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Comparative Analysis of Discrimination and Calibration Accuracy of Discrete Survival, Random Forests, and Neural Networks in Health-Related Survival Prediction Models
No full textMSc in StatisticsDepartment of Mathematical and Computational SciencesPrediction models for survival analysis are commonly used in biomedical sciences
to understand the onset of certain diseases. Traditional statistical models have
been employed for the previous years, however, their limitations and inability to
handle big data sets has made a way for the introduction of machine learning
methods which gained recognition due to their ability to learn complex algorithms.
However, existing literature indicates that the predictive accuracy of machine
learning and statistical models for survival analysis varies significantly across
different data sets. This variability underscores the need for further research
utilizing data sets with diverse characteristics. Such research is essential to develop
generalizable insights into the conditions under which each method performs best.
In this research project, we compared the predictive performance of traditional
statistical method and machine learning algorithms in discrete survival analysis.
The machine learning methods include discrete-time survival trees, discrete-time
random survival forests, and discrete-time neural networks. The study uses
calibration (measured by the prediction error curves) to assess model fit and
discrimination (measured by the Concordance index and area under curve) to
evaluate predictive accuracy. These methods were applied to data sets: Breast
cancer, age at first alcohol intake and CRASH-2. The discrete-time neural network
had the best prediction performance as compared to the rest of the models for
survival of breast cancer. The discrete-time random forest with hellinger distance
had the overall prediction performance on the age at first alcohol intake. The
discrete-time survival model outperformed the rest of the models in predicting
survival of bleeding trauma patients from the CRASH-2 data
Use and management of energy resources from Water, Energy, and Food (WEF) nexus perspective: The case of Vhembe District Municipality (VDM), Limpopo Province
No full textMENVSCI in Hydrology and Water ResourcesDepartment of Earth SciencesWater, Energy, and Food (WEF) are necessity resources required by human beings for sustenance, social, and economic development. Energy is at the centre of the WEF nexus due to its dual role as a driver of economic activity and the largest contributor to global warming and climate change risks. In response, most countries following the 2015 Paris Agreement on climate action have adopted renewable energy (herein referred to as smart energy practices and innovations) policies to mitigate the adverse impacts of energy on climate change, as well as address health and environmental crises. Such measures and policies are also pursued to enhance energy security and economic prosperity. Though South Africa is one of the countries that has adopted an ambitious renewable energy policy, there is a paucity of information on factors influencing the adoption of renewable based energy resources and potential outcomes at the household level, where most of the envisioned policy objectives are expected to be pursued and realised. The current study was conducted in the Nzhelele and Luvuvhu River catchment areas in the Vhembe District Municipality (VDM) of Limpopo Province. A mixed methods approach was used to gather information on energy access and use at the household level through household questionnaires and triangulated through key informant interviews (KII) and Focus Group Discussions (FGDs). Economic analysis of existing energy practices and innovations was analysed using a Net Present Value (NPV) analysis, and environmental performance assessed through Partial Life Cycle Analysis (LCA). Analysis of data was done in Excel and IBMR SPSSR Statistics version 28 based on weight estimation and multinomial logistic regression approaches. Biomass and mains electricity are the main sources of energy, with energy stacking being a universal strategy observed in majority of households. Renewable energy sources such as solar energy are rarely used at the household level. Approximately 62% of the respondents cited lack of knowledge (inadequate access to information) on the smart energy technologies and their availability as the most significant limiting factor in their adoption. This was followed by poor reliability of smart energy technologies at about 53%, cost saving potential at about 45%, and availability of finance at about 48%. For those in agriculture, market access at about 21% and return on investment at about 19% is an important consideration in the choice of smart energy technologies. Ease of availability and cost of energy type at 35% and 39% respectively were the main factors likely to influence the choice of smart energy innovations. Cost of alternatives at about 13%, load shedding at about 14 %, and socio-economic lockins i.e., culture and past policies at about 12% of the respondents. Employment and to a greater extent, total household income status, emerge as the only factor that significantly (P< 0.005) influences the adoption of smart energy innovations. The use of biomass and LPG are significant predictors of reliability in existing energy innovation. Though renewable energy sources such as solar can reduce environmental footprints, the initial cost and intermittent supply due to weather constrain their adoption. The adverse impact of non-renewable resources such as biomass on health and environment are inherent through higher emission levels. The same applies to coal generated electricity. However, the fact that such sources are cheaper and easily available due to economic lockins also constrains the transition to cleaner energy sources at household level. In conclusion, WEF approach can inform sustainability transition and energy security with economic empowerment and awareness creation, including access to higher education and income earning opportunities being more likely to mediate the transition to smart energy at household level
Application of organic acid functionalized cellulose for batch and aqueous two-phase extraction of sulfonamides from different matrices
No full textMSC in ChemistryDepartment of ChemistryAntibiotics are among the most widely used drugs globally, with fluoroquinolones, macrolides and sulfonamides being commonly prescribed. Sulfonamides, which form the basis of several sulfa drugs, have significant applications in both medicinal and synthetic organic chemistry. While these substances are effective in their intended uses, their negative environmental impact raises serious concerns. Sulfonamides can have toxic effects on aquatic ecosystems, leading to the disruption of microbial communities, bioaccumulation in organisms and the development of antibiotic resistance. To mitigate these effects, cellulose and its functionalized derivatives were investigated for their ability to adsorb sulfonamides from real wastewater, milk and honey samples. To improve adsorption, cellulose was functionalized with oxalic and adipic acid. The resulting sorbents were then analyzed using FTIR, PXRD and SEM techniques. Based on FTIR analysis the optimal reaction time for cellulose functionalized with adipic acid and oxalic acid via hydrothermal treatment in an autoclave was 1 h at a temperature of 50℃. Furthermore, the FTIR data revealed the emergence of ester moieties from the esterification reaction of carboxyl groups in the organic acids and the hydroxyl groups on cellulose. Based on PXRD analysis for the adipic acid functionalized cellulose contained a hybrid of adipic acid and oxalic acid peaks, indicating functionalization of cellulose. Batch adsorption experiments were conducted using sulfonamide based analytical standards: sulfachloropyradazine and sulfabenzamide, to evaluate the adsorption capability of cellulose and its functionalized derivatives at varying temperature, time, and mass of sorbent. The multivariate based optimal conditions for the adsorption of sulfachloropyradazine and sulfabenzamide using cellulose was 25°C, 180 min and 5 mg and with extraction efficiency of 70 and 51%, respectively. The optimal conditions for adsorption of sulfachloropyradazine and sulfabenzamide using oxalic acid functionalized cellulose was 25°C, 30 min and 50 mg with extraction efficiency of 64 and 75%, respectively. Adsorption of sulfachloropyradazine and sulfabenzamide using adipic acid functionalized cellulose was 25°C, 30 min, and 5 mg with extraction efficiency of 70 and 51%, respectively. Although cellulose functionalized with adipic and oxalic acid showed some influence on the adsorption behavior of sulfachloropyridazine and sulfabenzamide, the adsorption of sulfachloropyridazine was slightly reduced from 70% with unmodified cellulose to 64% with the functionalized form. Functionalizing cellulose with adipic and oxalic acid adds carboxyl and hydroxyl groups, enhancing adsorption of sulfachloropyradazine and sulfabenzamide through stronger hydrogen bonding, electrostatic
interactions, and possibly π-π stacking, compared to cellulose. Overall, the functionalization of cellulose with these acids is a promising approach for enhancing the adsorption of sulfonamides which could be applied in wastewater treatment
Knowledge, attitudes and practices of caregivers towards measles and measles vaccine in a selected village in Vhembe District, Limpopo Province
No full textMaster of Public HealthDepartment of Public HealthDespite the widespread availability of an effective and free measles vaccine, the infection remains a global public health challenge. While barriers to childhood immunization have been extensively studied worldwide, including in South Africa, there is limited information regarding caregivers' specific knowledge, attitudes, and practices (KAP) concerning measles and its vaccination in the South African context. Given the ongoing measles outbreaks in 2022–2024, it is imperative to investigate whether caregivers know their children's vaccination status and the recommended timing for measles immunization. This study aimed to assess the KAP of caregivers toward measles and its vaccine in a selected village in Limpopo Province.
The research was conducted alongside a scoping review to synthesize existing global literature on measles and vaccination and to inform the study's direction. The review incorporated keywords related to the study variables and sourced data from peer-reviewed journals, grey literature, and government reports. Subsequently, the study adopted a quantitative, cross-sectional, non-experimental descriptive design to gather data from caregivers of children aged six months to twelve years residing in the Vhembe District, Limpopo Province. Data were collected using a structured questionnaire designed to measure relevant variables. A simple random sampling method was employed to select 377 eligible respondents. The Statistical Package for the Social Sciences (SPSS, version 29.0) was utilized to analyze the data, presenting findings through tables, frequencies, and percentages, with Pearson correlation analysis used to explore associations.
The scoping review identified themes indicating that caregivers possess adequate knowledge about measles; however, attitudes toward the measles vaccine varied, with the majority reporting positive rather than negative attitudes. Factors influencing caregivers' KAP included vaccine hesitancy, demographic characteristics such as the age and educational status of the caregiver, logistic constraints, the caregiver-physician relationship, and the impact of the COVID-19 pandemic. The quantitative analysis revealed that most caregivers demonstrated low (32.1%) to moderate (66.2%) knowledge levels, while only 6.8% exhibited high knowledge. Attitude scores indicated that most caregivers (89.3%) held positive attitudes toward measles and its vaccine. Practice scores highlighted that the majority (94.2%) demonstrated generally positive practices.
The study found low knowledge could be attributed to limited exposure to measles infections and infrequent discussions with healthcare providers. The study recommends implementing targeted interventions that extend beyond mass community immunization campaigns. These should focus on educating caregivers about identifying measles cases and reinforcing the significance of vaccination, despite the limited exposure to the disease, to sustain community herd immunity
Strategies to Improve Access to Healthcare Services for Refugees and Asylum Seekers in Gauteng Province, South Africa
No full textPhD (Public Health)Department of Public HealthIntroduction: South Africa currently hosts approximately 250,250 refugees and asylum seekers, the highest among the nine countries included in the UNHCR’s Multi-Country Office. The constitution of South Africa and the Refugee Act of South Africa grant refugee and asylum seekers the right to access healthcare services as South African citizens, despite the provisions in the legislation that grant refugees and asylum seekers similar rights as South African citizens in terms of access to health services, they still experience challenges in accessing these services in Gauteng Province.
Aim: This study aimed to develop strategies to improve refugees' and asylum seekers' access to health care services in Gauteng Province, South Africa.
Methods: The study was conducted in three phases. An exploratory sequential mixed methods design was employed in Phase 1 of the study, where the initial phase adopted a qualitative approach, and the subsequent phase adopted a quantitative approach. Phase 1 (a) of this study employed a qualitative approach in Gauteng Province among 16 conveniently sampled Health professionals and 20 purposively sampled refugees and asylum seekers. Unstructured interviews were used to collect data, which was analysed thematically. The results from Phase 1 (a) were then used to inform Phase 1 (b). Phase 1 (b) adopted a quantitative approach based on the findings from the initial qualitative approach to strengthen and ensure the generalisability of the qualitative phase to a broader population. Data was collected through structured self-administered questionnaires from n=353 health professionals and n=367 refugees and asylum seekers who were randomly sampled. Descriptive analysis was performed on the collected data. Ethical principles of informed consent, anonymity, privacy, confidentiality, and avoidance of harm were adhered to throughout the study.
Results: The results from health professionals, refugees, and asylum seekers were reported separately. Nine themes emerged during data analysis. Four themes emerged from data collected from refugees and asylum seekers: Turnaround time, Hospital charges, Treatment by the hospital staff, and Practice in the hospital. Five themes emerged from data collected from health professionals: Communication challenges, corrupt activities by asylum seekers and refugees, hospital charges, attitude of asylum seekers, refugees and staff, and patients’ health-seeking behavior
Phase 1 (c) focused on meta-inference and conceptualization. Where a conclusion was drawn based on the qualitative and quantitative data gathered. Phase 2 focused on developing strategies using analysis of Strengths, Weaknesses, Opportunities, and Threats and a Build, Overcome, Explore, and Minimize Model to guide the process. The developed strategies include the purpose, core values, and 17 strategic objectives with action plans. In Phase 3, the Delphi Technique was used to validate the developed strategies with 13 validators considered experts in healthcare, migration, and academics.
Conclusion: There is a need to eliminate the language barriers between health professionals, refugees, and asylum seekers to ensure optimal access to services. Continuous provision of education in the refugee community will improve their understanding of the South African health system. Cultural competency training is needed to ensure acceptability between health professionals, refugees, and asylum seekers. There should be a collaboration between the community structures and local and international organizations with the Department of Health to address the existing challenges
Comparative Assessment of Grid-Tied and Isolated PV/Hybrid Energy System for Grid-Connected Facilities: Case of Masia Development Centre and Vuwani Science Centre Energy Systems
No full textMSC in PhysicsDepartment of PhysicsThe study underscores the significance of a sustainable energy system for national progress, particularly highlighting the increasing adoption of solar photovoltaic (PV) in South Africa. Solar PV integration into the current power generation systems offers financial and ecological benefits, but determining the optimal configuration, especially in areas with an existing utility grid, is challenging. A walk-through energy audit was conducted at the Masia Community Development Centre and the Vuwani Science Centre to establish accurate energy demand profiles. Using the Hybrid Optimisation Model for Multiple Energy Resources (HOMER), the study analysed load
characteristics for two sites: the Masia Community Development Centre and the Vuwani Science Centre. Results show that grid-connected (GC) systems outperform off-grid (OG) systems in technical and economic terms, as evidenced by their lower net present cost (NPC) and levelized cost of energy (LCOE) values, alongside higher power output. However, GC systems’ reliance on grid electricity, often derived from non-renewable sources, increases greenhouse gas emissions. Among the evaluated configurations, the Photovoltaic-Grid-Converter (PV/Grid/Conv) architecture emerged as the most cost-effective, delivering low NPC, LCOE, and operating costs of R1,852,811.00, R1.63, and R20,878.56, respectively, for Masia, and R2,969,068.00, R1.07, and R83,039.74 for Vuwani. When scaled to Masia’s total facility demand, values reached R15,768,780.00 NPC, R1.90 LCOE, and R365,062.00 operating costs. Despite its efficiency, the PV/Grid/Conv system struggles with nighttime supply. It is vulnerable to load shedding, suggesting the advantage of incorporating PV/Battery/Grid/Converter (PV/Batt/Grid/Conv) systems for enhanced reliability in critical applications. The off-grid (OG) systems remain vital for remote locations where grid extension is impractical, enabling sustainable electrification, reduced fossil fuel dependence, and greater energy independence. This analysis offers valuable guidance for energy planners and system designers, balancing economic performance, environmental impact, and reliability in PV system deployment.National Research Foundation (NRF
Assessing challenges faced by teachers in promoting inclusive educatiin to learners living with autism spectrum disorder, a case study of Vhembe East District
No full textMED in Inclusive EducationDepartment of Educational StudiesInclusive education aims to provide equal educational opportunities for all learners, including those living with Autism Spectrum Disorder. However, teachers often encounter significant challenges in implementing inclusive strategies that cater to the diverse needs of learners with ASD. This qualitative study explores teachers' barriers and challenges in promoting inclusive education for learners with ASD, focusing on their experiences, perceptions, and support systems. Promoting inclusive education for learners with ASD poses significant challenges, such as inadequate training, limited resources, lack of institutional support, and difficulties in classroom management. This study aims to assess challenges faced by teachers in promoting inclusive education to learners living with Autism Spectrum Disorder. The Social Learning Theory underpins the study, which emphasizes the role of observation, imitation, and modelling in learning. This theoretical framework informed the use of the Interpretivism paradigm, where qualitative methods such as interviews and observations were used to understand social phenomena as they prioritise the subjective experiences and meanings attributed by individuals. A nonprobability purposive sampling method was used to purposefully choose participants. Face-to-face interviews and focus group interviews were used as data collection techniques, and interview schedules were used as instruments. Data was analysed thematically. The findings revealed the need for targeted professional development, enhanced collaboration among teachers and specialists, and policy reforms to create a more supportive learning environment. The study recommended that there should be collaboration among stakeholders tailored to support teachers implementing inclusive education where such effective interventions can improve inclusive practices for learners living with ASD.Fundi and Limpopo Department of Educatio
Exploring the impact of COVID-19 curriculum recovery plan on English First-Additional language academic outcomes
No full textMED in Curriculum StudiesDepartment of Professional and Curriculum StudiesThe COVID-19 pandemic significantly disrupted teaching and learning, particularly in remote areas where lockdowns halted educational activities entirely. In response, the Department of Basic Education (DBE) developed the COVID-19 Curriculum Recovery Plan (CRP) to address untaught curriculum segments when schools reopened. This study assesses the impact of the CRP on English First Additional Language (EFAL) academic outcomes in the Vhembe District, Limpopo Province. Guided by Vygotsky’s social constructivist theory and an interpretivist paradigm, the research employed a phenomenological qualitative design. Data were collected through semi-structured interviews and focus group discussions involving 20 participants (educators, learners, and departmental heads) from four secondary schools in the Nzhelele Central Circuit. Thematic analysis revealed key challenges, including limited technology access, pedagogical adaptation difficulties, and gaps in curriculum delivery and support systems. Despite these barriers, the study identified positive outcomes in EFAL learners’ academic performance. The findings underscore the need for targeted interventions to enhance resilience in educational systems during crises. Recommendations include equipping schools with digital devices and internet access, alongside implementing continuous professional development programs for educators in remote teaching strategies, digital literacy, and innovative assessment methods. This study contributes actionable insights for stakeholders to mitigate the impact of future disruptions on EFAL outcomes
Asian Tigers Model as a strategy to achieve a developmental state in South Africa: a case of Thulamela Local Municipality
No full textThis study sought to evaluate the Asian Tigers Model as a strategy to achieve a developmental state in South Africa, with specific reference to Thulamela Local Municipality. The term "Asian Tigers" refers to East Asian countries such as South Korea, Taiwan, China, and Singapore, which achieved rapid economic growth and industrialization from the 1960s onwards. These nations implemented key elements of the Asian Tigers Model, including export-oriented industrialization, strong government intervention, investment in education and technology, and strategic trade policies. By examining the historical context and unique challenges facing South Africa, this study aimed to evaluate the applicability of the Asian Tigers Model to South Africa’s development trajectory. The analysis considered the potential benefits, challenges, and adaptations necessary for successful implementation, highlighting lessons learned and policy implications for fostering sustainable economic development in South Africa. In this study, the researcher employed a mixed research methodology, utilizing both qualitative and quantitative approaches. The motive behind using the mixed method was to enhance validity by providing deeper understanding through qualitative insights and broader coverage via quantitative data, resulting in more comprehensive and reliable conclusions. To achieve the study's objectives, non-probability sampling and its sub-type, purposive sampling, were used by the researcher to select samples. For data collection, two methods were employed: a structured questionnaire and interviews. The data collected through the structured questionnaire were analysed and presented in graphical tabular form, frequencies, and percentages, while the data collected via interviews were analysed and presented in a narrative form. This study aimed to offer a nuanced understanding of how the Asian Tigers Model can be adapted and applied to promote sustainable economic development in South Africa, with a focus on Thulamela Local Municipalit
Factors contributing to work-related fatigue among hospital nurses in Vhembe District, Limpopo, South Africa
No full textMPHDepartment of Public HealthWork-related fatigue among hospital nurses is a significant issue that affects both physical
and mental health, leading to mistakes that negatively impact patient care. The study's
goal was to identify and describe factors that contribute to work-related fatigue among
hospital nurses. This study used a qualitative approach, including exploratory, descriptive,
and contextual designs. The study population consisted of Hospital nurses from the
Vhembe district. Non-probability, purposive sampling used to select participants. The
study was conducted through an in-depth interview. The audiotape used to gather data
and data was transcribed verbatim for data analysis purposes. Credibility, conformability,
and dependability are examples of measures used to assure trustworthiness. Ethical
considerations were met.
The study findings revealed that factors that contributes to work related fatigue are heavy
workloads, consumption of caffeine, depressive experience, conflict with other staff
members, age, work-life imbalance, lack of breaks and rest, shortage of nurses, shift and
off duties, lack of resources, lack of social support, long work hours and lack of
appreciation of nurses towards contribution to nursing .Based on the study results,
recommendations were given