4. Electronic Theses and Dissertations (ETDs) - Faculties submissions
Permanent URI for this communityhttps://hdl.handle.net/10539/37773
Browse
318 results
Search Results
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 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 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 role of social media in career discovery, aspirations, and choice of South African university students: A Social Cognitive Perspective(University of the Witwatersrand, Johannesburg, 2024) Cronje, Sherrilee; Mlilo, SifisoThe aim of this study was to explore the role of social media in shaping the career discovery, aspirations, and choices of South African university students. This was explored through three key research questions around how South African university students perceive the influence of social media in the discovery and exploration of career options, how they perceive the influence of social media in the formations of their career aspirations, and how they perceive the influence of social media on their career decisions. A cross-sectional, qualitative, interpretivist research design was employed whereby data was gathered through non-probability convenience sampling through volunteers and snowball/chain sampling methods as well as a purposive strategy. Interviews were conducted on the sample, and these were then analysed through a thematic analysis methodology in order to explore the experiences of the participants. The sample consisted of 14 individuals between the ages of 22-27 who were studying in South Africa through a tertiary educational institution. The study utilized Social Cognitive Career Theory (SCCT) as a theoretical framework to understand the impact of social media on the behaviour and career development of South African students. SCCT proved highly beneficial in explaining the role of social media in shaping career interests and facilitating career exploration. While social media played a significant role in exposing students to various career options and influencing their perceptions, it was not perceived as the primary determinant of career choices. Rather, personal interests, passions, and other factors played a more significant role. Nevertheless, social media did have an indirect influence on career decisions by providing information and shaping perceptions. The study's findings align with previous research but also offer nuanced insights, contributing to the understanding of social media's role in the career journey. This research fills a gap in South African literature and lays the groundwork for future studies in this area.Item Development of an interprofessional education and collaborative practice curriculum for health science students at Sefako Makgatho Health Sciences University(University of the Witwatersrand, Johannesburg, 2023-09) Pitout, Susara Johanna Susanna; Barnard-Ashton, Paula; Adams, Fasloen; du Toit, Sanetta Henrietta JohannaA South African university required a contextually relevant, Interprofessional Education and Collaborative Practice (IPECP) curriculum. The study aimed to develop and validate an IPECP curriculum for health sciences students at Sefako Makgatho Health Sciences University (SMU). Planning the IPECP curriculum necessitated both a robust theoretical foundation and pragmatic problem-solving and comprised three phases. Phase I, the situational analysis included a scoping review of global peer-reviewed literature, focus groups with students and lecturers, and a university-wide needs survey. Brookfield’s lenses of critical reflection and reflexivity condensed results of the situational analysis into factors guiding curriculum planning. Phase II included a curriculum map analysis of profession-specific curricula of the eleven professions: occupational therapy, physiotherapy, speech language pathology and audiology, human nutrition and dietetics, nursing, medicine, radiography, pharmacy, dentistry, dental therapy, and oral hygiene. The curriculum mapping involved consultation with professions’ representatives in combination with information extracted from LOOOP, an electronic curriculum mapping programme. The analysis identified the gaps in addressing interprofessional collaboration core-competencies and highlighted common topics, in the professions’ specific curricula. From the curriculum foundation laid by Phase I and II, an IPECP curriculum framework and design principles were conceptualised using a Curriculum Development Research design. In Phase III, the proposed SMU-IPECP curriculum and accompanying design principles were refined during iterative stages of design, development, testing and revision. Internal and external participants validated the curriculum by rating the relevance, consistency, practicality, and feasibility of the four-year, longitudinal curriculum. A modified Delphi guided consensus on the design principles. The curriculum escalated interprofessional role development from mere exposure to immersion, striving for competent representation in research, ethics and Primary Health care. The build-up followed a trajectory from a professional individualised role in the team, to students fulfilling a dual identity of professional and an interprofessional practice-ready practitioner, who practices in an evidence-based collaborative way as a primary health care advocate, in their final year. The curriculum validation highlighted affordances and constraints for future implementation. During validation, participants agreed on the design and commended the proposed IPECP curriculum. Although the curriculum was planned for a specific university, the theoretical design principles developed through this research process could potentially be customised to fit similar university contexts.Item Tutor-student interaction: how advice is requested, offered, and responded to in an online consultation.(University of the Witwatersrand, Johannesburg, 2024) Tebele, Tebele Sharon; Tam, CatherineIn many university courses, tutors and students engage in online consultations for tutors providing students with academic support. Part of a tutor’s responsibility in such an interaction is to give the student academic advice. Previous studies have been done on how students accept or resist advice in in-person interactions, but the online tutor-student consultation has not been investigated. I focus on advice giving and explore how advice is requested, offered, and responded to in an online tutor-student consultation using an ethnomethodologically informed conversation analytic approach. To do this, I examine a single 27-minute audio recording of an online tutor-student consultation. The session was voluntarily recorded on the online meeting platform and both the tutor and student consented to sharing it with me. Through a tutor-led interrogative sequence, the tutor builds a common ground and establishes an epistemic equilibrium where both tutor and student are knowledgeable about the student’s experiences. Thereafter, the student may issue a troubles telling that shifts the epistemic gradient so that the tutor is in a more knowledgeable position and able to offer advice regarding the trouble. I also investigate an instance where the student does not issue a troubleshooting, and the tutor does not offer advice. My findings align with the recommendations by a previous study that advice-giving can be evaluative: as the tutor only advised after the student had shared their thoughts and knowledge about the topic to determine if there was a need for advice. The findings contribute to the literature on advice sequences in institutional settings by reinforcing prior findings and demonstrating how the tutor used a series of techniques to build common ground and epistemic equilibrium and how the student used a troubles telling to shift the epistemic gradient so the tutor could move into a more knowledgeable position necessary for giving advice. While there has been limited research conducted on advice-giving in face-to-face T-S interactions to my knowledge, there has been no investigation of how advice is accomplished in online T-S consultations to highlight the originality of the current study.Item Comrades on the Road: Stories from South Africa’s Iconic Race(University of the Witwatersrand, Johannesburg, 2024) Brown, Ryan LenoraItem Seeming, being and becoming: an intimate, autoethnographic rasa-led performance art exploration(University of the Witwatersrand, Johannesburg, 2023) Maharajh, Reshma; Khan, Sharlene; Munro, Allan; Andrew, DavidThis thesis focuses on the interplay of "Seeming," "Being," and "Becoming" as it relates to past experiences, present moments and future potentialities. In this project, I delve into the concept of my South African ‘Indianness’ from a personal perspective. As a researcher, I engaged performance art and the aesthetic theory of rasa from the Nātyashāstra a treatise on dramatic theory or the science of drama in Sanskrit (a language of scholarship and philosophy across ancient ‘India’) to explore this concept further. The research encompasses three interconnected practices: rasa, autoethnography, and practice-led research and how central living strategies and concepts are used to define body- mindedness as a life force as emergence in performance strategy. Rasa serves as a guiding metaphor, representing the emotional essence of the artmaking strategies and creative process. These pursuits were not merely cathartic but were about reaching a Transcendental Emotional Moment (TEM) in which "being" and "becoming" converged. Rasa has been proven to be an effective tool in exploring my own identity, subject formation and artmaking, with therapeutic benefits. The second line of inquiry delves into my lived experiences as a widow, mother and practising Hindu, highlighting the complexity of South African Indianness and seeks to bridge the gap between "seeming" and "being" while anticipating what might "become" through the lens of rasa. The third line of inquiry revolves around the practice of performance art (combined with autoethnographic reflection), exploring the tensions between two philosophic models of Integrity and Intimacy as proposed by Kasulis (2002). As the artist (both creator and subject), my life and body became the canvas upon which the artwork unfolded. Performance art allowed for a moment of being when the artwork and I came into existence for each other. This process required cognitive and creative engagement with the project’s content, drawing on past experiences, culture, relationships, politics and religion, guided by rasa. The goal created an environment in which the ‘Oneness of Being’ emerged, leading to a TEM in performance. This moment invited the potential for refreshed, emergent insights and meaning through autoethnography and practice-led research. The “Seeming, Being and Becoming” trajectory and the efficacy of the rasa roadmap is proposed as a cultural philosophy that promotes human flourishing, culminating in the moment of TEM.Item So, where to (So-we-to) with audiences? An explorative inquiry into audience development strategies at Soweto Theatre in the period 2019-2023(University of the Witwatersrand, Johannesburg, 2024) Mogotsi, Ratanang; Mavhungu, JohannaTheatre does not exist without an audience; it is imperative that theatre’s find new and innovative strategies that will develop audiences as the sector continues to face a drop in theatre attendance. Through a qualitative inquiry and Soweto Theatre as the case study, this research explores audience development strategies implemented at Soweto Theatre between 2019 and 2023. This period saw the biggest decline in theatre audiences across the theatre sector in South Africa and abroad due to the effects of the Covid-19 pandemic. The findings reveal the necessity of organisational restructuring, improved internal and external communication among the staff, clear task allocation and role management, as well as strategic management alignment in order to improve its audience development strategies. Storytelling is introduced as one of the key concepts to audience development. Storytelling integrates more process-related content into marketing initiatives such as social media which allows for audiences to get a taste of what to expect and to be a part of the storytelling process. Soweto Theatre, symbolises a catalyst for cultural democracy, fostering social cohesion and community empowerment. This research report concludes that digital platforms such as social media can be used to disseminate information, for outreach, arts education and cultural inclusion. Furthermore, nurturing young talent, and forging sustainable partnerships is pivotal in democratising the arts and cultivating a more inclusive cultural space. Collaboration among arts organisations and youth development programs across various theatres can further enrich experiences and heighten opportunities for emerging artists, contributing to the growth of audiences in South Africa's dynamic creative and cultural industries.