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A computer vision framework towards automated scene understanding & analysis
(2025-03) Sarah-lee de Greeff
It is well-known that recent advancements in the domain of artificial intelligence and the increased capability of computer hardware have significantly advanced the field of computer vision – a field of study which enables computers to “see” and extract meaningful information from visual inputs, similar to human perception. A prominent application area within the domain of computer vision is scene understanding. Various powerful approaches towards scene understanding employ computer vision tasks to extrapolate semantic information about scenes, allowing computers to understand relationships between objects and their environments. Such computer vision tasks include object detection, recognition, tracking, pose estimation, and contextual reasoning. Most computer vision algorithms are deep learning based approaches but differ significantly in architecture. The computer vision tasks investigated in this thesis utilise architectures consisting of backbone, neck, and head architecture as well as alternative transformer architectures. Although computer vision applications are diverse, there remain fields that have not yet fully benefited from these developments. One such field is energy auditing – a process undertaken to evaluate and improve the energy management of buildings. In this thesis, a proof-of-concept framework is developed, capable of extracting information regarding appliances present in a given building scene or environment by employing object detection and object tracking tasks. The objective of the proposed framework is to train various object detection models and recommend the best-performing model for further implementation, in conjunction with object tracking models, to analyse video footage of environments needing to be audited. The framework facilitates the processing of raw data, training of object detection models with respect to the proposed data, and the deployment of the trained model with respect to unseen video footage. A structured literature review is conducted in this thesis to investigate the pertinent literature related to computer vision applications within the energy auditing domain. The fundamentals of deep learning, computer vision and energy auditing are also explored. The proposed framework is first applied to a subset of a publicly accepted benchmark dataset to verify its correct functioning. Subsequently, to further assess the framework’s performance and applicability, it is applied to a novel case study dataset provided by an industry partner, containing images of appliances common in an educational institution. The framework facilitates hyperparameter tuning to determine the best parameters for each model being trained. The best-performing model, RTDeTR, is then utilised to detect and track appliances of interest, providing information regarding the number of appliances present. The information attained by the models is essential for the environment’s energy consumption computation.
ACCOUNTING- AND VALUE-BASED PERSPECTIVES ON THE LINKAGES BETWEEN WORKING CAPITAL MANAGEMENT AND FINANCIAL PERFORMANCE
(Stellenbosch University, 2024-12) Liam Rory Johnson; Erasmus, P. D.; Mans-Kemp, N.; Stellenbosch University. Faculty of Economic and Management Sciences. Dept. of Business Management.
Financial managers are constantly searching for methods to direct scarce resources toward their optimal uses to enhance financial performance. Prior researchers who considered the relationship between working capital management (WCM) and financial performance focused on accounting-based metrics within developed countries. Value-based financial performance metrics remove some of the distortions associated with accounting-based metrics, thereby contributing to a cycle of sustainable value creation. Against this background, the primary research objective of this study was to assess the linkages between WCM and financial performance by incorporating accounting-based and value-based perspectives. Quantitative data were collected for a sample of companies listed on the Johannesburg Stock Exchange over the period 2006 to 2022, thereby including two crisis periods. When considering the outcomes of the panel regression analyses, various statistically significant relationships were noted between working capital and financial performance metrics, mainly from the value-based perspective for the entire sample. A statistically significant negative relationship was noted between net operating working capital (NOWC) and return on invested capital and the spread, respectively. In contrast, a statistically significant positive relationship was observed between NOWC and free cash flow (FCF). Furthermore, a statistically significant negative relationship was reported between the net operating trade cycle and FCF. Based on the reported results, the researcher recommends that managers, directors and investors include value-based measures when reflecting on WCM considerations instead of excessively focussing on short-term profitability. Furthermore, tertiary educators should emphasise the importance of sustainable value creation. As such, they can inspire future managers, directors, and investors to contribute to a more sustainable future.
Acute kinematic differences between barefoot and minimalist sandal running in male trail runners
(2022-12-01) Alexander, Justin Harry; Venter, Prof Ranel; de Waal, Simon
Adoption of technologies in the Saaf bases in Limpopo
(Stellenbosch : Stellenbosch University, 2024-12) Maselela, Tebogo Lazarus; Theletsane, Kula Ishmael; Khoza, Lindiwe Mhakamuni; Stellenbosch University. Faculty of Military Sciences. School for Organisation and Resource Management.
Society depends on military organisations to defend against both external and internal security threats and violent conflicts. Modern security threats are dynamic, especially in contemporary cyberspace and associated rapid technological advancement. It compels the South African military, as part of the security sector, to create innovative and fit-for-purpose solutions through the adoption and integration of equally advanced information communication technologies (ICTs). This study aimed to explore the adoption of technologies in South African Air Force (SAAF) military bases in Limpopo Province. A qualitative research methodology was employed within an interpretivist research philosophy. Data was collected through a focus group outline that utilized open-ended questions administered to engineering personnel in two SAAF units in Limpopo. The TAM underpinned the analysis of data. The findings revealed that members of the SAAF bases in Limpopo identified obstacles such as electricity load-shedding, questionable leadership practices, limited access to information, constraints in mobile communication networks, and security concerns about data hacking as significant challenges to technology adoption within the military. Additionally, low member morale in adopting new technologies is attributed to a lack of access to information, outdated communication systems, and lack of effective mobile network coverage. The study also found that perceived mistrust in the efficacy of technology and questionable ease of use significantly influenced the attitude of Limpopo SAAF members towards ICT adoption and usage. However, only perceived usefulness significantly influenced their intention to use ICT, suggesting that fundamental changes to the TAM may be necessary for SAAF members in Limpopo. While integrating ICTs into military settings presents challenges and opportunities, the discussion underscores the importance of structured learning experiences, foundational understanding, and leadership in navigating technological advancements within military environments. Addressing these key elements is essential in realising the full potential of ICTs in enhancing military capabilities and operations and contributing to national security.
An Afropolitan Quest: A Contemporary Jeweller’s Inquiry into Identity and Identification in Post-Colonial Africa
(Stellenbosch : Stellenbosch University, 2024-12) Mashange, Bongani Tendai Percy; Van Robbroeck, Lize; Terreblanche, Carine; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Visual Arts.
In this project, I engage my personal experiences as a cosmopolitan African subject belonging to multiple worlds. My body of work is in celebration of my cultural identity as complex and multifarious. I utilise a visual semiotics that contests fixed notions of cultural identity, that offer a means of expressing a need for recognition, and negotiate the parameters of the intersectionality of cultural and political citizenship. I use my art jewellery as a tool to question the concept of belonging in contemporary Africa. To examine my political subjectivity, I investigate contemporary writings on national and cultural identity politics. This research project not only adds to what is known and understood about identity and identification in postcolonial Africa, but it offers individuals who have struggled with racism, xenophobia, tribalism or any form of alienation, due to complex or hybrid identities, a different way of understanding and engaging their own identity as positive, thereby offering strategies to escape essentialist perceptions of identity and culture.
Alkaline amino acids in gold leaching: chemistry and application to Witwatersrand tailings
(Stellenbosch : Stellenbosch University, 2024-12) Tapfuma, Anthony; Tadie, Margreth; Akdogan, Guven; Stellenbosch University. Faculty of Engineering. Dept. of Chemical Engineering.
In gold processing, high-grade gold reserves with readily accessible gold deposits are being exhausted thereby increasing interest in the mining and processing of low-grade gold sources. The readily available low-grade gold sources are gold tailings, which are abandoned and abundant all over the globe. The processing of abandoned gold tailings is a crucial component of gold processing which can benefit economic and environmental perspectives. Currently, the cyanidation process is used in extracting gold from tailings due to its high selectivity and the ability to form very stable gold complexes, which leads to high gold recoveries. Despite the popularity of the cyanidation process, it poses environmental hazards, leading to the search for alternative lixiviants for the leaching of gold tailings. Amino acids have been identified as environmentally benign alternatives for leaching gold. Therefore, this study investigated the use of glycine, alanine, cysteine, and histidine in the leaching of gold, focusing on understanding the novel complexation/bonding chemistry, pure gold dissolution kinetics and the application in the leaching of Witwatersrand tailings. In fulfilling the investigations, a number of objectives were achieved and these included : (i) to assess the current status of amino acid utilisation in gold leaching, (ii) investigate gold-amino acid complexation through Fourier-transform infrared spectroscopy (FTIR), (iii) utilise Density Functional Theory (DFT) calculations to investigate gold-amino acid complexes, (iv) investigate pure gold dissolution conditions, (v) analyse gold electrochemical oxidation through linear sweep voltammetry, (vi) evaluate leaching of gold from Witwatersrand tailings, and (vii) propose a leaching mechanism for the study. The literature review covered the current status of amino acid use in gold leaching, looking at potential studies conducted and possible applications in secondary sources. The FTIR analysis showed that all four amino acids interacted with gold using the anchoring bonds on their carboxylic and amine ends. In addition, cysteine showed an extra bond using the sulphur in its R group. Furthermore, the FTIR work demonstrated that all four amino acids exhibited high bond shifts on the amine bond (NH2, NH3+) and carboxylic (COO-) bond at deprotonation pH compared to isoelectric pH. DFT calculations were done to predict the different complexes that different amino acids can form with gold. The geometric optimisation done showed that bonding of amino acids and gold was possible through donor atoms such as N, O and S. The bonding/complexation energy analysis also showed that the deprotonated amino acids can easily form complexes with gold compared to zwitterion, and this supported the FTIR finding. The thermodynamic behaviour investigations showed that the deprotonated amino acid complexes with gold were more stable than their counterparts. In addition to the FTIR interactions and DFT work, dissolution showed that gold dissolution was higher for the deprotonated system than for the isoelectric system (system containing the zwitterion). Moreover, the dissolution trend for the deprotonated amino acids was found to be cysteine> alanine> glycine> histidine, which was in line with the FTIR peak shift trend and the DFT bonding energy trend for the complexes. Furthermore, tests were done to improve gold dissolution, and these investigated oxidant type, amino acid effect, copper effect, oxidant concentration and pre-oxidation effect. Results showed that potassium permanganate was the best oxidant for glycine, alanine and cysteine, whereas hydrogen peroxide was the best oxidant for histidine. Furthermore, gold dissolution was enhanced with increasing amino acid concentration, copper concentration, and oxidant concentration, as well as the introduction of the pre-oxidation stage of pre-oxidising the pure gold. In addition, the electrochemical oxidation work also qualitatively supported the findings from the pure gold dissolution, showing that gold oxidation was enhanced by increasing variables investigated in the pure gold dissolution studies. Preliminary tests done on tailings leaching yielded low extraction leading to design experiments that improved the extractions. The Design of Experiment (DOE) was limited to alanine and glycine tests due to their promising ability in the pure gold dissolution and preliminary tailings tests. Results from the DOE showed a maximum 91.4% and 94.8% gold extraction upon using alkaline glycine and alanine, respectively at low solid liquid ratio after pre-oxidation of the tailing. Finally, the work gave a relationship between FTIR, DFT, gold dissolution and electrochemical oxidation of gold followed by proposing a mechanism for this work. The mechanism showed that potassium permanganate dissolved Au to Au+ in the pre-oxidation stage which could be a promising pretreatment method.
An analytical investigation of the physiochemical properties of crushed rifapentine administered to paediatricsby
(Stellenbosch : Stellenbosch University, 2024-12) Janse van Rensburg, Lisa Jane; Kellerman, Tracy; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Medicine.
Introduction: Tuberculosis (TB) remains a leading cause of mortality, particularly in paediatric populations where it accounts for a significant proportion of global TB burden. Rifapentine (RPT), a key antibiotic in TB treatment, poses challenges in paediatric care due to the lack of child-friendly formulations. Children under five years are often unable to swallow whole tablets, leading caregivers to resort to off-label practices like crushing tablets, which can significantly reduce the drug's bioavailability and therapeutic efficacy. This study aimed to investigate the physiochemical properties of crushed and dispersible RPT formulations and to explore potential interventions that could improve drug delivery and bioavailability in paediatric patients. Methods: A high-performance liquid chromatography (HPLC) method was developed and validated for the quantification of RPT. Three RPT formulations (Rifapentine 150 mg, Rifapentine 150 mg/Isoniazid 150 mg and Rifapentine 300 mg/Isoniazid 300 mg) were crushed and used to determine the aqueous solubility and stability in simulated gastric and intestinal fluid, with and without mechanical and chemical interventions. An extraction method was developed for RPT and used to evaluate its recovery in food and beverage products. The adsorption of crushed drug to a glass beaker and syringe walls was also analysed. The concentration and stability of a partial dose of a dispersible RPT tablet was assessed. Results and Discussion: The HPLC method developed for RPT quantification demonstrated robustness and accuracy across a calibration range of 0.156–10.0 μg/mL, with inter- and intra-day validations confirming precision within acceptable limits. Mechanical interventions and additives (cyclodextrin, NADES, ascorbic acid) improved RPT solubility, with effectiveness varying among formulations. Recovery of crushed RPT tablets from food and beverages was lower than the reference standard, with yogurt yielding the best results. Adsorption studies revealed that glass beakers minimized drug loss compared to syringes, and double rinsing further reduced drug lost due to adsorption. Stability in simulated gastrointestinal fluids varied among formulations, with ascorbic acid showing formulation-specific benefits. The new dispersible tablet formulation demonstrated challenges in achieving consistent dosing, with preparation method significantly influencing final concentrations. Conclusion: This study underscores the critical need for paediatric-specific RPT formulations that ensure adequate drug stability, solubility, and bioavailability. Crushing adult RPT tablets for paediatric use compromises drug efficacy, potentially leading to treatment failure and drug resistance. When crushing RPT tablets is necessary, using a glass beaker rather than a syringe for preparation and administration in liquid vehicles minimizes drug loss. Clinicians should advise caregivers to co-administer the crushed drug with high-fat foods to enhance absorption. Evaluation of the new investigational RPT dispersible tablet revealed challenges in achieving consistent and accurate dosing. The preparation method significantly influenced the final concentration, with dissolution in a glass beaker followed by a 5-minute equilibration period providing the most reliable results in the presence of INH. Future studies should evaluate syrups containing cyclodextrin, NADES, or similar carrier liquids which improve the solubility of the crushed RPT. This also provides an opportunity for flavour masking to make the formulation more tolerable to children.
Antibiotic-resistant Staphylococci in South Africa-A One Health Approach
(Stellenbosch : Stellenbosch University, 2024-12) Ocloo, Remous; Whitelaw, Andrew Christopher; Newton-Foot, Mae; Ziebuhr, Wilma; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Pathology (Medical Microbiology).
Staphylococci cause a wide range of infections in humans and animals, with Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis and Staphylococcus haemolyticus the most common Staphylococcus species implicated in healthcare and community acquired infections. The emergence and dissemination of antibiotic resistance (ABR) among Staphylococcus species has complicated empiric treatment practices and limited treatment options, leading to increased mortality. The World Health Organization (WHO, 2015) declared antimicrobial resistance a threat to the treatment of infections. The “One Health” initiative addresses health care challenges holistically by including human health, animal health and environmental health to achieve better public health outcomes. This approach is being adopted by the WHO to mitigate the problem of ABR and research across these sectors is required. This study investigated ABR rates and described the molecular resistance mechanisms and population structures of staphylococci from community, clinical and farm settings. This was achieved by employing both traditional culture and phenotypic antibiotic susceptibility testing as well as whole genome sequencing. A systematic review was conducted to understand trends, strengths, and limitations in the area of ABR in staphylococci other than Staphylococcus aureus (SOSA) in animals. The findings suggested that there is high tetracycline and penicillin resistance among SOSA organisms in livestock and companion animals in Africa. The review also highlighted the lack of strain typing of SOSA in Africa and that research was more focused on cattle. To employ a One Health approach, this study therefore included pigs, which are common livestock in the Western Cape province of South Africa, stool samples from healthy children in the community, and clinical isolates. S. haemolyticus and S. epidermidis were identified in all three settings, and S. borealis was identified from the pigs and the healthy community-based children, the first report of this species in Africa. High rates of tetracycline resistance were observed amongst pigs and human contacts on the pig farms. The majority of the healthy community-based children were colonised by methicillin resistant SOSA, and in the clinical isolates high rates of multidrug resistance were observed. The distribution of tetracycline resistance suggests that pig farms might be a “hotspot” for tetracycline resistance which is then transferred via the community with moderate resistance rates, to clinical settings with lower rates of tetracycline resistance. The tetracycline resistance gene tetK was seen across all selected settings in SOSA, as was the erythromycin resistance gene, ermC. No common strain types were circulating across all selected settings. However, certain S. haemolyticus strain types were identified in community and clinical settings. Our ability to conclude on genetic relatedness in the selected settings was limited by inconsistent species distribution and sample size. The findings suggest that S. haemolyticus is predominant in the community and might be spreading into the clinical and farm settings while Mammaliicoccus sciuri is predominant in the farm setting with potential dissemination into the community. Although the number of Staphylococcus aureus from the study was small, SOSA were more resistant than S. aureus with diverse antibiotic resistance genes; evidence of SOSA as a reservoir of ABR genes.
The Application of the 7C- Protocol to Assess Compliance with Public Procurement Prescripts in the Procurement of ICT Services in the Garden Route District Municipality
(Stellenbosch University, 2024-12) Damons, Salman; Quinot, Geo; Stellenbosch University. Faculty of Economic and Management Sciences. School of Public Leadership.
Understanding non-compliance with legislation that governs procurement in public entities necessitates an understanding of how these rules are experienced by those who implement them. This study investigates the implementation of public procurement policies in municipalities, with a specific focus on the procurement of Information and Communication Technology (ICT) services. The core research question investigates how public procurement rules, and their enforcement affect municipalities abilities to procure ICT services. The study assesses the implementation of public procurement regulations using the 7C Protocol to identify areas for improvement and propose measures to strengthen procurement procedures, boost transparency, and minimize corruption in Garden Route District Municipality. According to the research findings, the number of administrative difficulties faced by public procurement practitioners is an indicator of the efficiency and effectiveness of procurement policies. There are noted challenges in implementing supply chain management (SCM) and procurement legislation and procedures. Non-compliance with SCM policy and laws is because of poor procurement planning, a lack of knowledge and skills, insufficient operational capacity, outdated operating systems, and low staff morale and motivation. Furthermore, the study finds that effective leadership and management, integrated ICT solutions, and professionalisation of SCM personnel are all potential critical factors in addressing these challenges and improving procurement implementation. This research yields valuable insights for local governments seeking to enhance their procurement processes to ensure transparency, fairness, and efficiency in acquiring ICT services. Through incorporating the recommended measures, governments can navigate complexities and enhance service delivery to meet the evolving needs of their citizens.
Applied machine learning for radio galaxy classification and anomalous source detection
(Stellenbosch University, 2024-12) Brand, Kevin; Grobler, T. L.; Kleynhans, W.; Stellenbosch University. Faculty of Science. Dept. of Computer Science.
The classification of radio sources and the identification of anomalous sources play a vital role in the development of the understanding regarding various cosmological processes, such as the formation and evolution of galaxies and how they interact with their local environments. As the new generation of radio telescopes — such as the square kilometre array (SKA) — come online, a massive influx is expected with respect to the number of observations of radio sources that will be generated. This increase makes the manual evaluation and classification of radio sources by experts infeasible. Approaches have been considered that enable the general public to assist with these classifications. However, it is not clear whether these approaches will be able to keep up with the growing rates at which radio telescopes produce observations. Thus, a growing body of literature is investigating whether these tasks can be automated by applying machine learning models instead. In this thesis we extended the work conducted in the literature by further investigating the automation of morphological classification and anomalous source detection. We investigated two adaptations when applying convolutional neural networks (CNNs) to morphological classification, as these models have been shown to be particularly useful in this regard. We investigated the impact of standardising source orientation prior to CNN training and found that it leads to improvements in classification performance. However — apart from faster training times — it provided no benefits when compared to rotational augmentation, with rotational augmentation leading to better classification results.
Assessing Non-adherence in South African Women on Tamoxifen Treatment for Breast Cancer
(Stellenbosch : Stellenbosch University, 2024-12) Govender, Justine Tia; Kellerman, Tracy Ann; Decloedt, Eric Hermann; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Medicine.
Introduction: Adherence to tamoxifen is a major challenge in patients with hormone receptor-positive breast cancer. Endoxifen, tamoxifen’s main active metabolite, measured along with the parent drug, can be used as an adherence tool. A pilot study was undertaken to assess adherence in South African women by quantification of tamoxifen and endoxifen in plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Methods: The study recruited 20 oestrogen receptor-positive female breast cancer patients on tamoxifen. An adherence questionnaire was administered, clinical information collected, and plasma samples obtained for concentration measurement. A Shimadzu LCMS-8040 instrument was used to develop and validate a method to quantify tamoxifen and endoxifen in plasma. The transitions of tamoxifen and endoxifen: m/z 372 → 129; 91.1; 128 and m/z 374 → 223; 129; 152, respectively, were monitored in the positive ion mode. The LC-MS/MS method utilises an Agilent Poroshell 120 EC-C18 column and mobile phases of 0.1% formic acid in water (A) and acetonitrile (B) at a flow rate of 0.600 mL/min, together with a protein precipitation (PP) extraction method. Results and Discussion: Participant ages ranged from 32-73 years. Most participants (60%) had stage 4 breast cancer, with others distributed across earlier stages. Tamoxifen was prescribed primarily as palliative treatment (60%), followed by curative (35%) and prophylactic (5%) uses. The sample consisted mostly of preand post-menopausal women (45% each). Regarding comorbidities, 45% had none, 40% had one, and 15% had two. Only 2/20 participants were HIV positive. Tamoxifen and endoxifen plasma concentrations ranged from 11.7-340 ng/mL and 3.64-34.2 ng/mL, respectively. Objective non-adherence was low (5%), while subjective non-adherence was higher (45%). This resulted in failure to reject the null hypothesis of weak agreement between subjective and objective adherence measures. The LC-MS/MS method had quadratic regression weighted calibration curves (1/c) with concentration ranges of 4.69-600 ng/mL and 1.56-200 ng/mL for tamoxifen and endoxifen, respectively. Both analytes were stable under various storage conditions. No matrix effects were observed, and haemolysis at 2.0% did not affect analyte quantification. Average recovery was 89.6% for tamoxifen and 96.8% for endoxifen, with process efficiencies of 92.8% and 75.7%, respectively. Intra- and inter-validations met EMA (2011), FDA (2018) and ICH (2022) guidelines. Calibration standard (STD) % accuracies ranged from 97.6-101.7% for tamoxifen and 97.1-104.5% for endoxifen. Quality control (QC) % accuracies ranged from 104.5-113.2% for tamoxifen and 105.3-110.0% for endoxifen. Both analytes were stable in plasma through three freeze/thaw cycles and on bench for 6 h. Autosampler and re-injection stability was demonstrated at 8.00°C for 24 h. Conclusion: An LC-MS/MS method was successfully validated and applied to a clinical study to assess adherence in South African breast cancer patients. Poor agreement between subjective and objective adherence measures was demonstrated, emphasising the importance of direct measures in adherence assessment. The study highlighted the need to consider the measurement of tamoxifen and endoxifen concentrations to assess adherence and to optimise tamoxifen treatment.
Assessing the Coagulation System in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)
(Stellenbosch : Stellenbosch University, 2024-12) Nunes, Jean Massimo; Pretorius, Resia; Stellenbosch University. Faculty of Science. Dept. of Physiological Science.
Introduction: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating and chronic post-viral disease that is characterized by unresolved fatigue, post-exertional symptom exacerbation (PESE), cognitive dysfunction, orthostatic intolerance, and gastrointestinal disturbances, among other symptoms. ME/CFS shares significant overlap with Long COVID (LC), the post-viral disease associated with SARS-CoV-2 infection, in both disease presentation and etiology. A prominent feature of LC pathology is a dysregulated coagulation system, characterized by anomalous clot formation, hyperactivated platelets, and microclots. In ME/CFS, the coagulation system is understudied, and hence represents a gap in knowledge. Therefore, this study aims to assess whether the clotting pathology present in LC is mirrored in ME/CFS. Methods: To assess the coagulation system in ME/CFS, 29 ME/CFS (22 females, 7 males, mean age of 45.7 ± 14.9) and 30 age- and gender-matched control (21 females, 9 males, mean age of 49.1 ± 11.3) blood samples were analyzed. Viscoelastic analysis of blood samples was conducted using thromboelastography (TEG®). Platelet activity was assessed via fluorescent microscopy and the use of two fluorescent markers specific for platelet activation markers, glycoprotein IIb/IIIa and P-selectin. Thioflavin T (ThT) was used to visualize microclots using fluorescent microscopy. Representative micrographs and ImageJ processing were used to infer, crudely, concentration values of microclots. To validate this assessment, microclot concentrations were measured by a recently established cell-free flow cytometry technique. To identify differentially expressed proteins, 15 randomly selected ME/CFS and 10 control PPP samples were subject to liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. Results: Findings from the TEG® assessment indicate that over half of the ME/CFS WB samples fell out of the standard clinical range, representative of a hypercoagulable profile. This inference is further supported by the analysis of PPP, where the greatest differences were recorded in α-angle (p=0.0006) and maximum rate to thrombus generation (p=0.0001). Roughly half of the ME/CFS cohort demonstrated platelet hyperactivity as determined by spreading, whereas only a quarter of the cohort was positive for significant platelet clumping. Using fluorescent microscopy and ImageJ software, it was inferred that the ME/CFS group contains more than 10x the levels of microclots (0.70 [11.21]) than the controls (0.06 [2.23]) (p<0.0001). Appropriate quantitative analysis with cell-free flow cytometry determined that the ME/CFS group exhibits a microclot burden 5x (27808 [107203]) that of the control group (4898 [20709]) (p<0.0001). Furthermore, ME/CFS PPP sample contain a greater prevalence of large microclots (≤100-400μm2). The proteomics analysis identified 45 differentially expressed proteins. Importantly, proteins related to clotting processes – thrombospondin-1, platelet factor 4, and protein S – were implicated. Complement machinery was also downregulated, whereas lactotransferrin and protein S100-A9 were upregulated. Conclusion: Overall, this study demonstrates that dysregulated clotting processes are an aspect of ME/CFS pathology, and that these abnormalities in coagulation are similar to that observed in LC. These findings provide further overlap between ME/CFS and LC, and has the potential to guide future research and prompt investigations into haematological pathology in ME/CFS. Importantly, this study highlights potential systems and proteins that require further research with regards to their contribution to the pathogenesis of ME/CFS, symptom manifestation, and biomarker potential, and also gives insight into the cardiovascular risk experienced by ME/CFS individuals.
Assessing the effectiveness of municipal standard chart of accounts implementation : a case study of two low-capacity North West Province municipalities
(Stellenbosch : Stellenbosch University, 2024-12) Moloto, Morufa; Ajam, Tania; Stellenbosch University. Faculty of Economic and Management Sciences. School of Public Leadership
This study assesses the effectiveness of the implementation of the municipal standard chart of accounts (mSCOA) in South African municipalities. Two category B municipalities in the North West province were used as case studies. The Municipal Finance Management Act 53 of 2003 (MFMA) places emphasis on enhancing the quality of information to improve the relevance of financial reporting by municipalities. The Constitution of the Republic of South Africa (1996) provides that national legislation must prescribe measures to ensure transparency and expenditure control in each sphere of government by introducing generally recognised accounting practice (GRAP), uniform expenditure classifications, and uniform treasury norms and standards. The most recent reform introduced is the mSCOA which came into effect on 1 July 2017. The reform requires that there be a uniform and standardised financial transaction classification framework. This means that mSCOA prescribes the method (the how) and format (the look) that municipalities and their entities should use to record and classify all expenditure (capital and operating), revenue, assets, liabilities, equity, policy outcomes and legislative reporting. Phenomenology is the research paradigm adopted in this study. A total of sixteen (16) participants were selected through purposive sampling to participate in the study. Data was collected through semi-structured interviews. Thematic analysis was used to analyse the data, using the inductive approach. The knowledge of the objectives of mSCOA by the participants was the limitation of the study. Participant responses are limited to the level of involvement in the project implementation. The study found that, despite the requirements of mSCOA, municipalities in the case study are not mSCOA compliant as not all business processes have been implemented due to challenges ranging from budgetary constraints to human capital capacity challenges. Furthermore, lack of capacity contributed to the system vendors not being able to implement the (7) seven minimum business processes. The increase in the amount of unauthorised expenditure for the municipalities in the study between 2019/20 and 2020/21 financial years suggests that municipal officials are not budgeting, transacting and reporting in alignment with mSCOA. Therefore, the controls built into the mSCOA system, which are aimed at preventing overspending on a vote, can be overridden. The constant version updates of the chart of accounts by National Treasury continue to put financial burdens on municipalities. The mSCOA implementation should be regarded as a continuous learning process to ensure that all stakeholders tasked with implementation are conversant with the objectives and requirements of a complaint mSCOA system. Also, the National Treasury should implement more effective change management as an integral part of any project.
An assessment of the Assemblies of God, Ghana’s Vision 3000 in light of Venn’s Three-Self Mission Model
(Stellenbosch University, 2024-12) Ampofo, Mishael Donkor; White, Peter; Stellenbosch University. Faculty of Theology. Dept. of Practical Theology & Missiology.
The rapid growth of Pentecostalism in Africa has led to an increased interest in understanding effective mission strategies within Christianity. This study assesses the Assemblies of God, Ghana’s (AOGG) Vision 3000 church planting initiative in light of Henry Venn’s Three-Self (3S) mission model. The 3S model, emphasising self-governance, self-support, and self-propagation, has guided AOGG’s mission effort since its establishment in 1931. Vision 3000, launched in 2014, aimed to double AOGG’s churches from 3,000 to 6,000 by 2019. This ambitious project provides a unique opportunity to examine the application and effectiveness of the 3S model in a contemporary African Pentecostal context. The study employs a qualitative research methodology, utilising semi-structured interviews with 57 key stakeholders, including Vision 3000 committee members, executive leadership, pastors, and local church leaders. This approach allows for an in-depth exploration of the lived experiences and perspectives of those directly involved in implementing and experiencing the initiative. Data was also gathered from official reports and relevant literature, providing a comprehensive view of the project’s development and outcomes. The research utilizes Basel’s Vertical Missionary Approach theory as its theoretical framework, offering a lens through which to analyse the holistic nature of AOGG’s mission efforts. The study reveals that Vision 3000 achieved significant success, planting 2,117 new churches and revitalizing evangelistic zeal and evangelical mindset among AOGG members. This numerical growth was accompanied by a renewed sense of mission and purpose within the denomination. However, the research also uncovers several challenges that emerged during the implementation of Vision 3000. These include difficulties in achieving financial self-support in economically disadvantaged areas, particularly in rural regions. And the complex task of balancing centralized oversight with local autonomy. The study highlights the intricate intersection of the 3S model’s implementation with Ghanaian cultural, economic, and social realities, demonstrating the need for ongoing contextualization of mission strategies. This research makes a significant contribution to the field of missiology by providing a nuanced analysis of the 3S model’s application in a specific African context. It goes beyond merely assessing the model’s effectiveness to propose a “3S plus” framework that incorporates self-theologizing and self-missionary components. This expanded model reflects the growing recognition of the need for indigenous theological reflection and cross-cultural mission engagement within African Christianity. The study also offers practical measures for contextualizing the model, including integrating traditional leadership structures and developing community-based financial models that resonate with Ghanaian cultural practices. The research concludes that while the 3S principles remain relevant in contemporary African mission contexts, their application requires ongoing contextualization to address local realities effectively. It demonstrates that successful mission strategies in modern Africa must strike a delicate balance between maintaining fidelity to universal Christian truths and deeply engaging with local contexts. This balance is crucial for developing authentic, sustainable, and culturally relevant expressions of Christianity. This study provides valuable insights for both scholarly research and practical mission strategies. As African Christianity continues to play an increasingly prominent role in global Christianity, understanding effective models for church growth and sustainability becomes ever more critical. The findings of this research offer a roadmap for other denominations and mission organizations seeking to implement large-scale church planting initiatives in Africa and other developing contexts. By examining the successes and challenges of Vision 3000 through the lens of the 3S model, this study contributes to ongoing discussions about indigenization, contextualization, and the future of mission in Africa. It sets the stage for further research into the long-term sustainability of rapid church growth initiatives, the role of technology in mission, and the development of truly African expressions of Christian theology and practice.
Assessment of Uncertainties Associated with the use of Alternative Satellite-Based Rainfall Estimates in Pitman Modelling
(Stellenbosch University, 2024-12) Kibii, Joshua Kiprotich; du Plessis, J. A.; Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering.
South Africa is a semi-arid water-scarce country experiencing increased climatic variability and hence the management of its water resources is important to the livelihood of its population. For effective management, there is a need to have a robust system that allows for continuous monitoring and simulation of the available water resources. However, the number of suitable observation stations in South Africa has been observed to be on a declining trend over the past few decades. This impedes the efficient management of water resources. South Africa makes use of the WR2012 database as the reference in the management of its water resources. The database contains at present monthly flows for the period 1921-2009. This database has been outdated for more than a decade and continues to age. The WR2012 report recommends a continuous update of this database. However, the cost and sustainability of a continuous update, given the declining trend in available observed rainfall data, is challenging. This research seeks to find a solution to the identified ever-increasing challenge of declining rainfall datasets. This research identified the availability of easily accessible satellite-based rainfall data products as an alternative to the dwindling observed rainfall data, for the simulation of hydrological flows in the Pitman model. It then developed a CHIRPS-based Pitman model framework, which builds on the existing experience and knowledge of the Pitman model and CHIRPS (Climate Hazards Group Infrared Precipitation with Station data). The developed framework aimed at providing an alternative dynamic, quantifiable and up-to-date rainfall database while simplifying the process of simulating flows by removing the bottlenecks associated with data accessibility. The outcome of this research also focused on improving credibility, hence confidence in the use of CHIRPS-based simulated flows, for efficient water resources management, by assessment of associated uncertainties. The successful complementary use of CHIRPS rainfall estimates for simulating flows in this research thus provides a positive advancement towards embracing modern technology in the monitoring, simulation and management of water resources for South Africa. In performing this research, study drainage regions (G, B, V & L) were selected based on the existing primary drainage regions and rainfall zones of South Africa. Drainage region G belongs to the winter rainfall zone, drainage region L ‘All year’ rainfall zone, while drainage regions B and V belong to the summer rainfall zone. These rainfall zones have different rainfall mechanisms influencing how CHIRPS estimates correspond to observed rainfall. However, CHIRPS estimates illustrated a strong correlation (R2 > 0.7) in all the study drainage regions apart from drainage region L, experiencing an ‘All-year’ rainfall. The relationships between CHIRPS and observed catchment rainfall were used to adjust CHIRPS data. Calibrated CHIRPS data was then used in setting up and running the Pitman model. Calibration (1981-2009) and validation (2010-2019) were done on the Pitman model and results indicated good similarity between observed flows and simulated CHIRPS-based flows for the period of analysis. Eight hydrological indices were identified and used in assessing the ability of the simulated CHIRPS-based flows to reproduce different aspects of observed catchment hydrological responses. Using a ±15% uncertainty window, hydrological indices were evaluated and CHIRPS-based flows illustrated 78%, 73% and 80% suitability for drainage regions B, V and G respectively. Drainage region L had suspect results owing to the poor quality of data from the available gauge stations. Further, climate change simulations were done in representative quaternary catchments in study drainage regions B, V & G. The Coupled Model Intercomparison Project-Phase 5 (CMIP5) climate change data was downloaded and using a baseline scenario of 1981-2019, climate change signals for the near (2021-2060) and far (2061-2099) future scenarios were computed. The climate change signals were then used to adjust input climate data for the Pitman model and simulate climate change-induced flows. The results of climate change analysis illustrated a general decrease in simulated flows ranging from -0.45% (RCP 4.5, 2061-2099) in drainage region B to -40.31% (RCP 8.5, 2061-2099) in drainage region V. These results are in concurrence with previous research findings towards a consensus of a drier climate change future for South Africa. This research finds CHIRPS-based rainfall estimates to be a suitable alternative to the decreasing observed rainfall data and recommends it for use in the Pitman model simulation of observed and climate change flows for South Africa for the effective management of the available water resources. A novel contribution to the water resources of South Africa is made by this research in providing a framework that allows for the collaboration of the already published WR2012 data with CHIRPS estimates in generating updated flows and climate change-induced flows in a simplified process.
Audience trust in journalism: an exploratory case study of the youth in Philippi East
(Stellenbosch University, 2024-12) Ginya, Sive Faith; Wasserman, Herman; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Journalism.
The South African mainstream media has been criticised for catering to the elite audience to generate revenue while neglecting the realities of the citizens who live in townships and informal settlements. It has been asserted that many black, poor young South Africans do not recognise the stories of their communities in the mainstream news media. This study explored the experiences of the youth between the ages of 18 to 35 years in Philippi East. The study examined whether these youths find the news content of the South African mainstream media relevant to their lived realities, and if they feel like they are represented in the news content. The researcher conducted a thorough literature review looking at the different aspects of trust in journalism, the South African media landscape, the role of the South African news media, and criticism of the South African news media. The researcher utilised the folk theory of trust in journalism, which refers to the popular existing beliefs that the audience or the public have about journalism, and the place theory as this study's theoretical points of departure. The study employed the qualitative exploratory case study design to gain an in-depth understanding of the perceptions of these youth and collected data using semi-structured focus group interviews and individual interviews. The non-probability sampling procedure was employed to recruit and select participants. The researcher used inductive thematic analysis to analyse the data collected. The study found that the youth in Philippi East trust the news media as an institution that educates and informs the public about things happening around the world and in their communities. However, the Philippi East youth feel like they are not well represented in the news content of the South African mainstream media because the media only focuses on the mass shootings and seasonal floods that occur in Philippi East and excludes the art and educational events hosted in this community. In addition, these youth expressed confidence and satisfaction with the accuracy of the stories shown on the news about Philippi East. Finally, the study found that the youth in Philippi East expressed different views on whether they find the news content relevant to their lived realities. While some said they find the news content of the South African mainstream media relevant to their lived realities some said they find the news content irrelevant to their experiences claiming that the news media focuses on stories of rich people, and political content and neglects the realities of township residents.
Automated Pre-impact Fall Detection
(Stellenbosch : Stellenbosch University, 2024-12) Swanepoel, Mia; Coetzer, J.; Stellenbosch University. Faculty of Science. Dept. of Applied Mathematics.
The global population is aging rapidly, with individuals aged 60 and older now outnum- bering children under five. As a result, age-related injuries, including falls, have become increasingly common. Falls are the second leading cause of injury and death in the elderly. Systems such as cameras and wearable devices have been developed to monitor movement and detect falls. Research is now focusing on detecting falls before impact to enable possible interventions, such as wearable airbags, to reduce injuries. Current systems use methods like thresholding techniques and machine learning models to detect falls before they occur. This study examines various models that utilise time series data from a wearable device to detect falls before impact. The models include a thresholding technique, a support vector machine (SVM), a convolutional neural network (CNN), a convolutional long short term memory (ConvLSTM) network, a transformer, and the state of the art iTransformer. The data used in this study to train and test the models is the KFall dataset which includes 2729 activities of daily living (ADLs) and 2346 falls. The ConvLSTM model achieved the longest lead time of 391 ± 109 ms and the largest area under the receiver operating characteristic curve (AUC) of 0.94 as well as the best sensitivity and specificity trade off. The iTransformer showed promising results with an AUC of 0.84 and lead time of 375 ± 111 ms as well as a notable specificity of 91.22%. This research demonstrates the capability of a thresholding technique and deep learning models to accurately detect falls before impact in order to improve reaction time and reduce fall-related injuries.
Automatic orthography standardisation for under-resourced languages
(Stellenbosch University, 2024-12) Barends, Umr; Niesler, Thomas; Stellenbosch University. Faculty of Engineering. Dept. of Electrical & Electronic Engineering.
This work addresses the normalization of the orthography of a severely under-resourced language, taking as a specific example the West African language known as Bambara. One aspect of the lack of resources for such languages is that spelling and orthographic conventions are not firmly established. This for example leads to variations in how speech is transcribed by mother-tongue speakers, which in turn leads to inconsistencies in the annotations found in a speech corpus. According to our investigation, there is no data available for the normalization of the Bambara language other than the very small corpus used in this work. To our knowledge, this is also the only corpus of transcribed Bambara speech. Normalizing the spelling of Bambara spellings is important for systems such as ASR or text to speech, where more consistent spellings equate to better performance of such language model based systems. The baseline method, known as anagram hashing, uses word anagrams and word n-grams to perform the normalization. These methods have been used by other researches to normalize historical text to modern spellings. In addition, we determine the performance that can be achieved by applying the machine learning methods: softmax regression, LSTM and bi-LSTM. Our experiments indicate that the neural network models out-performed the anagram hashing algorithm on the task of normalization of the Bambara orthography. We also found that word-level models performed better than character-level models. Among the machine learning models, the softmax regression model performed best at normalizing the Bambara orthography. We conclude that it is possible to perform automatic normalization of orthography using machine learning models that is superior to the current state-of-the -art, but that the small size of the traning set does not allow the recurrent architecture to surpass the performance of softmax regression.
Becoming and Unbecoming: Black Students’ Identity Paralysis at Stellenbosch University
(Stellenbosch : Stellenbosch University, 2024-12) Lefika, Jimmy M.; Painter, Desmond; Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Psychology.
This is a qualitative, exploratory study of Black students’ self-reports and narratives of their perceptions and experiences of being students at Stellenbosch University, a Historically White Institution (HWI): how they navigate and negotiate space and a sense of self in the context of historical and contemporary racism and limits to transformation. Almost three decades post-1994, race and racism continue to affect many South Africans’ lives. The institutional cultures and environments of HWI’s are embedded in the historical legacies of apartheid and Whiteness, and this hinders transformation. Research has indicated that Black students experience alienation and perceive a lack of transformation at Higher Education Institutions (HEI’s) and especially HWI’s in South Africa. However, many of these institutions have indeed amended their old policies and have transformation agendas aimed at welcoming students of the historically excluded groups and meeting government transformation requirements. The discrepancy between research findings on black student experiences and the universities’ stance regarding the exclusion, marginalization and racism, requires critical exploration. Based on a thematic analysis of semi-structured interviews with nine Black students at Stellenbosch University, the thesis shows that Whiteness and racism continues to mark students’ lived experiences on campus and that transformation policies without changes that are meaningful from the vantage point of Black experiences, often fall prey to becoming an illusionary, tokenistic façade that further fuels feelings of alienation. Black students experience immense pressure to assimilate and acculturate, and they are fraught with perceptions of being negated. As such “becoming” what institutional culture embraces and assimilating into campus culture becomes a priority; however, this also means “unbecoming” that which Whiteness categorizes and negates as inferior, a contradiction that leads to identity paralysis. This research sought to afford Black students a platform and a voice to share their experiences and perceptions of the campus environment, to explore their feelings of being welcome or unwelcome at the university and their perception of what a transformed HWI would look like. Findings reveal that Black students do not feel fully welcome, and that they experience a sense of being tolerated and offered a space to study at the institution as form of tokenism. Across participants, there seems to be a common sentiment of fighting: to study at Stellenbosch University, for space and recognition, to graduate and to disprove Black inferiority stereotypes.
A behavioural asset pricing approach: Perspectives from the South African stock market
(Stellenbosch University, 2024-12) de Vries, Annalien; Erasmus, Pierre; Gorgens, Gina; Stellenbosch University. Faculty of Economic and Management Sciences. Dept. of Business Management.
The estimation of a company’s cost of equity has been the subject of extensive debate due to its subjective nature. Existing asset pricing models being employed to estimate the cost of equity (returns) assume investors have homogeneous beliefs and expectations pertaining to expected returns. There is, however, heterogeneity in investors’ expectations of returns. Due to this heterogeneity not being accounted for, the accuracy of existing asset pricing models is questioned. To improve its accuracy, sentiment stochastic processes can be incorporated into asset pricing models to account for the heterogeneity in the decision-making of multiple investors in the market, during different market conditions. Prior research in South Africa has concluded that investor sentiment should be considered an explanatory variable in asset pricing models; however, none of these studies have augmented existing asset pricing models such as the Carhart four-factor (CH4) model, with an investor sentiment variable. The primary objective of the current research was, therefore, to account for the human element in the South African stock market, by investigating the impact of investor sentiment on the cross-sectional variation of the cost of equity for securities listed on the Johannesburg Stock Exchange (JSE) for the period 2003 to 2019. To address this aim, the CH4-model was augmented with investor sentiment as an affective risk factor. One indirect measure (composite sentiment index) and three direct measures (survey and textual analysis-based measures) were empirically tested. By employing a judgement sampling technique, the final sample comprised of 321 securities that formed part of the FTSE/JSE All share index (ALSI) over the 17-year study period. Variations of regression analyses were employed for hypothesis testing. Ordinary least squares (OLS) time-series regressions revealed that a statistically significant relationship exists between returns and the direct measures of investor sentiment only. These results indicated that direct and indirect measures of investor sentiment contain unique information. A further finding was that the two direct proxies that resembled sentiment toward the economic and business conditions in South Africa, reported significant explanatory power for returns, of which the proxy measured by means of textual analysis was the most significant predictor. OLS regressions were also conducted for high and low sentiment periods, to assess the statistical significance of the CH4-model risk factors during different sentiment periods. The regressions uncovered contrasting results for only the momentum risk factor. During low sentiment periods, the relationship between the momentum factor and returns was negative and not significant, whilst high sentiment periods revealed a positive and statistically significant relationship. It was, thus, concluded that trading behaviour in the South African stock market, vary across high and low sentiment periods. This finding is in line with Lo’s (2004) adaptive market hypothesis. The Fama and Macbeth (FM) (1973) two-stage regression approach confirmed that investor sentiment does have a statistically significant impact on the cross-sectional variation of the cost of equity for JSE-listed securities. Similar to the OLS regressions, the two direct measures that reflect investors’ overall sentiment towards the country and the business climate within the country, were significant predictors of returns. Furthermore, contrasting relationships were reported between the use of constant and rolling betas. The difference in the direction of the cross-sectional association, confirms the argument that the association between sentiment and returns can be either positive or negative, depending on conditions within the market and economy. The current research makes an important theoretical contribution to asset pricing research and behavioural finance research in South Africa, by providing a theoretical justification for why investor sentiment should be incorporated into asset pricing models. A methodological contribution was also made by constructing a composite investor sentiment index for the South African stock market, and by investigating and comparing several diverse measures of investor sentiment. Educators, investors, financial managers and policymakers are encouraged to incorporate investor sentiment in their curriculums, investment strategies, cost of equity estimations and monetary policies, to reap the potential benefits from emphasising the individuals, whose collective behaviour ultimately drives markets.

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