Silica supported sulfuric acid-catalysed one-pot processes for the synthesis of n-heterocycles
- Authors: Ndagano, Urbain Nshokano
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431921 , vital:72815
- Description: Access restricted. Expected release in 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Authors: Ndagano, Urbain Nshokano
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431921 , vital:72815
- Description: Access restricted. Expected release in 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
Singing madness: three performative analyses of the “mad scene” from Lucia di Lammermoor
- Authors: Le Kay, Jo-Nette
- Date: 2023-10-13
- Subjects: Mental illness in music , Bel canto , Donizetti, Gaetano, 1797-1848. Lucia di Lammermoor. Dolce suono , Coloratura soprano , Embellishment (Vocal music) , Performativity
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425377 , vital:72234
- Description: This study describes three internationally recognised sopranos and their presentations of character psychology on stage, during their performances of the famous “mad scene” from Gaetano Donizetti’s opera Lucia di Lammermoor. These sopranos are Joan Sutherland, Mariella Devia, and Lisette Oropesa. I use Margaret Kartomi’s (2014) model of performativity to interpret the “madness” depicted by the three selected sopranos, as based on my interpretations of commercially released audio-visual recordings of their performances in the role of Lucia. Through analysing these performances with the help of Kartomi’s performativity model (which focuses on persona, emotion-and intersubjectivity, and reception), my research determines – with speculative interpretation, and within the reasonable limits of standard psychiatric frameworks – which mental illnesses the sopranos can be understood to have portrayed in their interpretations of the role of Lucia. The study’s goal is not to make an accurate mental health diagnosis of someone’s portrayal of a fictional character. (Considering the fact that one cannot make accurate mental health diagnoses for people who do not exist.) Rather, my focus is to discover which dramatic and possibly musical characteristics are utilised to perform this fictional character and give expressive content to her “madness”. The concept of “madness” and its psychological characterisation during performance thus becomes the framework from which to interpret and understand vocal and acting techniques related to opera in general and to bel canto more specifically. My research findings are that the three performers use facial expressions, different aspects of using the voice through bel canto singing, and body movements as a way of expression. Bel canto characteristics include coloratura embellishments, fioritura, melismas, messa di voce, squillo and chiaroscuro. The sopranos also show musical and dramatic elements in how they respond to the flute or glass harmonica during the ‘Mad Scene’ – which counts as the personae expressed by the performers. These personae are further applied in the emotional and intersubjectivity and the reception aspects of Kartomi’s performativity model. In the emotional and intersubjectivity aspect, the chorus and other characters singing on stage are read as emphasising the reaction of society on the mentally dysfunctional behaviour enacted by the sopranos. In the reception aspect, reviewers are used to filling in for audience members. I read their reactions as contributing factors in forming an understanding of the interpretations of the “mad scene” performed by the three sopranos. My reading of the three interpretations of the “mad scene” goes further by subjectively interpreting how these sopranos approximate different states of mental collapse. These readings include approximations of psychosis such as mania, dissociative personality disorder, and paranoid schizophrenic behaviour. Always, though, these mental health behaviours are identified as approximations to better understand vocal and acting techniques. , Thesis (MMus) -- Faculty of Humanities, Music and Musicology, 2023
- Full Text:
- Authors: Le Kay, Jo-Nette
- Date: 2023-10-13
- Subjects: Mental illness in music , Bel canto , Donizetti, Gaetano, 1797-1848. Lucia di Lammermoor. Dolce suono , Coloratura soprano , Embellishment (Vocal music) , Performativity
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425377 , vital:72234
- Description: This study describes three internationally recognised sopranos and their presentations of character psychology on stage, during their performances of the famous “mad scene” from Gaetano Donizetti’s opera Lucia di Lammermoor. These sopranos are Joan Sutherland, Mariella Devia, and Lisette Oropesa. I use Margaret Kartomi’s (2014) model of performativity to interpret the “madness” depicted by the three selected sopranos, as based on my interpretations of commercially released audio-visual recordings of their performances in the role of Lucia. Through analysing these performances with the help of Kartomi’s performativity model (which focuses on persona, emotion-and intersubjectivity, and reception), my research determines – with speculative interpretation, and within the reasonable limits of standard psychiatric frameworks – which mental illnesses the sopranos can be understood to have portrayed in their interpretations of the role of Lucia. The study’s goal is not to make an accurate mental health diagnosis of someone’s portrayal of a fictional character. (Considering the fact that one cannot make accurate mental health diagnoses for people who do not exist.) Rather, my focus is to discover which dramatic and possibly musical characteristics are utilised to perform this fictional character and give expressive content to her “madness”. The concept of “madness” and its psychological characterisation during performance thus becomes the framework from which to interpret and understand vocal and acting techniques related to opera in general and to bel canto more specifically. My research findings are that the three performers use facial expressions, different aspects of using the voice through bel canto singing, and body movements as a way of expression. Bel canto characteristics include coloratura embellishments, fioritura, melismas, messa di voce, squillo and chiaroscuro. The sopranos also show musical and dramatic elements in how they respond to the flute or glass harmonica during the ‘Mad Scene’ – which counts as the personae expressed by the performers. These personae are further applied in the emotional and intersubjectivity and the reception aspects of Kartomi’s performativity model. In the emotional and intersubjectivity aspect, the chorus and other characters singing on stage are read as emphasising the reaction of society on the mentally dysfunctional behaviour enacted by the sopranos. In the reception aspect, reviewers are used to filling in for audience members. I read their reactions as contributing factors in forming an understanding of the interpretations of the “mad scene” performed by the three sopranos. My reading of the three interpretations of the “mad scene” goes further by subjectively interpreting how these sopranos approximate different states of mental collapse. These readings include approximations of psychosis such as mania, dissociative personality disorder, and paranoid schizophrenic behaviour. Always, though, these mental health behaviours are identified as approximations to better understand vocal and acting techniques. , Thesis (MMus) -- Faculty of Humanities, Music and Musicology, 2023
- Full Text:
Social entrepreneurship and the tensions between social, environmental, and business goals: a case of Uganda
- Authors: Okello, Emmanuel
- Date: 2023-10-13
- Subjects: Social entrepreneurship Uganda , Climatic changes Uganda , Social responsibility of business Uganda , Sustainable development Uganda , Environmental responsibility Uganda
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419662 , vital:71664
- Description: Climate change has resulted in a global environmental crisis, with deforestation, plastic pollution, soil degradation, and species extinction increasing. Businesses have contributed significantly to these issues through their manufacturing processes. While many companies have implemented sustainability initiatives, systemic environmental problems persist, and businesses continue to play a significant role. One reason for this is that profit often takes priority over environmental considerations, limiting the effectiveness of sustainability programs. In response, environmental social enterprises are gaining prominence as a potent alternative to conventional business models. These enterprises are commended for placing environmental value generation at their core. Nevertheless, the simultaneous pursuit of financial, socio-economic, and environmental goals can instigate conflicts, including those related to performing, organizing, belonging, learning, and those spanning various levels of analysis. These conflicts impede the intended outcomes of these enterprises. This challenge is particularly under-addressed within contexts distinct from North America and Europe, like Uganda, which possesses unique geographic, political, and cultural attributes. Investigating how environmental social enterprises in Uganda navigate goal-related contradictions is pivotal for comprehending their internal mechanisms and strategies for economic sustainability. This study adopted a qualitative research strategy grounded in the interpretivist paradigm. Employing multi-qualitative methods, including interviews with 20 key decision-makers from 4 environmental social enterprises, the study delved into their experiences and practices. The findings revealed that these enterprises grapple with tensions stemming from their endeavors to balance economic, environmental, and social objectives. These tensions manifest both anticipated and unanticipated effects on organizational performance. Strategies for managing these tensions encompass collaborations with other organizations, experimentation with diverse management approaches, and acknowledging tensions as inherent and potentially beneficial. Nevertheless, the efficacy of these strategies hinges on the organizational context and systemic factors such as government regulations. While facing similar tensions, environmental social enterprises also adopt varied tactics—proactive, defensive, or a combination thereof—to address conflicts rooted in their goals. The chosen response method holds implications for ecological outcomes, underscoring the importance of framing tensions appropriately. Nonetheless, persistent tensions that resurface due to their dynamic nature pose a challenge. Consequently, addressing such tensions necessitates an iterative approach, often entailing a fusion of strategies. To address tensions between social, environmental, and economic objectives in environmental social enterprises, policymakers, governments, and social entrepreneurs should collaborate to institute supportive policies, encourage partnerships, invest in education and capacity building, and establish evaluation frameworks. Implementing these recommendations can adeptly manage such conflicts, fostering sustainable development and success. , Thesis (MCom) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
- Authors: Okello, Emmanuel
- Date: 2023-10-13
- Subjects: Social entrepreneurship Uganda , Climatic changes Uganda , Social responsibility of business Uganda , Sustainable development Uganda , Environmental responsibility Uganda
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419662 , vital:71664
- Description: Climate change has resulted in a global environmental crisis, with deforestation, plastic pollution, soil degradation, and species extinction increasing. Businesses have contributed significantly to these issues through their manufacturing processes. While many companies have implemented sustainability initiatives, systemic environmental problems persist, and businesses continue to play a significant role. One reason for this is that profit often takes priority over environmental considerations, limiting the effectiveness of sustainability programs. In response, environmental social enterprises are gaining prominence as a potent alternative to conventional business models. These enterprises are commended for placing environmental value generation at their core. Nevertheless, the simultaneous pursuit of financial, socio-economic, and environmental goals can instigate conflicts, including those related to performing, organizing, belonging, learning, and those spanning various levels of analysis. These conflicts impede the intended outcomes of these enterprises. This challenge is particularly under-addressed within contexts distinct from North America and Europe, like Uganda, which possesses unique geographic, political, and cultural attributes. Investigating how environmental social enterprises in Uganda navigate goal-related contradictions is pivotal for comprehending their internal mechanisms and strategies for economic sustainability. This study adopted a qualitative research strategy grounded in the interpretivist paradigm. Employing multi-qualitative methods, including interviews with 20 key decision-makers from 4 environmental social enterprises, the study delved into their experiences and practices. The findings revealed that these enterprises grapple with tensions stemming from their endeavors to balance economic, environmental, and social objectives. These tensions manifest both anticipated and unanticipated effects on organizational performance. Strategies for managing these tensions encompass collaborations with other organizations, experimentation with diverse management approaches, and acknowledging tensions as inherent and potentially beneficial. Nevertheless, the efficacy of these strategies hinges on the organizational context and systemic factors such as government regulations. While facing similar tensions, environmental social enterprises also adopt varied tactics—proactive, defensive, or a combination thereof—to address conflicts rooted in their goals. The chosen response method holds implications for ecological outcomes, underscoring the importance of framing tensions appropriately. Nonetheless, persistent tensions that resurface due to their dynamic nature pose a challenge. Consequently, addressing such tensions necessitates an iterative approach, often entailing a fusion of strategies. To address tensions between social, environmental, and economic objectives in environmental social enterprises, policymakers, governments, and social entrepreneurs should collaborate to institute supportive policies, encourage partnerships, invest in education and capacity building, and establish evaluation frameworks. Implementing these recommendations can adeptly manage such conflicts, fostering sustainable development and success. , Thesis (MCom) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
Social Learning and Regenerative Sustainability: Unlocking value created in sustainability projects in higher education
- Authors: Royle, Carlene
- Date: 2023-10-13
- Subjects: Social Learning South Africa Makhanda , Sustainability South Africa Makhanda , Education, Higher Social aspects South Africa Makhanda , Social accounting South Africa Makhanda , Education, Higher Activity programs South Africa Makhanda , Value creation , Agent (Philosophy) , Sustainable Development Goals
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/402981 , vital:69911
- Description: This qualitative study considers two bodies of theory, regenerative sustainability and social learning theory, within a tertiary education context. Universities offer unique opportunities, across both the formal and informal curriculum, that engage with the two-fold socioeconomic and environmental crises. The study explores both the promise of unlocking value in an ex-linear economy; and the healing and regenerative benefits in moving toward greener practices. Through an embedded case study at Rhodes University, in the Eastern Cape of South Africa, this research explores the value that is being unlocked in campus-based sustainability projects, when considered through a social learning lens (Lave and Wenger, 1991). Invitations to participate in this study were extended to project-leads of sustainability initiatives originating from Rhodes University campus. Six projects, which have been active on campus in recent years, were selected and, through semi-structured interviews, the insights of 12 participants were captured and analysed using the associated Value Creation Framework (VCF) developed by Wenger, Trayner and De Laat (Wenger, Trayner, de Laat, 2011) and later Wenger-Trayner and Wenger Trayner (2014, 2015, 2020). The VCF consists of value cycles that interconnect dynamically, including Orientating, Strategic, Enabling, Immediate, Potential, Applied, Realised and Reframed or Transformative value cycles. The study identified instances of all these value cycles, within and across the six embedded case studies (project). Drawing on social learning theorists the analysis further focused on instances of collaboration, agency and boundary crossing. Additional themes that emerged across the majority of the embedded study projects, were a convergence of socio and eco; a whole-systems perspective shared by project leads; the importance of the social commons; language as an enabler; and problem solving for system change. A recommendation is proposed to further unlock the unbounded value created through such projects by reframing the informal curriculum opportunities offered on university campuses as social learning spaces where students can practice agency. To do so, would require formalizing various forms of system support, thus facilitating expanded learning in regenerative sustainability activities, for the common social and planetary good. , Thesis (MEd) -- Faculty of Education, Education, 2023
- Full Text:
- Authors: Royle, Carlene
- Date: 2023-10-13
- Subjects: Social Learning South Africa Makhanda , Sustainability South Africa Makhanda , Education, Higher Social aspects South Africa Makhanda , Social accounting South Africa Makhanda , Education, Higher Activity programs South Africa Makhanda , Value creation , Agent (Philosophy) , Sustainable Development Goals
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/402981 , vital:69911
- Description: This qualitative study considers two bodies of theory, regenerative sustainability and social learning theory, within a tertiary education context. Universities offer unique opportunities, across both the formal and informal curriculum, that engage with the two-fold socioeconomic and environmental crises. The study explores both the promise of unlocking value in an ex-linear economy; and the healing and regenerative benefits in moving toward greener practices. Through an embedded case study at Rhodes University, in the Eastern Cape of South Africa, this research explores the value that is being unlocked in campus-based sustainability projects, when considered through a social learning lens (Lave and Wenger, 1991). Invitations to participate in this study were extended to project-leads of sustainability initiatives originating from Rhodes University campus. Six projects, which have been active on campus in recent years, were selected and, through semi-structured interviews, the insights of 12 participants were captured and analysed using the associated Value Creation Framework (VCF) developed by Wenger, Trayner and De Laat (Wenger, Trayner, de Laat, 2011) and later Wenger-Trayner and Wenger Trayner (2014, 2015, 2020). The VCF consists of value cycles that interconnect dynamically, including Orientating, Strategic, Enabling, Immediate, Potential, Applied, Realised and Reframed or Transformative value cycles. The study identified instances of all these value cycles, within and across the six embedded case studies (project). Drawing on social learning theorists the analysis further focused on instances of collaboration, agency and boundary crossing. Additional themes that emerged across the majority of the embedded study projects, were a convergence of socio and eco; a whole-systems perspective shared by project leads; the importance of the social commons; language as an enabler; and problem solving for system change. A recommendation is proposed to further unlock the unbounded value created through such projects by reframing the informal curriculum opportunities offered on university campuses as social learning spaces where students can practice agency. To do so, would require formalizing various forms of system support, thus facilitating expanded learning in regenerative sustainability activities, for the common social and planetary good. , Thesis (MEd) -- Faculty of Education, Education, 2023
- Full Text:
South African women’s experience of the decision, procedure and recovery from “feticide” and late termination of pregnancy due to the presence of severe fetal abnormality: women’s and health service providers’ perspectives
- Authors: Vorster, Angela Carol
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432359 , vital:72864 , DOI 10.21504/10962/432359
- Description: Routine antenatal care, including sonography and genetic testing, assist healthcare providers in identifying the presence of severe fetal abnormality. In countries where it is legal, the option to abort such a pregnancy may be presented to the pregnant person. When abortion takes place after the thirteenth week of gestation, it is generally referred to as a late termination of pregnancy and may entail the induction of labour or caesarean section. In cases where termination of the pregnancy is decided upon, and the gestation is further than 21 weeks and six days, the feticide procedure is recommended in order to ensure stillbirth. The feticide procedure entails the injection of potassium chloride directly into the fetal heart in order to ensure fetal demise. Existing literature on “feticide” and late termination of pregnancy (LTOP) owing to fetal abnormalities mostly takes a medical or psychological perspective in researching these procedures. Within the South African context, there are very few studies on feticide and LTOP, with none of these studies (to date – 8 January 2023) taking a feminist approach. This paucity of research that takes into account power relations, structural inequality and factors that affect decision-making and choice is one of the reasons that this study was undertaken. The main research question focused on in this study is: What are South African women’s experiences of feticide and late termination of pregnancy due to the presence of severe fetal abnormality, as related by the women themselves and the health service providers who perform the procedure or provide care? The sub-questions that initially drove the study were: How do the women relate their experience of the process of coming to the decision, undergoing and recovering from the procedure, and how do health service providers relate the experiences of these women? The methodological and theoretical framework employed in this research was a Feminist Social Constructionist approach to Grounded Theory. This reflexive, subjectivist, feminist lens encouraged awareness of the influence of gender, race, class and other structural and systemic factors on women’s experiences within the two healthcare systems. Data collection entailed semi-structured interviews conducted with 12 women, who had undergone feticide and LTOP procedures between one and five years prior to the interviews, in either the public or private healthcare system in South Africa. Semi-structured interviews were also conducted with 13 healthcare providers. The providers included medical specialists and participants from the fields of clinical psychology, genetic counselling and nursing and were employed in public or private healthcare in South Africa. Data relevant to public healthcare users and providers were collected from one tertiary (academic) public healthcare hospital and data regarding private healthcare users and providers were collected from across South Africa. Women’s constructions of their experiences of feticide and LTOP included stark contrasts between public and private healthcare users in South Africa, as well as women experiencing “no choice” and their voices being ignored or silenced. Healthcare providers’ constructions were frequently contradictory, referring to women as having freedom of choice and their needs largely prioritised within the healthcare system, while the providers within the public healthcare system relayed their own frustrations and emotional burden due to systemic failures. Findings from women and providers’ constructions were synthesised into a theoretical understanding of women’s experiences of feticide and LTOP in South Africa, which is grounded in, and emergent from, the data. Women’s experiences of feticide and LTOP in South Africa were conceptualised by framing the three phases of these experiences, namely the decision-making phase (I), undergoing the procedures and in-hospital recovery (phase II) and the recovery phase (III). The most prominent themes emerging in these phases included the schism between the public and private healthcare systems in South Africa, the lack of real choice women experience, as well as the silencing of women and providers with regard to feticide and LTOP. Underlying the three phases, and directly influencing the three prominent themes affecting women’s experiences, were the underlying and insidious structural inequality that undermined reproductive justice with regard to women’s decision-making, experiences of and recovery from feticide and LTOP. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Authors: Vorster, Angela Carol
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432359 , vital:72864 , DOI 10.21504/10962/432359
- Description: Routine antenatal care, including sonography and genetic testing, assist healthcare providers in identifying the presence of severe fetal abnormality. In countries where it is legal, the option to abort such a pregnancy may be presented to the pregnant person. When abortion takes place after the thirteenth week of gestation, it is generally referred to as a late termination of pregnancy and may entail the induction of labour or caesarean section. In cases where termination of the pregnancy is decided upon, and the gestation is further than 21 weeks and six days, the feticide procedure is recommended in order to ensure stillbirth. The feticide procedure entails the injection of potassium chloride directly into the fetal heart in order to ensure fetal demise. Existing literature on “feticide” and late termination of pregnancy (LTOP) owing to fetal abnormalities mostly takes a medical or psychological perspective in researching these procedures. Within the South African context, there are very few studies on feticide and LTOP, with none of these studies (to date – 8 January 2023) taking a feminist approach. This paucity of research that takes into account power relations, structural inequality and factors that affect decision-making and choice is one of the reasons that this study was undertaken. The main research question focused on in this study is: What are South African women’s experiences of feticide and late termination of pregnancy due to the presence of severe fetal abnormality, as related by the women themselves and the health service providers who perform the procedure or provide care? The sub-questions that initially drove the study were: How do the women relate their experience of the process of coming to the decision, undergoing and recovering from the procedure, and how do health service providers relate the experiences of these women? The methodological and theoretical framework employed in this research was a Feminist Social Constructionist approach to Grounded Theory. This reflexive, subjectivist, feminist lens encouraged awareness of the influence of gender, race, class and other structural and systemic factors on women’s experiences within the two healthcare systems. Data collection entailed semi-structured interviews conducted with 12 women, who had undergone feticide and LTOP procedures between one and five years prior to the interviews, in either the public or private healthcare system in South Africa. Semi-structured interviews were also conducted with 13 healthcare providers. The providers included medical specialists and participants from the fields of clinical psychology, genetic counselling and nursing and were employed in public or private healthcare in South Africa. Data relevant to public healthcare users and providers were collected from one tertiary (academic) public healthcare hospital and data regarding private healthcare users and providers were collected from across South Africa. Women’s constructions of their experiences of feticide and LTOP included stark contrasts between public and private healthcare users in South Africa, as well as women experiencing “no choice” and their voices being ignored or silenced. Healthcare providers’ constructions were frequently contradictory, referring to women as having freedom of choice and their needs largely prioritised within the healthcare system, while the providers within the public healthcare system relayed their own frustrations and emotional burden due to systemic failures. Findings from women and providers’ constructions were synthesised into a theoretical understanding of women’s experiences of feticide and LTOP in South Africa, which is grounded in, and emergent from, the data. Women’s experiences of feticide and LTOP in South Africa were conceptualised by framing the three phases of these experiences, namely the decision-making phase (I), undergoing the procedures and in-hospital recovery (phase II) and the recovery phase (III). The most prominent themes emerging in these phases included the schism between the public and private healthcare systems in South Africa, the lack of real choice women experience, as well as the silencing of women and providers with regard to feticide and LTOP. Underlying the three phases, and directly influencing the three prominent themes affecting women’s experiences, were the underlying and insidious structural inequality that undermined reproductive justice with regard to women’s decision-making, experiences of and recovery from feticide and LTOP. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2023
- Full Text:
Spatial analysis of littoral and demersal fish assemblages within the Knysna Estuary system
- Authors: Meiklejohn, Andrew Keith
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424334 , vital:72144
- Description: The Knysna Estuary is a unique system as it is the only “estuarine bay” system in the warm-temperate region of South Africa and is the largest estuary system on the southern coastline of South Africa. The Knysna Estuary has been identified as the estuary with the highest conversation priority in South Africa. The volume of research undertaken on the Knysna Estuary has led to it being rated “excellent” in terms of research productivity. However, despite this, surprisingly little work has been undertaken and published around the dynamics of fish assemblages occurring in the system, with little to no research assessing the demersal fish assemblage. The last widespread fish sampling effort that has been published was conducted in 1994, highlighting the need for an updated fish assessment with a focused sampling effort targeting both the littoral and demersal fish populations. The identification of key habitats for estuarine fish assemblages is essential for addressing estuarine conservation needs. Despite the importance of spatial data in addressing conservation planning, few estuarine studies have used spatial analyses in Geographic Information Systems (GIS) to identify conservation priority areas. Such information is critical for effective estuarine management plans. The aim of this project was to identify juvenile fish density hotspots to inform future systematic conservation planning. This study made use of two methods of sampling, seine netting to target the littoral fish assemblage and beam trawling to target demersal fish species. Two dedicated sampling trips for each sampling method were undertaken in June 2021 and March 2022 for Seine net sampling and November 2021 and March 2022 for Beam trawl sampling. Fish were identified to species level, measured (mm TL) and categorised into life history stages (i.e. settlement stage, juvenile and adult) and thereafter assigned into their various estuarine association guilds. A total of 47 species were recorded, with 42 species were caught in the seine net sampling and 24 species in the beam trawl sampling. The results from this study showed the vast extent of marine dominance in the Knysna Estuary, with marine estuarine-opportunist (MEO) species dominating catches (richness) from both sampling methods. The spatial analysis highlighted the importance of the lower “marine bay” region of the system, with the majority of estuarine guilds showing a high abundance in this region. Key fishery species and dominant fish species were identified during this study, the dominant species during the sampling effort were identified as ecologically important fish species and were dominated by adult specimens. The key fishery species sampled during this study were dominated by juvenile specimens. This highlights the role of the Knysna Estuary as a nursery area for juvenile fishery species and the contribution of the estuary to the estuarine and adjacent coastal fisheries. Key hotspots were identified for fishery species, these being the “Ashmead Channel” in the marine bay region and the “Belvidere” section of the lagoon region. Ashmead channel is sheltered backwater area while the Belvidere section is some distance from the main river channel, reducing the anthropogenic impact on these areas. The low anthropogenic utilization of these areas along with weaker water current in these regions was linked to the usage of these region by key fishery species. These areas were highlighted as important conservation hotspots with both currently not adequately protected under the current habitat sensitivity management model. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Authors: Meiklejohn, Andrew Keith
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424334 , vital:72144
- Description: The Knysna Estuary is a unique system as it is the only “estuarine bay” system in the warm-temperate region of South Africa and is the largest estuary system on the southern coastline of South Africa. The Knysna Estuary has been identified as the estuary with the highest conversation priority in South Africa. The volume of research undertaken on the Knysna Estuary has led to it being rated “excellent” in terms of research productivity. However, despite this, surprisingly little work has been undertaken and published around the dynamics of fish assemblages occurring in the system, with little to no research assessing the demersal fish assemblage. The last widespread fish sampling effort that has been published was conducted in 1994, highlighting the need for an updated fish assessment with a focused sampling effort targeting both the littoral and demersal fish populations. The identification of key habitats for estuarine fish assemblages is essential for addressing estuarine conservation needs. Despite the importance of spatial data in addressing conservation planning, few estuarine studies have used spatial analyses in Geographic Information Systems (GIS) to identify conservation priority areas. Such information is critical for effective estuarine management plans. The aim of this project was to identify juvenile fish density hotspots to inform future systematic conservation planning. This study made use of two methods of sampling, seine netting to target the littoral fish assemblage and beam trawling to target demersal fish species. Two dedicated sampling trips for each sampling method were undertaken in June 2021 and March 2022 for Seine net sampling and November 2021 and March 2022 for Beam trawl sampling. Fish were identified to species level, measured (mm TL) and categorised into life history stages (i.e. settlement stage, juvenile and adult) and thereafter assigned into their various estuarine association guilds. A total of 47 species were recorded, with 42 species were caught in the seine net sampling and 24 species in the beam trawl sampling. The results from this study showed the vast extent of marine dominance in the Knysna Estuary, with marine estuarine-opportunist (MEO) species dominating catches (richness) from both sampling methods. The spatial analysis highlighted the importance of the lower “marine bay” region of the system, with the majority of estuarine guilds showing a high abundance in this region. Key fishery species and dominant fish species were identified during this study, the dominant species during the sampling effort were identified as ecologically important fish species and were dominated by adult specimens. The key fishery species sampled during this study were dominated by juvenile specimens. This highlights the role of the Knysna Estuary as a nursery area for juvenile fishery species and the contribution of the estuary to the estuarine and adjacent coastal fisheries. Key hotspots were identified for fishery species, these being the “Ashmead Channel” in the marine bay region and the “Belvidere” section of the lagoon region. Ashmead channel is sheltered backwater area while the Belvidere section is some distance from the main river channel, reducing the anthropogenic impact on these areas. The low anthropogenic utilization of these areas along with weaker water current in these regions was linked to the usage of these region by key fishery species. These areas were highlighted as important conservation hotspots with both currently not adequately protected under the current habitat sensitivity management model. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
Spatiotemporal ecology and potential displacement of white sharks in southern Africa
- Authors: Towner, Alison
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432275 , vital:72857
- Description: Restricted access. Expected release date in 2025. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Authors: Towner, Alison
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432275 , vital:72857
- Description: Restricted access. Expected release date in 2025. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
Species diversity and distribution patterns of three freshwater fish genera in southern Africa
- Authors: Mutizwa, Tadiwa Isaac
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431896 , vital:72813
- Description: Access restricted. Expected release in 2025. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Authors: Mutizwa, Tadiwa Isaac
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431896 , vital:72813
- Description: Access restricted. Expected release in 2025. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
Status and potential of green infrastructure to support urban resilience in Zomba City, Malawi
- Authors: Likongwe, Patrick Jeremy
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431821 , vital:72806 , DOI 10.21504/10962/431821
- Description: Small and medium towns with less than one million inhabitants are regarded to be the fastest growing urban centres globally, absorbing the bulk of the urban population growth. This urban growth drives the diminishing natural capital within the urban settings, resulting in compromised ecosystem services delivery, thereby rendering urban dwellers and systems less resilient to hazards and shocks. It is known that urban resilience discourse is rooted in robust, empirical assessments of the nature, composition and distribution of urban green infrastructure. Using the concept of green infrastructure, a mechanism for the delivery of ecosystem services that are multi-functional, well connected, and that integrate the grey-green infrastructure while providing room for social inclusion, anchored the research in a small city of Zomba, Malawi, which is a fast-growing city facing natural resource and ecosystem service degradation. The research therefore was set to understand the status of urban green infrastructure in Zomba over space and time as the basis for enhancing urban resilience. This was facilitated by an understanding of the spatial and temporal quantity, quality, diversity and distribution of urban greenspaces and the composition, structure, diversity and distributional differences of urban trees within different urban greenspace classes. Further to this was an investigation on the perceptions of and preferences for urban greenspaces among the different socio-demographic groups and finally the role of residents, institutions and institutional frameworks in building urban resilience through the delivery of ecosystem services. To achieve these objectives, the study used a suite of methods. First was geographical information system and remote sensing to understand the spatial and temporal changes in greenspaces within the city in terms of quantity and distribution. Ecological methods of assessing the tree species composition, diversity, population structure and distribution were also employed. To gauge the perceptions of and preferences for urban greenspaces, a survey was done, targeting users found within the urban greenspaces plus residents that claimed to have patronised the urban greenspaces. Finally, to understand the role of nature and the relevant urban ecosystem services provided towards building urban resilience, remote sensing and key informant interviews were done to enrich the literature searches on a case study of urban community efforts involved in managing Sadzi hill to reverse ecosystem disservices versus Chiperoni hill that was not managed. A general impression of declining urban green infrastructure was verified through the study. The city has indeed lost 14 % tree cover between 1998 and 2018 due to increased housing and creation of agricultural land to support the growing urban population. The city has 168 tree species with 65 % of them being indigenous. Residential areas were dominated by exotic trees, mainly due to the abundance of exotic fruit trees like Mangifera indica. Generally, the city has a good tree diversity score but unequally distributed, with the formal residential areas, where the colonial masters settled, having more trees than the mixed and informal residential areas. Nine urban greenspace types were identified, but there was a low per capita urban greenspace area of 11.6 m2 per person, slightly above the minimum standard set by World Health Organisation. From the preferences for and perceptions of urban greenspaces, patronage to these greenspaces (treated as parks) was highest among the educated youth, a majority being from the high housing density areas where there are no urban parks. Walking to the nearest urban greenspace took more than 10 minutes for 85 % of the respondents. With the available by-laws in support for the governance of greenspaces within the city and the role of residents towards the same, restoration efforts that targeted Sadzi hill yielded positive results through reversing ecosystem disservices that were being experienced by the community members around the hill. The community enjoys several ecosystem services that have also contributed towards building their resilience to climatic and environmental hazards. The results of this study have unveiled several green infrastructure attributes that can contribute towards building urban social ecological resilience like the presence of high proportion of indigenous tree species, healthy urban forest, high proportion of fruit trees, high diversity scores, unparalleled demand for urban greenspaces for cultural and regulatory ecosystem services, the willingness to pay and work towards managing and conserving greenspaces and the social capital available from the urban communities. However, the study also unveiled several green infrastructure related attributes that if not checked will continue to undermine efforts towards building urban resilience. These included the continued drop in tree and greenspace cover, poor governance of the available public greenspaces, unequal distribution of trees and urban greenspaces, poor management of greenspaces, bare river banks, lack of park amenities and a lack of a clear strategy, policy or an urban plan that clearly outlines green infrastructure. Efforts towards addressing these will mean acknowledging the role of green infrastructure in supporting urban social ecological resilience. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2023
- Full Text:
- Authors: Likongwe, Patrick Jeremy
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431821 , vital:72806 , DOI 10.21504/10962/431821
- Description: Small and medium towns with less than one million inhabitants are regarded to be the fastest growing urban centres globally, absorbing the bulk of the urban population growth. This urban growth drives the diminishing natural capital within the urban settings, resulting in compromised ecosystem services delivery, thereby rendering urban dwellers and systems less resilient to hazards and shocks. It is known that urban resilience discourse is rooted in robust, empirical assessments of the nature, composition and distribution of urban green infrastructure. Using the concept of green infrastructure, a mechanism for the delivery of ecosystem services that are multi-functional, well connected, and that integrate the grey-green infrastructure while providing room for social inclusion, anchored the research in a small city of Zomba, Malawi, which is a fast-growing city facing natural resource and ecosystem service degradation. The research therefore was set to understand the status of urban green infrastructure in Zomba over space and time as the basis for enhancing urban resilience. This was facilitated by an understanding of the spatial and temporal quantity, quality, diversity and distribution of urban greenspaces and the composition, structure, diversity and distributional differences of urban trees within different urban greenspace classes. Further to this was an investigation on the perceptions of and preferences for urban greenspaces among the different socio-demographic groups and finally the role of residents, institutions and institutional frameworks in building urban resilience through the delivery of ecosystem services. To achieve these objectives, the study used a suite of methods. First was geographical information system and remote sensing to understand the spatial and temporal changes in greenspaces within the city in terms of quantity and distribution. Ecological methods of assessing the tree species composition, diversity, population structure and distribution were also employed. To gauge the perceptions of and preferences for urban greenspaces, a survey was done, targeting users found within the urban greenspaces plus residents that claimed to have patronised the urban greenspaces. Finally, to understand the role of nature and the relevant urban ecosystem services provided towards building urban resilience, remote sensing and key informant interviews were done to enrich the literature searches on a case study of urban community efforts involved in managing Sadzi hill to reverse ecosystem disservices versus Chiperoni hill that was not managed. A general impression of declining urban green infrastructure was verified through the study. The city has indeed lost 14 % tree cover between 1998 and 2018 due to increased housing and creation of agricultural land to support the growing urban population. The city has 168 tree species with 65 % of them being indigenous. Residential areas were dominated by exotic trees, mainly due to the abundance of exotic fruit trees like Mangifera indica. Generally, the city has a good tree diversity score but unequally distributed, with the formal residential areas, where the colonial masters settled, having more trees than the mixed and informal residential areas. Nine urban greenspace types were identified, but there was a low per capita urban greenspace area of 11.6 m2 per person, slightly above the minimum standard set by World Health Organisation. From the preferences for and perceptions of urban greenspaces, patronage to these greenspaces (treated as parks) was highest among the educated youth, a majority being from the high housing density areas where there are no urban parks. Walking to the nearest urban greenspace took more than 10 minutes for 85 % of the respondents. With the available by-laws in support for the governance of greenspaces within the city and the role of residents towards the same, restoration efforts that targeted Sadzi hill yielded positive results through reversing ecosystem disservices that were being experienced by the community members around the hill. The community enjoys several ecosystem services that have also contributed towards building their resilience to climatic and environmental hazards. The results of this study have unveiled several green infrastructure attributes that can contribute towards building urban social ecological resilience like the presence of high proportion of indigenous tree species, healthy urban forest, high proportion of fruit trees, high diversity scores, unparalleled demand for urban greenspaces for cultural and regulatory ecosystem services, the willingness to pay and work towards managing and conserving greenspaces and the social capital available from the urban communities. However, the study also unveiled several green infrastructure related attributes that if not checked will continue to undermine efforts towards building urban resilience. These included the continued drop in tree and greenspace cover, poor governance of the available public greenspaces, unequal distribution of trees and urban greenspaces, poor management of greenspaces, bare river banks, lack of park amenities and a lack of a clear strategy, policy or an urban plan that clearly outlines green infrastructure. Efforts towards addressing these will mean acknowledging the role of green infrastructure in supporting urban social ecological resilience. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2023
- Full Text:
Stimulating continuous professional development and teacher leadership in a rural Namibian school: a participatory action research
- Authors: Mario, Kangende Mebin
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424075 , vital:72121
- Description: Namibia values democratic and quality education. One way to improve quality education is by allowing teachers autonomy and offering continuous professional development (CPD) to teachers. Historically, the CPD programmes on offer in Namibia were centralised and generic, using a ‘one-size-fits-all’ approach offered as mini workshops to train teachers. In 2012, a decentralised method of school-based CPD program was initiated in schools, to give opportunities to schools to identify, plan, implement and evaluate their own professional needs. However, a recent study indicated that these initiatives have failed due to poor leadership, a lack of training and support as well as limited knowledge of principals in running CPD initiatives. Against this backdrop, my study aimed at engaging in a participatory action research process with teachers and SMT members in a rural combined school in the Kavango West region to stimulate the failed school-based CPD program and develop teacher leadership. My study therefore aligned with the international recommendations that school-based CPD be built around the notions of distributed leadership and teacher leadership (Smulyan, 2016; Hunzicker, 2018). The three-step model of change and action research developed by Kurt Lewin served as the underpinning theory for this study. The study was situated within a critical paradigm and driven by the question: “Does the involvement in participatory action research process stimulate a school-based CPD programme and develop teacher leadership?” The study involved two phases. The contextual profiling stage generated data through the analysis of documents, focus group interviews, and observation. Phase 2 engaged the participant in participatory action research to stimulate school-based CPD and develop teacher leadership. Thematic analysis supported by both inductive and deductive methods was used to analyse the data. The findings from phase one indicated that CPD was interpreted differently by the participants and confirmed that there was no CPD program in the school. Using Grant's (2017) model of teacher leadership, the findings further revealed that although teacher leadership was practised in all four zones, it was strongest in the classroom and initiated through delegated practices. Using Angelle and Dehart (2010), constraining forces included negative teachers’ attitudes, limited knowledge, skills, and confidence as well as a school culture of distrust. Phase 2 revealed that participatory action research can be a useful stimulus for school-based CPD. A tangible output from the PAR sessions was a template for the internal policy for school-based continuous teacher development. In addition, the findings from the sessions indicated the significance of supportive leadership to ensure the efficacy of school-based CPD and teacher leadership. , Thesis (MEd) -- Faculty of Education, Primary and Early Childhood Education, 2023
- Full Text:
- Authors: Mario, Kangende Mebin
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424075 , vital:72121
- Description: Namibia values democratic and quality education. One way to improve quality education is by allowing teachers autonomy and offering continuous professional development (CPD) to teachers. Historically, the CPD programmes on offer in Namibia were centralised and generic, using a ‘one-size-fits-all’ approach offered as mini workshops to train teachers. In 2012, a decentralised method of school-based CPD program was initiated in schools, to give opportunities to schools to identify, plan, implement and evaluate their own professional needs. However, a recent study indicated that these initiatives have failed due to poor leadership, a lack of training and support as well as limited knowledge of principals in running CPD initiatives. Against this backdrop, my study aimed at engaging in a participatory action research process with teachers and SMT members in a rural combined school in the Kavango West region to stimulate the failed school-based CPD program and develop teacher leadership. My study therefore aligned with the international recommendations that school-based CPD be built around the notions of distributed leadership and teacher leadership (Smulyan, 2016; Hunzicker, 2018). The three-step model of change and action research developed by Kurt Lewin served as the underpinning theory for this study. The study was situated within a critical paradigm and driven by the question: “Does the involvement in participatory action research process stimulate a school-based CPD programme and develop teacher leadership?” The study involved two phases. The contextual profiling stage generated data through the analysis of documents, focus group interviews, and observation. Phase 2 engaged the participant in participatory action research to stimulate school-based CPD and develop teacher leadership. Thematic analysis supported by both inductive and deductive methods was used to analyse the data. The findings from phase one indicated that CPD was interpreted differently by the participants and confirmed that there was no CPD program in the school. Using Grant's (2017) model of teacher leadership, the findings further revealed that although teacher leadership was practised in all four zones, it was strongest in the classroom and initiated through delegated practices. Using Angelle and Dehart (2010), constraining forces included negative teachers’ attitudes, limited knowledge, skills, and confidence as well as a school culture of distrust. Phase 2 revealed that participatory action research can be a useful stimulus for school-based CPD. A tangible output from the PAR sessions was a template for the internal policy for school-based continuous teacher development. In addition, the findings from the sessions indicated the significance of supportive leadership to ensure the efficacy of school-based CPD and teacher leadership. , Thesis (MEd) -- Faculty of Education, Primary and Early Childhood Education, 2023
- Full Text:
Storytelling through video game artworks – Twee kante van ’n storie
- Authors: Randall, Tasmin Tania
- Date: 2023-10-13
- Subjects: Colored people (South Africa) Ethnic identity , Colored people (South Africa) in art , Storytelling in art , Digital art , Browser game , Art Video games , Autoethnography , Stereotypes (Social psychology) in art , Discrimination based on hair texture , Swag
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425355 , vital:72232
- Description: This mini-thesis serves as a supporting document for my Master of Fine Art (MFA) exhibition, ‘Twee Kante van ‘n Storie’. The exhibition explores my culture and experiences as a ‘Coloured’ woman in Makhanda through storytelling. I use the term ‘Coloured’ with quotation marks to remain respectful to those who do not wish to reclaim the term. My minithesis analyses how video games as artworks can be a mode of storytelling and can encourage sociocultural awareness. In my research, I use storytelling as a tool and autoethnography as a methodology to both discuss and influence my practice. For my MFA installation, I have created a digital interactive website that uses the same language as a video game. Throughout my process, I have used two video games, That Dragon Cancer and Boet Fighter, as case studies, in order to help the building and creation of my autoethnographic art video game. My art video game explores my experiences of my culture and living in a small town. Through the creation of four fictionalised characters, which are loosely based on true life experiences and first-hand observations, I can reveal and unpack cultural experiences and biases that I have observed over the years. Each character in the game grapples with one of three prominent themes; stereotypes, ‘swagger’ and texturism. Furthermore, through using autoethnography as a methodology and the researcher as the phenomenon (Ellis, 2004: 45). This study contributes to the gap in ‘Coloured’ cultural diversities that exist outside the lens of the Western Cape experience. This is a perspective not commonly found within academia. , Thesis (MFA) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
- Authors: Randall, Tasmin Tania
- Date: 2023-10-13
- Subjects: Colored people (South Africa) Ethnic identity , Colored people (South Africa) in art , Storytelling in art , Digital art , Browser game , Art Video games , Autoethnography , Stereotypes (Social psychology) in art , Discrimination based on hair texture , Swag
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425355 , vital:72232
- Description: This mini-thesis serves as a supporting document for my Master of Fine Art (MFA) exhibition, ‘Twee Kante van ‘n Storie’. The exhibition explores my culture and experiences as a ‘Coloured’ woman in Makhanda through storytelling. I use the term ‘Coloured’ with quotation marks to remain respectful to those who do not wish to reclaim the term. My minithesis analyses how video games as artworks can be a mode of storytelling and can encourage sociocultural awareness. In my research, I use storytelling as a tool and autoethnography as a methodology to both discuss and influence my practice. For my MFA installation, I have created a digital interactive website that uses the same language as a video game. Throughout my process, I have used two video games, That Dragon Cancer and Boet Fighter, as case studies, in order to help the building and creation of my autoethnographic art video game. My art video game explores my experiences of my culture and living in a small town. Through the creation of four fictionalised characters, which are loosely based on true life experiences and first-hand observations, I can reveal and unpack cultural experiences and biases that I have observed over the years. Each character in the game grapples with one of three prominent themes; stereotypes, ‘swagger’ and texturism. Furthermore, through using autoethnography as a methodology and the researcher as the phenomenon (Ellis, 2004: 45). This study contributes to the gap in ‘Coloured’ cultural diversities that exist outside the lens of the Western Cape experience. This is a perspective not commonly found within academia. , Thesis (MFA) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
Synthesis of natural product-inspired imido and 3,5-disubstituted-1,2,4-oxadiazolo phosphonates as potential anti-malarial agents
- Authors: Chithambo, Bertha
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431637 , vital:72792
- Description: Access restricted. Expected release date in 2024. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Authors: Chithambo, Bertha
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431637 , vital:72792
- Description: Access restricted. Expected release date in 2024. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
The activity and foraging patterns of the western rock elephant shrew (Elephantulus rupestris)
- Authors: Jackson, Emily Anne
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424402 , vital:72150
- Description: The increase, and prolonged periods, of high ambient temperatures are cause for concern for small mammals living in arid areas of Southern Africa. In this study, I aimed to determine the effect of high environmental temperatures on the activity, body temperature maintenance and foraging behaviour in a population of Western rock elephant shrew, Elephantulus rupestris, in the Eastern Cape, South Africa. I found that E. rupestris maintained stable body temperatures (Tb = 37.31 °C ± 0.64) over a range of environmental temperatures (Tair = 5° to 33.9 °C), indicating their ability to remain normothermic during the heat of the day. Under cool, mild and hot air temperatures, E. rupestris were predominantly active in the morning and night, being the least active during midday. This shift in activity time, known as polyphasic activity, is common amongst Macroscelidea species and is a mechanism for escaping thermal extremes. To determine the effect of temperature on foraging behaviour, I ran giving-up density (GUD) experiments on E. rupestris under a range of environmental conditions. GUD experiments yielded no conclusive results as animals did not show a significant preference for foraging under certain thermal conditions, and rather foraged under a variety of air temperatures. Overall, E. rupestris showed risk adverse behaviour, trading-off thermoregulation with foraging and activity for self-preservation during hot periods of the day. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Authors: Jackson, Emily Anne
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424402 , vital:72150
- Description: The increase, and prolonged periods, of high ambient temperatures are cause for concern for small mammals living in arid areas of Southern Africa. In this study, I aimed to determine the effect of high environmental temperatures on the activity, body temperature maintenance and foraging behaviour in a population of Western rock elephant shrew, Elephantulus rupestris, in the Eastern Cape, South Africa. I found that E. rupestris maintained stable body temperatures (Tb = 37.31 °C ± 0.64) over a range of environmental temperatures (Tair = 5° to 33.9 °C), indicating their ability to remain normothermic during the heat of the day. Under cool, mild and hot air temperatures, E. rupestris were predominantly active in the morning and night, being the least active during midday. This shift in activity time, known as polyphasic activity, is common amongst Macroscelidea species and is a mechanism for escaping thermal extremes. To determine the effect of temperature on foraging behaviour, I ran giving-up density (GUD) experiments on E. rupestris under a range of environmental conditions. GUD experiments yielded no conclusive results as animals did not show a significant preference for foraging under certain thermal conditions, and rather foraged under a variety of air temperatures. Overall, E. rupestris showed risk adverse behaviour, trading-off thermoregulation with foraging and activity for self-preservation during hot periods of the day. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
The adoption of international financial reporting standards and foreign direct investment inflows: the moderating effect of the institutional environment in Africa
- Authors: Simbi, Chipo
- Date: 2023-10-13
- Subjects: International Financial Reporting Standards , Investments, Foreign , Institutional infrastructure , Accounting Law and legislation , Auditing Law and legislation , Generalized method of moments , Difference in differences
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/419230 , vital:71627 , DOI 10.21504/10962/419230
- Description: Globalisation has created a need for an international accounting language to facilitate the smooth flow of trade across countries. In 2003, in an effort to establish a global financial reporting language, the International Accounting Standards Board (IASB) developed a single set of high-quality accounting principles known as the International Financial Reporting Standards (IFRS). Over the last decade, several African countries have adopted IFRS, and Africa has become the second-largest adopting continent after Europe. IFRS promotes improved quality of disclosure of accounting transactions, reduces information asymmetry between preparers and users of financial information, lowers the cost of investing, and breaks down information barriers to cross-border investment. Researchers suggest many benefits of IFRS adoption for macroeconomic indicators such as Foreign Direct Investment (FDI). The reduction in information acquisition and processing costs which translates into the reduction in investment costs, has been cited by most researchers. Researchers have argued, however, that the economic benefits of IFRS in Africa depend on the strength of the institutional environment. They also argue that the Western environment in which the IFRS was developed differs from the African environment. Thus, the universal approach of the IASB may not be appropriate due to the historical, social, economic and political context of African countries. The impact of the adoption of IFRS by African countries requires further examination, particularly as a weak institutional environment confronts many African countries. Three research questions are designed for this study; (1) Is there a significant change in FDI inflows for IFRS adopters in selected African countries after the adoption? (2) Is there a significant change in FDI inflows due to the institutional environment? (3) Does the institutional environment in IFRS-adopting countries moderate the effect of IFRS on FDI in selected African countries? The present study is underpinned by the new institutional theory, the information asymmetry theory, the eclectic theory and the signalling theory, each of which provide reasons why African countries have adopted IFRS. Nine hypotheses are developed, based on the research questions, and tested using the Systems General Method of Moments and the Difference-in-Difference method. The study uses data from 26 African countries, 15 adopting and 11 non-adopting countries, over the period 1996 - 2018. First, the study establishes that the adoption of IFRS positively and significantly affects FDI inflows into the selected sample of African countries. Second, the study concludes that legal enforcement, accounting and auditing standards enforcement, and language origin positively and significantly impact FDI inflows into these countries. Legal origin, however, has a positive but insignificant association with FDI inflows. Third, legal enforcement, historical ties, accounting and auditing enforcement and the quality of the institutional environment are found to moderate the effect of IFRS adoption on FDI inflows. These results indicate that IFRS is a crucial determinant of FDI inflows into African countries, but a supportive institutional environment is needed for African countries to attract FDI inflows after adoption. The results contribute to the accounting and finance literature on FDI into African countries, and may assist the investment community to assess the institutional risk associated with investing in IFRS adopting African countries. , Thesis (PhD) -- Faculty of Commerce, Accounting, 2023
- Full Text:
- Authors: Simbi, Chipo
- Date: 2023-10-13
- Subjects: International Financial Reporting Standards , Investments, Foreign , Institutional infrastructure , Accounting Law and legislation , Auditing Law and legislation , Generalized method of moments , Difference in differences
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/419230 , vital:71627 , DOI 10.21504/10962/419230
- Description: Globalisation has created a need for an international accounting language to facilitate the smooth flow of trade across countries. In 2003, in an effort to establish a global financial reporting language, the International Accounting Standards Board (IASB) developed a single set of high-quality accounting principles known as the International Financial Reporting Standards (IFRS). Over the last decade, several African countries have adopted IFRS, and Africa has become the second-largest adopting continent after Europe. IFRS promotes improved quality of disclosure of accounting transactions, reduces information asymmetry between preparers and users of financial information, lowers the cost of investing, and breaks down information barriers to cross-border investment. Researchers suggest many benefits of IFRS adoption for macroeconomic indicators such as Foreign Direct Investment (FDI). The reduction in information acquisition and processing costs which translates into the reduction in investment costs, has been cited by most researchers. Researchers have argued, however, that the economic benefits of IFRS in Africa depend on the strength of the institutional environment. They also argue that the Western environment in which the IFRS was developed differs from the African environment. Thus, the universal approach of the IASB may not be appropriate due to the historical, social, economic and political context of African countries. The impact of the adoption of IFRS by African countries requires further examination, particularly as a weak institutional environment confronts many African countries. Three research questions are designed for this study; (1) Is there a significant change in FDI inflows for IFRS adopters in selected African countries after the adoption? (2) Is there a significant change in FDI inflows due to the institutional environment? (3) Does the institutional environment in IFRS-adopting countries moderate the effect of IFRS on FDI in selected African countries? The present study is underpinned by the new institutional theory, the information asymmetry theory, the eclectic theory and the signalling theory, each of which provide reasons why African countries have adopted IFRS. Nine hypotheses are developed, based on the research questions, and tested using the Systems General Method of Moments and the Difference-in-Difference method. The study uses data from 26 African countries, 15 adopting and 11 non-adopting countries, over the period 1996 - 2018. First, the study establishes that the adoption of IFRS positively and significantly affects FDI inflows into the selected sample of African countries. Second, the study concludes that legal enforcement, accounting and auditing standards enforcement, and language origin positively and significantly impact FDI inflows into these countries. Legal origin, however, has a positive but insignificant association with FDI inflows. Third, legal enforcement, historical ties, accounting and auditing enforcement and the quality of the institutional environment are found to moderate the effect of IFRS adoption on FDI inflows. These results indicate that IFRS is a crucial determinant of FDI inflows into African countries, but a supportive institutional environment is needed for African countries to attract FDI inflows after adoption. The results contribute to the accounting and finance literature on FDI into African countries, and may assist the investment community to assess the institutional risk associated with investing in IFRS adopting African countries. , Thesis (PhD) -- Faculty of Commerce, Accounting, 2023
- Full Text:
The androgenic and anabolic effects of pine pollen on Nile tilapia (Oreochromis niloticus)
- Authors: Abaho, Ivan
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431615 , vital:72790
- Description: Access restricted. Expected release date in 2025 , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Authors: Abaho, Ivan
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431615 , vital:72790
- Description: Access restricted. Expected release date in 2025 , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
The application of statistical classification to predict sovereign default
- Authors: Vele, Rendani
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424563 , vital:72164
- Description: When considering sovereign loans, it is imperative for a financial institution to have a good understanding of the sovereign they are transacting with. Defaults can occur if proper evaluation steps are not considered. To aid in the prediction of potential sovereign defaults, financial institutions, together with grading companies, quantify the risk associated with issuing a loan to a sovereign by developing sovereign default early warning systems (EWS). Various classification models are considered in this study to develop sovereign default EWS. These models are the binary logit, probit, Bayesian additive regression trees, and artificial neural networks. This study investigates the predictive performance of the various classification techniques. Sovereign information is not readily available, so missing data techniques are considered in order to counter the data availability issue. Sovereign defaults are rare, which results in an imbalance in the distribution of the binary dependent variable. To assess data sets with such characteristics, metrics for imbalanced data are considered for model performance comparison. From the findings, the Bayesian additive regression technique generated better results than the other techniques when considering a basic data analysis. Moreover when cross-validation was considered, the neural network technique performed best. In addition, regional models had better results than the global model when considering model predictive capability. The significance of this study is to develop sovereign default prediction models using various classification techniques focused on enhancing previous literature and analysis through the application of Bayesian additive regression trees. , Thesis (MSc) -- Faculty of Science, Statistics, 2023
- Full Text:
- Authors: Vele, Rendani
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424563 , vital:72164
- Description: When considering sovereign loans, it is imperative for a financial institution to have a good understanding of the sovereign they are transacting with. Defaults can occur if proper evaluation steps are not considered. To aid in the prediction of potential sovereign defaults, financial institutions, together with grading companies, quantify the risk associated with issuing a loan to a sovereign by developing sovereign default early warning systems (EWS). Various classification models are considered in this study to develop sovereign default EWS. These models are the binary logit, probit, Bayesian additive regression trees, and artificial neural networks. This study investigates the predictive performance of the various classification techniques. Sovereign information is not readily available, so missing data techniques are considered in order to counter the data availability issue. Sovereign defaults are rare, which results in an imbalance in the distribution of the binary dependent variable. To assess data sets with such characteristics, metrics for imbalanced data are considered for model performance comparison. From the findings, the Bayesian additive regression technique generated better results than the other techniques when considering a basic data analysis. Moreover when cross-validation was considered, the neural network technique performed best. In addition, regional models had better results than the global model when considering model predictive capability. The significance of this study is to develop sovereign default prediction models using various classification techniques focused on enhancing previous literature and analysis through the application of Bayesian additive regression trees. , Thesis (MSc) -- Faculty of Science, Statistics, 2023
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The CODESRIA debate on academic and intellectual freedom in Africa: the role and responsibility of African intellectuals
- Authors: Cabe, Loyiso
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/431463 , vital:72774
- Description: According to Fagunwa (2011), intellectuals serve as the glue that binds societies together and serve as the foundation upon which new civilizations are created and dismantled. The Council for the Development of Social Science Research in Africa (CODESRIA) of 1990 entrusted intellectuals with crucial transformative tasks (roles) and responsibilities in Africa. This study explores the transformational roles and responsibilities of African intellectuals in neo-liberal and neo-colonial Africa as well as how academic freedom must be understood by African academics in accordance with the present debate on academic freedom in South Africa, which was fueled by Nattrass (2020) paper. The primary premise of this study is that academic freedom in Africa today is viewed differently than it was during the CODESRIA meeting on academic freedom in 1990, and that this is because of African intellectuals not carrying out their roles and responsibilities in Africa. In CODESRIA 1990, academic freedom referred to an academic’s unrestricted, yet responsible, right to pursue their academic interests (CODESRIA 1990; Kampala Declaration 1990). African academics now understand academic freedom to be merely their own freedom, unrelated to their responsibility to use it ethically and professionally. Hence, for them, academic freedom entails the freedom to express oneself without restrictions or fear of criticism (Chachage, 2008; Nattrass, 2020b; Esso, and Long, 2020). Looking at this current misinterpretation of academic freedom, the 1990 CODESRIA meeting is a good reference point to the debate on academic freedom in Africa and role and responsibility of African intellectuals. This is because, it was where academic freedom and the role and responsibility of African intellectuals in Africa was professionally conceptualized. Thus, this study reviews the 1990 CODESRIA debate to understand the role and responsibility of African intellectuals. This study utilizes two theories, Social Constructivism Theory and the Social Responsibility Theory, to explain the position it has taken on the subject at hand. Thus, these theories provide an umbrella and a point of departure for understanding the context and dynamics of the ongoing conflict between academic freedom and social responsibility in South Africa's higher education institutions. , Thesis (MSocSci) -- Faculty of Humanities, Political and International Studies, 2023
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- Authors: Cabe, Loyiso
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/431463 , vital:72774
- Description: According to Fagunwa (2011), intellectuals serve as the glue that binds societies together and serve as the foundation upon which new civilizations are created and dismantled. The Council for the Development of Social Science Research in Africa (CODESRIA) of 1990 entrusted intellectuals with crucial transformative tasks (roles) and responsibilities in Africa. This study explores the transformational roles and responsibilities of African intellectuals in neo-liberal and neo-colonial Africa as well as how academic freedom must be understood by African academics in accordance with the present debate on academic freedom in South Africa, which was fueled by Nattrass (2020) paper. The primary premise of this study is that academic freedom in Africa today is viewed differently than it was during the CODESRIA meeting on academic freedom in 1990, and that this is because of African intellectuals not carrying out their roles and responsibilities in Africa. In CODESRIA 1990, academic freedom referred to an academic’s unrestricted, yet responsible, right to pursue their academic interests (CODESRIA 1990; Kampala Declaration 1990). African academics now understand academic freedom to be merely their own freedom, unrelated to their responsibility to use it ethically and professionally. Hence, for them, academic freedom entails the freedom to express oneself without restrictions or fear of criticism (Chachage, 2008; Nattrass, 2020b; Esso, and Long, 2020). Looking at this current misinterpretation of academic freedom, the 1990 CODESRIA meeting is a good reference point to the debate on academic freedom in Africa and role and responsibility of African intellectuals. This is because, it was where academic freedom and the role and responsibility of African intellectuals in Africa was professionally conceptualized. Thus, this study reviews the 1990 CODESRIA debate to understand the role and responsibility of African intellectuals. This study utilizes two theories, Social Constructivism Theory and the Social Responsibility Theory, to explain the position it has taken on the subject at hand. Thus, these theories provide an umbrella and a point of departure for understanding the context and dynamics of the ongoing conflict between academic freedom and social responsibility in South Africa's higher education institutions. , Thesis (MSocSci) -- Faculty of Humanities, Political and International Studies, 2023
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The complexities of transfer pricing methods and the role of advance pricing agreements and tax audits in addressing disputes
- Authors: Ndou, Wavhudi
- Date: 2023-10-13
- Subjects: Transfer pricing Taxation Law and legislation South Africa , Advance pricing agreement , Double taxation , Arms-length transactions , Tax auditing , Advance tax ruling , Organisation for Economic Co-operation and Development , United Nations , World Bank
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419631 , vital:71661
- Description: Base erosion and profit shifting is defined as the use of tax planning strategies by multinational enterprises, often through exploiting gaps and mismatches between the countries in which they operate (OECD, 2021: p. 1). Multinational enterprises exploit these gaps through the use of transfer pricing. Goods and services are exchanged between connected persons or associated enterprises at prices that do not reflect their arm’s length price, in order to shift profits from high tax to low tax jurisdictions. In terms of section 31 of the Income Tax Act, transactions between connected persons or associated enterprises must be reflected at their arm’s length price. Transfer pricing has become an issue due to the difficulties in determining an appropriate arm’s length price. Disputes arise between a taxpayer and a tax administration on the methods to use to determine an appropriate transfer price. The use of Advance Pricing Agreements prevents these disputes from arising and provides tax certainty on the treatment of transactions for both the taxpayer and the tax administration. While the OECD recommends the use of Advance Pricing Agreements as a method to prevent disputes from arising, the OECD also argued that if a country has the resources to conduct an audit, an Advance Pricing Agreement will not lead to increased revenue collection. The research therefore analyses the problems faced in determining an appropriate arm's length price and compares the role that Advance Pricing Agreements and audits play in addressing transfer pricing issues. The possible role of Advance Tax Rulings is also explored, but they are found not to be suitable, except for the most simple transactions. The research applies a legal interpretative, doctrinal research methodology and a qualitative research method. The data comprised of relevant South African tax legislation, OECD Guidelines, the World Bank Handbook, and the UN Manual, together with the writings of acknowledged experts in the field. The study establishes that a proper functioning audit system is crucial to increasing revenue collection once a country implements an Advance Pricing Agreement. The research therefore recommends the adoption of Advance Pricing Agreements in South Africa as a dispute prevention measure. , Thesis (MCom) -- Faculty of Commerce, Accounting, 2023
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- Authors: Ndou, Wavhudi
- Date: 2023-10-13
- Subjects: Transfer pricing Taxation Law and legislation South Africa , Advance pricing agreement , Double taxation , Arms-length transactions , Tax auditing , Advance tax ruling , Organisation for Economic Co-operation and Development , United Nations , World Bank
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419631 , vital:71661
- Description: Base erosion and profit shifting is defined as the use of tax planning strategies by multinational enterprises, often through exploiting gaps and mismatches between the countries in which they operate (OECD, 2021: p. 1). Multinational enterprises exploit these gaps through the use of transfer pricing. Goods and services are exchanged between connected persons or associated enterprises at prices that do not reflect their arm’s length price, in order to shift profits from high tax to low tax jurisdictions. In terms of section 31 of the Income Tax Act, transactions between connected persons or associated enterprises must be reflected at their arm’s length price. Transfer pricing has become an issue due to the difficulties in determining an appropriate arm’s length price. Disputes arise between a taxpayer and a tax administration on the methods to use to determine an appropriate transfer price. The use of Advance Pricing Agreements prevents these disputes from arising and provides tax certainty on the treatment of transactions for both the taxpayer and the tax administration. While the OECD recommends the use of Advance Pricing Agreements as a method to prevent disputes from arising, the OECD also argued that if a country has the resources to conduct an audit, an Advance Pricing Agreement will not lead to increased revenue collection. The research therefore analyses the problems faced in determining an appropriate arm's length price and compares the role that Advance Pricing Agreements and audits play in addressing transfer pricing issues. The possible role of Advance Tax Rulings is also explored, but they are found not to be suitable, except for the most simple transactions. The research applies a legal interpretative, doctrinal research methodology and a qualitative research method. The data comprised of relevant South African tax legislation, OECD Guidelines, the World Bank Handbook, and the UN Manual, together with the writings of acknowledged experts in the field. The study establishes that a proper functioning audit system is crucial to increasing revenue collection once a country implements an Advance Pricing Agreement. The research therefore recommends the adoption of Advance Pricing Agreements in South Africa as a dispute prevention measure. , Thesis (MCom) -- Faculty of Commerce, Accounting, 2023
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The contentious relationship between feminist scholarship and university sexual violence policies: 1980-2021
- Authors: Roberts, Lily May
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425267 , vital:72224
- Description: This thesis tracks the historically contentious relationship between feminist scholarship and university sexual violence policies. It examines the rise of the managerial university in South Africa, and the overlapping development of sexual violence policies through feminist activism from the early 1990s. Through an examination of the sexual violence policies of the University of Cape Town, the University of the Witwatersrand, Rhodes University, Stellenbosch University, and the University of the Western Cape, this thesis argues that these policies are aimed at ‘managing’ the process of reporting, rather than dismantling the broader structures – both within the university and society as a whole – that lead to and enable sexual violence. In this way, sexual violence policies are governed by a managerial discourse, limiting the possibility of addressing the dismantling of structures and discourses that perpetuate sexual violence, which, as I argue, is fundamentally opposed to the intellectual and political project of feminist scholarship from which these sexual violence policies initially emerged. However, this thesis also argues that feminist scholarship is not immune to the influence of managerialism, as discourses of efficiency and effectiveness have shaped Gender and Women’s Studies, where feminist scholarship is often located. I use the #RUReferenceList protests that drew on black feminist scholarship and came under managerial control as an example of the contentious relationship between managerialism and feminist activism. , Thesis (MA) -- Faculty of Humanities, History, 2023
- Full Text:
- Authors: Roberts, Lily May
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425267 , vital:72224
- Description: This thesis tracks the historically contentious relationship between feminist scholarship and university sexual violence policies. It examines the rise of the managerial university in South Africa, and the overlapping development of sexual violence policies through feminist activism from the early 1990s. Through an examination of the sexual violence policies of the University of Cape Town, the University of the Witwatersrand, Rhodes University, Stellenbosch University, and the University of the Western Cape, this thesis argues that these policies are aimed at ‘managing’ the process of reporting, rather than dismantling the broader structures – both within the university and society as a whole – that lead to and enable sexual violence. In this way, sexual violence policies are governed by a managerial discourse, limiting the possibility of addressing the dismantling of structures and discourses that perpetuate sexual violence, which, as I argue, is fundamentally opposed to the intellectual and political project of feminist scholarship from which these sexual violence policies initially emerged. However, this thesis also argues that feminist scholarship is not immune to the influence of managerialism, as discourses of efficiency and effectiveness have shaped Gender and Women’s Studies, where feminist scholarship is often located. I use the #RUReferenceList protests that drew on black feminist scholarship and came under managerial control as an example of the contentious relationship between managerialism and feminist activism. , Thesis (MA) -- Faculty of Humanities, History, 2023
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The development and op timisation of a Theiler’s murine encephalomyelitis virus antiviral assay
- Authors: Naidoo, Urisha Tirah
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424677 , vital:72174
- Description: Picornaviruses belong to the Picornaviridae family which are one of the largest and most diverse family of RNA viruses that cause a broad spectrum of infections in both humans and animals. These diseases range from severe infections such as poliomyelitis, meningitis, myocarditis to mild illnesses such as the common cold. Picornavirus outbreaks are a worldwide threat as they are continuously occurring. A recent outbreak of foot-and-mouth disease caused by a picornavirus occurred in South Africa, resulting in a temporary ban on the movement of cattle. Currently, the FDA has not approved any antiviral drugs against this virus, increasing the urgency for identifying effective antivirals. Picornaviruses have similar genomes and capsid organisation as such, those that are non-hazardous to humans can be used as a model system. A Theiler’s murine encephalomyelitis virus (TMEV) strain GDVII and Baby Hamster Kidney fibroblasts (BHK-21 cells) was used as a replication system to develop and optimise a medium-throughput antiviral screening assay. The TMEV GDVII replication system in BHK-21 cells was validated, and preliminary experiments were performed that were necessary for the development of the TMEV GDVII antiviral assay. This was achieved by conducting a CPE assay to visually monitor the onset and development of CPE induced by TMEV GDVII. Plaque assays accurately quantified the number of infectious virus particles required for calculating the MOI in downstream experiments. Lastly, indirect immunofluorescence and Western blot analysis detected the expression of viral proteins using previously generated antibodies against the TMEV GDVII VP1 capsid and 2C protein, thereby confirming infection in BHK-21 cells. The development of robust and reproducible assays is an essential component in antiviral drug discovery. Therefore, the confirmed replication system was then used as a foundation to develop a medium-throughput CPE-based TMEV GDVII antiviral assay whereby the parameters were optimised to produce one of high quality. Firstly, the quantitation of viral-induced CPE was examined and confirmed in a 96-well plate using resazurin as a cell viability indicator. Each parameter was tested at varying conditions, and the optimal was concluded as 2 % FBS in the assay media, a 15 000 cells/well seeding density, infecting the cells with TMEV GDVII at an MOI of 0.00625 and measuring resazurin at an endpoint of 72 hpi. Furthermore, the parameters were ii validated by calculating the Z’- factor, which consistently produced scores above 0.5, indicative of a reliable, robust, reproducible antiviral assay. Currently, there are no inhibitors against TMEV GDVII that have been reported or confirmed in cell lines, animal models or clinical trials. Therefore, once the optimal assay parameters were selected, it presented an opportunity to assess whether potential compounds, including itraconazole (ITZ) and dipyridamole (DIP), possessed antiviral activity that could firstly, be utilised as a control inhibitor when screening compounds against TMEV GDVII and secondly, contribute to research on this virus. Additionally, the previously produced anti-TMEV GDVII capsid antibody was shown to neutralise viral infection and was also included as a potential control. The sensitivity of the cells towards DMSO, a solution in which the compounds were solubilised, was first investigated. It was found that concentrations above 1 % are toxic to the cells; as such, the final DMSO concentrations were always kept below 1 % when screening compounds. Lastly, the generation of dose-response curves aided in the conclusion that the antibody was the most suitable control inhibitor as it displayed potent antiviral activity and no cytotoxicity towards the cells. In contrast, ITZ and DIP did not possess effective antiviral action and were toxic to cells at high concentrations. Finally, after all the components of the medium-throughput TMEV GDVII antiviral assay were identified, it was possible to screen 24 compounds from a coumarin and marine natural product library for cell cytotoxicity and antiviral activity. After generating dose-response curves, it was concluded that no compound effectively inhibited virus-induced CPE, and most were toxic to cells at relatively high concentrations. In conclusion, this is the first study that describes the development and optimisation of a robust medium-throughput CPE-based antiviral assay that has immense potential to screen other libraries of compounds for antiviral activity against TMEV GDVII. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Authors: Naidoo, Urisha Tirah
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424677 , vital:72174
- Description: Picornaviruses belong to the Picornaviridae family which are one of the largest and most diverse family of RNA viruses that cause a broad spectrum of infections in both humans and animals. These diseases range from severe infections such as poliomyelitis, meningitis, myocarditis to mild illnesses such as the common cold. Picornavirus outbreaks are a worldwide threat as they are continuously occurring. A recent outbreak of foot-and-mouth disease caused by a picornavirus occurred in South Africa, resulting in a temporary ban on the movement of cattle. Currently, the FDA has not approved any antiviral drugs against this virus, increasing the urgency for identifying effective antivirals. Picornaviruses have similar genomes and capsid organisation as such, those that are non-hazardous to humans can be used as a model system. A Theiler’s murine encephalomyelitis virus (TMEV) strain GDVII and Baby Hamster Kidney fibroblasts (BHK-21 cells) was used as a replication system to develop and optimise a medium-throughput antiviral screening assay. The TMEV GDVII replication system in BHK-21 cells was validated, and preliminary experiments were performed that were necessary for the development of the TMEV GDVII antiviral assay. This was achieved by conducting a CPE assay to visually monitor the onset and development of CPE induced by TMEV GDVII. Plaque assays accurately quantified the number of infectious virus particles required for calculating the MOI in downstream experiments. Lastly, indirect immunofluorescence and Western blot analysis detected the expression of viral proteins using previously generated antibodies against the TMEV GDVII VP1 capsid and 2C protein, thereby confirming infection in BHK-21 cells. The development of robust and reproducible assays is an essential component in antiviral drug discovery. Therefore, the confirmed replication system was then used as a foundation to develop a medium-throughput CPE-based TMEV GDVII antiviral assay whereby the parameters were optimised to produce one of high quality. Firstly, the quantitation of viral-induced CPE was examined and confirmed in a 96-well plate using resazurin as a cell viability indicator. Each parameter was tested at varying conditions, and the optimal was concluded as 2 % FBS in the assay media, a 15 000 cells/well seeding density, infecting the cells with TMEV GDVII at an MOI of 0.00625 and measuring resazurin at an endpoint of 72 hpi. Furthermore, the parameters were ii validated by calculating the Z’- factor, which consistently produced scores above 0.5, indicative of a reliable, robust, reproducible antiviral assay. Currently, there are no inhibitors against TMEV GDVII that have been reported or confirmed in cell lines, animal models or clinical trials. Therefore, once the optimal assay parameters were selected, it presented an opportunity to assess whether potential compounds, including itraconazole (ITZ) and dipyridamole (DIP), possessed antiviral activity that could firstly, be utilised as a control inhibitor when screening compounds against TMEV GDVII and secondly, contribute to research on this virus. Additionally, the previously produced anti-TMEV GDVII capsid antibody was shown to neutralise viral infection and was also included as a potential control. The sensitivity of the cells towards DMSO, a solution in which the compounds were solubilised, was first investigated. It was found that concentrations above 1 % are toxic to the cells; as such, the final DMSO concentrations were always kept below 1 % when screening compounds. Lastly, the generation of dose-response curves aided in the conclusion that the antibody was the most suitable control inhibitor as it displayed potent antiviral activity and no cytotoxicity towards the cells. In contrast, ITZ and DIP did not possess effective antiviral action and were toxic to cells at high concentrations. Finally, after all the components of the medium-throughput TMEV GDVII antiviral assay were identified, it was possible to screen 24 compounds from a coumarin and marine natural product library for cell cytotoxicity and antiviral activity. After generating dose-response curves, it was concluded that no compound effectively inhibited virus-induced CPE, and most were toxic to cells at relatively high concentrations. In conclusion, this is the first study that describes the development and optimisation of a robust medium-throughput CPE-based antiviral assay that has immense potential to screen other libraries of compounds for antiviral activity against TMEV GDVII. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text: