Bogolyubov approximation for diagonal model of an interacting Bose gas

We study, using the Bogolyubov approximation, the thermodynamic behaviour of a superstable Bose system whose energy operator in the second-quantized form contains a nonlinear expression in the occupation numbers operators. We prove that for all values of the chemical potential satisfying $\mu > \lambda(0)$, where $\lambda (0)\leq 0$ is the lowest energy value, the system undergoes Bose--Einstein condensation

Modelling organic material in activated sludge systems

A simple predictive model for the activated sludge reactor inorganic suspended solids (ISS) concentration is presented. It is based on the accumulation of influent ISS in the reactor and an ordinary heterotrophic organism (OHO) ISS content (fiOHO) of 0.15 mg ISS/mgOHOVSS and a variable phosphate accumulating organism (PAO) ISS content (fiPAO) proportional to their P content (fXBGP). The model is validated with data from 21 investigations conducted over the past 15 years on 30 aerobic and anoxic-aerobic nitrification denitrification (ND) systems and 18 anaerobic-anoxic-aerobic ND biological excess P removal (BEPR) systems variously fed artificial and real wastewater and operated from 3 to 20 d sludge age. The predicted reactor VSS/TSS ratio reflects the observed relative sensitivity to sludge age, which is low, and to BEPR, which is high. For effective use of the model for design, two significant issues require attention: measurement of the influent ISS concentration, which is not commonly done in wastewater characterisation analyses; and estimating a priori the P content of PAOs (fXBGP), which can vary considerably depending on the extent of anoxic P uptake BEPR that takes place in the system. Some guidance on selection of the mixed liquor VSS/TSS ratio for design is given

“Have milk, maas or yoghurt every day”: a food-based dietary guideline for South Africa

A national working group recently reached consensus that a guideline  message for milk consumption should form part of the set of revised food-based dietary guidelines (FBDGs) for South Africa. The message was formulated as: “Have milk, maas or yoghurt every day”. This paper provides scientific support for this FBDG, based on the nutrition and healthprofile of South Africans; addresses concerns about possible detrimental effects of milk consumption, such as lactose intolerance, saturated fat and trans-fat content, milk allergies and dental caries in children; and  identifies barriers to increased consumption. The guideline refers to milk, maas and yoghurt, and not all dairy products. This is based on the nutrient contribution of these products to a healthy diet. Milk (and some dairy products) has a low sodium-to-potassium ratio, as well as bioactive peptides, which may protect against the development of noncommunicable diseases. There is some evidence that the calcium in milk and dairy plays an important role in the regulation of body weight and bone mineral content in children. Available data show that milk and calcium intake in South Africans is low. Identified barriers include perceptions about lactose intolerance, taste, price, lack of knowledge on the nutritive value of milk and milk products, and possibly cultural taboos. As a result, increasing the consumption of milk, maas and yoghurt of South Africans will require active, multifaceted and multilevel promotion

Quantifying benefits of energy efficient house design through monitoring of specified air quality and household energy activity

Energy efficient building design aims to use passive design principles such as orientation, insulation, materials and surrounding area layout to minimise the need for active space heating or cooling. Implementation of the principles of energy efficient design in specifically low-cost houses delivered by government can have numerous benefits such as monetary savings, increased comfort and health indoor environments for homeowners and inhabitants. The project described here measured the indoor air quality of six energy efficient houses in two project areas as well as energy activity and potential benefits related to energy efficient house design. It was concluded that a small reduction in CO2 is achieved in an energy efficient house when compared with a conventional house. However, the reduction achieved is dependent on the type of fuel used for space heating. Overall, the energy efficient houses observed in the project were more comfortable and households spent less on space heating requirements than conventional houses. It is recommended that the principles of energy efficient design should be a minimum requirement in low-cost housing delivery

Granny shows the way: Results from implementing an alternative fire-lighting method in Orange Farm

High levels of air pollution caused by domestic coal burning create human health problems and unwarranted economic loss. The associated health cost is estimated at R1.2 billion per annum. The Basa Njengo Magogo (BNM) alternative fire lighting method represents the highest impact on health from a benefit-cost and employment point of view since the method can potentially reduce ambient air pollution caused by the use of household coal in a relatively short period, by approximately 40-50%. In a pilot study funded by the Department of Minerals and Energy (DME), the method was demonstrated to 16 000 households through a series of direct demonstrations in Orange Farm. The study found that 99% of households who attended a demonstration used the BNM method and continued to use it after a month, households saved on average 25 kilograms of coal, translating in a R26 saving per month. A wide scale implementation of the BNM method holds the potential not only to reduce air pollution but also to result in coal and monetary savings for low-income households

Status of undergraduate community-based and public-health physiotherapy education in South Africa

Curricula of health education institutions therefore need to be periodically revised to be aligned with its context. This study explored the status physiotherapy curricula in South Africa (SA) as point of departure for benchmarking by individual institutions. A document analysis was done of the university physiotherapy departments (N=8) in South Africa. Institutional ethical clearance and permission from the heads of departments were obtained. Content analysis was used to analyse the South African Qualifications Authority exit-level outcomes and the university study guides for community placements. Most universities employed a form of service-learning, with interventions in a range of settings. Five themes emerged: practice of evidence-based physiotherapy, rendering physiotherapy services, acting professionally, communication, and collaboration. The country’s priority conditions were addressed. Teaching-earning strategies included group activities (class or education sessions), community projects, home visits and portfolios of evidence. Personal and small-group reflections were prominent. The undergraduate community physiotherapy curricula in South Africa address the health profile of the population and priorities in the health system to different degrees. The variation between universities should be interpreted with caution as the study guides only gave a limited snapshot into each institution’s curriculum. However, findings suggest that each physiotherapy university department may have gaps in preparing physiotherapy undergraduate students for the needs of the South African population and expectations of the Government. Possible ways to share teaching-learning resources are recommended.Department of HE and Training approved lis

The WKB Approximation without Divergences

In this paper, the WKB approximation to the scattering problem is developed without the divergences which usually appear at the classical turning points. A detailed procedure of complexification is shown to generate results identical to the usual WKB prescription but without the cumbersome connection formulas.Comment: 13 pages, TeX file, to appear in Int. J. Theor. Phy

A model for community physiotherapy from the perspective of newly graduated physiotherapists as a guide to curriculum revision

Background. Limitations in physiotherapy curricula have been reported. Work-based experiences, especially during compulsory community service, could inform curricula. Objective. To develop a model of community service physiotherapy to guide curriculum reform. Methods. In this appreciative inquiry, trained physiotherapy students conducted tele-interviews with newly graduated physiotherapists. Twelve recently graduated community-service physiotherapists – heterogeneous in gender, mother tongue, university attended and work setting – were purposively recruited. Two coders applied Tesch’s coding technique to the transcripts; one did paper-based work and the other used AtlasTi software. Consensus was reached and a member check done. Results. Four themes identified were: (i) the essence of community physiotherapy; (ii) the collaborative nature of community physiotherapy; (iii) prerequisites for a positive practice environment; and (iv) community physiotherapy as a gateway to personal growth and professional development. Physiotherapists consult clients from varied cultural backgrounds, ages and health and disease profiles. Health education is a key intervention, but clients emphasised therapeutic touch. Team work enhances services, especially within a context of poverty, and prevents isolation. New graduates have to deal with inefficient management, lack of transport, inadequate equipment and needs resilience. They want discipline-specific supervision. Conclusion. Community physiotherapy makes specific demands, especially for novice therapists. Service-learning in authentic diverse contexts would foster professional development and cultural competence. Clinical competency should remain the backbone of the curriculum, complemented by competency in health education. Different ways of reflection would facilitate lifelong learning and growth in attributes such as resilience, which is necessary for dealing with sub-optimal practice environments

Instanton approach to the Langevin motion of a particle in a random potential

We develop an instanton approach to the non-equilibrium dynamics in one-dimensional random environments. The long time behavior is controlled by rare fluctuations of the disorder potential and, accordingly, by the tail of the distribution function for the time a particle needs to propagate along the system (the delay time). The proposed method allows us to find the tail of the delay time distribution function and delay time moments, providing thus an exact description of the long-time dynamics. We analyze arbitrary environments covering different types of glassy dynamics: dynamics in a short-range random field, creep, and Sinai's motion.Comment: 4 pages, 1 figur

Errors in drug administration by anaesthetists in public hospitals in the Free State

Objective. To investigate errors in administering drugs by anaesthetists working in public hospitals in the Free State province. Methods. Anonymous questionnaires were distributed to doctors performing anaesthesia in public hospitals in the Free State, i.e. 188 doctors at 22 public sector hospitals. Outcomes included demographic information on respondents, information regarding the administration of anaesthetics, reporting of errors, and the occurrence of errors during anaesthesia. Results. The response rate was 46.3%; 48.8% were medical officers, and 39.3% of participants were involved in at least one event of erroneous drug administration. Registrars and specialists reported the most errors. Most events were of no clinical significance, caused no permanent harm to patients, and most commonly involved fentanyl and suxamethonium. Of the respondents, 23.8% indicated that they were aware of a South African standard for colour-coding syringe labels, and 92.9% indicated that they would report anaesthetic errors if a single reporting agency for such events existed. Conclusions. More than a third of participating anaesthetists were involved in a drug error at some stage in their practice. Preventive systems and precautionary measures should be put in place to reduce drug administration errors