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

The Adoption of Internet Banking in a Developing Economy

The international world has witnessed significant developments in internet banking. This has presented opportunities to both banks and customers in the world of e-commerce. The adoption rate for internet banking in South Africa has been low, compared to other developing countries. With a reasonably well developed infrastructure, South Africa presents itself with great market potential for internet banking. Given this scenario, this paper examines the factors influencing the adoption of internet banking in South Africa. A survey was conducted using a sample of 400 consumers using a quantitative and descriptive design. The results indicate a relationship between the selected biographical variables and the adoption of internet banking. Perceived usefulness, an indicator of relative advantage was associated with the adoption of internet banking. Users considered internet banking to be less complex and less costly than non-users. It emerged that both users and non-users did not consider social influences as being a factor in the adoption of internet banking

The quadriceps angle and the incidence of knee injury in Indian long-distance runners

Objective. To investigate the incidence of knee injuries in runners and to determine the proportion of injuries involving abnormal quadriceps (Q)-angles. Design. One hundred male Indian runners between the ages of 25 and 65 years from 5 athletic clubs in Durban volunteered to participate in the study. The Q-angle was measured using a goniometer. Other relevant information was obtained using a validated questionnaire. The data were analysed by comparing measured Q-angles with ‘normal' values of Q-angles obtained from the literature. A paired t-test at a probability of 0.05 was used. Setting. Data were collected at club meetings. Main outcome measure. The primary outcome of the study was to determine the proportion of runners with abnormal Q-angles. Thereafter the rate of knee injuries in runners with abnormal Q-angles was determined. Results. Data from 88 runners were usable. Fifty-one per cent of the runners sustained knee injuries. Fifty-eight per cent of the sample had abnormal Q-angles. Sixty-seven per cent of the runners with abnormal Q-angles sustained knee injuries. Conclusion. More runners with abnormal Q-angles sustained knee injuries. There is a need to determine reference values for Q-angles for the South African population, the proportion of the population that present with abnormal Q-angles, and the reasons for this. South African Journal of Sports Medicine Vol. 19 (1) 2007: pp. 9-1

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

Diagnostic outcome of patients referred to psychiatry with medically unexplained symptoms: a retrospective study

Objective: Medically unexplained symptoms (MUS) are commonly encountered in medical practice. In psychiatry, they are classified mostly as Somatoform Disorders and are often associated with anxiety and depression. The literature suggests that, in some cases, MUS may be ascribed to Somatoform Disorders when, fact, they are “organic” syndromes that are misdiagnosed. In developing countries, with fewer resources, MUS may be more difficult to assess. Method: We undertook a retrospective chart review to examine the demographics, referral pathway, management and diagnostic outcome of subjects (n = 50) referred to psychiatry with MUS over an 18 month period. Results: Subjects with MUS accounted for only 4.5% of the total number of files reviewed. In only 38% of cases did the final diagnosis in psychiatry concur with the referral diagnosis. In 28% of cases a new “organic” diagnosis was made and in 72% of cases a new psychiatric diagnosis was made. Subjects who were diagnosed with “organic” illness were seen fewer times prior to referral to psychiatry and were significantly older than other subjects. Conclusion: In developing countries like SA, a significant number of patients with MUS may have underlying “organic” illness, and most may have psychiatric disorders. Patients with MUS, especially older patients, should be more extensively investigated. Psychiatric referral of these patients is very appropriate.Keywords: Medically unexplained symptoms; Psychiatric disorders; Retrospective review; Somatoform disorder

International Students’ Expectations and Perceptions of Service Quality: The Case of a Higher Education Institution in South Africa

South Africa has recently seen a significant increase in international student enrolments in recent years. In order to be competitive, attention needs to be given to service quality with a view to being the institution of preference. This paper therefore seeks to assess international students’ expectations and perceptions of service quality. A census was conducted among the 215 international students, using the SERVQUAL model as the measuring instrument. The results indicate that there are gaps between international students’ expectations and perceptions on the five service quality dimensions. An analysis of variance was conducted to test for significant differences between three biographical variables viz. faculty of study, qualification enrolled for and region of residence versus the five dimensions of service quality, on both expectations and perceptions. Recommendations are presented on how the institution can enhance service quality among its international students

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

Diagnostic outcome of patients referred to psychiatry with medically unexplained symptoms: a retrospective study

Objective: Medically unexplained symptoms (MUS) are commonly encountered in medical practice. In psychiatry, they are classified mostly as Somatoform Disorders and are often associated with anxiety and depression. The literature suggests that, in some cases, MUS may be ascribed to Somatoform Disorders when, fact, they are “organic” syndromes that are misdiagnosed. In developing countries, with fewer resources, MUS may be more difficult to assess. Method: We undertook a retrospective chart review to examine the demographics, referral pathway, management and diagnostic outcome of subjects (n = 50) referred to psychiatry with MUS over an 18 month period. Results: Subjects with MUS accounted for only 4.5% of the total number of files reviewed. In only 38% of cases did the final diagnosis in psychiatry concur with the referral diagnosis. In 28% of cases a new “organic” diagnosis was made and in 72% of cases a new psychiatric diagnosis was made. Subjects who were diagnosed with “organic” illness were seen fewer times prior to referral to psychiatry and were significantly older than other subjects. Conclusion: In developing countries like SA, a significant number of patients with MUS may have underlying “organic” illness, and most may have psychiatric disorders. Patients with MUS, especially older patients, should be more extensively investigated. Psychiatric referral of these patients is very appropriate.Keywords: Medically unexplained symptoms; Psychiatric disorders; Retrospective review; Somatoform disorder