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In this work we take our cue from the observations of gravitational waves of the GW190814 event which suggests that source of the signals can be ascribed to a compact binary coalescence of a 22.2 to 24.3$ M_{\odot}$ black hole and a compact object endowed with a mass of 2.50 to 2.67$M_{\odot}$. In the current exposition, we are concerned with modeling of the lower mass component of the coalescence pair. We utilise the $f(\mathcal{Q})$ gravity together with Minimum Geometric Deformation (MGD) technique to obtain compact stellar objects with masses aligned with the GW190814 event. Starting off with the Tolman IV ansatz for one of the metric functions, together with a MIT Bag model equation of state we are able to reduce the problem of fully describing the gravitational behaviour of the seed solution to a quadrature. Through the MGD technique, we introduce anisotropy by deforming the radial part of the gravitational potential. This enables us to obtain two new classes of solutions which depend on the metricity parameter, $\cal Q$ and the deformation constant, $\beta$. We show that these two parameters play a crucial role in determining the thermodynamical behaviour and stability of our models. In particular, we show that the interplay between the metricity parameter and the deformation constant leads to predicted mass of the progenitor articulating as the secondary component of GW190814., Comment: 11 Figures and 3 Tables

In this paper, we discuss the Bianchi type-I cosmological model in the framework of symmetric teleparallel gravity say $f(Q)$ gravity in which the non-metricity term $Q$ is responsible for the gravitational interaction. We consider a special form of the $f\left( Q\right) $ function which can be cast as $f\left( Q\right) =\lambda Q^{n}$, where $\lambda $ and $n$ both are the dynamical model parameters. Such a choice can be viewed as a hybrid scale factor that leads to a relation between cosmic time and redshift as $% t=\left( \frac{\alpha t_{0}}{\beta }\right) W\left[ \frac{\beta }{\alpha }e^{% \frac{\beta -\ln \left( 1+z\right) }{\alpha }}\right] $ which describes a $% \Lambda $CDM model of the Universe with the expansion evolving from decelerating to an acceleration phase. The best values for the model parameters i.e. $\alpha $ and $\beta $ that would accord with the most current observational datasets are then estimated. We make use of 57 points from the Hubble dataset, 1048 points from the supernovae of type Ia dataset and 6 points from the BAO dataset. We use the Markov Chain Monte Carlo (MCMC) technique in conjunction with Bayesian analysis and the likelihood function. Further, we study the validity of our model with the investigation of the thermodynamical quantities, energy conditions along with some physical variables such as the EoS, and jerk parameters. Next, our results are discussed in light of current observational data and trends., Comment: Journal of High Energy Astrophysics accepted version

In this exposition, we seek solutions of the Einstein-Maxwell field equations in the presence of a massive scalar field cast in the Brans-Dicke (BD) formalism which describes charged anisotropic strange stars. The interior spacetime is described by a spherically symmetric static metric of embedding class I. This reduces the problem to a single-generating function of the metric potential which is chosen by appealing to physics based on regularity at each interior point of the stellar interior. The resulting model is subjected to rigorous physical checks based on stability, causality and regularity. We show that our solutions describe compact objects such as PSR J1903+327; Cen X-3; EXO 1785-248 \& LMC X-4 to an excellent approximation. Novel results of our investigation reveal that the scalar field leads to higher surface charge densities which in turn affects the compactness and upper and lower values imposed by the modified Buchdahl limit for charged stars. Our results also show that the electric and scalar fields which originate from entirely different sources couple to alter physical characteristics such as mass-radius relation and surface redshift of compact objects. This superposition of the electric and scalar fields is enhanced by an increase in the BD coupling constant, $\omega_{BD}$., Comment: 9 figures and 6 tables

Background. Notification of occupational diseases to the Department of Labour (and in limited situations to other agencies) is an important aspect of surveillance and planning for interventions as well as compensation. A survey of general practitioners (GPs) was conducted to assess their knowledge and practice with regard to reporting of occupational diseases.Design. Descriptive telephonic survey.Setting. Independent general practices in the Western Cape.Participants. One hundred and forty GPs were randoinly selected from a provincial sampling frame of 1 000 GPs.Main outcome measures. Knowledge of notification procedures for occupational diseases, and problems encountered with the reporting system.Results. Of a total of 109 GPs interviewed, 75% had diagnosed more than one case of occupational disease in the last 6 months. Twenty-four per cent of the total (95% confidence interval (0) 16 - 32%) indicated that they were aware of the notification requirements, and 5% (95% Cl 0.8 9%) knew the appropriate legislation. Only one GP notified the appropriate authority once the diagnosis was made. Factors influencing their reporting practice included lack of guidelines for diagnosis of common work-related conditions, lack of information regarding referral channels, problems with communicating with the patient and employer, and poor knowledge of the reporting process itself. Lack of motivation as a result of poor feedback on cases reported and the labour-intensive administration required, were also cited as factors.Conclusion. Although the majority of GPs diagnose occupational diseases, knowledge and practice regarding notification are poor. Recommendations to overcome obstacles to notification include a simplified, uniform notification system, adequate training and support of GPs, and timeous feedback to GPs.

Rectus sheath haematoma (RSH) is an uncommon cause of acute abdominal pain, but can mimic a variety of acute surgical conditions. Computed tomography (CT) provides the diagnosis and avoids unnecessary procedures.

Rectus sheath haematoma (RSH) is an uncommon cause of acute abdominal pain, but can mimic a variety of acute surgical conditions. Computed tomography (CT) provides the diagnosis and avoids unnecessary procedures.

Background. Self-expanding metal stents (SEMS) are widely used to palliate patients with oesophageal cancer. Placement is usually done under endoscopic and fluoroscopic guidance. We have developed an exclusively endoscopic technique to deploy these stents. This article documents the technique and periprocedural experience.Patients and methods. All patients who had SEMS placement for oesophageal cancer at Grey’s Hospital, Pietermaritzburg, South Africa, over a 5-year period (2007 - 2011) were reviewed. Stenting was performed without radiological guidance using the technique documented in this article. At endoscopy, the oesophageal lesion was identified, dilated over a guidewire if necessary, and a partially covered stent was passed over the wire and positioned and deployed under direct vision. Data were captured from completed procedure forms and included demographics, tumour length, the presence of fistulas, stent size and immediate complications.Results. A total of 480 SEMS were inserted, involving 453 patients, of whom 43 required repeat stenting. There were 185 female patients (40.8%) and 268 male patients (59.2%). The mean age was 60 years (range 38 - 101). There were 432 black patients (95.4%), 15 white patients (3.3%) and 6 Indian patients (1.3%). The reasons for palliative stenting were distributed as follows: age >70 years n=95 patients, tumour >8 cm n=142, tracheo-oesophageal fistula (TOF) n=29, and unspecified n=170. One patient refused surgery, and one stent was placed for a post-oesophagectomy leak. Repeat stenting was for stent migration (n=15), tumour overgrowth (n=26) and a blocked stent and a stricture (n=1 each). Complications were recorded in six cases (1.3%): iatrogenic TOF (n=2), false tracts (n=3) and perforation (n=1). All six were nevertheless successfully stented. There was no periprocedural mortality.Conclusion. The endoscopic placement technique described is a viable and safe option with a low periprocedural complication rate. It is of particular use in situations of restricted access to fluoroscopic guidance.

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In this work we present an exact model of a spherically symmetric star undergoing dissipative collapse in the form of a radial heat flux. The interior of the star is matched smoothly to the generalised Vaidya line element representing a two-fluid atmosphere comprising null radiation and a string fluid. The influence of the string density on the thermal behaviour of the model is investigated by employing a causal heat transport equation of Maxwell-Cattaneo form., Comment: 12 pages, 2 figures

The mini-health technology assessment (HTA) tool is valuable in assessing the quality of decisions regarding health technology management in South African public hospitals. The tool demonstrates the needs for improved decision-making and for developing an appropriate, customised instrument to support decision makers regarding medical device management. Health technology in South Africa has changed rapidly over the past two decades. Current challenges include the introduction of rapidly developing diagnostic technologies such as point-of-care testing (POCT) devices and national health insurance. The mini- HTA tool can play an important role in effective and efficient management of health technology in this setting.