Radiating Collapse with Vanishing Weyl stresses

In a recent approach in modelling a radiating relativistic star undergoing gravitational collapse the role of the Weyl stresses was emphasised. It is possible to generate a model which is physically reasonable by approximately solving the junction conditions at the boundary of the star. In this paper we demonstrate that it is possible to solve the Einstein field equations and the junction conditions exactly. This exact solution contains the Friedmann dust solution as a limiting case. We briefly consider the radiative transfer within the framework of extended irreversible thermodynamics and show that relaxational effects significantly alter the temperature profiles.Comment: 10 pages, submitted to IJMP-

The role of shear in dissipative gravitational collapse

In this paper we investigate the physics of a radiating star undergoing dissipative collapse in the form of a radial heat flux. Our treatment clearly demonstrates how the presence of shear affects the collapse process; we are in a position to contrast the physical features of the collapsing sphere in the presence of shear with the shear-free case. By employing a causal heat transport equation of the Maxwell-Cattaneo form we show that the shear leads to an enhancement of the core temperature thus emphasizing that relaxational effects cannot be ignored when the star leaves hydrostatic equilibrium.Comment: 15 pages, To appear in Int. J. Mod. Phys.

The effect of a two-fluid atmosphere on relativistic stars

We model the physical behaviour at the surface of a relativistic radiating star in the strong gravity limit. The spacetime in the interior is taken to be spherically symmetrical and shear-free. The heat conduction in the interior of the star is governed by the geodesic motion of fluid particles and a nonvanishing radially directed heat flux. The local atmosphere in the exterior region is a two-component system consisting of standard pressureless (null) radiation and an additional null fluid with nonzero pressure and constant energy density. We analyse the generalised junction condition for the matter and gravitational variables on the stellar surface and generate an exact solution. We investigate the effect of the exterior energy density on the temporal evolution of the radiating fluid pressure, luminosty, gravitational redshift and mass flow at the boundary of the star. The influence of the density on the rate of gravitational collapse is also probed and the strong, dominant and weak energy conditions are also tested. We show that the presence of the additional null fluid has a significant effect on the dynamical evolution of the star.Comment: 31 pages, Minor corrections implemente

Knowledge of primary school teachers about asthma: a cross-sectional survey in the Umdoni sub-district, KwaZulu-Natal

Background: Asthma is one of the most common chronic respiratory conditions affecting young children. It is estimated that asthma affects 20% of schoolchildren in South Africa. The school setting represents “home” for most children, and teachers are recognised as in loco parentis. Therefore, it is imperative that primary school teachers have sufficient knowledge of asthma and its management, in order to be able to make rational and safe decisions about the children in their care. This study was undertaken to assess the levels of asthma knowledge and its  management among primary school teachers.Method: Data were collected from 226 consenting schoolteachers in 19 randomly selected primary schools in the Umdoni sub-district of KwaZulu-Natal, using a cellular telephone Mobile Researcher® application. A total of 55 questions relating to knowledge of asthma were posed, together with questions about motivation for, and confidence in managing, an asthmaemergency.Results: Overall, 38.5% of teachers were able to answer < 50% of the knowledge questions correctly. Teachers’ level of asthma knowledge was not significantly associated with age, gender, years of teaching experience, educational qualification, or contact with an asthmatic individual (p-value = 0.153, p-value = 0.870, p-value = 0.070, p-value = 0.082 and p-value =0.176, respectively). Areas of particular concern included knowledge  regarding the signs and symptoms of a severe acute asthma attack, asthma medication and management, and asthma and sports.Conclusion: This study demonstrates deficiencies in teachers’ knowledge of asthma, which will need to be addressed if they are to safely discharge their duty of care. Teachers are supportive of in-service training in asthma management

Promoting patient autonomy: Perspectives of occupational therapists and nurses

Background. There has been a turn in the last decade towards autonomy in patient care. Promoting patient autonomy is required as a collaborative endeavour between the patient, healthcare professionals and the families and caregivers of patients. Our current discourse demonstrates patient autonomy as essential.Objective. To explore the concept of autonomy in nurses’ and occupational therapists (OTs)’ individual and collective practice as healthcare professionals.Methods. The study followed a qualitative explorative approach. Fourteen nurses and 12 OTs from 6 facilities in KwaZulu-Natal Province of South Africa were recruited into the study. Following ethical approval, and dependent on the availability of participants, data were collected via focus groups, triad and individual semi-structured interviews and qualitative questionnaires. Data were analysed using inductive thematic analysis per profession initially, and then later merged to develop themes.Results. Two major themes emerged that spoke to the deconstruction of autonomy and deterrents to the promotion of autonomy in clinical practice. An individualistic view of autonomy was embedded within the participants’ understanding of the concept. It included the patient’s right and ability to selfdetermine or direct treatment and various interventions, having appropriate guidance and the relevant information to make  decisions, and opportunities to self-determine their course of treatment. Patient-related and organisational factors served as barriers to the promotion of autonomy.Conclusion. By analysing the experiences of autonomy in practice of these two professions, we may be able to establish new ways of understanding how professional practice can truly become patient-centred and transition from an individualistic understanding of autonomy towards viewing autonomy as relational

Sharps disposal practices among diabetic patients using insulin

Insulin-dependent diabetic patients are not educated on safe sharps disposal methods, so leading to unsafe disposal of needles. Appropriate education on the correct disposal of sharps should be an integral part of their diabetic counseling. Doctors, nurses and pharmacists should all take responsibility for educating and reinforcing information about correct sharps disposal methods. Patients should be advised to either discard sharps into punctureresistant containers placed into their household refuse, or return them in secure containers for disposal by the dispensing institutions. Patients should also be educated regarding health risks associated with used needles. The South African Metabolic and Endocrine (SEMDSA) Guidelines and the South African Standard Treatment Guidelines (STG) should also give clear guidance on the safe disposal of needles

Predictors of Peri-Operative Risk Acceptance by South African Vascular Surgery Patients at a Tertiary Level Hospital

Background: Vascular surgical patients have an elevated cardiac risk following non-cardiac surgery. The decision whether to proceed with surgery is multidimensional. Patients must balance the considerations in favour of surgery with those favouring conservative treatment, which requires weighing peri-operative risk against morbidity associated with non-surgical treatment.Methods: The aim of this prospective correlational study was to determine the proportional contributions of (i) pain, (ii) impulsivity, (iii) patients’ perception of the benefits of surgery, (iv) patients’ perception of peri-operative risk and (v) the predicted peri-operative risk on acceptance of peri-operative risk by vascular surgical patients. Sixty patients were prospectively recruited by convenience sampling from the Inkosi Albert Luthuli Central Hospital vascular surgery clinic between April 2014 and June 2014. Written informed consent was obtained. Patients completed a questionnaire which documented demographics, pain assessment, impulsivity screen (Barratt Impulsiveness Scale 11), patients’ perception of surgery, predicted peri-operative risk (South African Vascular Surgical Cardiac Risk Index) and acceptance of peri-operative risk. Data were analysed using descriptive statistics and linear regression (SPSS version 22).Results: The patients’ perception of the benefits of surgery (β 0.36, 95% CI 0.14–0.70, p = 0.005) was the only predictor of peri-operative risk acceptance. The associations between the other potential predictors and the outcome were insignificant.Conclusion: The perceived benefit of surgery was the most important predictor of acceptance of peri-operative risk in this cohort.Keywords: Pain, Peri-operative Risk, Shared Decision-making, Vascular Surger

Radiating spherical collapse with heat flow

We present here a simple model of radiative gravitational collapse with radial heat flux which describes qualitatively the stages close to the formation of a superdense cold star. Starting with a static general solution for a cold star, the model can generate solutions for the earlier evolutionary stages. The temporal evolution of the model is specified by solving the junction conditions appropriate for radiating gravitational collapse.Comment: 13 pages, including 3 figures, submitted to IJMP-