A framework for designing a gamified system that promotes knowledge of water sustainability
- Authors: Kunjuzwa, Dumani Tau
- Date: 2024-12
- Subjects: Computer science , User interfaces (Computer systems) , Water-supply -- Management
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69349 , vital:77216
- Description: Water shortages are becoming increasingly common and raising awareness thereof has been proposed as a key strategy for empowering citizens with knowledge relevant to promoting water sustainability. This knowledge should incorporate indigenous knowledge, which is unique and confined to a particular culture. Indigenous knowledge has been recognised as the key to sustainable social and economic development. Knowledge incorporated within appropriate technologies can be a transformative solution to promote sustainable consumption of natural resources. This study aimed to develop a framework with strong theoretical connections that can be used as a guide for designing and developing technological solutions for promoting knowledge, attitude, and practices (KAP) of water sustainability. Gamification, serious games, and community social networks were identified as appropriate technologies for implementing these solutions. Design Science Research (DSR) was an appropriate research methodology for this research. As the requirement of the DSR methodology, a framework was designed that considered relevant theories. The two theories (Self-Determination Theory and Social Capital Theory) were incorporated into the framework. The framework can guide other researchers in developing gamified systems that promote the KAPs of water sustainability. This framework was the theoretical artefact of the study. The research context was the Eastern Cape Province of South Africa where the data was collected from two municipalities namely, the Nelson Mandela Bay and Buffalo City Metro, which have both experienced water shortages in recent years. Quantitative and qualitative data collection methods were used. Qualitative data was collected from brainstorming sessions and expert reviews that were conducted with various stakeholders that assisted with designing and evaluating the prototype designs of the gamified solution. For the design of the study’s artefacts, a participatory research approach was adopted. Participants were recruited to complete an online survey, which ran for three months. The findings revealed that citizens’ knowledge is closely correlated to the attitudes and practices of citizens regarding water sustainability. In addition, the findings showed that the knowledge of the citizens in the Eastern Cape Province was relatively low on water practices such as conservation and filtering methods. These results were considered in the design of the practical artefact and the instantiation findings. One limitation of this study was the limited number of indigenous participants in the survey. Other limitations were the lack of experts with indigenous knowledge and the lack of indigenous knowledge documentation. The promotion of water sustainability knowledge in communities would be more effective with the use of gamification and social community networks. In principle, the enhancement in water sustainability knowledge would promote the citizens’ good practices and attitudes (behavioural) related to water sustainability. Since 2015, a significant portion of South Africa's Eastern Cape Province has been suffering from a severe drought. This province is one of the regions of the country where weather patterns have changed dramatically, and as a result, most households were left vulnerable to the water shortage problem. While the broad topic of water sustainability is widely discussed in the literature, the role of appropriate technologies in promoting knowledge of water sustainability is still under-researched. This gap provided a significant potential for investigation by sustainability to design a technological and theoretical solution for promoting knowledge of water sustainability. This study contributes to the body of knowledge by delivering three DSR artefacts namely, a Framework for Designing a Gamified System that Promotes Knowledge of Water Sustainability; the design guidelines that supplement the framework, and a practical instantiation of the framework. , Thesis (DPhil) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Kunjuzwa, Dumani Tau
- Date: 2024-12
- Subjects: Computer science , User interfaces (Computer systems) , Water-supply -- Management
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69349 , vital:77216
- Description: Water shortages are becoming increasingly common and raising awareness thereof has been proposed as a key strategy for empowering citizens with knowledge relevant to promoting water sustainability. This knowledge should incorporate indigenous knowledge, which is unique and confined to a particular culture. Indigenous knowledge has been recognised as the key to sustainable social and economic development. Knowledge incorporated within appropriate technologies can be a transformative solution to promote sustainable consumption of natural resources. This study aimed to develop a framework with strong theoretical connections that can be used as a guide for designing and developing technological solutions for promoting knowledge, attitude, and practices (KAP) of water sustainability. Gamification, serious games, and community social networks were identified as appropriate technologies for implementing these solutions. Design Science Research (DSR) was an appropriate research methodology for this research. As the requirement of the DSR methodology, a framework was designed that considered relevant theories. The two theories (Self-Determination Theory and Social Capital Theory) were incorporated into the framework. The framework can guide other researchers in developing gamified systems that promote the KAPs of water sustainability. This framework was the theoretical artefact of the study. The research context was the Eastern Cape Province of South Africa where the data was collected from two municipalities namely, the Nelson Mandela Bay and Buffalo City Metro, which have both experienced water shortages in recent years. Quantitative and qualitative data collection methods were used. Qualitative data was collected from brainstorming sessions and expert reviews that were conducted with various stakeholders that assisted with designing and evaluating the prototype designs of the gamified solution. For the design of the study’s artefacts, a participatory research approach was adopted. Participants were recruited to complete an online survey, which ran for three months. The findings revealed that citizens’ knowledge is closely correlated to the attitudes and practices of citizens regarding water sustainability. In addition, the findings showed that the knowledge of the citizens in the Eastern Cape Province was relatively low on water practices such as conservation and filtering methods. These results were considered in the design of the practical artefact and the instantiation findings. One limitation of this study was the limited number of indigenous participants in the survey. Other limitations were the lack of experts with indigenous knowledge and the lack of indigenous knowledge documentation. The promotion of water sustainability knowledge in communities would be more effective with the use of gamification and social community networks. In principle, the enhancement in water sustainability knowledge would promote the citizens’ good practices and attitudes (behavioural) related to water sustainability. Since 2015, a significant portion of South Africa's Eastern Cape Province has been suffering from a severe drought. This province is one of the regions of the country where weather patterns have changed dramatically, and as a result, most households were left vulnerable to the water shortage problem. While the broad topic of water sustainability is widely discussed in the literature, the role of appropriate technologies in promoting knowledge of water sustainability is still under-researched. This gap provided a significant potential for investigation by sustainability to design a technological and theoretical solution for promoting knowledge of water sustainability. This study contributes to the body of knowledge by delivering three DSR artefacts namely, a Framework for Designing a Gamified System that Promotes Knowledge of Water Sustainability; the design guidelines that supplement the framework, and a practical instantiation of the framework. , Thesis (DPhil) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2024
- Full Text:
- Date Issued: 2024-12
A multistep synthesis of zidovudine in continuous flow systems
- Authors: Kwakhanya, Mkwakwi
- Date: 2024-12
- Subjects: HIV -- South Africa , HIV infections -- Diagnosis , Antiretroviral agents -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69393 , vital:77251
- Description: Universal access to antiretroviral drugs is still a challenge in developing nations. This promoted an investigation into an efficient process towards the synthesis of zidovudine (AZT), a nucleoside reverse transcriptase inhibitor (NRTI) that is used to treat HIV/AIDS. It was the first antiretroviral drug approved by the FDA and it is still widely used today. AZT works by blocking the enzyme reverse transcriptase, which is used by HIV to copy its genetic material. This prevents HIV from replicating and spreading throughout the body. AZT is usually taken in combination with other antiretroviral drugs. AZT was originally used as a single-drug therapy, but it is no longer recommended for this purpose as HIV can become resistant to AZT if it is used alone. Consequently, AZT is most commonly used as part of a combination therapy; this means that it is taken with other antiretroviral drugs. This helps to prevent HIV from becoming resistant to AZT. AZT can be used to prevent mother-to-child transmission of HIV; it is usually given to HIV-positive women during pregnancy and childbirth. AZT can also be used to treat post-exposure prophylaxis (PEP); this is a course of antiretroviral drugs that is taken after a possible exposure to HIV. The application of continuous flow microreactors to reaction chemistries, such as this, could provide a potentially practical solution that could be used to meet the rising needs for antiretroviral drugs in Africa and to give new opportunities for efficient local drug manufacture. Consequently, the focus of this research was to develop safe and efficient processes towards AZT by taking advantage of micro reactor technology. Furthermore, since there is no literature on continuous flow synthesis of this drug, this research extensively unearthed interesting continuous flow processes towards zidovudine. , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Kwakhanya, Mkwakwi
- Date: 2024-12
- Subjects: HIV -- South Africa , HIV infections -- Diagnosis , Antiretroviral agents -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69393 , vital:77251
- Description: Universal access to antiretroviral drugs is still a challenge in developing nations. This promoted an investigation into an efficient process towards the synthesis of zidovudine (AZT), a nucleoside reverse transcriptase inhibitor (NRTI) that is used to treat HIV/AIDS. It was the first antiretroviral drug approved by the FDA and it is still widely used today. AZT works by blocking the enzyme reverse transcriptase, which is used by HIV to copy its genetic material. This prevents HIV from replicating and spreading throughout the body. AZT is usually taken in combination with other antiretroviral drugs. AZT was originally used as a single-drug therapy, but it is no longer recommended for this purpose as HIV can become resistant to AZT if it is used alone. Consequently, AZT is most commonly used as part of a combination therapy; this means that it is taken with other antiretroviral drugs. This helps to prevent HIV from becoming resistant to AZT. AZT can be used to prevent mother-to-child transmission of HIV; it is usually given to HIV-positive women during pregnancy and childbirth. AZT can also be used to treat post-exposure prophylaxis (PEP); this is a course of antiretroviral drugs that is taken after a possible exposure to HIV. The application of continuous flow microreactors to reaction chemistries, such as this, could provide a potentially practical solution that could be used to meet the rising needs for antiretroviral drugs in Africa and to give new opportunities for efficient local drug manufacture. Consequently, the focus of this research was to develop safe and efficient processes towards AZT by taking advantage of micro reactor technology. Furthermore, since there is no literature on continuous flow synthesis of this drug, this research extensively unearthed interesting continuous flow processes towards zidovudine. , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Achievement in mathematics through self-directed learning facilitation: an impact evaluation of an offline technological approach
- Authors: Zinn, Paméla Olive
- Date: 2024-12
- Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa , Mathematical ability , Academic achievement -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68385 , vital:76992
- Description: International assessments indicate that mathematics education in South Africa is still in a crisis of significant proportions. This is reflected in the low pass rate of Grade 12 mathematics learners in South Africa in general, and in the Eastern Cape Province in particular. In response, the Govan Mbeki Mathematics Development Center (GMMDC) of the Nelson Mandela University (NMU) in the Eastern Cape developed an intervention strategy. A Techno-Blended support Model for teaching and learning mathematics (TBM), used as an intervention strategy, provides learners with potential from disadvantaged communities and under-resourced schools with 21st-century education technology. The defining features of the strategy which distinguishes it from others are that it is technology-enhanced, providing the learner access to mathematics teaching and learning without the need for Internet connectivity, that is, offline, incorporating blended learning into the approach. This ex-post study, using secondary analysis, evaluates the impact of the defining features of the strategy on learners' self-directed learning skills acquisition or enhancement for mathematics learning. Firstly, statistical analysis of secondary qualitative and quantitative data in a mixed methods approach, with primary qualitative data integrated into the secondary qualitative data employing quantification, is undertaken. The quantified data is then compared with the quantitative data (methodologic triangulation technique). Secondly, the theory-based Contribution Analysis is undertaken to increase the validity and credibility of the findings of the statistical analysis, providing an additional layer of triangulation. The study revealed that providing 21st-century digital education technology for use offline, within a blended learning environment, leads to a significant improvement in learner mathematics knowledge; conceptual understanding; positive self-perceptions; and finally, to the required intrinsic motivation to learn. Analysed data, obtained from the original study, indicates a positive correlation between learners who participated in the intervention strategy and enrolment in STEM-related courses at tertiary institutes. , Thesis (DPhil) -- Faculty of Education, School of Postgraduate education, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Zinn, Paméla Olive
- Date: 2024-12
- Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa , Mathematical ability , Academic achievement -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68385 , vital:76992
- Description: International assessments indicate that mathematics education in South Africa is still in a crisis of significant proportions. This is reflected in the low pass rate of Grade 12 mathematics learners in South Africa in general, and in the Eastern Cape Province in particular. In response, the Govan Mbeki Mathematics Development Center (GMMDC) of the Nelson Mandela University (NMU) in the Eastern Cape developed an intervention strategy. A Techno-Blended support Model for teaching and learning mathematics (TBM), used as an intervention strategy, provides learners with potential from disadvantaged communities and under-resourced schools with 21st-century education technology. The defining features of the strategy which distinguishes it from others are that it is technology-enhanced, providing the learner access to mathematics teaching and learning without the need for Internet connectivity, that is, offline, incorporating blended learning into the approach. This ex-post study, using secondary analysis, evaluates the impact of the defining features of the strategy on learners' self-directed learning skills acquisition or enhancement for mathematics learning. Firstly, statistical analysis of secondary qualitative and quantitative data in a mixed methods approach, with primary qualitative data integrated into the secondary qualitative data employing quantification, is undertaken. The quantified data is then compared with the quantitative data (methodologic triangulation technique). Secondly, the theory-based Contribution Analysis is undertaken to increase the validity and credibility of the findings of the statistical analysis, providing an additional layer of triangulation. The study revealed that providing 21st-century digital education technology for use offline, within a blended learning environment, leads to a significant improvement in learner mathematics knowledge; conceptual understanding; positive self-perceptions; and finally, to the required intrinsic motivation to learn. Analysed data, obtained from the original study, indicates a positive correlation between learners who participated in the intervention strategy and enrolment in STEM-related courses at tertiary institutes. , Thesis (DPhil) -- Faculty of Education, School of Postgraduate education, 2024
- Full Text:
- Date Issued: 2024-12
Associations between patterns of wild ungulate patch use, soil carbon and albedo in montane grasslands
- Authors: Mc Gregor, Steven
- Date: 2024-12
- Subjects: Grassland ecology , Global environmental change , Climatic changes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69382 , vital:77250
- Description: Grassy ecosystems are essential for human survival, providing key services including food production, water provisioning and moderating climate. Yet, grassy ecosystems remain undervalued due to misconceptions that they are remnants of degraded states of forest – a view that continues to influence climate change policies. This thesis explores the links between wild, free-roaming ungulate grazers and climate drivers, including carbon storage and surface albedo (i.e., reflectance of solar radiation), through their impacts on vegetation and soils. Using black wildebeest (Connochaetes gnou) as a model wild species, I compared their grazing patterns in an Afromontane grassland in the eastern Karoo, South Africa, to those of short-duration cattle grazing systems in similar nearby grasslands (Chapter 2). While short-duration grazing aims to mimic spatiotemporal wild ungulate grazing patterns to supposedly enhance ecosystem functioning and soil carbon stocks, I found that wildebeest had ~50% shorter grazing durations and much shorter rest intervals (1-5 days versus 60-365 days), revealing key differences in grazing patterns that may affect vegetation and climate feedbacks. Next, I examined spatial variations in soil organic carbon (SOC) stocks between grass growth forms that differ in grazing tolerance (Chapter 3). Red grass (Themeda triandra) tussock patches, sensitive to frequent grazing, had higher SOC to a soil depth of 20 cm (61.45 ± 1.59 Mg C·ha-1)than intensively grazed, prostrate-growing Cynodon dactylon grazing lawns (55.43 ± 3.40Mg C·ha-1), likely due to greater shading and soil moisture beneath tussocks which drives microbial decomposition. Seasonal albedo variations were then assessed across distinct grassland patch types among seasons to determine whether albedo varies seasonally at fine patch-scales between grass patches, between shrub and grass patches, and with grazing (Chapter 4). Albedo was lower during the growing season compared to dormancy, and was consistently lower in dwarf shrub (Pentzia incana) encroached patches compared to grass patches. No albedo differences between grazed and less-grazed tussock grass patches of the same species were found, although intensively grazed grazing lawns had consistently higher albedo than most patch types. Finally, I evaluated trade-offs between plant carbon, albedo, and their impacts on radiative forcing (i.e., atmospheric warming/cooling) resulting from patch type changes commonly found in grassy ecosystems (Chapter 5). The loss of perennial grass cover resulted in the highest net positive (warming) effect, mostly due to reduced root biomass. Additionally, shrub encroachment into all patches lowered albedo, but led to negative (cooling) effects from shrub encroachment into bare ground patches due to biomass gains. This thesis challenges current views of grassy landscapes and short-duration grazing systems, emphasizing the need to rethink climate change mitigation strategies to prioritize maintaining heterogeneity, while enhancing carbon sequestration and albedo in grassy ecosystems. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Mc Gregor, Steven
- Date: 2024-12
- Subjects: Grassland ecology , Global environmental change , Climatic changes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69382 , vital:77250
- Description: Grassy ecosystems are essential for human survival, providing key services including food production, water provisioning and moderating climate. Yet, grassy ecosystems remain undervalued due to misconceptions that they are remnants of degraded states of forest – a view that continues to influence climate change policies. This thesis explores the links between wild, free-roaming ungulate grazers and climate drivers, including carbon storage and surface albedo (i.e., reflectance of solar radiation), through their impacts on vegetation and soils. Using black wildebeest (Connochaetes gnou) as a model wild species, I compared their grazing patterns in an Afromontane grassland in the eastern Karoo, South Africa, to those of short-duration cattle grazing systems in similar nearby grasslands (Chapter 2). While short-duration grazing aims to mimic spatiotemporal wild ungulate grazing patterns to supposedly enhance ecosystem functioning and soil carbon stocks, I found that wildebeest had ~50% shorter grazing durations and much shorter rest intervals (1-5 days versus 60-365 days), revealing key differences in grazing patterns that may affect vegetation and climate feedbacks. Next, I examined spatial variations in soil organic carbon (SOC) stocks between grass growth forms that differ in grazing tolerance (Chapter 3). Red grass (Themeda triandra) tussock patches, sensitive to frequent grazing, had higher SOC to a soil depth of 20 cm (61.45 ± 1.59 Mg C·ha-1)than intensively grazed, prostrate-growing Cynodon dactylon grazing lawns (55.43 ± 3.40Mg C·ha-1), likely due to greater shading and soil moisture beneath tussocks which drives microbial decomposition. Seasonal albedo variations were then assessed across distinct grassland patch types among seasons to determine whether albedo varies seasonally at fine patch-scales between grass patches, between shrub and grass patches, and with grazing (Chapter 4). Albedo was lower during the growing season compared to dormancy, and was consistently lower in dwarf shrub (Pentzia incana) encroached patches compared to grass patches. No albedo differences between grazed and less-grazed tussock grass patches of the same species were found, although intensively grazed grazing lawns had consistently higher albedo than most patch types. Finally, I evaluated trade-offs between plant carbon, albedo, and their impacts on radiative forcing (i.e., atmospheric warming/cooling) resulting from patch type changes commonly found in grassy ecosystems (Chapter 5). The loss of perennial grass cover resulted in the highest net positive (warming) effect, mostly due to reduced root biomass. Additionally, shrub encroachment into all patches lowered albedo, but led to negative (cooling) effects from shrub encroachment into bare ground patches due to biomass gains. This thesis challenges current views of grassy landscapes and short-duration grazing systems, emphasizing the need to rethink climate change mitigation strategies to prioritize maintaining heterogeneity, while enhancing carbon sequestration and albedo in grassy ecosystems. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Characterization of the molecular mechanism(s) of cannabinoid-induced paraptosis in breast cancer cells
- Authors: de la Harpe, Amy
- Date: 2024-12
- Subjects: Cannabinoids , Cannabinoids -- Therapeutic use , Cancer cells
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68818 , vital:77120
- Description: Natural products have been extensively studied for their anticancer potential, and several widely used anticancer drugs have natural origins. Many studies have demonstrated that natural compounds can induce paraptosis in various tumour cell lines. Paraptosis is a caspase-independent cell death mechanism characterised by cytoplasmic vacuolation arising from the endoplasmic reticulum (ER) and the mitochondria. The molecular mechanism of paraptosis is unclear; however, the literature indicates that dysregulation of calcium signalling plays an important role in paraptosis induction, particularly calcium-mediated signalling between the ER and mitochondria. This study aimed to identify and characterise the mechanism of cell death induced by a phytocannabinoid ratio which induced significant cytoplasmic vacuolation in the MCF7 breast cancer cell line. Several techniques were employed to address the aim of the study. The crystal violet assay was used to detect changes in viability. Several pathway inhibitors, as well as fluorescent staining and analysis using high-content screening (HCS), were used to measure the induction of various cell death mechanisms. Morphological changes were investigated using light and transmission electron microscopy. The phytocannabinoid ratio induced significant cell death and cytoplasmic vacuolation in MCF7 cells; however, the same trend was not observed in the MCF10A non-tumourigenic breast cell line. No cell cycle arrest, apoptosis, necrosis, autophagy, or ferroptosis induction was detected in MCF7 cells, suggesting that an alternative mechanism of cell death was induced. Vacuolation and cell death induced by the phytocannabinoid ratio were inhibited by cycloheximide, suggesting a dependence on protein synthesis, which is characteristic of paraptosis induction. The mechanism of paraptosis induction by the phytocannabinoid ratio was investigated, and it was found that treatment 1) induced ER dilation and mitochondrial swelling; 2) induced significant ER stress, mitochondrial calcium overload, and mitochondrial dysfunction which appeared to be mediated by the voltage-dependent anion channel (VDAC); and 3) significantly impaired all mitochondrial metabolic pathways. Overall, the data demonstrated that paraptosis induced by the cannabinoid ratio is mediated by calcium flux from the ER to the mitochondria. This highlighted a novel mechanism of phytocannabinoid-induced cell death and emphasised the anti-cancer potential of the use of phytocannabinoid ratios as opposed to individual phytocannabinoids, expanding their potential for use as anticancer agents. , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: de la Harpe, Amy
- Date: 2024-12
- Subjects: Cannabinoids , Cannabinoids -- Therapeutic use , Cancer cells
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68818 , vital:77120
- Description: Natural products have been extensively studied for their anticancer potential, and several widely used anticancer drugs have natural origins. Many studies have demonstrated that natural compounds can induce paraptosis in various tumour cell lines. Paraptosis is a caspase-independent cell death mechanism characterised by cytoplasmic vacuolation arising from the endoplasmic reticulum (ER) and the mitochondria. The molecular mechanism of paraptosis is unclear; however, the literature indicates that dysregulation of calcium signalling plays an important role in paraptosis induction, particularly calcium-mediated signalling between the ER and mitochondria. This study aimed to identify and characterise the mechanism of cell death induced by a phytocannabinoid ratio which induced significant cytoplasmic vacuolation in the MCF7 breast cancer cell line. Several techniques were employed to address the aim of the study. The crystal violet assay was used to detect changes in viability. Several pathway inhibitors, as well as fluorescent staining and analysis using high-content screening (HCS), were used to measure the induction of various cell death mechanisms. Morphological changes were investigated using light and transmission electron microscopy. The phytocannabinoid ratio induced significant cell death and cytoplasmic vacuolation in MCF7 cells; however, the same trend was not observed in the MCF10A non-tumourigenic breast cell line. No cell cycle arrest, apoptosis, necrosis, autophagy, or ferroptosis induction was detected in MCF7 cells, suggesting that an alternative mechanism of cell death was induced. Vacuolation and cell death induced by the phytocannabinoid ratio were inhibited by cycloheximide, suggesting a dependence on protein synthesis, which is characteristic of paraptosis induction. The mechanism of paraptosis induction by the phytocannabinoid ratio was investigated, and it was found that treatment 1) induced ER dilation and mitochondrial swelling; 2) induced significant ER stress, mitochondrial calcium overload, and mitochondrial dysfunction which appeared to be mediated by the voltage-dependent anion channel (VDAC); and 3) significantly impaired all mitochondrial metabolic pathways. Overall, the data demonstrated that paraptosis induced by the cannabinoid ratio is mediated by calcium flux from the ER to the mitochondria. This highlighted a novel mechanism of phytocannabinoid-induced cell death and emphasised the anti-cancer potential of the use of phytocannabinoid ratios as opposed to individual phytocannabinoids, expanding their potential for use as anticancer agents. , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Construction material waste control success model for the construction industry
- Authors: Musah, Abdul Razak
- Date: 2024-12
- Subjects: Construction industry -- Materials management , Construction industry -- Management , Construction industry -- Environmental aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68796 , vital:77114
- Description: Economic sustainability and reconstruction in many economies rely heavily on the construction sector and remain strategic tools for governments and industries worldwide. Excessive construction costs and materials waste among some construction companies are rampant in the construction sector. Most of this waste is poorly managed, thus triggering significant project failure problems, leading to the project stakeholders losing the value of their investment. This concern advocate for effective control of construction material to avoid wastage. The primary objective of this study was to develop a Construction Waste Material Control (CWMC) model to be used by construction project professionals throughout the Project Management (PM) phases: initiation, planning, execution, monitoring, control and closure. Significant literature on construction materials waste, Project Management (PM) processes, and project performance regarding poor waste management and project failure was reviewed. This literature review was conducted to identify factors affecting Construction Waste Material Control (CWMC). These factors were identified and defined together with their respective contributions to the model. A quantitative survey instrument (questionnaire) was used to obtain information from construction sector professionals. A total of 213 questionnaire were received and administered for the study. Structural Equation Model (SEM) SEM was used to analyse the questionnaire data, and thereby assisting the research to clearly define latent constructs statistically significant to the (CWMC) model. The finding was that, the factors identified to have impact on CWMC are Project Initiation Phase Tools (PIPTs), Project Planning Phase Tools (PPPTs), project failure/success factors (PFFs), Project Execution Phase Tools (PEPTs), Project Monitoring and Control Phase Tools (PMCPTs), Construction waste material Control (CWMC) policy and Project Management (PM) competence. The supported hypotheses also authenticated these factors. Introducing the model into the construction sector provides another dimension to CWMC. By establishing the aforementioned factors, the model gives construction professionals precise CWMC predictive accuracy. As the model reliability test of 0.734 to 0.972 satisfied the theoretical threshold and goodness of fit of 0.912 of Normed fit index respectively. The model is the first of its kind and contributes significantly to the construction sector’s existing body of knowledge. , Thesis (PhD) -- Faculty of Engineering, the Built Environment, and Technology, School of Built Environment and Civil Engineering, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Musah, Abdul Razak
- Date: 2024-12
- Subjects: Construction industry -- Materials management , Construction industry -- Management , Construction industry -- Environmental aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68796 , vital:77114
- Description: Economic sustainability and reconstruction in many economies rely heavily on the construction sector and remain strategic tools for governments and industries worldwide. Excessive construction costs and materials waste among some construction companies are rampant in the construction sector. Most of this waste is poorly managed, thus triggering significant project failure problems, leading to the project stakeholders losing the value of their investment. This concern advocate for effective control of construction material to avoid wastage. The primary objective of this study was to develop a Construction Waste Material Control (CWMC) model to be used by construction project professionals throughout the Project Management (PM) phases: initiation, planning, execution, monitoring, control and closure. Significant literature on construction materials waste, Project Management (PM) processes, and project performance regarding poor waste management and project failure was reviewed. This literature review was conducted to identify factors affecting Construction Waste Material Control (CWMC). These factors were identified and defined together with their respective contributions to the model. A quantitative survey instrument (questionnaire) was used to obtain information from construction sector professionals. A total of 213 questionnaire were received and administered for the study. Structural Equation Model (SEM) SEM was used to analyse the questionnaire data, and thereby assisting the research to clearly define latent constructs statistically significant to the (CWMC) model. The finding was that, the factors identified to have impact on CWMC are Project Initiation Phase Tools (PIPTs), Project Planning Phase Tools (PPPTs), project failure/success factors (PFFs), Project Execution Phase Tools (PEPTs), Project Monitoring and Control Phase Tools (PMCPTs), Construction waste material Control (CWMC) policy and Project Management (PM) competence. The supported hypotheses also authenticated these factors. Introducing the model into the construction sector provides another dimension to CWMC. By establishing the aforementioned factors, the model gives construction professionals precise CWMC predictive accuracy. As the model reliability test of 0.734 to 0.972 satisfied the theoretical threshold and goodness of fit of 0.912 of Normed fit index respectively. The model is the first of its kind and contributes significantly to the construction sector’s existing body of knowledge. , Thesis (PhD) -- Faculty of Engineering, the Built Environment, and Technology, School of Built Environment and Civil Engineering, 2024
- Full Text:
- Date Issued: 2024-12
Development of density-dependent and density-independent competition models to understand single tree growth responses in eucalyptus stands
- Authors: Kepe, Lulama Patrick
- Date: 2024-12
- Subjects: Forests and forestry -- Mathematical models , Trees -- Growth -- Mathematical models , Eucalyptus grandis
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68906 , vital:77161
- Description: In commercial forest production, predicted yields based on mensuration recommendations are seldom realized, and minimal silvicultural standards based on results from trial blocks do not account for the relationship between initial planting density and final stocking. Growth models designed to investigate management options must employ competition indices to provide reliable predictions under extreme silviculture. The competition a tree experiences until the day of harvest is a strong driver for quality and volume of timber. Hence, this turns the regulation of competition into an integral part of silviculture. According to Little et al. (2003), it is known that, at some stage after canopy closure, individual trees in a stand will begin to compete for resources. To investigate competition amongst individual trees, a re-purposed Bayesian mixed effects model, similar in characteristics to a Sire model used for estimating breeding values, is proposed. In animal breeding models, the Sire Model allows for the inclusion of a numerator relationship matrix containing inbreeding coefficients. In a similar way, documented competition indices are included in the model in an attempt to estimate posterior probabilities of specifically selected individual trees being the strongest growers during different stages in the tree growth cycle. Estimated tree growth indices were determined and used to make probability statements in order to rank the individually selected trees based on the amount of growth observed. A tree growth index is a measurement of a tree’s average growth performance in relation to the average growth performance of all trees on the same plot. As different competition indices are introduced into the model, changes in the probabilities are observed and compared to what is visually observed on the plot, i.e. if the tree with the highest probability of being the strongest grower, is actually not necessarily the largest tree of the group of selected trees, but rather the tree that presented the largest amount of growth of the selected group of trees during that specific growth season. From a randomly selected plot, a group of neighboring trees were randomly selected. Four specifically selected target trees were then identified from this group of 25 selected trees, and analyzed. For this discussion, for example, from our randomly selected group of 25 neighboring trees, tree 54, tree 56, tree 86, and tree 88 were specifically selected for further analysis. For these specifically selected trees, marginal posterior densities for the variance components and random effects were then estimated using the Gibbs Sampler, where competition between the trees was assumed present, as well as for the case where it was assumed that no competition takes place between the individually selected trees. In the latter case, an identity matrix was utilized in the Gibbs sampling algorithm where it was assumed that there is no competition between the trees. Both a distance independent competition index (Lorimer,1983), and a distance dependent index (Hegyi, 1974), were used to generate the numerator relationship matrix A that was used by the Gibbs sampling algorithm in the case where competition was assumed between individual trees. Also a new distance dependent index was proposed and tested in this study as well. Results from the selected plot, with a 1500 stems per hectare (sph) density, indicated that there were no significant differences in the average growth between these selected trees. However, the marginal posterior densities of the fixed effects indicated that there was a significant difference in the average growth rates between the base level conditions and other levels determined for each of these fixed effect factors for the selected trees, since their 95% equal tails credibility intervals, did not contain zero. This therefore indicated that the specific treatment applied on the plot, had a significant effect on the individual tree growth. Results when competition was assumed present, revealed that the estimated marginal posterior densities for the error variance as well as tree variance, were severely positively skewed. , Thesis (PhD) -- Faculty of Science, School of Natural Resource Science & Management, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Kepe, Lulama Patrick
- Date: 2024-12
- Subjects: Forests and forestry -- Mathematical models , Trees -- Growth -- Mathematical models , Eucalyptus grandis
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68906 , vital:77161
- Description: In commercial forest production, predicted yields based on mensuration recommendations are seldom realized, and minimal silvicultural standards based on results from trial blocks do not account for the relationship between initial planting density and final stocking. Growth models designed to investigate management options must employ competition indices to provide reliable predictions under extreme silviculture. The competition a tree experiences until the day of harvest is a strong driver for quality and volume of timber. Hence, this turns the regulation of competition into an integral part of silviculture. According to Little et al. (2003), it is known that, at some stage after canopy closure, individual trees in a stand will begin to compete for resources. To investigate competition amongst individual trees, a re-purposed Bayesian mixed effects model, similar in characteristics to a Sire model used for estimating breeding values, is proposed. In animal breeding models, the Sire Model allows for the inclusion of a numerator relationship matrix containing inbreeding coefficients. In a similar way, documented competition indices are included in the model in an attempt to estimate posterior probabilities of specifically selected individual trees being the strongest growers during different stages in the tree growth cycle. Estimated tree growth indices were determined and used to make probability statements in order to rank the individually selected trees based on the amount of growth observed. A tree growth index is a measurement of a tree’s average growth performance in relation to the average growth performance of all trees on the same plot. As different competition indices are introduced into the model, changes in the probabilities are observed and compared to what is visually observed on the plot, i.e. if the tree with the highest probability of being the strongest grower, is actually not necessarily the largest tree of the group of selected trees, but rather the tree that presented the largest amount of growth of the selected group of trees during that specific growth season. From a randomly selected plot, a group of neighboring trees were randomly selected. Four specifically selected target trees were then identified from this group of 25 selected trees, and analyzed. For this discussion, for example, from our randomly selected group of 25 neighboring trees, tree 54, tree 56, tree 86, and tree 88 were specifically selected for further analysis. For these specifically selected trees, marginal posterior densities for the variance components and random effects were then estimated using the Gibbs Sampler, where competition between the trees was assumed present, as well as for the case where it was assumed that no competition takes place between the individually selected trees. In the latter case, an identity matrix was utilized in the Gibbs sampling algorithm where it was assumed that there is no competition between the trees. Both a distance independent competition index (Lorimer,1983), and a distance dependent index (Hegyi, 1974), were used to generate the numerator relationship matrix A that was used by the Gibbs sampling algorithm in the case where competition was assumed between individual trees. Also a new distance dependent index was proposed and tested in this study as well. Results from the selected plot, with a 1500 stems per hectare (sph) density, indicated that there were no significant differences in the average growth between these selected trees. However, the marginal posterior densities of the fixed effects indicated that there was a significant difference in the average growth rates between the base level conditions and other levels determined for each of these fixed effect factors for the selected trees, since their 95% equal tails credibility intervals, did not contain zero. This therefore indicated that the specific treatment applied on the plot, had a significant effect on the individual tree growth. Results when competition was assumed present, revealed that the estimated marginal posterior densities for the error variance as well as tree variance, were severely positively skewed. , Thesis (PhD) -- Faculty of Science, School of Natural Resource Science & Management, 2024
- Full Text:
- Date Issued: 2024-12
Exploiting continuous flow technology to develop synthetic processes for active pharmaceutical ingredients: prilocaine and betrixaban
- Authors: Sagandira, Mellisa Brenda
- Date: 2024-12
- Subjects: Pharmaceutical technology , Drug development , Pharmaceutical biotechnology
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69464 , vital:77259
- Description: The dilemma of providing affordable health care has long haunted African countries due to the continuously growing disease burden as the population increases. Africa accounts for only 3 % of global drug production and imports over 90 % of its life saving medicines at a yearly cost of US$14 billion according to the African Development Bank (AfDB). Attaining Africa’s Agenda 2063, Universal Health Coverage (UHC) and Sustainable development Goal 3 (SDG3) aspirations of ensuring healthy and well-nourished citizens remain difficult given this situation. This over-dependence on imports has led to drug shortages, high pricing, poor quality medicines and unguaranteed supply chains, thus there still remains an unmet need. The advent of the COVID-19 pandemic worsened this situation as many countries curbed exports resulting in a crisis across the continent. Africa experienced high demand of medicines compared to prepandemic level, which threatened the health care of the continent. This situation can be addressed by establishment of local pharmaceutical manufacturing capability through adoption of advanced manufacturing technologies such as continuous flow chemistry. In this research, we therefore seek to exploit continuous flow chemistry, an enabling technology to develop safe and efficient synthetic processes for active pharmaceutical ingredients: prilocaine and betrixaban as case studies. To the best of our knowledge there is no reported work on synthetic processes towards prilocaine and betrixaban under continuous flow conditions, thus this research extensively unearthed interesting continuous flow processes towards these APIs. In a broader view, establishment of local APIs production will ease Africa’s over-dependence on imports, which will in turn address issues such as drug shortages, poor quality and high pricing. This work aims to demonstrate how continuous flow technology can be useful for the establishment of local APIs manufacturing, which will inherently revolutionize medicines availability, affordability and accessibility to the greater population. Chapter one begins with a brief overview on Africa’s disease burden and pharmaceutical supply chain. Continuous flow chemistry is introduced with its benefits and limitations discussed. Lastly a mini review of examples of APIs synthesised in continuous flow is presented. In chapter two, we demonstrate how continuous flow technology can be exploited to develop synthetic processes towards prilocaine as our first case study. This chapter clearly demonstrates how highly exothermic nitration reactions can be safely handled by using continuous flow systems. Additionally, the use of a micro structured mixer facilitated biphasic nitration of toluene to be carried out with enhanced mass transfer, which inherently led to improved selectivity of ortho-nitrotoluene (preferred isomer) to 79 % compared to 59 % achieved in batch mode. A two-step synthesis of ortho-toluidine via biphasic nitration of toluene and nitroreduction was demonstrated with the incorporation of a Zaiput liquid/liquid separator to facilitate in-line separation. Comprehensive optimisation studies were carried out in flow. Prilocaine was synthesised in 74 % overall yield in a 13.6 min residence time for all processes. In chapter three, we demonstrate how continuous flow technology can be exploited to develop synthetic processes towards betrixaban. Synthetic routes towards betrixaban feature two amide bond formation transformations. Pleasingly, we explored multistep chemistry to develop amide synthesis protocols in flow without interruption for work up and isolation. An overall yield of 92 % was achieved to get to key intermediate to betrixaban in 8 min total residence time. Chapter four demonstrates the robustness of developed amide synthesis protocols, a key transformation in synthetic routes towards prilocaine and betrixaban in continuous flow systems. A total of 22 amides were synthesised via flow multistep processes with isolated yields greater than 82 %. All the compounds were characterized using infrared spectroscopy (IR), and nuclear magnetic resonance (NMR). Quantification of the reaction mixtures were carried out using highperformance liquid chromatography (HPLC) and gas chromatography (GC). , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Sagandira, Mellisa Brenda
- Date: 2024-12
- Subjects: Pharmaceutical technology , Drug development , Pharmaceutical biotechnology
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69464 , vital:77259
- Description: The dilemma of providing affordable health care has long haunted African countries due to the continuously growing disease burden as the population increases. Africa accounts for only 3 % of global drug production and imports over 90 % of its life saving medicines at a yearly cost of US$14 billion according to the African Development Bank (AfDB). Attaining Africa’s Agenda 2063, Universal Health Coverage (UHC) and Sustainable development Goal 3 (SDG3) aspirations of ensuring healthy and well-nourished citizens remain difficult given this situation. This over-dependence on imports has led to drug shortages, high pricing, poor quality medicines and unguaranteed supply chains, thus there still remains an unmet need. The advent of the COVID-19 pandemic worsened this situation as many countries curbed exports resulting in a crisis across the continent. Africa experienced high demand of medicines compared to prepandemic level, which threatened the health care of the continent. This situation can be addressed by establishment of local pharmaceutical manufacturing capability through adoption of advanced manufacturing technologies such as continuous flow chemistry. In this research, we therefore seek to exploit continuous flow chemistry, an enabling technology to develop safe and efficient synthetic processes for active pharmaceutical ingredients: prilocaine and betrixaban as case studies. To the best of our knowledge there is no reported work on synthetic processes towards prilocaine and betrixaban under continuous flow conditions, thus this research extensively unearthed interesting continuous flow processes towards these APIs. In a broader view, establishment of local APIs production will ease Africa’s over-dependence on imports, which will in turn address issues such as drug shortages, poor quality and high pricing. This work aims to demonstrate how continuous flow technology can be useful for the establishment of local APIs manufacturing, which will inherently revolutionize medicines availability, affordability and accessibility to the greater population. Chapter one begins with a brief overview on Africa’s disease burden and pharmaceutical supply chain. Continuous flow chemistry is introduced with its benefits and limitations discussed. Lastly a mini review of examples of APIs synthesised in continuous flow is presented. In chapter two, we demonstrate how continuous flow technology can be exploited to develop synthetic processes towards prilocaine as our first case study. This chapter clearly demonstrates how highly exothermic nitration reactions can be safely handled by using continuous flow systems. Additionally, the use of a micro structured mixer facilitated biphasic nitration of toluene to be carried out with enhanced mass transfer, which inherently led to improved selectivity of ortho-nitrotoluene (preferred isomer) to 79 % compared to 59 % achieved in batch mode. A two-step synthesis of ortho-toluidine via biphasic nitration of toluene and nitroreduction was demonstrated with the incorporation of a Zaiput liquid/liquid separator to facilitate in-line separation. Comprehensive optimisation studies were carried out in flow. Prilocaine was synthesised in 74 % overall yield in a 13.6 min residence time for all processes. In chapter three, we demonstrate how continuous flow technology can be exploited to develop synthetic processes towards betrixaban. Synthetic routes towards betrixaban feature two amide bond formation transformations. Pleasingly, we explored multistep chemistry to develop amide synthesis protocols in flow without interruption for work up and isolation. An overall yield of 92 % was achieved to get to key intermediate to betrixaban in 8 min total residence time. Chapter four demonstrates the robustness of developed amide synthesis protocols, a key transformation in synthetic routes towards prilocaine and betrixaban in continuous flow systems. A total of 22 amides were synthesised via flow multistep processes with isolated yields greater than 82 %. All the compounds were characterized using infrared spectroscopy (IR), and nuclear magnetic resonance (NMR). Quantification of the reaction mixtures were carried out using highperformance liquid chromatography (HPLC) and gas chromatography (GC). , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Exploring children’s understandings of gender using critical literacy in a reading club
- Jansen, Lincoln Lee, Surname, name
- Authors: Jansen, Lincoln Lee , Surname, name
- Date: 2024-12
- Subjects: Book clubs (Discussion groups) -- South Africa , Literacy -- Study and teaching (Elementary) , Literacy -- Study and teaching (Middle school)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68333 , vital:76976
- Description: School literacy practices have always favoured traditional, gender stereotypical portrayals of characters in books. These portrayals are not troublesome as it helps children build a sense of identity. However, these portrayals often fail to represent people in more diverse ways and thus does not reflect how societies have progressed. These narrow portrayals are also often limiting and do not take into consideration people’s personal interests which can lead to them being ostracised and marginalised. The People’s Republic of China is the context for this study where traditional, conservative views are upheld about ways of being and doing for males and females. This is a qualitative study within the interpretivist paradigm which recognised the individual perceptions of participants within their specific sociocultural context. By establishing a reading club as a Third Space for literacy engagement, this study sought to explore how grade 2 learners at a school in Beijing, China responded to traditional and diverse portrayals of characters in books. This study regarded the establishment of a reading club as an empowering practice as it allowed a safe space for the participants to freely share their deliberations about ways of being in the world. Coupled with critical literacy as a practice, participants took a critical stance in instances of gender bias and injustices and in doing so, allowed them to accentuate their morality. Findings of this study suggest that the Chinese participants had very flexible ideas about ways of being and doing in the world as long as these did not conflict with their understandings of the law. Participants also upheld that gender performances and gendered behaviour are open to all with impunity. The findings of this study also highlight the importance of providing diverse literature to children as this helps them to deal with, and examine, issues they might not ordinarily encounter in a safe way and in doing so, expand their worldviews and cultivate empathy. , Thesis (PhD) -- Faculty of Education, School of Primary Schooling, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Jansen, Lincoln Lee , Surname, name
- Date: 2024-12
- Subjects: Book clubs (Discussion groups) -- South Africa , Literacy -- Study and teaching (Elementary) , Literacy -- Study and teaching (Middle school)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68333 , vital:76976
- Description: School literacy practices have always favoured traditional, gender stereotypical portrayals of characters in books. These portrayals are not troublesome as it helps children build a sense of identity. However, these portrayals often fail to represent people in more diverse ways and thus does not reflect how societies have progressed. These narrow portrayals are also often limiting and do not take into consideration people’s personal interests which can lead to them being ostracised and marginalised. The People’s Republic of China is the context for this study where traditional, conservative views are upheld about ways of being and doing for males and females. This is a qualitative study within the interpretivist paradigm which recognised the individual perceptions of participants within their specific sociocultural context. By establishing a reading club as a Third Space for literacy engagement, this study sought to explore how grade 2 learners at a school in Beijing, China responded to traditional and diverse portrayals of characters in books. This study regarded the establishment of a reading club as an empowering practice as it allowed a safe space for the participants to freely share their deliberations about ways of being in the world. Coupled with critical literacy as a practice, participants took a critical stance in instances of gender bias and injustices and in doing so, allowed them to accentuate their morality. Findings of this study suggest that the Chinese participants had very flexible ideas about ways of being and doing in the world as long as these did not conflict with their understandings of the law. Participants also upheld that gender performances and gendered behaviour are open to all with impunity. The findings of this study also highlight the importance of providing diverse literature to children as this helps them to deal with, and examine, issues they might not ordinarily encounter in a safe way and in doing so, expand their worldviews and cultivate empathy. , Thesis (PhD) -- Faculty of Education, School of Primary Schooling, 2024
- Full Text:
- Date Issued: 2024-12
Gymnopilus junonius and Rhodofomitopsis lilacinogilva: In vitro evaluation of antimycobacterial activity, safety assessment and isolation of active compounds
- Authors: Didloff, Jenske
- Date: 2024-12
- Subjects: Antibacterial agents , Plants, Useful -- South Africa , Medicinal plants -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68840 , vital:77122
- Description: Tuberculosis remains a significant public health challenge due to the complexity and compliance issues of its treatment, the prevalence of latent infections, the high rate of HIV co-infection, and the spread of drug-resistant strains. This highlights the need to search for new antimycobacterial drugs. Natural products have historically been used as sources for the discovery of pharmaceuticals. Although medicinal macrofungi have been exploited in traditional folk medicines for the treatment of various diseases, research into their antimycobacterial activity remains limited.The aim of this study was to isolate, identify, and characterise the antimycobacterial compound(s) present in ethanol fruiting body extracts of Gymnopilus junonius (Fr.) P.D. Orton (Hymenogastraceae) and Rhodofomitopsis lilacinogilva (Berk.) B.K. Cui, M.L. Han, & Y.C. Dai (Fomitopsidaceae), as well as to investigate their mechanism of action and potential toxicity using in vitro and in vivo screening methods.Bioassay-guided fractionation was conducted using column chromatography and preparative thin-layer chromatography to isolate the active antimycobacterial fraction/compound from ethanol extracts of G. junonius and R. lilacinogilva. Antimycobacterial activity against M. tuberculosis H37Rv was screened using a resazurin microplate assay (REMA). The chemical structure was elucidated employing 1D-(1H NMR) and 2D NMR spectroscopy (HSQC, HMBC) techniques, along with High- Performance Liquid Chromatography High-Resolution Electron Spray Ionisation Mass Spectrometry (HPLC-HRESI-MS). Transmission electron microscopy (TEM) was utilised to observe the ultrastructural changes in M. tuberculosis induced by the active fraction/compound. Toxicity assessment was performed on African green monkeykidney (Vero) and human hepatoma (C3A) cell lines using various staining techniques to observe the potential risk for hepatotoxicity (CellRox orange, TMRE, and MTG staining) and genotoxicity (NucRed staining). In vivo toxicity of extracts was evaluated using a zebrafish embryo/larvae model to observe developmental and teratogenic effects.The bioassay-guided fractionation of G. junonius and R. lilacinogilva extracts yielded an active compound and a fraction displaying inhibitory activity against M. tuberculosis, with MIC values of 31.25 μg/mL and 250 μg/mL, respectively. Gymnopilene was identified as the main active compound isolated from G. junonius, while fraction 8 from R. lilacinogilva contained a predominant constituent resembling a pachymic acid derivative. Transmission electron microscopy revealed ultrastructural damage to M. tuberculosis cells upon treatment with gymnopilene and fraction 8, which was observed as the disruption and disintegration of the cell wall. In vitro toxicity assessment indicated a reduction in the cell density in both Vero and C3A cell lines following exposure to the fractions/gymnopilene. Although there were no significant alterations in the production of reactive oxygen species, changes in mitochondrial dynamics were observed. Genotoxic assessment showed no significant changes. In vivo toxicity assessment showed no significant effects for G. junonius against the zebrafish embryos/larvae, whereas R. lilacinogilva remained toxic and induced developmental abnormalities over a 72-hour time period.The findings of this study highlight the potential of macrofungi as a valuable source of bioactive compounds, confirming the significance of natural products in drug discovery. Notably, this research represents the first to demonstrate that the predominant compound, gymnopilene, isolated from G. junonius exhibits inhibitory activity against M. tuberculosis, contributing to the novelty of the study. Furthermore, the study expands our understanding of the antimycobacterial properties of the selected macrofungal species, G. junonius and R. lilacinogilva, by demonstrating the ultrastructural damage to M. tuberculosis cell wall induced by treatment. However, it is important to recognise the potential toxicity identified through in vitro and/or in vivo screening assays. The observed toxicity may hamper their suitability formdrug development. Future investigations could explore the inclusion of additional in vitro based models, perhaps more complex and physiologically relevant models alongside the in vivo screening model to assess the therapeutic potential of isolated fractions/compounds. , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Didloff, Jenske
- Date: 2024-12
- Subjects: Antibacterial agents , Plants, Useful -- South Africa , Medicinal plants -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68840 , vital:77122
- Description: Tuberculosis remains a significant public health challenge due to the complexity and compliance issues of its treatment, the prevalence of latent infections, the high rate of HIV co-infection, and the spread of drug-resistant strains. This highlights the need to search for new antimycobacterial drugs. Natural products have historically been used as sources for the discovery of pharmaceuticals. Although medicinal macrofungi have been exploited in traditional folk medicines for the treatment of various diseases, research into their antimycobacterial activity remains limited.The aim of this study was to isolate, identify, and characterise the antimycobacterial compound(s) present in ethanol fruiting body extracts of Gymnopilus junonius (Fr.) P.D. Orton (Hymenogastraceae) and Rhodofomitopsis lilacinogilva (Berk.) B.K. Cui, M.L. Han, & Y.C. Dai (Fomitopsidaceae), as well as to investigate their mechanism of action and potential toxicity using in vitro and in vivo screening methods.Bioassay-guided fractionation was conducted using column chromatography and preparative thin-layer chromatography to isolate the active antimycobacterial fraction/compound from ethanol extracts of G. junonius and R. lilacinogilva. Antimycobacterial activity against M. tuberculosis H37Rv was screened using a resazurin microplate assay (REMA). The chemical structure was elucidated employing 1D-(1H NMR) and 2D NMR spectroscopy (HSQC, HMBC) techniques, along with High- Performance Liquid Chromatography High-Resolution Electron Spray Ionisation Mass Spectrometry (HPLC-HRESI-MS). Transmission electron microscopy (TEM) was utilised to observe the ultrastructural changes in M. tuberculosis induced by the active fraction/compound. Toxicity assessment was performed on African green monkeykidney (Vero) and human hepatoma (C3A) cell lines using various staining techniques to observe the potential risk for hepatotoxicity (CellRox orange, TMRE, and MTG staining) and genotoxicity (NucRed staining). In vivo toxicity of extracts was evaluated using a zebrafish embryo/larvae model to observe developmental and teratogenic effects.The bioassay-guided fractionation of G. junonius and R. lilacinogilva extracts yielded an active compound and a fraction displaying inhibitory activity against M. tuberculosis, with MIC values of 31.25 μg/mL and 250 μg/mL, respectively. Gymnopilene was identified as the main active compound isolated from G. junonius, while fraction 8 from R. lilacinogilva contained a predominant constituent resembling a pachymic acid derivative. Transmission electron microscopy revealed ultrastructural damage to M. tuberculosis cells upon treatment with gymnopilene and fraction 8, which was observed as the disruption and disintegration of the cell wall. In vitro toxicity assessment indicated a reduction in the cell density in both Vero and C3A cell lines following exposure to the fractions/gymnopilene. Although there were no significant alterations in the production of reactive oxygen species, changes in mitochondrial dynamics were observed. Genotoxic assessment showed no significant changes. In vivo toxicity assessment showed no significant effects for G. junonius against the zebrafish embryos/larvae, whereas R. lilacinogilva remained toxic and induced developmental abnormalities over a 72-hour time period.The findings of this study highlight the potential of macrofungi as a valuable source of bioactive compounds, confirming the significance of natural products in drug discovery. Notably, this research represents the first to demonstrate that the predominant compound, gymnopilene, isolated from G. junonius exhibits inhibitory activity against M. tuberculosis, contributing to the novelty of the study. Furthermore, the study expands our understanding of the antimycobacterial properties of the selected macrofungal species, G. junonius and R. lilacinogilva, by demonstrating the ultrastructural damage to M. tuberculosis cell wall induced by treatment. However, it is important to recognise the potential toxicity identified through in vitro and/or in vivo screening assays. The observed toxicity may hamper their suitability formdrug development. Future investigations could explore the inclusion of additional in vitro based models, perhaps more complex and physiologically relevant models alongside the in vivo screening model to assess the therapeutic potential of isolated fractions/compounds. , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Prevalence and correlates of sickness presenteeism among secondary school teachers in the Bukedi region of eastern Uganda
- Authors: Majwala,Henry
- Date: 2024-12
- Subjects: Employees -- Mental health , Psychology, Industrial , Industrial psychiatry
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68355 , vital:76989
- Description: Education is regarded as one of the main cornerstones for sustainable development, especially if the majority of the global citizenry manage to achieve it at secondary school level. The efficaciousness thereof, however, almost entirely depends on the productivity and performance of teachers meant to instill various skill sets among secondary school learners. Sickness presenteeism among secondary school teachers has previously emerged and gained attention as the single most important antagonist of secondary school productivity. However, it has been reported to be increasing in magnitude as absenteeism has gradually decreased over the years. The aim of the study was to establish the prevalence and correlates of sickness presenteeism among secondary school teachers in the Bukedi region in Eastern Uganda. The study adopted a pragmatic philosophy and a sequential explanatory mixed methods design targeting 433 secondary school teachers in the Bukedi sub region of Eastern Uganda. The schools were stratified by district first and then each district was stratified by ownership. Simple random sampling was used to sample half the number of schools per stratum, simple random sampling was used to sample the teachers. Key informants such as principals and teachers were purposively sampled and engaged in key informant semi-structured interviews. Quantitative data emerging from an analysis of the questionnaires was analyzed in SPSS version 25 using the log-binomial model, while the qualitative data from the semi-structured interviews was analyzed thematically. This study disclosed that the majority (68.3%) of the teachers engaged in sickness presenteeism. Moon lighting, egocentrism and heavy workload were the significant intrapersonal correlates of sickness presenteeism, while under staffing was a prominent institutional correlate. This study confirms findings from global research that staff working in people-based service sectors are most likely to engage in sickness presenteeism. The recommendations include the following: MoES to formulate a comprehensive policy on sickness presenteeism for teachers, DEOs to make follow ups to address the prevalent sickness presenteeism among secondary school teachers, the school administration to set up a special committee dealing with teachers’ welfare regarding ill health and work, and teachers are to be educated, sensitized about the dangers associated with sickness presenteeism and how to handle it with the school administration. , Thesis (DPhil) -- Faculty of Education, School of Post Schooling, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Majwala,Henry
- Date: 2024-12
- Subjects: Employees -- Mental health , Psychology, Industrial , Industrial psychiatry
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68355 , vital:76989
- Description: Education is regarded as one of the main cornerstones for sustainable development, especially if the majority of the global citizenry manage to achieve it at secondary school level. The efficaciousness thereof, however, almost entirely depends on the productivity and performance of teachers meant to instill various skill sets among secondary school learners. Sickness presenteeism among secondary school teachers has previously emerged and gained attention as the single most important antagonist of secondary school productivity. However, it has been reported to be increasing in magnitude as absenteeism has gradually decreased over the years. The aim of the study was to establish the prevalence and correlates of sickness presenteeism among secondary school teachers in the Bukedi region in Eastern Uganda. The study adopted a pragmatic philosophy and a sequential explanatory mixed methods design targeting 433 secondary school teachers in the Bukedi sub region of Eastern Uganda. The schools were stratified by district first and then each district was stratified by ownership. Simple random sampling was used to sample half the number of schools per stratum, simple random sampling was used to sample the teachers. Key informants such as principals and teachers were purposively sampled and engaged in key informant semi-structured interviews. Quantitative data emerging from an analysis of the questionnaires was analyzed in SPSS version 25 using the log-binomial model, while the qualitative data from the semi-structured interviews was analyzed thematically. This study disclosed that the majority (68.3%) of the teachers engaged in sickness presenteeism. Moon lighting, egocentrism and heavy workload were the significant intrapersonal correlates of sickness presenteeism, while under staffing was a prominent institutional correlate. This study confirms findings from global research that staff working in people-based service sectors are most likely to engage in sickness presenteeism. The recommendations include the following: MoES to formulate a comprehensive policy on sickness presenteeism for teachers, DEOs to make follow ups to address the prevalent sickness presenteeism among secondary school teachers, the school administration to set up a special committee dealing with teachers’ welfare regarding ill health and work, and teachers are to be educated, sensitized about the dangers associated with sickness presenteeism and how to handle it with the school administration. , Thesis (DPhil) -- Faculty of Education, School of Post Schooling, 2024
- Full Text:
- Date Issued: 2024-12
Social dynamics of spotted hyaenas (Crocuta crocuta) in fenced protected areas: Implications for conservation management of a socially intelligent species
- Authors: Honiball, Terry-Lee
- Date: 2024-12
- Subjects: Spotted hyena -- Behavior -- South Africa , Wildlife conservation -- South Africa , Wildlife management -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68884 , vital:77159
- Description: It is important to understand the impact of fenced protected area management on the behaviour and fitness of less popular species, such as the spotted hyeana (Crocuta crocuta), that have been historically overlooked in species management across protected areas. As a result of this oversight, hyaena population densities have reached high levels, making it critical to study the effects of fenced protected area management on these species. There is a lack of understanding of how species adapt to the potentially high-pressure systems (through the restriction of resources spatially) created by fenced protected areas and the intrinsic effects that management regimes may have on wildlife. Due to the spotted hyaena’s high behavioural plasticity, they make excellent candidates to explore the effects of management regimes in fenced protected areas while enhancing our understanding of spotted hyaena ecology. Therefore, the aim of this study was to explore the ecology and social behaviour of high density spotted hyaena populations in fenced protected areas to understand the effects of different management regimes and how spotted hyaenas respond to these differing pressures. This was achieved through four main objectives which consider different aspects of spotted hyaena ecology and the influence of management regimes and environmental variables in two fenced protected areas in South Africa; Madikwe Game Reserve (a socio-economically incentivised reserve) and Addo Elephant National Park (a reserve incentivised by the promotion of biodiversity), between 2021 and 2023. This study explored 1) range residency patterns and third order habitat selection in spotted hyaena movement, 2) interspecific interactions at shared food sources to understand the role of lion, Panthera leo, and spotted hyaenas dynamics in top-down pressure in carnivore structure, 3) territorial interactions when defending resources to understand spotted hyaena social dominance when occurring at high densities, 4) welfare considerations and allostatic load of spotted hyaenas, and additionally we provided insight into the social hierarchy disruptions which occur when removing the matriarch from a clan through an opportunistic record. By assessing the effects of socio-economic or biodiversity driven management regimes, this study provided novel accounts of social behaviour and responses of spotted hyaenas to pressures in fenced protected areas, highlighting the top-down pressure that lions have on multiple aspects of spotted hyaena functioning. Road networks and infrastructure in fenced protected areas were generally utilised by spotted hyaenas and despite high abundance, prey availability remained an important aspect of spotted hyaena ecology regardless of management regimes. Further, we showed that when food is abundant, spotted hyaenas are tolerant of subordinate carnivores, which emphasises their dynamic behavioural plasticity. We showed that spotted hyaenas gauge territorial responses according to the perceived threat and are less tolerant to familiar intruders than to unfamiliar individuals, which is an important inbreeding avoidance tactic that remains in place in fenced protected areas. And lastly, we showed that management regimes influence the adrenal function of spotted hyaenas, where fenced protected areas incentivised by wildlife photographic tourism may negatively affect species fitness through elevated epidandrosterone levels over time. However, spotted hyaenas appear to have adapted to elevated hormone levels, thus not affecting fecundity in fenced protected areas, resulting in high density populations. This study provides a holistic overview of the effects of management regimes on spotted hyaenas in fenced protected areas and provides insights into how spotted hyaenas adapt to pressures when occurring at high densities in these areas. This study contributes to the understanding of spotted hyaena ecology and the intrinsic effects on wildlife of different approaches to management regimes in fenced protected areas. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Honiball, Terry-Lee
- Date: 2024-12
- Subjects: Spotted hyena -- Behavior -- South Africa , Wildlife conservation -- South Africa , Wildlife management -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68884 , vital:77159
- Description: It is important to understand the impact of fenced protected area management on the behaviour and fitness of less popular species, such as the spotted hyeana (Crocuta crocuta), that have been historically overlooked in species management across protected areas. As a result of this oversight, hyaena population densities have reached high levels, making it critical to study the effects of fenced protected area management on these species. There is a lack of understanding of how species adapt to the potentially high-pressure systems (through the restriction of resources spatially) created by fenced protected areas and the intrinsic effects that management regimes may have on wildlife. Due to the spotted hyaena’s high behavioural plasticity, they make excellent candidates to explore the effects of management regimes in fenced protected areas while enhancing our understanding of spotted hyaena ecology. Therefore, the aim of this study was to explore the ecology and social behaviour of high density spotted hyaena populations in fenced protected areas to understand the effects of different management regimes and how spotted hyaenas respond to these differing pressures. This was achieved through four main objectives which consider different aspects of spotted hyaena ecology and the influence of management regimes and environmental variables in two fenced protected areas in South Africa; Madikwe Game Reserve (a socio-economically incentivised reserve) and Addo Elephant National Park (a reserve incentivised by the promotion of biodiversity), between 2021 and 2023. This study explored 1) range residency patterns and third order habitat selection in spotted hyaena movement, 2) interspecific interactions at shared food sources to understand the role of lion, Panthera leo, and spotted hyaenas dynamics in top-down pressure in carnivore structure, 3) territorial interactions when defending resources to understand spotted hyaena social dominance when occurring at high densities, 4) welfare considerations and allostatic load of spotted hyaenas, and additionally we provided insight into the social hierarchy disruptions which occur when removing the matriarch from a clan through an opportunistic record. By assessing the effects of socio-economic or biodiversity driven management regimes, this study provided novel accounts of social behaviour and responses of spotted hyaenas to pressures in fenced protected areas, highlighting the top-down pressure that lions have on multiple aspects of spotted hyaena functioning. Road networks and infrastructure in fenced protected areas were generally utilised by spotted hyaenas and despite high abundance, prey availability remained an important aspect of spotted hyaena ecology regardless of management regimes. Further, we showed that when food is abundant, spotted hyaenas are tolerant of subordinate carnivores, which emphasises their dynamic behavioural plasticity. We showed that spotted hyaenas gauge territorial responses according to the perceived threat and are less tolerant to familiar intruders than to unfamiliar individuals, which is an important inbreeding avoidance tactic that remains in place in fenced protected areas. And lastly, we showed that management regimes influence the adrenal function of spotted hyaenas, where fenced protected areas incentivised by wildlife photographic tourism may negatively affect species fitness through elevated epidandrosterone levels over time. However, spotted hyaenas appear to have adapted to elevated hormone levels, thus not affecting fecundity in fenced protected areas, resulting in high density populations. This study provides a holistic overview of the effects of management regimes on spotted hyaenas in fenced protected areas and provides insights into how spotted hyaenas adapt to pressures when occurring at high densities in these areas. This study contributes to the understanding of spotted hyaena ecology and the intrinsic effects on wildlife of different approaches to management regimes in fenced protected areas. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-12
The lived experiences of final-year undergraduate diagnostic radiography students applying radiation protection measures during clinical practice
- Authors: Campbell, Sydney Samuel
- Date: 2024-12
- Subjects: Radiographers , College students -- South Africa , Experiential learning
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68311 , vital:76973
- Description: Radiographers use ionising radiation to produce radiographic images and the use of ionising radiation in healthcare has both benefits and risks for patients and healthcare professionals. It is therefore important that radiographers mitigate the risks associated with ionising radiation. It is for this reason that radiation protection measures are applied to ensure the safety of patients, staff, and the public. Furthermore, radiographers are also responsible for mentoring radiography students and inculcate the use of radiation protection measures when students undergo their workplace learning. This mentoring takes place in the clinical setting with its characteristics that may or may not advance the application of radiation protection measures. The aim of this study was to investigate the lived experiences of final-year undergraduate radiography students applying radiation protection measures in the clinical setting and to propose strategies to foster the integration of radiation protection theory into clinical practice. This study was located in the interpretivist paradigm using phenomenology as a research method and theoretical framework to achieve the stated aim. The target population for this qualitative study included all registered final-year undergraduate radiography students at the local university who perform their WPL at the accredited training hospitals in the Eastern Cape Province as this cohort of students have more clinical experience than the first-, second- and third-year students. The target population comprised 28 students. Purposive sampling was employed to select the group of radiography students to interview. The study used phenomenological interviews as a data collection tool and the collected data was explicated using a self-developed method. The trustworthiness of the study was ensured by applying Guba’s model of trustworthiness that includes credibility, transferability, confirmability, dependability and authenticity and was further enhanced by reflecting on the balanced integration, openness, concreteness, and resonance of the study. This study employed an ethical framework referred to as principlism that includes the notions of autonomy, beneficence, non-maleficence and justice.Data explication was conducted using three cycles of explication. Cycle one produced interpretive profiles for each participant. The interpretive profiles revealed the life histories of each participant as well as the utterances of participants related to the three sub-questions. Cycle two produced four themes. Theme one described participants’ being with others such as radiographers, clinical supervisors, medical doctors, and patients and revealed the tension between participants’ belonging and being unwanted. Theme two characterised the clinical setting as a place where several factors flow together to provide participants with their individualised experiences. Theme two revealed the emotional distress; the learning through trial-and-error; the independent learning; learning that is coupled with humiliation as experienced by participants. The clinical space was also characterised as a place to be survived, a place where students have to be inconspicuous and understand the acceptable levels of engagement with others. It is also a place where theory and practice at times is in alignment at other times not in alignment. The clinical setting could also be a place of self-doubt and insecurity, a place of personal growth, and a place where historical events are significant. Theme three disclosed the unspoken lessons that were conveyed through the actions and behaviours of individuals in the clinical environment. Unintended lesson one is that radiation protection measures are not important. Lesson two suggest that classroom teaching about radiation protection is not valid in the clinical setting, and finally that incivility towards radiography students is acceptable. Theme four revealed the difficulties experienced by radiography students when navigating ethical dilemmas. The theme revealed radiographers’ and radiologists’ indifference towards radiation protection, the non-application of radiation protection measures, and the inconsistency and apathy towards radiation protection measures. Cycle three viewed the experiences of participants through the lens of Dasein’s disclosedness. This revealed the exclusive language used by participants, the largely negative mood and participants’ disconnection from the imaging department.Finally, the study presented new and important insights by probing the topic of radiation protection in a novel way by using phenomenology to focus on the lived experiences of final-year undergraduate students applying radiation protection measures in the clinical setting. The findings of the study also allowed for the development of Enhancement strategies that could be used by institutions of higher education to promote the integration of the theory and practice of radiation protection measures in the clinical setting. It is recommended, though, that a study that includes all South African institutions of higher learning offering radiography be conducted using phenomenology. Furthermore, the views of South African radiographers and clinical supervisors should also be elicited to corroborate the views of participants in this study. , Thesis (PhD) -- Faculty of Education, School of Secondary Education, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Campbell, Sydney Samuel
- Date: 2024-12
- Subjects: Radiographers , College students -- South Africa , Experiential learning
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68311 , vital:76973
- Description: Radiographers use ionising radiation to produce radiographic images and the use of ionising radiation in healthcare has both benefits and risks for patients and healthcare professionals. It is therefore important that radiographers mitigate the risks associated with ionising radiation. It is for this reason that radiation protection measures are applied to ensure the safety of patients, staff, and the public. Furthermore, radiographers are also responsible for mentoring radiography students and inculcate the use of radiation protection measures when students undergo their workplace learning. This mentoring takes place in the clinical setting with its characteristics that may or may not advance the application of radiation protection measures. The aim of this study was to investigate the lived experiences of final-year undergraduate radiography students applying radiation protection measures in the clinical setting and to propose strategies to foster the integration of radiation protection theory into clinical practice. This study was located in the interpretivist paradigm using phenomenology as a research method and theoretical framework to achieve the stated aim. The target population for this qualitative study included all registered final-year undergraduate radiography students at the local university who perform their WPL at the accredited training hospitals in the Eastern Cape Province as this cohort of students have more clinical experience than the first-, second- and third-year students. The target population comprised 28 students. Purposive sampling was employed to select the group of radiography students to interview. The study used phenomenological interviews as a data collection tool and the collected data was explicated using a self-developed method. The trustworthiness of the study was ensured by applying Guba’s model of trustworthiness that includes credibility, transferability, confirmability, dependability and authenticity and was further enhanced by reflecting on the balanced integration, openness, concreteness, and resonance of the study. This study employed an ethical framework referred to as principlism that includes the notions of autonomy, beneficence, non-maleficence and justice.Data explication was conducted using three cycles of explication. Cycle one produced interpretive profiles for each participant. The interpretive profiles revealed the life histories of each participant as well as the utterances of participants related to the three sub-questions. Cycle two produced four themes. Theme one described participants’ being with others such as radiographers, clinical supervisors, medical doctors, and patients and revealed the tension between participants’ belonging and being unwanted. Theme two characterised the clinical setting as a place where several factors flow together to provide participants with their individualised experiences. Theme two revealed the emotional distress; the learning through trial-and-error; the independent learning; learning that is coupled with humiliation as experienced by participants. The clinical space was also characterised as a place to be survived, a place where students have to be inconspicuous and understand the acceptable levels of engagement with others. It is also a place where theory and practice at times is in alignment at other times not in alignment. The clinical setting could also be a place of self-doubt and insecurity, a place of personal growth, and a place where historical events are significant. Theme three disclosed the unspoken lessons that were conveyed through the actions and behaviours of individuals in the clinical environment. Unintended lesson one is that radiation protection measures are not important. Lesson two suggest that classroom teaching about radiation protection is not valid in the clinical setting, and finally that incivility towards radiography students is acceptable. Theme four revealed the difficulties experienced by radiography students when navigating ethical dilemmas. The theme revealed radiographers’ and radiologists’ indifference towards radiation protection, the non-application of radiation protection measures, and the inconsistency and apathy towards radiation protection measures. Cycle three viewed the experiences of participants through the lens of Dasein’s disclosedness. This revealed the exclusive language used by participants, the largely negative mood and participants’ disconnection from the imaging department.Finally, the study presented new and important insights by probing the topic of radiation protection in a novel way by using phenomenology to focus on the lived experiences of final-year undergraduate students applying radiation protection measures in the clinical setting. The findings of the study also allowed for the development of Enhancement strategies that could be used by institutions of higher education to promote the integration of the theory and practice of radiation protection measures in the clinical setting. It is recommended, though, that a study that includes all South African institutions of higher learning offering radiography be conducted using phenomenology. Furthermore, the views of South African radiographers and clinical supervisors should also be elicited to corroborate the views of participants in this study. , Thesis (PhD) -- Faculty of Education, School of Secondary Education, 2024
- Full Text:
- Date Issued: 2024-12
The optimisation of Eucalyptus regeneration practices for improved survival, growth and uniformity in South African pulpwood plantations
- Authors: Hechter, Ullrich
- Date: 2024-12
- Subjects: Eucalyptus -- Regeneration -- South Africa , Forests and forestry -- Economic aspects , Forests and forestry
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68862 , vital:77135
- Description: Commercial forestry plantations in South Africa play an important role in the economy of the country, contributing 1.2% towards the gross domestic product. Currently plantation forests occupy 1.1% (1.2 million hectares) of the South African land surface, of which 75 000 hectares are re-established each year. Eucalypts constitute 43% of planted area, of which 88% is grown for pulpwood. Achieving high tree survival (>90%) is important in terms of optimising rotation-end yield. The industry origin of a 90% survival benchmark is unclear, although company procedures incorporate this as the minimum threshold in terms of re-establishment success. Past research indicates that most mortality occurs within a narrow period post-establishment and is often associated with substandard re-establishment practices and/or a stressed micro-environment. An improved understanding is needed about the various mitigation measures needed to minimize mortality during eucalypt re-establishment. Before making decisions related to mortality mitigation measures, comprehensive data are required as to their commercial applicability as well as outcomes from multiple trials that accurately quantify any impacts on tree survival and financial return. The overall purpose of this dissertation was the optimisation of Eucalyptus re-establishment practices for improved survival, growth and uniformity in South African pulpwood plantations. To achieve this, five inter-linked objectives were determined. The first objective was to highlight the most important factors contributing to increased mortality in eucalypt plantations during re-establishment. This was achieved through conducting a literature review. Citations were ranked in terms of credibility, with the importance ratings (derived from the literature sources) applied to the different factors affecting survival and growth during eucalypt re-establishment. Of the various factors impacting early eucalypt mortality, water stress and planting stock quality were considered highly important. The manner and quality of site preparation (soil and slash), planting practices (planting depth included), timing of planting (during dry, hot periods), various post-planting operations (incorrect fertiliser placement or herbicide drift) and insect pests and diseases also contribute to mortality, but to a lesser extent. These factors cannot be considered in isolation due to the complex interactions that exist between them and determining the primary causes of mortality can be elusive, especially as their impacts tend to be additive by nature. The second objective was to link survival to silvicultural treatments, site-related physiographic factors and climatic variables in South Africa. This was achieved by conducting an integrated analysis of 43 Eucalyptus trials. Of the seven re-establishment practices considered, watering, planting depth and fertiliser application were significant, with plant size, pitting method, residue management and insecticide application were not significant. However, when environmental variables were included within the analyses, there were significant site x treatment interactions for planting depth, plant size, residue management and fertiliser application. This highlights the importance of taking site related factors into consideration when interpreting the causes of mortality. The third objective was to determine the interaction between planting density and mortality on Eucalyptus growth, uniformity and financial yield at rotation end in South Africa. This was carried out to verify whether planting at different densities may be used as a preventative (before planting) mitigation measure. One trial was used to answer four keys sub-objectives: 1) The impact of three planting densities (1 102, 1 500, 1 959 SPH) with no mortality on yield at rotation-end; 2) The impact of mortality (0%, 10%, 20%, 30%, 40%) on rotation-end yield; 3) The quantification of tree performance when planting at a higher density and accepting a certain degree of mortality; and 4) The financial impact of different planting densities and mortality on rotation-end profit. Higher planting densities resulted in smaller individual trees, but with an increase in stand level performance. At rotation-end, lower mortality (0% and 10%) had significantly higher volumes ha-1 than the higher mortality (30% and 40%). Planting at higher densities (1 722 and 1 959 SPH) and accepting a certain degree of mortality resulted in non-significant differences for volume at rotation-end compared to the fully stocked 1 500 SPH treatment. A higher SPH resulted in a higher yield, but with an increase in estimated establishment/tending and harvesting costs. In contrast, an increase in mortality and/or lower SPH (in the absence of mortality) resulted in more variable stand growth, together with an increase in estimated machine harvesting productivity and reduced costs. Irrespective of SPH, the higher the mortality the greater the loss of income, with the best profit within each treatment related to full stocking (0% mortality). Within the higher panting densities, the profit gained following low mortality (10 and 20%) was similar to that of no mortality (0%), indicating that higher mortality may be tolerated when planting at higher densities, confirming the 90% survival threshold the industry aims to achieve post-establishment. The fourth objective was to determine if silviculture intervention (blanking at 1, 2 and 3 months or coppicing and interplanting at 6 months) will result in acceptable eucalypt stocking, if mortality is higher than 10% (remedial mitigation measure). Data from a re-establishment trial were analysed to determine which of the mitigation measures performed best in terms of stocking and growth. Coppicing and interplanting with larger plants was not a viable option as a mitigation measure for mortality as most of the coppice shoots have died. This may have been a result of frost. Although high re-establishment costs may be incurred, disaster clearing to waste followed by replanting is an option if mortality is unacceptably high (as opposed to leaving the stand as is). The results of this objective confirm that blanking as the current Best Operating Practice is still appropriate in South African forestry (i.e., try to have survival >90% and blank as soon as possible to retain >90% of stems). Blanked plants do contribute to volume, but for this to occur, blanking should be carried out within 4 weeks after planting to gain maximum benefit. In addition, it highlights the importance of implementing remedial mitigation measures to achieve >90% survival so as to gain maximum benefit. Using the outcomes from objectives 1-4, the fifth objective focussed on the development of a decision support system (DSS) for implementation of mitigation measures to improve survival within commercial eucalypt pulpwood plantations in South Africa. Improved survival starts with the implementation of good re-establishment practices and good quality planting stock. Mitigation measures for poor survival can be implemented either prior to re-establishment (before mortality occurs) or post re-establishment (after mortality has occurred). If poor survival still occurs after the implementation of good silviculture practices and pre-re-establishment mitigation practices (planting at higher densities), one should consider the various options available in terms of post re-establishment mitigation practices (remedial practices) such as blanking or replanting if mortality is high. Overall, the outcomes from this dissertation provide benchmark data and derived information as to the necessity for various mortality mitigation options within the commercial forestry sector in South Africa. In addition, the DSS will assist with decision making in terms of implementing the best silviculture practices and mitigation measures for improved survival during eucalypt re-establishment in South African pulpwood plantations. , Thesis (PhD) -- Faculty of Science, School of Natural Resource Science & Management, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Hechter, Ullrich
- Date: 2024-12
- Subjects: Eucalyptus -- Regeneration -- South Africa , Forests and forestry -- Economic aspects , Forests and forestry
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68862 , vital:77135
- Description: Commercial forestry plantations in South Africa play an important role in the economy of the country, contributing 1.2% towards the gross domestic product. Currently plantation forests occupy 1.1% (1.2 million hectares) of the South African land surface, of which 75 000 hectares are re-established each year. Eucalypts constitute 43% of planted area, of which 88% is grown for pulpwood. Achieving high tree survival (>90%) is important in terms of optimising rotation-end yield. The industry origin of a 90% survival benchmark is unclear, although company procedures incorporate this as the minimum threshold in terms of re-establishment success. Past research indicates that most mortality occurs within a narrow period post-establishment and is often associated with substandard re-establishment practices and/or a stressed micro-environment. An improved understanding is needed about the various mitigation measures needed to minimize mortality during eucalypt re-establishment. Before making decisions related to mortality mitigation measures, comprehensive data are required as to their commercial applicability as well as outcomes from multiple trials that accurately quantify any impacts on tree survival and financial return. The overall purpose of this dissertation was the optimisation of Eucalyptus re-establishment practices for improved survival, growth and uniformity in South African pulpwood plantations. To achieve this, five inter-linked objectives were determined. The first objective was to highlight the most important factors contributing to increased mortality in eucalypt plantations during re-establishment. This was achieved through conducting a literature review. Citations were ranked in terms of credibility, with the importance ratings (derived from the literature sources) applied to the different factors affecting survival and growth during eucalypt re-establishment. Of the various factors impacting early eucalypt mortality, water stress and planting stock quality were considered highly important. The manner and quality of site preparation (soil and slash), planting practices (planting depth included), timing of planting (during dry, hot periods), various post-planting operations (incorrect fertiliser placement or herbicide drift) and insect pests and diseases also contribute to mortality, but to a lesser extent. These factors cannot be considered in isolation due to the complex interactions that exist between them and determining the primary causes of mortality can be elusive, especially as their impacts tend to be additive by nature. The second objective was to link survival to silvicultural treatments, site-related physiographic factors and climatic variables in South Africa. This was achieved by conducting an integrated analysis of 43 Eucalyptus trials. Of the seven re-establishment practices considered, watering, planting depth and fertiliser application were significant, with plant size, pitting method, residue management and insecticide application were not significant. However, when environmental variables were included within the analyses, there were significant site x treatment interactions for planting depth, plant size, residue management and fertiliser application. This highlights the importance of taking site related factors into consideration when interpreting the causes of mortality. The third objective was to determine the interaction between planting density and mortality on Eucalyptus growth, uniformity and financial yield at rotation end in South Africa. This was carried out to verify whether planting at different densities may be used as a preventative (before planting) mitigation measure. One trial was used to answer four keys sub-objectives: 1) The impact of three planting densities (1 102, 1 500, 1 959 SPH) with no mortality on yield at rotation-end; 2) The impact of mortality (0%, 10%, 20%, 30%, 40%) on rotation-end yield; 3) The quantification of tree performance when planting at a higher density and accepting a certain degree of mortality; and 4) The financial impact of different planting densities and mortality on rotation-end profit. Higher planting densities resulted in smaller individual trees, but with an increase in stand level performance. At rotation-end, lower mortality (0% and 10%) had significantly higher volumes ha-1 than the higher mortality (30% and 40%). Planting at higher densities (1 722 and 1 959 SPH) and accepting a certain degree of mortality resulted in non-significant differences for volume at rotation-end compared to the fully stocked 1 500 SPH treatment. A higher SPH resulted in a higher yield, but with an increase in estimated establishment/tending and harvesting costs. In contrast, an increase in mortality and/or lower SPH (in the absence of mortality) resulted in more variable stand growth, together with an increase in estimated machine harvesting productivity and reduced costs. Irrespective of SPH, the higher the mortality the greater the loss of income, with the best profit within each treatment related to full stocking (0% mortality). Within the higher panting densities, the profit gained following low mortality (10 and 20%) was similar to that of no mortality (0%), indicating that higher mortality may be tolerated when planting at higher densities, confirming the 90% survival threshold the industry aims to achieve post-establishment. The fourth objective was to determine if silviculture intervention (blanking at 1, 2 and 3 months or coppicing and interplanting at 6 months) will result in acceptable eucalypt stocking, if mortality is higher than 10% (remedial mitigation measure). Data from a re-establishment trial were analysed to determine which of the mitigation measures performed best in terms of stocking and growth. Coppicing and interplanting with larger plants was not a viable option as a mitigation measure for mortality as most of the coppice shoots have died. This may have been a result of frost. Although high re-establishment costs may be incurred, disaster clearing to waste followed by replanting is an option if mortality is unacceptably high (as opposed to leaving the stand as is). The results of this objective confirm that blanking as the current Best Operating Practice is still appropriate in South African forestry (i.e., try to have survival >90% and blank as soon as possible to retain >90% of stems). Blanked plants do contribute to volume, but for this to occur, blanking should be carried out within 4 weeks after planting to gain maximum benefit. In addition, it highlights the importance of implementing remedial mitigation measures to achieve >90% survival so as to gain maximum benefit. Using the outcomes from objectives 1-4, the fifth objective focussed on the development of a decision support system (DSS) for implementation of mitigation measures to improve survival within commercial eucalypt pulpwood plantations in South Africa. Improved survival starts with the implementation of good re-establishment practices and good quality planting stock. Mitigation measures for poor survival can be implemented either prior to re-establishment (before mortality occurs) or post re-establishment (after mortality has occurred). If poor survival still occurs after the implementation of good silviculture practices and pre-re-establishment mitigation practices (planting at higher densities), one should consider the various options available in terms of post re-establishment mitigation practices (remedial practices) such as blanking or replanting if mortality is high. Overall, the outcomes from this dissertation provide benchmark data and derived information as to the necessity for various mortality mitigation options within the commercial forestry sector in South Africa. In addition, the DSS will assist with decision making in terms of implementing the best silviculture practices and mitigation measures for improved survival during eucalypt re-establishment in South African pulpwood plantations. , Thesis (PhD) -- Faculty of Science, School of Natural Resource Science & Management, 2024
- Full Text:
- Date Issued: 2024-12
Toughened wood plastic composites for low technology and advanced manufacturing applications
- Authors: Mabutho, Briswell
- Date: 2024-12
- Subjects: Plastic-impregnated wood , Polymeric composites
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69360 , vital:77225
- Description: The utilization of wood plastic composites (WPCs) has increasingly emerged as an appealing alternative for products where traditional wood and conventional composites would typically be used. This is primarily due to their cost-effectiveness, mouldability, recyclability, renewability, and potential biodegradability. However, the incorporation of wood flour (WF) in thermoplastics to produce WPCs presents several challenges, two of which are addressed in the current study: the WF-thermoplastic matrix adhesion, and the resulting brittleness of the WPC. The hydrophilic nature of WF filler and the hydrophobic polypropylene matrix, which typically lead to poor mixing due to their differing surface energies. Consequently, the current research focuses on enhancing WF-matrix (i.e. polypropylene, PP) adhesion and dispersion through compatibilization using maleic anhydride grafted polypropylene (MAPP). Additionally, the brittleness of WPC, exacerbated by the WF content, is addressed through the incorporation of crumb rubber (CR), a process commonly referred to as "toughening" the WPC. Prior to the use of CR in WPCs, optimization of the CR amount and compatibility within the PP-matrix were conducted to establish a toughening system that would achieve the highest impact strength without significantly affecting the tensile strength. The CR was compatibilized by employing dynamic vulcanization of varying amounts of ethylene propylene diene monomer rubber (EPDM) in the CR/PP blends using both sulphur and dicumyl peroxide cure systems. The results indicated that the sulphur dynamic cure system exhibited higher crosslinking efficiency, as reflected by the highest impact strength. Furthermore, to enhance WPC processability and adhesion, WF alkalization was conducted following a central composite design to optimize treatment temperature, time, and alkali concentration. This optimization resulted in improved WPC processability and mechanical properties at mild alkalization conditions. Subsequently, the optimum CR/EPDM dynamic cure system was employed to toughen both untreated and alkalized WPCs, resulting in toughened WPCs with improved thermal stability, impact strength, and elongation at break, while the tensile strength was only slightly compromised. , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Mabutho, Briswell
- Date: 2024-12
- Subjects: Plastic-impregnated wood , Polymeric composites
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69360 , vital:77225
- Description: The utilization of wood plastic composites (WPCs) has increasingly emerged as an appealing alternative for products where traditional wood and conventional composites would typically be used. This is primarily due to their cost-effectiveness, mouldability, recyclability, renewability, and potential biodegradability. However, the incorporation of wood flour (WF) in thermoplastics to produce WPCs presents several challenges, two of which are addressed in the current study: the WF-thermoplastic matrix adhesion, and the resulting brittleness of the WPC. The hydrophilic nature of WF filler and the hydrophobic polypropylene matrix, which typically lead to poor mixing due to their differing surface energies. Consequently, the current research focuses on enhancing WF-matrix (i.e. polypropylene, PP) adhesion and dispersion through compatibilization using maleic anhydride grafted polypropylene (MAPP). Additionally, the brittleness of WPC, exacerbated by the WF content, is addressed through the incorporation of crumb rubber (CR), a process commonly referred to as "toughening" the WPC. Prior to the use of CR in WPCs, optimization of the CR amount and compatibility within the PP-matrix were conducted to establish a toughening system that would achieve the highest impact strength without significantly affecting the tensile strength. The CR was compatibilized by employing dynamic vulcanization of varying amounts of ethylene propylene diene monomer rubber (EPDM) in the CR/PP blends using both sulphur and dicumyl peroxide cure systems. The results indicated that the sulphur dynamic cure system exhibited higher crosslinking efficiency, as reflected by the highest impact strength. Furthermore, to enhance WPC processability and adhesion, WF alkalization was conducted following a central composite design to optimize treatment temperature, time, and alkali concentration. This optimization resulted in improved WPC processability and mechanical properties at mild alkalization conditions. Subsequently, the optimum CR/EPDM dynamic cure system was employed to toughen both untreated and alkalized WPCs, resulting in toughened WPCs with improved thermal stability, impact strength, and elongation at break, while the tensile strength was only slightly compromised. , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Vocational Education and the relentless struggles of TVET graduates in the Eastern Cape, South Africa: A Freirean approach
- Authors: Majola, Ezekiel
- Date: 2024-12
- Subjects: Vocational education -- Eastern Cape -- South Africa , Technical education -- Eastern Cape -- South Africa , School-to-work transition -- Eastern Cape -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/${Handle} , vital:76985
- Description: This study employs Paulo Freire’s framework to contribute to debates surrounding social justice and transformation in vocational education and training (TVET). By offering a critical perspective on dominant discourse and practices, it challenges prevailing trajectories of powerful knowledge and inherent assumptions and biases in TVET. Drawing on a Freirean framework, the research provides insights to develop more equitable and transformative practices by addressing power, privilege, and social inequality in TVET. Through dialogue and collaboration with students, it promotes critical consciousness and relevant skills and knowledge. Highlighting the significance of context, it underscores the need to understand the social and cultural context of learning. Demonstrating the potential of a Freirean framework to challenge the status quo, it promotes more equitable and empowering practices in TVET. The chosen methodology for this study is Participatory Action Research (PAR), integrating theory, action, and participation to address social issues. Recruiting 15 NC(V) graduates from Algoa TVET College, forming a Learning Cycle Group (LCG), the study aimed to comprehend graduates’ experiences, challenges, and opportunities. Life narrative interviews and LCG meetings generated data, ensuring every participant had a voice and strengthening group cohesion. Data were grounded in ethical values such as respect, equality, inclusion, democratic participation, active learning, making a difference, collective action, and personal integrity. Employing Paulo Freire’s theoretical framework, this study offers a novel perspective on TVET in South Africa, fostering dialogue with TVET students to challenge conventional discourses. It aimed to develop an alternative conceptualisation of TVET by incorporating student experiences and perspectives, promoting positive change through dialogue and addressing power dynamics and social justice issues. The study explores Powell’s (2014) question regarding TVET colleges’ role in expanding opportunities for students and asks: “How do TVET graduates experience life after graduation? Are they empowered and satisfied with their social status?” Sub-questions inquire about students’ expectations upon enrolling, opportunities after completing NC(V) programs, and the extent to which TVET colleges address unemployment and socio-economic injustices, aiming to inspire the development of praxis and frameworks that better serve the needs of TVET graduates and address social concerns.The study’s findings, analysed through Freire’s ideology in “We Make the Road by Walking” (1990) and “Pedagogy of Hope” (1994), reveal that the NC(V) program predominantly attracts underprivileged students and is rarely their first choice. This research highlights that the NC(V) program does not fully empower or transform students’ circumstances, instead perpetuating cycles of poverty, unemployment, and social inequality—contrary to Freire’s vision of education as a tool for liberation and societal change. The program fails to provide meaningful employment opportunities, leaving graduates often unemployed or in low-paying jobs, unable to escape poverty. This underscores the program’s inadequacies. Furthermore, insufficient support structures and practical application opportunities further diminish graduates’ employability. The study’s findings emphasise the need for systemic reforms in the NC(V) program. Embracing Freire’s principles and moving beyond traditional banking education models to more inclusive, participatory approaches is essential. This transformation is crucial for the TVET system to genuinely empower students and foster significant personal and societal change. , Thesis (PhD) -- Faculty of Education, School of Secondary School Education, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Majola, Ezekiel
- Date: 2024-12
- Subjects: Vocational education -- Eastern Cape -- South Africa , Technical education -- Eastern Cape -- South Africa , School-to-work transition -- Eastern Cape -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/${Handle} , vital:76985
- Description: This study employs Paulo Freire’s framework to contribute to debates surrounding social justice and transformation in vocational education and training (TVET). By offering a critical perspective on dominant discourse and practices, it challenges prevailing trajectories of powerful knowledge and inherent assumptions and biases in TVET. Drawing on a Freirean framework, the research provides insights to develop more equitable and transformative practices by addressing power, privilege, and social inequality in TVET. Through dialogue and collaboration with students, it promotes critical consciousness and relevant skills and knowledge. Highlighting the significance of context, it underscores the need to understand the social and cultural context of learning. Demonstrating the potential of a Freirean framework to challenge the status quo, it promotes more equitable and empowering practices in TVET. The chosen methodology for this study is Participatory Action Research (PAR), integrating theory, action, and participation to address social issues. Recruiting 15 NC(V) graduates from Algoa TVET College, forming a Learning Cycle Group (LCG), the study aimed to comprehend graduates’ experiences, challenges, and opportunities. Life narrative interviews and LCG meetings generated data, ensuring every participant had a voice and strengthening group cohesion. Data were grounded in ethical values such as respect, equality, inclusion, democratic participation, active learning, making a difference, collective action, and personal integrity. Employing Paulo Freire’s theoretical framework, this study offers a novel perspective on TVET in South Africa, fostering dialogue with TVET students to challenge conventional discourses. It aimed to develop an alternative conceptualisation of TVET by incorporating student experiences and perspectives, promoting positive change through dialogue and addressing power dynamics and social justice issues. The study explores Powell’s (2014) question regarding TVET colleges’ role in expanding opportunities for students and asks: “How do TVET graduates experience life after graduation? Are they empowered and satisfied with their social status?” Sub-questions inquire about students’ expectations upon enrolling, opportunities after completing NC(V) programs, and the extent to which TVET colleges address unemployment and socio-economic injustices, aiming to inspire the development of praxis and frameworks that better serve the needs of TVET graduates and address social concerns.The study’s findings, analysed through Freire’s ideology in “We Make the Road by Walking” (1990) and “Pedagogy of Hope” (1994), reveal that the NC(V) program predominantly attracts underprivileged students and is rarely their first choice. This research highlights that the NC(V) program does not fully empower or transform students’ circumstances, instead perpetuating cycles of poverty, unemployment, and social inequality—contrary to Freire’s vision of education as a tool for liberation and societal change. The program fails to provide meaningful employment opportunities, leaving graduates often unemployed or in low-paying jobs, unable to escape poverty. This underscores the program’s inadequacies. Furthermore, insufficient support structures and practical application opportunities further diminish graduates’ employability. The study’s findings emphasise the need for systemic reforms in the NC(V) program. Embracing Freire’s principles and moving beyond traditional banking education models to more inclusive, participatory approaches is essential. This transformation is crucial for the TVET system to genuinely empower students and foster significant personal and societal change. , Thesis (PhD) -- Faculty of Education, School of Secondary School Education, 2024
- Full Text:
- Date Issued: 2024-12
(In)security communities in Africa: small arms and light weapons norm compliance by the economic community of West African states
- Authors: Pokoo, John Mark
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/467093 , vital:76814
- Description: Access restricted. Expected release in 2026. , Thesis (PhD) -- Faculty of Humanities, Political and International Studies, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Pokoo, John Mark
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/467093 , vital:76814
- Description: Access restricted. Expected release in 2026. , Thesis (PhD) -- Faculty of Humanities, Political and International Studies, 2024
- Full Text:
- Date Issued: 2024-10-11
A case study of GADRA’s community-engaged praxis for educational transformation
- Authors: Msomi, Nqobile Nomonde
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/464864 , vital:76552 , DOI https://doi.org/10.21504/10962/464864
- Description: Although South Africa has achieved considerable steps in development over the last thirty years, post-apartheid South Africa is characterised by widespread poverty, high unemployment and systemic inequality. According to the country’s National Planning Commission, education is central to achieving the overarching democratic goals of eliminating poverty and reducing inequality. This positions education as an important site for the liberation and well-being of our country’s majority. This case study takes a community psychology perspective on education; more specifically the education-development nexus wherein Non-Governmental Organisations (NGOs) are centrally positioned. NGOs are contentiously positioned in the development discourse. Nonetheless, they have played a key role with regards to siding with the poor, the excluded, persistently marginalised and oppressed majority and to bringing about social justice, following South Africa’s colonial and apartheid histories, as well as in the current democratic dispensation. This study situates a local NGO, GADRA Education, within the country’s socio-political and educational landscape. Founded in the 1950s and located in Makhanda, it has been operating in the rural Eastern Cape province for more than sixty years. In the present-day, GADRA Education positions itself at the centre of a dense network of education institutions in Makhanda, including Rhodes University, and collaborates with a number of education stakeholders in the small city. The case study consisted of two consecutive phases: a Foucauldian discourse analysis of GADRA’s annual reports between 2012 and 2021, followed by individual narrative interviews with 13 organisational members. An Africa(n)-centred community psychology orientation, revealed counter-discourse to the national “crisis in education” discourse surrounding the NGO. The discourse of crisis produced the legitimation for GADRA Education’s continued existence, action and embeddedness in Makhanda. The discourse of transformation informed their modes of support across primary, secondary and higher education. The discourse of access and participation constructed the NGO as a bridge and link between phases of education. The discourse of collaborative partnerships enabled solidarity between state and non-state actors towards educational change. Finally, the discourse of development positioned development at a grassroots level. These constellations formed GADRA Education’s counter-discourse, which produced the Organisation’s apparatus of resistance, formulated as situated praxis. The 5 organisational members’ narratives revealed the apparatus’s impacts on the subjectivities of youth in Makhanda in engendering hope and driving educational change in the city. In contrast to conceptions of education NGOs who work in the public schooling sector making little progress in dismantling educational inequity, this study illustrates the techniques of resistance leveraged, in the context of collaborative partnerships, by the local NGO. These techniques have wider applicability for education-development practitioners concerned with transformative change in their educational locales. It illustrates the principles and modes by which NGOs can operate in solidarity with the persistently marginalised majority, and thus contribute to shaping our imagined educational futures. I argue that psychology is a useful site to think about justice. Critical psychological theory can enable a deeper understanding of practice that contributes to impactful community organisation, intervention and resistance in the country’s education sector. The operationalisation of the values and principles of community psychology can make important contributions at the nexus of theory and practice in working towards educational, and ultimately social, change. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Msomi, Nqobile Nomonde
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/464864 , vital:76552 , DOI https://doi.org/10.21504/10962/464864
- Description: Although South Africa has achieved considerable steps in development over the last thirty years, post-apartheid South Africa is characterised by widespread poverty, high unemployment and systemic inequality. According to the country’s National Planning Commission, education is central to achieving the overarching democratic goals of eliminating poverty and reducing inequality. This positions education as an important site for the liberation and well-being of our country’s majority. This case study takes a community psychology perspective on education; more specifically the education-development nexus wherein Non-Governmental Organisations (NGOs) are centrally positioned. NGOs are contentiously positioned in the development discourse. Nonetheless, they have played a key role with regards to siding with the poor, the excluded, persistently marginalised and oppressed majority and to bringing about social justice, following South Africa’s colonial and apartheid histories, as well as in the current democratic dispensation. This study situates a local NGO, GADRA Education, within the country’s socio-political and educational landscape. Founded in the 1950s and located in Makhanda, it has been operating in the rural Eastern Cape province for more than sixty years. In the present-day, GADRA Education positions itself at the centre of a dense network of education institutions in Makhanda, including Rhodes University, and collaborates with a number of education stakeholders in the small city. The case study consisted of two consecutive phases: a Foucauldian discourse analysis of GADRA’s annual reports between 2012 and 2021, followed by individual narrative interviews with 13 organisational members. An Africa(n)-centred community psychology orientation, revealed counter-discourse to the national “crisis in education” discourse surrounding the NGO. The discourse of crisis produced the legitimation for GADRA Education’s continued existence, action and embeddedness in Makhanda. The discourse of transformation informed their modes of support across primary, secondary and higher education. The discourse of access and participation constructed the NGO as a bridge and link between phases of education. The discourse of collaborative partnerships enabled solidarity between state and non-state actors towards educational change. Finally, the discourse of development positioned development at a grassroots level. These constellations formed GADRA Education’s counter-discourse, which produced the Organisation’s apparatus of resistance, formulated as situated praxis. The 5 organisational members’ narratives revealed the apparatus’s impacts on the subjectivities of youth in Makhanda in engendering hope and driving educational change in the city. In contrast to conceptions of education NGOs who work in the public schooling sector making little progress in dismantling educational inequity, this study illustrates the techniques of resistance leveraged, in the context of collaborative partnerships, by the local NGO. These techniques have wider applicability for education-development practitioners concerned with transformative change in their educational locales. It illustrates the principles and modes by which NGOs can operate in solidarity with the persistently marginalised majority, and thus contribute to shaping our imagined educational futures. I argue that psychology is a useful site to think about justice. Critical psychological theory can enable a deeper understanding of practice that contributes to impactful community organisation, intervention and resistance in the country’s education sector. The operationalisation of the values and principles of community psychology can make important contributions at the nexus of theory and practice in working towards educational, and ultimately social, change. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2024
- Full Text:
- Date Issued: 2024-10-11
A conspiracy of silence: the authorial potential of full masks in performer training, dramaturgy and audience perception in South African visual theatre
- Authors: Murray, Robert Ian
- Date: 2024-10-11
- Subjects: Liezl de Kock , People with disabilities and the performing arts , Experimental theater South Africa , Actors Training of , Theater for deaf people South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/467083 , vital:76813 , DOI https://doi.org/10.21504/10962/467083
- Description: Silent Mask Theatre in South Africa has the potential to cut across linguistic divides and deliver a product that offers an intimate, unique experience for the audience as well as the actor. South Africa not only has a complicated history, but also 11 languages (12 if one counts South African Sign Language – SASL -, which still holds a curious position of being counted official or not), and the one that theatre-makers choose to present in gives a certain “authority” to the production. Silent masks remove the need for linguistic understanding, something necessary for more abstract thought, and focusses instead on the emotional relevance and interplay between characters. In doing so, it proves an important way to create relevance for an audience, creating a delicate dance between the Mask (character and thereby text), how the actor plays it, and then the closing of meaning through the audience experience. Thus, is created a trialogue between these elements that gives the production the opportunity to speak to the hearts and minds of the audience. Globally, the study of silent character masks is still relatively new, with proponents of it only coming to the fore in the past few years (Wilsher, 2007). Mask Theatre has grown exponentially in the UK and Europe with companies like Vamos Theatre, exploring PTSD in works like A Brave Face (2018) or death in Dead Good (2021), and Familie Flöz either on the more whimsical side like Hotel Paradiso (2011) or the more hard-hitting Infinito (2006), gaining popularity and exposure. In South Africa, there is strangely not an indigenous tradition of masks, as opposed to other parts of Africa. This is fascinating, and probably points towards a more “oral tradition” of South Africa/Africa. However, the author aims to point out the ways that the silent mask entered South African consciousness at a time where more attention was being paid to “performing objects” (Proschan, 1985), and particularly in Cape Town with the advent of the Out the Box Festival. This thesis aims to contextualise Visual Theatre and Mask Theatre in a South African context, seeing within it a movement towards a more global perspective of puppetry, material performances, and performing objects. Although “ghettoised” for a long time (Taylor, 2004), performing objects emerged and became a leading case for the primal “text” of a performance. Handspring Puppet Company, Janni Younge, and the author’s company, FTH:K, became primary grounds of contestation against more conventional, text-based theatre. Starting with a reflective account of the author’s journey towards masks, the thesis branches out into a reflection on its author’s pedagogical praxis, and how silent masks work, before critically reflecting on and analysing his key works, such as Pictures of You (2008-2013), which deals with home invasions and grief, and Benchmarks (2011), which deals with the wave of xenophobia that hit South Africa around that time. . This were built from the ground up, working with current issues both in the author’s, and the country’s, mileau. In the last two decades, performing object work in South Africa has begun to flourish. This is the first thesis to investigate mask work in the country during this period. Its possibilities for Screen and Stage Acting are still being explored. , Thesis (PhD) -- Faculty of Humanities, Drama, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Murray, Robert Ian
- Date: 2024-10-11
- Subjects: Liezl de Kock , People with disabilities and the performing arts , Experimental theater South Africa , Actors Training of , Theater for deaf people South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/467083 , vital:76813 , DOI https://doi.org/10.21504/10962/467083
- Description: Silent Mask Theatre in South Africa has the potential to cut across linguistic divides and deliver a product that offers an intimate, unique experience for the audience as well as the actor. South Africa not only has a complicated history, but also 11 languages (12 if one counts South African Sign Language – SASL -, which still holds a curious position of being counted official or not), and the one that theatre-makers choose to present in gives a certain “authority” to the production. Silent masks remove the need for linguistic understanding, something necessary for more abstract thought, and focusses instead on the emotional relevance and interplay between characters. In doing so, it proves an important way to create relevance for an audience, creating a delicate dance between the Mask (character and thereby text), how the actor plays it, and then the closing of meaning through the audience experience. Thus, is created a trialogue between these elements that gives the production the opportunity to speak to the hearts and minds of the audience. Globally, the study of silent character masks is still relatively new, with proponents of it only coming to the fore in the past few years (Wilsher, 2007). Mask Theatre has grown exponentially in the UK and Europe with companies like Vamos Theatre, exploring PTSD in works like A Brave Face (2018) or death in Dead Good (2021), and Familie Flöz either on the more whimsical side like Hotel Paradiso (2011) or the more hard-hitting Infinito (2006), gaining popularity and exposure. In South Africa, there is strangely not an indigenous tradition of masks, as opposed to other parts of Africa. This is fascinating, and probably points towards a more “oral tradition” of South Africa/Africa. However, the author aims to point out the ways that the silent mask entered South African consciousness at a time where more attention was being paid to “performing objects” (Proschan, 1985), and particularly in Cape Town with the advent of the Out the Box Festival. This thesis aims to contextualise Visual Theatre and Mask Theatre in a South African context, seeing within it a movement towards a more global perspective of puppetry, material performances, and performing objects. Although “ghettoised” for a long time (Taylor, 2004), performing objects emerged and became a leading case for the primal “text” of a performance. Handspring Puppet Company, Janni Younge, and the author’s company, FTH:K, became primary grounds of contestation against more conventional, text-based theatre. Starting with a reflective account of the author’s journey towards masks, the thesis branches out into a reflection on its author’s pedagogical praxis, and how silent masks work, before critically reflecting on and analysing his key works, such as Pictures of You (2008-2013), which deals with home invasions and grief, and Benchmarks (2011), which deals with the wave of xenophobia that hit South Africa around that time. . This were built from the ground up, working with current issues both in the author’s, and the country’s, mileau. In the last two decades, performing object work in South Africa has begun to flourish. This is the first thesis to investigate mask work in the country during this period. Its possibilities for Screen and Stage Acting are still being explored. , Thesis (PhD) -- Faculty of Humanities, Drama, 2024
- Full Text:
- Date Issued: 2024-10-11
A house accursed: reconsidering Sophocles’ sisters, Antigone & Ismene
- Authors: Fox, Peta Ann , Sophocles
- Date: 2024-10-11
- Subjects: Ismene (Greek mythology) , Antigone (Greek mythological figure) , Electra (Greek mythological figure) , Chrysothemis , Greek tragedy , Sisters in literature
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/467028 , vital:76808 , DOI https://doi.org/10.21504/10962/467028
- Description: Traditionally, Ismene’s refusal to help Antigone bury their brother in Sophocles’ Antigone tends to be regarded only in relation to Antigone’s own remarkable bravery. Antigone exists on the heroic level, Ismene on the ordinary; Antigone is courageous, Ismene is timid and submissive; Antigone is an idealist and an individualist, Ismene is convention and herd-bound. Ismene is, in many ways, presented as the antithesis of Antigone and Sophocles does indeed make use of her character as a foil to Antigone, but this thesis will argue that the relation between the two sisters is far more complicated than a dichotomous contrast between ‘extraordinary heroine’ and ‘average woman’. Like Antigone, Ismene is very much a character in her own right, and her emotions, motivations and impulses are every bit as realised and compelling as Antigone’s own. Both sisters have been deeply affected by the tragic misfortunes of their family, but their sad history affects each sister quite differently. Whereas Antigone’s instinctive reaction to Creon’s edict is a furious determination not to tolerate any further dishonour, Ismene’s equally instinctive reaction is to avoid the pattern of self-destructive inwardness that has plagued their family for generations. By offering a comprehensive re-examination of the key passages that have informed our critical reception of Ismene and the nature of her relationship with Antigone, this study aims to disrupt the established, and largely prejudiced, reading of Ismene as a model of feminine timidity and submission. Although Ismene is certainly no grand tragic heroine, titling the theoretical focus away from the death-oriented extremism of Antigone towards a more balanced consideration of the so-called ‘weaker sister’ not only allows for new insights into the nature of Sophoclean tragedy, but also challenges the very basis on which Ismene has so often been dismissed in favour of her more intrepid sister: the pervasive assumption that Sophocles has only given us one sister who is willing to risk her life for a principle. , Thesis (PhD) -- Faculty of Humanities, School of Languages and Literatures, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Fox, Peta Ann , Sophocles
- Date: 2024-10-11
- Subjects: Ismene (Greek mythology) , Antigone (Greek mythological figure) , Electra (Greek mythological figure) , Chrysothemis , Greek tragedy , Sisters in literature
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/467028 , vital:76808 , DOI https://doi.org/10.21504/10962/467028
- Description: Traditionally, Ismene’s refusal to help Antigone bury their brother in Sophocles’ Antigone tends to be regarded only in relation to Antigone’s own remarkable bravery. Antigone exists on the heroic level, Ismene on the ordinary; Antigone is courageous, Ismene is timid and submissive; Antigone is an idealist and an individualist, Ismene is convention and herd-bound. Ismene is, in many ways, presented as the antithesis of Antigone and Sophocles does indeed make use of her character as a foil to Antigone, but this thesis will argue that the relation between the two sisters is far more complicated than a dichotomous contrast between ‘extraordinary heroine’ and ‘average woman’. Like Antigone, Ismene is very much a character in her own right, and her emotions, motivations and impulses are every bit as realised and compelling as Antigone’s own. Both sisters have been deeply affected by the tragic misfortunes of their family, but their sad history affects each sister quite differently. Whereas Antigone’s instinctive reaction to Creon’s edict is a furious determination not to tolerate any further dishonour, Ismene’s equally instinctive reaction is to avoid the pattern of self-destructive inwardness that has plagued their family for generations. By offering a comprehensive re-examination of the key passages that have informed our critical reception of Ismene and the nature of her relationship with Antigone, this study aims to disrupt the established, and largely prejudiced, reading of Ismene as a model of feminine timidity and submission. Although Ismene is certainly no grand tragic heroine, titling the theoretical focus away from the death-oriented extremism of Antigone towards a more balanced consideration of the so-called ‘weaker sister’ not only allows for new insights into the nature of Sophoclean tragedy, but also challenges the very basis on which Ismene has so often been dismissed in favour of her more intrepid sister: the pervasive assumption that Sophocles has only given us one sister who is willing to risk her life for a principle. , Thesis (PhD) -- Faculty of Humanities, School of Languages and Literatures, 2024
- Full Text:
- Date Issued: 2024-10-11