39624 research outputs found
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Examining the impact of delayed payments on SMME’s by Gauteng Provincial government
No full textA research report submitted in fulfillment of the requirements for the Master of Business Management, in the Faculty of Commerce Law and Management, Wits Business School, University of the Witwatersrand, Johannesburg, 2025The study conducted by (S. Y. Paul & Boden, 2011) uncovered that late payments by governments and large corporations significantly undermine their sustainability. In the United Kingdom, delayed payments contribute to the insolvency of approximately 50,000 small businesses annually, with an average loss of £22,000 per business due to late payments. Similarly, in Australia, over 20% of SMME’s are at risk of insolvency under new payment laws, exacerbating cash flow challenges. Small, Medium, and Micro Enterprises (SMMEs) play an important role in the economy’s growth and promote grassroots entrepreneurial activities in South Africa. However, SMMEs encounter myriad of challenges which affect their effectiveness. Such challenges include cash flow, poor financial management, and late payments. This study aims to examine the impact of late payments by the Gauteng Provincial Government on SMMEs. This mixed methods study recruited 150 participants, representing SMME’s in Gauteng. Data were collected using qualitative and quantitative instruments. The study employed statistical analysis to investigate the extent of payment delays experienced by the participants. The study examined the effects on their financial health, operational capacities, and viability. The study’s findings have significant implications for both policymakers in formulating targeted strategies, including enhanced invoice tracking systems, stronger enforcement of payment deadlines, and the establishment of assistance mechanisms, such as bridging finance facilities, for impacted SMMEs. and business owners to improve the effectiveness of SMMEs.MM202
Immunomodulatory effects of vitamin D on TLR7 and TLR8 signalling in monocytes and monocyte-derived macrophages
No full textA dissertation submitted in fulfilment of the requirements for the degree Master of Science, to the Faculty of Science, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, 2025Monocytes and macrophages are crucial innate immune cells known for their role in antiviral signalling. They respond to viruses via intracellular membrane receptors such as toll-like receptor 7 (TLR7) and toll-like receptor 8 (TLR8). When these receptors are activated, inflammatory cytokines and chemokines are produced downstream which play an important role in the inhibition of viral replication. However, the excessive production of these proinflammatory mediators results in chronic inflammation which can cause multi-organ failure and has been linked to various autoimmune disorders. Thus, there is a need to regulate these pathways. 1,25-dihydroxyvitamin D3 (1,25D3) is a recognised immune modulator, widely accepted as promoting an anti-inflammatory state. 1,25D3 is thought to reduce the production of proinflammatory mediators, thereby playing a role in the maintenance of immune homeostasis. As such, the aim of this research project was to investigate the effect of 1,25D3 on TLR7 and TLR8 expression and function in monocytes and monocyte-derived macrophages (MDMs). This was done by assessing the expression of TLR7 and TLR8 in Tohoku Hospital Pediatrics-1 cells (THP-1) and THP-1 derived macrophages, and the effect of 1,25D3 thereon using RNA-sequencing. Furthermore, interleukin-1 beta (IL1β), chemokine (C-C motif) ligand 2 (CCL2), C-X-C motif chemokine ligand 10 (CXCL10), and Interleukin-10 (IL10) expression was measured using RT-qPCR in monocytes and MDMs cultured in the absence or presence of 1,25D3. Thereafter, the downstream functional effects were investigated by activating the TLR7 and TLR8 signalling pathways using vesatolimod and motolimod, respectively, in monocytes and MDMs cultured in the absence or presence of 1,25D3 and measuring the expression of IL1β, CCL2, CXCL10, and IL10. Lastly, to assess the effect of additional 1,25D3 supplementation, TLR7 and TLR8-stimulated monocytes and MDMs cultured in a 1,25D3 ‘sufficient’ vs 1,25D3 ‘insufficient’ environment were treated with additional 1,25D3, and the expression of IL1β, CCL2, CXCL10, and IL10 were measured using RT-qPCR. Results showed that the expression of TLR7 was decreased, while the expression of TLR8 was increased in both monocytes and MDMs cultured in the presence of 1,25D3. Additionally, the expression of IL1β, CCL2, and CXCL10 were decreased in the MDMs cultured in the presence of 1,25D3. Interestingly, the monocytes responded to TLR8 stimulation, but not TLR7 stimulation, while the MDMs responded to both TLR7 and TLR8 stimulation, regardless of the absence or presence of 1,25D3. The expression IL1β, CCL2, and CXCL10 appeared to be enhanced in monocytes cultured in the presence of 1,25D3, while only CCL2 and CXCL10 expression were enhanced in MDMs cultured in the presence of 1,25D3. However, this trend was not observed with IL1β expression, which was decreased in MDMs cultured in the presence of 1,25D3. Lastly, monocytes and MDMs cultured in a 1,25D3 ‘insufficient’ environment continued to respond to TLR7 and TLR8 stimulation upon additional 1,25D3 supplementation, but while monocytes and MDMs cultured in a 1,25D3 ‘sufficient’ environment continued to respond to TLR8 stimulation, they were no longer responsive to TLR7 stimulation upon additional 1,25D3 supplementation. Overall, these results highlight the role of 1,25D3 as an immunomodulator, with its ability to both enhance the production of proinflammatory mediators, while also modulating their production to prevent the risk of creating a hyperinflammatory environment. This research directly demonstrated the contrasting effects of 1,25D3 on TLR7 and TLR8 signalling which not many studies have highlighted. Additionally, this study aimed to highlight the benefits and importance of maintaining sufficient 1,25D3 levels.National Research Foundation (NRF)MMM202
Exploring South African entrepreneurs leveraging technology for innovation and growth
No full textA research report submitted in fulfillment of the requirements for the Master of Business Administration, in the Faculty of Commerce Law and Management, Wits Business School, University of the Witwatersrand, Johannesburg, 2025This qualitative study explores the drivers, challenges, and external enablers influencing how Soth African SMMEs adopt technologies such as cloud computing, artificial intelligence (AI), and mobile applications to support innovation and growth. Guided by the Resource-Based View (RBV) and Diffusion of Innovation (DOI) theory, the study investigates, what motivates technology adoption, what challenges are encountered, and how external factors such as support services and infrastructure influence the adoption process. Through thematic analysis of in-depth interviews, the study finds that while technology enhances efficiency and scalability, its uptake is often constrained by financial limitations, digital skills gaps, and limited institutional support. The study recommends targeted policy interventions, improved access to funding, and practical skills development to support SMMEs digital transformation.MM202
The burden of injuries associated with accidents involving passengers carried in open bed pickup trucks a review of 371 patients managed in a major trauma centre in South Africa
No full text“The Gothic Viscount” A critical reading of Italo Calvino’s Il visconte dimezzato through a gothic lens
No full textA research report submitted in partial fulfilment of the requirements for the degree of Master of Arts in Italian Studies, to the Faculty of Humanities, School of Literature, Language, and Media, University of the Witwatersrand, Johannesburg, 2025The aim of this research paper is to analyse and explore Italo Calvino’s Il visconte dimezzato from a Gothic literary perspective and to contextualise the novel within the realm of the Italian gothic. In doing so, this research expands on the increasing body of academic work which has begun to explore Italian literature through a gothic perspective, a field of research which has largely been neglected by Italian academia. Through a critical reading, the report shows that the novel can indeed be considered a work of gothic fiction, and furthermore that several key themes and topics of the novel, such as the cold war, are emphasised and enhanced through a gothic reading. Additionally, the report demonstrates that through the application of gothic themes and concepts, we are better able to understand Calvino’s social commentary and criticism of Italian society found within the novel, and further understand how social norms and structures are discussed and subversed through the use of gothic imagery and themes, such as the gothic monster, the gothic heroine, and the newly emerging concept of the ecogothic, specifically within the context of Italian society and culture. The report also highlights the growing importance of the gothic modality in the realm of Italian literature, and argues that the Italian gothic is a genre distinct from its northern european/english counterpart.MMM202
Optimising Visual Clarity using Clustering Techniques for Overcrowded Biplots
No full textA research report submitted in partial fulfilment of the requirements for the degree of Master of Science in Mathematical Statistics, to the Faculty of Science, University of the Witwatersrand, Johannesburg, 2025The increasing use of data in various industries has driven the need for effective data analysis and visualisation. Data visualisation is a key methodology for extracting insights from the data. One powerful visualisation technique based on dimensionality reduction methods is the biplot. Biplots are multivariate scatterplots that facilitate the visualisation of high-dimensional data by projecting it onto lower dimensional spaces, usually two or three dimensions. This reduction in dimensionality is achieved using techniques such as Principal Component Analysis (PCA) for continuous data. A biplot simultaneously represents both samples and variables within the same visualisation. However, biplots often face challenges when dealing with a very large number of variables in data. A key issue is the overcrowding of variables within the biplot, making it difficult to obtain meaningful insights. To address this issue, this study explores the integration of unsupervised learning techniques, specifically clustering into the biplot framework. Unsupervised learning refers to a type of machine learning approach in which the algorithm learns patterns and relationships in the data without prior knowledge of the expected output. Clustering, a fundamental unsupervised learning technique, involves grouping similar data points into clusters, enabling the identification of underlying structures and relationships. By applying clustering, specifically the k-means clustering algorithm, this study aims to cluster similar variables into distinct clusters within the biplot. Similar variables are determined by the proximity of their endpoints and the angles they form within the biplot. Ultimately, the refined biplot displays only a representative cluster of vectors, thus enhancing the clarity and interpretability.MMM202
Geochemical and geochronological analysis of post-impact hydrothermal alteration in the Morokweng impact structure, South Africa
No full textA research report submitted in partial fulfilment of the requirements for the degree of Master of Science, to the Faculty of Science, School of Geosciences, University of the Witwatersrand, Johannesburg, 2025This study investigates evidence of post-impact hydrothermal activity in the 369 m long M4 drillcore, located 18 km NNW of the centre of the 80 km-wide, 146 Ma, Morokweng Impact Structure (MIS), South Africa. The core intersects fractured, faulted, brecciated and cataclased Archaean granitoid gneisses and minor dolerites that are intruded by mm- to m-wide pseudotachylite and suevite dykes, for which a peak ring setting has been proposed. Petrographic evidence indicates that impact-related shock features and breccias are overprinted by a dominantly zeolite-smectite paragenesis that contains some evidence of high-temperature (>350 °C) minerals such as actinolite, clinopyroxene, andradite and titanite, as well as minor amounts of calcite and anhydrite. Biotite shows varying degrees of alteration to chlorite. Pyrite occurs as part of the post impact assemblage locally, but the dominant Fe-bearing phases are magnetite, haematite and iron hydroxides such as goethite. The impact-related structures and the post-impact hydrothermal veins are cut by younger, mostly subhorizontal, mm- to cm-wide, calcite veins in the upper parts of the core that contain minor amounts of zeolite. The calcite vein textures vary from blocky coarse grained to fibrous/stretched to elongate-blocky and blocky/fine-grained and cross-cutting relationships indicate multiple veining events. Smectite-illite K-Ar ages range from 105.80 ± 4.43 Ma (214.40 m) to 68.88 ± 48.87 Ma (121.8 m), 59.45 ± 7.74 Ma (216 m) and 57.41 ± 7.14 (119 m). The correlation of age with grain size suggests that these ages might reflect resetting of the original impact hydrothermal assemblages formed at 146 Ma, although new mineral growth during discrete post-impact hydrothermal events cannot be completely ruled out. Four calcite veins analyzed via LA-ICP-MS yielded U-Pb ages of 66.46 ± 0.74, 16 ± 47, 28.1 ± 1.1, and 13.95 ± 4.32 Ma. The broad agreement between the oldest U-Pb calcite age and three of the smectite-illite ages suggests a significant hydrothermal event close to the Cretaceous-Palaeogene boundary. Stable isotope analysis indicates that the older calcite veins record heavier ẟ18O and varying ẟ13C values ranging from 21.45 to 27.39 ‰ and -21.80 to -9.24 ‰, respectively, whereas the younger veins record lighter ẟ18O and varying ẟ13C values of 19.00 to 22.04 ‰ and -19.79 to -3.99 ‰, respectively. Negative ẟ 13CPDB values are consistent with a meteoric groundwater influence enriched in dissolved organic carbon; however, the combined ẟ 13CPDB–ẟ 18OSMOW values suggest connate waters that interacted with a marine carbonate source. The ẟ 13CPDB–ẟ 18OSMOW values and age values vary between samples. The temperature of crystallization of the vein carbonate is estimated between 8.5 to 140.7 and > 200℃, using the stable isotope thermometer. Rare earth element (REE) patterns in the calcite veins are also sample-specific and show little to no correlation with the REE patterns of the host rocks, suggesting derivation from an external source and little to no interaction between the fluids and the wallrocks. One sample exhibits a pattern enriched in light rare earth elements relative to middle and heavy rare earth elements, with a negative Ce, slightly positive Gd, and positive Y anomalies, suggestive of precipitation under oxidizing conditions. However, two samples show flat REE patterns with strong positive Eu and Y anomalies, indicative of oxygen-poor hydrothermal fluids, while the fourth sample shows a flat REE pattern with a positive Y anomaly. These patterns indicate different fluid sources and may imply temporal variation in fluid composition related to different veining events. In conclusion, the calcite veins in the upper parts of the M4 drillcore appear to represent polyphase fluid infiltration events unrelated to the Morokweng impact event, and most likely are associated with discrete events relating to the poorly understood Late Cretaceous to Cenozoic tectonic and exhumation/burial history of the region.National Manpower Development Secretariat (NMDS) bursaryResearch Office Carnegie BursaryGeoscience Provision AccountDSI-NRFMMM202
Inclusive education and the associated classroom challenges: The teachers’ perspective with a focus on ASD
No full textA research report submitted in partial fulfilment of the requirements for the degree of Master of Education in Educational Psychology to the Faculty of Humanities, School of Human and Community Development, University of the Witwatersrand, Johannesburg, 2026Inclusive education is implemented in South Africa through inclusive policies such as Education White Paper 6, as well as the Screening, Assessment, Identification and Support Policy, which were used to guide the aims and questions of this research, as well as defining its scope. Inclusive education encompasses the inclusion of learners with Autism Spectrum Disorder characteristics, which is widely misunderstood and unidentified or unaccommodated. The current research set out to underline challenges faced by teachers when including learners with Autism Spectrum Disorder characteristics in the classroom in order to highlight gaps in the education system that these learners may fall through. Online questionnaires were dispersed to gather both qualitative and quantitative data. The gathered data were analysed using Chi-squared tests to highlight trends, which was followed by a thematic analysis to underline arising themes. It was determined that challenges such as the disconnect between theoretical awareness and practical application in the classroom environment, gaps in training and minimal support, inconsistent support from school-based support teams, a lack of knowledge of Autism Spectrum Disorder, and a lack of access to special schools and a rigorous placement process were outlined as possible reasons for learners with Autism Spectrum Disorder characteristics falling through the gaps. Focus areas were identified that need to be addressed in order to minimise learners with Autism Spectrum Disorder characteristics falling through the gaps, thereby maximising the inclusion of these learners in the education system.MMM202
Hungarian-Murty Soft Decision Decoding Scheme for a MIMO-STBC-SPM Communication System
No full textA research report submitted in fulfillment of the requirements for the Master of Science, in the Faculty of Engineering and the Built Environment, School of Electrical and Information Engineering, University of the Witwatersrand, Johannesburg, 2025The integration of Multiple-Input-Multiple-Output (MIMO), Space-Time Block Coding (STBC), and Spatial Permutation Modulation (SPM) has led to signifi- cant advancements in spectral efficiency and system performance. However, the decoding process in such systems can be computationally demanding. To address this challenge, a soft-decision decoding algorithm based on the Hungarian-Murty algorithm is proposed. The study aims to evaluate the impact and effectiveness of the Hungarian-Murty algorithm on the system’s performance, particularly in terms of Bit Error Rate (BER). The proposed algorithm seeks to enhance decoding efficiency while main- taining reliable error correction performance. The research reviews various low- complexity decoding algorithms and methods used to assess Space-Time Block Code performance, which have guided the development of the proposed solution. The study employs a MIMO-STBC-SPM transceiver system utilizing Quadrature Amplitude Modulation (QAM) and permutation in low-complexity schemes. The BER performance of these schemes is simulated in a Rayleigh fading multi-path channel with additional additive white Gaussian noise to support the evaluation of the proposed soft-decision decoding algorithm. The Hungarian-Murty Algorithm, a combinatorial optimization algorithm, is used to solve assignment problems within MIMO systems with STBC-generalized spa- tial permutation modulation. This algorithm optimizes the signal-to-noise ratio (SNR) at the receiver by finding the optimal permutation matrix for data bit encoding. The soft-decision decoder iteratively ranks the costs of the input sig- nal matrix until the assignment produces a valid code word, thereby improving decoding efficiency and error correction. STBC-SM (Space-Time Block Code with Spatial Modulation) and STBC-SPM are discussed, highlighting their enhancements in error rate performance through the integration of STBC techniques and the use of permutation vectors. Spatial Per- mutation Modulation (SPM) and Generalized Spatial Modulation (GSM) are also explored, demonstrating their contributions to improving diversity and reducing error rates. The findings of this study are expected to provide valuable insights into the Hungarian-Murty algorithm’s effectiveness in reducing computational complexity iv while maintaining reliable performance in MIMO-STBC-SPM systems, thereby advancing the field of wireless communications. An analysis of complexity shows that the Hungarian Murty Algorithm (HMA) con- siderably lowers computational requirements. While traditional Maximum Like- lihood (ML) Hard Decision Decoding operates with a factorial time complexity of O(K! · Nt), the HMA reduces this to a more manageable O(K4 · Nt), where K is the size of the permutation vector, and Nt denotes the number of transmit antennas. This simplification makes the HMA particularly advantageous for large MIMO systems. Regarding BER performance, the HMA-based decoder shows significant improve- ments, especially in systems utilizing 16-QAM modulation. Simulation results in- dicate that at higher SNR, the HMA can achieve up to a 2 dB improvement in BER compared to traditional ML Hard Decision Decoding. In contrast, at lower SNRs, 4-QAM systems perform better due to their resilience to noise, while the higher- order 16-QAM system benefits more from the HMA at increased SNRs, leading to better data throughput and reduced errors. Additionally, systems equipped with multiple receiving antennas (Nr = 2) experience up to a 30% decrease in BER at critical SNR levels. The results from this research underscore the potential of the Hungarian-Murty Algorithm to improve both computational efficiency and error performance in MIMO-STBC-SPM systems. By effectively balancing complexity and perfor- mance, the HMA offers a promising solution for enhancing the reliability and efficiency of wireless communication systems, particularly in challenging or high- noise conditions.MM202