4. Electronic Theses and Dissertations (ETDs) - Faculties submissions
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Item A retrospective study of the biochemical and radiological profile of children with genetic hypophosphatemic rickets and their response to conventional treatment(University of the Witwatersrand, Johannesburg, 2023-11) Isaac, Nikhila; Thandrayen, KebashniObjectives: Assessing the biochemical and radiological profile of children with genetic hypophosphatemic rickets and their response to conventional treatment. Design: Retrospective descriptive study. Setting: Metabolic Bone clinic at Chris Hani Baragwanath Academic Hospital in Soweto, South Africa. Subjects: Children less than 18 years, attending the Metabolic Bone clinic from 1st January 2006 to April 2020, with genetic hypophosphatemic rickets, commenced on conventional treatment. Results: Seventy patients met the inclusion criteria. Majority of patients were black South African (n=54 (77%)). Positive family history seen in 32 (46%) patients. The patients were short statured with a mean height for age z score (HAZ) of - 3.4 ± 1.79. The mean calcium, phosphate, alkaline phosphatase, parathyroid hormone levels and median Thacher score was 2.3 ± 0.16 mmol/L, 0.84 ± 0.19 mmol/L, 776.6 ± 531 IU/L, 7.15 ± 4.8 pmol/L and 8 (4-8) respectively. Improvement on last follow up on treatment was seen in ALP (776 ±531 vs 525±232; p <0.001) and Thacher scores (8 (4-8) vs 2 (1-3.5); p =0.01) after 5 years, but no change in phosphate or HAZ. Conclusion: Conventional therapy for treatment of hypophosphatemic rickets is not associated with an improvement in HAZ despite an improvement in radiology and ALP. Adherence is a major challenge for the majority of patients.Item Assessment of genetic counselling and testing of patients diagnosed with invasive breast carcinoma in two South African breast units(University of the Witwatersrand, Johannesburg, 2023) Mukendi, Ilunga Valerien; Cubasch, Herbert; Nietz, Sarah; Rossouw, BiancaGenetic counselling and testing can be helpful and enable further management when a carrier is identified early. Mutations in BRCA 1/2 situated on chromosomes 17q21 and 13q12-13 are rare. BRCA 1/2 are tumour suppressor genes essential for preserving genomic integrity, and their mutations will lead to DNA repair deficiency and persistent impaired DNA replication. As a result, dysplasia and breast malignancy will occur. This study was conducted at Charlotte Maxexe Johannesburg Academic Hospital, the breast unit at Chris Hani Baragwanath Academic Hospital, the Division of Human Genetics at the National Health Laboratory Service and the University of the Witwatersrand. A total of 498 patients with breast cancer participated in the study. The study population was predominantly black (n=437; 87.75%), with 61 (12.25%) white patients. Most patients were in the 51-60 age group (n=134; 26.91%). There were 80 (16.06%) patients with a known family history of breast/ovarian cancer. Most patients (282; 56.63%) were not eligible for genetic counselling and testing. Of the 216 (43.37%) eligible patients, 39 (18.06%) received genetic counselling, 176 (81.4%) did not, and one (0.46%) refused counselling. All counselled patients received next-generation sequencing testing. Our findings show that next-generation sequencing is still underused in our health institutions. Most patients were not offered counselling despite meeting the criteria.Item The Political Economy of Energy Regulation in the Coal Mining Industry of Emalahleni(University of the Witwatersrand, Johannesburg, 2023-06) Selebi, Elton Jimmy; Matshabaphala, ManamelaThis study explores the perspectives on the political economy of energy regulation in the coal mining industry of Emalahleni. It seeks to discuss whether there are adequate steps within the political and economic sphere that regulates the efficient supply of electricity. The goals of this study are to ascertain the extent of regulation and policy formulation in the coal mining business in Emalahleni, South Africa; examine the reasons for decision-makers’ inaction in promoting a sustainable energy transition in Emalahleni, South Africa, and to identify political channels and platforms that can garner public and/or political support to speed the region's transition to sustainable energy. This research draws upon theoretical discussions centred on the following: The Agency Theory, Classical Political Economy, Keynesian Economics, and the Political Theory of Governance. Informed by an interpretivist paradigm, the qualitative research approach will be employed to explore the political economy of energy regulation within the study area. A non-probability sampling approach through the use of judgemental sampling was used to select the research participants, and the research method utilised interviews through the distribution of a questionnaire. A sample size of 20 comprised individuals from mining organisations in Emalahleni, Department of Mineral Resources and Energy Officials, CGS, Petroleum Agency SA, COSATU, and the Department of Trade Industry and Competition. The study noted that the political system has an impact on the energy and coal regulation markets at Emalahleni. It is recommended that an efficient energy resource policy and local governance are required to address the challenges of increased energy demand and pollution in South Africa.Item African financial markets and global uncertainties: nonlinearities, asymmetries, and information flow(University of the Witwatersrand, Johannesburg, 2024) Dadzie, Emmanuel; George, TweneboahThe global economy has witnessed rapid integration of financial markets, resulting in increased interdependence. This thesis investigates how global uncertainties or shocks impact African financial markets, focusing on both stock markets and currencies. The study examines how African markets have become more exposed to shocks, uncertainties, and spillover effects originating from other regions, particularly during crises and pandemics. Given the increasing significance of global policy shocks in investment decisions, portfolio design, and risk management, this research seeks to fill the gap in understanding the robustness of African markets in the face of such challenges. It employs advanced econometric models to capture nonlinearities, asymmetries, and information content flow within a time-frequency domain, addressing the underexplored areas of the literature. The thesis covers African stocks or equities markets and currencies. The selection of markets reflects the diverse economic landscapes and conditions across the continent. Prominent stock exchanges such as the Nigerian Stock Exchange, Botswana Stock Exchange, Egyptian Exchange, Tunis Stock Exchange, Namibian Stock Exchange, Moroccan All Shares Index, Ghana Stock Exchange, Lusaka Stock Exchange, and the Johannesburg Stock Exchange Africa All Share Index in South Africa have been captured. In addition to the stocks or equities markets, the choice of currencies also reflects the economic diversity and regional dynamics across the continent. These include the Egyptian Pound, the South African Rand, the Nigerian Naira, the Tunisian Dinar, the Ghanaian Cedi, the Moroccan Dirham, the Botswana Pula, the Mauritian Rupee, the iii Kenyan Shilling, the Namibian Dollar, and the West African CFA Franc. The global uncertainties or global shocks used in this thesis are the US Economic Policy Uncertainty Index, Oil Volatility Index, and Volatility Index. These indices are crucial indicators of economic instability and market sentiment and provide insights into the level of uncertainty surrounding economic policies, oil prices, and overall market volatility. The analysis covers 1 January 2010 to 31 December 2022 giving 3,379 daily observations for each variable. The thesis is organized into six chapters, with three self-contained empirical chapters. Each empirical chapter focuses on one specific objective or research question. The first empirical chapter examined the information flow between African stocks and global uncertainties using advanced analytical techniques. Employing the Complete Ensemble Empirical Mode Decomposition with Adaptive Noise method for data decomposition and the Rényi effective transfer entropy technique for information exchange estimation, the relationships between economic policy uncertainty, oil volatility index, CBOE volatility index, and African stock markets are investigated. The findings reveal both significant and insignificant positive information flows between US Economic Policy Uncertainty and African stocks across different investment horizons. Similar trends were observed with the oil volatility index and the CBOE volatility index, indicating a consistent pattern of information exchange. Importantly, no significant negative transfers were observed, suggesting a limited risk of contagion and high market resilience. Moreover, all three global uncertainty indices were identified as net positive information senders to African stocks across various investment horizons. iv The second objective investigates the effect of global uncertainties on the currencies of both oil-exporting and oil-importing African currencies. The Chapter reveals asymmetrical relationships with generally positive associations, suggesting currency depreciation during changes in global shocks. Employing the Variational Mode Decomposition technique, the time series data is decomposed to reveal underlying patterns and dynamics. The results of the quantile regression model reveal asymmetries in the effects of these shocks on currency rates, with generally positive associations suggesting currency depreciation amidst fluctuations in global uncertainties. The study highlights mixed effects across different quantiles and market conditions. Short-term, medium-term, and long-term analyses reveal the varying effects of global uncertainties on African currency rates, which provides revelations into the dynamics shaping currency movements in Africa. The third objective also applies the Variational Mode Decomposition technique and the nonlinear causal technique by Diks and Panchenko (2006) to investigate the effects of global uncertainties on the currencies of oil-exporting and oil-importing African countries, across various time frames. The findings of the robust nonparametric causal tests reveal interesting patterns in the relationships between global shocks and African currencies. Notably, the US Economic Policy Uncertainty demonstrates a significant causal impact on the Ghanaian Cedi, while other oil-exporting and oil-importing currencies exhibit varied responses to global economic shocks. The Oil Volatility Index exerts short to medium- term influences on specific currency rates, with differential effects observed between v exporting and importing countries. Similarly, the Volatility Index affects the returns of certain currencies, highlighting the connectedness between global uncertainties and African currency markets. The evidence of asymmetric effects of global uncertainties on African financial markets and the diverse exposure of oil-exporting and oil-importing economies underscore the importance of considering country-specific contexts and economic structures in analyzing the impact of global shocks on the dynamics of African markets. Efforts by monetary and fiscal policymaking fronts to enhance market integration and improve information dissemination mechanisms are crucial to help African financial markets better respond to global uncertainties while minimizing adverse effects. The thesis offers valuable insights for policymakers, investors, and corporate bodies navigating African marketsItem Strategic Approaches to Disruptive Innovations in Regulated Markets: Two Cases Of State-owned Electric Utilities(University of the Witwatersrand, Johannesburg, 2024) Bhugwandin, Kubeshnie; Carmichael, TerriBoth state- and privately-owned electric utilities are currently navigating a wave of disruptive innovations that are reshaping the energy sector. While the overarching goals of profit and shareholder value apply to both, state-owned utilities have a distinct set of challenges in that their objectives also encompass social welfare, economic growth, and national development. Thus, their survival is a matter of national interest. An interpretivist paradigm guided this research, and a qualitative multi-case study was used to investigate strategic approaches to disruptive innovations in the regulated electricity markets of South Africa and France. The theoretical interrelationships between Disruptive Innovation theory, Dynamic Capabilities and Ambidexterity were holistically explored within the regulated markets. The data comprised documentation and interviews with the electric utilities, Eskom and Électricité de France and the national energy regulators in each country. The study's key findings indicated that disruptive innovations are multi- organisational and multi-dimensional, impacting the industry at the macro- and meso-levels, transforming the entire ecosystem via concurrent interconnected actions. Hence, there are many pathways to disruption, and state-owned electric utilities must reposition themselves in the market and respond with multifaceted approaches. State-owned electric utilities are recommended to engage in coopetition strategies such as investing in disruptive innovations with start-ups and building strong partner interdependence via joint activities or investments to facilitate the exchange of resources and capabilities and build trust. This research recommends an integrated response when faced with a wave of disruptive innovations, e.g. (i) investing in an existing business to improve efficiencies and retain customers, or extending the life of power plants and converting coal-fired power plants to biomass technology, whilst at the same time (ii) adopting disruptive innovations which have emerged in the market to offer new products iv and services such as e-mobility, energy efficiency, solar photovoltaic and energy storage services and (iii) investing in continuous research and innovation to compete with disruptors such as the piloting of floating wind turbines and lightweight solar photovoltaic structures. Furthermore, ambidexterity and dynamic capability can be used as tools by electric utilities to strategise effectively under VUCA conditions. Dynamic capabilities should be built to support sensing, sensemaking, shaping, seizing and transforming the organisation to retain competitive advantages and market leadership. The study identified risk-taking, negotiating ability, and organisational agility as dynamic capabilities required to seize opportunities. The research also identified the ability to modify and reconfigure human resources, organisational structure, assets, processes and culture as dynamic capabilities required to compete and maintain market leadership. Lastly, this study presented an alternative pathway to achieve ambidexterity. Electric utilities can utilise a hybrid ambidextrous approach, which entails simultaneously combining different modes at both the meso and micro levels, such as (i) creating structural separation, forming intra and inter-organisational alliances, (iii) building dynamic capabilities to accelerate exploration activities, and (iv) establishing dual executive management roles. This study has made theoretical contributions by proposing a new definition of disruptive innovations for the electricity industry and has widened the domains for Strategy-as-Practice research by extending the levels of praxis from micro, meso and macro to include an industry level. This moves strategising actions beyond the firm to incorporate wider practices in society. Furthermore, the dynamic capability theory was extended to include sensemaking and shaping as micro foundations to respond to disruptive innovations and maintain competitive advantages. This finding also contributed to the understanding of the resource- based theory by providing a source of heterogeneity. In addition, the research suggested that simultaneous use of casual and effectuation decision-making logic can be a source of heterogeneity for firms. The study clarified that shaping v capabilities are used not only during sensing and seizing opportunities but also influences or shapes transformation activities of the firm. The ambidexterity view was extended by presenting an alternative combination of modes within the hybrid ambidexterity approach. Practically, this research suggests that an integrated approach should be implemented by state-owned electric utilities to respond to a wave of disruptive innovationsItem Essays on exchange rate movements and stock returns in emerging and frontier African economies(University of the Witwatersrand, Johannesburg, 2024) Atipaga, Umar-Farouk; Alagidede, Imhotep Paul; Tweneboah, GeorgeGlobal financial markets have recently undergone significant turmoil due to numerous factors, such as economic uncertainties, pandemics, geopolitical tensions, and extreme contagion. Unfortunately, African economies are not immune to these global developments and are often impacted by risk-off sentiment. As a result, these shocks have significant consequences for African exchange rates and capital markets. Due to the region's trade and investment dynamics, African economic policymakers rely heavily on exchange rate management as a policy tool. Additionally, capital flows in the form of equities are important for Africa’s growth agenda. The research explored four distinct, yet interconnected essays related to currency and equity movements in Africa, aiming to offer valuable insights into investment and policy considerations while enriching the existing literature. The first essay explored the connection between currency movements and equities in Africa. This approach departs from the usual VAR and GARCH models and employs a tool that accounts for time-frequency co-movements. This is critical for investment and policy decisions as it better explains which part of the sample period produces shocks. Given the recent market uncertainties, this study suggests that investors can determine the right investment horizon. The bivariate wavelet technique established a profound negative correlation at the upper end of the horizon, making room for diversification opportunities. With exchange rates playing a dominant leading role, it presents a case for policy considerations towards currency stability. The partial wavelet results revealed that investors should scale down to the short end of the investment horizon during crisis periods like COVID-19. In the second essay, the asymmetric linkages were modelled between stock returns of developed economies and African markets using quantile regressions along 0.05 quantile iii | P a g e intervals. The crux of this study is to determine the options available to holders of African stocks considering market integration. Having employed the U.S. and U.K. as proxy for advanced markets, we found diversification and hedging benefits from the two advanced markets for some African equities at different time scales. The quantile-on-quantile regression results revealed that both U.S. and U.K. stocks could offer safe-haven benefits for some African equities in extreme market conditions. The findings strongly project that investors making decisions to mitigate risks must appreciate the heterogeneity in the nexus between the advanced markets and African economies to arrive at optimal risk-adjusted returns The third essay applied transfer entropy techniques for the examination of information flows between advanced and African markets. Information content analysis is vital in the current investment and portfolio management dispensation. Findings from the information exchanges indicated that some African markets have led the market integration process ahead of their peers. This study compared significant periods of global interest, such as the Fed normalisation period and BREXIT. The results present important implications for risk management strategies and policy measures to anchor markets to withstand shocks. Due to the potential scales of investments from market integration with advanced markets, African policymakers are encouraged to champion this agenda. However, this requires the need to build economies to withstand shocks. Similarly, in the last essay, the information content was modelled between currencies of advanced markets and African economies. Exchange rate spillovers have significant implications for emerging and frontier economies due to the linkages between currency performance and other key variables. The essay examined information exchanges with the iv | P a g e world’s most liquid currencies over different crisis periods. The results possess essential implications for risk management strategies and policy frameworks, especially in this current period of heightened global uncertainties. Due to the spillovers in the currency market, African policymakers should be wary about the susceptibility of their currencies to global shocks.Item Sustainability Financing and Investment in Integrated Waste Management: Implications for the Circular Economy in Ghana(University of the Witwatersrand, Johannesburg, 2023) Agyapong, Daniel; Tweneboah,GeorgeThe transition to a circular economy has been a major global developmental agenda, as reflected in the 17 Sustainable Development Goals (Agenda 2030). In line with this, Ghana has adopted the practice of integrating circularity into its development objectives to promote sustainability, particularly in the waste management sector, which has gained attention for its potential in efficient resource mobilization and access to secondary raw materials. However, despite policymakers integrating sustainability into the development framework, financing and investments in circular economy activities remain underexplored. Adequate financing and investments can transform waste streams into profitable projects and useful goods, such as recycling waste into secondary raw resources for further processing, recovering valuable resources like energy and precious metals, or converting waste into fuel or electricity through biological or thermal treatment. The study examined sustainability financing and investment and implications for sustainable development in Ghana. The overarching aim of the thesis is to investigate the factors influencing circular economy financing and investment, the impact of such financing on circular economy practices, and the broader implications for the waste management sector in Ghana. The study is structured into three self-contained empirical chapters, each addressing specific objectives through distinct analyses. Chapter Three examined the determinants of circular economy financing and investment supply, emphasizing the moderating role of the financial environment. Chapter Four assessed the effect of circular economy finance and investment supply on the adoption of circular economy practices in the waste management sector. Chapter Five examined the implications of circular economy practices on the performance of firms in the integrated waste sector.Item Enablers and barriers to effective strategy implementation in a South African financial institution(University of the Witwatersrand, Johannesburg, 2023) Zikalala, ZaneleStrategy implementation forms part of the broader concept and critical aspect of strategic management which is practiced across many organisations in South Africa. However, it has been found through the abundance of literature that most organisations put more emphasis, focus on strategy formulation, and neglect strategy implementation. The number of existing strategy formulation frameworks supports this view, while scholars have not reached a consensus on the most effective frameworks for strategy implementation. Based on the high failure rate on strategy implementation, ranging between 60% and 90%, this exploratory study will seek to understand factors impacting effective strategy implementation in a South African context for a financial institution. Qualitative research was undertaken to further explore this study, wherein data was collected through an electronic survey from employees within the financial institution who specifically work in the Strategy Enablement Office. The data analysis yielded findings that identified five key factors impacting strategy implementation: leadership and culture, strategy implementation, employee understanding, regular feedback, and organisational performance. Out of these factors, the findings indicated that regular feedback and employee understanding were considered significantly important to strategy implementation. Leadership and culture and organisational performance had a positive impact but were not significant, according to the data collected for a specific financial institution. The study confirmed the importance of strategy implementation and the key factors that lie under it; however, the study also revealed that the organisation will need to put more effort into senior leadership involvement and provide regular feedback to employees during strategy implementation. Therefore, some recommendations put forward are to ensure senior leadership’s greater involvement during strategy implementation and to be provided with training interventions in this regard to mitigate the risk of nonchalant behaviour by senior management during the implementation phase. The study contributes to helping teams working in strategy enablement across the organisation, to gain insights on which factors to focus on and which ones are potential blind spots during strategy implementation to improve organisational performance.Item Expanding and Enhancing Medical Testing Laboratories in rural areas of South Africa(University of the Witwatersrand, Johannesburg, 2024) Tshavhungwe, Tshifhiwa; Murimbika, McEdwardThis venture aims to establish medical laboratories in underserved rural areas of Vhembe district in Limpopo, South Africa in order to address the critical need for enhanced healthcare services in rural areas of South Africa. With a population of 1,653,077, Vhembe has about eight private labs in semi-urban areas, along with public hospital laboratories. The venture proposal is driven by the recognition of significant challenges faced by rural communities, including limited access to diagnostic testing facilities and prolonged turnaround times for test results. Limited access to laboratories impacts healthcare outcomes significantly (CDC, 2018). Healthcare laboratories aim to address this gap by providing advanced diagnostic services. The proximity of our labs to rural communities improves Turnaround Time (TAT) significantly, a crucial performance indicator for laboratories (Cassim et al., 2020). Local laboratories minimise reliance on external facilities, reducing transportation costs and logistical challenges as well as the need for sample referral which in turn improves TAT. This improves healthcare accessibility and streamlines diagnostic services (Coetzee et al., 2022)Item Utilisation of liquefied natural gas as energy by heavy-duty vehicles in South Africa(University of the Witwatersrand, Johannesburg, 2024) Tlalang, KgosietsileThe transport sector in South Africa significantly contributes to greenhouse gas emissions, with over fourteen percent of the total emissions attributed to it. The reliance on fossil fuels, particularly diesel, for vehicular road transportation exacerbates this issue. High operating costs per kilometre of diesel negatively affect the sustainability of heavy-duty vehicle operations. To address these challenges, a conceptual framework was employed to investigate various factors influencing the decision-making process to adopt LNG as an alternative fuel. Qualitative research methods were utilised to gain insights into the owners’ environmental awareness, economic considerations, and long-term sustainability goals regarding LNG adoption. The findings reveal a growing interest among heavy-duty vehicle operators in transitioning to LNG because of its environmental benefits, cost efficiency, and long-term sustainability prospects. Key stakeholders such as vehicle manufacturers, fuel providers, and logistics services are actively exploring LNG solutions to enhance fuel diversity, reduce emissions, and achieve cost efficiencies. Volvo Southern Africa, a major heavy-duty vehicle manufacturer, is leading efforts to provide environmentally friendly solutions to the industry. Similarly, some logistics services providers are undertaking pilot programmes to explore alternative energy technologies as part of their commitment to environmental sustainability. The research underscores the potential of LNG to transform the heavy-duty vehicle sector by offering a cleaner, more sustainable fuel alternative. Analysis of the estimated payback period and net present value demonstrates the economic viability of LNG heavy-duty vehicles compared to diesel counterparts. However, to realise the full potential of LNG adoption in South Africa, investment in infrastructure for importation and distribution is crucial. Additionally, concerns about potential government levies and taxes on LNG need to be addressed to encourage its utilisation