Mainstreaming equitable decision-making under uncertainty at the Water User Association level using a reallocation model in the Western Cape, South Africa

This thesis demonstrates how uncertainty can be explicitly incorporated into equitable decision-making in ungauged basins to support fair water reallocation strategies among conflicting uses and reduce vulnerability to water shortages. First, a methodological framework is developed to collect the required socio-economic data. Second, a role-playing game (RPG) is developed in collaboration with stakeholders to increase awareness and assess the implications of different allocation strategies and stakeholder actions. Thirdly, a reallocation decision-support system (Water-Sharing Tool) with dam storage and uncertainty is tested to inform strategic water planning under dry conditions. The study was carried out in collaboration with stakeholders in the upper reaches of the Koue Bokkeveld, Western Cape, South Africa. The study area is a winter rainfall area with commercial farming activities targeting the domestic and cross-border markets. Irrigation from numerous farm dams and run-of-river extraction compete with in-stream environmental protection targets for streamflow. The study area can be described as resource-poor in terms of institutional capacity, with water management decisions taken individually at a farm level. The key water users are the environment, farmers, lifestyle farmers (residents), and weekenders. The farmer group has three sub-groups: corporate-owned farms, family-owned commercial farms, and downstream less well-resourced farmers. Results from the user risk profiles show that the least influential actors reside downstream and are more vulnerable to water shortages, which could be attributed to upstream developments and their productivity-driven nature. The thesis pulls together the socio-economic data, the information contributed by the stakeholders during the RPG, uncertain natural runoff estimates, and water demands. It evaluates these using the Water Sharing Model to map water users’ vulnerability under four different management strategies and assesses equitable reallocation outcomes of the proposed strategies to different users. The magnitude and frequency of decision risks and the underlying uncertainty in the water supply are quantified. As expected, results suggest peak risks during months with the lowest streamflow, with negative implications for fruit production in the catchment. Results also showed the negative supply effects of upstream infrastructure development on downstream users and ecosystems. Game results with the farmers suggested different crop choices in dry periods between upstream and downstream farmers. Downstream farmers were surprisingly more willing to forego their dry season entitlements under water-sharing strategies that resulted in serious production losses upstream, prioritising social stability over their own profits. Farmers reflected on the game as an educational tool to enhance system understanding. The study confirms that decision-makers' understanding of the implications of water allocation decisions and the surrounding uncertainty is critical to meeting justice/fairness objectives.Thesis (PhD) -- Faculty of Science, Institute for Water Research, 202

Students’ changing accounts of chemical engineering: a longitudinal study in three countries

In this article we examine how students’ accounts of chemical engineering change during their undergraduate degrees and whether these changes were related to the educational intentions of their degree programs in two English, two South African and two US universities. Based on interviews with forty-five students over the course of their undergraduate chemical engineering degree, we found that initially most students did not know what chemical engineering was or thought it was about undertaking chemistry on a large scale. By the end of their degrees, most students had reached a watershed account of chemical engineering and saw it as about the design of large-scale processes of production. The changes in students’ accounts of chemical engineering appeared to be related to the educational intentions of their degree programs. We explore the implications of these outcomes for curriculum development in chemical engineering

An analysis of the role of tax legislation in promoting sustainability in the mining industry: a South African, Australian and United Kingdom perspective

The mining industry contributes significantly to South Africa’s economy, but is fraught with controversies due to its negative environmental, economic, and social impacts. Although tax measures are established to offset these negative externalities, the role of tax provisions in promoting sustainability within South Africa’s mining sector remains underexplored. The goal of this study is to analyse the tax provisions aimed at promoting sustainability in the mining industry in South Africa, Australia and the United Kingdom, in order to identify tax provisions applying in Australia and the United Kingdom that could be introduced into South African tax legislation to strengthen the sustainability of the mining industry. In addressing the goal of the research, the thesis outlines the socio-economic and environmental impacts of mining in South Africa, discusses the sustainability discourse surrounding the industry, and analyses and compares tax provisions promoting sustainability in South Africa, Australia and the United Kingdom. An interpretative qualitative research methodology was applied in the study. The research highlighted the significant environmental degradation caused by mining, including air and water pollution, biodiversity loss, and land degradation, while also noting the socio-economic consequences, particularly for local communities and vulnerable groups. South African tax legislation, such as the Income Tax Act, Mineral and Petroleum Resources Royalty Act, and the Carbon Tax Act, aim to promote mine rehabilitation, fair taxation, contribution to the fiscus, and a reduction in emissions. What is evident from the analysis of tax provisions in Australia and the United Kingdom is that tax measures go beyond mine rehabilitation, and address issues such as tax transparency, energy consumption, and community investments, promoting sustainability by balancing economic growth with environmental stewardship. The study concludes that current tax interventions primarily address environmental degradation while neglecting the social impacts of mining. Optimizing tax policies to enhance sustainability requires a comprehensive, balanced approach that addresses environmental, economic, and social aspects, including adopting practices from Australia and the United Kingdom to promote tax transparency, community investment, and environmental protection.Thesis (MCom) -- Faculty of Commerce, Accounting, 202

Examining the effects of small molecule tyrosine kinase inhibitors on glucose metabolism in skeletal muscle and liver cell lines in vitro

Diabetes mellitus is rising due to aging, sedentary lifestyles, obesity, and unhealthy diets, posing a global health threat. Due to increase in prevalence together with shortfalls associated with current treatment options, there is still a necessity for a continuous search of new pharmacotherapies. Small molecule tyrosine kinase inhibitors are drugs, used in cancer chemotherapy and have been shown to affect glycaemic control and metabolism variably. Studies have shown that tyrosine kinase inhibitors can alter glycaemic control and glucose metabolism, with some demonstrating hypoglycaemic activities whilst others showing hyperglycaemic properties. The mechanism by which tyrosine kinase inhibitors cause glycaemic dysregulation is not well understood, therefore, the clinical significance of these chemotherapeutic agents on glucose handling is also poorly documented. Aims and objectives: This study aims to elucidate how small molecule tyrosine kinase inhibitors affect glucose metabolism in C2C12 and HepG2 cells in vitro, including their impact on glucose uptake, AKT, GLUT-4, and IL-6 expression, GLUT-4 translocation, and alpha-amylase and alpha-glucosidase activity. Methods: In this study, C2C12 and HepG2 cells were seeded in well plates and the initial media glucose concentration was recorded. Cells were then treated with small molecule tyrosine kinase inhibitors; imatinib, dasatinib, axitinib, and erlotinib for 24 hours. Thereafter, the effect of the test drugs was assessed on cell viability, glucose uptake, expression of AKT GLUT-4 and IL-6, and translocation of GLUT-4. Furthermore, effects of the drugs were assessed on the activities of alpha amylase and glucosidase using calometric assays. Results and Discussion: Cells treated with small molecule tyrosine kinase inhibitors were viable after 24 hours. A concentration-dependent increase in glucose uptake in C2C12 cells treated with imatinib was observed as the concentration of imatinib increased. Axitinib, dasatinib, and erlotinib demonstrated glucose uptake levels comparable to the control across all concentrations. Small molecule tyrosine kinase inhibitors demonstrated an increase in GLUT4 translocation in the absence of insulin. GLUT4 expression was comparable in cells treated with small molecule tyrosine kinase inhibitors and the control. Small molecule tyrosine kinase inhibitors showed an increase in AKT expression. C2C12 cells treated with small molecule tyrosine kinase inhibitors were observed to have elevated IL-6 expression compared to the control. The HepG2 cells treated with erlotinib and imatinib demonstrated elevated glucose uptake while cells treated with axitinib and dasatinib were observed to have a lower glucose uptake. Treatment with dasatinib led to a decrease in Akt expression as concentration increased. Small molecule tyrosine kinase inhibitors demonstrated inhibition of alpha-amylase, while only dasatinib and axitinib showed inhibition of alpha-glucosidase. Conclusion: The results show that small molecule tyrosine kinase inhibitors impact glucose metabolism in C2C12 and HepG2 cells via their effect on GLUT-4 translocation and expression and AKT expression. Dasatinib showed promising potential with regard to antidiabetic capabilities. Further research is needed to better understand these mechanisms' effects on metabolic homeostasis and inform future therapeutic strategies.Thesis (MSc (Pharm)) -- Faculty of Pharmacy, Pharmacy, 202

Shifting from Development to Empowerment Through Eco-Creative Knowledge Transmission

Conventional definitions of development can be linked to socio-economic and cultural impositions of the Global North on developing societies. These development frameworks were inherited from the colonial system, which devalued local ways of knowing, being, and developing and continues to do so. Through a transdisciplinary or Boundary Crossing environmental case study that interrogates the use of heritage skills and knowledge for nature-based solutions relating to coastal shore regeneration, this chapter reflects on experiences of knowledge co-creation in the rural Eastern Cape Province setting of South Africa. Through the lens of African Musical Arts, which includes song and dance, storytelling, heritage skills, soundscapes, and more, this research seeks to shift the project perceptions of the scientists, engaged scholars, pracademics, practitioners and community researchers involved, from simple to multi-dimensional viewpoints. Using Traditional Cultural Expressions (TCEs) as catalysts, our goal is to emancipate transmission of knowledge from a developmental to an empowerment framework. Using the diverse disciplinary backgrounds of the authors, this chapter allows for a holistic examination of the development of an Audio Postcards exhibition, while interrogating the project centred on African theories, ecologies, and knowledge development

Our Ocean Is Sacred, You Can't Mine Heaven

‘Our Ocean Is Sacred, You Can’t Mine Heaven’ was a ground-breaking South African public storytelling initiative that not only emphasised the intrinsic and cultural value of the ocean but also served as a living-customary lore/law classroom. This exhibition challenged conventional archiving, promoting diversity, sovereignty and evolving ‘meaning-making,’ fostering inclusivity and justice-oriented documentation in ocean knowledge. The authors worked alongside Indigenous coastal communities and Small-Scale Fishers (SSF), who were aligned with movements defending the ocean against unchecked Blue Economy expansion in South Africa. The chapter delves into how artist-led practices, strategically embedded with legal research, played a pivotal role in a recent court ruling favouring Indigenous and SSF applicants. This victory renewed attention on ocean heritages in legal processes, highlighting the potential for expanding evidence ‘an-archives.’ The collaboration with coastal communities and SSF against unbridled ocean development used art to secure a court win, reshaping South African law and challenging norms in ocean development. This chapter explores art’s role in legal innovation, contributing to the ongoing struggle for justice and the decolonisation of blue economy narratives and processes in South Africa

Energy drinks and health policy implications in South Africa

Access restricted. Expected release date in 2027.Thesis (MSc (Pharm)) -- Faculty of Pharmacy, Pharmacy, 202

Bayesian inference for Cronbach's alpha

Cronbach’s alpha is used as a measure of reliability in fields like education, psychology and sociology. The reason for the popularity of Cronbach’s alpha is that it is computationally simple. Only the sample size and the variance components are needed and it can be computed for continuous as well as binary data. Cronbach’s alpha has been studied extensively using maximum likelihood estimation. Since Cronbach’s alpha is a function of the variance components, this often results in negative estimates of the variance components when the maximum likelihood method is considered as a method of estimation. In the field of Bayesian statistics, the parameters are random variables, and this can alleviate some of the problems of estimating negative variance estimates that often occur when the frequentist approach is used. The Bayesian approach also incorporates loss functions that considers the symmetry of the distribution of the parameters being estimated and adds some flexibility in obtaining better estimates of the unknown parameters. The Bayesian approach often results in better coverage probabilities than the frequentist approach especially for smaller sample sizes and it is therefore important to consider a Bayesian analysis in the estimation of Cronbach’s alpha. The reference and probability matching priors for Cronbach’s alpha will be derived using a one-way random effects model. The performance of these two priors will be compared to that of the well-known Jeffreys prior and a divergence prior. A simulation study will be considered to compare the performance of the priors, where the coverage rates, average interval lengths and standard deviations of the interval lengths will be computed. A second simulation study will be considered where the mean relative error will be compared for the various priors using the squared error, the absolute error and the linear in exponential (LINEX) loss functions. An illustrative example will also be considered. The combined Bayesian estimation of more than one Cronbach’s alpha will also be considered for m experiments with equal α but possibly different variance components. It will be shown that the reference and the probability-matching priors are the same. The Bayesian theory and results will be applied to two examples. The intervals for the combined model are however much shorter than those of the individual models. Also, the point estimates of the combined model are more accurate than those of the individual models. It is further concluded that the posterior distribution of α for the combined model becomes more important as the number of samples and models increase. The reference and probability matching priors for Cronbach’s alpha will be derived using a three-component hierarchical model. The performance of these two priors will be compared to that of the well-known Jeffreys prior and a divergence prior. A simulation study will be v vi considered to compare the performance of the priors, where the coverage rates, average interval lengths and standard deviations of the interval lengths will be computed. Two illustrative examples will also be considered. Statistical control limits will be obtained for Cronbach’s alpha in the case of a balanced one-way random effects model. This will be achieved by deriving the predictive distribution of a future Cronbach’s alpha. The unconditional posterior predictive distribution will be determined using Monte Carlo simulation and the Rao-Blackwell procedure. The predictive distribution will be used to obtain control limits and to determine the run-length and average run-length. Cronbach’s alpha will be estimated for a general covariance matrix using a Bayesian approach and comparing these results to the asymptotic frequentist interval valid under a general covariance matrix framework. Most of the results used in the literature require the compound symmetry assumption for analyses of Cronbach’s alpha. Fiducial and posterior distributions will be derived for Cronbach’s alpha in the case of the bivariate normal distribution. Various objective priors will be considered for the variance components and the correlation coefficient. One of the priors considered corresponds to the fiducial distribution. The performance of these priors will be compared to an asymptotic frequentist interval often used in the literature. A simulation study will be considered to compare the performance of the priors and the asymptotic interval, where the coverage rates and average interval lengths will be computed.Thesis (PhD) -- Faculty of Science, Statistics, 202

Exploring the impact of sub-ambient CO2 concentrations on Oxalis growth: implications for food sustainability among Pleistocene human foragers in the Greater Cape Floristic Region

Humans inhabiting the glacial refugia of the Cape Floristic Region during the Middle Pleistocene are believed to have relied on underground storage organs (USOs) as a crucial carbohydrate source. While previous research has highlighted the nutritional potential of these plants for early human gatherers, such studies are typically conducted under modern climatic conditions and do not account for the reduced plant productivity and USO yields associated with the lower atmospheric CO₂ concentrations characteristic of Pleistocene glacial periods. To evaluate the impact of CO₂ availability on plant productivity, I cultivated two Oxalis species—O. pes-caprae and O. punctata, both known to have been harvested by early foragers—under CO₂ concentrations ranging from 180 ppm to 400 ppm. Results showed that glacial-level CO₂ concentrations significantly reduced bulb production in O. pes-caprae and photosynthetic rates in both species. Using these findings to model Pleistocene foraging behaviour, I estimate that human foragers would have needed to spend an additional 8 hours gathering food to meet their daily dietary requirements of 2000 calories, suggesting the need for alternative food sources to supplement their diet. These findings emphasise the importance of considering historical plant growth conditions, particularly atmospheric CO₂ levels, when reconstructing past human diets. Failure to account for these factors may represent a significant gap in our understanding of human subsistence strategies during glacial periods.Thesis (MSc) -- Faculty of Science, Botany, 202

Three decades of change: exploring colonial legacies and shifts within processes of admission at South African Universities of Technology

Given South Africa’s complex legacy of inequality, access to higher education remains a priority for the government, higher education institutions and the public. And while significant progress has been made in terms of increased participation and expanded opportunities, particularly at Universities of Technology (UoTs), disparities remain. This particular type of institution has played a key role in contributing to the redress agenda through their less stringent admission requirements, but they remain underexamined in broader higher education literature. Despite these contributions, marginalised or working-class communities in rural and impoverished areas continue to face significant challenges in accessing higher education. Set against a global backdrop where similar patterns of admission have emerged, it becomes important to understand how and why the processes of admission in UoTs have emerged through the last three decades. In so doing, this study seeks to contribute to the conversation around social justice in higher education, offering insights that could reshape the understanding of why things are the way they are. This study draws on Critical Realism more broadly and the tools of Social Realism specifically to explore how South Africa’s particular colonial legacy remains one of many hidden mechanisms on which we build our reality. Using various documentation and qualitative data generated through interviews, which was analysed using Social Realism’s morphogenetic framework, I have endeavoured to tell the story of how, Universities of Technologies and their processes of admission have changed over the last three decades. In so doing I have shown, through using a metaphor of ‘The House Modernity Built’ how although much change has happened, hidden structures and cultures have worked to maintain a certain status quo, thereby constraining redress. This study has outlined the emergence of UoTs and their processes of admission as we understand them today. Through this I have presented an argument which suggests that the higher education sector continues to be structured in a hierarchical manner with UoTs located at the bottom. Mechanisms manifesting from a broader neoliberal environment, such as the higher education funding formula and global university ranking systems have placed UoTs in a position where they need to ‘catch up’, having consequences on the way in which processes of admission have been conceptualised. This has seen English becoming a marker of quality, and diploma offerings being replaced with degree equivalents carrying higher admission criteria, all of which work to compromise the redress needed in South African higher education.Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 202