4. Electronic Theses and Dissertations (ETDs) - Faculties submissions
Permanent URI for this communityhttps://hdl.handle.net/10539/37773
Browse
1160 results
Search Results
Item Characterising skeletopathy in an animal model of type 2 diabetes(University of the Witwatersrand, Johannesburg, 2022-11) Dlamini, Gcwalisile Frances; Ndou, RobertType two diabetes (T2D) is a chronic, progressive heterogonous syndrome with a genetic and environmental origin. It is now recognized as an epidemic with a high morbidity and mortality rate. The endocrinology of type 2 diabetes (T2D) and its predisposing factors have been studied extensively, while diabetic skeletopathy has received negligible research. Previous studies report that fractures in T2D vary with specific sub regions in bones, therefore prompting our study to focus mainly on the femoral head and neck as well as the humerus head. Femoral neck fractures are the commonest, followed by the proximal femur, distal radius and proximal humerus. Susceptibility to fracture is a sequelae of poor bone remodeling. Poor bone remodeling is established at molecular and cellular levels. It depends on the activity of osteoblasts, osteocytes and osteoclasts, which are under the influence of TGF-β1, a pro-osteogenic cytokine, together with BMP3, an anti-osteogenic cytokine. T2D induced bone marrow adipocity and the accumulation of AGEs in cortical bone have also been implicated in increasing susceptibility to fracture. It is still unclear how T2D affects molecular and cellular elements that culminate in weaker bones observed in diabetic patients. In addition, it is debatable if T2D affects the skeleton at disease onset or later in the disease. Therefore, this study aimed to characterize T2D induced skeletopathy and related it to age, in the Zucker Diabetic Sprague Dawley (ZDSD) rat, using the femur and humerus. This study initially confirmed the diabetic state by monitoring animal weights, fasting blood glucose levels, and fasting oral glucose tolerance tests (OGTTs) every fortnight. Then triglyceride levels and quantified serum levels of osteoregulatory hormones such as insulin and osteocalcin were monitored. To assess oxidative stress, Malondialdehyde (MDA) serum levels were also determined by ELISA. Once diabetes was successfully induced, rats were grouped according to strain and age at termination. Termination age was at 20 weeks and 28 weeks . The Sprague Dawley (SD) rats were the controls, while the Zucker Diabetic Sprague Dawley rats (ZDSD) were the experimental groups. These were designated as SD20WK (n=8) and ZDSD20WK (n=7) respectively. Another batch was designated as SD28WK (n=8), and ZDSD (n=15) that were terminated at 28 weeks of age. The latter were further divided into moderate diabetes (ZDSD28WK-MOD) (n=9) and severe diabetes (ZDSD28WK-SVD) groups (n=6). Bilateral humeri and femora were harvested then fixed in 10% buffered formalin. Right proximal femora and humeri were scanned using a 3D-μCT scanner (Nikon XTH 225L) to analyse trabecular morphometric parameters, cortical bone area and medullary canal area. Biomechanical strength was analyzed by three point bending tests using a universal tensile tester. Left proximal femora and humeri were processed for histology. Some sections were stained with Haematoxylin and Eosin (H&E) to assess normal histologic morphology and adipocyte quantification. Remnant sections were immunolabelled using the anti-TRAP and anti-ALP antibodies for osteocyte and osteoblast quantification respectively, to assess osteolysis and osteogenesis. Immunolocalization of AGEs, TGF-β1 and BMP3 was also conducted to investigate their role in diabetic skeletopathy. We found that diabetes affected osteoblastogenesis as measured by ALP positive cells and bone marrow adipocytes. TRAP positive osteocytes numbers were increased in the presence of T2D, suggesting an increased osteolysis. There was reduced TGFB1 expression with increased BMP3 expression. The number of AGEs immuno-positive cells as well as its extracellular expression was increased. Our finding suggest that osteoblast and osteocyte numbers are regulated by TGFβ1 and BMP3 in both bones, under the influence of AGEs. Our findings from osteometry, 3-point bending tests and Micro CT support that diabetes weakens bone. The diabetic effect results in lighter, shorter hollow bones that perform poorly under loading, as well as exhibit unfavourable trabeculae microarchitecture. Our findings confirm that T2D causes increased fragility in the proximal femur and humerus as well the mid-diaphysis. These perturbations occur early and late in the disease, and they are also exacerbated by the presence of hyperglycemia. We conclude that the ZDSD rat can be used as a translational model for diabetic skeletopathy at cellular and molecular level, and it can be extrapolated to humans after consideration of other factors like, basal metabolism, age, sex and skeletal loading patterns. We recommend optimal control of blood glucose levels at all stages of the disease to reduce the incidence of fractures in diabetic patients.Item Bypassing the union: An Employer's Right to Negotiate Directly with Striking Employees(University of the Witwatersrand, Johannesburg, 2016-08) Nkosi, Thulani Gift; Mahomed, ShahedaSouth African labour law influenced by the Constitution and notions of equity and fairness has undergone a total change and will, without doubt, continue to change to meet the ever changing nature of employment it seeks to regulate. It is after all in the nature of all laws to change with the society they seek to regulate and our labour law is no exception. Recently, focus has shifted to the institution of collective bargaining and the questions posed are whether our labour laws as they currently stand are capable of adequately regulating the process of collective bargaining in such a way that the main objective of collective bargaining which is to bring about industrial peace is promoted and maintained at all times. These questions are posed on the back of the unprecedented spates of prolonged violent strikes that have resulted in the destruction of property and loss of life as well as unimaginable financial losses not only for the employers affected but also for the economy as a whole. These unprecedented prolonged violent strikes have caused employers to engage in bargaining conduct that could erode the participation of trade unions from the collective bargaining process which bargaining conduct takes the form of employers bypassing trade unions and negotiating with striking employees directly. But do employers have a right to bypass trade unions in this way? This paper investigates this question against the background of the case of Amcu v Lonmin where the Labour Court on application by a trade union had to decide whether to grant an urgent interdict restraining employers from negotiating directly with striking employees. The employers considering themselves to be acting within their rights opposed the application. The Labour Court unfortunately dismissed the application on technical grounds relating to the lack of urgency without considering or deciding this question. This paper accordingly picks up the debate; considers the historical evolution of collective bargaining in our labour law including the voluntarist argument that is said to be embodied by the Labour Relations Act (LRA), and concludes that when all things considered employers in fact do not have a right to bypass trade unions. If employers had this right certain provisions of the LRA that guarantee trade union participation would be rendered nugatory and the whole collective bargaining process would become unworkable. The LRA envisions that once parties have voluntarily embarked on collective bargaining they bargain in good faith and do not bypass each other.Item Support programme for healthcare professionals involved in adverse events in public hospitals in Gauteng(University of the Witwatersrand, Johannesburg, 2022-12) Nkosi, Elizabeth Malefu; Armstrong, Sue; Nkosi-Mafutha, NokuthulaBackground: Adverse events in the healthcare services result not only in administrative and financial costs to the healthcare institution, but also in personal costs to the patients and their families, who are often angry, disappointed, and sad. In the current litigious healthcare climate, relatives, supported by legal advisors, often seek redress as a way of managing their distress. Thus, patients are not the only victims of adverse events. The healthcare professionals that are directly involved often shoulder the blame, sometimes fairly, and sometimes unfairly, while they too need psychological support. A culture of blame in institutions can lead to healthcare professionals involved in an adverse event being marginalised, feeling personally responsible for the event and that they have failed the patient, and they are left to suffer in silence. While anecdotal evidence exists that such stress may lead to negative coping mechanisms, the researcher has not identified any research study conducted in public hospitals in Gauteng, South Africa that identifies and describes the influence that the involvement in an adverse event has on healthcare professionals. Such evidence is required to develop a support programme that could assist healthcare professionals who have been directly involved in adverse events, to minimise the concomitant stress, and to enable these professionals to continue to provide quality care after such an event. Aim: The purpose of this study was to develop, describe, and evaluate the implementation of a support programme for healthcare professionals involved in adverse events in public hospitals. Methodology: A sequential, multimethod research design was used. The study was conducted in five phases. Phase 1 consisted of a scoping review of the international literature that focused on the experiences of the nurses and doctors. The question asked in the scoping review was: What is known from existing literature about the support programmes for healthcare professionals involved in adverse events in clinical settings, and are they effective? Phase 2 involved storytelling that explored the impact of adverse events on involved healthcare professionals. Smith and Liehr’s (2005) methodology was used, that is, healthcare professionals who were directly involved in or affected by one or more adverse events in the public hospitals in Gauteng narrated their experiences. Phase 3 used semi-structured interviews with the managers to explore how best to support health professionals involved in adverse events. Phase 4 involved developing a support programme according to the Wits Trauma Model developed by Eagle, Friedman and Shumkler, from the Psychology Department of the University of the Witwatersrand, in 1993 (Eagle, 2000). Phase 5 focused on confirming and validating the programme to support healthcare professionals involved in adverse events in public hospitals. This phase was subdivided into two sections: Phase 5.1 comprised the Delphi group; and Phase 5.2 comprised the Focus group. In the first round involving the Delphi group, technical data was collected from the experts who validated the programme by means of the survey that was distributed on Research Electronic Data Capture. Concerns arising out of the first round with the Delphi group and that required attention were addressed during the Focus group discussion. Results: Hospitals were not aware of the magnitude of second victimhood and hence the delay in reviewing the structures in place to provide support to those involved. Just (fair) culture principles were not adhered to as there were no guidelines for their implementation, hence the second victims were left traumatised and in isolation following their involvement in adverse events, and they experienced blaming by management instead of being provided with much needed support. Limitations: The limitations to the study include the small sample size during the data collection phases, due to the Coronavirus disease of 2019 pandemic. Due to the restrictions that were implemented it was not possible to contact all the staff as they had been relocated to other healthcare facilities, were absent, or had resigned. Those who were snowballed were no longer at the facilities where they were originally identified, and therefore the researcher was unable to capture their experiences. Objectivity was not maintained as the documents for the Delphi group were hand-delivered, participants were able to identify the researcher, and hence the social desirability concern. The face-to-face encounters made adherence to anonymity impossible. The model components were not practical in terms of the developed programme. Round two of the Delphi group could not be scheduled, thus challenging the study model. Conclusion: The impact of adverse events on healthcare professionals remains an underestimated health concern. Experiences are magnified by unsupportive work environments, and are evident in increased hostility, blaming, fear of punishment, and reputational harm. The second victims require support to enable them to recover and learn from their involvement. The programme was developed, which included the summarised structure and the detailed process for implementation by hospital management on how to manage the adverse events in public hospitals in Gauteng.Item The perceptions of social workers on the implementation of the Occupation Specific Dispensation policy (OSD) within the Department of Social Development in the Johannesburg Region(University of the Witwatersrand, Johannesburg, 2020) Mathebula, Sipho Sol; Masinga, PoppyThe Occupation Specific Dispensation (0SD) policy was introduced in the public service for social workers in 2009 as a strategy to recruit and retain social workers with the introduction of new salary scales, career pathing, pay and grade progression and recognition of appropriate experience. The perceptions of social workers on the implementation of the OSD policy have not been established and this lack of knowledge leaves a gap in understanding the perceived impact this policy has had on social workers. The aim of the study was to explore the perceptions of social workers on the implementation of the Occupation Specific Dispensation policy within the Department of Social Development in the Johannesburg Region. Since implementation of the policy, there has been research studies conducted on the outcomes of the OSD policy within the public health sector yet no studies have been conduct that focus on the challenges encountered by social workers in the implementation of the policy. The study utilised the qualitative research approach which was exploratory and descriptive in nature. The collective case study design was adopted. A sample of ten social workers and three key informants were selected using purposive sampling. Data was collected using semi-structured interviews and analysed using thematic content analysis. The key finding was that the OSD policy was not effective in recruitment since it is rigid and inflexible. Another concern raised was the long period it took to move from one occupational level to the next resulting in a demotivated and demoralised workforce. The study also found that there was management bias in the implementation of the performance management and development system. The study contributes to our understanding of the perceptions about the unintended consequences of the OSD policy and how these are perceived to have impacted negatively on the recruitment and retention of social workers.Item Could Not Sing in the Dead Heat: Liner Notes Under the Sun(University of the Witwatersrand, Johannesburg, 2022) Ramphalile, Molemo Karabo; Schuhmann, AntjeOn the one hand we place blackness as a historical if inconsistent category inextricable with morbidity, disfavour, depravity, mystery, wretchedness, penumbra, opacity or absence of light, and the abyssal – in both secular and religious metaphysical symbolism. On the other hand we place space as a historical and physical category denoting area, range, clearance, scope, volume, expanse, lacunae, aperture, margin, and in its instance as verb – opening, arranging, ordering, placing, separating, and locating; which in cosmography, geography and cartography finds its varied imaginative and applied interpretation. We coalesce what is in both hands in order to envisage how blackness persistently becomes and comes to be the extractable property of sub-Saharan Africans. Through various ontological-cosmographic- geographic designations such as Torrid Zone, ‘land of the blacks’ or even terra nullius, we encounter visualisations of a territory and expanse that is always either completely devoid of people or inadequately peopled, that is, the territory whence blackness as inextricably embodied (or fleshened) exists and is cultivated. Blackness: not only does it determine our modes of being, or non-being, in this world, but for us in this study, it is also an experiential, experimental and analytical lens permitting the suggestion and scribing of historical narratives and discourses that centre the inveterate decentring of blacks. In the tradition of liner notes, this study is written in a performative relation to the subject or object at hand; there under the sun, in the dead heat.Item Design and development of a bioactive-loaded polymer-engineered neural device for potential application in reducing neurological deficits after spinal cord injuries and neuro-regeneration(University of the Witwatersrand, Johannesburg, 2017) Kumar, Pradeep; Choonara, Yahya Essop; Modi, Girish; Naidoo, Dinesh; Pillay, VinessTraumatic Spinal Cord Injuries (SCI), due to their devastating nature, present several interventional challenges (extensive inflammation, axonal tethering, scar formation, neuronal degeneration and functional loss) that need to be addressed before even a slight neuronal recovery can be achieved. Recent post-TSCI investigational approaches include support strategies capable of providing scaffold architecture to allow axonal growth and conformal repair. This research provided detailed insight towards the development and fabrication of six specialized Polymer-Engineered Neural Devices (PENDs): 1) poly(lactic-co-glycolic acid)-gliadin (PLGA-GLDN) nanofibrous mats, 2) polyacrylamidated chitosan (PAAm-g-HT) scaffold, 3) functionalized chitosan methoxypolyethylene glycol (CHT-mPEG) cryosponges, 4) polyacrylonitrile-elastin-collagen (PANi-EC) neurosponge, 5) methylcellulose-alginate-polyethylene glycol (MAP) thermogel, and 6) chitosan-luronic F127-β glycerophosphate (CHT-PF127-βGP) composite thermogel for potential restriction, repair, regeneration, restoration and reorganization post-SCI. The latest trends in biomaterials-based SCI intervention were reviewed, discussed and analyzed in detail throughout the thesis. The research also involved an in silico analytico mathematical interpretation of multi(biomed)material assemblies wherein quantification of energy surfaces and molecular attributes via atomistic, dynamic, and docking simulations was carried out. The in silico experimentation additionally confirmed the potential of curcumin as a bioactive of choice for SCI intervention. Curcumin and dexamethasone were incorporated into the compact scaffolds and the bioactive release was determined over a period extending up to 60 days. The PLGA-GLDN nanofibrous mats demonstrated the formation of a compatible blend among the component polymers at equal weight ratios (PG55) as confirmed by quantitative physicochemical characterizations. Image processing analysis (DiameterJ plug-in of ImageJ) was performed on the SEM images of nanofibers to quantify the size, porosity, and orientation of the samples. Nanofibers within the size range of 10nm and 250nm were obtained in case of compatible blend and the nano stack was used for in vivo implantation post-SCI. Polyacrylamidated chitosan (PAAm-g-CHT) was synthesized via a unique persulfate-mediated polymer slicing and complexation as determined by static lattice atomistic simulations. The graft copolymer so obtained was fabricated into an anisotropic neurodurable scaffold. The CHT/mPEG cryosponges showed unique morphological features such as fringe thread-like structures (CHT alone); hemispherical, pebble-like structures (CHT-mPEG); curved quartz crystal-like or crystal-flower-like structures (CHT-mPEG-CHO); and grouped, congealed, steep-sided canyon-like structures (CHT-mPEG COOH). A novel image processing protocol involving DiameterJ and ND plugins of ImageJ software was employed for analyses of the SEM micrographs in terms of % porosity, pore wall thickness and % xiiehaviorxii of the porous scaffolds. The PANi-EC interpenetrating polymer network neurosponges were synthesized employing free radical polymerization under acidic conditions wherein first-in-the-world spinomimetic scaffolds were obtained. The unique feature of the PANi-EC neurosponge was the formation of a fibrous neurotunnel architecture mimicking the native spinal cord. The physicochemical characterization revealed that the secondary structure of the peptide molecules (elastin and collagen) rearranged in the presence of PANi to their native extracellular matrix (ECM) form confirming the self-assembling nature of the polymer-peptide architecture. Furthermore, the PANi-EC neurosponge provided a perfect balance of matrix resilience and matrix hardness similar to the native collagen-elastin complex in vivo. Two very interesting tri-component thermogels were reported here viz. a simple blend thermogel comprising methylcellulose, sodium alginate and poly(ethylene glycol) and a complex thermogel incorporating chitosan, Pluronic F127 and β-glycerophosphate. Both the thermogels solidified at physiological temperature confirming their applicability in vivo. The outstanding feature of MAP thermogels was the formation of hydrogen bonded O-H…C=O which only formed in the tripolymeric blend while the bipolymeric blends showing no such interaction. We proposed that the MAP thermogel self-assembled into a repeating network structure represented by “PEG400-ALG-hydrophillicMChydrophobic}-{hydrophobicMC-hydrophilic}-ALG-PEG400” and the physical “compression” might have led to the formation of hydrogen bonded O-H…C=O among MC/alginate or PEG/alginate in the presence of PEG or MC, respectively. In case of the complex CHT/PF127/βGP thermogel, a unique triphasic gel-sol-gel transition xiiehavior was observed with the thermogel forming a gel-phase at lower temperatures (T<20°C), a sol-phase at intermediate temperatures (20°C35°C). The MTT proliferation studies indicated that all polymer engineered neural devices (PANi-alone matrix) were capable of efficiently supporting the growth of PC12 cells compared to the control over a period of 72 hours. The fundamental objective of this thesis was to test the applicability and capability of various biomaterial composites towards the repair and regeneration of neuronal tissue after traumatic spinal cord injury. Although drug-loaded scaffolds were also developed, only drug-free scaffolds (PLGA-Gliadin 5:5 electrospun nanofibers; PANi-Elastin-Collagen neurosponge; and Chitosan/Pluronic F127/β-glycerophosphate thermogel) were tested in vivo for the proof-of-concept. The 21-point scale BBB locomotor rating analysis demonstrated that PEND I (14), PEND II (19) and PEND III (18) provided significant motor recovery as compared to the lesion-control (5) group 28 days post-SCI and –implantation. The immunohistochemistry confirmed that reparative changes were accompanied by marked upregulation of iNOS, a notable influx of ED1-positive chronic inflammatory cells, the appearance of multinucleate cells characteristic of presumptive regenerative neuroblasts and near-complete loss of GFAP and NF-200 protein/structural integrity. Almost complete functional and neurostructural recovery was observed with post-SCI implantation of PEND II and III. In conclusion, the composite scaffolds tested in this research demonstrated immense potential in improving the neurological, neurochemical, and behavioral outcome after implantation post-SCI.Item Co-gasification of Coal and Solid Waste to Hydrogen Enriched-Syngas in a Fixed Bed Gasifier(University of the Witwatersrand, Johannesburg, 2020-10) Ozonoh, Maxwell; Daramola, Michael O.; Oboirien, Bilainu O.The economic growth of every nation around the globe is centred on energy. Energy can be harnessed from different sources using different conversion systems, but such systems should be sustainable. Liquid fuels such as petroleum and solid fuels (e.g. coal & biomass) are largely used for energy production. Energy recovery from these fuels is usually carried out using thermal chemical processes such as combustion, pyrolysis, and gasification systems. Out of the three technologies, gasification is considered the most attractive based on its efficiency and other qualities. In the gasification process, syngas is produced. It is necessary to produce syngas of high quality such as hydrogen-enriched syngas. Hydrogen-enriched syngas can be used in fuel cells, gas turbines and engines for electricity production. This type of gas burns with little gaseous emissions to the atmosphere, but its production is dependent on the type of fuel and process conditions, and energy conversion system employed. In South Africa, around 95 % of electric power production comes from coal, and the current reserve is projected to last not more than a century [8]. Secondly, the coal is fast depleting and generates a lot of gaseous emissions (e.g. CO2, NOX & SOX) that pose a huge threat to the environment. The emission of the aforementioned gases is a very serious issue in South Africa. Presently, some Carbon Capture and Storage (CCS) projects are on-going in the country, although the CCS is not the fuse of this study. The gasification of biomass waste and coal could assist in gaseous emission reduction. Similarly, large amounts of agricultural wastes (e.g. sugarcane bagasse, corn cob & pine saw dust) and other solid waste such as tyre are in abundance in SA. It is detailed in chapter 2. Majority of the wastes are disposed indiscriminately, hence resulting in environmental pollution. Importantly, the solitary gasification of biomass is very expensive considering the prices of biomass. Besides that, biomass produces large amount of tar hence, resulting in operational difficulties in the gasifier and end user facilities. In this study, co-gasification of coal and solid wastes is considered as a crucial alternative to addressing the aforementioned problems. Particularly, the feedstocks used for this study were coal, biomass (corn cob (CC), pine sawdust (PSD), sugarcane bagasse (SCB)) and waste tyre (WT) and were pre-treated by drying, milling, sieving, and torrefaction (coal was not torrefied). The fuel samples were blended with coal at different ratios as detailed in the thesis and used for the study. For the torrefaction process, the most viable torrefaction process conditions and feedstock were determined, while the torrefaction process model for the feedstocks were developed, using Response Surface Methodology (RSM) and Artificial Neural Network (ANN), respectively. The Performance efficiency of gasification systems was evaluated using experimental data obtained from a few gasifiers (e.g. entrained, fluidised, and fixed bed) operated at varied experimental conditions using blends of feedstocks (e.g. biomass, coal, waste tyre etc.). A backpropagation Levenberg Marquardt (L-M) and Bayesian Regularisation (BR) algorithms of ANN model with Multiple Input- Multiple Output (MIMO) and Multiple Input-Single Output (MISO) layer networks were considered. The results of the MIMO and MISO layer networks obtained from the L-M algorithm were better than that of BR algorithm which is in affirmation with some of the results found in the literature. For model result improvement, Input Variables Representation Technique-by-Visual Inspection Method (IVRT-VIM) and Output Variables Representation Technique-by-Visual Inspection Method (OVRT-VIM) were developed from the study. Estimation of the gaseous emissions and profits from biomass, tyre, and coal fired co-gasification CHP Plant using Artificial Neural Network (ANN) was carried out for 20-year investment period using South Africa (SA) and Nigeria as cases studies via Artificial Neural Network (ANN). Higher profits were obtained from South African feedstocks than that of Nigerian feedstocks due to cheaper price of SA coal WFO and WOFC, but the gaseous emissions (CO, NOX, & SO2) from the Nigerian fuels were lower than that of SA because of differences in compositions of the fuels. The potentials of biomass torrefaction in terms of profitability in a co-gasification CHP plant for a 20-year-investment period was carried out using blends of Coal + SCB, Coal + CC, and Coal + PSD with coal-to-biomass ratio of 50:50, 71:29, and 80:20, respectively. The two financial cases mentioned earlier were considered. Four investment terms including: (A) 1st–5th, (B) 5th– 10th, (C) 10th– 15th & (D) 15th– 20th and two operational cost models; with feedstock costing (WFC) and without feedstock costing (WOFC) were employed. An estimated profit of between USD5.9 million - USD6.5 million and USD7.8 - USD7.9 million was earned at the end of investment plan using WFC and WOFC, respectively. The Internal Rate of Return (IRR) was 5 ± 1 %/yr. and 7 ± 4 %/yr. based on South African electricity price of 0.14 $/c kWh, respectively. The parametric effect of process variables during torrefaction of coal/biomass/waste tyre blends using ANN and RSM models were studied. The variables considered were Higher Heating Value (HHV), Enhancement Factor (EF), and Sold Yield (SY). The most effective operating process conditions (in terms of blending ratio, temperature and torrefaction time: input variables) is of the order: 50:50 at 300 OC and 45 min > 50:50 at 250 OC and 30 min >50:50 at 200 OC and 45 min. Similarly, the most viable fuel follows the order of Coal + Torrefied PSD > Coal + Torrefied SCB > Coal + Torrefied CC and > Coal + Torrefied WT. Coal + Torrefied PSD has HHV of 28.27 % and an EF of 1.41. This corresponded to around 10 % increase in the HHV of the torrefied fuel when compared to the raw fuel and about 25.23% higher than the EF of Coal + Torrefied WT of 1.03. Based on the result of the EF of Coal +Torrefied waste tyre, upgrading of the fuel quality via torrefaction is not recommended. Furthermore, a comprehensive study on tar treatment techniques was carried out using tars produced from biomass and blends of biomass and coal employing biochar based and Ni-biochar based catalysts. Box Behnken Design of Experiment (DoE) method was used. A full quadratic regression model was used to develop a mathematical model for tar treatment based on the feedstocks studied. The Pine Sawdust-Biochar Catalyst (PSD-BC) and Nickel Pine Sawdust-Biochar Catalyst (Ni-PSD-BC) were the most effective in terms of tar treatment and with an average percentage amount of tar conversion of 89.76 and 96.73%, respectively. Ni-PSD-BC was more efficient for tar cracking than PSD-BC, but PSD-BC (waste base) may be more attractive if sustainability and cost effectiveness of precursors are considered. Co-gasification of coal and pine sawdust (PSD) to hydrogen enriched syngas in a fixed bed gasifier was carried out with catalyst (WCAT) at 900 OC and without catalyst (WOCAT), at 700, 800, and 900 OC, respectively. Coal-to-PSD ratio of 1:1 was used, while Nickel-pine sawdust-biochar (Ni-PSD-BC) and pine sawdust-biochar (PSD-BC) were employed as catalysts. The gases produced at 700, 800 & 900 OC using WOCAT cannot be used in fuel cells and gas turbines due to poor quality, while others produced at 900 OC WCAT, can be used in internal combustion engines and gas turbines, but unfortunately, have lower quality to be employed in fuel cells for electricity production. However, the study provides a method of beneficiation of the high ash content South African coal for energy production. The outcome of this study is also instrumental to energy security, efficiency and sustainability as well as waste management in South Africa, Nigeria and other parts of the globe. An assessment of the economic, energy and environmental viability of a 5 MW co- gasification power plant was carried out, using blends of coal and biomass, and two financial cases were considered namely: with feedstock costing (WFC) and without feedstock costing (WOFC). Feedstock profitability in the plant for energy production was evaluated. Equipment consisting was not considered. The power plant used 20,473,451.41 kg, 20,986,049.96 kg, 18,251,806.49 kg, and 15,276,277.85 kg of Coal + SCB, Coal + CC, Coal + PSD, and Coal + WT to produce the 5 MW and 5.56 MW electric and thermal power, annually. Coal + Torrefied PSD was the most profitable of the fuels studied. The use of Coal-to-PSD ratio of 4:1 for the power generation as against Coal-to-PSD blend ratio of 1:1 resulted to an annual loss of about ZAR6, 461,301.77 ($90,458,224.70) and ZAR123,782.47 ($1,732954.58) WFC and WOFC, respectively.Item Voiding cystourethrography in the renal pre-transplantation workup: an essential investigation?(University of the Witwatersrand, Johannesburg, 2022-10) Sofianos, Zelia; Rajkumar, Leisha; Lucas, SusanINTRODUCTION: Due to resource constraints in the South African public healthcare sector, patients with End-Stage Renal Disease (ESRD) are eligible for renal replacement therapy only if they are also found to be eligible for renal transplant. AIM: The aim of this study is to document Voiding Cystourethrogram (VCUG) findings in potential renal transplant candidates to assess the contribution of the VCUG as a standard investigation in the renal transplant workup. METHODS: Of the patients who underwent VCUG in Klerksdorp/Tshepong Hospital Complex (North West province, South Africa) from 1 January 2019 to 31 March 2020, 85 patients were included in the study and their VCUG findings retrospectively analysed. RESULTS: The mean age was 40.0 years (range 21-62 years), with males constituting 57.7% of patients and females 42.3%. Lower urinary tract abnormalities were identified in 24.7% of patients, some of whom had more than one abnormality. Of the total abnormalities, VUR (vesicoureteral reflux) accounted for 15.3%, bladder diverticula for 5.9%, urethral strictures for 3.5% and a significant post-void residual volume for 4.7%. No comorbidities were found to have a statistically significant association with the presence of VCUG abnormalities. CONCLUSIONS: To ensure that patients with End-Stage Renal Disease are adequately prepared for renal dialysis and potential renal transplant, and that their comorbidities and lower urinary tract are optimised should abnormalities be identified on VCUG, the VCUG remains an essential investigation in the renal transplant workup.Item Emergency Department Turnover Intention: Are Job Satisfaction and Burnout Really the Main Culprits?(University of the Witwatersrand, Johannesburg, 2022-11) Jonker, Yvonne Denise; Motara, Feroza; Moolla, MuhammedBackground: Patient presentations to emergency departments (ED) keep increasing. High staff turnover is detrimental to the healthcare worker (HCW), the organisation and the patient. While high levels of burnout (BO) and low levels of job satisfaction (JS) lead to a higher intention to leave (ItL), there are other factors affecting the ItL that need to be evaluated. Objective: To determine the levels of BO, JS and ItL, including when, where and why HCWs want to leave in order to find ways to reduce staff turnover. Methods: This was a prospective observational cross-sectional study conducted in two tertiary-level EDs in Johannesburg, South Africa namely Chris Hani Baragwanath Academic Hospital (CHBAH) and Charlotte Maxeke Johannesburg Academic Hospital (CMJAH). Doctors and nurses were invited to complete self-administered questionnaires between 24 November 2020 and 24 March 2021. After analysis the results for doctors and nurses and the two units were compared in order to bring understanding to the different facets affecting staff turnover. Results: A total of 78 respondents (66% of doctors and 58% of nurses) completed questionnaires and were included for analysis. According to the Copenhagen Burnout Inventory 79% of CHBAH doctors, 62% of CHBAH nurses, 79% of CMJAH doctors and 84% of CMJAH nurses suffered from severe personal burnout, while 68% of CHBAH doctors, 62% of CHBAH nurses, 95% of CMJAH doctors and 68% of CMJAH nurses suffered from severe work-related BO and 42% for CHBAH doctors, 24% of CHBAH nurses, 47% of CMJAH doctors and 32% of CMJAH nurses had severe patient-related burnout. Doctors had significantly higher patient-related burnout (p=0.012). JS was average for all staff but nurses were significantly less satisfied (p=0.003). While 42% of staff intended to leave within a year, of which half wanted to leave as soon as possible, a total of 73 % wanted to leave within 5 years. CMJAH staff had higher levels of BO, lower levels of JS and higher levels of ItL. Higher levels of BO and lower levels of JS increased the ItL. The main reasons for leaving were career-related. Conclusion: Burnout levels were higher than similar populations before and during the Covid-19 pandemic, while job satisfaction levels were average. Although burnout and job satisfaction affected intention to leave, the main reasons for wanting to leave were career-related indicating that even when work conditions and burnout could be addressed successfully, the turnover of staff in tertiary level EDs may remain high.Item Analysis of Orthopaedic Injuries in Polytrauma Patients at Charlotte Maxeke Johannesburg Academic Hospital(University of the Witwatersrand, Johannesburg, 2022) Laney, Wezley; Naicker, Dharshen; Milner, BrendaBackground: Traumatic injuries represent a significant burden globally, accounting for ten percent of the global burden of disease. In South Africa we commonly see patients who have sustained major trauma, often with multiple injuries. This significant burden of trauma necessitates the demand for rapid diagnostic assessment of injuries for appropriate therapeutic intervention. A whole body computed tomography (CT pan scan) allows for a rapid multisystem injury diagnosis of trauma patients. There is a scarcity of literature evaluating the extent of orthopaedic injuries in polytrauma patients. Study Aim: The aim of the study was to evaluate the local epidemiology of orthopaedic injuries in polytrauma patients who have undergone a CT pan scan. Methods: A retrospective, observational analysis, based at Charlotte Maxeke Johannesburg Academic Hospital, was done of polytrauma patients who underwent a CT pan scan, during a 2-year period from 01/01/2018 – 31/12/2019. A database was compiled by accessing the picture archiving and communication system for CT reports. The qualitative data was reported using frequencies and percentages. Categorical variables were analysed using the Chi-squared test (or Fisher’s exact test). Results: Over the two-year study period a total of 296 polytrauma patients had a reported CT pan scan performed. Of these, 85% were male and 15% were female with a median age of 33 years. The most common mechanism of injury was motor vehicle accidents (33.1%). The prevalence of orthopaedic injuries in polytrauma patients was 53.3%. A total of 1012 injuries were found. One hundred and ninety-six (196) spinal fractures were detected; a total of 137 pelvic/sacral fractures, 101 long bone fractures with 75% lower limbs and 25% were upper limb fractures. The most common non-orthopaedic injury sustained was a chest injury. The most common combination of orthopaedic and non-orthopaedic injuries identified in the study was a chest injury with an associated pelvic/sacral fracture secondary to a PVA. Interpersonal and intentional injuries were significantly associated with a higher risk of thoracic spine fractures (RR 1.8, CI 1.1-2.9). Road traffic accidents were significantly associated with a higher risk of scapular/clavicular fractures (RR 2.0, CI 1.2-3.5) and a higher risk of tibial/fibula fractures (RR 3.5, CI 1.2-10.3) Conclusion: The majority of polytrauma patients seen at CMJAH were young males, who sustained injuries during road traffic accidents. Fractures accounted for 94% of all orthopaedic injuries. The most common orthopaedic injury detected in our cohort, overall, was a spinal fracture, most commonly involving the cervical spine. A patient involved in a road traffic accident is 3.5 times more likely to sustain a tibia/fibular fracture as opposed to any other fracture. The most common non-orthopaedic injury sustained was a chest injury. Importantly, 1 in 4 of these patients sustained an associated cervical spine injury and 1 in 3 a pelvic injury, similarly with head injuries. The most common combination of injuries is a chest injury with an associated pelvic/sacral fracture secondary to a pedestrian vehicle accident. The findings highlight the significant burden of orthopaedic injuries in polytrauma patients. In addition, the findings of this study, highlight injury patterns that should be anticipated in polytrauma patients.