4. Electronic Theses and Dissertations (ETDs) - Faculties submissions
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Item Predicting in-hospital mortality in heart failure patients using machine learning(University of the Witwatersrand, Johannesburg, 2023-05) Mpanya, Dineo; Ntsinjana, HopewellThe age of onset and causes of heart failure differ between high-income and low-and-middle-income countries (LMIC). Heart failure patients in LMIC also experience a higher mortality rate. Innovative ways that can risk stratify heart failure patients in this region are needed. The aim of this study was to demonstrate the utility of machine learning in predicting all-cause mortality in heart failure patients hospitalised in a tertiary academic centre. Six supervised machine learning algorithms were trained to predict in-hospital all-cause mortality using data from 500 consecutive heart failure patients with a left ventricular ejection fraction (LVEF) less than 50%. The mean age was 55.2 ± 16.8 years. There were 271 (54.2%) males, and the mean LVEF was 29 ± 9.2%. The median duration of hospitalisation was 7 days (interquartile range: 4–11), and it did not differ between patients discharged alive and those who died. After a prediction window of 4 years (interquartile range: 2–6), 84 (16.8%) patients died before discharge from the hospital. The area under the receiver operating characteristic curve was 0.82, 0.78, 0.77, 0.76, 0.75, and 0.62 for random forest, logistic regression, support vector machines (SVM), extreme gradient boosting, multilayer perceptron (MLP), and decision trees, and the accuracy during the test phase was 88, 87, 86, 82, 78, and 76% for random forest, MLP, SVM, extreme gradient boosting, decision trees, and logistic regression. The support vector machines were the best performing algorithm, and furosemide, beta-blockers, spironolactone, early diastolic murmur, and a parasternal heave had a positive coefficient with the target feature, whereas coronary artery disease, potassium, oedema grade, ischaemic cardiomyopathy, and right bundle branch block on electrocardiogram had negative coefficients. Despite a small sample size, supervised machine learning algorithms successfully predicted all-cause mortality with modest accuracy. The SVM model will be externally validated using data from multiple cardiology centres in South Africa before developing a uniquely African risk prediction tool that can potentially transform heart failure management through precision medicine.Item The potential of zingerone to protect against alcohol-induced liver disease(University of the Witwatersrand, Johannesburg, 2023-05) Asiedu, Bernice; Chivandi, Eliton; Nyakudya, Trevor; Lembede, BusisaniAlcohol can cross the placental blood-barrier and can also be secreted into breast milk. This can affect developing foetuses and/or nursing neonates negatively, thus impacting on metabolic health in early or later life. Zingerone (ZO) has anti-oxidant, anti-diabetic, anti-inflammatory, hypolipidaemic and hepato-protective properties. I hypothesised that neonatal oral administration of ZO could programme for protection against alcohol-induced metabolic derangements in suckling Sprague-Dawley (SD) rat pups mimicking human neonates that indirectly consume alcohol through their mother’s breast milk. The first experiment evaluated ZO’s potential to protect suckling rat pups against alcohol-induced metabolic derangements. Seventy 10-day old SD rat pups (males = 35; females = 35) were randomly assigned to four groups and administered treatments daily from postnatal (PND) 12-21: group 1-nutritive milk (NM), group 2-1 g/kg body mass ethanol (Eth), group 3-40 mg/kg body mass ZO and group 4 - NM+Eth+ZO. Terminal body mass, blood glucose concentration, lipid profile and hepatic antioxidant status were determined. Zingerone and ethanol had no effect on pups’ growth performance, blood glucose, total cholesterol, HDL- and LDL-cholesterol and hepatic thiobarbituric acid (TBARs), superoxide dismutase and catalase concentrations (p > 0.05). Ethanol decreased plasma triglyceride concentration in female rat pups (p = 0.04) but increased hepatic cytochrome P450E21 (CYP2E1) and decreased total glutathione (tGSH) concentration in male rat pups (p < 0.05). Zingerone increased tGSH in male rat pups (p = 0.003). A combination of ZO and ethanol increased (p = 0.047) hepatic CP2E1 concentration in male rat pups compared to control but had no effect (p = 0.717) on tGSH concentration. Neonatal orally administered ethanol induced hepatic oxidative stress which ZO, administered during the suckling period, failed to protect against. In experiment II, 123 SD rat pups (males = 60; females = 63) were administered the same neonatal interventions as in experiment I but from PDN22 they were grown to adolescence (PND45) with ad libitum access to normal rat chow and tap water. From PND 46-100, rats from each of the four neonatal groups were divided into two subgroups: subgroup I had tap water and subgroup II had ethanol solution as drinking fluids, for eight weeks. Body mass, feed, fluid and caloric intake were measured. Blood glucose concentration, plasma alanine transaminase and aspartate transaminase (ALT and AST) activities, adiponectin (ADP), leptin (LEP) and insulin (INS), tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and cytochrome P4502E1 (CYP2E1) concentrations were measured. HOMA-IR was computed. Visceral fat mass, hepatic fat content and histomorphometry were assessed. Hepatic TBARs and mRNA expressions of peroxisome proliferator activator receptor-alpha (PPAR-α), sterol regulatory element binding protein 1c (SREBP1c), nuclear factor kappa beta (NF-Kβ) and TNF-α were measured. Ethanol consumption in adulthood decreased feed and fluid intake but increased calorie intake and plasma CYP2E1 concentration (p < 0.05 vs control). It decreased blood glucose concentration of male rats (p = 0.026). A late single- and a double-alcohol hit had no effect on body and visceral fat mass of the rats (p > 0.05). Neonatal orally administered zingerone and ethanol and consumption of ethanol in adulthood had no effect on body mass, plasma lipid profile, adiponectin, leptin and insulin concentrations, HOMA-IR, AST and ALT activities, IL-6, TNF-α and hepatic TBARS and mRNA expression of NF-KB and TNF-α (p >0.05). A late single hit with ethanol increased hepatic fat content of male rats only (p = 0.014). A double and or late single ethanol hit increased liver fat content in female rats (p < 0.05). Both a late single and double ethanol hit downregulated PPAR-α but upregulated SREBP1c expression in male and female rats (p < 0.05) and it caused the development of large droplet macrosteatosis. A combination of neonatal orally administered ZO and a late single ethanol hit decreased visceral fat mass of female rats (p = 0.045 vs control) but it did not affect the blood glucose concentration of male rats (p > 0.05). Neonatal orally administered ZO with either a late single- or a double-ethanol hit caused hepatic macrosteatosis, but it had no effect on mRNA expression of PPAR-α of the rats (p > 0.05). However, neonatal orally administered ZO in combination with a late single ethanol hit did not affect SREBP1c expression of the rats but a combination of neonatal orally administered ZO with a double ethanol hit increased SREBP1c expression of female rats (p = 0.005). The responses of the rats to interventions showed sexual dimorphism: ethanol consumption in adulthood decreased blood glucose concentration of male rats only and an early single ethanol hit caused microsteatosis only in female rats. Zingerone protected male rats against ethanol-induced hepatic fat accumulation. It attenuated the ethanol-induced upregulation of hepatic SREPB1c expression in males but not in females. Ethanol (late single and/or double hit) downregulated the hepatic PPAR-α expression in the rats which was mitigated by ZO. Neonatal orally administered ZO attenuated the late single- and double-hit ethanol-induced macrosteatosis in the rats. Thus, neonatal orally administered ZO can potentially be used as a prophylactic agent against ethanol-induced hepatic lipid accumulation in males and steatosis in both males and females.Item The Experiences of Black Female Postgraduate Students With Mental Health During The Covid-19 Pandemic, 2019-2021, The Case of Witwatersrand University(University of the Witwatersrand, Johannesburg, 2024) Mashiane, Sphiwe; Bala, SamkeloThe COVID-19 global pandemic has compelled institutions of higher education to transition to emergency remote learning, leading many postgraduate students, both nationally and internationally, to begin their studies online. Research has shown the need for universities to support the transition from undergraduate to postgraduate as this is a major transition into academia. Research has also revealed that the struggle with mental health has increased with this transition and additionally with the COVID-19 pandemic, however, there is a lack of research investigating the experiences of Black females in the academic space and their experiences with mental health. Thus, this study aims to understand the experiences of Black female postgraduate students with mental health during the spread of COVID-19, 2019-2021. The research approach used for this study was the qualitative approach as it was the most appropriate in seeking to understand the experiences of a unique group such as a Black female postgraduate. A case study design was employed, and the experiences shared were explored through the lens of the intersectionality theory and the research was grounded by the interpretivist paradigm. The sample was drawn from the population of students from Witwatersrand University and the sample consisted of eight (8) participants. The method of data collection was computer-mediated interviews which were interpreted using a five-phase thematic analysis. The participants' responses revealed that although all eight participants experienced challenges with their mental health sharing symptoms associated with anxiety, stress, depression, and loneliness, only two participants used the psychosocial services offered by the university. The reasons for not seeking help from the university psychosocial services included fear of the unknown, services feeling unreachable, stigma and fear of not being assisted immediately. The most shared reason for not seeking help however was participants not perceiving the need to seek help. Participants, therefore, opted for coping mechanisms such as sleeping, partying, and using substances and most participants turned to their spirituality. The study, therefore, made recommendations for campus psychosocial services to employ more mental health practitioners such that there is education about mental health and the services offered.Item Neurocognitive Rehabilitation for an Adolescent HIV Population: The Case of Sustained Attention(University of the Witwatersrand, Johannesburg, 2024) Zondo, SizweThe Human Immunodeficiency Virus (HIV) continues to be a significant disease burden. In terms of neurocognitive health, HIV crosses the blood-brain barrier, resulting in neuronal dysregulation and compromised neurocognition. Of further import, antiretroviral drugs are indicated to have limited permeability in the central nervous system and do not reverse compromised neurocognition, sequent HIV neuroinvasion. The objectives of the study were to investigate the efficacy of HIV cognitive rehabilitation therapy (HIV-CRT) in adolescent HIV. The first aim was to investigate the evidence for the cognitive rehabilitation of HIV in adolescent and geriatric samples, sequent neuroHIV. This investigation resulted in the publication of a meta-analysis detailing the efficacy of attention remediation in neuroHIV. The second aim was to examine the efficacy of fNIRS neuroimaging in measuring hemodynamic responses in the prefrontal cortex in adolescents neuroHIV. This investigation resulted in the publication of an article detailing the efficacy of fNIRS in detailing changes in oxygenated haemoglobin in adolescents living with neuroHIV. The third aim was to pair fNIRS optical neuroimaging with behavioural data to investigate changes associated with brain training at a cortical and behavioural level. The execution of the above aim resulted in the publication of an article detailing the procedures and methods to achieve the enquiry. The fourth article, under review, details findings related to neural efficiency and attention training. The final manuscript, under preparation, details functional connectivity outcomes related to attention training. To enable the analysis of the published articles, an initial cohort of 42 adolescents (mean age = 17.28) living with HIV participated in the study. Following attrition, the sample was reduced to 26 participants. Thirteen participants were assigned to the treatment group (n = 13; mean age = 16; SD = 1.2), which received cognitive rehabilitation to remediate attention. Thirteen children acted as controls (mean age = 17; SD = 1.3). Pre- and post-intervention data were analysed using behavioural and optical imaging data. 5 Findings indicated that HIV-CRT (attention) is associated with decreased oxygenated haemoglobin (HbO) and increased functional connectivity in the Central Executive Network (CEN). Contrary to expectation, HIV-CRT was associated with minimal behavioural gains, as indicated by neuropsychological assessments. Taken together, findings seem to suggest that in adolescent neuroHIV, customised HIV-CRT promotes cortical efficiency. However, brain training does not translate to immediate behavioural improvements at post-assessment. Summarily, findings suggest that cortical plasticity may precede near-and-far cognitive transfer gain in adolescents neuroHIV.Item Career adaptability, occupational identity, and psychologica well-being after a career change during the covid-19 pandemic(University of the Witwatersrand, Johannesburg, 2024) Kutu, Siyamthanda; Donald, FionaOBJECTIVE: This study aims to explore the relationship between career adaptability, occupational identity, and Psychological Well-being at Work in South African employees who experienced career change during the COVID-19 pandemic. The study is framed within the Career Construction Theory where the pandemic is contextualised as a career shock. METHODS: Employing a quantitative approach, this study adopts a correlational, non-experimental, cross-sectional research design. Purposive sampling, including criterion-based and snowball sampling techniques, was utilized to recruit participants. The sample comprised 62 South African employees who experienced career changes between 2020 and 2022 due to the pandemic's impact on the labour market. Data w as collected through structured online questionnaires, incorporating validated scales. Ethical considerations were addressed, ensuring informed consent, confidentiality, and minimal harm to participants. RESULTS: Regression analysis revealed significant positive relationships between career adaptability, occupational identity, and Psychological Well-being at Work. Specifically, both career adaptability and occupational identity emerged as strong predictors of Psychological Well-being at Work among the participants. Descriptive statistics provided insights into the sample characteristics, indicating a diverse range of career change experiences during the pandemic. The study under scores the importance of fostering adaptability and building a robust occupational identity to enhance employees' psychological well-being amidst career transitions, particularly in times of crisis like COVID-19.Item The Exploration of the experiences and perceptions of service providers on the implementation of the Amendments to the Criminal Law (Sexual Offenses and Related Matters) Amendment Act 13 of 2021: The case of statutory rape in Johannesburg, Gauteng(University of the Witwatersrand, Johannesburg, 2024) Doodhnath, Sirishka; Nkala-Dlamini, BusisiweThis study aims to explore service providers’ perceptions and experiences regarding the implementation of the Criminal Law (Sexual Offences and Related Matters) Amendment Act 13 of 2021 in South Africa. The study examined the regulations concerning the age of consent for sexual activity involving minors, which are considered essential in addressing statutory rape. Using a qualitative research approach and exploratory study design, the study sought to gain an in-depth understanding of service providers on the effectiveness of the Act in addressing statutory rape and related issues. 12 service providers who have worked on the Amended Act were recruited and sampled for the study with the assistance of the Department of Community Safety. The department provided the researcher with a list of multi-disciplinary team professionals involved in the Victim Empowerment program. The study employed semi- structured interviews using interview guides to collect data from all service providers involved in the implementation of the Act. Thematic analysis was used to analyse the data and to identify recurring themes. The study findings offer insights that can assist policymakers in addressing the challenges and gaps in the implementation of the Act, with the goal of protecting minors and combating statutory rape in South Africa.Item Exploring Stigmas and Emotions of Transgender People Using Rasa Theory and Rasaboxes in Drama Therapy(University of the Witwatersrand, Johannesburg, 2024) Keseni, Siphokuhle Cleopathra; Henriques, LeilaThe goal of this study is to explore the emotional experiences of people who identify as transgender. Through Performance Ethnography, I hope to create awareness about how transgender individuals feel and how their experiences are influenced by the stigmas surrounding them. Performance Ethnography is a qualitative data collection method that explores the various facets of performance. It involves combining multiple ethnographic techniques and theoretical frameworks from performance studies (Finesurrey, 2019). I will use semi-structured qualitative interviews, audio recordings, journal writing, observation and performance to collect data. In this performance, I will use the collected data to create the performance. I will be using rasa boxes to move from one emotion to another. The data will be created by Rasa in real-time, and the audience will be able to hear and inspect it as it is presented. My research participants will be transgender individuals aged 20-35 years old.Item The perceptions of social workers on the implementation of the Occupation Specific Dispensation policy (OSD) within the Department of Social Development in the Johannesburg Region(University of the Witwatersrand, Johannesburg, 2020) Mathebula, Sipho Sol; Masinga, PoppyThe Occupation Specific Dispensation (0SD) policy was introduced in the public service for social workers in 2009 as a strategy to recruit and retain social workers with the introduction of new salary scales, career pathing, pay and grade progression and recognition of appropriate experience. The perceptions of social workers on the implementation of the OSD policy have not been established and this lack of knowledge leaves a gap in understanding the perceived impact this policy has had on social workers. The aim of the study was to explore the perceptions of social workers on the implementation of the Occupation Specific Dispensation policy within the Department of Social Development in the Johannesburg Region. Since implementation of the policy, there has been research studies conducted on the outcomes of the OSD policy within the public health sector yet no studies have been conduct that focus on the challenges encountered by social workers in the implementation of the policy. The study utilised the qualitative research approach which was exploratory and descriptive in nature. The collective case study design was adopted. A sample of ten social workers and three key informants were selected using purposive sampling. Data was collected using semi-structured interviews and analysed using thematic content analysis. The key finding was that the OSD policy was not effective in recruitment since it is rigid and inflexible. Another concern raised was the long period it took to move from one occupational level to the next resulting in a demotivated and demoralised workforce. The study also found that there was management bias in the implementation of the performance management and development system. The study contributes to our understanding of the perceptions about the unintended consequences of the OSD policy and how these are perceived to have impacted negatively on the recruitment and retention of social workers.Item Azibuye Emasisweni: Exploring Everyday Notions of Zulu Nationalism Through the Women in the Hostels of Alexandra Township(University of the Witwatersrand, Johannesburg, 2024) Makhathini, Sinqobile; Mngomezulu, NosiphoThis thesis explores the lives of four women who ethnically identify as Zulu within the hostels of Alexandra. Hostels, which refer to the housing compounds that were established as ethnically segregated and gender-distinguished spheres for the colonial migrant labour system, have become an essential axis for Zulu nationalist revival away from Kwa-Zulu Natal. Through participant observation and semi-structured interviews, I examine how Mam’Dlamini (57 years), the Nduna of Madala hostel and three hostel residents: Nokukhanya (23years), Mam’Nzama (55 years), Nokwazi (21 years), engage and shape forms of Zulu nationalism within their everyday life. I further engaged in autoethnography, whereby I positioned myself as the fifth participant, undertaking self-reflexivity about my identification as a Zulu woman. My work is invested in ukuzwa ngenkaba, listening with the umbilical cord, which is to say, centring African epistemologies in the ways we research (Mkhize 2023). In this way, I think through Fox and Miller-Idriss’ (2008) four modalities of everyday nationhood (talking, choosing, consuming and performing the nation) within Zulu conceptual frames. In my research, I found that in “talking the nation'' women used ulimi and ukuncelisa both literally and figuratively to signal membership and centre the role of mothers in shaping Zulu subjectivity. The framing of choices as national is understood by participants as more than individual articulations of personal agency but importantly incorporates inherited traditions. Ordinary people are not simply uncritical consumers of the nation; they are simultaneously its creative producers through everyday acts of consumption (Fox et al 2008, 505). My research shows how rituals become fertile sites for enacting Zulu personhood through specific forms of consumption and production. Performing the nation was evidenced through the women’s embodied expressions of inhlonipho. These themes have allowed for the understanding of how women do not remain hidden within notions of co-constituting but rather preserve this order from and beyond their matriarchal hold of the hostel.Item People’s Dignity is at stake: The Ambulance Availability Crisis in Lusikisiki, Ingquza Hill Local Municipality(University of the Witwatersrand, Johannesburg, 2024) Bolitina, SinovuyoAccess to healthcare is and remains a challenge globally. In South Africa, the limited ambulance availability crisis is an example of this. The people affected the most rely on public healthcare in remote and rural areas, such as the small town of Lusikisiki in the Eastern Cape Province. This study sought to investigate the research question, “How does the limited ambulance availability impact access to public healthcare for the people of Lusikisiki in the Ingquza Hill Local Municipality?”. I adopted a qualitative research approach and interviewed twenty participants identified through purposive and snowball sampling techniques. Limited ambulance availability inhibits the people of Lusikisiki from accessing healthcare. This crisis exists and impacts clusters of communities already facing socioeconomic, political, and geographical issues. These factors are at play and impact people’s day-to-day lives. Recommendations entail implementing more strategies and policies, looking at a more holistic approach, and examining this crisis from a social and health context perspective to overcome healthcare access barriers; thereby ensuring access and the health and well-being of everyone.