magnetic Impurities: Instantons and Sub-gap States

When subject to a weak magnetic impurity potential, the order parameter and quasi-particle energy gap of a bulk singlet superconductor are suppressed. According to the conventional mean-field theory of Abrikosov and Gor'kov, the integrity of the energy gap is maintained up to a critical concentration of magnetic impurities. In this paper, a field theoretic approach is developed to critically analyze the validity of the mean field theory. Using the supersymmetry technique we find a spatially homogeneous saddle-point that reproduces the Abrikosov-Gor'kov theory, and identify instanton contributions to the density of states that render the quasi-particle energy gap soft at any non-zero magnetic impurity concentration. The sub-gap states are associated with supersymmetry broken field configurations of the action. An analysis of fluctuations around these configurations shows how the underlying supersymmetry of the action is restored by zero modes. An estimate of the density of states is given for all dimensionalities. To illustrate the universality of the present scheme we apply the same method to study `gap fluctuations' in a normal quantum dot coupled to a superconducting terminal. Using the same instanton approach, we recover the universal result recently proposed by Vavilov et al. Finally, we emphasize the universality of the present scheme for the description of gap fluctuations in d-dimensional superconducting/normal structures.Comment: 18 pages, 9 eps figure

The Muonium Atom as a Probe of Physics beyond the Standard Model

The observed interactions between particles are not fully explained in the successful theoretical description of the standard model to date. Due to the close confinement of the bound state muonium ($M = \mu^+ e^-$) can be used as an ideal probe of quantum electrodynamics and weak interaction and also for a search for additional interactions between leptons. Of special interest is the lepton number violating process of sponteanous conversion of muonium to antimuonium.Comment: 15 pages,6 figure

Chiral Symmetry and light resonances in hot and dense matter

We present a study of the $\pi\pi$ scattering amplitude in the $\sigma$ and $\rho$ channels at finite temperature and nuclear density within a chiral unitary framework. Meson resonances are dynamically generated in our approach, which allows us to analyze the behavior of their associated scattering poles when the system is driven towards chiral symmetry restoration. Medium effects are incorporated in three ways: (a) by thermal corrections of the unitarized scattering amplitudes, (b) by finite nuclear density effects associated to a renormalization of the pion decay constant, and complementarily (c) by extending our calculation of the scalar-isoscalar channel to account for finite nuclear density and temperature effects in a microscopic many-body implementation of pion dynamics. Our results are discussed in connection with several phenomenological aspects relevant for nuclear matter and Heavy-Ion Collision experiments, such as $\rho$ mass scaling vs broadening from dilepton spectra and chiral restoration signals in the $\sigma$ channel. We also elaborate on the molecular nature of $\pi\pi$ resonances.Comment: 14 pages, 14 figures. Contribution to Hard Probes 2008, Illa de A Toxa, Spain, June 8th-14th 200

A Caenorhabditis elegans assay of seizure-like activity optimised for identifying antiepileptic drugs and their mechanisms of action

BACKGROUND: Epilepsy affects around 1% of people, but existing antiepileptic drugs (AEDs) only offer symptomatic relief and are ineffective in approximately 30% of patients. Hence, new AEDs are sorely needed. However, a major bottleneck is the low-throughput nature of early-stage AED screens in conventional rodent models. This process could potentially be expedited by using simpler invertebrate systems, such as the nematode Caenorhabditis elegans. NEW METHOD: Head-bobbing convulsions were previously reported to be inducible by pentylenetetrazol (PTZ) in C. elegans with loss-of-function mutations in unc-49, which encodes a GABAA receptor. Given that epilepsy-linked mutations in human GABAA receptors are well documented, this could represent a clinically-relevant system for early-stage AED screens. However, the original agar plate-based assay is unsuited to large-scale screening and has not been validated for identifying AEDs. Therefore, we established an alternative streamlined, higher-throughput approach whereby mutants were treated with PTZ and AEDs via liquid-based incubation. RESULTS: Convulsions induced within minutes of PTZ exposure in unc-49 mutants were strongly inhibited by the established AED ethosuximide. This protective activity was independent of ethosuximide's suggested target, the T-type calcium channel, as a null mutation in the worm cca-1 ortholog did not affect ethosuximide's anticonvulsant action. COMPARISON WITH EXISTING METHOD: Our streamlined assay is AED-validated, feasible for higher throughput compound screens, and can facilitate insights into AED mechanisms of action. CONCLUSIONS: Based on an epilepsy-associated genetic background, this C. elegans unc-49 model of seizure-like activity presents an ethical, higher throughput alternative to conventional rodent seizure models for initial AED screens