4. Electronic Theses and Dissertations (ETDs) - Faculties submissions
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Item Exploitation of Natural Resistance Genes, Mutation and Phytosanitation to Eliminate Cassava Geminiviruses(University of the Witwatersrand, Johannesburg, 2024-09) Kung’u, Mercy Wambui; Nyaboga, Evans; Rey, ChrissieNot AvailableItem Analysis of Mining Taxation in South Africa(University of the Witwatersrand, Johannesburg, 2011-05) Shikwambana, CallousMining is one of the principal industries in the South African economy, and thus fulfils an important role from the perspective of the fiscus. Mining is a high-level risk investment which involves massive capital expenditure as well as prolonged periods of non-production of mining income. It is because of this that mining taxation receives special treatment. The term ‘mineral’ is central to determining whether or not a taxpayer can be regarded as being carrying on mining operations in South Africa. A mining process usually involves different stages before minerals are obtained, being prospecting and pre-production stages, followed by the production and post-production stages. Income is earned and expenditure is incurred in all the different stages in the life of a mine. The research report will critically evaluate what is meant by ‘mining and mining operations’ as defined in the Income Tax Act 58 of 1962 (‘the Act’). The research report concludes with an analysis and evaluation of how income earned and expenditure incurred in the different stages in the life of a mine are treated in determining the taxable income in respect of a mining taxpayer.Item The study of quaternary semiconducting chalcogenide nanomaterials for application as counter electrodes(University of the Witwatersrand, Johannesburg, 2021) Ngubeni, Grace Nomthandazo; Moloto, NosiphoHerein, the colloidal synthesis of Cu2ZnSnS4 (CZTS), Cu2ZnSnSe4 (CZTSe) and the first time colloidal synthesis of Li2ZnSnS4 (LZTS) and Na2ZnSnS4 (NZTS) nanoparticles respectively were investigated. All the nanoparticles were applied as counter electrodes in dye-sensitized solar cells (DSSCs). For the CZTS and CZTSe nanoparticles in particular, the effect of three substrates, namely, vitreous carbon (VC), indium tin oxide (ITO) and fluorine doped tin oxide (FTO) on the electrocatalytic properties including the overall performance of the solar cells were investigated. The CZTS and CZTSe were successfully synthesized and characterized with X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FT-IR), nuclear magnetic resonance (NMR), and ultra-violet visible (UV-vis) spectroscopy and transmission electron microscope (TEM) for the morphologies. CZTSe on glassy carbon (VC) had better electrocatalytic activity as compared to CZTS, however, the DSSCs from VC were poor due to the reduced transmittance of the substrate. On ITO and FTO, CZTS performed the best. Electrochemically, CZTS had the lowest series resistance and charge transfer resistance however had the largest exchange current density and limiting diffusion current thereby making it the best electrocatalyst. The DSSC using CZTS–ITO gave the best performance with the power conversion efficiency (PCE) of 3.62%. Conversely, for the LZTS and NZTS nanoparticles the effect of the lithium and sodium precursors and the ratio of the constituents e.g. Li:Zn:Sn:S and Na:Zn:Sn:S on the properties of the LZTS and NZTS nanoparticles, respectively were investigated. In addition, the effect of the substrates, that is, ITO vs FTO on the electrocatalytic properties as well as overall performance of the DSSCs were studied. Using the Li2S precursor, the XPS, 7Li MAS NMR and Raman spectroscopy confirmed the presence of lithium and the formation of LZTS. Since the Li2S source and the 2:1:0.25:2 ratio, resulted in the purest particles, these were therefore used as CEs in DSSCs for the first time. LZTS nanoparticles on ITO gave the best performance with 2.26% PCE. Similarly, the study of NZTS indicated that the NaCl regardless of the ratios used resulted in the formation of impurities as observed from XRD patterns. The presence of sodium and the complete formation of NZTS nanoparticles through 23Na MAS NMR, XPS and Raman v spectroscopy were investigated. The results indicated that the Na2S-based nanoparticles in the 2:1:0.5:4 ratio, yielded the purest NZTS nanoparticles. As such, these results indicated a PCE of 3.93%. The study illustrates that alkali metals (Li+ and Na+) can be used as the monovalent cation in quaternary nanoparticles, instead of the commonly used Cu+ transition metal with promising results as counter electrode materials in DSSCs. Notably, the NZTS nanoparticles illustrated a higher PCE to CZTS while LZTS had the lowest PCE. It must be however noted, that these results require further optimization to explore the full potential of these alkali metal-based quaternary nanoparticles.Item Investigating the Effect of Cholesterol Depletion on IL-6 Cytokine Induced Epithelial-to-Mesenchymal Transition in Colorectal Cancer(University of the Witwatersrand, Johannesburg, 2022) Aronson, Ruth Shifra; Kaur, MandeepColorectal cancer (CRC) is the third leading cause of cancer globally. Poor patient prognosis is attributed to late diagnosis and high metastatic potential of the disease. The process of metastasis usually favours the conversion between epithelial and mesenchymal cellular states, termed epithelial-to-mesenchymal transition (EMT). EMT has been reported to contribute to drug resistance, following treatments with chemotherapy, which allows for cancer recurrence and metastasis. Additionally, increasing evidence indicates the role of the cholesterol biosynthesis pathway in EMT progression. The lipid composition of epithelial cells compared to mesenchymal cells is distinct and cells that undergo EMT show an elevation in cholesterol levels to facilitate increased proliferation and oncogenic signalling. This study aimed to investigate the effect of cholesterol depletion in EMT induced CRC and explored how cholesterol depletion influences the susceptibility of EMT induced cells to the chemotherapy cocktail referred to as FOLFOX (5-fluorouracil and oxaliplatin). Results showed that following EMT induction by proinflammatory cytokine interleukin-6 (IL-6), in HT-29 cells, cellular cholesterol content increased by ~30%. Cholesterol depletion with compounds methyl-β-cyclodextrin (MβCD) and KS-01, in post-EMT cells, showed to reverse EMT phenotypic changes as noted by increased epithelial marker E-cadherin (by 46.9% and 55.3%, respectively), decreased mesenchymal marker vimentin (by 41.0% and 52.8%, respectively) and reduced invasive potential (by 43.0% and 47.8%, respectively). Interestingly, EMT induced cells displayed increased sensitivity to the FOLFOX chemotherapy, following cholesterol depletion, as observed by enhanced susceptibility to apoptosis (by 46.7% and 60.3%, respectively) and attenuation of multidrug resistance (by 80.6% and 71.8%, respectively). Ultimately, this study highlights cholesterol depletion to be a promising strategy for potential treatment of metastatic CRC.Item Institutional factors enhancing and affecting service delivery in Lekwa Local Municipality(University of the Witwatersrand, Johannesburg, 2024) Tsotetsi, BiotumeloThe discourse surrounding South African local governments often highlights deficiencies in the efficient and effective delivery of basic social services. This study was motivated by the absence of viable solutions to the persistent challenges facing service delivery in local municipalities, and the Lekwa Local Municipality was no exception. Situated in the Mpumalanga Province, the Lekwa Local Municipality serves as a compelling case study to explore the institutional challenges that both enhance and hinder service delivery. The municipality has grappled with significant administrative instability and a lack of political oversight. Consequently, its capacity to deliver services has been severely compromised. These institutional challenges have manifested in various forms, including bureaucratic inefficiencies, inadequate resource allocation, and a lack of strategic planning and implementation. As a result, the municipality has struggled to meet the needs of its residents and address pressing socio-economic issues within its jurisdiction. By examining the institutional factors contributing to these challenges, this study seeks to provide valuable insights into the complexities of service delivery in local government settings. By understanding the root causes of these issues, policymakers, stakeholders, and community members can work towards implementing targeted interventions to improve governance processes, enhance accountability mechanisms, and ultimately, strengthen the capacity of local municipalities to deliver essential services to their constituents. The Lekwa Local Municipality has witnessed unrest and protest, due to poor service delivery. The research employed a qualitative approach, utilizing a non-probability purposive sampling technique to select fourteen participants. This method was chosen deliberately to ensure that participants possessed relevant insights and experiences related to the research topic. Data collection was conducted through face-to-face semi-structured interviews, allowing for in- depth exploration of participants' perspectives, experiences, and opinions. The study's findings shed light on persistent challenges within the Lekwa Local Municipality despite the introduction of new leadership initiatives aimed at enhancing service delivery. A critical issue identified is the dire lack of leadership at both the political and administrative levels, resulting in a vacuum of oversight and accountability. This lack of effective leadership v has allowed self-interest and expediency to prevail, undermining the municipality's ability to fulfil its mandate. The study concludes by stating findings underscore the urgent need for comprehensive reforms within the Lekwa Local Municipality to address the root causes of poor service delivery. This includes strengthening leadership and accountability mechanisms, implementing transparent and accountable governance practices, and mobilizing resources effectively to ensure the delivery of quality services to residents. Only through concerted efforts to address these challenges can the municipality begin to regain the trust and confidence of its constituents and achieve meaningful improvements in service delivery outcomes.Item Exploring the digital divide in underserved communities in rural Mpumalanga, South Africa(University of the Witwatersrand, Johannesburg, 2024) Shandukani, Linda; Magida, AyandaThis research report explored the digital divide in underserved communities in rural Mpumalanga, South Africa, focusing on how owning a smartphone can help bridge the gap. Despite the widespread use of digital technology, financial constraints and limited digital literacy continue to create disparities, especially among marginalised populations. The study employed a qualitative research design, primarily through eight in- depth interviews, to explore how smartphones can impact digital inclusion and overall quality of life in these communities. The findings reveal a digital divide, particularly among young Black individuals, due to barriers in smartphone and internet accessibility. While ease of access to technology can enhance social and economic capital, challenges such as pricing and infrastructure limitations exacerbate disparities, perpetuating cycles of poverty and marginalisation.Item Examining oversight institutional failures in the North West Department of Health(University of the Witwatersrand, Johannesburg, 2024) Seeletso, Kenaleone; Motsepe, DikgangThe Legislatures in the local, provincial and national governments are mandated and bestowed with the powers by the Constitution of the Republic of South Africa of 1996 to ensure accountability by holding the executive accountable and effectively ensuring that there is oversight on the work of government. In order to execute the oversight function, the Legislatures use the Auditor General’s reports, guidance from the Public Finance Management Act (PFMA) and departmental policies. The study seeks to identify the systemic challenges faced by the oversight institutions in the North West Department of Health (NWDoH) that lead to failures in executing the oversight function. The research methodology used in this study is the qualitative approach. The population of the study is the oversight committee members from the North West Provincial Legislature (NWPL), NWDoH Office Bearers, former national SCOPA Chairpersons and public finance experts, and data was collected from the participants by using semi-structured interviews and official reports. The data collected from the participants indicated that the oversight committees cannot enforce accountability because their powers are limited to only making recommendations and their decision- making depends on their political allegiance. Political influence and lack of political will is at the centre of the systemic weaknesses within the oversight processes, hence, there is no accountability and consequence management and the non-compliance with the PFMA prevails. The study recommends that the standing rules be strengthened by diluting oversight committees with independent individuals so that committees can operate independently of party-political pressure. The study also recommends that the oversight committee be granted powers to enforce accountability and not just be limited to making recommendations.Item How the upgrading of informal settlements is measured by the multisectoral organizations(University of the Witwatersrand, Johannesburg, 2024) Pholo, Keneilwe; Blaser- Mapitsa, CaitlinThis master's research paper investigates the diverse methodologies employed by multisectoral organizations in measuring the success of informal settlement upgrading initiatives. Focusing on South Africa, the study focuses on what informal settlements upgrading is, the measurement and indicators utilized by these organizations to gauge the effectiveness of their interventions. Utilizing a qualitative research design, this study employs qualitative interviews to capture the breadth and depth of informal settlements upgrading and the measurement practices. Qualitative interviews with key stakeholders provided nuanced insights into the rationale behind chosen metrics, challenges faced in measurement, and the perceived outcomes of the upgrading efforts. Findings reveal consistent and coherent measurement practices across different organizations, reflecting the common goal of upgrading informal settlements instead of eradicating them as eradication could be interpreted differently and might cause distress to communities. The study explores commonalities and variations in metrics, shedding light on the factors influencing organizational choices in measurement frameworks. This research contributes to the scholarship on urban development by providing a comprehensive understanding of how multisectoral organizations approach the measurement of informal settlement upgrading. The insights gained from this study have the potential to inform best practices, enhance cross-sectoral collaboration, and guide the development of standardized metrics for evaluating the impact of multisectoral interventions on informal settlements.Item The impact of the use of e-Commerce on customer experience for retail in South Africa(University of the Witwatersrand, Johannesburg, 2024) Naidoo, Jaroshen; Mudau, Thanyani Normane-Commerce systems are rapidly changing how individuals shop, and they have provided many retail stores in South Africa with a new sales channel to service customers. With many organisations heavily investing in e-Commerce systems, the need to have end users adopting e-Commerce is vital for the success of the future of e-Commerce. Two areas that need to be examined include how customers currently use e-commerce systems and how e-Commerce use impacts customer experience. To understand the challenges, factors influencing e-commerce usage and its impact on customer experience were investigated. This study distinguished between basic and advanced utilisation of e-commerce systems. To understand the research objectives identified, an extended version of the Delone and Mclean IS Success model has been adapted to the study, which has been modelled as an e-Commerce IS success model. The factors influencing the advanced use of e-Commerce systems include information, system, and service quality. With e-Commerce being split into basic and advanced use, advanced use was focused on understanding how it affects customer experience. This data was collected through a survey distributed to end users of e-Commerce over LinkedIn. 159 respondents(n=159) provided insights into the factors, which included Information quality, system quality, service quality, basic use, advanced use, user satisfaction, customer experience and data quality. However, data quality was a factor that dropped during the Structural Equation Modelling (SEM), which was done through SPSS and AMOS. The research showed strong relationships between information quality and advanced use, system quality and advanced use, and service quality and advanced use. This confirmed the first objective of understanding the factors that impact the advanced use of e-Commerce systems in retail in South Africa. The next major result showed that advanced use had a higher coefficient to the basic viii uses relationship towards customer experience, and this translated to end users wanting to make use of the advanced features of e-Commerce systems to make decision-making and Key Performance Indicators (KPI) easier to achieve. In the findings, numerous contributions have been made, which include the factors that impact the basic and advanced use of e-Commerce systems. The effects of the basic and advanced use on customer experience and user satisfaction, which did not previously exist within the e-Commerce space, are also contributions identified in this study. Overall, this study helps organisations understand what end users and customers would want to use when using e- Commerce platforms in terms of features and how customer experience can be influenced by new technologies and features introduced into the e-Commerce system for retail in South Africa.Item The influence of artificial intelligence (AI) on personalised learning in the workplace(University of the Witwatersrand, Johannesburg, 2024) Msimang, Siphamandla; Alagbaoso, ManessahThis study investigates the influence of Artificial Intelligence (AI) on personalised learning in the workplace, set within the rapidly evolving landscape of digital technology integration in organisational learning strategies and environments. Addressing the gap in literature regarding AI's role in enhancing workplace learning experiences, this research utilises the Technology- Organisation-Environment (TOE) framework and Senge's Learning Organisation theory as its conceptual underpinnings. Through a quantitative methodology, data was collected from 391 participants across various industries via an AI-powered chatbot survey interface, focusing on employees' engagement in self-directed learning activities, perceptions of AI-enhanced personalised learning, and the factors influencing their engagement in workplace learning. The study reveals that employees perceive AI as an enhancer of personalised learning experiences in the workplace, with its adoption being significantly influenced by factors such as technological compatibility, organisational support, and a conducive regulatory environment. The findings offer an understanding of the multifaceted nature of AI in enhancing personalised learning experiences in the workplace, providing insights for future strategies and implementations in this evolving field. The conclusion draws attention to the transformative potential of AI in enhancing personalised learning within the workplace, advocating for its strategic integration to fully leverage its benefits. By aligning AI-driven learning tools with organisational cultures that prioritize continuous learning, organisations can significantly improve employee engagement, skills development, and ultimately, their competitive advantage in the digital era.