An Entropy Stable <Emphasis Type="Italic">h</Emphasis> / <Emphasis Type="Italic">p</Emphasis> Non-Conforming Discontinuous Galerkin Method with the Summation-by-Parts Property

This work presents an entropy stable discontinuous Galerkin (DG) spectral element approximation for systems of non-linear conservation laws with general geometric (h) and polynomial order (p) non-conforming rectangular meshes. The crux of the proofs presented is that the nodal DG method is constructed with the collocated Legendre–Gauss–Lobatto nodes. This choice ensures that the derivative/mass matrix pair is a summation-by-parts (SBP) operator such that entropy stability proofs from the continuous analysis are discretely mimicked. Special attention is given to the coupling between non-conforming elements as we demonstrate that the standard mortar approach for DG methods does not guarantee entropy stability for non-linear problems, which can lead to instabilities. As such, we describe a precise procedure and modify the mortar method to guarantee entropy stability for general non-linear hyperbolic systems on h / p non-conforming meshes. We verify the high-order accuracy and the entropy conservation/stability of fully non-conforming approximation with numerical examples.     

Assessment of 3-D joint contact load predictions during postural/stretching exercises in aged females

Our goal was to estimate knee and hip joint contact forces during a variety of unconstrained "stretching" exercises that are often recommended for people with arthritis. The population of interest was aged females with and without significant osteoarthritis (OA). Three-dimensional (3-D) kinematic, force platform, and selected electromyographic (EMG) data were measured. A relatively standard and reasonably efficient technique was used for all subjects and tasks: inverse dynamics to estimate joint reaction forces and net moments, followed by heuristic reductionist techniques for predicting muscle load-sharing. Muscle force predictions were compatible with measured EMG activity for some tasks but less so for others, especially those with significant axial and medio-lateral movement components or high co-contraction. Such results suggest several improvements, which come at computational cost: 3-D joint models which better document muscle and passive tissue loading-sharing in abduction and axial torsion, and dynamic or novel static optimization approaches that can inherently predict muscle co-contraction. Nonetheless, the predicted joint contact loadings provide estimates that are essentially lower bounds on the likely joint contact loads. Based on our results we suggest that the side-kick and back-kick tasks be modified because the loading levels on the support leg are potentially excessive for the aged arthritic population.     

Adolescent substance abuse treatment outcome: The role of substance abuse problem severity, psychosocial, and treatment factors.

A structural equation model incorporating substance abuse problem severity, psychosocial risk and protection, and treatment variables examined adolescent drug abuse treatment outcome pathways across 6- and 12-month follow-up points. Findings on resiliency factors and an empirical method adapted from previous research were used to select and assign 10 psychosocial factors to either a multiple protective factor index or a risk factor index. Gender, substance abuse problem severity, treatment modality, treatment length, and aftercare participation were also examined as outcome predictors. The findings suggest that treatment intensity decisions may be better informed by pretreatment psychosocial risk level rather than by substance abuse problem severity. The present study also suggests that drug-abusing adolescents who receive sufficiently long treatment, participate in aftercare, and possess at least 1 individual or interpersonal protective factor during their recovery process have the best chance to maintain gains made during treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Weight loss in individuals with metabolic syndrome given DASH diet counseling when provided a low sodium vegetable juice: a randomized controlled trial

Background

Metabolic syndrome, a constellation of metabolic risk factors for type 2 diabetes and cardiovascular disease, is one of the fastest growing disease entities in the world. Weight loss is thought to be a key to improving all aspects of metabolic syndrome. Research studies have suggested benefits from diets rich in vegetables and fruits in helping individuals reach and achieve healthy weights.

Objective

To evaluate the effects of a ready to serve vegetable juice as part of a calorie-appropriate Dietary Approaches to Stop Hypertension (DASH) diet in an ethnically diverse population of people with Metabolic Syndrome on weight loss and their ability to meet vegetable intake recommendations, and on their clinical characteristics of metabolic syndrome (waist circumference, triglycerides, HDL, fasting blood glucose and blood pressure). A secondary goal was to examine the impact of the vegetable juice on associated parameters, including leptin, vascular adhesion markers, and markers of the oxidative defense system and of oxidative stress.

Methods

A prospective 12 week, 3 group (0, 8, or 16 fluid ounces of low sodium vegetable juice) parallel arm randomized controlled trial. Participants were requested to limit their calorie intake to 1600 kcals for women and 1800 kcals for men and were educated on the DASH diet. A total of 81 (22 men & 59 women) participants with Metabolic Syndrome were enrolled into the study. Dietary nutrient and vegetable intake, weight, height, leptin, metabolic syndrome clinical characteristics and related markers of endothelial and cardiovascular health were measured at baseline, 6-, and 12-weeks.

Results

There were significant group by time interactions when aggregating both groups consuming vegetable juice (8 or 16 fluid ounces daily). Those consuming juice lost more weight, consumed more Vitamin C, potassium, and dietary vegetables than individuals who were in the group that only received diet counseling (p < 0.05).

Conclusion

The incorporation of vegetable juice into the daily diet can be a simple and effective way to increase the number of daily vegetable servings. Data from this study also suggest the potential of using a low sodium vegetable juice in conjunction with a calorie restricted diet to aid in weight loss in overweight individuals with metabolic syndrome.     

Optimum Combining in Digital Mobile Radio with Cochannel Interference

This paper studies optimum signal combining for space diversity reception in cellular mobile radio systems. With optimum combining, the signals received by the antennas are weighted and combined to maximize the output signal-to-interference-plus-noise ratio. Thus, with cochannel interference, space diversity is used not only to combat Rayleigh fading of the desired signal (as with maximal ratio combining) but also to reduce the power of interfering signals at the receiver. We use analytical and computer simulation techniques to determine the performance of optimum combining when the received desired and interfering signals are subject to Rayleigh fading. Results show that optimum combining is significantly better than maximal ratio combining even when the number of interferers is greater than the number of antennas. Results for typical cellular mobile radio systems show that optimum combining increases the output signalto-interference ratio at the receiver by several decibels. Thus, systems can require fewer base station antennas and/or achieve increased channel capacity through greater frequency reuse. We also describe techniques for implementing optimum combining with least mean square (LMS) adaptive arrays.     

An experimental and theoretical study of heat and mass transfer during the venting of gas from pressure vessels

Non condensing gas flow and heat transfer during venting of vessels are studied using experiments and analysis. A high pressure helium supply vessel is connected to a low pressure receiver via orifice and tubing. A single control volume analysis and a multi-dimensional analysis are used to predict pressure and mass-averaged temperature in the supply. Experiments utilizing transient PVT methods are conducted to obtain transient pressure and mass-averaged temperature data for validating the analysis. Measured transient pressures and mass-averaged temperatures in the supply are reproduced by analysis. Heat transfer is due to natural convection except for the early part of transfer.     

Spatial-temporal equalization for IS-136 TDMA systems with rapiddispersive fading and cochannel interference

In this paper, we investigate spatial-temporal equalization for IS-136 time-division multiple-access (TDMA) cellular/PCS systems to suppress intersymbol interference and cochannel interference and improve communication quality. This research emphasizes channels with large Doppler frequency (up to 184 Hz), delay dispersion under one symbol duration, and strong cochannel interference. We first present the structure of the optimum spatial-temporal decision-feedback equalizer (DFE) and linear equalizer and derive closed-form expressions for the equalizer parameters and mean-square error (MSE) for the case of known channel parameters. Since the channel can change within an IS-136 time slot, the spatial-temporal equalizer requires parameter tracking techniques. Therefore, we present three parameter tracking algorithms: the diagonal loading minimum MSE algorithm, which uses diagonal loading to improve tracking ability, the two-stage tracking algorithm, which uses diagonal loading in combination with a reduced complexity architecture, and the simplified two-stage tracking algorithm, which further reduces complexity to one M×M and one 3×3 matrix inversion for weight calculation with M antennas. For a four-antenna system, the simplified two-stage tracking algorithm can attain a 10^-2 bit error rate (BER) when the channel delay spread is half of the symbol duration and the signal-to-interference ratio (SIR) of the system is as low as 5 dB, making it a computationally feasible technique to enhance system performance for IS-136 TDMA systems     

Analysis of hybrid selection/maximal-ratio combining in Rayleighfading

We use a novel virtual branch technique to succinctly derive the mean and variance of the combiner output signal-to-noise ratio for hybrid selection/maximal-ratio combining in a multipath-fading environment     

Alcohol Consumption and Intimate Partner Violence by Alcoholic Men: Comparing Violent and Nonviolent Conflicts.

Alcoholic men and their relationship partners were interviewed about a conflict in which physical assault occurred and 1 in which psychological aggression occurred without physical assault. The interview assessed the quantity of alcohol consumed prior to each conflict, other drug use, and the topics, location, timing, duration, and speed of escalation for each conflict. The number of standard drinks consumed by the husband in the previous 12 hr was significantly higher prior to violent versus nonviolent conflicts for both self- and collateral reports, as was blood alcohol concentration estimated from self-report. Other drug use was not significantly different. Greater drinking by wives prior to violent conflicts was found in some analyses. These within-subject comparisons help to rule out individual difference explanations for the alcohol-violence association and indicate that alcohol consumption is a proximal risk factor for partner violence in alcoholic men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)