Thermal Behaviour of Euclidean Stars

A recent study of dissipative collapse considered a contracting sphere in which the areal and proper radii are equal throughout its evolution. The interior spacetime was matched to the exterior Vaidya spacetime which generated a temporal evolution equation at the boundary of the collapsing sphere. We present a solution of the boundary condition which allows the study of the gravitational and thermodynamical behaviour of this particular radiating model.Comment: 10 pages, 3 figure

A statistical procedure for validating age estimates from Otolith bands using mark-recapture data, with an illustration for pomatomus saltatrix

A study of age and growth in Pomatomus saltatrix from KwaZulu-Natal was undertaken on the basis of otolith readings. Validation of periodicity of otolith banding was attempted by developing a model that estimated growth parameters from age-length data. The model assumed arbitrarily chosen band-deposition periodicities, and then simultaneously predicted growth increments of tagged individuals based on these growth parameters.The assumption of annual banding led to the best prediction of growth increments of tagged individuals, with small coefficients of variations in the parameter estimates. However, because only a few tagged animals wereused in the analysis, more research is needed to verify the reliability of this technique

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

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

Mortality estimates for juvenile dusky sharks carcharhinus Obscurus in South Africa using mark-recapture data

A maximum likelihood model is developed, using mark-recapture data, to estimate total and fishing mortality rates for the dusky shark Carcharhinus obscurus in South Africa. The model accounts for tag-shedding, nonreportingof recaptured tags, the multiple release and single recapture nature of the study and the usage of two different types of tags (sheep-ear and ORI tags). Tag shedding was quantified as tags washed up on beaches andfouling of tags in protective shark nets, which amounted to 17% of all tags recovered between 1986 and 1993. The ORI tag had a higher tag-shedding rate than the sheep-ear tag. Assuming a 75% reporting rate for recaptureddusky sharks, an instantaneous fishing mortality rate was estimated to be 0.27.year–1, with a 95% confidence level ranging between 0.19 and 0.44.year–1

Characterization of 1,2-dichloroethane (DCA) degrading bacteria isolated from South African waste water

1,2-Dichloroethane (DCA), a potential carcinogen that is toxic to both terrestrial and aquatic ecosystems, is one of the most widely produced chemicals in the modern world. It is used as a metal degreaser, solvent, chemical intermediate and fuel additive. Contamination of the environment with DCA results from accidental spills and poor handling. To date, several bacterial isolates, capable of utilizing this compound as a sole carbon and energy source, have been identified in the northern hemisphere. This report focused on the isolation and characterization of bacterial isolates in the southern hemisphere that are capable of degrading DCA. Samples obtained from a waste water treatment plant in Durban, South Africa were batch cultured in minimal medium containing DCA and repeatedly sub-cultured every five days over a 25 day period. A halogen release assay was performed in order to determine whether individual isolates possessed dehalogenase activity. Confirmation of DCA utilization by bacterial isolates that were positive for dehalogenase activity was done by sub-culturing back into minimal medium containing DCA. It was found that five isolates possessed an identical hydrolytic dehalogenase gene following the design of primers based on known hydrolytic dehalogenase genes. Analysis of 16S rDNA sequences indicated that, all the South African isolates belonged to the genus Ancylobacter and were different from each other.Key words: 1,2- dichloroethane, halogenated hydrocarbon, xenobiotic, dehalogenase

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

A Conceptual Overview Of The Impact Of Covid-19 On E-Commerce Among Small And Medium Enterprises In South Africa

SMEs are fundamental participants in a global landscape, especially in emerging economies like South Africa. During the Covid-19 pandemic, SMEs had to move their business online, due to lockdown regulations and fear of contracting the deadly virus. The sudden need to utilize e-commerce amongst SMEs became a major challenge, since many SMEs grappled with one or more of the four elements to complete e-commerce transactions, namely, access to reliable broadband, e-shop of products and services, digital payment, and logistics to the consumer. Thus, this conceptual paper attempts to understand the impact of the above elements of an e-commerce transaction on e-commerce growth among SMEs in South Africa. Following an in-depth literature review, eight (8) research propositions were developed pustulating relationships between the four elements of an e-commerce transaction and e-commerce growth

E-Commerce Challenges of SMMEs In South Africa During the Covid-19 Pandemic

During the Covid-19 pandemic, small and medium-sized enterprises (SMEs) have had to shift business operations to online, due to the lockdown protocols and government restrictions. The sudden need by SMEs to change the operations model to e-commerce, became a major challenge. Many SMEs were challenged by one or more of the four e-commerce resources to complete an e-commerce transaction, namely usage of reliable broadband, e-shop of products and services, digital payment, and logistics to the consumer. Thus, this study investigated the challenges experienced by SMEs when using e-commerce platforms during the Covid-19 pandemic. Through an extensive literature review, several hypotheses were postulated and data was collected from SME owners in Gauteng Province, South Africa to test them. Simple random sampling was used to identify participants for the survey and the questionnaires which were adaptation of previously developed ones were distributed via email to 307 retail SMEs in Edenvale, Gauteng. Inferential statistical analysis, through structural equation modelling, was used to analyse the data that was collected through the survey. The findings revealed that digital payments and logistics were significant predictors of e-commerce growth during the pandemic and dynamic skill capabilities moderated the relationship between digital payments and e-commerce growth. However, the usage of broadband and e-shop features were not significant in predicting the growth of e-commerce

An investigation into the challenges and limitations of implementing universal pulse oximetry screening for critical congenital heart disease in asymptomatic newborns

Neonatal pulse oximetry has been identified as an important screening tool for critical congenital heart disease. This oximetry screening, although mandatory in many developed countries, is not routinely implemented in South African hospitals.The objective of this study was therefore to determine the feasibility of implementing pulse oximetry in a typical level 2 hospital in the province of KwaZulu-Natal. Challenges and limitations experienced in implementing the screening were documented.The study was an observational analytical descriptive study which was conducted in the postnatal ward of Addington Hospital, Durban. Nursing staff were educated regarding the importance of pulse oximetry screening and were subsequently trained to perform the procedure.A total of 2 453 newborns were admitted to the hospital from January to August 2016 with 599 of these being eligible for enrolment in the study. Consent and screening were initially performed by participating nursing staff. During the last 4 months, consent was obtained by a dedicated research assistant. Of the 599 eligible newborns, 22 were excluded resulting in 577 being available for analysis. There were 29 newborns who fulfilled criteria for a second screening, however, in 21 of these newborns, the protocol was not appropriately followed.This study suggests that while routine neonatal saturation monitoring appears to be a simple, cost-effective tool to detect critical congenital heart disease, several barriers to its implementation were detected. The main barriers were inadequate staffing and infrastructure. This, in turn, highlighted the need for appropriate human resource provision and training as well as adequate infrastructure. These may not be easily achievable in a resource constrained environment