Computation of thermochemical nonequilibrium flows around a simple and a double ellipse

The nonequilibrium viscous reactive flows over a simple and a double ellipse at a 30 degree angle of attack were computed. The geometry and the free stream conditions are given by INRIA/GAMNI/SMAI workshop test cases 6.2-2 and 6.2-4. The governing Navier-Stokes equations coupled with thermochemical nonequilibrium processes are solved numerically using a fully coupled, implicit, finite volume technique with a dynamically adaptive grid. The nonequilibrium gas model and the numerical method used in the calculations are briefly described

An inventory of the South african fitness industry

Objective. The aim of this study was to create an inventory of fitness facilities in South Africa, their location, equipment and services offered, and the demographics, education and training of the staff working in these facilities. Design. A total of 750 facilities were identified, and descriptive data were gathered from 442 facilities (59%) with the use of a questionnaire administered telephonically and via the website of the Sports Science Institute of South Africa. Setting. The study was initiated by the Sports Science Institute, and the results were presented at the 4th Annual Discovery Vitality Fitness Convention on 4 May 2006. Results. Results show that the industry comprises mainly independent facilities (68%). All types of facilities were found to be located mostly within urban areas, and reported providing services to just less than 2% of the South African population. Facilities offer a wide range of equipment and services to their members. Of the fitness-related staff at facilities, the majority were reported to be young (18 - 25 years, 55% of male, and 49% of female staff), and in terms of racial proportions most staff were white (males 40% of total staff and females 33% of total staff).Less than a quarter of fitness-related staff hold university qualifications, and just over 80% of instructors hold qualifications aligned with the National Qualifications Framework. The importance of education and training of staff was emphasised by respondents. Conclusions. This report highlights the widespread value of assessing the fitness industry, particularly within the context of the rise of chronic diseases in South Africa and government initiatives to promote healthy lifestyles. South African Journal of Sports Medicine Vol. 18 (3) 2006: pp. 93-10

The association between nutrition and physical activity knowledge and weight status of primary school educators

The purpose of this study was to investigate primary school educators’ health status, knowledge, perceptions and behaviour regarding nutrition and physical activity.Thus, nutrition and physical activity knowledge, attitudes,  behaviour and risk factors for the development of non-communicable diseases of 155 educators were assessed in a  cross-sectional survey. Height, weight, waist circumference, blood pressure and random glucose levels were  measured. Twenty percent of the sample had normal weight (body mass index (BMI, kg/m²) &lt; 25), 27.7% were  overweight (BMI 25 to < 30) and 52.3% were obese (BMI < 30). Most of the participants were younger than 45  years (54.2%), females 78.1%, resided in urban areas (50.3%), with high blood pressure ( 140/90 mmHg:  50.3%), and were inactive (48.7%) with a high waist circumference (&gt; 82 cm: 57.4%). Educators’ nutrition and  physical activity knowledge was poor. Sixty-nine percent of educators incorrectly believed that eating starchy foods  causes weight gain and only 15% knew that one should eat five or more fruit and/or vegetables per day. Aspects of poor nutritional knowledge, misconceptions regarding actual body weight status, and challenges in changing health behaviours, emerged as issues which need to be addressed among educators. Educators’ high risk for developing chronic non-communicable diseases (NCDs) may impact on educator absenteeism and subsequently on school  functioning. The aspects of poor nutrition and physical activity knowledge along with educators’ high risk for NCD development may be particularly significant not merely in relation to their personal health but also the learners they teach.Keywords: body weight, educators, health, knowledge, non-communicable diseases, nutrition, perceptions, physical activity, primary schools, risk factor

Maternal and early life nutrition and physical activity: setting the research and intervention agenda for addressing the double burden of malnutrition in South African children.

Early life is important for later health outcomes, yet there are few studies which adequately address all of the potential early life insults that may affect later life health and growth trajectories. This is particularly evident in low- to middle-income countries such as South Africa, where women of childbearing age are particularly vulnerable to high levels of physical inactivity, malnutrition, and obesity. Pregnancy may therefore be an opportune time to change behaviours and improve maternal and offspring health outcomes, and decrease the inter-generational transfer of risk. We show clear evidence that physical activity and nutrition are important target areas for intervention during pregnancy and in the early years of life, yet that current literature in Africa, and specifically South Africa, is limited. We have outlined the available literature concerning the impact of maternal and early life nutrition and physical activity on the health status of South African children, and have provided some recommendations for future research and policy

An inventory of the South african fitness industry

Objective. The aim of this study was to create an inventory of fitness facilities in South Africa, their location, equipment and services offered, and the demographics, education and training of the staff working in these facilities. Design. A total of 750 facilities were identified, and descriptive data were gathered from 442 facilities (59%) with the use of a questionnaire administered telephonically and via the website of the Sports Science Institute of South Africa. Setting. The study was initiated by the Sports Science Institute, and the results were presented at the 4th Annual Discovery Vitality Fitness Convention on 4 May 2006. Results. Results show that the industry comprises mainly independent facilities (68%). All types of facilities were found to be located mostly within urban areas, and reported providing services to just less than 2% of the South African population. Facilities offer a wide range of equipment and services to their members. Of the fitness-related staff at facilities, the majority were reported to be young (18 - 25 years, 55% of male, and 49% of female staff), and in terms of racial proportions most staff were white (males 40% of total staff and females 33% of total staff).Less than a quarter of fitness-related staff hold university qualifications, and just over 80% of instructors hold qualifications aligned with the National Qualifications Framework. The importance of education and training of staff was emphasised by respondents. Conclusions. This report highlights the widespread value of assessing the fitness industry, particularly within the context of the rise of chronic diseases in South Africa and government initiatives to promote healthy lifestyles. South African Journal of Sports Medicine Vol. 18 (3) 2006: pp. 93-10

Towards Compound Identification of Synthetic Opioids in Non-targeted Screening Using Machine Learning Techniques.

The constant evolution of the illicit drug market makes the identification of unknown compounds problematic. Obtaining certified reference materials for a broad array of new analogues can be difficult and cost prohibitive. Machine learning provides a promising avenue to putatively identify a compound before confirmation against a standard. In this study, machine learning approaches were used to develop class prediction and retention time prediction models. The developed class prediction model used a Naïve Bayes architecture to classify opioids as belonging to either the fentanyl analogues, AH series or U series, with an accuracy of 89.5%. The model was most accurate for the fentanyl analogues, most likely due to their greater number in the training data. This classification model can provide guidance to an analyst when determining a suspected structure. A retention time prediction model was also trained for a wide array of synthetic opioids. This model utilised Gaussian Process Regression to predict the retention time of analytes based on multiple generated molecular features with 79.7% of the samples predicted within ± 0.1 min of their experimental retention time. Once the suspected structure of an unknown compound is determined, molecular features can be generated and input for the prediction model to compare with experimental retention time. The incorporation of machine learning prediction models into a compound identification workflow can assist putative identifications with greater confidence and ultimately save time and money in the purchase and/or production of superfluous certified reference materials

On the use of the group SO(4,2) in atomic and molecular physics

In this paper the dynamical noninvariance group SO(4,2) for a hydrogen-like atom is derived through two different approaches. The first one is by an established traditional ascent process starting from the symmetry group SO(3). This approach is presented in a mathematically oriented original way with a special emphasis on maximally superintegrable systems, N-dimensional extension and little groups. The second approach is by a new symmetry descent process starting from the noninvariance dynamical group Sp(8,R) for a four-dimensional harmonic oscillator. It is based on the little known concept of a Lie algebra under constraints and corresponds in some sense to a symmetry breaking mechanism. This paper ends with a brief discussion of the interest of SO(4,2) for a new group-theoretical approach to the periodic table of chemical elements. In this connection, a general ongoing programme based on the use of a complete set of commuting operators is briefly described. It is believed that the present paper could be useful not only to the atomic and molecular community but also to people working in theoretical and mathematical physics.Comment: 31 page

Delayed retinal vein recovery responses indicate both non-adaptation to stress as well as increased risk for stroke: the SABPA study

OBJECTIVES: Low or high sympatho-adrenal-medullary axis (SAM) and hypothalamic-pituitary-adrenal axis (HPA) dysregulation reflect chronic stress. Retinal vessel dynamics may relate to SAM, HPA activity and stroke risk. Our objectives were therefore to assess the relationships between retinal vessel, SAM and HPA responses, and to determine stroke risk. METHODS: A prospective bi-ethnic gender cohort (n = 275, 45 ± 9 years) was included. Urine/serum/saliva samples for SAM [norepinephrine:creatinine ratio (u-NE)] and HPA [adrenocorticotrophic hormone (ACTH), cortisol] were obtained at baseline, three-year follow up and upon flicker light-induced provocation. Diastolic ocular perfusion pressure was measured as a marker of hypo-perfusion. Retinal arterial narrowing and venous widening calibres were quantified from digital images in the mydriatic eye. A validated stress and stroke risk score was applied. RESULTS: An interaction term was fitted for venous dilation in u-NE tertiles (p ≤ 0.05) and not in u-NE median/quartiles/quintiles. Independent of race or gender, tertile 1 (low u-NE) had a 112% increase in u-NE, decreases in cortisol, and no changes in ACTH over three years (positive feedback). Tertile 3 (high u-NE) contradictorily had decreases in u-NE and cortisol, and increases in ACTH (negative feedback). In tertile 1, reduced arterial dilation, and faster arterial vasoconstriction and narrowing were related to higher SAM activity and hypo-perfusion (p ≤ 0.05), whereas delayed venous dilation, recovery and widening were related to cortisol hypo-secretion (p ≤ 0.05). In tertile 1, delayed venous recovery responses predicted stress and stroke risk [odds ratio 4.8 (1.2-19.6); p = 0.03]. These associations were not found in u-NE tertiles 2 and 3. CONCLUSIONS: In response to low norepinephrine, a reflex increase in SAM activity occurred, enhancing arterial vasoconstriction and hypo-perfusion. Concomitant HPA dysregulation attenuated retinal vein vasoactivity and tone, reflecting delayed vein recovery responses and non-adaptation to stress. These constrained vein recovery responses are indicative of increased chronic stress and stroke risk

Evaluation of a school-based physical activity intervention in Alexandra Township

Objectives. Non-communicable diseases and limited participation in school physical education have become increasing concerns in South Africa. In response to these concerns, a schoolbased physical activity intervention, Healthnutz, was implemented in three primary schools in Alexandra Township, Johannesburg. Evaluation of Healthnutz included assessing its feasibility and acceptability, and short-term changes in learners’ physical fitness, knowledge and attitudes. Methods. To assess feasibility and acceptability, a situational analysis and focus groups with teachers and programme monitors were conducted. Pre-post fitness testing (3-month interval) was conducted with learners, and a questionnaire assessed changes in learners’ knowledge, attitudes, self-efficacy, and perceived barriers to physical activity, in control and intervention schools. Results. At implementation, teachers identified the need for more physical activity in the school environment and were positive about Healthnutz. Follow-up focus group discussions suggested that it was positively impacting teachers, learners and the school in general. Scores for sit and reach (p&lt;0.001), sit ups (p&lt;0.02) and shuttle run (p&lt;0.0001) improved significantly in intervention but not control schools. A significant decrease was observed in learners’ perceived external barriers to physical activity (p&lt;0.0001) along with a positive change in learners’ self-efficacy for physical activity (p&lt;0.05). Conclusions. Healthnutz raised awareness of the importance of physical activity in intervention schools. Findings indicate that even limited exposure to a physical activity intervention can lead to a significant improvement in aspects of learners’ fitness, knowledge, attitudes and perceptions regarding physical activity. Furthermore, training and support of teachers needs to be nonjudgemental and empowering

Bayesian Hierarchical Models Combining Different Study Types and Adjusting for Covariate Imbalances: A Simulation Study to Assess Model Performance

BACKGROUND: Bayesian hierarchical models have been proposed to combine evidence from different types of study designs. However, when combining evidence from randomised and non-randomised controlled studies, imbalances in patient characteristics between study arms may bias the results. The objective of this study was to assess the performance of a proposed Bayesian approach to adjust for imbalances in patient level covariates when combining evidence from both types of study designs. METHODOLOGY/PRINCIPAL FINDINGS: Simulation techniques, in which the truth is known, were used to generate sets of data for randomised and non-randomised studies. Covariate imbalances between study arms were introduced in the non-randomised studies. The performance of the Bayesian hierarchical model adjusted for imbalances was assessed in terms of bias. The data were also modelled using three other Bayesian approaches for synthesising evidence from randomised and non-randomised studies. The simulations considered six scenarios aimed at assessing the sensitivity of the results to changes in the impact of the imbalances and the relative number and size of studies of each type. For all six scenarios considered, the Bayesian hierarchical model adjusted for differences within studies gave results that were unbiased and closest to the true value compared to the other models. CONCLUSIONS/SIGNIFICANCE: Where informed health care decision making requires the synthesis of evidence from randomised and non-randomised study designs, the proposed hierarchical Bayesian method adjusted for differences in patient characteristics between study arms may facilitate the optimal use of all available evidence leading to unbiased results compared to unadjusted analyses