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Item A study of the support effect of carbon dots-derived graphene-like sheets on the autoreduction of cobalt nanoparticles for Fischer–Tropsch synthesis(2022) Mokoloko, Lerato LydiaThe aim of this study was to synthesize and characterize carbon dots (CDs) and to use them as a support material for cobalt (Co) based Fischer-Tropsch synthesis (FTS) reactions. The CDs were chosen for this study due to their small size (< 10 nm), easy surface functionalization and synthesis. The small size of the CDs was required for the study of inverse catalyst support effects. An inverse supported catalyst (in this case, the Co/CDs catalyst) refers to the dispersion of a support material that has a small size (d < 5 nm) onto the surface of a metal catalyst with a similar small size (d > 8 nm). The synthesis of this proposed catalyst was successful. FTS studies on the Co ‘supported’ CDs were attempted. Extremely poor FT activity was observed. Post analysis of the catalyst revealed that the CDs did not retain their quasi-spherical and small particle size morphology under the FTS reaction conditions (temperature 220 °C, 10 bar P; H2:CO ratio = 2:1). Instead, upon exposure to a heat treatment, the CDs were transformed into layered structures with a unique resemblance to graphene-based nanosheets (GNSs). This transformation impacted on the use of these catalysts in the FTS reaction. However, this result indicated an unusual transformation of the CDs into another carbon shape. In light of the fascinating transformation phenomenon, annealing studies were then conducted to investigate the effect of annealing temperatures on the CDs structural changes. The CDs (average d= ~ 2.5 nm) used in this study were obtained from the microwave-assisted carbonization of L-ascorbic acid and subjected to a heat treatment (i.e. annealing) at temperatures between 200 and 700 ℃ in a horizontal CVD apparatus under an inert nitrogen gas. It was observed that annealing transformed the CDs from 0-D qausi-spherical nanoparticles to 3- D multi-layered carbons (at 300-600 ℃) and finally 2-D layered materials (at 700 ℃). Furthermore, annealing at 700 ℃ yielded a 2-D single-layered material with comparable properties to traditionally reduced graphene oxide (rGO). A wide range of characterization techniques were used to gain an insight into the physicochemical properties of these novel CDs-derived allotropes as well as to rationalize their mechanism of formation. After evaluating the properties of these materials, it was clear that the surface oxygen functional groups, observed from XPS, 13C NMR and other studies, were responsible for the CDs to rGO transformation. It was proposed that the CDs are assembled to form rGO (and other CDs-rGO derivatives) by either the Ostwald ripening (in which the carbons agglomerated via a gas phase) or a solid phase reaction (involving reaction of CD edges). To further investigate the effect of annealing on the evolution of CDs to layered carbon structures, N-doped CDs (or NCDs) were also studied. The method used to make the pristine CDs was modified by incorporating urea as a nitrogen source to make the NCDs. Annealing the NCDs at temperatures between 200 and 700 ℃ also transformed the quasi-spherical NCDs (average d = ~ 4.1 nm) to multi-layered carbon sheets at temperature as low as 200 ℃. The CD transformation was also associated with the loss of surface functional groups, with % O and N contents of ca. 17 and 16 % (pristine NCDs) being reduced to ca. 8 and 7 % for NCDs annealed at 700 ℃. A similar mechanism for the formation of these N-doped layered carbon structures by annealing was also proposed here. For these samples, it was also observed that the N-bonds, especially the sp3 type nitrogen bonds found on the edges of the NCDs, also took part in the coalescence of the NCDs to give the layered materials. XPS data suggested that in the process, these sp3 type nitrogen bonds were transformed into sp2 pyrrolic-N, pyridinic-N and GraphiticN groups. The annealed CDs products were used to support Co (called Co3O4/T250, Co3O4/T400 and Co3O4/T700 where T is the temperature at which the CDs were annealed) for use in FT studies. Studies were conducted to evaluate the effect Co hydrogen reduction temperatures verses autoreduction temperature, catalyst thermal stability and performance in the FTS reaction at 220 °C (10 bar P; H2:CO ratio = 2:1). Upon investigation of the reduction behaviour of the Co/CDs derivative catalysts using in situ PXRD, it was found that these materials can successfully facilitate autoreduction of Co3O4 to Co face-centered-cubic (fcc) at temperatures > 400 ℃ by a reduction pathway similar to that observed using conventional H2 reduction conditions. As expected, the reduction under H2 took place at a lower activation temperature (> 250 ℃) than the autoreduction process. It was also noted that these novel carbon support derived from CDs gave reduced FTS performance compared to the unsupported Co, especially towards C5+ yields (< 30 % for all Co supported catalysts). These novel CDs-derived allotropes were found to have limited use as supports in Co-based FTS, due to Co agglomeration. These NCDs-derived allotropes (annealed at 200 ℃, 400 ℃ and 700 ℃) were incorporated as active layers in the fabrication of chemoresistive sensing device detection of volatile organic compounds (VOCs). These layered showed enhanced chemical vapour sensing properties, especially for methanol and ethanol detection at room temperature. Therefore, although there are great limitations for applications of these CDs-derived layered allotropes in FTS reaction, these materials show a much better potential for applications in facile and cost effective VOC sensors. Further studies on this will be conducted.Item Analysing the player's involvement in video game character animation(University of the Witwatersrand, Johannesburg, 2021) Ponde, Rugare; Whitcher, RayThis dissertation investigates the impact of animation on player interest in an existing video game character. There is high demand and expectation regarding character animation quality, yet understanding and achieving this standard is complex and challenging. The quality of a character’s animation is often derived from its direct appeal to the audience and how its representation informs their impression. However, there is a gap in the literature where there is little on how style representation plays a role in character perception and identification in video games. A practice-led approach was used to understand the relationship between player involvement and the player-character's appeal. The process involved the creation of an animation reel to demonstrate how a popular video game character's acceptance can change based on a player's perception of style in the character's animation. I used Link from the video game Super Smash Brothers Ultimate (Nintendo, 2018). The reel was presented to adults between 18 and 35 to review the animations. Using the process of creative exegesis, the theories and concepts about character appeal, animation design, and player involvement were combined to analyse and critique the contributing factors that inform the perception of the creative work. The results from this study indicate that a change in movement style impacted the perception of Link and the participant's demonstrated interest to play him. This study confirms that style representations are an important design consideration to improve a character’s appeal. This topic may benefit the art and technique of character design and how to improve on it.Item Anxiety as a Mediator of the Associations Between Stressful Life Events and Social Media Use Intensity in Young Adults(University of the Witwatersrand, Johannesburg, 2022-05) Ramoroka, Morongwa Rebaabetswe Elina; Price, EstherIntroduction: This study quantitatively explored the associations between SLEs, anxiety, and social media use intensity. The study explores whether anxiety mediates the relationship between SLEs and social media use intensity across all four domains. This study further aims to explore whether social media use intensity, operationalized as an avoidance coping strategy, is possibly due to poor emotional regulation and distress tolerance skills. The first-time undergraduate student population are often inadequately prepared for the transition to university during a critical period of their development. As a result, they may drift towards health compromising behaviours such as intense social media use. The findings will set a precedent for the development of preventative programs and/or interventions in order to assist young adults with emotional regulation. Methods: This was a cross-sectional design that was analysed quantitatively. The participants were invited to participate in online questionnaires which assessed stressful life events, anxiety, and social media use intensity. While a total sample of 402 students completed parts of the online survey questionnaires, a final sample of 360 participants was used in the study as their data sets were complete for all the variables. The Social Readjustment Rating Scale, Beck's Anxiety Inventory, and the Facebook Intensity Scale were the measures used. Results: Positive associations were found between SLEs, anxiety and social media use intensity. Anxiety mediated the relationship between SLEs and social media use intensity across all four domains. This reflected that social media use intensity is a form of avoidance coping mechanism that emerges due to poor emotional regulation and distress tolerance skills. Conclusions: The present study highlights the challenges experienced and how to set a precedent for the development of preventative programs and interventions. Keywords: stressful life events, anxiety, avoidance coping, social media use intensityItem Assessing financial literacy amongst anaesthetists in an academic department(2024) Mohamed, Ayesha NoorBackground: Financial literacy is an important skill that is used to navigate the complex financial landscape. According to studies done in South Africa, wealth, income, racial classification, age, geographical location and level of education affect financial literacy levels. Higher financial literacy is associated with greater wellness and less financial concerns. Studies done in other countries show that doctors have low financial literacy. The financial literacy of anaesthetists in South Africa is not known. Objectives: The aim of this study was to assess financial literacy among anaesthetists in the Wits Department of Anaesthesiology and to identify demographic factors that could predict differences in financial literacy. Methods: This was a cross-sectional, contextual and descriptive study using an anonymous, self administered questionnaire. The questionnaire was an adaptation of the original used in the South African Social Attitudes Survey and was scored similarly. A mean financial literacy score was calculated for each anaesthetist using four domain scores (financial knowledge, financial planning, financial control and product choice and awareness) and used to make comparisons between demographic categories. Results: A total of 184 anaesthetists from the Wits Department of Anaesthesiology were included. The mean financial literacy score (0-100 scale) was 72. With the exception of White anaesthetists scoring higher than Coloured anaesthetists (p= .049), no other demographic category showed significant differences. Gender, age, relationship status and years of employment did not inform any enduring trend with regards to mean financial literacy scores. The mean scores for the individual domains were 79 for financial control, 76 for financial planning, 51 for product choice and 82 for financial knowledge. Between the domains, the mean financial knowledge score was higher than the mean financial planning score (p =.011). The product choice score was found to be the lowest (p<.0005) Only 35% of anaesthetists are confident in buying financial products and services by themselves while 8.2% of anaesthetists are very confident in their retirement planning. Anaesthetists who held an unsuitable financial product in their portfolio accounted for 40%, while 36% of anaesthetists experienced regret regarding financial decisions. It was also found that younger, junior, Coloured and Black anaesthetists have poorer financial preparedness. Conclusion: Anaesthetists in the Wits Department of Anaesthesiology have high levels of overall financial literacy, however, do not display adequate preparedness in planning for a secure financial future. A mandatory structured financial literacy programme during university, specialisation and fellowship training is recommended.Item Black Writings: The Modal Mixtape Sampling and Remixing the Ethos of South African Poor Theatre with the Film Medium(University of the Witwatersrand, Johannesburg, 2022-03) Sono, Sipho Alex; Jansen van Veuren, MockeLet’s imagine I’m standing in a record store aisle, with all these nostalgic “records” of film and theatre that I’m too young and perhaps too black to be drawn to, but still somehow feel connected to. Not only that, but I can’t shake the feeling that these records have informed me as a South African and could form new work in a strong way. I'm trying to make a “song”, a cohesive language for my practice as a filmmaker, with an underpinning interest, ethos and an understanding of South African Poor Theatre. In my hand I have a Grotowski “record”, called Towards Poor Theatre (1976), that is the main sample for my track. I’m also “digging through crates”, looking at the Theatre of the Oppressed by Augasto Boal (1974) and other theories of theatre in film, to mix together to make the song. I’ve been listening to tracks by Athol Fugard and Barney Simon, as sources of inspiration. As Pharrell Williams describes chords as “coordinates pointing us to emotion” (2019) , I have begun to think that maybe plays such Woza Albert (1971) and Sizwe Banzi is Dead (1972 ) and their recordings for BBC (1982 and 1983) can serve as chords and indicators to the direction for my filmic practice. Although you might not find a section entitled “methodology” in this paper, what you will find is that it is underpinned by practice based research methodologies, in the interest of Walter Mignolo’s epistemology disobedience. In this paper, I employ DJ Lyneé Denise’s concept of The DJ Scholarship (2013) as a research methodology, which sees the paralleling between the roles of the research to those of a DJ, borrowing ideas and recontextualising them . I sample theatre concepts, ideas and theories to mix and remix them and eventually form my own knowledge around my filmic practice. This notion of deejaying also exists in the research question itself, as it seeks to attempt a blending of two artistic disciplines. It is further carried in the way I approach film and storytelling, through the editing process, cutting, scratching, loop and rewinding for further indentation. This research further makes use of auto-ethnographic methods for meaning making and epistemic disobedience. These methods are employed through personal anecdotes and reflexivity as additive interrogators and informers to the research exploration. This research project also makes use of the personal, in the research film as a means to explore therapeutic processes for film as well as an exploration of the personal as a political enquiry. Auto-Ethnography functions in the crux of this research, it is an inquiry of the self, as a black “born free” South African and my relationship with Poor and Protest Theatre as an inherited artistic voice. As I stand in the middle of this record-store of theoretical frameworks and literature, I am also analysing the “records” which pick and sample. I am studying them and thinking about what they represent and what they indicate about me and the ethos of my filmmaking practice in a traumatised, post-apartheid South Africa . So let’s get to mixing.Item Bottom-half Intergenerational Mobility Among the Coloured Population in South Africa(University of the Witwatersrand, Johannesburg, 2023) De Kock, Tryston; Roberts, GarethI examined the intergenerational mobility of education among the Coloured population in South Africa between 1975 and 1990. I used the National Income Dynamics Study to measure intergenerational mobility among Coloured children born to parents at the bottom of the education distribution-this includes parents with an educational attainment lower than grade 10. I found across the whole population; the median rank of education is grade 10 – making grade 10 my middle point. I compared several intergenerational mobility indices with bottom-half mobility and look at the IGE and IGC indices for sons, as well as the summary statistics for the coloured, African, and White populations. I suggested that Coloured daughters born to mothers in the bottom half of the education distribution have experienced a decrease in upward mobility meanwhile upward mobility has increased for Coloured sons. However, I suggested Coloured daughters born to parents with educational attainment lower than grade 10 have a higher chance of increasing their educational attainment compared to Coloured sons. I also compared mobility estimates between Coloured children born in the Western and Northern Cape with Coloured children born elsewhere. I found that Coloured children born in the former have lower upward mobility compared to Coloured children born elsewhereItem Comparing the effectiveness of LSTM, ARIMA, and GRU algorithms for forecasting customer charging behavior in the electric mobility industry in Europe(University of the Witwatersrand, Johannesburg, 2023) Pelwan, Robyne ChimereForecasting, a powerful technique for unveiling potential future events, relies on historical data and methodological approaches to provide valuable insights. This dissertation delves into the domain of electric mobility, investigating the effectiveness of three distinct algorithms—Long Short-term Memory (LSTM), Autoregressive Integrated Moving Average (ARIMA), and Gated Recurrent Unit (GRU)—for predicting customer charging behavior. Specifically, it focuses on forecasting the number of charges over a 7-day period using time-series data from European electric mobility customers. In this study, we scrutinize the interplay between algorithmic performance and the intricacies of the dataset. Root mean squared error (RMSE) serves as a metric for gauging predictive accuracy. The findings highlight the supremacy of the ARIMA model in single-variable analysis, surpassing the predictive capabilities of both LSTM and GRU models. Even when additional features are introduced to enhance LSTM and GRU predictions, the superiority of ARIMA remains pronounced. Notably, this research underscores that ARIMA is particularly well-suited for time series data of this nature due to its tailored design. It contributes valuable insights for both researchers and practitioners in the electric mobility industry, aiding in the strategic selection of forecasting methodologies.Item Comparison of ultrasound and magnetic resonance Imaging findings in patients with suspected placenta accreta spectrum at Chris Hani Baragwanath Academic Hospital(2024)Background: Placenta accreta spectrum (PAS) is a serious condition that is increasing in prevalence with an increase in the caesarean section rate. This condition is associated with significant haemorrhage. Accurate diagnosis and adequate surgical planning are associated with favourable outcomes. Ultrasound and MRI are used in prenatal diagnosis of this condition. • Objectives: To compare ultrasound and MRI report findings with histopathology or surgical findings in patients with suspected PAS at Chris Hani Baragwanath Academic Hospital. To compare the diagnostic accuracy of PAS between the junior and senior (>5 years’ experience) radiologists’ MRI reports. Method: A retrospective comparison of 14 MRI and 18 ultrasound report findings of patients with suspected PAS were compared with histopathologic or surgical report findings. These imaging modalities' sensitivity, specificity, accuracy, true positive, true negative, false negative and false positive values were determined. The accuracy, sensitivity and specificity of MRI reports were determined based on radiologists’ experience. Results: Ultrasound correctly diagnosed PAS in 10/18(56%) of the patient reports. MRI correctly diagnosed PAS in 6/14(43%) of reports. Ultrasound reports had sensitivity and specificity of 90.9% and 28.6%, respectively, while MRI reports had sensitivity and specificity of 20% and 75%, respectively. The senior radiologists correctly diagnosed PAS in 3/7(42%) of reports, while junior radiologists correctly diagnosed PAS in 4/6(67.7%) of MRI reports. Conclusion: There was no statistically significant difference in the accuracy of Ultrasound and MRI in diagnosing PAS. There was no statistically significant difference in diagnosis of PAS between junior and senior radiologistsItem Condonation of non-compliance under section 67(1) of the competition act 89 of 1998(University of the Witwatersrand, Johannesburg, 2023) Humphreys, RussellThe Competition Commission has long sought to extend its powers to investigate and refer complaints to the Competition Tribunal for prosecution. Prior to the decision of the Constitutional Court in the case of the Competition Commission of South Africa v Pickfords Removals SA (Pty) Limited 2021 (3) SA 1 (CC) (the ‘Pickfords’ case), the power of the Commission to initiate investigations and therefore refer matters to the Competition Tribunal was limited by section 67(1) of the Act. Those accused of breaching the Competition Act 89 of 1998 have, in their defence, relied on the limitations of section 49B of the Competition Act - the procedure for initiating a complaint and section 67(1) which provides for a time limitation on initiating/referring a complaint to the Competition Tribunal. The Constitutional Court in the Pickfords case considered whether in light of section 34 of the Constitution, section 67(1) of the Competition Act should be interpreted as an absolute bar (a prescriptive provision) or procedural time bar (capable of condonation). Section 67(1) was, however, amended in 2018 to limit the referral of a compliant to the Tribunal to no more than three years after the practice ceased. This paper considers the statutory limitations on the Commission to initiate and refer complaints to the Competition Tribunal in terms of sections 49B, 50, 67(1) and section 58(1)(c)(ii) and to examine how these limitations have been by interpreted by our courtsItem Cost utility analysis of long acting muscarinic antagonists (LAMAs) as an alternative to long acting beta agonists (labas) for treatment of severe COPD in the South African public sector(2024) Thompson, PeggyObjective- The study purposed to estimate the cost-effectiveness of Tiotropium, compared with Salmeterol and Indacaterol for chronic obstructive pulmonary disease (COPD) patients within the South African public sector. Methods- A global Markov model was adapted for the local setting and developed in Microsoft Excel. Transition probabilities and data on costs, resource use and effectiveness were obtained from literature. Outcomes were calculated for 3-years in the base case, then extrapolated over a 10-year and lifetime time horizon. A 5% discounting rate was applied according to local guidelines. Cost-effectiveness was estimated as the incremental cost per quality adjusted life year (QALY). One-way and probabilistic sensitivity analyses were conducted to consider model uncertainty. Results- When compared with Indacaterol (300µg), Tiotropium was dominant (less costly and more effective) across all time horizons. Conversely, Tiotropium was not cost-effective when compared with Indacaterol (150µg) and dominated by Salmeterol over the 3- and 10-year time horizons. The resulting ICURs exceeded the estimated willingness to pay thresholds for all scenarios. The deterministic sensitivity analysis revealed the new intervention cost and utility for mild COPD impacted most on intervention cost effectiveness. Conclusion- Tiotropium was deemed not cost-effective at the proposed price, when compared to usual care for COPD. A price reduction should be considered, to determine the feasibility of displacing existing maintenance therapies. Indacaterol 150µg appeared more cost-effective at the current price and effectiveness demonstrated.Item Development of a multi-disease targeted next generation sequencing panel to study genetic aetiology of rasopathies(2024) Mudau, Maria MabyalwaWith Next Generation Sequencing (NGS), technologies it is now possible to screen a large number of genes simultaneously through massively parallel sequencing, significantly reducing costs and time generally associated with mutation screening. After an informal survey of the diagnostic needs of the clinicians in the Division of Human Genetics, National Health Laboratory Service (NHLS), it was established that the aetiology of genetic disorders called facial dysostoses, RASopathies and Cohesinopathies (FRASC) could be understood better using NGS. These are developmental disorders that are phenotypically different and are commonly referred to our genetic clinic, currently there is limited genetic testing for these conditions in South Africa. A NGS panel targeting genes associated with the FRASC disorders was designed and optimised. Upon successful optimisation the panel was then utilised to sequence samples from patients presenting with features suggestive of RASopathies. An overall detection rate of 56.6% (34/60) was obtained for all RASopathy patients sequenced in the current study. Detection rate of 46.7% (7/15) for neurofibromatosis type 1 (NF1) patients and 60% (27/45) for patients with non-NF1 RASopathies was obtained. No clinically significant variants were identified in 26 of the 60 patients (43.3%), two of the 26 had a VUS in the MAP2K1 gene. Seven patients of the panel negatives were successfully sequenced using whole exome sequencing (WES), one patient had a pathogenic variant and the rest had variants of uncertain significance identified. This is the first report profiling mutations and clinical features in patients with RASopathies as a whole in South Africa, compared to a study focusing on NS patients only. The detection rates obtained were comparable to other international studies using NGS, except for detection rate of LZTR1 and BRAF1 gene variants observed in Noonan syndrome patients. The (35/60) 58.3% (panel and WES) of patients with a disease causing variant identified in this study now have a molecular confirmation that they previously did not have. Our results show that a targeted panel could be an effective first-line diagnostic testing for RASopathies in SA. The development of the multi-disease targeted panel in the current study has contributed to the design of the 500 gene inherited disease NGS targeted panel (IDP) that is currently being utilised in our facility for diagnostic testing of various monogenic disorders.Item Disallowing the utilisation of an assessed loss: a survey of South African case law(University of the Witwatersrand, Johannesburg, 2023-01-26) Schreuder, Sharolta; De Koker, A. P.; Soni, FaeezaThe purpose of this report is to examine the circumstances in which the utilisation of an assessed tax loss can be disallowed. This research evaluates the provisions of section 20 of the Income Tax Act 58 of 1962 to the effect that the set-off of any balance of assessed loss incurred by a taxpayer (such as a company) in any previous year of assessment is admissible only against income derived by the taxpayer from carrying on a trade. The report focuses on how companies should have regard to the general legal principles laid down in the case law in considering whether they have satisfied the “carrying on [of] a trade” requirement in order to carry forward an assessed loss. The research suggests that taxpayers should also be aware that the South African Revenue Service (“SARS”) may nevertheless invoke the provisions of section 103(2) of the Act to disallow the utilisation of an assessed lossItem Disciplinary power and the proactive monitoring unit(2020) Flowers, Kevin EitanThe value of independent bodies charged with monitoring and improving the quality of financial reporting is becoming increasingly recognised around the world. The United States of America, United Kingdom and the European Union are examples of where such bodies exist. South Africa has created the Proactive Monitoring Unit (PMU). The PMU monitors the financial statements of companies listed on the JSE to ensure that they comply with International Financial Reporting Standards (IFRS).As most of these bodies are relatively new, there is limited research exploring how they function. This thesis aims to understand monitoring bodies better. Specifically, it will investigate if the PMU’s activities utilise Foucault’s disciplinary power to achieve results. 17 semi-structured, open-ended interviews with financial statement preparers, auditors, regulators and academics were conducted. The PMU is indicative of a partitioning mechanism used by the JSE in order to monitor and control the financial reporting space of listed companies. Preparers and auditors resemble well trained individuals who follow the PMU’s guidance without question. Respondents felt the constant gaze of the PMU which, combined with the negative reputational impact of an adverse review, leaves preparers and auditors fearful of the PMU. This anxiety seems to create a belief that preparers and auditors must present their financial statements as instructed by the PMU. This is one of the first theses which examines how external monitoring bodies function in a real-world setting. It adds to the limited accounting research which investigates why monitoring mechanisms achieve or do not achieve compliance. This is the first study to consider the functioning of external monitoring bodies in an African setting. This will provide insight into how monitoring bodies may best be constructed to improve corporate governanceItem Disinformation: exploring the nexus between politics and technology in Nigeria(University of the Witwatersrand, Johannesburg, 2022) Olaniran, SamuelOver the past decade, disinformation and social media hoaxes have evolved from a nuisance into a high-stake information war, exploiting weaknesses in our online information ecosystem. Although social media has the potential to strengthen democratic processes, there is increasing evidence of malicious actors polluting Nigeria’s information ecosystem during elections. Misleading narratives targeting candidates and political parties were picked up, liked, shared, and retweeted by thousands of other users during the 2019 presidential election campaign. Rooted in the theoretical lens of centre/periphery dynamics and equalizing and normalizing hypothesis, this study examines the networked nature of disinformation by identifying instigators, techniques, and motivations for spreading manipulated information around elections. While providing valuable data-driven insights drawn from a computational analysis of over 3 million tweets and a critical blend of qualitative framework, this study analyses the human agency and motivations behind online disinformation. The spread of falsities is coordinated in a way that “ordinary users” unknowingly become “unwitting agents” as “sincere activists” of concerted influence operations, a participatory culture that amplifies disinformation and propaganda. Agents’ participation in the “nairainfluenzer” industry is motivated by factors such ethnic and religious sentiments, poor economy, and low trust in news media. These findings broaden the perspective for examining top-down, orchestrated work as well as other types of coordination that stress how election-related disinformation heightens centre/periphery power dynamics. It further emphasizes that the systematic production and amplification of disinformation on Twitter represents a universal online behaviour not common “emotional-periphery” states.Item Efficacy of antero lateral thigh flap in head and neck reconstruction(2024) Machaka, Leah MokgadiBackground: Head and neck defects commonly from excision of cancer, require complex reconstruction. Our reconstructive goals are aimed at achieving safety, form and function. Escalation to the highest option on the ladder of reconstruction is obligatory. With the discovery of free anterolateral thigh flaps our reconstructive goals could be attained. Antero lateral thigh flap offered more to the reconstructive options than what it was initially described as. Antero lateral thigh flap not only gained popularity but also became the workhorse flap in head and neck reconstruction. Research has been done all over the world on the application of Antero lateral thigh flap but nothing is reported from South Africa. The aim of the study was to determine the efficacy of antero lateral thigh flap in head and neck reconstruction in plastic surgery department at Charlotte Maxeke Johannesburg Academic Hospital. Methodology: A retrospective medical record review was conducted at Charlotte Maxeke Johannesburg Academic Hospital which included all adult patients reconstructed with antero lateral thigh flap. Theatre and ward registration were used to identify the patients during the five-year period from 01 January 2014 – 31 December 2018. The number of patients with head and neck cancer during this period totalled 80, of which 33 met the study inclusion criteria: Adults with head and neck cancer reconstructed with antero lateral thigh flap. Main Outcome Measures – Flap survival, recipient and donor complications and length of hospital stay. Results: The study comprised 33 patients who had undergone a wide local excision, with/without neck dissection and reconstructed with antero lateral thigh flap. The mean age of the patients was 55.89 +/- 12.77 years. Most participants were male (n=24: 72.73%), female (n=9:27.27%), smokers (n=18: 56.25%) and 25 (78.13%) had SCC diagnosis, there were 15 (44.12%) patients with comorbidities and the average duration of the operation was 10.12+/- 2.65 hours. The most frequent anatomical site was the oral cavity (n=15: 50%). Maximum ICU stay was 2 days (n=31.93: 94%), The median hospital stay was 38 days with an interquartile range of 34-44 days. Post operation complications were experienced by 7 patients – recipient site complication (n=3,9%) and donor site complication (n=4, 12%), with a total flap survival of 94%. Conclusion: Our experience has given us the confidence to use this flap in a variety of head and neck defects. The antero lateral thigh flap is highly versatile, has a high survival rate and a low complication rate. Antero lateral thigh flap has found a permanent and highly valued place in head and neck reconstruction.Item Electrocardiographic features and characteristics of pericardial disease in children(2024) Coopoo, KevanyaIntroduction: There is little information regarding the aetiology, diagnosis and outcomes of pericardial disease in children on the African continent. The diagnosis is made easy using echocardiography, but it is not always available in a resource limited setting. The electrocardiogram (ECG) is an inexpensive and easily available tool that can be used to detect pericardial disease, but little data is available regarding its use in children. This study reports the characteristics of pericardial disease in children and their ECG features in a South African periurban setting. Methods: This retrospective descriptive study was conducted at a tertiary level hospital in Johannesburg, South Africa. The paediatric cardiology database was searched to identify all children with pericardial effusions from 1st January 1993 to 30th April 2019. Only patients that needed procedures or surgical intervention were selected for the study cohort, as it was expected that they would have ECGs available as part of their pre-procedure assessments. Available ECGs were collected and analysed for abnormalities. Other data such as age at presentation, sex, Human Immunodeficiency Virus (HIV) status, tuberculosis (TB) status, medications, pericardial fluid characteristics, details of pericardial surgical intervention and clinical outcome was also sourced from patient records and analysed. Basic descriptive statistics, such as percentages and frequencies was used for data interpretation. Results: Over the 26-year period, 724 cases of echo-proven PEs were identified. There were 79 patients who underwent interventions, which comprised the study cohort. Seventy-eight percent were over 5 years of age and the majority had large pericardial effusions. Infectious causes predominated, of which TB was the most common (60%). Forty-five percent were documented as HIV positive. The most common procedure performed was the insertion of a pericardial drain. Fifty-four percent of patients had resolution on follow-up, 4% had disease recurrence, 14% of the cohort died and 24% had unknown outcomes. The predominant ECG features in the 25 ECGs that were legible were those of sub-acute or chronic pericarditis, showing abnormal T-waves in 96% and sinus tachycardia in 80%. Other abnormalities were: decreased chest lead QRS voltages (52%), PR segment depression (48%) and decreased limb lead QRS voltage (40%), Less common findings were electrical alternans (28%), ST segment elevation (12%) and ‘Spodick’s sign’ (8%). Conclusions: The study showed that infectious causes, in particular TB, are the predominant causes of paediatric pericardial disease in South Africa. The majority of children, however, had complete resolution of their pericardial disease despite the need for invasive interventions. Although few ECGs were located and legible, all showed abnormalities with the majority displaying features of sub-acute or chronic pericarditis, suggesting that most children undergoing invasive treatment have later stages of pericardial disease. The few ECGs that were available for interpretation constitute a notable study limitation, but provide a basis for future studies on ECG changes in children with pericardial disease.Item Estimating skills in discrete pursuit-evasion games(University of the Witwatersrand, Johannesburg, 2023) Gomes, Byron John; Rosman, BenjaminGame Theory is a well-established field in mathematics, economics, and computer science, with a rich history of studying n-person, zero-sum games. Researchers have utilized the best computational power of their time to create computational players that are able to beat the best human players at complex two-player, zero-sum games such as Chess and Go. In the field of Reinforcement Learning and Robotics, these types of games are considered useful environments to conduct experiments about agent behavior and learning. In this research report we explore a subset of discrete skill-dependent pursuit-evasion games upon which we build a framework to estimate player skills. In this game environment a player’s skill determines the actions available to them in each state and the transition dynamics resulting from the chosen action. The game offers a simplified depresentation of more complex games which often have vast state and action spaces, making it difficult to model and analyze player behavior. In this game environment we find that players with incorrect assumptions about an opponent’s skill perform sub-optimally at winning games. Given that knowledge of an opponent’s skill impacts on player performance, we demonstrate that players can use Bayesian inference to estimate their opponent’s skill, based on the action outcomes of an opponent. We also demonstrate that skill estimation is a valuable exercise for players to undertake and show that the performance of players that estimate their opponent’s skill converges to the performance of players given perfect knowledge of their opponent’s skill. This research contributes to our understanding of Bayesian skill estimation in skill-dependent pursuit-evasion games which may be useful in the fields of Multi-agent Reinforcement Learning and Robotics.Item Evaluation of the extent of disclosure of the UN Sustainable Development Goals (SDGs) in integrated reports by 40 South African companies listed on the Johannesburg Stock Exchange (JSE)(University of the Witwatersrand, Johannesburg, 2023) Manack, Ilhaam; Maroun, Warren; Lange, YvetteIn a world where resources are finite, sustainable development is of utmost importance to ensure the survival of the world as we know it. Many of the crises faced by the world such as poverty, a lack of clean water, deforestation and pollution can be reduced and, potentially, resolved through contributions from public and private organisations. In actual fact, many of these organisations contribute to the problems at hand as a result of a lack of regulatory guidance on sustainable development. This report provides insight into the integrated reports of 40 JSE-listed companies using the process of content analysis to ascertain each company’s contribution to sustainable development, through aligning its corporate practices with achieving the UN Sustainable Development Goals (SDG). No guideline currently exists for preparing SDG-related disclosures to be presented in integrated reports. As a result, a disclosure checklist was created for this purpose. It was found that SDG-related disclosures are predominantly vague and minimal, ifthey were given at all. Additionally, companies tend to provide more SDG-relateddisclosures over time. This research contributes to a small body of existing research in the field of SDG disclosures in integrated reports. This study is the first study to analyse the extent of SDG-related disclosures in South AfricaItem Experiences of loveLife Trust telephone counsellors about the EWP employed within Gauteng(University of the Witwatersrand, Johannesburg, 2022) Mpekana, RebeccaGlobally, most Non-Profit Organisations (NPOs) do not prioritise employee wellness programmes (EWPs). NPOs’ funding is often allocated for rendering their primary programmes rather than improving their employees’ wellness. Employees in NPOs are left to devise their own means to best cope with work-related stress and challenges. Some employees rely on support from community-based organisations or their colleagues. loveLife Trust is a South African NPO that operates nation-wide. loveLife Trust recently introduced EWP to be utilised by its employees who are telephone counsellors. As of year 2022, loveLife Trust employs about 12 telephone counsellors. The loveLife Trust counsellors render psychological support to youth country-wide. Dealing with the youth’s presenting problems exposes the telephone counsellors to burnout and anxiety. This study aimed to explore how telephone counsellors experience the loveLife Trust EWP service. This was a qualitative study that allowed the participants to openly share their views. The total participants for this study were 12 telephone counsellors who were working on the toll-free line which is based in Gauteng. In addition, two key informants; the team supervisor and an EWP account manager, were interviewed. All participants were interviewed through ZOOM Cloud Meetings. A qualitative interview schedule that was guided by open-ended one-on-one interview questions was used for data collection. Thematic data analysis was used to derive different themes for the study. The aim of the study was to explore the experiences of telephone counsellors on EWP at loveLife Trust. The telephone counsellors are based in the call centre in Gauteng. The study revealed that telephone counsellors have not utilised the EWP as a way of support. The telephone counsellors prefer collegial support for taking care of their wellness. To spark interest amongst telephone counsellors to utilise the service, loveLife management should prioritise EWP awareness.Item Exploring segmental reporting in integrated reporting(2021) Mpete, ThatoThis paper explores the link between segmental disclosures in the integrated reports of the top 100 JSE-listed entities and integrated reporting quality (IRQ). A content analysis has been performed over 3 years to identify links between segmental disclosure in the integrated report and the annual financial statements. This paper analyses whether entities which have integrated segments throughout their reports achieve better IRQ. This paper also analyses whether the segmental disclosures within the integrated report point to the emergence of integrated thinking. The findings indicate that the segmental disclosure in the integrated report mimics that in the annual financial statements. In addition, this thesis finds a correlation between segmental disclosure and IRQ. Companies which integrate segment disclosure throughout the integrated report are also found to achieve better IRQ. The findings suggest that segmental disclosures which are integrated provide further insight into the value creation process and are indicative of integrated thinking. Integrated thinking can be evidenced by management’s understanding of the entity, disclosure consistency in the integrated reporting and annual financial statements and integration within the business model.