Understanding critical concepts in engaged research to promote health resilience: the case of a systems analysis and epistemically just rural health development project in South Africa
- Authors: Duxbury, Theodore Orlando
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431509 , vital:72781
- Description: Access restricted. Expected release date 2025. , Thesis (PhD) -- Faculty of Pharmacy, Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Duxbury, Theodore Orlando
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431509 , vital:72781
- Description: Access restricted. Expected release date 2025. , Thesis (PhD) -- Faculty of Pharmacy, Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-13
Uviwe Umthandazo
- Authors: Madinda, Viwe
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425344 , vital:72231
- Description: The discourse of identity and community are topics of interest to me. As a citizen living in post-apartheid South Africa, I am captivated by the re-emerging wisdom and knowledge of Nguni cultural philosophies and practices. My practice-based research is interested in a creative interpretation of these ancient philosophies and practices in the context of postcolonial life. The project in many ways re-members through observation of socio-political issues such as inequality, violence, and vandalism as reflections of internal challenges of the individual self in current reality. In essence, my discussion in this paper highlights the need for healing grief and loss for the well-being – physical, emotional, mental, and spiritual – of society. Self-definition is the core of any community and we see this in the philosophy of the African proverb umntu ngumntu ngabantu, ‘I am because you are’. ‘I am’ is a set of beliefs that construct the individual self; our life’s course then becomes a constant molding of the body and the world around us. The wisdom of ubuntu was, and is, a catalyst for many African cultures, as this law recognizes each individual as important and equal in the community. As a descendant of various indigenous clans originating in Africa the well-being and balance of my being is determined by how much I know about who I am. Consequently, being a part of the generation that is experiencing the transitioning phases from apartheid I question the ways we are dealing with the residue of coloniality concerning all aspects of self; the physical, emotional, and mental bodies of self. My creative work is a reflection of the exercises I implemented to cultivate selfhood as a way to participate in and control my reality as a marginalized member of society. The different chapters touch on many intersecting theories about tools for healing/soothing the self. The creative process experimented with the various concepts embedded in the expression ‘I am because you are’. In the process of this research, I learned that knowing yourself is one of the principles of ubuntu, which teaches me that I cannot be or give what I do not have. The themes I explore through the above expression are self-love, self-acceptance, and self-respect using a creative lens. This practice-based research proposes a concept; the act of love as a decolonial gesture. My exhibition Vuleka Mhlaba Ndinegene1 utilizes visual language to convey the need for more conversations on healing using natural elements, as a way to make a connection between self, the natural environment, and community. In the first and second chapters, the paper focuses on practices employed by artists such as Lhola Amira, Guadalupe Maravilla, Buhlebezwe Siwani, Tony Gum, Lina Iris Viktor, and Aida Muleneh, to relate the various approaches to re-member the severed connection between self, nature, and community. This study looks at theories on; holding space, sound healing, earthing, shadow work, astrology, and human consciousness. , Thesis (MFA) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Madinda, Viwe
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425344 , vital:72231
- Description: The discourse of identity and community are topics of interest to me. As a citizen living in post-apartheid South Africa, I am captivated by the re-emerging wisdom and knowledge of Nguni cultural philosophies and practices. My practice-based research is interested in a creative interpretation of these ancient philosophies and practices in the context of postcolonial life. The project in many ways re-members through observation of socio-political issues such as inequality, violence, and vandalism as reflections of internal challenges of the individual self in current reality. In essence, my discussion in this paper highlights the need for healing grief and loss for the well-being – physical, emotional, mental, and spiritual – of society. Self-definition is the core of any community and we see this in the philosophy of the African proverb umntu ngumntu ngabantu, ‘I am because you are’. ‘I am’ is a set of beliefs that construct the individual self; our life’s course then becomes a constant molding of the body and the world around us. The wisdom of ubuntu was, and is, a catalyst for many African cultures, as this law recognizes each individual as important and equal in the community. As a descendant of various indigenous clans originating in Africa the well-being and balance of my being is determined by how much I know about who I am. Consequently, being a part of the generation that is experiencing the transitioning phases from apartheid I question the ways we are dealing with the residue of coloniality concerning all aspects of self; the physical, emotional, and mental bodies of self. My creative work is a reflection of the exercises I implemented to cultivate selfhood as a way to participate in and control my reality as a marginalized member of society. The different chapters touch on many intersecting theories about tools for healing/soothing the self. The creative process experimented with the various concepts embedded in the expression ‘I am because you are’. In the process of this research, I learned that knowing yourself is one of the principles of ubuntu, which teaches me that I cannot be or give what I do not have. The themes I explore through the above expression are self-love, self-acceptance, and self-respect using a creative lens. This practice-based research proposes a concept; the act of love as a decolonial gesture. My exhibition Vuleka Mhlaba Ndinegene1 utilizes visual language to convey the need for more conversations on healing using natural elements, as a way to make a connection between self, the natural environment, and community. In the first and second chapters, the paper focuses on practices employed by artists such as Lhola Amira, Guadalupe Maravilla, Buhlebezwe Siwani, Tony Gum, Lina Iris Viktor, and Aida Muleneh, to relate the various approaches to re-member the severed connection between self, nature, and community. This study looks at theories on; holding space, sound healing, earthing, shadow work, astrology, and human consciousness. , Thesis (MFA) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
- Date Issued: 2023-10-13
Visual representations of linear algebraic expressions: a case study in a Grade 9 after-school mathematics club
- Authors: Herbert, Sindisiwe
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424019 , vital:72116
- Description: Visualisation is commonly used as a tool in introducing algebra through visual or kinaesthetic sequences designed to prompt learners' development of a general rule for moving from a term's position to its output value. Fluency in both the concepts and the conventions of elementary algebra are essential to learners, as algebra forms the language in which many advanced mathematical ideas are encoded. Moreover, algebraic fluency is often associated with an ability to think abstractly about arithmetic processes. In many classrooms, however, research has shown that learners often focus on fluency in algebraic conventions rather than concepts, learning how to manipulate expressions without understanding the algorithms they are taught to follow. This trend can be linked to several causes, including teacher-centred mathematics classrooms in which learners are – whether implicitly or explicitly – encouraged to copy formulae and methods in order to ‘get it right in a test’ without necessarily grasping the underlying logical relationships. This case study, therefore, aimed to determine whether there was value in using visual, kinaesthetic models to broaden and deepen learners' use of algebra. To that end, in the context of an extra-curricular mathematics club that aimed to decentre the teachers and demand innovative ideas of the participants, six pairs of Grade 9 learners were tasked with creating visual representations of a linear algebraic expression using coloured building cubes. The responses to this task over the course of five assignments were many and varied and almost universally displayed a sustained internal logic that the learners were able to explain and develop. Most pairs began with a visual list of terms arranged in sets of towers, pyramids or, in one case, a spiral. At the end of the study, all but one of the pairs had settled on a Visual Expression, in which various colours were used to represent elements of the algebra such as the values of the coefficient, the variable and the constant term. The participants' representations grew in complexity over the course of the study and the conformity of the final responses showed that the club was a collaborative space in which learners shared ideas. However, the structure of the Visual Expressions and their own confessions of nerves about ‘getting it wrong’ in the interviews suggest that the participants were stuck in a mindset that led them to seek out and idealise the representation closest to the original algebra, even though that representation revealed little about the structural relationship underlying the expression. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Herbert, Sindisiwe
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424019 , vital:72116
- Description: Visualisation is commonly used as a tool in introducing algebra through visual or kinaesthetic sequences designed to prompt learners' development of a general rule for moving from a term's position to its output value. Fluency in both the concepts and the conventions of elementary algebra are essential to learners, as algebra forms the language in which many advanced mathematical ideas are encoded. Moreover, algebraic fluency is often associated with an ability to think abstractly about arithmetic processes. In many classrooms, however, research has shown that learners often focus on fluency in algebraic conventions rather than concepts, learning how to manipulate expressions without understanding the algorithms they are taught to follow. This trend can be linked to several causes, including teacher-centred mathematics classrooms in which learners are – whether implicitly or explicitly – encouraged to copy formulae and methods in order to ‘get it right in a test’ without necessarily grasping the underlying logical relationships. This case study, therefore, aimed to determine whether there was value in using visual, kinaesthetic models to broaden and deepen learners' use of algebra. To that end, in the context of an extra-curricular mathematics club that aimed to decentre the teachers and demand innovative ideas of the participants, six pairs of Grade 9 learners were tasked with creating visual representations of a linear algebraic expression using coloured building cubes. The responses to this task over the course of five assignments were many and varied and almost universally displayed a sustained internal logic that the learners were able to explain and develop. Most pairs began with a visual list of terms arranged in sets of towers, pyramids or, in one case, a spiral. At the end of the study, all but one of the pairs had settled on a Visual Expression, in which various colours were used to represent elements of the algebra such as the values of the coefficient, the variable and the constant term. The participants' representations grew in complexity over the course of the study and the conformity of the final responses showed that the club was a collaborative space in which learners shared ideas. However, the structure of the Visual Expressions and their own confessions of nerves about ‘getting it wrong’ in the interviews suggest that the participants were stuck in a mindset that led them to seek out and idealise the representation closest to the original algebra, even though that representation revealed little about the structural relationship underlying the expression. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10-13
Vulamasango Singene: sociological analysis of a rural social movement
- Authors: Kirchmann, Gail Lynne
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425132 , vital:72213
- Description: This dissertation tests the claim made by a large membership-based organisation that it is a social movement. The organisation, Vulamasango Singene (VS) operates across the rural areas of large parts of the Eastern Cape Province. It has, for twenty years, advocated for the re-opening of land restitution claims for a specific category of forced removal known as “betterment”. This study provides an analysis of an organisation that has yet to achieve its objective in spite of sufficient financial resources, logistical and strategic support, numeric strength and the legal clarity of its demand. The research is situated within the framework of social movement theory. The study examined the origins, institutional infrastructure, demographic make-up, activities and culture of VS. These were analysed against four components that are identified in the literature as key characteristics of a social movement. These are: (i) informal networks (as opposed to structured and managed engagements); (ii) a plurality of actors (as opposed to a homogenous grouping); (iii) mobilising around issues of conflict; and (iv) sharing common beliefs and demonstrating solidarity. Data were gathered through an archival study and field research. Semi-structured interviews were carried out with a sample of VS’s leadership, and staff of the non-governmental organisation in which VS originated, as well as expert informants in the land reform arena. The findings with respect to each of the criteria were: (i) VS’s structure was rigid and internal communication was largely formal. (ii) There was almost no demographic or political diversity within VS. (iii) VS had, in the past, mobilised around issues of conflict, but there had been no mobilisation for ten years. (iv) While there was some evidence of sharing common beliefs and demonstrating solidarity, this was limited. The conclusion reached was that VS is not a social movement. This does not imply that VS is not an important democratic or representative organisation. It does, however, provide a theoretical position from which VS, and other organisations, can direct further action. The study touched on the relationship between northern donors, local professional NGOs and grassroots organisations in South Africa. Interactions among these institutions impact on the way that organisations and social movements develop. Comparisons with other similar organisations were made and similarities and differences were highlighted. It was suggested that, because of the importance of the issue, further research in this regard is necessary. , Thesis (MA) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Kirchmann, Gail Lynne
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425132 , vital:72213
- Description: This dissertation tests the claim made by a large membership-based organisation that it is a social movement. The organisation, Vulamasango Singene (VS) operates across the rural areas of large parts of the Eastern Cape Province. It has, for twenty years, advocated for the re-opening of land restitution claims for a specific category of forced removal known as “betterment”. This study provides an analysis of an organisation that has yet to achieve its objective in spite of sufficient financial resources, logistical and strategic support, numeric strength and the legal clarity of its demand. The research is situated within the framework of social movement theory. The study examined the origins, institutional infrastructure, demographic make-up, activities and culture of VS. These were analysed against four components that are identified in the literature as key characteristics of a social movement. These are: (i) informal networks (as opposed to structured and managed engagements); (ii) a plurality of actors (as opposed to a homogenous grouping); (iii) mobilising around issues of conflict; and (iv) sharing common beliefs and demonstrating solidarity. Data were gathered through an archival study and field research. Semi-structured interviews were carried out with a sample of VS’s leadership, and staff of the non-governmental organisation in which VS originated, as well as expert informants in the land reform arena. The findings with respect to each of the criteria were: (i) VS’s structure was rigid and internal communication was largely formal. (ii) There was almost no demographic or political diversity within VS. (iii) VS had, in the past, mobilised around issues of conflict, but there had been no mobilisation for ten years. (iv) While there was some evidence of sharing common beliefs and demonstrating solidarity, this was limited. The conclusion reached was that VS is not a social movement. This does not imply that VS is not an important democratic or representative organisation. It does, however, provide a theoretical position from which VS, and other organisations, can direct further action. The study touched on the relationship between northern donors, local professional NGOs and grassroots organisations in South Africa. Interactions among these institutions impact on the way that organisations and social movements develop. Comparisons with other similar organisations were made and similarities and differences were highlighted. It was suggested that, because of the importance of the issue, further research in this regard is necessary. , Thesis (MA) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2023-10-13
Wildlife-vehicle collisions mitigation measures using road ecological data and deep learning
- Authors: Nandutu, Irene
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431907 , vital:72814
- Description: Access restricted. Expected release in 2025. , Thesis (PhD) -- Faculty of Science, Mathematics, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Nandutu, Irene
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431907 , vital:72814
- Description: Access restricted. Expected release in 2025. , Thesis (PhD) -- Faculty of Science, Mathematics, 2023
- Full Text:
- Date Issued: 2023-10-13
Year-end oversight in Local Government: a case study of water and sanitation service delivery at Amathole District Municipality
- Authors: Seoke, Duncan
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425206 , vital:72219
- Description: Poor service delivery is a challenge that has continued to plague the constitutional democracy of South Africa. Legislation has, in response, been passed to ensure efficient service delivery. Despite this legislation, municipal service delivery has been alarmingly poor, and reports on municipal performance and newspaper articles have corroborated this. On the causes of poor service delivery, the existing literature appears to have focused on financial mismanagement, corruption, and the incapacity of officials. Absent from existing literature are discussions on how municipal service delivery is affected by the lack of interrelatedness between municipal public resource management processes (such as revenue collection, expenditure management and oversight). This dissertation addresses this gap by examining the municipal public resource management processes from an oversight perspective. The study sought to analyse the effectiveness of year-end oversight at Amathole District Municipality (ADM) over water and sanitation services. This research aimed to study the year-end oversight over service delivery with reference to the Municipal Public Resource Management (MPRM) model. According to the model, effective service delivery includes inter alia effective oversight, as oversight forms part of the entire system of the municipal resource management cycle. Thus, for the MPRM model, oversight should be exercised on all these processes. The research was a desktop analysis that used both a qualitative and quantitative research methodology. The primary document analysed was the ADM Oversight Report (OR). This report is produced by the Municipal Public Accounts Committee (MPAC) and reflects the year-end oversight conducted by the MPAC on the municipality's activities. In the analysis of the OR, it was concluded that the ADM MPAC had failed to conduct effective year-end oversight of W&S services. The efficacy of the ADM MPAC's year-end oversight was measured against guidelines for effective year-end oversight from the National Treasury and the MPRM model. The findings suggested that there were inefficiencies in the manner that the ADM MPAC exercised its year-end oversight. , Thesis (MA) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Seoke, Duncan
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425206 , vital:72219
- Description: Poor service delivery is a challenge that has continued to plague the constitutional democracy of South Africa. Legislation has, in response, been passed to ensure efficient service delivery. Despite this legislation, municipal service delivery has been alarmingly poor, and reports on municipal performance and newspaper articles have corroborated this. On the causes of poor service delivery, the existing literature appears to have focused on financial mismanagement, corruption, and the incapacity of officials. Absent from existing literature are discussions on how municipal service delivery is affected by the lack of interrelatedness between municipal public resource management processes (such as revenue collection, expenditure management and oversight). This dissertation addresses this gap by examining the municipal public resource management processes from an oversight perspective. The study sought to analyse the effectiveness of year-end oversight at Amathole District Municipality (ADM) over water and sanitation services. This research aimed to study the year-end oversight over service delivery with reference to the Municipal Public Resource Management (MPRM) model. According to the model, effective service delivery includes inter alia effective oversight, as oversight forms part of the entire system of the municipal resource management cycle. Thus, for the MPRM model, oversight should be exercised on all these processes. The research was a desktop analysis that used both a qualitative and quantitative research methodology. The primary document analysed was the ADM Oversight Report (OR). This report is produced by the Municipal Public Accounts Committee (MPAC) and reflects the year-end oversight conducted by the MPAC on the municipality's activities. In the analysis of the OR, it was concluded that the ADM MPAC had failed to conduct effective year-end oversight of W&S services. The efficacy of the ADM MPAC's year-end oversight was measured against guidelines for effective year-end oversight from the National Treasury and the MPRM model. The findings suggested that there were inefficiencies in the manner that the ADM MPAC exercised its year-end oversight. , Thesis (MA) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2023-10-13
“Rwanda cannot be exorcised”: representations of the trauma of the Rwandan Genocide in selected films and novels
- Authors: Jennings, Kathleen
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425067 , vital:72206
- Description: Although the Rwandan genocide (itsembabwoko in Kinyarwanda) has often been compared with the Holocaust, in terms of literary and cinematic narratives it has been largely underrepresented, with the notable exception of the release of the films Hotel Rwanda (2004) and Sometimes in April (2005), as well as novels such as Gil Courtemanche’s A Sunday at the Pool in Kigali (2003). However, although there is now a larger oeuvre of works on the subject, they are often not widely known or disseminated beyond their countries of origin. Of even greater concern is the fact that most cinematic narratives on itsembabwoko rely on Western narrative structures in their approach to storytelling. As a result, trauma in these narratives largely tends to focus on the experiences of Western protagonists or on Rwandan protagonists from a Western point of view. This tendency can be tied to the use of Western trauma theory in exploring the effects of the genocide on its witnesses and survivors, at the expense of arguably more relevant postcolonial trauma theory. This presents a problem in theorising the trauma of itsembabwoko, which occurred in a highly specific historical context involving the processes of colonization and decolonization, and in which the difficulties in unifying a population which had been split along socio-economic lines since pre-colonial times remained unresolved. Despite its shortcomings in the postcolonial African context, it would be a mistake to dismiss Yale trauma theory entirely, however, since theorists such as Cathy Caruth still provide valuable insights into the effects of trauma on both the individual and the collective. As a result, I have sought to find commonalities between the two schools of thought, so as to create a more nuanced view of itsembabwoko, its repercussions and the violence preceding it. In writing this thesis, I have selected mostly Rwandan authors, often survivors of the genocide, whose works provide an alternative view of Rwanda’s violent history to that presented in the works mentioned above. Given that the majority of the texts I focus on have been released more recently – mostly the mid-2010s – and are less well-known than their Western counterparts, they provide the opportunity to compare first-hand accounts with those that can only partially recreate the terror of anti-Tutsi violence in Rwanda. My analysis hopefully provides a new perspective on the dominant narratives which have shaped the way in which non-Rwandan (predominantly Western) audiences understand the genocide. The overall aim of this thesis, then, is to demonstrate the importance of placing the genocide and its resultant trauma in a broader historical context, with a view to establishing that it is shortsighted to ignore the impact of pre- and post-genocide trauma on the Rwandan people when discussing itsembabwoko. Though this has been achieved in socio-historical studies, such as Mahmood Mamdani’s When Victims Become Killers: Colonialism, Nativism, and the Genocide in Rwanda, very little has been produced on literary and cinematic representations of the genocide. , Thesis (MA) -- Faculty of Humanities, Literary Studies in English 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Jennings, Kathleen
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425067 , vital:72206
- Description: Although the Rwandan genocide (itsembabwoko in Kinyarwanda) has often been compared with the Holocaust, in terms of literary and cinematic narratives it has been largely underrepresented, with the notable exception of the release of the films Hotel Rwanda (2004) and Sometimes in April (2005), as well as novels such as Gil Courtemanche’s A Sunday at the Pool in Kigali (2003). However, although there is now a larger oeuvre of works on the subject, they are often not widely known or disseminated beyond their countries of origin. Of even greater concern is the fact that most cinematic narratives on itsembabwoko rely on Western narrative structures in their approach to storytelling. As a result, trauma in these narratives largely tends to focus on the experiences of Western protagonists or on Rwandan protagonists from a Western point of view. This tendency can be tied to the use of Western trauma theory in exploring the effects of the genocide on its witnesses and survivors, at the expense of arguably more relevant postcolonial trauma theory. This presents a problem in theorising the trauma of itsembabwoko, which occurred in a highly specific historical context involving the processes of colonization and decolonization, and in which the difficulties in unifying a population which had been split along socio-economic lines since pre-colonial times remained unresolved. Despite its shortcomings in the postcolonial African context, it would be a mistake to dismiss Yale trauma theory entirely, however, since theorists such as Cathy Caruth still provide valuable insights into the effects of trauma on both the individual and the collective. As a result, I have sought to find commonalities between the two schools of thought, so as to create a more nuanced view of itsembabwoko, its repercussions and the violence preceding it. In writing this thesis, I have selected mostly Rwandan authors, often survivors of the genocide, whose works provide an alternative view of Rwanda’s violent history to that presented in the works mentioned above. Given that the majority of the texts I focus on have been released more recently – mostly the mid-2010s – and are less well-known than their Western counterparts, they provide the opportunity to compare first-hand accounts with those that can only partially recreate the terror of anti-Tutsi violence in Rwanda. My analysis hopefully provides a new perspective on the dominant narratives which have shaped the way in which non-Rwandan (predominantly Western) audiences understand the genocide. The overall aim of this thesis, then, is to demonstrate the importance of placing the genocide and its resultant trauma in a broader historical context, with a view to establishing that it is shortsighted to ignore the impact of pre- and post-genocide trauma on the Rwandan people when discussing itsembabwoko. Though this has been achieved in socio-historical studies, such as Mahmood Mamdani’s When Victims Become Killers: Colonialism, Nativism, and the Genocide in Rwanda, very little has been produced on literary and cinematic representations of the genocide. , Thesis (MA) -- Faculty of Humanities, Literary Studies in English 2023
- Full Text:
- Date Issued: 2023-10-13
Technological pedagogical content knowledge development: investigating secondary school teachers' integration and use of technology during emergency remote teaching in Endola education circuit
- Authors: Munyanyo, Johanna
- Date: 2023-10
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423882 , vital:72101
- Description: The Covid-19 pandemic has created the largest disruption of education systems in human history. The closure of schools and other learning spaces has impacted billions of learners worldwide. The mitigative measures and many new standard operating procedures have brought restrictions and many challenges. The face-to-face traditional teaching method lost its value, and teaching shifted to distance through the integration of technologies. The integration of technologies necessitated the emergency remote teaching process, as it is one of the distance teaching modes that can make teaching possible even for less technologically privileged nations. Literature has shown that the integration and usage of technology during teaching support the development of technological pedagogical and content knowledge (TPACK) of teachers. This study, therefore, sought to investigate how the integration and use of technology during the emergency remote teaching of Covid-19 developed the secondary school teachers’ technological pedagogical and content knowledge. The study is underpinned by an interpretive paradigm, and a qualitative case study approach was employed. It was conducted in seven secondary schools in the Endola education circuit, Ohangwena region, with the purposeful participation of twenty-six secondary school teachers. Data was collected using semi-structured questionnaires and semi-structured interviews. The study was informed by Vygotsky’s (1978) sociocultural theory together with the TPACK framework of Thompson and Mishra (2007) as both theoretical and analytical frameworks. The study's results showed that teachers made use of existing technological resources to sustain their teaching efforts during ERT. They encountered various challenges, including a lack of technological expertise (knowledge) among both teachers and learners. The shift to virtual instruction during ERT supported teachers in developing proficient technological pedagogical content knowledge. This research concludes that schools possess the necessary technological infrastructure to enable teachers to incorporate technology into their teaching methods. Furthermore, it highlights that teachers generally hold favourable attitudes toward integrating technology into their instruction. Nevertheless, it recommends that there is a need for improving both in-service and pre-service teachers’ training and support for effectively teaching in online and blended learning environments. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10
- Authors: Munyanyo, Johanna
- Date: 2023-10
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423882 , vital:72101
- Description: The Covid-19 pandemic has created the largest disruption of education systems in human history. The closure of schools and other learning spaces has impacted billions of learners worldwide. The mitigative measures and many new standard operating procedures have brought restrictions and many challenges. The face-to-face traditional teaching method lost its value, and teaching shifted to distance through the integration of technologies. The integration of technologies necessitated the emergency remote teaching process, as it is one of the distance teaching modes that can make teaching possible even for less technologically privileged nations. Literature has shown that the integration and usage of technology during teaching support the development of technological pedagogical and content knowledge (TPACK) of teachers. This study, therefore, sought to investigate how the integration and use of technology during the emergency remote teaching of Covid-19 developed the secondary school teachers’ technological pedagogical and content knowledge. The study is underpinned by an interpretive paradigm, and a qualitative case study approach was employed. It was conducted in seven secondary schools in the Endola education circuit, Ohangwena region, with the purposeful participation of twenty-six secondary school teachers. Data was collected using semi-structured questionnaires and semi-structured interviews. The study was informed by Vygotsky’s (1978) sociocultural theory together with the TPACK framework of Thompson and Mishra (2007) as both theoretical and analytical frameworks. The study's results showed that teachers made use of existing technological resources to sustain their teaching efforts during ERT. They encountered various challenges, including a lack of technological expertise (knowledge) among both teachers and learners. The shift to virtual instruction during ERT supported teachers in developing proficient technological pedagogical content knowledge. This research concludes that schools possess the necessary technological infrastructure to enable teachers to incorporate technology into their teaching methods. Furthermore, it highlights that teachers generally hold favourable attitudes toward integrating technology into their instruction. Nevertheless, it recommends that there is a need for improving both in-service and pre-service teachers’ training and support for effectively teaching in online and blended learning environments. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10
A compliance framework for IT governance adoption and use by state-owned entities in South Africa
- Authors: Nxozi, Monelo
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/419244 , vital:71628
- Description: Embargoed. Possible release date in early 2025. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2023
- Full Text:
- Date Issued: 2023-03-31
- Authors: Nxozi, Monelo
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/419244 , vital:71628
- Description: Embargoed. Possible release date in early 2025. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2023
- Full Text:
- Date Issued: 2023-03-31
A native weevil and an exotic planthopper: investigating potential biological control agents for nymphaea mexicana zuccarini (nymphaeaceae) and its hybrids in South Africa
- Authors: Reid, Megan Kim
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422554 , vital:71957 , DOI 10.21504/10962/422554
- Description: Nymphaea mexicana Zuccarini (Nymphaeaceae) is an invasive plant originating from southern USA and Mexico that has become problematic in South Africa, invading several water bodies around the country. Manual removal of this plant is very labour intensive and is not cost efficient or effective for long term control, while the use of herbicides is damaging to the environment and expensive. Consequently, this plant is a desirable candidate for biological control, which takes advantage of enemy release of the target weed and aims to re-establish population suppression induced by host specific natural enemies. Initiating biological control requires that several steps are followed to maximise the success of the programme, and the first few of these, including overseas surveys in the native range of the plant, have already been completed. This thesis aimed to continue biological control research for this species to take further steps at effectively managing the plant. Firstly, pre-release surveys in the invaded range are necessary to: determine what factors (including enemy release) contribute to the invasiveness of the target weed; establish a baseline of information to allow for comparison after biological control agents have been released; and identify any insect herbivores that may already be present in the country. The pre-release surveys conducted in this study revealed useful information about N. mexicana invasions in South Africa and provided evidence that enemy release is applicable to this case. However, these studies determined that a native weevil, Bagous longulus Gyllenhal (Coleoptera: Curculionidae), has expanded its host range to include the exotic N. mexicana at three sites, and may thus have potential for management of the species through augmentative releases. The invasion of N. mexicana in South Africa is further complicated by the presence of several Nymphaea hybrids originating from a complex history of horticultural trade. Although previous research has shown that several hybrid groups are present in South Africa, their parentage is not known. As biological control requires the use of host specific insects adapted to overcome the unique chemical and morphological defences utilised by plant species, hybrids are notoriously difficult to manage because they possess intermediate characters inherited from parent species to which natural enemies may not have adapted. Although biological control of hybrids is challenging, other case studies have demonstrated that it is possible to find suitable agents, but the chances of success are increased if putative parents of the hybrids are known so that they can be surveyed for natural enemies. Further molecular studies including possible parents of the Nymphaea hybrids in South Africa were thus carried out in this thesis to focus future surveying efforts. Two main hybrid groups were identified with genetic similarity to two tested putative Nymphaea parents, and this will allow further investigations of these species to improve the chances of successfully managing these hybrid groups. Some of the tested hybrids showed genetic contributions from multiple groups, some of which were unidentified, so it is necessary to prioritise the most problematic hybrids for biological control. With more insight into the genetic makeup of the Nymphaea hybrids in South Africa, investigations into the host specificity of potential biological control agents can be conducted. The ideal biological control agent should have a broad enough host range to impact and survive on both N. mexicana and its hybrids, but without a host range so broad that it would pose risk to native South African species. Host specificity trials are thus necessary to determine the suitability of potential agents. The identification of B. longulus feeding on N. mexicana during pre-release surveys motivated further investigations to determine the natural distribution, field host range, and host specificity of B. longulus in experimentally controlled conditions. Further surveys were therefore conducted at native Nymphaea sites around South Africa in addition to host specificity trials using the native Nymphaea nouchali Burm. f. (Nymphaeaceae), two populations of N. mexicana, and a cultivated hybrid. Results from the surveys and host specificity tests suggest that B. longulus is widely distributed across South Africa, is specific to Nymphaea with no observed preference between N. mexicana and the native N. nouchali, and does not perform well on Nymphaea hybrids. Hence, B. longulus is promising for use in new association biological control through augmentative releases but is not suitable for management of hybrids. In addition to the potential use of the South African B. longulus, it is necessary to conduct host specificity trials for natural enemies from the native range of N. mexicana that were prioritised in previous studies. Megamelus toddi Beamer (Hemiptera: Delphacidae) is one such species that was imported into quarantined laboratory conditions from Florida, USA. Host specificity trials were conducted using the same test plants as described for the studies on B. longulus, in addition to multigeneration trials to determine how long M. toddi could survive on non-target host plants. As with the B. longulus studies, no statistically significant differences in preference were observed between N. mexicana and N. nouchali, but M. toddi could not complete development on the test hybrid, indicating that this species is also unsuitable for the management of Nymphaea hybrids. Despite suboptimal plant health, M. toddi completed development for three generations on the native N. nouchali. This lack of host specificity deems M. toddi unsafe for release in South Africa but highlights the importance of following predefined steps to develop a biological control programme. The concluding chapter of this thesis discusses the aforementioned findings in a broader context by considering the driving forces of plant invasions in general and specifically for N. mexicana in South Africa. Case studies are also consulted to provide insight into how to proceed with managing Nymphaea hybrids in South Africa, while the factors governing host specificity and host range expansion are also discussed and considered in the context of B. longulus and M. toddi. Finally, after a consideration of the limitations of these studies, recommendations are made to continue the development of biological control for N. mexicana in South Africa. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-03-31
- Authors: Reid, Megan Kim
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422554 , vital:71957 , DOI 10.21504/10962/422554
- Description: Nymphaea mexicana Zuccarini (Nymphaeaceae) is an invasive plant originating from southern USA and Mexico that has become problematic in South Africa, invading several water bodies around the country. Manual removal of this plant is very labour intensive and is not cost efficient or effective for long term control, while the use of herbicides is damaging to the environment and expensive. Consequently, this plant is a desirable candidate for biological control, which takes advantage of enemy release of the target weed and aims to re-establish population suppression induced by host specific natural enemies. Initiating biological control requires that several steps are followed to maximise the success of the programme, and the first few of these, including overseas surveys in the native range of the plant, have already been completed. This thesis aimed to continue biological control research for this species to take further steps at effectively managing the plant. Firstly, pre-release surveys in the invaded range are necessary to: determine what factors (including enemy release) contribute to the invasiveness of the target weed; establish a baseline of information to allow for comparison after biological control agents have been released; and identify any insect herbivores that may already be present in the country. The pre-release surveys conducted in this study revealed useful information about N. mexicana invasions in South Africa and provided evidence that enemy release is applicable to this case. However, these studies determined that a native weevil, Bagous longulus Gyllenhal (Coleoptera: Curculionidae), has expanded its host range to include the exotic N. mexicana at three sites, and may thus have potential for management of the species through augmentative releases. The invasion of N. mexicana in South Africa is further complicated by the presence of several Nymphaea hybrids originating from a complex history of horticultural trade. Although previous research has shown that several hybrid groups are present in South Africa, their parentage is not known. As biological control requires the use of host specific insects adapted to overcome the unique chemical and morphological defences utilised by plant species, hybrids are notoriously difficult to manage because they possess intermediate characters inherited from parent species to which natural enemies may not have adapted. Although biological control of hybrids is challenging, other case studies have demonstrated that it is possible to find suitable agents, but the chances of success are increased if putative parents of the hybrids are known so that they can be surveyed for natural enemies. Further molecular studies including possible parents of the Nymphaea hybrids in South Africa were thus carried out in this thesis to focus future surveying efforts. Two main hybrid groups were identified with genetic similarity to two tested putative Nymphaea parents, and this will allow further investigations of these species to improve the chances of successfully managing these hybrid groups. Some of the tested hybrids showed genetic contributions from multiple groups, some of which were unidentified, so it is necessary to prioritise the most problematic hybrids for biological control. With more insight into the genetic makeup of the Nymphaea hybrids in South Africa, investigations into the host specificity of potential biological control agents can be conducted. The ideal biological control agent should have a broad enough host range to impact and survive on both N. mexicana and its hybrids, but without a host range so broad that it would pose risk to native South African species. Host specificity trials are thus necessary to determine the suitability of potential agents. The identification of B. longulus feeding on N. mexicana during pre-release surveys motivated further investigations to determine the natural distribution, field host range, and host specificity of B. longulus in experimentally controlled conditions. Further surveys were therefore conducted at native Nymphaea sites around South Africa in addition to host specificity trials using the native Nymphaea nouchali Burm. f. (Nymphaeaceae), two populations of N. mexicana, and a cultivated hybrid. Results from the surveys and host specificity tests suggest that B. longulus is widely distributed across South Africa, is specific to Nymphaea with no observed preference between N. mexicana and the native N. nouchali, and does not perform well on Nymphaea hybrids. Hence, B. longulus is promising for use in new association biological control through augmentative releases but is not suitable for management of hybrids. In addition to the potential use of the South African B. longulus, it is necessary to conduct host specificity trials for natural enemies from the native range of N. mexicana that were prioritised in previous studies. Megamelus toddi Beamer (Hemiptera: Delphacidae) is one such species that was imported into quarantined laboratory conditions from Florida, USA. Host specificity trials were conducted using the same test plants as described for the studies on B. longulus, in addition to multigeneration trials to determine how long M. toddi could survive on non-target host plants. As with the B. longulus studies, no statistically significant differences in preference were observed between N. mexicana and N. nouchali, but M. toddi could not complete development on the test hybrid, indicating that this species is also unsuitable for the management of Nymphaea hybrids. Despite suboptimal plant health, M. toddi completed development for three generations on the native N. nouchali. This lack of host specificity deems M. toddi unsafe for release in South Africa but highlights the importance of following predefined steps to develop a biological control programme. The concluding chapter of this thesis discusses the aforementioned findings in a broader context by considering the driving forces of plant invasions in general and specifically for N. mexicana in South Africa. Case studies are also consulted to provide insight into how to proceed with managing Nymphaea hybrids in South Africa, while the factors governing host specificity and host range expansion are also discussed and considered in the context of B. longulus and M. toddi. Finally, after a consideration of the limitations of these studies, recommendations are made to continue the development of biological control for N. mexicana in South Africa. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-03-31
A statistical study of travelling ionospheric disturbances over the African-European and American sectors
- Authors: Thaganyana, Golekamang Piet
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422541 , vital:71956 , DOI 10.21504/10962/422543
- Description: This research presents a long-term statistical study of travelling ionospheric disturbances (TIDs) of low- and high-latitude origin over the American and African-European sectors between 2010 and 2018. The TIDs of low latitude origin (hereafter known as poleward TIDs) were studied in both quiet and disturbed conditions, whereas the equatorward TIDs were only studied during quiet conditions. The Kp > 4 and Dst_ -50 nT was used as a criterion for geomagnetic disturbed conditions, while the four geomagnetically quiet days were selected each month based on Kp < 3. Observations of TIDs are made using Global Navigational Satellite Systems (GNSS) total electron content derived data. During quiet conditions, seven and two transhemispheric TIDs were identified over the African-European and American sectors, respectively. The observed TIDs originated from the wintertime hemisphere and propagated into the summertime hemisphere. The horizontal velocity, periods, and horizontal wavelengths of TIDs are in range of cH = 120-274 m/s, 48-80 min and _H = 379-1104 km, respectively. These quiet-time equatorward TIDs have been associated with tertiary gravity waves (GWs) from the dissipation of secondary GWs which are in turn generated from the dissipation of mountain waves (MWs) as a result of excited orographic forcing. The poleward TIDs during geomagnetically quiet conditions over the African and American sectors occur mainly during local daytime. Poleward TIDs were observed mostly in the African-European sector than the American sector. Their horizontal propagation velocities and periods range between 129-280 m/s and 39-70 min over African-European and American sectors. Although the mechanisms responsible for launching quiet-time poleward TIDs have not been established in this study, lower atmospheric processes such as convection systems, sudden stratospheric warming and cold weather fronts may have a role in their generation. During geomagnetic storms in the African sector, almost all poleward TIDs (with the exception of two cases) during the main phase were large-scale with horizontal velocities and periods ranging from 250-503 m/s and 30 min to 2 hours. During recovery phase, poleward TIDs fall under the category of medium scale. In the American sector, the majority of poleward TIDs occurred during the storm's main phase, as opposed to the African-European sector, which experienced a significant number of poleward TIDs during the recovery phase. The periods and horizontal velocities of TIDs range from 45 min-1.5 h and 180-296 m/s during main phase. During the recovery phase, the horizontal velocity and period range from 177-271 m/s and 40-1.5 h, respectively. Overall, it has been shown that statistically, changes in equatorial electrodynamics related to enhanced eastward electric _eld and hence increased equatorial electrojet (vertical E_B drift) correlates highly with the reported poleward TIDs. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2023
- Full Text:
- Date Issued: 2023-03-31
- Authors: Thaganyana, Golekamang Piet
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422541 , vital:71956 , DOI 10.21504/10962/422543
- Description: This research presents a long-term statistical study of travelling ionospheric disturbances (TIDs) of low- and high-latitude origin over the American and African-European sectors between 2010 and 2018. The TIDs of low latitude origin (hereafter known as poleward TIDs) were studied in both quiet and disturbed conditions, whereas the equatorward TIDs were only studied during quiet conditions. The Kp > 4 and Dst_ -50 nT was used as a criterion for geomagnetic disturbed conditions, while the four geomagnetically quiet days were selected each month based on Kp < 3. Observations of TIDs are made using Global Navigational Satellite Systems (GNSS) total electron content derived data. During quiet conditions, seven and two transhemispheric TIDs were identified over the African-European and American sectors, respectively. The observed TIDs originated from the wintertime hemisphere and propagated into the summertime hemisphere. The horizontal velocity, periods, and horizontal wavelengths of TIDs are in range of cH = 120-274 m/s, 48-80 min and _H = 379-1104 km, respectively. These quiet-time equatorward TIDs have been associated with tertiary gravity waves (GWs) from the dissipation of secondary GWs which are in turn generated from the dissipation of mountain waves (MWs) as a result of excited orographic forcing. The poleward TIDs during geomagnetically quiet conditions over the African and American sectors occur mainly during local daytime. Poleward TIDs were observed mostly in the African-European sector than the American sector. Their horizontal propagation velocities and periods range between 129-280 m/s and 39-70 min over African-European and American sectors. Although the mechanisms responsible for launching quiet-time poleward TIDs have not been established in this study, lower atmospheric processes such as convection systems, sudden stratospheric warming and cold weather fronts may have a role in their generation. During geomagnetic storms in the African sector, almost all poleward TIDs (with the exception of two cases) during the main phase were large-scale with horizontal velocities and periods ranging from 250-503 m/s and 30 min to 2 hours. During recovery phase, poleward TIDs fall under the category of medium scale. In the American sector, the majority of poleward TIDs occurred during the storm's main phase, as opposed to the African-European sector, which experienced a significant number of poleward TIDs during the recovery phase. The periods and horizontal velocities of TIDs range from 45 min-1.5 h and 180-296 m/s during main phase. During the recovery phase, the horizontal velocity and period range from 177-271 m/s and 40-1.5 h, respectively. Overall, it has been shown that statistically, changes in equatorial electrodynamics related to enhanced eastward electric _eld and hence increased equatorial electrojet (vertical E_B drift) correlates highly with the reported poleward TIDs. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2023
- Full Text:
- Date Issued: 2023-03-31
Characterization of Trypanosoma brucei Sti1 and its interactions with Trypanosoma brucei Hsp83 and human Hsp90
- Authors: Jamabo, Miebaka
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422629 , vital:71963 , DOI 10.21504/10962/422629
- Description: Neglected tropical diseases continue to pose global concern due to their impact on health and socio-economic status of developing countries in sub-Saharan Africa. African trypanosomiasis is one of the neglected tropical diseases caused by the kinetoplastid flagellate parasite Trypanosoma brucei (T. brucei). The disease is fatal if untreated and the toolbox to combat the disease has been plagued with many difficulties such as drug resistance, toxic chemotherapeutics, and cumbersome drug delivery processes. In recent years, the disease has received attention from organizations such as the Drugs for Neglected Diseases initiative (DNDi) in partnership with WHO as well as academia and industry to provide alternatives to the existing drugs as part of a targeted approach to eliminate human African trypanosomiasis by 2030. The life cycle of the T. brucei parasite requires that it transitions between a cold-blooded vector (the tsetse fly) and a human host. To survive this extreme environmental change and maintain its infectious cycle, the parasite has evolved an arsenal of tools which include a strong immune evasion technique and a robust molecular chaperone system. Heat shock protein 90 (Hsp90) is one of the most abundant eukaryotic molecular chaperones that has been extensively studied in many organisms. It is indispensable for maintaining proteostasis in some organisms and its inhibition is currently being explored as a drug target for cancer and other parasitic diseases. In T. brucei, cytosolic Hsp90 is specifically referred to as Hsp83 due to variations in the sizes amongst different orthologues. Hsp90 is present in high levels in all stages of the T. brucei cell cycle both constitutively and on exposure to stress. To function in the cell, Hsp90 is dependent on co-chaperones, one of which can be found in most organisms, namely, the stress-inducible protein 1 (Sti1). The Hsp90-Sti1 interaction was shown to be crucial for growth in the intracellular kinetoplastid parasite, Leishmania donovani. However, this partnership has not been explored in the extracellular parasite T. brucei. To analyse the interaction of Hsp90 with Sti1 in T. brucei, this study combined in silico, in vitro and in vivo tools. In silico analyses of the Hsp90 complement in T. brucei revealed the presence of twelve putative Hsp90 genes, ten of which code for the cytosolic protein and are arranged in tandem in a head to tail fashion on the same chromosome. One gene each was found for the mitochondrial and ER paralogues of Hsp90, similar to all other species analysed. Eight putative co-chaperones specific to T. brucei were also discovered: six tetratricopeptide repeat domain (TPR) containing co-chaperones and two non-TPR containing co-chaperones. Structural and evolutionary analysis also confirmed that the domains were conserved across the species analysed. T. brucei Sti1 (TbSti1), T. brucei cytosolic Hsp90 (TbHsp83) and human cytosolic Hsp90 (hHsp90) were heterologously overproduced in E. coli and purified using nickel affinity chromatography. With specific antibodies, the expression and localization of the proteins were confirmed. TbSti1 showed strong affinity to the Hsp90s in the nanomolar range, with higher affinity for hHsp90 compared to TbHsp83. TbHsp83 and hHsp90 showed typical chaperone properties by suppressing the aggregation of thermolabile substrate MDH at equimolar concentrations and both chaperones had potent ATP hydrolysis activity. TbSti1, on the other hand, showed no MDH suppression activity and did not affect the ATP hydrolysis activity of TbHsp83 or hHsp90. Ex-vivo experiments using HeLa CRISPR Hop knockout (KO) human cell lines transfected with pcDNA3.1(+)HA-TbSti1 revealed TbSti1 also localized to the cytoplasm. The transfected cells showed a distinct fibroblast-like morphology which was different from the circular morphology seen in the Hop KO untransfected and wild type untransfected cells. Finally, co-immunoprecipitation studies revealed that TbSti1 co-immunoprecipitated with hHsp90. These results show the first characterization of the TbHsp83-TbSti1 partnership in T. brucei. The strong association between both proteins suggests a functional role for this partnership in T. brucei and could provide an updated context for understanding Trypanosome brucei biology. , Thesis (PhD) -- Faculty of Science, Biotechnology and Innovation Centre, 2023
- Full Text:
- Date Issued: 2023-03-31
- Authors: Jamabo, Miebaka
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422629 , vital:71963 , DOI 10.21504/10962/422629
- Description: Neglected tropical diseases continue to pose global concern due to their impact on health and socio-economic status of developing countries in sub-Saharan Africa. African trypanosomiasis is one of the neglected tropical diseases caused by the kinetoplastid flagellate parasite Trypanosoma brucei (T. brucei). The disease is fatal if untreated and the toolbox to combat the disease has been plagued with many difficulties such as drug resistance, toxic chemotherapeutics, and cumbersome drug delivery processes. In recent years, the disease has received attention from organizations such as the Drugs for Neglected Diseases initiative (DNDi) in partnership with WHO as well as academia and industry to provide alternatives to the existing drugs as part of a targeted approach to eliminate human African trypanosomiasis by 2030. The life cycle of the T. brucei parasite requires that it transitions between a cold-blooded vector (the tsetse fly) and a human host. To survive this extreme environmental change and maintain its infectious cycle, the parasite has evolved an arsenal of tools which include a strong immune evasion technique and a robust molecular chaperone system. Heat shock protein 90 (Hsp90) is one of the most abundant eukaryotic molecular chaperones that has been extensively studied in many organisms. It is indispensable for maintaining proteostasis in some organisms and its inhibition is currently being explored as a drug target for cancer and other parasitic diseases. In T. brucei, cytosolic Hsp90 is specifically referred to as Hsp83 due to variations in the sizes amongst different orthologues. Hsp90 is present in high levels in all stages of the T. brucei cell cycle both constitutively and on exposure to stress. To function in the cell, Hsp90 is dependent on co-chaperones, one of which can be found in most organisms, namely, the stress-inducible protein 1 (Sti1). The Hsp90-Sti1 interaction was shown to be crucial for growth in the intracellular kinetoplastid parasite, Leishmania donovani. However, this partnership has not been explored in the extracellular parasite T. brucei. To analyse the interaction of Hsp90 with Sti1 in T. brucei, this study combined in silico, in vitro and in vivo tools. In silico analyses of the Hsp90 complement in T. brucei revealed the presence of twelve putative Hsp90 genes, ten of which code for the cytosolic protein and are arranged in tandem in a head to tail fashion on the same chromosome. One gene each was found for the mitochondrial and ER paralogues of Hsp90, similar to all other species analysed. Eight putative co-chaperones specific to T. brucei were also discovered: six tetratricopeptide repeat domain (TPR) containing co-chaperones and two non-TPR containing co-chaperones. Structural and evolutionary analysis also confirmed that the domains were conserved across the species analysed. T. brucei Sti1 (TbSti1), T. brucei cytosolic Hsp90 (TbHsp83) and human cytosolic Hsp90 (hHsp90) were heterologously overproduced in E. coli and purified using nickel affinity chromatography. With specific antibodies, the expression and localization of the proteins were confirmed. TbSti1 showed strong affinity to the Hsp90s in the nanomolar range, with higher affinity for hHsp90 compared to TbHsp83. TbHsp83 and hHsp90 showed typical chaperone properties by suppressing the aggregation of thermolabile substrate MDH at equimolar concentrations and both chaperones had potent ATP hydrolysis activity. TbSti1, on the other hand, showed no MDH suppression activity and did not affect the ATP hydrolysis activity of TbHsp83 or hHsp90. Ex-vivo experiments using HeLa CRISPR Hop knockout (KO) human cell lines transfected with pcDNA3.1(+)HA-TbSti1 revealed TbSti1 also localized to the cytoplasm. The transfected cells showed a distinct fibroblast-like morphology which was different from the circular morphology seen in the Hop KO untransfected and wild type untransfected cells. Finally, co-immunoprecipitation studies revealed that TbSti1 co-immunoprecipitated with hHsp90. These results show the first characterization of the TbHsp83-TbSti1 partnership in T. brucei. The strong association between both proteins suggests a functional role for this partnership in T. brucei and could provide an updated context for understanding Trypanosome brucei biology. , Thesis (PhD) -- Faculty of Science, Biotechnology and Innovation Centre, 2023
- Full Text:
- Date Issued: 2023-03-31
Economically important cephalopods of southern Angola, with a focus on the artisanal jig fishery
- Vázquez Morán, Chénelle Lesley
- Authors: Vázquez Morán, Chénelle Lesley
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422529 , vital:71955 , DOI 10.21504/10962/422529
- Description: The global decline in marine finfish stocks has been met with a concomitant expansion of fisheries for cephalopods. Despite the increase in the exploitation and commercialization of cephalopods, there is a dearth of scientific information for over 90% of the extant species and this is even more marked in the developing world. Angolan capture fisheries production noted a tenfold increase in cephalopod landings between 1994 and 2003. One of the important fisheries is a cephalopod directed jig fishery that targets the squid Loligo reynaudii and the cuttlefish Sepia vermiculata in southern Angola, however, there is a complete lack of socio-ecological information available for this fishery. Hence the aim of this thesis was to provide basic biological and demographic information on L. reynaudii and S. vermiculata distributed off the coast of southern Angola, assess the importance and dependence of local artisanal fishers on these two species and examine the current management strategies and policies in the region This study found that the artisanal cephalopod jig fishery is critical for the livelihoods of the coastal communities of southern Angola, particularly due to the limited alternative income generating opportunities available. The cephalopod jig fishery is highly labour intensive, with fishers spending a considerable amount of time per day, drifting over known fishing grounds. Catch composition of the artisanal jig fishery indicated that squid is the dominant species within the fishery, in terms of numerical abundance and weight. The productivity and progression of the fishery is hampered by a number of ecological, socio-economic and governance constraints, as highlighted by socio-economic surveys conducted with local squid fishers. Such constraints include, but are not limited to declining catches, increased negative interactions with seals, increased inter-sector competition, lack of infrastructure, poor quality fishing equipment as well as a lack of communication and support from government officials. To examine aspects of the biology and demography of L. reynaudii, whole specimens were collected monthly, from the two primary fishing areas in southern Angola; Namibe and Tombua, during two main sampling periods, June 2008 – May 2009 (Period 1) and June 2014 – May 2015 (Period 2). Male L. reynaudii were found to be significantly larger in size and weight than females, however both the average and maximum dorsal mantle length (DML) decreased between sampling periods. Length-at-50% maturity was larger for male L. reynaudii (170.47 mm DML – 1st period, 165.44 mm DML – 2nd period) than female L. reynaudii (114.71 mm DML – 1st period, 109.43 mm DML – 2nd period). Gonadosomatic indices (GSI) varied significantly during month and season for both sexes. Peak GSI coincided with a low catches in the artisanal jig fishery suggesting that the population may undergo a spawning migration away from fishing grounds, during late spring and summer. The theory of a seasonal spawning migration is further supported in this study by the low abundance of juvenile and sub-adult L, reynaudii collected during the study, along with the inability to detect egg beds in known fishing grounds. Stomach content analysis indicated that teleosts were the most important dietary item (66.3% F of the stomach contents). Trachurus capensis and Engraulis encrasicolus are both highly abundant small pelagic fishes in the cold nutrient rich waters of the Benguela Current and dominated the diet of sampled squid during autumn and winter months. It is likely that the prevalence of large, adult squid off the coast of Angola, as observed within the current study, may be ascribed to the suitable environmental conditions and the abundance of suitable prey. The results from the current study indicate that the southern Angolan subpopulation reveals similarities to that of the West Coast subpopulation of squid in South Africa, with regards to demographics and reproductive characteristics. It is likely that the population in southern Angola is an extension of the South African subpopulation of L. reynaudii on the western extremities. To examine the basic population biology and ecology of S. vermiculata off southern Angola whole specimens were collected from the fishery between December 2014 and April 2015. Morphological results indicate clear sexual dimorphism in soft part characteristics, cuttlebone and beak morphometry. Length-at-50% maturity was smaller in male S. vermiculata (217.53 mm DML) than female S. vermiculata (231.13 mm DML), although these differences were not significant. Stomach content analysis indicated that S. vermiculata predominantly fed on teleost species which were found within 64.5% of stomachs. Teleosts were more dominant in the diet of male S. vermiculata (78.6% F) than female S. vermiculata (53.0% F), which ate a more varied diet including crustaceans (41.2% F) and cephalopods (17.7% F). Availability and abundance of cuttlefish in Namibe indicates that the species may undergo a spatio-temporal shift in distribution, with majority of the artisanal catches of S. vermiculata occurring during summer months. The results from the current study highlights the fisheries potential of L. reynaudii and S. vermiculata and the dependence of artisanal fishers in southern Angola on cephalopods, and more specifically squid. The development of sustainable fisheries management strategies for the artisanal cephalopod jig fishery is critical, particularly as the global exploitation of cephalopods continues to increase with declining finfish populations. Failure to implement management strategies may remove this critical economic safety net for vulnerable coastal communities which have little alternative livelihood opportunities. Ongoing ecological research, a co-management approach and an increased consideration of local ecological knowledge will assist in designing appropriate management plans for the southern Angolan cephalopod jig fishery. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-03-31
- Authors: Vázquez Morán, Chénelle Lesley
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422529 , vital:71955 , DOI 10.21504/10962/422529
- Description: The global decline in marine finfish stocks has been met with a concomitant expansion of fisheries for cephalopods. Despite the increase in the exploitation and commercialization of cephalopods, there is a dearth of scientific information for over 90% of the extant species and this is even more marked in the developing world. Angolan capture fisheries production noted a tenfold increase in cephalopod landings between 1994 and 2003. One of the important fisheries is a cephalopod directed jig fishery that targets the squid Loligo reynaudii and the cuttlefish Sepia vermiculata in southern Angola, however, there is a complete lack of socio-ecological information available for this fishery. Hence the aim of this thesis was to provide basic biological and demographic information on L. reynaudii and S. vermiculata distributed off the coast of southern Angola, assess the importance and dependence of local artisanal fishers on these two species and examine the current management strategies and policies in the region This study found that the artisanal cephalopod jig fishery is critical for the livelihoods of the coastal communities of southern Angola, particularly due to the limited alternative income generating opportunities available. The cephalopod jig fishery is highly labour intensive, with fishers spending a considerable amount of time per day, drifting over known fishing grounds. Catch composition of the artisanal jig fishery indicated that squid is the dominant species within the fishery, in terms of numerical abundance and weight. The productivity and progression of the fishery is hampered by a number of ecological, socio-economic and governance constraints, as highlighted by socio-economic surveys conducted with local squid fishers. Such constraints include, but are not limited to declining catches, increased negative interactions with seals, increased inter-sector competition, lack of infrastructure, poor quality fishing equipment as well as a lack of communication and support from government officials. To examine aspects of the biology and demography of L. reynaudii, whole specimens were collected monthly, from the two primary fishing areas in southern Angola; Namibe and Tombua, during two main sampling periods, June 2008 – May 2009 (Period 1) and June 2014 – May 2015 (Period 2). Male L. reynaudii were found to be significantly larger in size and weight than females, however both the average and maximum dorsal mantle length (DML) decreased between sampling periods. Length-at-50% maturity was larger for male L. reynaudii (170.47 mm DML – 1st period, 165.44 mm DML – 2nd period) than female L. reynaudii (114.71 mm DML – 1st period, 109.43 mm DML – 2nd period). Gonadosomatic indices (GSI) varied significantly during month and season for both sexes. Peak GSI coincided with a low catches in the artisanal jig fishery suggesting that the population may undergo a spawning migration away from fishing grounds, during late spring and summer. The theory of a seasonal spawning migration is further supported in this study by the low abundance of juvenile and sub-adult L, reynaudii collected during the study, along with the inability to detect egg beds in known fishing grounds. Stomach content analysis indicated that teleosts were the most important dietary item (66.3% F of the stomach contents). Trachurus capensis and Engraulis encrasicolus are both highly abundant small pelagic fishes in the cold nutrient rich waters of the Benguela Current and dominated the diet of sampled squid during autumn and winter months. It is likely that the prevalence of large, adult squid off the coast of Angola, as observed within the current study, may be ascribed to the suitable environmental conditions and the abundance of suitable prey. The results from the current study indicate that the southern Angolan subpopulation reveals similarities to that of the West Coast subpopulation of squid in South Africa, with regards to demographics and reproductive characteristics. It is likely that the population in southern Angola is an extension of the South African subpopulation of L. reynaudii on the western extremities. To examine the basic population biology and ecology of S. vermiculata off southern Angola whole specimens were collected from the fishery between December 2014 and April 2015. Morphological results indicate clear sexual dimorphism in soft part characteristics, cuttlebone and beak morphometry. Length-at-50% maturity was smaller in male S. vermiculata (217.53 mm DML) than female S. vermiculata (231.13 mm DML), although these differences were not significant. Stomach content analysis indicated that S. vermiculata predominantly fed on teleost species which were found within 64.5% of stomachs. Teleosts were more dominant in the diet of male S. vermiculata (78.6% F) than female S. vermiculata (53.0% F), which ate a more varied diet including crustaceans (41.2% F) and cephalopods (17.7% F). Availability and abundance of cuttlefish in Namibe indicates that the species may undergo a spatio-temporal shift in distribution, with majority of the artisanal catches of S. vermiculata occurring during summer months. The results from the current study highlights the fisheries potential of L. reynaudii and S. vermiculata and the dependence of artisanal fishers in southern Angola on cephalopods, and more specifically squid. The development of sustainable fisheries management strategies for the artisanal cephalopod jig fishery is critical, particularly as the global exploitation of cephalopods continues to increase with declining finfish populations. Failure to implement management strategies may remove this critical economic safety net for vulnerable coastal communities which have little alternative livelihood opportunities. Ongoing ecological research, a co-management approach and an increased consideration of local ecological knowledge will assist in designing appropriate management plans for the southern Angolan cephalopod jig fishery. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-03-31
Innovation in ecological restoration techniques: Enhancing Portulacaria afra survivorship in degraded arid thicket
- Authors: Norman, Yondela Masande
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419276 , vital:71630
- Description: The Albany Thicket Biome has undergone extensive degradation over the past century, particularly from overstocking of livestock in the arid types of thicket. The degradation of the biome, coupled with little to no natural recovery, prompted the South African Government to implement the Subtropical Thicket Restoration Programme (STRP) in the early 2000s to rehabilitate degraded thicket using unrooted Portulacaria afra truncheons. The STRP also sought to create job opportunities, bring about social upliftment, promote biodiversity conservation and incentivise farmers and landowners in the region to promote carbon trading and farming of P. afra using carbon credits. However, the survivorship of P. afra planted using the STRP planting protocol has been less than ⁓30% because they are planted in degraded areas, where the truncheons are subjected to harsh biophysical conditions such as hard, capped soil, high soil temperatures, drought and herbivory. The aim of this study, therefore, was to improve the survivorship of P. afra planted in degraded thicket to at least 30%, using modified planting methods. In this study, four treatments were applied in 210 pondings (or micro-dams), each with P. afra planted in them (the first three treatments used rooted cuttings). The first treatment involved watering regimes where pondings were watered at varying frequencies. The second treatment involved planting companion species alongside P. afra while the third treatment involved planting P. afra underneath a nurse canopy. In the fourth treatment, unrooted P. afra truncheons were planted inside pondings. The mean survivorship of the P. afra cuttings was assessed 18 months after planting. The watering regime treatments, including the control, all yielded a survivorship of over 75%, with the significantly highest levels of survivorship being displayed in the weekly watering treatment (90.9 ± 6.8%) (p < 0.01). The companion plant treatment also produced a high mean survivorship of P. afra (94.9 ± 3.6%), significantly higher than that of the nurse plants (87.5 ± 6.3%) (p < 0.01). Among the unrooted truncheons it was found that untreated truncheons had the highest survivorship (76.2 ± 17.6%), with the lowest mean being found in truncheons that were both pruned and scarified (70.8 ± 20.8%), suggesting that this treatment, out of all of them, is the least successful under the prevailing environmental conditions in the study area. However, there was no significant differences among the unrooted truncheon treatments and their respective survivorship values to further substantiate this assertion (p = 0.26). Findings in this study also suggest that planting P. afra cuttings under a nurse plant was ideal for P. afra survivorship due to the nurse plant’s ability to ameliorate the microclimate under which the cuttings can establish and grow. Despite the soil under the nurse canopy having a significantly lower mean soil water potential (-160.9 ± 200.5 kPa), compared to the open areas (-73.4 ± 55.7 kPa) (p = 0.04), the pondings under the nurse canopy still had a lower mean soil temperature (31.4 ± 5.25°C) than the treatments in the open areas (38.5 ± 2.7°C), during the harsh midday sun. These favourable characteristics are reflected in the P. afra cuttings under a nurse canopy having a higher chlorophyll fluorescence (0.76 ± 0.06). compared to those planted in open areas (0.73 ± 0.13), suggesting that the P. afra cuttings in the former treatment had a higher photosynthetic efficiency compared to those in the latter, despite there being no statistically significant difference in chlorophyll fluorescence between the treatments (p = 0.14). Although these findings suggest that applying these modifications to planting P. afra, having achieved its objective of increasing survivorship to well over 50%, is likely to produce favourable results not only in overall survivorship, but also in fast-tracking arid thicket rehabilitation and restoration, further research on these rehabilitation techniques and their effectiveness is required. Furthermore, the downside to these treatments is that they are costly and time consuming, which puts the feasibility of large-scale programmes using these applications into question. Further investigation is required to determine ways in which the cost-effectiveness of these applications can be enhanced. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2023
- Full Text:
- Date Issued: 2023-03-31
- Authors: Norman, Yondela Masande
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419276 , vital:71630
- Description: The Albany Thicket Biome has undergone extensive degradation over the past century, particularly from overstocking of livestock in the arid types of thicket. The degradation of the biome, coupled with little to no natural recovery, prompted the South African Government to implement the Subtropical Thicket Restoration Programme (STRP) in the early 2000s to rehabilitate degraded thicket using unrooted Portulacaria afra truncheons. The STRP also sought to create job opportunities, bring about social upliftment, promote biodiversity conservation and incentivise farmers and landowners in the region to promote carbon trading and farming of P. afra using carbon credits. However, the survivorship of P. afra planted using the STRP planting protocol has been less than ⁓30% because they are planted in degraded areas, where the truncheons are subjected to harsh biophysical conditions such as hard, capped soil, high soil temperatures, drought and herbivory. The aim of this study, therefore, was to improve the survivorship of P. afra planted in degraded thicket to at least 30%, using modified planting methods. In this study, four treatments were applied in 210 pondings (or micro-dams), each with P. afra planted in them (the first three treatments used rooted cuttings). The first treatment involved watering regimes where pondings were watered at varying frequencies. The second treatment involved planting companion species alongside P. afra while the third treatment involved planting P. afra underneath a nurse canopy. In the fourth treatment, unrooted P. afra truncheons were planted inside pondings. The mean survivorship of the P. afra cuttings was assessed 18 months after planting. The watering regime treatments, including the control, all yielded a survivorship of over 75%, with the significantly highest levels of survivorship being displayed in the weekly watering treatment (90.9 ± 6.8%) (p < 0.01). The companion plant treatment also produced a high mean survivorship of P. afra (94.9 ± 3.6%), significantly higher than that of the nurse plants (87.5 ± 6.3%) (p < 0.01). Among the unrooted truncheons it was found that untreated truncheons had the highest survivorship (76.2 ± 17.6%), with the lowest mean being found in truncheons that were both pruned and scarified (70.8 ± 20.8%), suggesting that this treatment, out of all of them, is the least successful under the prevailing environmental conditions in the study area. However, there was no significant differences among the unrooted truncheon treatments and their respective survivorship values to further substantiate this assertion (p = 0.26). Findings in this study also suggest that planting P. afra cuttings under a nurse plant was ideal for P. afra survivorship due to the nurse plant’s ability to ameliorate the microclimate under which the cuttings can establish and grow. Despite the soil under the nurse canopy having a significantly lower mean soil water potential (-160.9 ± 200.5 kPa), compared to the open areas (-73.4 ± 55.7 kPa) (p = 0.04), the pondings under the nurse canopy still had a lower mean soil temperature (31.4 ± 5.25°C) than the treatments in the open areas (38.5 ± 2.7°C), during the harsh midday sun. These favourable characteristics are reflected in the P. afra cuttings under a nurse canopy having a higher chlorophyll fluorescence (0.76 ± 0.06). compared to those planted in open areas (0.73 ± 0.13), suggesting that the P. afra cuttings in the former treatment had a higher photosynthetic efficiency compared to those in the latter, despite there being no statistically significant difference in chlorophyll fluorescence between the treatments (p = 0.14). Although these findings suggest that applying these modifications to planting P. afra, having achieved its objective of increasing survivorship to well over 50%, is likely to produce favourable results not only in overall survivorship, but also in fast-tracking arid thicket rehabilitation and restoration, further research on these rehabilitation techniques and their effectiveness is required. Furthermore, the downside to these treatments is that they are costly and time consuming, which puts the feasibility of large-scale programmes using these applications into question. Further investigation is required to determine ways in which the cost-effectiveness of these applications can be enhanced. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2023
- Full Text:
- Date Issued: 2023-03-31
Phytoplankton communities provide insight into ecosystem functioning of the Agulhas Current system
- Authors: Gibb, Ross-Lynne Alida
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422646 , vital:71965
- Description: Access restricted. Embargoed until 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-03-31
- Authors: Gibb, Ross-Lynne Alida
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422646 , vital:71965
- Description: Access restricted. Embargoed until 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-03-31
Rapid Synthesis of Thiol-Co-Capped CdTe/CdSe/ZnSe Multi-Core-Shell QDs and Their Encapsulation in Liposomes and Chitosan Nanoparticles; Comparative Bio-compatibility Studies Using Hela and Vero Cells
- Authors: Daramola, Olamide Abiodun
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422617 , vital:71962 , DOI 10.21504/10962/422617
- Description: The common method that has been used to reduce the toxicity posed to living cells by CdTe Quantum Dots (QDs) is through the synthesis of CdTe multi-core-shells nanoparticles. In this process, the surface of CdTe QDs is usually coated by less toxic ZnS or ZnSe shells. This heterostructure compound does not only reduce the toxicity of CdTe QDs but can also be used in applications such as deep tissue imaging. The heterostructures can be in numerous forms such as CdTe/CdSe/ZnSe or CdTe/CdSe/ZnS or CdTe/CdS/ZnS multi-core-shell QDs. However, the drawbacks attributed to the fabrication of these compounds is long synthesis times (6- 24 h) in achieving the highest wavelength emission maxima. Others are the use of toxic reagents and poor reproducibility of synthesized materials. An additional problem is that the ZnSe or ZnS coating is insufficient to completely protect the highly toxic Cd metal from escaping into immediate solution. This limits their use in biochemistry and with living systems. Liposomes and biopolymers such as chitosan are known to be environmentally friendly compounds that have been used in various studies as delivery systems for QDs and model drugs for drug delivery applications. They are generally non-toxic and highly bio-compatible. In this study, the rapid synthesis of thiol-co-capped CdTe/CdSe/ZnSe multi-core-shell QDs with a maximum reaction time of 35 mins, gave reliable QDs with emission maxima at 625 nm. The multi-core-shell QDs were encapsulated in two different bio-compatible environments, namely liposome and chitosan nanoparticles (CNP) at 14 different formulations (F) for liposome and 12 different formulations for CNP. Cytotoxicity and florescence imaging studies using HeLa and Vero cells, were used to investigate the improved bio-compatibility. Various characterization techniques were used to elucidate the optical properties, morphology and physico-chemical properties of the QDs and nanocomposites. Two of the best formulations, QD-liposome vesicles (LVs)-F12 and QD-CNP-F9 (with chitosan), demonstrated high loading efficiencies of 42 ± 6 % and 59 ± 5 %, respectively. While the plain CdTe QDs showed high toxicity, some of the encapsulated materials, QD-LVs-F1 and F12, depicted no-toxicity against the cells (IC50 > 0.5 mg/ml). The QDs also retained most of their fluorescence and properties and could easily be tracked in cells and visualized around the nucleus, indicating the successful internalization of the QDs in the cytosol. These results shows that encapsulation of CdTe multi-core-shell QDs in liposomes produce better bio-compatibility compared to multi-core-shell QDs and better than CNP coating. These particles therefore show good promise in cell-labelling, drug delivery studies. Their core-shell nanoparticles have also shown good behavior in enhancing the memory of a device which is based on some recent collaborated works. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-03-31
- Authors: Daramola, Olamide Abiodun
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422617 , vital:71962 , DOI 10.21504/10962/422617
- Description: The common method that has been used to reduce the toxicity posed to living cells by CdTe Quantum Dots (QDs) is through the synthesis of CdTe multi-core-shells nanoparticles. In this process, the surface of CdTe QDs is usually coated by less toxic ZnS or ZnSe shells. This heterostructure compound does not only reduce the toxicity of CdTe QDs but can also be used in applications such as deep tissue imaging. The heterostructures can be in numerous forms such as CdTe/CdSe/ZnSe or CdTe/CdSe/ZnS or CdTe/CdS/ZnS multi-core-shell QDs. However, the drawbacks attributed to the fabrication of these compounds is long synthesis times (6- 24 h) in achieving the highest wavelength emission maxima. Others are the use of toxic reagents and poor reproducibility of synthesized materials. An additional problem is that the ZnSe or ZnS coating is insufficient to completely protect the highly toxic Cd metal from escaping into immediate solution. This limits their use in biochemistry and with living systems. Liposomes and biopolymers such as chitosan are known to be environmentally friendly compounds that have been used in various studies as delivery systems for QDs and model drugs for drug delivery applications. They are generally non-toxic and highly bio-compatible. In this study, the rapid synthesis of thiol-co-capped CdTe/CdSe/ZnSe multi-core-shell QDs with a maximum reaction time of 35 mins, gave reliable QDs with emission maxima at 625 nm. The multi-core-shell QDs were encapsulated in two different bio-compatible environments, namely liposome and chitosan nanoparticles (CNP) at 14 different formulations (F) for liposome and 12 different formulations for CNP. Cytotoxicity and florescence imaging studies using HeLa and Vero cells, were used to investigate the improved bio-compatibility. Various characterization techniques were used to elucidate the optical properties, morphology and physico-chemical properties of the QDs and nanocomposites. Two of the best formulations, QD-liposome vesicles (LVs)-F12 and QD-CNP-F9 (with chitosan), demonstrated high loading efficiencies of 42 ± 6 % and 59 ± 5 %, respectively. While the plain CdTe QDs showed high toxicity, some of the encapsulated materials, QD-LVs-F1 and F12, depicted no-toxicity against the cells (IC50 > 0.5 mg/ml). The QDs also retained most of their fluorescence and properties and could easily be tracked in cells and visualized around the nucleus, indicating the successful internalization of the QDs in the cytosol. These results shows that encapsulation of CdTe multi-core-shell QDs in liposomes produce better bio-compatibility compared to multi-core-shell QDs and better than CNP coating. These particles therefore show good promise in cell-labelling, drug delivery studies. Their core-shell nanoparticles have also shown good behavior in enhancing the memory of a device which is based on some recent collaborated works. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-03-31
South African supratidal microbialites: prokaryote communities, metabolic capabilities, and biogeochemical processes
- Authors: Isemonger, Eric William
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422641 , vital:71964
- Description: Access restricted. Embargoed until 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-03-31
- Authors: Isemonger, Eric William
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422641 , vital:71964
- Description: Access restricted. Embargoed until 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-03-31
The development of ionic zinc(II) phthalocyanines for sono-photodynamic combination therapy of cervical and breast cancer
- Authors: Nene, Lindokuhle Cindy
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422565 , vital:71958 , DOI 10.21504/10962/422565
- Description: This study focuses on the development of the sono-photodynamic combination therapy (SPDT) activity of phthalocyanines (Pcs) on the cervical and breast cancer cell lines in vitro. The SPDT technique utilizes ultrasound in combination with light to elicit cytotoxic effects for cancer eradication. In this work, a selection of tetra-peripherally substituted Zn(II) cationic and zwitterionic Pcs were prepared. The photophysical parameters of the Pcs were determined including their fluorescence behaviours and efficiency of the triplet excited state population. The effects of the ultrasonic parameters (frequencies (MHz) and power (W.cm-2)) on the stability of the Pcs were evaluated. Four parameters were evaluated: Par I (1 MHz: 1 W.cm-2), Par II (1 MHz: 2 W.cm-2), Par III (3 MHz: 1 W.cm-2) and Par IV (3 MHz: 2 W.cm-2). The stability of the Pcs reduced with the increase in the ultrasonic power (for Par II and Par IV). The Par I showed the least degradation compared to the other parameters and was therefore used for the SPDT treatments. The sonodynamic (SDT), photodynamic (PDT) therapy activities of the Pcs were studied and compared to their SPDT efficacies. The Pcs showed reactive oxygen species generation during the SDT, PDT and SPDT treatments. For the SDT and SPDT, singlet oxygen (1O2) and hydroxyl radicals (•OH) were detected. For PDT, only the 1O2 were detected. The cell cytotoxicity studies for the Pcs showed relatively higher therapeutic efficacies for the SDT treatments compared to the PDT treatments, where the SPDT showed higher therapeutic efficacies compared to both the SDT and PDT monotreatments on both the cell lines in vitro. Overall, the combination treatments were better compared to the monotreatments. The activities of the Pcs were compared by their differences in structures, including the type of R-group, type of quaternizing agent and type of nanoparticle conjugates. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-03-31
- Authors: Nene, Lindokuhle Cindy
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422565 , vital:71958 , DOI 10.21504/10962/422565
- Description: This study focuses on the development of the sono-photodynamic combination therapy (SPDT) activity of phthalocyanines (Pcs) on the cervical and breast cancer cell lines in vitro. The SPDT technique utilizes ultrasound in combination with light to elicit cytotoxic effects for cancer eradication. In this work, a selection of tetra-peripherally substituted Zn(II) cationic and zwitterionic Pcs were prepared. The photophysical parameters of the Pcs were determined including their fluorescence behaviours and efficiency of the triplet excited state population. The effects of the ultrasonic parameters (frequencies (MHz) and power (W.cm-2)) on the stability of the Pcs were evaluated. Four parameters were evaluated: Par I (1 MHz: 1 W.cm-2), Par II (1 MHz: 2 W.cm-2), Par III (3 MHz: 1 W.cm-2) and Par IV (3 MHz: 2 W.cm-2). The stability of the Pcs reduced with the increase in the ultrasonic power (for Par II and Par IV). The Par I showed the least degradation compared to the other parameters and was therefore used for the SPDT treatments. The sonodynamic (SDT), photodynamic (PDT) therapy activities of the Pcs were studied and compared to their SPDT efficacies. The Pcs showed reactive oxygen species generation during the SDT, PDT and SPDT treatments. For the SDT and SPDT, singlet oxygen (1O2) and hydroxyl radicals (•OH) were detected. For PDT, only the 1O2 were detected. The cell cytotoxicity studies for the Pcs showed relatively higher therapeutic efficacies for the SDT treatments compared to the PDT treatments, where the SPDT showed higher therapeutic efficacies compared to both the SDT and PDT monotreatments on both the cell lines in vitro. Overall, the combination treatments were better compared to the monotreatments. The activities of the Pcs were compared by their differences in structures, including the type of R-group, type of quaternizing agent and type of nanoparticle conjugates. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-03-31
An analysis of womxn’s understanding of South African public health awareness campaigns’ messages on HIV/AIDS using cognitive interviewing
- Authors: Simpo, Hazel
- Date: 2023-03-30
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408738 , vital:70521
- Description: Besides having the most extensive antiretroviral therapy (ART) treatment programme, South Africa faces the highest epidemic rate, with womxn and children most affected. Several prevention strategies have been implemented to curb the spread of HIV/AIDS in South Africa, including free access to print form awareness campaigns that come through pamphlets, posters and billboards. However, most public health sector awareness and educational programmes carry uniform messages that are then carried out in heterogeneous contexts leading to the miscomprehension of the intended messages. This study aimed to explore womxn’s understanding of public health awareness content on the prevention of HIV/AIDS. The focus was on examining their interpretation of universal HIV/AIDS awareness messages in their heterogeneous contexts, which might provide obstacles to womxn’s reproductive health and well-being using a reproductive justice framework. This study employed a cognitive interviewing methodology to collect data from the participants to obtain information about how participants understand and perceive knowledge and how they arrive at specific answers or judgements. Twenty-eight (28) womxn aged between 18 and 30 years were purposively sampled for this study from four (4) local healthcare facilities in Makhanda: the Grahamstown Municipality (Anglo-African) Clinic, the Joza Clinic, the Settlers Day Hospital and the Raglan Road Clinic. Thematic network analysis (Attride-Stirling, 2001) was used to analyse the data collected from the study. One global theme emerged from the dataset: Barriers to HIV prevention, care and treatment. The barriers were identified mainly due to social constructions of hegemonic masculinity, individual versus cultural expectations, and outdated awareness content. The findings from the study suggest that almost all the challenges that womxn faced in terms of understanding and interpreting the awareness materials stemmed from structural factors in the South African context. The findings also suggest that cognitive interviewing methodology can be reconceptualised as an endeavour that cuts across a wide range of fields. , Thesis (MSocSci) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Date Issued: 2023-03-30
- Authors: Simpo, Hazel
- Date: 2023-03-30
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408738 , vital:70521
- Description: Besides having the most extensive antiretroviral therapy (ART) treatment programme, South Africa faces the highest epidemic rate, with womxn and children most affected. Several prevention strategies have been implemented to curb the spread of HIV/AIDS in South Africa, including free access to print form awareness campaigns that come through pamphlets, posters and billboards. However, most public health sector awareness and educational programmes carry uniform messages that are then carried out in heterogeneous contexts leading to the miscomprehension of the intended messages. This study aimed to explore womxn’s understanding of public health awareness content on the prevention of HIV/AIDS. The focus was on examining their interpretation of universal HIV/AIDS awareness messages in their heterogeneous contexts, which might provide obstacles to womxn’s reproductive health and well-being using a reproductive justice framework. This study employed a cognitive interviewing methodology to collect data from the participants to obtain information about how participants understand and perceive knowledge and how they arrive at specific answers or judgements. Twenty-eight (28) womxn aged between 18 and 30 years were purposively sampled for this study from four (4) local healthcare facilities in Makhanda: the Grahamstown Municipality (Anglo-African) Clinic, the Joza Clinic, the Settlers Day Hospital and the Raglan Road Clinic. Thematic network analysis (Attride-Stirling, 2001) was used to analyse the data collected from the study. One global theme emerged from the dataset: Barriers to HIV prevention, care and treatment. The barriers were identified mainly due to social constructions of hegemonic masculinity, individual versus cultural expectations, and outdated awareness content. The findings from the study suggest that almost all the challenges that womxn faced in terms of understanding and interpreting the awareness materials stemmed from structural factors in the South African context. The findings also suggest that cognitive interviewing methodology can be reconceptualised as an endeavour that cuts across a wide range of fields. , Thesis (MSocSci) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Date Issued: 2023-03-30
Constructions of Ukuyalwa and marriage satisfaction: experiences of Xhosa couples in the Eastern Cape
- Authors: Bikwe, Siphuxolo
- Date: 2023-03-30
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408805 , vital:70527
- Description: Marital satisfaction may be described as the extent to which one’s expectations, desires and needs are being satisfied in their marriage. Studies that concern marital satisfaction provide us with crucial insights into factors that support or compromise the longevity of long-term, committed relationships. Little work has been done in understanding the role of cultural practices in marital satisfaction particularly in Africa, and South Africa more specifically. Ukuyalwa is a Xhosa ritual that takes place during a Xhosa traditional wedding, whereby the bride is introduced to the (traditional) guiding practices of her new home by the women of the family together with her sisters-in-law. This study informs the practice of African psychology as formulated by Ratele (2017b).Critical African psychology as a framework recognizes the construction of culture alongside political, socioeconomic, and historical matrices. These are acknowledged as an important element in psychological theories, methods, and explanations. This research project aimed to identify the discourses that circulate around ukuyalwa as a Xhosa cultural practice and consider the implications for the marital satisfaction of amaXhosa couples. The study interviewed 3 Xhosa couples of varying ages who had been married for different durations to develop an understanding of their experiences of ukuyalwa and marital satisfaction. Data was analyzed using a Foucauldian Discourse Analysis (FDA) which allowed for the identifications of the discourses that the couples used to construct ukuyalwa and marital satisfaction. The couples discursively constructed marriage as ‘divine unity’, ‘unification of families’ and ‘partnership’. Ukuyalwa was constructed as a ‘gendered process’, ideas of tradition and modernity, and a ‘foundation’ also became apparent. Satisfaction was constructed as ‘open communication’ and ‘work’. The couples’ positions shifted in their conversations, where in some instances they were 'learners’, ‘initiates’, and/or ‘passive’, and in other instances, they were ‘in charge’, ‘knowledgeable’, and ‘experts’. The discourses of culture, religion, and partnership circulated prominently in relation to marriage, ukuyalwa, and marital satisfaction. The findings of the study speak to how the couples’ constructions of marriage and cultural customs such as ukuyalwa are valuable as they often inform how couples behave in their marriage relationships and what they regard as satisfactory to them when it comes to marriage. These insights into what informs the couples’ ideas on marriage and satisfaction can be utilised in informing couples therapy interventions. , Thesis (MA) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Date Issued: 2023-03-30
- Authors: Bikwe, Siphuxolo
- Date: 2023-03-30
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408805 , vital:70527
- Description: Marital satisfaction may be described as the extent to which one’s expectations, desires and needs are being satisfied in their marriage. Studies that concern marital satisfaction provide us with crucial insights into factors that support or compromise the longevity of long-term, committed relationships. Little work has been done in understanding the role of cultural practices in marital satisfaction particularly in Africa, and South Africa more specifically. Ukuyalwa is a Xhosa ritual that takes place during a Xhosa traditional wedding, whereby the bride is introduced to the (traditional) guiding practices of her new home by the women of the family together with her sisters-in-law. This study informs the practice of African psychology as formulated by Ratele (2017b).Critical African psychology as a framework recognizes the construction of culture alongside political, socioeconomic, and historical matrices. These are acknowledged as an important element in psychological theories, methods, and explanations. This research project aimed to identify the discourses that circulate around ukuyalwa as a Xhosa cultural practice and consider the implications for the marital satisfaction of amaXhosa couples. The study interviewed 3 Xhosa couples of varying ages who had been married for different durations to develop an understanding of their experiences of ukuyalwa and marital satisfaction. Data was analyzed using a Foucauldian Discourse Analysis (FDA) which allowed for the identifications of the discourses that the couples used to construct ukuyalwa and marital satisfaction. The couples discursively constructed marriage as ‘divine unity’, ‘unification of families’ and ‘partnership’. Ukuyalwa was constructed as a ‘gendered process’, ideas of tradition and modernity, and a ‘foundation’ also became apparent. Satisfaction was constructed as ‘open communication’ and ‘work’. The couples’ positions shifted in their conversations, where in some instances they were 'learners’, ‘initiates’, and/or ‘passive’, and in other instances, they were ‘in charge’, ‘knowledgeable’, and ‘experts’. The discourses of culture, religion, and partnership circulated prominently in relation to marriage, ukuyalwa, and marital satisfaction. The findings of the study speak to how the couples’ constructions of marriage and cultural customs such as ukuyalwa are valuable as they often inform how couples behave in their marriage relationships and what they regard as satisfactory to them when it comes to marriage. These insights into what informs the couples’ ideas on marriage and satisfaction can be utilised in informing couples therapy interventions. , Thesis (MA) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Date Issued: 2023-03-30