Shaping self through ceramic sculpture: representing anxiety in the rural black queer experience
- Authors: Phaliso, Phila Vuyiseka
- Date: 2024-10-11
- Subjects: Ceramic sculpture 21st century , Ceramic sculpture Social aspects , Sexual minorities, Black Social conditions , Anxiety , Rural conditions
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/466082 , vital:76683
- Description: I am a ceramic sculptor. I make use of clay that I have sourced from Joza, the Makhanda location, and Cofimvaba in a rural area called Magwala. I process this clay and then use it to create a visual and tangible representation of the anxiety I experience as a queer black woman living in South Africa. Unongayindoda is a word that has been used by isiXhosa speaking people in my village to call me ever since I was a child. This is a word that I have chosen to own, in much the same way that some people have chosen to own the word “queer.” My experience of being unongayindoda has had an impact on my mental health, and the process of digging clay, processing it for use and then using it to create my work has become very therapeutic for me. My work’s primary aim is to explore the use of clay as a representative embodiment of anxiety in my work as a rural black queer sculptor who identifies as unongayindoda. The thesis component of my work is a qualitative study informed by autoethnography, practice and art-based research. , Thesis (MA) -- Faculty of Humanities, Fine Art, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Phaliso, Phila Vuyiseka
- Date: 2024-10-11
- Subjects: Ceramic sculpture 21st century , Ceramic sculpture Social aspects , Sexual minorities, Black Social conditions , Anxiety , Rural conditions
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/466082 , vital:76683
- Description: I am a ceramic sculptor. I make use of clay that I have sourced from Joza, the Makhanda location, and Cofimvaba in a rural area called Magwala. I process this clay and then use it to create a visual and tangible representation of the anxiety I experience as a queer black woman living in South Africa. Unongayindoda is a word that has been used by isiXhosa speaking people in my village to call me ever since I was a child. This is a word that I have chosen to own, in much the same way that some people have chosen to own the word “queer.” My experience of being unongayindoda has had an impact on my mental health, and the process of digging clay, processing it for use and then using it to create my work has become very therapeutic for me. My work’s primary aim is to explore the use of clay as a representative embodiment of anxiety in my work as a rural black queer sculptor who identifies as unongayindoda. The thesis component of my work is a qualitative study informed by autoethnography, practice and art-based research. , Thesis (MA) -- Faculty of Humanities, Fine Art, 2024
- Full Text:
- Date Issued: 2024-10-11
Ukuma njenge ndoda: the making of Xhosa masculinities in Mthatha, Eastern Cape
- Authors: Silosini, Tandokazi
- Date: 2024-10-11
- Subjects: Xhosa (African people) South Africa Mthatha , Men, Black South Africa Mthatha , Men Identity , Masculinity , Gender-based violence
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/466317 , vital:76717
- Description: This study examines how young men construct their masculine identities in daily life through the collection of activities that happen throughout young men's lives in Mthatha, Eastern Cape. The aim of the research is to examine how black men construct their identity as men. It seeks to examine the everyday ways in which young men speak of their masculinity, how they understand themselves in relation to women and the causes of gender-based and sexual violence in South Africa. The study conceptualises Xhosa masculinities and manhood within the framework of masculinist violence and the state. It demonstrates the intersection of manhood violence and the state within the discipline of international relations which is characterised by ideas of state security and war. Interviews with Xhosa men in Mthatha illuminated that boys are raised to be men who stand, articulated as ukuma njenge ndoda (standing up as a man), for themselves, family and community. Ukuma operates as an assertion and protection of self, a demonstration of independence and being self-sustaining. It importantly speaks to the gendered division of labour where over and above standing up for oneself, it is a man’s duty and responsibility “ukumela izinto zekhaya” – to stand up for his home and family. This thesis shows that the different forms that ukuma carry with them expectations of dominance and control or at least maintain the appearance of it. Ultimately, the concept of ukuma serves as a way to legitimise the use of force or violence in certain instances where men feel that an act of violence constitutes ukuzimela (standing up for himself) or ukumela ikhaya (standing up for his family). The masculinising of this duty implicates not only the men it is bestowed upon the women and children who are the ones supposedly protected and provided for. , Thesis (MSocSci) -- Faculty of Humanities, Political and International Studies, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Silosini, Tandokazi
- Date: 2024-10-11
- Subjects: Xhosa (African people) South Africa Mthatha , Men, Black South Africa Mthatha , Men Identity , Masculinity , Gender-based violence
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/466317 , vital:76717
- Description: This study examines how young men construct their masculine identities in daily life through the collection of activities that happen throughout young men's lives in Mthatha, Eastern Cape. The aim of the research is to examine how black men construct their identity as men. It seeks to examine the everyday ways in which young men speak of their masculinity, how they understand themselves in relation to women and the causes of gender-based and sexual violence in South Africa. The study conceptualises Xhosa masculinities and manhood within the framework of masculinist violence and the state. It demonstrates the intersection of manhood violence and the state within the discipline of international relations which is characterised by ideas of state security and war. Interviews with Xhosa men in Mthatha illuminated that boys are raised to be men who stand, articulated as ukuma njenge ndoda (standing up as a man), for themselves, family and community. Ukuma operates as an assertion and protection of self, a demonstration of independence and being self-sustaining. It importantly speaks to the gendered division of labour where over and above standing up for oneself, it is a man’s duty and responsibility “ukumela izinto zekhaya” – to stand up for his home and family. This thesis shows that the different forms that ukuma carry with them expectations of dominance and control or at least maintain the appearance of it. Ultimately, the concept of ukuma serves as a way to legitimise the use of force or violence in certain instances where men feel that an act of violence constitutes ukuzimela (standing up for himself) or ukumela ikhaya (standing up for his family). The masculinising of this duty implicates not only the men it is bestowed upon the women and children who are the ones supposedly protected and provided for. , Thesis (MSocSci) -- Faculty of Humanities, Political and International Studies, 2024
- Full Text:
- Date Issued: 2024-10-11
Attitudes and achievement in statistics: a meta-analytic and functional near-infrared spectroscopy approach
- Authors: Wagenaar, Emma Kate
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/435490 , vital:73162
- Description: Statistics anxiety describes the extensive worry and apprehension that students may experience when faced with statistics content as part of their university curriculums. Student’s perfunctory disposition towards statistics has been indicated to negatively affect performance outcomes in statistics courses. Two meta-analyses were conducted to investigate the relationship between statistics anxiety and achievement in statistics. The first meta-analysis was inclusive of 22 studies investigating the relationship attitudes towards statistics and achievement, whilst the second meta-analysis focused on the relationship, primary amongst Psychology students. Student’s attitudes towards statistics were measured using the Survey of Attitudes Towards Statistics (SATS), whilst achievement in statistics courses was quantified using different outcome measures. Finding from the meta-analysis were supplemented by cortical mapping of the neural correlates of statistical reasoning using functional near-infrared spectroscopy (fNIRS). Results from the meta-analysis indicated a small significant relationship between university students’ Affect, r = 0.28, Value, r = 0.22 and Difficulty, r = 0.18, and subsequent achievement in statistics courses. A medium significant relationship between Cognitive Competence, r = 0.31, and achievement was also noted. Findings from the second meta-analysis, indicated a medium, significant relationship between Affect, r = 0.32, and Cognitive Competence, r = 0.35, and achievement. Moreover, a small significant relationship was found between Value, r = 0.24, and Difficulty, r = 0.23, in relation to achievement in statistics courses. Case study analysis of the neural correlates of statistics reasoning revealed varied signal quality findings of cortical mapping of the neural correlates of statistics in the dorsolateral prefrontal cortex (DLPFC). Moreover, seed-based correlation analysis indicated cortical activation of the dorsolateral prefrontal cortex paired with diverse prefrontal regions. Recommendations from the study include improvements to the fNIRS research design and the inclusion of larger samples to investigate the cortical mapping of the DLPFC in relation to statistics reasoning and statistics anxiety. , Thesis (MA) -- Faculty of Humanities, Psychology, 2024
- Full Text:
- Date Issued: 2024-04-04
- Authors: Wagenaar, Emma Kate
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/435490 , vital:73162
- Description: Statistics anxiety describes the extensive worry and apprehension that students may experience when faced with statistics content as part of their university curriculums. Student’s perfunctory disposition towards statistics has been indicated to negatively affect performance outcomes in statistics courses. Two meta-analyses were conducted to investigate the relationship between statistics anxiety and achievement in statistics. The first meta-analysis was inclusive of 22 studies investigating the relationship attitudes towards statistics and achievement, whilst the second meta-analysis focused on the relationship, primary amongst Psychology students. Student’s attitudes towards statistics were measured using the Survey of Attitudes Towards Statistics (SATS), whilst achievement in statistics courses was quantified using different outcome measures. Finding from the meta-analysis were supplemented by cortical mapping of the neural correlates of statistical reasoning using functional near-infrared spectroscopy (fNIRS). Results from the meta-analysis indicated a small significant relationship between university students’ Affect, r = 0.28, Value, r = 0.22 and Difficulty, r = 0.18, and subsequent achievement in statistics courses. A medium significant relationship between Cognitive Competence, r = 0.31, and achievement was also noted. Findings from the second meta-analysis, indicated a medium, significant relationship between Affect, r = 0.32, and Cognitive Competence, r = 0.35, and achievement. Moreover, a small significant relationship was found between Value, r = 0.24, and Difficulty, r = 0.23, in relation to achievement in statistics courses. Case study analysis of the neural correlates of statistics reasoning revealed varied signal quality findings of cortical mapping of the neural correlates of statistics in the dorsolateral prefrontal cortex (DLPFC). Moreover, seed-based correlation analysis indicated cortical activation of the dorsolateral prefrontal cortex paired with diverse prefrontal regions. Recommendations from the study include improvements to the fNIRS research design and the inclusion of larger samples to investigate the cortical mapping of the DLPFC in relation to statistics reasoning and statistics anxiety. , Thesis (MA) -- Faculty of Humanities, Psychology, 2024
- Full Text:
- Date Issued: 2024-04-04
Performance evaluation of baseline-dependent window functions with several weighing functions
- Authors: Vanqa, Kamvulethu
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/435850 , vital:73206
- Description: Radio interferometric data volume is exponentially increasing with the potential to cause slow processing and data storage issues for radio observations recorded at high time and frequency resolutions. This necessitates that a sort of data compression is imposed. The conventional method to compress the data is averaging across time and frequency. However, this results in amplitude loss and source distortion at the edges of the field of view. To reduce amplitude loss and source distortion, baseline-dependent window functions (BDWFs) are proposed in theliterature. BDWFs are visibility data compression methods using window functions to retainthe signals within a field of interest (FoI) and to suppress signals outside this FoI. However,BDWFs are used with window functions as discussed in the signal processing field without any optimisation. This thesis evaluates the performance of BDWFs and then proposes to use machine learning with gradient descent to optimize the window functions employed in BDWFs. Results show that the convergence of the objective function is limited due to the band-limited nature of the window functions in the Fourier space. BDWFs performance is also investigated and discussed using several weighting schemes. Results show that there exists an optimal parameter tuning (not necessarily unique) that suggests an optimal combination of BDWFs and density sampling. With this, ∼ 4 % smearing is observed within the FoI, and ∼ 80 % source suppression is achieved outside the FoI using the MeerKAT telescope at 1.4 GHz, sampled at 1 s and 184.3 kHz then averaged with BDWFs to achieve a compression factor of 4 in time and 3 in frequency. , Thesis (MA) -- Faculty of Science, Mathematics, 2024
- Full Text:
- Date Issued: 2024-04-04
- Authors: Vanqa, Kamvulethu
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/435850 , vital:73206
- Description: Radio interferometric data volume is exponentially increasing with the potential to cause slow processing and data storage issues for radio observations recorded at high time and frequency resolutions. This necessitates that a sort of data compression is imposed. The conventional method to compress the data is averaging across time and frequency. However, this results in amplitude loss and source distortion at the edges of the field of view. To reduce amplitude loss and source distortion, baseline-dependent window functions (BDWFs) are proposed in theliterature. BDWFs are visibility data compression methods using window functions to retainthe signals within a field of interest (FoI) and to suppress signals outside this FoI. However,BDWFs are used with window functions as discussed in the signal processing field without any optimisation. This thesis evaluates the performance of BDWFs and then proposes to use machine learning with gradient descent to optimize the window functions employed in BDWFs. Results show that the convergence of the objective function is limited due to the band-limited nature of the window functions in the Fourier space. BDWFs performance is also investigated and discussed using several weighting schemes. Results show that there exists an optimal parameter tuning (not necessarily unique) that suggests an optimal combination of BDWFs and density sampling. With this, ∼ 4 % smearing is observed within the FoI, and ∼ 80 % source suppression is achieved outside the FoI using the MeerKAT telescope at 1.4 GHz, sampled at 1 s and 184.3 kHz then averaged with BDWFs to achieve a compression factor of 4 in time and 3 in frequency. , Thesis (MA) -- Faculty of Science, Mathematics, 2024
- Full Text:
- Date Issued: 2024-04-04
A case study of role conflict experienced by middle management during organizational change
- Authors: Sepeng, Mugabe
- Date: 2023-10-13
- Subjects: Role conflict , Change management , Middle managers , Middle management , ISO 9001 Standard Implementation of
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419189 , vital:71624
- Description: This research investigation is based on continuous improvement changes arising from - and related to - ISO 9001 implementation at Sundays River Citrus Company (SRCC), which is one of the biggest packers, marketers, and exporters of citrus fruit in South Africa. The Board of SRCC adopted ISO 9001 to ensure organizational efficiency and sustainability while improving quality control, customer service, teamwork and leadership. However, research indicates not all organizations that have Implemented ISO 9001 realize the intended benefits. While no research was available on the citrus agriculture industry, research in the tourism industry indicates that not only did some companies not realize the expected benefits, but also incurred substantial investment costs. It is estimated that approximately thirty to ninety percent of change initiatives fail to meet their objectives, and research studies also indicate that middle managers play a critical role that can influence the outcomes of a change project. However, Balogun (2003) indicates that middle managers play a complex role and are exposed to role conflict, which can influence the outcomes of change initiatives. In this context, this research study aimed to investigate the role conflicts experienced by middle managers during the process of an ISO 9001 continuous improvement change. The study draws on role theory, applying it to their management of change. The following role conflict types were investigated: (1) intra-sender conflict, (2) inter-sender role conflict, (3) inter-role conflict, (4) role ambiguity and (5) role strain. The research approach is qualitative, and has adopted a post-positivist paradigm, utilizing a deductive qualitative method. The study adopted a case study approach. Data was gathered mainly from interviews and supported by organizational documents. Semi structured interviews were conducted with questions formulated through the use of the coding manual (See Appendix C) to ensure alignment of data collection with the research propositions derived from literature. A deductive thematic analysis method was used to analyze the interview data. The research findings confirmed that during continuous improvement change, as middle managers strived to satisfy the incompatible expectations of role senders (mainly senior and junior managers), they experienced the five role conflict types. The study findings also indicate that middle managers experience conflicts due to the incompatible expectations of other role senders such as quality and marketing departments. The findings suggest that middle managers are managing these conflicts, but notes that they do require some assistance and support from senior management. The study concludes with managerial and research recommendations. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Sepeng, Mugabe
- Date: 2023-10-13
- Subjects: Role conflict , Change management , Middle managers , Middle management , ISO 9001 Standard Implementation of
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419189 , vital:71624
- Description: This research investigation is based on continuous improvement changes arising from - and related to - ISO 9001 implementation at Sundays River Citrus Company (SRCC), which is one of the biggest packers, marketers, and exporters of citrus fruit in South Africa. The Board of SRCC adopted ISO 9001 to ensure organizational efficiency and sustainability while improving quality control, customer service, teamwork and leadership. However, research indicates not all organizations that have Implemented ISO 9001 realize the intended benefits. While no research was available on the citrus agriculture industry, research in the tourism industry indicates that not only did some companies not realize the expected benefits, but also incurred substantial investment costs. It is estimated that approximately thirty to ninety percent of change initiatives fail to meet their objectives, and research studies also indicate that middle managers play a critical role that can influence the outcomes of a change project. However, Balogun (2003) indicates that middle managers play a complex role and are exposed to role conflict, which can influence the outcomes of change initiatives. In this context, this research study aimed to investigate the role conflicts experienced by middle managers during the process of an ISO 9001 continuous improvement change. The study draws on role theory, applying it to their management of change. The following role conflict types were investigated: (1) intra-sender conflict, (2) inter-sender role conflict, (3) inter-role conflict, (4) role ambiguity and (5) role strain. The research approach is qualitative, and has adopted a post-positivist paradigm, utilizing a deductive qualitative method. The study adopted a case study approach. Data was gathered mainly from interviews and supported by organizational documents. Semi structured interviews were conducted with questions formulated through the use of the coding manual (See Appendix C) to ensure alignment of data collection with the research propositions derived from literature. A deductive thematic analysis method was used to analyze the interview data. The research findings confirmed that during continuous improvement change, as middle managers strived to satisfy the incompatible expectations of role senders (mainly senior and junior managers), they experienced the five role conflict types. The study findings also indicate that middle managers experience conflicts due to the incompatible expectations of other role senders such as quality and marketing departments. The findings suggest that middle managers are managing these conflicts, but notes that they do require some assistance and support from senior management. The study concludes with managerial and research recommendations. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
- Date Issued: 2023-10-13
A second skin: investigating the role of dress in identity formation
- Featherstone, Juanito Romario
- Authors: Featherstone, Juanito Romario
- Date: 2023-10-13
- Subjects: Identity (Psychology) in art , Clothing and dress in art , Clothing and dress Social aspects , Clothing and dress Psychological aspects , Self South Africa Makhanda
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425322 , vital:72229
- Description: This thesis is a secondary component to an artistic practice-led process and as such, is guided by my own artistic practice in that way. In this body of work, I use myself as the main character or protagonist for the artworks that I have created. However, both the thesis and the exhibition also respond to social issues of identity beyond the personal and examines the construction of identity in a South African, and more specifically Makhanda context, as that is the larger context in which I am situated. The work itself is inspired by memories and experiences of feeling uncomfortable in my own (first) skin, and how I found that comfort in my second skin (dress). My professional art practice and my thesis are based on the concept of clothes as a second skin for human beings, specifically observing the ways in which we utilise dress to construct and express our identities. As such, this thesis is an attempt at understanding the relationship between clothes and the body through the lens of identity politics. Through the topics and artworks discussed in visual and textual analysis, this thesis intends to unpack the properties of dress as a complex medium individuals can utilise as a tool to construct their identity. This is partially achieved through the exploration of my own personal experiences of dress and of the spaces that shaped and mediated the construction of identity. Lastly, it is an attempt to understand the experiences of dress in parallel to the experience of the body/self, which consists of the world within and the one outside. , Thesis (MFA) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Featherstone, Juanito Romario
- Date: 2023-10-13
- Subjects: Identity (Psychology) in art , Clothing and dress in art , Clothing and dress Social aspects , Clothing and dress Psychological aspects , Self South Africa Makhanda
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425322 , vital:72229
- Description: This thesis is a secondary component to an artistic practice-led process and as such, is guided by my own artistic practice in that way. In this body of work, I use myself as the main character or protagonist for the artworks that I have created. However, both the thesis and the exhibition also respond to social issues of identity beyond the personal and examines the construction of identity in a South African, and more specifically Makhanda context, as that is the larger context in which I am situated. The work itself is inspired by memories and experiences of feeling uncomfortable in my own (first) skin, and how I found that comfort in my second skin (dress). My professional art practice and my thesis are based on the concept of clothes as a second skin for human beings, specifically observing the ways in which we utilise dress to construct and express our identities. As such, this thesis is an attempt at understanding the relationship between clothes and the body through the lens of identity politics. Through the topics and artworks discussed in visual and textual analysis, this thesis intends to unpack the properties of dress as a complex medium individuals can utilise as a tool to construct their identity. This is partially achieved through the exploration of my own personal experiences of dress and of the spaces that shaped and mediated the construction of identity. Lastly, it is an attempt to understand the experiences of dress in parallel to the experience of the body/self, which consists of the world within and the one outside. , Thesis (MFA) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
- Date Issued: 2023-10-13
Analysing equity and ethical dimensions of water governance challenges in the lower section of the upper Vaal River catchment, Gauteng, South Africa
- Authors: Tavengwa, Noleen Shamiso
- Date: 2023-10-13
- Subjects: Water governance , Water-supply South Africa Vaal River Watershed , Water-supply Management Moral and ethical aspects , Water-supply Law and legislation , Water Pollution South Africa Vaal River Watershed
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424199 , vital:72132
- Description: Poor water governance practices have been identified as one of the root causes of water problems confronting the South African water sector. This is evident in the lower section of the Upper Vaal River Catchment, where ineffective implementation of the regulatory measures has resulted in multiple incidents of illegal discharge of effluent from municipal wastewater treatment works, industrial and mining activities. Pollution and deterioration of water quality is a major challenge in the catchment; the Vaal River is severely polluted beyond acceptable standards and impacts negatively on other water users who have legitimate rights to the water resources. Pollution not only affects human activities and use, but also has negative impacts on ecological health and functionality. Poor water governance practices raise ethical implications for the rights to water for both social and ecological components. Although many water governance challenges in South Africa have implications that border on values and ethics, the relationship between these concepts has hardly been explored. In order to contribute towards filling this gap, this study explores water governance challenges and their ethical implications, and then analyse the equity dimensions of key water challenges among institutional actors in the lower section of the Upper Vaal WMA, Gauteng. The study uses a qualitative research approach which involves several methods of data collection: document analysis, workshops, focus group discussions, key informant interviews and participant observation. The data collected were analysed using thematic analysis, and then applied an ethical framework to distil ethical implications of the identified water governance challenges. There are five water governance challenges that were identified, which are i) failure in the implementation of water legislation and regulations, ii) ineffective leadership and management, iii) cooperative governance and poor accountability, iv) decentralisation and ineffective participation, and v) finance, infrastructure, and technical capacity. The deterioration of water quality and pollution due to ineffective implementation of the regulatory system has ethical implications towards protection of the ecological system and sustainable management of the water resources for the present and future generation. Ineffective implementation of the regulatory measure also raises the issue of distributive equity between different water users and between current and future users. These implications are critical particularly when viewed from the perspective of systemic-relational ethical approach which posit that in social-ecological systems, all components ought to be treated with equal regards, and their inherent worth respected in order to maintain the unity of the SES. The idea of equal regards to the inherent worth of the component implies due respect, in ways that do not undermine the integrity of the entire system. The challenges identified in the system suggest that i) the right of the ecological system to water is undermined due to anthropogenic activities, which may in the long term undermine the functionality of the entire SES; ii) the right of the margined to access to water of the right quality is also undermined, and pollution costs is externalised. These are matters of ethics that thus deserved attention in policy and management considerations. The study analysed equity dimensions (distributive and procedural), targeting the key institutional water users (i.e., mines, industries, agriculture, municipalities, and the wastewater treatment works) in the lower section of the Upper Vaal River Catchment as equity candidates due to their activities that significantly impact the environment and the water resources. The cost of pollution caused by mining activities, industrial activities and the wastewater treatment works is externalised to other users who are not responsible for the pollution. In this regard study identified key drivers that raise concerns linked to distributive equity, which are ) pollution and water quality deterioration, ii) the legacies of mining activities, and iii) poor infrastructure maintenance, vandalism, and theft. Identifying these key drivers of distributive equity concerns is critical in ensuring that the water governance processes are designed in a way that stakeholders and actors reliant on water resources within the catchment have equitable and fair access without the effects of externalised costs from other actors. The identified water governance challenges in the catchment all borders on ethics, thus an ethical framework is crucial in tackling water related problems. The principles of ethics can be used as guidelines to decision-making process for the management and governance of water resources in South Africa. Therefore, implementing and incorporating principles of the systemic-relational ethics into policy making and water resources management will yield sustainable, efficient, and equitable use and management of water resources. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Tavengwa, Noleen Shamiso
- Date: 2023-10-13
- Subjects: Water governance , Water-supply South Africa Vaal River Watershed , Water-supply Management Moral and ethical aspects , Water-supply Law and legislation , Water Pollution South Africa Vaal River Watershed
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424199 , vital:72132
- Description: Poor water governance practices have been identified as one of the root causes of water problems confronting the South African water sector. This is evident in the lower section of the Upper Vaal River Catchment, where ineffective implementation of the regulatory measures has resulted in multiple incidents of illegal discharge of effluent from municipal wastewater treatment works, industrial and mining activities. Pollution and deterioration of water quality is a major challenge in the catchment; the Vaal River is severely polluted beyond acceptable standards and impacts negatively on other water users who have legitimate rights to the water resources. Pollution not only affects human activities and use, but also has negative impacts on ecological health and functionality. Poor water governance practices raise ethical implications for the rights to water for both social and ecological components. Although many water governance challenges in South Africa have implications that border on values and ethics, the relationship between these concepts has hardly been explored. In order to contribute towards filling this gap, this study explores water governance challenges and their ethical implications, and then analyse the equity dimensions of key water challenges among institutional actors in the lower section of the Upper Vaal WMA, Gauteng. The study uses a qualitative research approach which involves several methods of data collection: document analysis, workshops, focus group discussions, key informant interviews and participant observation. The data collected were analysed using thematic analysis, and then applied an ethical framework to distil ethical implications of the identified water governance challenges. There are five water governance challenges that were identified, which are i) failure in the implementation of water legislation and regulations, ii) ineffective leadership and management, iii) cooperative governance and poor accountability, iv) decentralisation and ineffective participation, and v) finance, infrastructure, and technical capacity. The deterioration of water quality and pollution due to ineffective implementation of the regulatory system has ethical implications towards protection of the ecological system and sustainable management of the water resources for the present and future generation. Ineffective implementation of the regulatory measure also raises the issue of distributive equity between different water users and between current and future users. These implications are critical particularly when viewed from the perspective of systemic-relational ethical approach which posit that in social-ecological systems, all components ought to be treated with equal regards, and their inherent worth respected in order to maintain the unity of the SES. The idea of equal regards to the inherent worth of the component implies due respect, in ways that do not undermine the integrity of the entire system. The challenges identified in the system suggest that i) the right of the ecological system to water is undermined due to anthropogenic activities, which may in the long term undermine the functionality of the entire SES; ii) the right of the margined to access to water of the right quality is also undermined, and pollution costs is externalised. These are matters of ethics that thus deserved attention in policy and management considerations. The study analysed equity dimensions (distributive and procedural), targeting the key institutional water users (i.e., mines, industries, agriculture, municipalities, and the wastewater treatment works) in the lower section of the Upper Vaal River Catchment as equity candidates due to their activities that significantly impact the environment and the water resources. The cost of pollution caused by mining activities, industrial activities and the wastewater treatment works is externalised to other users who are not responsible for the pollution. In this regard study identified key drivers that raise concerns linked to distributive equity, which are ) pollution and water quality deterioration, ii) the legacies of mining activities, and iii) poor infrastructure maintenance, vandalism, and theft. Identifying these key drivers of distributive equity concerns is critical in ensuring that the water governance processes are designed in a way that stakeholders and actors reliant on water resources within the catchment have equitable and fair access without the effects of externalised costs from other actors. The identified water governance challenges in the catchment all borders on ethics, thus an ethical framework is crucial in tackling water related problems. The principles of ethics can be used as guidelines to decision-making process for the management and governance of water resources in South Africa. Therefore, implementing and incorporating principles of the systemic-relational ethics into policy making and water resources management will yield sustainable, efficient, and equitable use and management of water resources. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2023
- Full Text:
- Date Issued: 2023-10-13
Application of in vitro release testing (IVRT) to assess “sameness”/differences of topical clotrimazole formulations
- Wellington, Hannah Margaret Mary
- Authors: Wellington, Hannah Margaret Mary
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419599 , vital:71658
- Description: Embargoed. Possible release date early 2025 pending publications. , Thesis (MSC Pharm) -- Faculty of Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Wellington, Hannah Margaret Mary
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419599 , vital:71658
- Description: Embargoed. Possible release date early 2025 pending publications. , Thesis (MSC Pharm) -- Faculty of Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-13
Changing lenses: the problems and potential of liberalism in South Africa
- Authors: Songelwa, Chuma
- Date: 2023-10-13
- Subjects: Mills, Charles W (Charles Wade) , The Racial Contract , Liberalism South Africa , South Africa Politics and government 1994- , Political culture South Africa , Imperialism South Africa , Post-apartheid era South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425283 , vital:72226
- Description: This thesis explores liberal and hybrid approaches to peacebuilding and their decisiveness in building sustainable peace in Sierra Leone. Contemporary peacebuilding interventions have been dominated by liberal peacebuilding, also known as liberal state-building. Post-conflict states have been transforming to replicate liberal states due to assumptions of liberal states being more peaceful and less likely to fall into conflict again than non-liberal states. There is growing criticism regarding the effectiveness of this approach as its initiatives have not always translated to sustainable peace. This failure is attributed to its minimal inclusion or exclusion of local actors in the peacebuilding process as well as its application of standardised approaches in complex contexts. In response to these shortfalls, international peacebuilding scholars propose an alternative approach that would combine the liberal and the local to produce a hybrid peace, which is inclusive and context-specific. This thesis tests the decisiveness of these approaches by examining the successful peacebuilding process in Sierra Leone. It then concludes that the peacebuilding interventions of Sierra Leone demonstrate how liberal peacebuilding initiatives have little or limited success when conducted without the inclusion of local actors. However, when local actors are included in the peace-building process to make meaningful contributions (hybrid peacebuilding), peacebuilding initiatives can have a much larger impact on society. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Songelwa, Chuma
- Date: 2023-10-13
- Subjects: Mills, Charles W (Charles Wade) , The Racial Contract , Liberalism South Africa , South Africa Politics and government 1994- , Political culture South Africa , Imperialism South Africa , Post-apartheid era South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425283 , vital:72226
- Description: This thesis explores liberal and hybrid approaches to peacebuilding and their decisiveness in building sustainable peace in Sierra Leone. Contemporary peacebuilding interventions have been dominated by liberal peacebuilding, also known as liberal state-building. Post-conflict states have been transforming to replicate liberal states due to assumptions of liberal states being more peaceful and less likely to fall into conflict again than non-liberal states. There is growing criticism regarding the effectiveness of this approach as its initiatives have not always translated to sustainable peace. This failure is attributed to its minimal inclusion or exclusion of local actors in the peacebuilding process as well as its application of standardised approaches in complex contexts. In response to these shortfalls, international peacebuilding scholars propose an alternative approach that would combine the liberal and the local to produce a hybrid peace, which is inclusive and context-specific. This thesis tests the decisiveness of these approaches by examining the successful peacebuilding process in Sierra Leone. It then concludes that the peacebuilding interventions of Sierra Leone demonstrate how liberal peacebuilding initiatives have little or limited success when conducted without the inclusion of local actors. However, when local actors are included in the peace-building process to make meaningful contributions (hybrid peacebuilding), peacebuilding initiatives can have a much larger impact on society. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
Comparison of the metabolic physiology of exploited and unexploited populations of red roman (Chrysoblephus laticeps) along the south coast of South Africa
- Authors: Nabani, Xolani Prince
- Date: 2023-10-13
- Subjects: Chrysoblephus laticeps , Marine fishes Climatic factors South Africa , Marine fishes Physiology South Africa , Marine fishes Metabolism , Respirometry , Marine protected area , Evolutionary impact of fishing
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424358 , vital:72146
- Description: Anthropogenic-induced climate change and exploitation pose threat to many marine fishes on which a vast majority of people around the world depend. Rapid changes in sea surface temperature have a direct impact on the physiology of ectothermic organisms such as fish, potentially resulting in changes to population distribution, abundance, and demographics. In the face of climate change, the impacts of increasing temperature variability on fish populations may be exacerbated by exploitation. Understanding how the resilience of exploited populations is affected by climate change is critical to predict how fishes will respond in the future. This study aimed to augment our knowledge on the impact of exploitation and thermal variability on fishes by comparing the thermal physiology of an exploited and unexploited population of the resident, reef-dwelling, Chrysoblephus laticeps. Twenty live fish were collected from the exploited, Cape St Francis and 18 fish from the unexploited, Goukamma Marine Protected Area and transported to the laboratory. The metabolic performance, in terms of standard metabolic rate (SMR), maximum metabolic rate (MMR) and aerobic scope (AS) of individual C. laticeps were estimated repeatedly at 10 ℃, 16 °C and 21 °C. Linear mixed effects models were used to examine the relationship between temperature, population, and metabolic rate and a ‘cvequality’ test analysis was used to compare the variance structure of the metabolic rate regression model for each population. Overall, the findings of this study show that Chrysoblephus laticeps from the unexploited population maintains a significantly higher aerobic scope (AS) across all temperature treatments (10, 16 and 21 ℃) when compared with those from the exploited population. In addition, the maximum metabolic rate (MMR) of individuals from the unexploited population was significantly higher than that of individuals from the exploited population, but there was no evidence to suggest that variability was significantly different between the populations. On the other hand, the individuals from an exploited population had a significantly higher standard metabolic rate (SMR) at high temperatures of 21 ℃, while the unexploited population had a low SMR at these high temperatures, but a high SMR at 10 ℃. Despite these differences there was no significant variation in the SMR between the two populations. The findings of this study confirm previous work on different exploited and unexploited populations of C. laticeps and together these findings suggest that hook and line exploitation lead to reduced physiological phenotypic diversity and reduced physiological performance in exploited fish populations. These findings emphasise the importance of incorporating the iii physiological information to develop viable fisheries management tools in the context of climate change. This study also highlights the effectiveness of MPAs in conserving highperformance physiological phenotypes to maintain phenotypic diversity in fish populations. Future research should aim to evaluate the efficacy of existing MPAs in preserving the physiological diversity of important hook and line fisheries species, while fisheries managers should consider augmenting their approaches through the incorporation of well-designed MPA’s to promote physiological diversity. This will be critical to advance the development of sustainable management practices, not only in a South African context but globally, where oceanic and coastal environmental conditions are expected to rapidly change in the future. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Nabani, Xolani Prince
- Date: 2023-10-13
- Subjects: Chrysoblephus laticeps , Marine fishes Climatic factors South Africa , Marine fishes Physiology South Africa , Marine fishes Metabolism , Respirometry , Marine protected area , Evolutionary impact of fishing
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424358 , vital:72146
- Description: Anthropogenic-induced climate change and exploitation pose threat to many marine fishes on which a vast majority of people around the world depend. Rapid changes in sea surface temperature have a direct impact on the physiology of ectothermic organisms such as fish, potentially resulting in changes to population distribution, abundance, and demographics. In the face of climate change, the impacts of increasing temperature variability on fish populations may be exacerbated by exploitation. Understanding how the resilience of exploited populations is affected by climate change is critical to predict how fishes will respond in the future. This study aimed to augment our knowledge on the impact of exploitation and thermal variability on fishes by comparing the thermal physiology of an exploited and unexploited population of the resident, reef-dwelling, Chrysoblephus laticeps. Twenty live fish were collected from the exploited, Cape St Francis and 18 fish from the unexploited, Goukamma Marine Protected Area and transported to the laboratory. The metabolic performance, in terms of standard metabolic rate (SMR), maximum metabolic rate (MMR) and aerobic scope (AS) of individual C. laticeps were estimated repeatedly at 10 ℃, 16 °C and 21 °C. Linear mixed effects models were used to examine the relationship between temperature, population, and metabolic rate and a ‘cvequality’ test analysis was used to compare the variance structure of the metabolic rate regression model for each population. Overall, the findings of this study show that Chrysoblephus laticeps from the unexploited population maintains a significantly higher aerobic scope (AS) across all temperature treatments (10, 16 and 21 ℃) when compared with those from the exploited population. In addition, the maximum metabolic rate (MMR) of individuals from the unexploited population was significantly higher than that of individuals from the exploited population, but there was no evidence to suggest that variability was significantly different between the populations. On the other hand, the individuals from an exploited population had a significantly higher standard metabolic rate (SMR) at high temperatures of 21 ℃, while the unexploited population had a low SMR at these high temperatures, but a high SMR at 10 ℃. Despite these differences there was no significant variation in the SMR between the two populations. The findings of this study confirm previous work on different exploited and unexploited populations of C. laticeps and together these findings suggest that hook and line exploitation lead to reduced physiological phenotypic diversity and reduced physiological performance in exploited fish populations. These findings emphasise the importance of incorporating the iii physiological information to develop viable fisheries management tools in the context of climate change. This study also highlights the effectiveness of MPAs in conserving highperformance physiological phenotypes to maintain phenotypic diversity in fish populations. Future research should aim to evaluate the efficacy of existing MPAs in preserving the physiological diversity of important hook and line fisheries species, while fisheries managers should consider augmenting their approaches through the incorporation of well-designed MPA’s to promote physiological diversity. This will be critical to advance the development of sustainable management practices, not only in a South African context but globally, where oceanic and coastal environmental conditions are expected to rapidly change in the future. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
COVID19 and accountability in South Africa: legislation, ethics and disaster risk management
- Authors: Chapman, Emma Deidre
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419565 , vital:71655
- Description: Embargoed. Possible release in 2026 pending publication. , Thesis (MSC Pharm) -- Faculty of Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Chapman, Emma Deidre
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419565 , vital:71655
- Description: Embargoed. Possible release in 2026 pending publication. , Thesis (MSC Pharm) -- Faculty of Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-13
Enhancement of the electrocatalytic activity of phthalocyanines through the reduction in symmetry and conjugation to detonation nanodiamonds
- Authors: Ncwane, Lunathi
- Date: 2023-10-13
- Subjects: Phthalocyanines , Electrocatalysis , Nanodiamonds , Hydrazine
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424541 , vital:72162
- Description: This thesis reports on the synthesis of novel phthalocynines tetrakis[(benzo[d]thiazol-2ylthio)phthalocyaninato]cobalt(II)chloride (complex 1) and tris(2-(ethylthio)benzo[d]thiazole)2-(phthalocyanine-9-ylthio)propionate cobalt(II) chloride (complex 2). The complexes are combined with DNDs via different techniques such as π-π stacking, covalent linkage and sequential modification on glassy carbon electrode. The synthesized MPcs and conjugates were characterized using UV-visible, mass, Fourier transform infrared, and Raman spectroscopies as well as transmission electron microscopy and dynamic light scattering. Combining MPcs with DNDs sought to improve electrooxidation of hydrazine. The electrochemical studies were conducted using cyclic voltammetry, chronocoloumetry, electrochemical impedance spectroscopy and chronoamperometry. Hydrazine was utilized as an analyte of interest, due to its mutagenic and carcinogenic effects. Glassy carbon electrodes (GCE) were modified using drop and dry method. The conjugation via covalent linkage proved to be the best way of enhancing electrocatalytic properties. Since it performed better in terms of limit of detection (0.33 μM), even though catalytic rate and sensitivity are not the highest. , Thesis (MSc) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Ncwane, Lunathi
- Date: 2023-10-13
- Subjects: Phthalocyanines , Electrocatalysis , Nanodiamonds , Hydrazine
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424541 , vital:72162
- Description: This thesis reports on the synthesis of novel phthalocynines tetrakis[(benzo[d]thiazol-2ylthio)phthalocyaninato]cobalt(II)chloride (complex 1) and tris(2-(ethylthio)benzo[d]thiazole)2-(phthalocyanine-9-ylthio)propionate cobalt(II) chloride (complex 2). The complexes are combined with DNDs via different techniques such as π-π stacking, covalent linkage and sequential modification on glassy carbon electrode. The synthesized MPcs and conjugates were characterized using UV-visible, mass, Fourier transform infrared, and Raman spectroscopies as well as transmission electron microscopy and dynamic light scattering. Combining MPcs with DNDs sought to improve electrooxidation of hydrazine. The electrochemical studies were conducted using cyclic voltammetry, chronocoloumetry, electrochemical impedance spectroscopy and chronoamperometry. Hydrazine was utilized as an analyte of interest, due to its mutagenic and carcinogenic effects. Glassy carbon electrodes (GCE) were modified using drop and dry method. The conjugation via covalent linkage proved to be the best way of enhancing electrocatalytic properties. Since it performed better in terms of limit of detection (0.33 μM), even though catalytic rate and sensitivity are not the highest. , Thesis (MSc) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-10-13
Enteric microbial responses to host hyperthermia in southern African insectivorous bats: a test of thermal co-adaptation
- Authors: Hunter, Amy Alison
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424391 , vital:72149
- Description: Embargoed. Expected release date 2025. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Hunter, Amy Alison
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424391 , vital:72149
- Description: Embargoed. Expected release date 2025. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
Evaluating liberal and hybrid approaches to peacebuilding : the case of Sierra Leone
- Authors: Sitole, Sivuyile
- Date: 2023-10-13
- Subjects: Peace-building Sierra Leone , Sierra Leone Politics and government 1961- , Nation-building , Postwar reconstruction Sierra Leone
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425278 , vital:72225
- Description: This thesis explores liberal and hybrid approaches to peacebuilding and their decisiveness in building sustainable peace in Sierra Leone. Contemporary peacebuilding interventions have been dominated by liberal peacebuilding, also known as liberal state-building. Post-conflict states have been transforming to replicate liberal states due to assumptions of liberal states being more peaceful and less likely to fall into conflict again than non-liberal states. There is growing criticism regarding the effectiveness of this approach as its initiatives have not always translated to sustainable peace. This failure is attributed to its minimal inclusion or exclusion of local actors in the peacebuilding process as well as its application of standardised approaches in complex contexts. In response to these shortfalls, international peacebuilding scholars propose an alternative approach that would combine the liberal and the local to produce a hybrid peace, which is inclusive and context-specific. This thesis tests the decisiveness of these approaches by examining the successful peacebuilding process in Sierra Leone. It then concludes that the peacebuilding interventions of Sierra Leone demonstrate how liberal peacebuilding initiatives have little or limited success when conducted without the inclusion of local actors. However, when local actors are included in the peace-building process to make meaningful contributions (hybrid peacebuilding), peacebuilding initiatives can have a much larger impact on society. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Sitole, Sivuyile
- Date: 2023-10-13
- Subjects: Peace-building Sierra Leone , Sierra Leone Politics and government 1961- , Nation-building , Postwar reconstruction Sierra Leone
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425278 , vital:72225
- Description: This thesis explores liberal and hybrid approaches to peacebuilding and their decisiveness in building sustainable peace in Sierra Leone. Contemporary peacebuilding interventions have been dominated by liberal peacebuilding, also known as liberal state-building. Post-conflict states have been transforming to replicate liberal states due to assumptions of liberal states being more peaceful and less likely to fall into conflict again than non-liberal states. There is growing criticism regarding the effectiveness of this approach as its initiatives have not always translated to sustainable peace. This failure is attributed to its minimal inclusion or exclusion of local actors in the peacebuilding process as well as its application of standardised approaches in complex contexts. In response to these shortfalls, international peacebuilding scholars propose an alternative approach that would combine the liberal and the local to produce a hybrid peace, which is inclusive and context-specific. This thesis tests the decisiveness of these approaches by examining the successful peacebuilding process in Sierra Leone. It then concludes that the peacebuilding interventions of Sierra Leone demonstrate how liberal peacebuilding initiatives have little or limited success when conducted without the inclusion of local actors. However, when local actors are included in the peace-building process to make meaningful contributions (hybrid peacebuilding), peacebuilding initiatives can have a much larger impact on society. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
Examining the expenditures and retention of money of recreational fishing along the Wild Coast, South Africa
- Authors: Pyle, Michael Jonathan
- Date: 2023-10-13
- Subjects: Ecotourism South Africa , Sustainable fisheries South Africa , Wild Coast Region , Small-scale fisheries Economic aspects South Africa , Socioeconomic development , Leakage
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419673 , vital:71665
- Description: Developing countries and rural communities rely heavily on the ocean for food, transport, and the sustainability of their livelihoods. While the economics of small-scale fisheries in rural areas have received much attention, there is generally less information on the economic contributions from recreational fisheries in these areas. South Africa’s marine recreational fishery is large and contributes to a significant amount of economic activity. However, the retention of money from recreational fishing activities in local rural economies is unknown and thus the potential developmental benefits from this sector remain unquantified. This study examined the economic contributions from recreational fishing along the Wild Coast and retention of expenditures within the local economy. A total of 109 face-to-face economic surveys were administered during the peak recreational fishing season in December 2021. Based on the results, recreational fishing in the Wild Coast has the ability to generate R 415 446 098 in economic activity annually, however only 9.5% of this is retained within local coastal economies, which diminishes the economic contributions of the fishery to the Wild Coast region. Expenditures on items stemming from the informal collection and selling of bait and seafood, domestic work and guiding were the highest locally retained expenditures within the region. 98% of all bait and seafood was harvested and sold by local gillies, with 2% being bought through hotels (n=109). The total direct economic contribution in terms of informal harvesting was estimated at R 16 077 711 for 2021 (n= 9 601). The identification of these contributions can be used to provide recommendations for local economic development strategies which can support the recreational fishery while uplifting coastal communities that should be benefitting more from the activity. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Pyle, Michael Jonathan
- Date: 2023-10-13
- Subjects: Ecotourism South Africa , Sustainable fisheries South Africa , Wild Coast Region , Small-scale fisheries Economic aspects South Africa , Socioeconomic development , Leakage
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419673 , vital:71665
- Description: Developing countries and rural communities rely heavily on the ocean for food, transport, and the sustainability of their livelihoods. While the economics of small-scale fisheries in rural areas have received much attention, there is generally less information on the economic contributions from recreational fisheries in these areas. South Africa’s marine recreational fishery is large and contributes to a significant amount of economic activity. However, the retention of money from recreational fishing activities in local rural economies is unknown and thus the potential developmental benefits from this sector remain unquantified. This study examined the economic contributions from recreational fishing along the Wild Coast and retention of expenditures within the local economy. A total of 109 face-to-face economic surveys were administered during the peak recreational fishing season in December 2021. Based on the results, recreational fishing in the Wild Coast has the ability to generate R 415 446 098 in economic activity annually, however only 9.5% of this is retained within local coastal economies, which diminishes the economic contributions of the fishery to the Wild Coast region. Expenditures on items stemming from the informal collection and selling of bait and seafood, domestic work and guiding were the highest locally retained expenditures within the region. 98% of all bait and seafood was harvested and sold by local gillies, with 2% being bought through hotels (n=109). The total direct economic contribution in terms of informal harvesting was estimated at R 16 077 711 for 2021 (n= 9 601). The identification of these contributions can be used to provide recommendations for local economic development strategies which can support the recreational fishery while uplifting coastal communities that should be benefitting more from the activity. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2023
- Full Text:
- Date Issued: 2023-10-13
Exploring grade 8 teachers’ code-switching in teaching orthographic drawing in the Khomas Educational Region, Namibia
- Authors: Iita, Gabriel
- Date: 2023-10-13
- Subjects: Code switching (Linguistics) , Orthographic projection Study and teaching (Secondary) Namibia , English-medium instruction Namibia , Language and education , Social justice and education
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424041 , vital:72118
- Description: Studies in learner English proficiency in Namibia have shown that a considerable number of learners in primary and high schools have low proficiency. Naturally, this will be problematic for both learners and teachers who operate under a policy that dictates that from Grade 4 upwards, English is the medium of instruction in government schools. Literature has shown a general bias towards English as a medium of instruction from both the Namibian government and Namibian parents, despite the broader level of low English proficiency among learners. Research reviewed within this study has outlined the multiple benefits of code-switching for both learners and teachers. In fact, a recent study on the perceptions of code-switching in classrooms among Namibian learners indicated a positive attitude towards code-switching as a learning tool. Grade 8 Technical Drawing classes tend to be challenging due to the complexity and novelty of some of the concepts and terminologies used when teaching the subject. This makes it particularly difficult for learners whose first language is not English. Learners struggle to understand and make meaning of the concepts and objects used in Orthographic Drawing. Code-switching has been seen as a beneficial pedagogical tool. The study was therefore conducted to explore the Grade 8 teachers’ code-switching when teaching Orthographic Drawing in the Khomas educational region, Namibia. The study used the Matrix Language Frame Model by Myers-Scotton as the theoretical framework which focuses on two crucial language aspects of participating in code-switching and the matrix and embedded language, which guided this study. The qualitative approach employed a case study design which was used to gain first-hand experience in the Technical Drawing classrooms. Semi-structured interviews and an observation checklist were the research instruments that were used to generate data on the use of code-switching in Orthographic Drawing. Two schools, two Technical Drawing classes with 40 learners and two teachers in the Khomas region, Namibia were conveniently and purposively sampled. The data were analysed using coding, descriptive statistics and thematic data analysis. The primary and secondary results indicate that code-switching occurrence has constructive effects. Consequently, recommendations have been made on the effective use of code-switching along with other pedagogical tools based on the research insights into code-switching when teaching and learning Orthographic Drawing. , Thesis (MEd) -- Faculty of Humanities, Study of Englishes of Africa, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Iita, Gabriel
- Date: 2023-10-13
- Subjects: Code switching (Linguistics) , Orthographic projection Study and teaching (Secondary) Namibia , English-medium instruction Namibia , Language and education , Social justice and education
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424041 , vital:72118
- Description: Studies in learner English proficiency in Namibia have shown that a considerable number of learners in primary and high schools have low proficiency. Naturally, this will be problematic for both learners and teachers who operate under a policy that dictates that from Grade 4 upwards, English is the medium of instruction in government schools. Literature has shown a general bias towards English as a medium of instruction from both the Namibian government and Namibian parents, despite the broader level of low English proficiency among learners. Research reviewed within this study has outlined the multiple benefits of code-switching for both learners and teachers. In fact, a recent study on the perceptions of code-switching in classrooms among Namibian learners indicated a positive attitude towards code-switching as a learning tool. Grade 8 Technical Drawing classes tend to be challenging due to the complexity and novelty of some of the concepts and terminologies used when teaching the subject. This makes it particularly difficult for learners whose first language is not English. Learners struggle to understand and make meaning of the concepts and objects used in Orthographic Drawing. Code-switching has been seen as a beneficial pedagogical tool. The study was therefore conducted to explore the Grade 8 teachers’ code-switching when teaching Orthographic Drawing in the Khomas educational region, Namibia. The study used the Matrix Language Frame Model by Myers-Scotton as the theoretical framework which focuses on two crucial language aspects of participating in code-switching and the matrix and embedded language, which guided this study. The qualitative approach employed a case study design which was used to gain first-hand experience in the Technical Drawing classrooms. Semi-structured interviews and an observation checklist were the research instruments that were used to generate data on the use of code-switching in Orthographic Drawing. Two schools, two Technical Drawing classes with 40 learners and two teachers in the Khomas region, Namibia were conveniently and purposively sampled. The data were analysed using coding, descriptive statistics and thematic data analysis. The primary and secondary results indicate that code-switching occurrence has constructive effects. Consequently, recommendations have been made on the effective use of code-switching along with other pedagogical tools based on the research insights into code-switching when teaching and learning Orthographic Drawing. , Thesis (MEd) -- Faculty of Humanities, Study of Englishes of Africa, 2023
- Full Text:
- Date Issued: 2023-10-13
Exploring how Grade 11 Chemistry teachers mediate learning of the topic redox reactions in their classrooms in Namibia
- Iindombo, Junilla Inamudhimbwa
- Authors: Iindombo, Junilla Inamudhimbwa
- Date: 2023-10-13
- Subjects: Chemistry Study and teaching (Secondary) Namibia , Pedagogical content knowledge , Oxidation Study and teaching (Secondary) Namibia , Oxidation-reduction reaction Study and teaching (Secondary) Activity programs Namibia , Practical work
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424030 , vital:72117
- Description: The Namibian Chemistry ordinary level syllabus requires learners to study the topic of redox reactions. This topic has proven to be one of the most difficult for Namibian learners as reflected by their poor responses to questions in the Grade 11 and 12 Namibian Senior Secondary Certificate ‘O’ examinations. Teaching abstract concepts such as redox reactions requires higher cognitive thinking skills and thus presents a challenge. Against this background, this study sought to explore how teachers mediate learning of redox reactions in their classrooms. The focus was on conceptual understanding through linking content to the context of the learners. The study was underpinned by an interpretivist paradigm, within which a qualitative case study approach was adopted. Two Grade 11 Chemistry teachers from the Ohangwena and Oshana regions in Namibia were the research participants. I used semi-structured interviews, lesson observations and stimulated recall interviews to collect data. I used Shulman’s Pedagogical Content Knowledge as a theoretical framework in this study and the data sets were analysed using the Topic-Specific Pedagogical Content Knowledge components. Qualitative data were analysed inductively-deductively. The study’s findings revealed that teachers used various mediation tools such as analogies and prior knowledge. The results further illuminated that teachers should develop strong subject content knowledge and pedagogical content knowledge to have the best strategies in place to mediate learning of this topic. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Iindombo, Junilla Inamudhimbwa
- Date: 2023-10-13
- Subjects: Chemistry Study and teaching (Secondary) Namibia , Pedagogical content knowledge , Oxidation Study and teaching (Secondary) Namibia , Oxidation-reduction reaction Study and teaching (Secondary) Activity programs Namibia , Practical work
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424030 , vital:72117
- Description: The Namibian Chemistry ordinary level syllabus requires learners to study the topic of redox reactions. This topic has proven to be one of the most difficult for Namibian learners as reflected by their poor responses to questions in the Grade 11 and 12 Namibian Senior Secondary Certificate ‘O’ examinations. Teaching abstract concepts such as redox reactions requires higher cognitive thinking skills and thus presents a challenge. Against this background, this study sought to explore how teachers mediate learning of redox reactions in their classrooms. The focus was on conceptual understanding through linking content to the context of the learners. The study was underpinned by an interpretivist paradigm, within which a qualitative case study approach was adopted. Two Grade 11 Chemistry teachers from the Ohangwena and Oshana regions in Namibia were the research participants. I used semi-structured interviews, lesson observations and stimulated recall interviews to collect data. I used Shulman’s Pedagogical Content Knowledge as a theoretical framework in this study and the data sets were analysed using the Topic-Specific Pedagogical Content Knowledge components. Qualitative data were analysed inductively-deductively. The study’s findings revealed that teachers used various mediation tools such as analogies and prior knowledge. The results further illuminated that teachers should develop strong subject content knowledge and pedagogical content knowledge to have the best strategies in place to mediate learning of this topic. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10-13
Gender and the COVID-19 pandemic: exploring female vendors’ coping strategies in Lichtenburg during the lockdown
- Authors: Marumo, Mmaki Lesego
- Date: 2023-10-13
- Subjects: COVID-19 Pandemic, 2020- South Africa , Street vendors South Africa Lichtenburg , Adjustment , Informal economy , COVID-19 pandemic lockdown , Self-employed women South Africa Lichtenburg
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425141 , vital:72214
- Description: The 2019 outbreak of the Coronavirus (COVID-19) in Wuhan, China, and its subsequent spread around the world caused uncertainty in the economy and other aspects of life. Most governments around the world took drastic measures to stop the spread of the virus and save lives. The most common of these measures were restrictions on people’s movement and trade. As a result, the world of work in South Africa changed dramatically, with over a million workers losing their jobs. That said, South Africa acutely felt the negative income effects of the COVID-19 pandemic. For those working in the informal economy, the five-week lockdown between March and May 2020 was a period of unprecedented insecurity and hunger, without work, income, or benefits. In light of the above, the study aimed to explore how female street vendors in Lichtenburg survived the impact of the COVID-19 national lockdown restrictions on trading activities between March 2020 and May 2020. The study sought to contribute to the understanding of the gendered impacts of the pandemic, particularly in relation to women in the informal economy, by examining the strategies and coping mechanisms adopted by them. Drawing on the sustainable livelihoods framework, this study examined the experiences of female street traders in Lichtenburg who were subjected to COVID-19 trade restrictions, assessed their coping strategies, and examined their support systems. The study was exploratory in nature, followed a qualitative approach, and adopted a case study design. Depending on the needs of the study, a purposive and convenience sampling techniques were chosen to address the research problem and questions. In order to explore women’s experiences on a specific topic, qualitative, semi-structured individual interviews were conducted with a sample of six female street vendors in Lichtenburg. The collected data were analysed using the thematic analysis technique. In this regard, the findings show that the perception upheld that the informal economy is an employment shock absorber during economic crises has been proven otherwise by the COVID-19 pandemic. The loss of profits led to a reduction in trading activities, which in turn increased the hardships of women street vendors. These vulnerability and hardships were made worse by the absence of government support structures since they were unable to navigate the procedures and had no one to turn to in times of need. As a result of the lack of formal channels of support and appropriate policy interventions, street vendors were particularly vulnerable to the financial consequences of the pandemic, resulting in an unpleasant reality of unsustainable livelihoods in the face of COVID-19. , Thesis (MA) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Marumo, Mmaki Lesego
- Date: 2023-10-13
- Subjects: COVID-19 Pandemic, 2020- South Africa , Street vendors South Africa Lichtenburg , Adjustment , Informal economy , COVID-19 pandemic lockdown , Self-employed women South Africa Lichtenburg
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425141 , vital:72214
- Description: The 2019 outbreak of the Coronavirus (COVID-19) in Wuhan, China, and its subsequent spread around the world caused uncertainty in the economy and other aspects of life. Most governments around the world took drastic measures to stop the spread of the virus and save lives. The most common of these measures were restrictions on people’s movement and trade. As a result, the world of work in South Africa changed dramatically, with over a million workers losing their jobs. That said, South Africa acutely felt the negative income effects of the COVID-19 pandemic. For those working in the informal economy, the five-week lockdown between March and May 2020 was a period of unprecedented insecurity and hunger, without work, income, or benefits. In light of the above, the study aimed to explore how female street vendors in Lichtenburg survived the impact of the COVID-19 national lockdown restrictions on trading activities between March 2020 and May 2020. The study sought to contribute to the understanding of the gendered impacts of the pandemic, particularly in relation to women in the informal economy, by examining the strategies and coping mechanisms adopted by them. Drawing on the sustainable livelihoods framework, this study examined the experiences of female street traders in Lichtenburg who were subjected to COVID-19 trade restrictions, assessed their coping strategies, and examined their support systems. The study was exploratory in nature, followed a qualitative approach, and adopted a case study design. Depending on the needs of the study, a purposive and convenience sampling techniques were chosen to address the research problem and questions. In order to explore women’s experiences on a specific topic, qualitative, semi-structured individual interviews were conducted with a sample of six female street vendors in Lichtenburg. The collected data were analysed using the thematic analysis technique. In this regard, the findings show that the perception upheld that the informal economy is an employment shock absorber during economic crises has been proven otherwise by the COVID-19 pandemic. The loss of profits led to a reduction in trading activities, which in turn increased the hardships of women street vendors. These vulnerability and hardships were made worse by the absence of government support structures since they were unable to navigate the procedures and had no one to turn to in times of need. As a result of the lack of formal channels of support and appropriate policy interventions, street vendors were particularly vulnerable to the financial consequences of the pandemic, resulting in an unpleasant reality of unsustainable livelihoods in the face of COVID-19. , Thesis (MA) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2023-10-13
Identification of novel Arf1 GTPase inhibitors for cancer target validation
- Authors: Mqwathi, Nomxolisi Vuyokasi
- Date: 2023-10-13
- Subjects: ARF1 , GTPase , Guanosine triphosphatase , Cancer Treatment
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424666 , vital:72173
- Description: The key regulators of both anterograde and retrograde vesicular traffic, adenosine diphosphate-ribosylation factors (Arfs), also coordinate various signalling pathways and regulate cellular processes required for cell survival and function. In addition to its role in mediating secretory trafficking in the Golgi apparatus, the involvement of Arf1 in signalling pathways that contribute to the formation and progression of cancer has become apparent, and the overexpression and deregulation of Arf1 activity has been associated with cancer cell invasion, proliferation and metastasis. As with other small GTPases, Arf1 must cycle back and forth between an inactive (GDP-bound) and active (GTP-bound) conformation to carry out its function. However, the cycle of Arf1 inactivation and activation is controlled by Arf GTPase activating proteins (Arf-GAPs) that stimulate Arf1 to hydrolyse the bound GTP to GDP and Arf guanine nucleotide exchange factors (Arf-GEFs) that facilitate GDP for GTP exchange on Arf1, respectively. The identification of Arf1 inhibitors that indirectly disrupt Arf1 function by blocking its interaction with Arf-GAPs or Arf-GEFs has generated interest in their use as possible anti-cancer agents. The suppression of Arf1 activation (by targeting Arf-GEFs) has been investigated as a potential cancer therapeutic target and resulted in inhibitor compounds that have micromolar-range activity against cancer cells and targets and promising results in mouse models, but experience problems with bioavailability when used in vivo. This motivates the search for novel Arf1 inhibitors for validation purposes to question whether Arf1 is a viable target for cancer therapy. The purpose of the study was to employ a recently developed colourimetric screening assay to identify inhibitors of Arf1 activation (Arf-GEF inhibitors) and deactivation (Arf-GAP inhibitors), with a focus on evaluating the potential of Arf1 deactivation as an entirely novel anti-cancer target. The proteins required for the assay (Arf1, Arf-GEF and -GAP domains and a reporter protein, GST-GGA3) were expressed in E. coli. and purified using affinity chromatography. The assay could detect the activation of Arf1 by the catalytic Sec7 domain of the three Arf-GEFs chosen for this study, but reproducibility was compromised by the occasional spontaneous activation of Arf1 in the absence of the Arf-GEFs. By contrast, the assay could reproducibly detect Arf1 deactivation by an Arf-GAP domain (Arf-GAP1GAP) and was subsequently used to screen a library of α-helix mimetics. Thirteen hit compounds with IC50 values ranging from 0.53 to 20.95 μM were found to inhibit Arf-GAP1GAP-mediated stimulation of GTP hydrolysis by Arf1-GTP in this assay format, however, they did not effectively suppress the proliferation of three tested cell lines (HeLa, MCF-7 and MCF-12A). Interestingly, the results obtained from fluorescence microscopy studies suggested that the compounds disrupt Golgi structure and Arf1 localisation, presumably by keeping Arf1 in its active conformation by blocking Arf-GAP1 function. This suggests that the compounds affect Arf1 function in cells, and may be used to explore the feasibility of targeting Arf1 deactivation for anti-cancer purposes in a wider range of cell lines and experiments. It has been reported that Arf-GAP1 inhibition is associated with the suppression of cell migration, and the potential of the compounds as metastasis inhibitors may also be explored. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Mqwathi, Nomxolisi Vuyokasi
- Date: 2023-10-13
- Subjects: ARF1 , GTPase , Guanosine triphosphatase , Cancer Treatment
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424666 , vital:72173
- Description: The key regulators of both anterograde and retrograde vesicular traffic, adenosine diphosphate-ribosylation factors (Arfs), also coordinate various signalling pathways and regulate cellular processes required for cell survival and function. In addition to its role in mediating secretory trafficking in the Golgi apparatus, the involvement of Arf1 in signalling pathways that contribute to the formation and progression of cancer has become apparent, and the overexpression and deregulation of Arf1 activity has been associated with cancer cell invasion, proliferation and metastasis. As with other small GTPases, Arf1 must cycle back and forth between an inactive (GDP-bound) and active (GTP-bound) conformation to carry out its function. However, the cycle of Arf1 inactivation and activation is controlled by Arf GTPase activating proteins (Arf-GAPs) that stimulate Arf1 to hydrolyse the bound GTP to GDP and Arf guanine nucleotide exchange factors (Arf-GEFs) that facilitate GDP for GTP exchange on Arf1, respectively. The identification of Arf1 inhibitors that indirectly disrupt Arf1 function by blocking its interaction with Arf-GAPs or Arf-GEFs has generated interest in their use as possible anti-cancer agents. The suppression of Arf1 activation (by targeting Arf-GEFs) has been investigated as a potential cancer therapeutic target and resulted in inhibitor compounds that have micromolar-range activity against cancer cells and targets and promising results in mouse models, but experience problems with bioavailability when used in vivo. This motivates the search for novel Arf1 inhibitors for validation purposes to question whether Arf1 is a viable target for cancer therapy. The purpose of the study was to employ a recently developed colourimetric screening assay to identify inhibitors of Arf1 activation (Arf-GEF inhibitors) and deactivation (Arf-GAP inhibitors), with a focus on evaluating the potential of Arf1 deactivation as an entirely novel anti-cancer target. The proteins required for the assay (Arf1, Arf-GEF and -GAP domains and a reporter protein, GST-GGA3) were expressed in E. coli. and purified using affinity chromatography. The assay could detect the activation of Arf1 by the catalytic Sec7 domain of the three Arf-GEFs chosen for this study, but reproducibility was compromised by the occasional spontaneous activation of Arf1 in the absence of the Arf-GEFs. By contrast, the assay could reproducibly detect Arf1 deactivation by an Arf-GAP domain (Arf-GAP1GAP) and was subsequently used to screen a library of α-helix mimetics. Thirteen hit compounds with IC50 values ranging from 0.53 to 20.95 μM were found to inhibit Arf-GAP1GAP-mediated stimulation of GTP hydrolysis by Arf1-GTP in this assay format, however, they did not effectively suppress the proliferation of three tested cell lines (HeLa, MCF-7 and MCF-12A). Interestingly, the results obtained from fluorescence microscopy studies suggested that the compounds disrupt Golgi structure and Arf1 localisation, presumably by keeping Arf1 in its active conformation by blocking Arf-GAP1 function. This suggests that the compounds affect Arf1 function in cells, and may be used to explore the feasibility of targeting Arf1 deactivation for anti-cancer purposes in a wider range of cell lines and experiments. It has been reported that Arf-GAP1 inhibition is associated with the suppression of cell migration, and the potential of the compounds as metastasis inhibitors may also be explored. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
In-silico investigation of the effects of genetic mutations on the structural dynamics of thiopurine s-methyltransferase and their implications on the metabolism of 6-mercaptopurine
- Authors: Mwaniki, Rehema Mukami
- Date: 2023-10-13
- Subjects: Mutation , Thiopurine S-methyltransferase , Mercaptopurine , Molecular dynamics , Protein structure , Structural dynamics
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/432553 , vital:72880
- Description: Thiopurine S-methyltransferase (TPMT) is a cytosolic enzyme that catalyzes the S-methylation of aromatic and heterocyclic sulfhydryl compounds such as 6-mercaptopurine (6MP), 6-thioguanine (6TG) and azathioprine (AZA) which is first converted to 6MP through reduction by glutathione S- transferases (GST). The compounds, generally referred to as thiopurines, are immunosuppressants used to treat childhood acute lymphoblastic leukemia (ALL), autoimmune disorders and transplant rejection. Thiopurines are prodrugs which require metabolic activation to give thioguanine nucleotides that exert their cytotoxic effects by incorporation into DNA or inhibiting purine synthesis. The methylation reaction by TPMT utilizing S-adenosylmethionine (SAM) as the methyl donor prevents their conversion to these toxic compounds. The catalytic activity of TPMT in metabolising these compounds has been associated with occurrence of genetic variations. The variations that result to missense mutations cause amino-acid changes and in turn alter the polypeptide sequence of the protein. This could alter functionality and structural dynamics of the enzyme. This study sought to understand the underlying mechanism by which 7 specially selected mutations impede metabolic activity of the enzyme on 6-MP using in silico techniques. VAPOR and PredictSNP were used to predict the effects of single nucleotide polymorphisms (SNPs) on the stability and function of the enzyme. Of the 7 mutations, only H227Q was predicted to be functionally benign while the rest (L49S, L69V, A80P, R163H, R163C and R163P) were predicted to be deleterious or associated with disease. All the SNPs were predicted to destabilize the enzyme. Molecular dynamics (MD) simulations were preformed to mimic the behaviour of the apo, holo and drug-bound WT and mutant enzymes in vivo. This was followed by post-MD analysis to identify changes in the local and global motions of the protein in the presence of mutations and changes in intra-protein communication networks through contact map and centrality metrics calculations. RMSD and Rg analyses were performed to assess changes in global motions and compactness of the enzyme in the apo, holo and drug-bound states and in the presence of mutations. These revealed that binding of the ligand had a stabilizing effect on the WT enzyme evident from more steady trends from the analyses across trajectories in the holo and drug-bound enzymes compared to the apoenzyme. The occurrence of mutations had an effect on the global motions and compactness of the enzyme across the trajectories. Most mutations resulted in destabilized systems and less compact structures shown by unsteady RMSD and Rg across trajectories respectively. The drugbound systems appeared to be more stable in most of the systems meaning that the binding of 6MP stabilized the enzyme regardless of the presence of a mutation. RMSF analysis recorded local changes in residue flexibility due to the presence of mutations in all the systems. All the drug-bound mutant systems lost flexibility on the αAhelix which caps the active site. This could have an effect on drug binding and result to defective drug metabolism. The A80P mutation resulted to a more rigid structure from both global and local motions compared to the WT enzyme which could be associated with its nearly loss of function in vivo and in vitro. Dynamic cross correlation calculations were performed to assess how the atoms moved together. Correlated, anti-correlated and areas of no correlations were recorded in all the systems and in similar places when compared to each other. This meant that occurrence of mutations had no effect on how the atoms moved together. Contact map analysis showed that occurrence of mutations caused changes in interactions around the positions where the mutations occurred, which could have an effect on protein structural dynamics. The A80P substitution which occurred on the surface away from the binding site was identified as an allosteric mutation that resulted to changes in the catalytic site. Contact maps for the drug-cofactor complex in the mutant systems in comparison with the WT protein revealed changes that could suggest reorientation of the drug at the catalytic site. This could be an implication to altered drug metabolism. Eigenvector centrality (EC) and betweenness centrality (BC) for the most equilibrated portions of the trajectories were calculated for all the studied systems to identify residues connected to the most important residues and those that were spanned the most in shortest paths connecting other residues. Areas that scored highest in these metrics where mostly found in regions surrounding the catalytic site. Top 5% centrality hubs calculations showed loss of major hubs due to mutations with gaining of new ones. This means that mutations affected communication networks within the protein. The gained hubs were in areas close-by the lost ones which could have been an attempt of the protein to accommodate the mutations. Persistent top 5% BC hubs were identified at positions 90 and 151 while one persistent top 5% EC hub was identified at position 70. This positions play important roles in shaping the catalytic site and are in direct contact with the ligands. It was concluded that in silico techniques and analysis applied in this study revealed possible mechanisms in which genetic variations affected the structural dynamics of TMPT enzyme an affecte 6MP metabolism. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Mwaniki, Rehema Mukami
- Date: 2023-10-13
- Subjects: Mutation , Thiopurine S-methyltransferase , Mercaptopurine , Molecular dynamics , Protein structure , Structural dynamics
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/432553 , vital:72880
- Description: Thiopurine S-methyltransferase (TPMT) is a cytosolic enzyme that catalyzes the S-methylation of aromatic and heterocyclic sulfhydryl compounds such as 6-mercaptopurine (6MP), 6-thioguanine (6TG) and azathioprine (AZA) which is first converted to 6MP through reduction by glutathione S- transferases (GST). The compounds, generally referred to as thiopurines, are immunosuppressants used to treat childhood acute lymphoblastic leukemia (ALL), autoimmune disorders and transplant rejection. Thiopurines are prodrugs which require metabolic activation to give thioguanine nucleotides that exert their cytotoxic effects by incorporation into DNA or inhibiting purine synthesis. The methylation reaction by TPMT utilizing S-adenosylmethionine (SAM) as the methyl donor prevents their conversion to these toxic compounds. The catalytic activity of TPMT in metabolising these compounds has been associated with occurrence of genetic variations. The variations that result to missense mutations cause amino-acid changes and in turn alter the polypeptide sequence of the protein. This could alter functionality and structural dynamics of the enzyme. This study sought to understand the underlying mechanism by which 7 specially selected mutations impede metabolic activity of the enzyme on 6-MP using in silico techniques. VAPOR and PredictSNP were used to predict the effects of single nucleotide polymorphisms (SNPs) on the stability and function of the enzyme. Of the 7 mutations, only H227Q was predicted to be functionally benign while the rest (L49S, L69V, A80P, R163H, R163C and R163P) were predicted to be deleterious or associated with disease. All the SNPs were predicted to destabilize the enzyme. Molecular dynamics (MD) simulations were preformed to mimic the behaviour of the apo, holo and drug-bound WT and mutant enzymes in vivo. This was followed by post-MD analysis to identify changes in the local and global motions of the protein in the presence of mutations and changes in intra-protein communication networks through contact map and centrality metrics calculations. RMSD and Rg analyses were performed to assess changes in global motions and compactness of the enzyme in the apo, holo and drug-bound states and in the presence of mutations. These revealed that binding of the ligand had a stabilizing effect on the WT enzyme evident from more steady trends from the analyses across trajectories in the holo and drug-bound enzymes compared to the apoenzyme. The occurrence of mutations had an effect on the global motions and compactness of the enzyme across the trajectories. Most mutations resulted in destabilized systems and less compact structures shown by unsteady RMSD and Rg across trajectories respectively. The drugbound systems appeared to be more stable in most of the systems meaning that the binding of 6MP stabilized the enzyme regardless of the presence of a mutation. RMSF analysis recorded local changes in residue flexibility due to the presence of mutations in all the systems. All the drug-bound mutant systems lost flexibility on the αAhelix which caps the active site. This could have an effect on drug binding and result to defective drug metabolism. The A80P mutation resulted to a more rigid structure from both global and local motions compared to the WT enzyme which could be associated with its nearly loss of function in vivo and in vitro. Dynamic cross correlation calculations were performed to assess how the atoms moved together. Correlated, anti-correlated and areas of no correlations were recorded in all the systems and in similar places when compared to each other. This meant that occurrence of mutations had no effect on how the atoms moved together. Contact map analysis showed that occurrence of mutations caused changes in interactions around the positions where the mutations occurred, which could have an effect on protein structural dynamics. The A80P substitution which occurred on the surface away from the binding site was identified as an allosteric mutation that resulted to changes in the catalytic site. Contact maps for the drug-cofactor complex in the mutant systems in comparison with the WT protein revealed changes that could suggest reorientation of the drug at the catalytic site. This could be an implication to altered drug metabolism. Eigenvector centrality (EC) and betweenness centrality (BC) for the most equilibrated portions of the trajectories were calculated for all the studied systems to identify residues connected to the most important residues and those that were spanned the most in shortest paths connecting other residues. Areas that scored highest in these metrics where mostly found in regions surrounding the catalytic site. Top 5% centrality hubs calculations showed loss of major hubs due to mutations with gaining of new ones. This means that mutations affected communication networks within the protein. The gained hubs were in areas close-by the lost ones which could have been an attempt of the protein to accommodate the mutations. Persistent top 5% BC hubs were identified at positions 90 and 151 while one persistent top 5% EC hub was identified at position 70. This positions play important roles in shaping the catalytic site and are in direct contact with the ligands. It was concluded that in silico techniques and analysis applied in this study revealed possible mechanisms in which genetic variations affected the structural dynamics of TMPT enzyme an affecte 6MP metabolism. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13