Prosecution of forced marriage by international courts and tribunals in light of the principle of legality
- Okeyo, Julian Rebecca Atieno
- Authors: Okeyo, Julian Rebecca Atieno
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/420720 , vital:71772
- Description: Thesis embargoed. Probable release date in 2024. , Thesis (LLM) -- Faculty of Law, Law, 2023
- Full Text:
- Date Issued: 2023-03-29
- Authors: Okeyo, Julian Rebecca Atieno
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/420720 , vital:71772
- Description: Thesis embargoed. Probable release date in 2024. , Thesis (LLM) -- Faculty of Law, Law, 2023
- Full Text:
- Date Issued: 2023-03-29
Leveraging a peer-learning community and expert community members in the integration of indigenous knowledge into the learning and teaching of Grade 10 Chemistry on the rate of reactions
- Authors: Simasiku, Fredrick Simataa
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366211 , vital:65843 , DOI https://doi.org/10.21504/10962/366211
- Description: The integration of indigenous knowledge (IK) in science teaching in Namibia is part of the transformation agenda that hopes to revitalise and make science accessible and relevant to learners’ everyday life experiences. However, there seems to be contradictions between the intended curriculum, the enacted curriculum and the attained curriculum. This disjuncture is exacerbated in part by the fact that science teachers seem to be struggling to be cultural knowledge brokers. It is against this backdrop that this formative interventionist study sought to leverage a peer-learning community and expert community members in the integration of IK into the learning and teaching of Grade 10 Chemistry on the rate of reactions. To achieve this, we mobilised the indigenous technologies of preserving and pounding Mahangu and making Oshikundu to mediate learning of the rate of reactions. The study was guided by the broad overarching research question: How does a peer-learning community and expert community members leverage the integration of indigenous knowledge into the learning and teaching of Grade 10 Chemistry on the rate of reactions? In this study, I used two complementary paradigms, viz. the transformative research paradigm and the indigenous research paradigm. Within these paradigms, I employed a qualitative case study research design using the community of practice and participatory action research as research approaches. Five Grade 10 Chemistry teachers from three schools in the Ohangwena region were involved in this study. Data were generated through semi-structured interviews, co-analysis of curriculum documents, workshop presentations and discussions, practical demonstrations, participatory observation, lesson observation, stimulated recall interviews, and participants’ reflections. Vygotsky’s sociocultural theory and Shulman’s Pedagogical Content Knowledge (PCK) were employed as theoretical frameworks in this study. Additionally, within PCK, Mavhunga and Rollnick’s Topic-Specific Pedagogical Content Knowledge components were used as an analytical framework. I used an inductive-deductive approach to data analysis to come up with sub-themes and themes. The main finding of this study revealed that leveraging a peer-learning community and the expert community members (ECMs) empowered the Chemistry teachers involved in this study to be cultural knowledge brokers and their understanding of how to integrate IK in their teaching improved. Both their subject matter knowledge and pedagogical content knowledge improved through co-developing and enacting exemplar lessons that integrated IK from the expert community members as well as from their own environments. A main insight of this study is that Chemistry teachers should seek opportunities to create peer-learning communities that engage with expert community members who are the custodians of the cultural heritage. The study also shows that this approach will support them to become better cultural knowledge brokers and help their learners bridge the divide between school science and what they have learnt in their homes or community. , Thesis (PhD) -- Faculty of Education, Education, 2023
- Full Text:
- Date Issued: 2023-03-29
- Authors: Simasiku, Fredrick Simataa
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366211 , vital:65843 , DOI https://doi.org/10.21504/10962/366211
- Description: The integration of indigenous knowledge (IK) in science teaching in Namibia is part of the transformation agenda that hopes to revitalise and make science accessible and relevant to learners’ everyday life experiences. However, there seems to be contradictions between the intended curriculum, the enacted curriculum and the attained curriculum. This disjuncture is exacerbated in part by the fact that science teachers seem to be struggling to be cultural knowledge brokers. It is against this backdrop that this formative interventionist study sought to leverage a peer-learning community and expert community members in the integration of IK into the learning and teaching of Grade 10 Chemistry on the rate of reactions. To achieve this, we mobilised the indigenous technologies of preserving and pounding Mahangu and making Oshikundu to mediate learning of the rate of reactions. The study was guided by the broad overarching research question: How does a peer-learning community and expert community members leverage the integration of indigenous knowledge into the learning and teaching of Grade 10 Chemistry on the rate of reactions? In this study, I used two complementary paradigms, viz. the transformative research paradigm and the indigenous research paradigm. Within these paradigms, I employed a qualitative case study research design using the community of practice and participatory action research as research approaches. Five Grade 10 Chemistry teachers from three schools in the Ohangwena region were involved in this study. Data were generated through semi-structured interviews, co-analysis of curriculum documents, workshop presentations and discussions, practical demonstrations, participatory observation, lesson observation, stimulated recall interviews, and participants’ reflections. Vygotsky’s sociocultural theory and Shulman’s Pedagogical Content Knowledge (PCK) were employed as theoretical frameworks in this study. Additionally, within PCK, Mavhunga and Rollnick’s Topic-Specific Pedagogical Content Knowledge components were used as an analytical framework. I used an inductive-deductive approach to data analysis to come up with sub-themes and themes. The main finding of this study revealed that leveraging a peer-learning community and the expert community members (ECMs) empowered the Chemistry teachers involved in this study to be cultural knowledge brokers and their understanding of how to integrate IK in their teaching improved. Both their subject matter knowledge and pedagogical content knowledge improved through co-developing and enacting exemplar lessons that integrated IK from the expert community members as well as from their own environments. A main insight of this study is that Chemistry teachers should seek opportunities to create peer-learning communities that engage with expert community members who are the custodians of the cultural heritage. The study also shows that this approach will support them to become better cultural knowledge brokers and help their learners bridge the divide between school science and what they have learnt in their homes or community. , Thesis (PhD) -- Faculty of Education, Education, 2023
- Full Text:
- Date Issued: 2023-03-29
Nurses’ experiences of an abortion counselling training course and their understandings of quality abortion services
- Authors: Mogonong, Laurah Carolina
- Date: 2023-03-30
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408862 , vital:70532
- Description: This research study focuses on nurses’ experiences of participating in an abortion counselling training programme in the Eastern Cape Province (E.C), using a grounded theory and symbolic interactionism framework. The study aims to investigate how participating in a women-centred abortion counselling training course offered through the Critical Studies in Sexualities and Reproduction research unit may modify or improve nurses’ practice of abortion counselling and understanding of quality abortion services. Through purposive sampling, nine research participants working as abortion providers in EC health care facilities were recruited. Research data were produced using discussions around prior abortion counselling experiences, a reflective activity, power point case presentations conducted within the counselling training, and semi-structured interviews conducted two months after the training with five of the providers. A grounded theory analysis was used to generate themes that highlighted different aspects that enabled or hindered access to quality abortion services. In accordance with prior research, it was revealed that nurses undergo abortion training but there is limited content on abortion counselling training. Findings from this study reveal the modifications of practice and understanding of quality abortion services of nurses who participated in the client-centred abortion counselling training course. Themes of change that emerged from the nurses’ experiences were rendering counselling services in a non- judgemental, non-directive way, being acknowledged and recognized for the services they offer as abortion providers, and accepting that abortion is a reproductive legal right that can be accessed whenever a woman in need of the service requests it. The findings of this research also indicate that, despite the controversy and stigma attached to providing abortion services, the participants were motivated to continue offering abortion services because they felt equipped since undergoing abortion counselling training. The training course improved reported abortion counselling practices, but systematic issues such as lack of managerial support, space for individual counselling and procedure equipment continue to undermine services. , Thesis (MA) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Date Issued: 2023-03-30
- Authors: Mogonong, Laurah Carolina
- Date: 2023-03-30
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408862 , vital:70532
- Description: This research study focuses on nurses’ experiences of participating in an abortion counselling training programme in the Eastern Cape Province (E.C), using a grounded theory and symbolic interactionism framework. The study aims to investigate how participating in a women-centred abortion counselling training course offered through the Critical Studies in Sexualities and Reproduction research unit may modify or improve nurses’ practice of abortion counselling and understanding of quality abortion services. Through purposive sampling, nine research participants working as abortion providers in EC health care facilities were recruited. Research data were produced using discussions around prior abortion counselling experiences, a reflective activity, power point case presentations conducted within the counselling training, and semi-structured interviews conducted two months after the training with five of the providers. A grounded theory analysis was used to generate themes that highlighted different aspects that enabled or hindered access to quality abortion services. In accordance with prior research, it was revealed that nurses undergo abortion training but there is limited content on abortion counselling training. Findings from this study reveal the modifications of practice and understanding of quality abortion services of nurses who participated in the client-centred abortion counselling training course. Themes of change that emerged from the nurses’ experiences were rendering counselling services in a non- judgemental, non-directive way, being acknowledged and recognized for the services they offer as abortion providers, and accepting that abortion is a reproductive legal right that can be accessed whenever a woman in need of the service requests it. The findings of this research also indicate that, despite the controversy and stigma attached to providing abortion services, the participants were motivated to continue offering abortion services because they felt equipped since undergoing abortion counselling training. The training course improved reported abortion counselling practices, but systematic issues such as lack of managerial support, space for individual counselling and procedure equipment continue to undermine services. , Thesis (MA) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Date Issued: 2023-03-30
A Pedagogy of Love: reflections on 25 years of informal vocational education and training practices in the commercial fishing industry in South Africa
- Authors: Ferguson, Robin Anne
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366189 , vital:65841 , DOI https://doi.org/10.21504/10962/366189
- Description: This thesis is a reflection of informal vocational education and training (IVET) practices conducted by the Researcher in the commercial fishing industry between 1995-2021. Fourteen interventions took place during this time which involved several hundred sea-going employees who are disadvantaged by low levels of literacies and low/no Internet Computer Technology connectivity. The Production Programme was chosen as the focus of study and draws upon the influence of the other thirteen programmes. The purpose of the Production Programme was to teach technical fish processing skills to the production management teams and factory hands who work in the factories on board the vessels. The programme ran for five years and evolved through three distinct generations. At the heart of this work lies the question: ‘What made these programmes successful?’ This is an intra-programmatic study and seeks to identify the pedagogical practices which promoted or confounded the efficacy of the Production Programme; and based upon this understanding how such programmes could be improved, transferred, and taken to scale. These questions are both descriptive and explorative in nature. IVET is regarded as training which takes place outside of the formal South African National Qualifications Framework. This work is relevant because approximately 80% of sea-going staff neither finish school, nor get the opportunity of Post School Education and Training by going to a university, a technical institution, or a community college. This statistic is reflected in the general population (Department of Higher Education and Training [DHET], 2022). There is a fine line between being employed and unemployed for people working at this level in the formal economy which makes this project relevant to youth or persons who are ‘not in employment, education or training’ too. This means that for most South African adults IVET presents a significant opportunity for post-school education. Therefore, it is important to answer the questions raised above to rapidly improve inclusion of the majority of South Africans into meaningful education which improves livelihoods. The Theory of Practice Architectures (TPA), from the collection of social-material practice theories, is the conceptual framework for this thesis. The smallest unit of analysis of TPA are practices which may be ‘sayings/thinkings’, ‘doings’, or ‘relatings’. These practices bundle together into practice arrangements and form practice architectures. The reason that TPA was chosen was that practices were the only data available as we (learners, managers, facilitators, and me) knew what we had said/thought or done, and we were aware of the relationships between us over the years as the fourteen interventions played out. Under conventional research circumstances data would be collected in real time, however in this project, most of the data is historical. In addition to the fundamental building blocks of TPA, the theory is embedded in a Theory of Education. There have also been contemporary enhancements to the TPA which were significant to this study, for example, the Ecologies of Practices, a Trellis of Practices which Support Professional Learning, Middle Leadership, Travelling Practices, and moves towards transformative or transgressive education using the TPA in IVET. This is empirical, qualitative research and an ethnographic case study was chosen as the research design which is a methodology particularly suited to answering both descriptive and explorative questions. Nine methods for data collection were used, namely an historical reflective narrative; two focused-group interviews; three individual interviews; four Whatsapp videos; one WhatsApp voice note; two mobisodes; ten questionnaires; 29 documents; and 16 photographs. Because this data was collected under Covid-19 pandemic conditions, two conceptions were employed to guide the generation of data under these uncertain and constrained conditions. These were firstly, the ‘methodology of chance’ which allowed for a ‘methodological agility’; and secondly, the idea of ‘information power’ which is helpful in deciding on how much data is enough. In order to be explicit concerning a key research activity, the approach and method used to review the literature is explicated. Key practices were identified in the data set and described; and then the data was analysed using heuristics provided by TPA theorists. Seven Tables of Invention were used to synthesise the data arising from these practices. An eighth Table of Invention was used to synthesise all the practices and practice arrangements characterised; and to indicate how these evolved over time and space. The data description and analysis is supported by eight Analytic Memos, a comprehensive Data Code Table and a hyperlink to a data repository which provides access to oral and video material. The findings distinguished five key practices and practice arrangements which were: Practices of the Creation of Courseware; Practices of Teaching and Learning; Practices of Assessment; Practices of Love; Practices of Management. The thesis title is reflective of the impact which love has upon the pedagogical process of IVET. Based upon the analysis and synthesis of the corpus of data, practices which either promoted or confounded the Production Programme became visible; it is these insights which inform future improvements to similar programmes. Emanating from these findings, two overarching practice architectures (PA) were identified which restrained the Production Programme in the same manner that the banks of a river restrain a river, and yet simultaneously, are changed by the river over time. These are the PA of Methodology and Methods and the PA of Maturing Ecologies of Practices. The inferences drawn from the data were achieved through the use of deductive, inductive, and abductive reasoning. My claim to new knowledge is a lamination of a practical contribution on one side of the coin, and a theoretical contribution on the other side of the coin. The PA of Methodology and Methods provides a practical mechanism to create, deliver and assess IVET. This is done by explicating the three practice architectures which constitute the overarching PA of Methodology and Methods which are, the PA of Informality; the PA of Range, and the PA of Relationality. An IVET programme constitutes Ecologies of Practices. The theoretical conception of the overarching PA of Maturing Ecologies of Practices provides a conceptual tool which enables the transferring and scaling of IVET programmes. It does this by providing theoretical indicators to establish the ‘state’ of an IVET programme as it matures over time from a pioneer state to a settler state. An IVET educator can then work towards creating a PA which is conducive for a mature ecologies of practices to form; and the programme can then be transferred and/or taken to scale, if this is desirable in the particular context. The power of my claim to new knowledge does not lie on one side or the other of the coin, but in the lamination of the practical and theoretical contributions put to use in the service of IVET. This thesis concludes with a number of theoretical and practical recommendations which are loosely grouped according to ‘sayings/thinkings’, ‘doings’ and ‘relatings’ in deference to the value of TPA to this thesis. An urgency is conveyed in these recommendations as there is an immediate need to improve the livelihoods of ordinary South Africans. One of the ways of doing this is through informal ‘education for living well’ which contributes to a ‘world worth living in’. , Thesis (PhD) -- Faculty of Education, Education, 2023
- Full Text:
- Date Issued: 2023-03-29
- Authors: Ferguson, Robin Anne
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366189 , vital:65841 , DOI https://doi.org/10.21504/10962/366189
- Description: This thesis is a reflection of informal vocational education and training (IVET) practices conducted by the Researcher in the commercial fishing industry between 1995-2021. Fourteen interventions took place during this time which involved several hundred sea-going employees who are disadvantaged by low levels of literacies and low/no Internet Computer Technology connectivity. The Production Programme was chosen as the focus of study and draws upon the influence of the other thirteen programmes. The purpose of the Production Programme was to teach technical fish processing skills to the production management teams and factory hands who work in the factories on board the vessels. The programme ran for five years and evolved through three distinct generations. At the heart of this work lies the question: ‘What made these programmes successful?’ This is an intra-programmatic study and seeks to identify the pedagogical practices which promoted or confounded the efficacy of the Production Programme; and based upon this understanding how such programmes could be improved, transferred, and taken to scale. These questions are both descriptive and explorative in nature. IVET is regarded as training which takes place outside of the formal South African National Qualifications Framework. This work is relevant because approximately 80% of sea-going staff neither finish school, nor get the opportunity of Post School Education and Training by going to a university, a technical institution, or a community college. This statistic is reflected in the general population (Department of Higher Education and Training [DHET], 2022). There is a fine line between being employed and unemployed for people working at this level in the formal economy which makes this project relevant to youth or persons who are ‘not in employment, education or training’ too. This means that for most South African adults IVET presents a significant opportunity for post-school education. Therefore, it is important to answer the questions raised above to rapidly improve inclusion of the majority of South Africans into meaningful education which improves livelihoods. The Theory of Practice Architectures (TPA), from the collection of social-material practice theories, is the conceptual framework for this thesis. The smallest unit of analysis of TPA are practices which may be ‘sayings/thinkings’, ‘doings’, or ‘relatings’. These practices bundle together into practice arrangements and form practice architectures. The reason that TPA was chosen was that practices were the only data available as we (learners, managers, facilitators, and me) knew what we had said/thought or done, and we were aware of the relationships between us over the years as the fourteen interventions played out. Under conventional research circumstances data would be collected in real time, however in this project, most of the data is historical. In addition to the fundamental building blocks of TPA, the theory is embedded in a Theory of Education. There have also been contemporary enhancements to the TPA which were significant to this study, for example, the Ecologies of Practices, a Trellis of Practices which Support Professional Learning, Middle Leadership, Travelling Practices, and moves towards transformative or transgressive education using the TPA in IVET. This is empirical, qualitative research and an ethnographic case study was chosen as the research design which is a methodology particularly suited to answering both descriptive and explorative questions. Nine methods for data collection were used, namely an historical reflective narrative; two focused-group interviews; three individual interviews; four Whatsapp videos; one WhatsApp voice note; two mobisodes; ten questionnaires; 29 documents; and 16 photographs. Because this data was collected under Covid-19 pandemic conditions, two conceptions were employed to guide the generation of data under these uncertain and constrained conditions. These were firstly, the ‘methodology of chance’ which allowed for a ‘methodological agility’; and secondly, the idea of ‘information power’ which is helpful in deciding on how much data is enough. In order to be explicit concerning a key research activity, the approach and method used to review the literature is explicated. Key practices were identified in the data set and described; and then the data was analysed using heuristics provided by TPA theorists. Seven Tables of Invention were used to synthesise the data arising from these practices. An eighth Table of Invention was used to synthesise all the practices and practice arrangements characterised; and to indicate how these evolved over time and space. The data description and analysis is supported by eight Analytic Memos, a comprehensive Data Code Table and a hyperlink to a data repository which provides access to oral and video material. The findings distinguished five key practices and practice arrangements which were: Practices of the Creation of Courseware; Practices of Teaching and Learning; Practices of Assessment; Practices of Love; Practices of Management. The thesis title is reflective of the impact which love has upon the pedagogical process of IVET. Based upon the analysis and synthesis of the corpus of data, practices which either promoted or confounded the Production Programme became visible; it is these insights which inform future improvements to similar programmes. Emanating from these findings, two overarching practice architectures (PA) were identified which restrained the Production Programme in the same manner that the banks of a river restrain a river, and yet simultaneously, are changed by the river over time. These are the PA of Methodology and Methods and the PA of Maturing Ecologies of Practices. The inferences drawn from the data were achieved through the use of deductive, inductive, and abductive reasoning. My claim to new knowledge is a lamination of a practical contribution on one side of the coin, and a theoretical contribution on the other side of the coin. The PA of Methodology and Methods provides a practical mechanism to create, deliver and assess IVET. This is done by explicating the three practice architectures which constitute the overarching PA of Methodology and Methods which are, the PA of Informality; the PA of Range, and the PA of Relationality. An IVET programme constitutes Ecologies of Practices. The theoretical conception of the overarching PA of Maturing Ecologies of Practices provides a conceptual tool which enables the transferring and scaling of IVET programmes. It does this by providing theoretical indicators to establish the ‘state’ of an IVET programme as it matures over time from a pioneer state to a settler state. An IVET educator can then work towards creating a PA which is conducive for a mature ecologies of practices to form; and the programme can then be transferred and/or taken to scale, if this is desirable in the particular context. The power of my claim to new knowledge does not lie on one side or the other of the coin, but in the lamination of the practical and theoretical contributions put to use in the service of IVET. This thesis concludes with a number of theoretical and practical recommendations which are loosely grouped according to ‘sayings/thinkings’, ‘doings’ and ‘relatings’ in deference to the value of TPA to this thesis. An urgency is conveyed in these recommendations as there is an immediate need to improve the livelihoods of ordinary South Africans. One of the ways of doing this is through informal ‘education for living well’ which contributes to a ‘world worth living in’. , Thesis (PhD) -- Faculty of Education, Education, 2023
- Full Text:
- Date Issued: 2023-03-29
COVID19 and accountability in South Africa: legislation, ethics and disaster risk management
- Authors: Chapman, Emma Deidre
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419565 , vital:71655
- Description: Embargoed. Possible release in 2026 pending publication. , Thesis (MSC Pharm) -- Faculty of Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Chapman, Emma Deidre
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419565 , vital:71655
- Description: Embargoed. Possible release in 2026 pending publication. , Thesis (MSC Pharm) -- Faculty of Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-13
Examining the expenditures and retention of money of recreational fishing along the Wild Coast, South Africa
- Authors: Pyle, Michael Jonathan
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419673 , vital:71665
- Description: Developing countries and rural communities rely heavily on the ocean for food, transport, and the sustainability of their livelihoods. While the economics of small-scale fisheries in rural areas have received much attention, there is generally less information on the economic contributions from recreational fisheries in these areas. South Africa’s marine recreational fishery is large and contributes to a significant amount of economic activity. However, the retention of money from recreational fishing activities in local rural economies is unknown and thus the potential developmental benefits from this sector remain unquantified. This study examined the economic contributions from recreational fishing along the Wild Coast and retention of expenditures within the local economy. A total of 109 face-to-face economic surveys were administered during the peak recreational fishing season in December 2021. Based on the results, recreational fishing in the Wild Coast has the ability to generate R 415 446 098 in economic activity annually, however only 9.5% of this is retained within local coastal economies, which diminishes the economic contributions of the fishery to the Wild Coast region. Expenditures on items stemming from the informal collection and selling of bait and seafood, domestic work and guiding were the highest locally retained expenditures within the region. 98% of all bait and seafood was harvested and sold by local gillies, with 2% being bought through hotels (n=109). The total direct economic contribution in terms of informal harvesting was estimated at R 16 077 711 for 2021 (n= 9 601). The identification of these contributions can be used to provide recommendations for local economic development strategies which can support the recreational fishery while uplifting coastal communities that should be benefitting more from the activity. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Pyle, Michael Jonathan
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419673 , vital:71665
- Description: Developing countries and rural communities rely heavily on the ocean for food, transport, and the sustainability of their livelihoods. While the economics of small-scale fisheries in rural areas have received much attention, there is generally less information on the economic contributions from recreational fisheries in these areas. South Africa’s marine recreational fishery is large and contributes to a significant amount of economic activity. However, the retention of money from recreational fishing activities in local rural economies is unknown and thus the potential developmental benefits from this sector remain unquantified. This study examined the economic contributions from recreational fishing along the Wild Coast and retention of expenditures within the local economy. A total of 109 face-to-face economic surveys were administered during the peak recreational fishing season in December 2021. Based on the results, recreational fishing in the Wild Coast has the ability to generate R 415 446 098 in economic activity annually, however only 9.5% of this is retained within local coastal economies, which diminishes the economic contributions of the fishery to the Wild Coast region. Expenditures on items stemming from the informal collection and selling of bait and seafood, domestic work and guiding were the highest locally retained expenditures within the region. 98% of all bait and seafood was harvested and sold by local gillies, with 2% being bought through hotels (n=109). The total direct economic contribution in terms of informal harvesting was estimated at R 16 077 711 for 2021 (n= 9 601). The identification of these contributions can be used to provide recommendations for local economic development strategies which can support the recreational fishery while uplifting coastal communities that should be benefitting more from the activity. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2023
- Full Text:
- Date Issued: 2023-10-13
Application of in vitro release testing (IVRT) to assess “sameness”/differences of topical clotrimazole formulations
- Wellington, Hannah Margaret Mary
- Authors: Wellington, Hannah Margaret Mary
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419599 , vital:71658
- Description: Embargoed. Possible release date early 2025 pending publications. , Thesis (MSC Pharm) -- Faculty of Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Wellington, Hannah Margaret Mary
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419599 , vital:71658
- Description: Embargoed. Possible release date early 2025 pending publications. , Thesis (MSC Pharm) -- Faculty of Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-13
Identification of novel Arf1 GTPase inhibitors for cancer target validation
- Authors: Mqwathi, Nomxolisi Vuyokasi
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424666 , vital:72173
- Description: The key regulators of both anterograde and retrograde vesicular traffic, adenosine diphosphate-ribosylation factors (Arfs), also coordinate various signalling pathways and regulate cellular processes required for cell survival and function. In addition to its role in mediating secretory trafficking in the Golgi apparatus, the involvement of Arf1 in signalling pathways that contribute to the formation and progression of cancer has become apparent, and the overexpression and deregulation of Arf1 activity has been associated with cancer cell invasion, proliferation and metastasis. As with other small GTPases, Arf1 must cycle back and forth between an inactive (GDP-bound) and active (GTP-bound) conformation to carry out its function. However, the cycle of Arf1 inactivation and activation is controlled by Arf GTPase activating proteins (Arf-GAPs) that stimulate Arf1 to hydrolyse the bound GTP to GDP and Arf guanine nucleotide exchange factors (Arf-GEFs) that facilitate GDP for GTP exchange on Arf1, respectively. The identification of Arf1 inhibitors that indirectly disrupt Arf1 function by blocking its interaction with Arf-GAPs or Arf-GEFs has generated interest in their use as possible anti-cancer agents. The suppression of Arf1 activation (by targeting Arf-GEFs) has been investigated as a potential cancer therapeutic target and resulted in inhibitor compounds that have micromolar-range activity against cancer cells and targets and promising results in mouse models, but experience problems with bioavailability when used in vivo. This motivates the search for novel Arf1 inhibitors for validation purposes to question whether Arf1 is a viable target for cancer therapy. The purpose of the study was to employ a recently developed colourimetric screening assay to identify inhibitors of Arf1 activation (Arf-GEF inhibitors) and deactivation (Arf-GAP inhibitors), with a focus on evaluating the potential of Arf1 deactivation as an entirely novel anti-cancer target. The proteins required for the assay (Arf1, Arf-GEF and -GAP domains and a reporter protein, GST-GGA3) were expressed in E. coli. and purified using affinity chromatography. The assay could detect the activation of Arf1 by the catalytic Sec7 domain of the three Arf-GEFs chosen for this study, but reproducibility was compromised by the occasional spontaneous activation of Arf1 in the absence of the Arf-GEFs. By contrast, the assay could reproducibly detect Arf1 deactivation by an Arf-GAP domain (Arf-GAP1GAP) and was subsequently used to screen a library of α-helix mimetics. Thirteen hit compounds with IC50 values ranging from 0.53 to 20.95 μM were found to inhibit Arf-GAP1GAP-mediated stimulation of GTP hydrolysis by Arf1-GTP in this assay format, however, they did not effectively suppress the proliferation of three tested cell lines (HeLa, MCF-7 and MCF-12A). Interestingly, the results obtained from fluorescence microscopy studies suggested that the compounds disrupt Golgi structure and Arf1 localisation, presumably by keeping Arf1 in its active conformation by blocking Arf-GAP1 function. This suggests that the compounds affect Arf1 function in cells, and may be used to explore the feasibility of targeting Arf1 deactivation for anti-cancer purposes in a wider range of cell lines and experiments. It has been reported that Arf-GAP1 inhibition is associated with the suppression of cell migration, and the potential of the compounds as metastasis inhibitors may also be explored. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Mqwathi, Nomxolisi Vuyokasi
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424666 , vital:72173
- Description: The key regulators of both anterograde and retrograde vesicular traffic, adenosine diphosphate-ribosylation factors (Arfs), also coordinate various signalling pathways and regulate cellular processes required for cell survival and function. In addition to its role in mediating secretory trafficking in the Golgi apparatus, the involvement of Arf1 in signalling pathways that contribute to the formation and progression of cancer has become apparent, and the overexpression and deregulation of Arf1 activity has been associated with cancer cell invasion, proliferation and metastasis. As with other small GTPases, Arf1 must cycle back and forth between an inactive (GDP-bound) and active (GTP-bound) conformation to carry out its function. However, the cycle of Arf1 inactivation and activation is controlled by Arf GTPase activating proteins (Arf-GAPs) that stimulate Arf1 to hydrolyse the bound GTP to GDP and Arf guanine nucleotide exchange factors (Arf-GEFs) that facilitate GDP for GTP exchange on Arf1, respectively. The identification of Arf1 inhibitors that indirectly disrupt Arf1 function by blocking its interaction with Arf-GAPs or Arf-GEFs has generated interest in their use as possible anti-cancer agents. The suppression of Arf1 activation (by targeting Arf-GEFs) has been investigated as a potential cancer therapeutic target and resulted in inhibitor compounds that have micromolar-range activity against cancer cells and targets and promising results in mouse models, but experience problems with bioavailability when used in vivo. This motivates the search for novel Arf1 inhibitors for validation purposes to question whether Arf1 is a viable target for cancer therapy. The purpose of the study was to employ a recently developed colourimetric screening assay to identify inhibitors of Arf1 activation (Arf-GEF inhibitors) and deactivation (Arf-GAP inhibitors), with a focus on evaluating the potential of Arf1 deactivation as an entirely novel anti-cancer target. The proteins required for the assay (Arf1, Arf-GEF and -GAP domains and a reporter protein, GST-GGA3) were expressed in E. coli. and purified using affinity chromatography. The assay could detect the activation of Arf1 by the catalytic Sec7 domain of the three Arf-GEFs chosen for this study, but reproducibility was compromised by the occasional spontaneous activation of Arf1 in the absence of the Arf-GEFs. By contrast, the assay could reproducibly detect Arf1 deactivation by an Arf-GAP domain (Arf-GAP1GAP) and was subsequently used to screen a library of α-helix mimetics. Thirteen hit compounds with IC50 values ranging from 0.53 to 20.95 μM were found to inhibit Arf-GAP1GAP-mediated stimulation of GTP hydrolysis by Arf1-GTP in this assay format, however, they did not effectively suppress the proliferation of three tested cell lines (HeLa, MCF-7 and MCF-12A). Interestingly, the results obtained from fluorescence microscopy studies suggested that the compounds disrupt Golgi structure and Arf1 localisation, presumably by keeping Arf1 in its active conformation by blocking Arf-GAP1 function. This suggests that the compounds affect Arf1 function in cells, and may be used to explore the feasibility of targeting Arf1 deactivation for anti-cancer purposes in a wider range of cell lines and experiments. It has been reported that Arf-GAP1 inhibition is associated with the suppression of cell migration, and the potential of the compounds as metastasis inhibitors may also be explored. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
Investigation of brewery waste grains and microbial fuel cells as value-additive technologies improving solvent production yields in Clostridium acetobutylicum (ATCC 824) fermentation
- Authors: Du Toit, Ryan Guillaume
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424643 , vital:72171
- Description: The production of the solvent compounds acetone, ethanol and butanol through fermentation of organic feedstocks using Clostridia species could be a promising route for biofuel production. However, the cost of raw materials, low yields and the complexity of anaerobic fermentation continue to hinder this means of generating these compounds. The research presented in this Thesis investigated low-cost interventions that could decrease the costs of production and to direct the synthesis of fuel compounds using microbial fuel cells. Low-cost anaerobic chambers were designed and constructed for the propagation and manipulation of Clostridium acetobutylicum, selected as a low-risk microbial catalyst. Fermentation was monitored using in situ pH measurements and a combination of turbidity measurements, nutrient assays (especially total carbohydrates) and HPLC-RI detection as a means of monitoring the consumption of nutrients (glucose), production of precursor compounds (butyric acid) and the formation of solvent molecules (acetone/ethanol and butanol) during fermentation by this organism. Brewer’s spent grains were tested as a sustainable and low-cost feedstock for solvent production, comparing the effects of sterilising before fermentation, or allowing resident microflora to remain during Clostridium-catalysed solvent production. Sterilised spent grains significantly improved the production of solvent molecules (e.g. 12.97 ± 0.38 g/L of butanol yielded, compared to 0.40 ± 0.33 g/L for defined media sampled during the solventogenic phase); compared to these, the use of non-sterilised brewer’s grain decreased both the reproducibility and yields of fermentation (8.66 ± 1.6 g/L of butanol). Microbial fuel cells were studied as a possible means of altering electron transfer to/from electrode-attached Clostridia to control the metabolic shift in bacteria from acidogenesis to solventogenesis. The base line MFC (11.00 ± 4.69 g/L) fermentation experiment did produce higher acetone/ethanol than the baseline batch experiment MB (5.47 ± 4.48 g/L), indicating an improvement to solvent production in C. acetobutylicum (ATCC 824) in a MFC fermentation. In this study, MFC-1 demonstrated remarkable superiority over MB in terms of butyric acid production, yielding significantly higher concentrations while also improving acetone and ethanol production. However, the enhanced butyric acid production did not correspond to significantly increased butanol yields when compared to batch fermentation of chemically defined media. These findings highlight the potential of MFC-1 as an efficient approach for enhancing the fermentative production of valuable compounds, with a particular focus on butyric acid and acetone/ethanol. , Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Du Toit, Ryan Guillaume
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424643 , vital:72171
- Description: The production of the solvent compounds acetone, ethanol and butanol through fermentation of organic feedstocks using Clostridia species could be a promising route for biofuel production. However, the cost of raw materials, low yields and the complexity of anaerobic fermentation continue to hinder this means of generating these compounds. The research presented in this Thesis investigated low-cost interventions that could decrease the costs of production and to direct the synthesis of fuel compounds using microbial fuel cells. Low-cost anaerobic chambers were designed and constructed for the propagation and manipulation of Clostridium acetobutylicum, selected as a low-risk microbial catalyst. Fermentation was monitored using in situ pH measurements and a combination of turbidity measurements, nutrient assays (especially total carbohydrates) and HPLC-RI detection as a means of monitoring the consumption of nutrients (glucose), production of precursor compounds (butyric acid) and the formation of solvent molecules (acetone/ethanol and butanol) during fermentation by this organism. Brewer’s spent grains were tested as a sustainable and low-cost feedstock for solvent production, comparing the effects of sterilising before fermentation, or allowing resident microflora to remain during Clostridium-catalysed solvent production. Sterilised spent grains significantly improved the production of solvent molecules (e.g. 12.97 ± 0.38 g/L of butanol yielded, compared to 0.40 ± 0.33 g/L for defined media sampled during the solventogenic phase); compared to these, the use of non-sterilised brewer’s grain decreased both the reproducibility and yields of fermentation (8.66 ± 1.6 g/L of butanol). Microbial fuel cells were studied as a possible means of altering electron transfer to/from electrode-attached Clostridia to control the metabolic shift in bacteria from acidogenesis to solventogenesis. The base line MFC (11.00 ± 4.69 g/L) fermentation experiment did produce higher acetone/ethanol than the baseline batch experiment MB (5.47 ± 4.48 g/L), indicating an improvement to solvent production in C. acetobutylicum (ATCC 824) in a MFC fermentation. In this study, MFC-1 demonstrated remarkable superiority over MB in terms of butyric acid production, yielding significantly higher concentrations while also improving acetone and ethanol production. However, the enhanced butyric acid production did not correspond to significantly increased butanol yields when compared to batch fermentation of chemically defined media. These findings highlight the potential of MFC-1 as an efficient approach for enhancing the fermentative production of valuable compounds, with a particular focus on butyric acid and acetone/ethanol. , Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2023
- Full Text:
- Date Issued: 2023-10-13
Comparison of the metabolic physiology of exploited and unexploited populations of red roman (Chrysoblephus laticeps) along the south coast of South Africa
- Authors: Nabani, Xolani Prince
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424358 , vital:72146
- Description: Anthropogenic-induced climate change and exploitation pose threat to many marine fishes on which a vast majority of people around the world depend. Rapid changes in sea surface temperature have a direct impact on the physiology of ectothermic organisms such as fish, potentially resulting in changes to population distribution, abundance, and demographics. In the face of climate change, the impacts of increasing temperature variability on fish populations may be exacerbated by exploitation. Understanding how the resilience of exploited populations is affected by climate change is critical to predict how fishes will respond in the future. This study aimed to augment our knowledge on the impact of exploitation and thermal variability on fishes by comparing the thermal physiology of an exploited and unexploited population of the resident, reef-dwelling, Chrysoblephus laticeps. Twenty live fish were collected from the exploited, Cape St Francis and 18 fish from the unexploited, Goukamma Marine Protected Area and transported to the laboratory. The metabolic performance, in terms of standard metabolic rate (SMR), maximum metabolic rate (MMR) and aerobic scope (AS) of individual C. laticeps were estimated repeatedly at 10 ℃, 16 °C and 21 °C. Linear mixed effects models were used to examine the relationship between temperature, population, and metabolic rate and a ‘cvequality’ test analysis was used to compare the variance structure of the metabolic rate regression model for each population. Overall, the findings of this study show that Chrysoblephus laticeps from the unexploited population maintains a significantly higher aerobic scope (AS) across all temperature treatments (10, 16 and 21 ℃) when compared with those from the exploited population. In addition, the maximum metabolic rate (MMR) of individuals from the unexploited population was significantly higher than that of individuals from the exploited population, but there was no evidence to suggest that variability was significantly different between the populations. On the other hand, the individuals from an exploited population had a significantly higher standard metabolic rate (SMR) at high temperatures of 21 ℃, while the unexploited population had a low SMR at these high temperatures, but a high SMR at 10 ℃. Despite these differences there was no significant variation in the SMR between the two populations. The findings of this study confirm previous work on different exploited and unexploited populations of C. laticeps and together these findings suggest that hook and line exploitation lead to reduced physiological phenotypic diversity and reduced physiological performance in exploited fish populations. These findings emphasise the importance of incorporating the iii physiological information to develop viable fisheries management tools in the context of climate change. This study also highlights the effectiveness of MPAs in conserving highperformance physiological phenotypes to maintain phenotypic diversity in fish populations. Future research should aim to evaluate the efficacy of existing MPAs in preserving the physiological diversity of important hook and line fisheries species, while fisheries managers should consider augmenting their approaches through the incorporation of well-designed MPA’s to promote physiological diversity. This will be critical to advance the development of sustainable management practices, not only in a South African context but globally, where oceanic and coastal environmental conditions are expected to rapidly change in the future. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Nabani, Xolani Prince
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424358 , vital:72146
- Description: Anthropogenic-induced climate change and exploitation pose threat to many marine fishes on which a vast majority of people around the world depend. Rapid changes in sea surface temperature have a direct impact on the physiology of ectothermic organisms such as fish, potentially resulting in changes to population distribution, abundance, and demographics. In the face of climate change, the impacts of increasing temperature variability on fish populations may be exacerbated by exploitation. Understanding how the resilience of exploited populations is affected by climate change is critical to predict how fishes will respond in the future. This study aimed to augment our knowledge on the impact of exploitation and thermal variability on fishes by comparing the thermal physiology of an exploited and unexploited population of the resident, reef-dwelling, Chrysoblephus laticeps. Twenty live fish were collected from the exploited, Cape St Francis and 18 fish from the unexploited, Goukamma Marine Protected Area and transported to the laboratory. The metabolic performance, in terms of standard metabolic rate (SMR), maximum metabolic rate (MMR) and aerobic scope (AS) of individual C. laticeps were estimated repeatedly at 10 ℃, 16 °C and 21 °C. Linear mixed effects models were used to examine the relationship between temperature, population, and metabolic rate and a ‘cvequality’ test analysis was used to compare the variance structure of the metabolic rate regression model for each population. Overall, the findings of this study show that Chrysoblephus laticeps from the unexploited population maintains a significantly higher aerobic scope (AS) across all temperature treatments (10, 16 and 21 ℃) when compared with those from the exploited population. In addition, the maximum metabolic rate (MMR) of individuals from the unexploited population was significantly higher than that of individuals from the exploited population, but there was no evidence to suggest that variability was significantly different between the populations. On the other hand, the individuals from an exploited population had a significantly higher standard metabolic rate (SMR) at high temperatures of 21 ℃, while the unexploited population had a low SMR at these high temperatures, but a high SMR at 10 ℃. Despite these differences there was no significant variation in the SMR between the two populations. The findings of this study confirm previous work on different exploited and unexploited populations of C. laticeps and together these findings suggest that hook and line exploitation lead to reduced physiological phenotypic diversity and reduced physiological performance in exploited fish populations. These findings emphasise the importance of incorporating the iii physiological information to develop viable fisheries management tools in the context of climate change. This study also highlights the effectiveness of MPAs in conserving highperformance physiological phenotypes to maintain phenotypic diversity in fish populations. Future research should aim to evaluate the efficacy of existing MPAs in preserving the physiological diversity of important hook and line fisheries species, while fisheries managers should consider augmenting their approaches through the incorporation of well-designed MPA’s to promote physiological diversity. This will be critical to advance the development of sustainable management practices, not only in a South African context but globally, where oceanic and coastal environmental conditions are expected to rapidly change in the future. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
The effect of piospheres on the ecology of insectivorous birds and their arthropod prey
- Authors: Balmer, Natasha Louise
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424380 , vital:72148
- Description: Desertification is the degradation of arid ecosystems that result in the loss of biodiversity. Piospheres are areas of local degradation around a central point due to overgrazing and increased herbivore presence. There is a paucity of information regarding the effect of localised degradation on arthropods and insectivorous birds. Both of these organisms play crucial roles in ecosystem functioning and stability and can be used as models to study ecosystem functioning. I investigated the effect of piospheres on arthropods and birds in the Eastern Cape province of South Africa. I found that the abundance and diversity of arthropods were significantly reduced inside the piospheres due to the lack of vegetation. Termites were a group specifically negatively impacted by piospheres, with a significant reduction in their presence inside the piosphere. The family composition of arthropods also changed inside and outside the piospheres, with Caelifera, Diptera and Formicidae being the most dominant groups. The diversity of birds was also significantly reduced due to the degradation inside the piospheres. Looking at insectivorous birds, I found that the reduction in both vegetation and arthropod prey availability resulted in non-random avoidance of piospheres. This shows that piospheres negatively impact both arthropods and birds. The results from my study are supported by other literature studying the effects of habitat degradation associated with desertification. Due to the similarities of degradation between piospheres and desertification I make the argument that piospheres can be studied as localised models of desertification. The decrease in vegetation and arthropod abundance and diversity was found to further impact the feeding success of insectivorous birds. Using piospheres as a model for desertification, I found that the foraging effort of birds is significantly reduced within a degraded area due to the lack of vegetation providing safety to arthropod prey species. In addition to this, the foraging efficiency of insectivorous birds is significantly reduced inside the piospheres due to the decreased arthropod abundance and diversity. This shows that inside the piospheres birds spend less time searching for insects and have fewer successful feeds. This has implications for desertification of arid environments where birds face hyperthermia. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Balmer, Natasha Louise
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424380 , vital:72148
- Description: Desertification is the degradation of arid ecosystems that result in the loss of biodiversity. Piospheres are areas of local degradation around a central point due to overgrazing and increased herbivore presence. There is a paucity of information regarding the effect of localised degradation on arthropods and insectivorous birds. Both of these organisms play crucial roles in ecosystem functioning and stability and can be used as models to study ecosystem functioning. I investigated the effect of piospheres on arthropods and birds in the Eastern Cape province of South Africa. I found that the abundance and diversity of arthropods were significantly reduced inside the piospheres due to the lack of vegetation. Termites were a group specifically negatively impacted by piospheres, with a significant reduction in their presence inside the piosphere. The family composition of arthropods also changed inside and outside the piospheres, with Caelifera, Diptera and Formicidae being the most dominant groups. The diversity of birds was also significantly reduced due to the degradation inside the piospheres. Looking at insectivorous birds, I found that the reduction in both vegetation and arthropod prey availability resulted in non-random avoidance of piospheres. This shows that piospheres negatively impact both arthropods and birds. The results from my study are supported by other literature studying the effects of habitat degradation associated with desertification. Due to the similarities of degradation between piospheres and desertification I make the argument that piospheres can be studied as localised models of desertification. The decrease in vegetation and arthropod abundance and diversity was found to further impact the feeding success of insectivorous birds. Using piospheres as a model for desertification, I found that the foraging effort of birds is significantly reduced within a degraded area due to the lack of vegetation providing safety to arthropod prey species. In addition to this, the foraging efficiency of insectivorous birds is significantly reduced inside the piospheres due to the decreased arthropod abundance and diversity. This shows that inside the piospheres birds spend less time searching for insects and have fewer successful feeds. This has implications for desertification of arid environments where birds face hyperthermia. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
Spatial analysis of littoral and demersal fish assemblages within the Knysna Estuary system
- Authors: Meiklejohn, Andrew Keith
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424334 , vital:72144
- Description: The Knysna Estuary is a unique system as it is the only “estuarine bay” system in the warm-temperate region of South Africa and is the largest estuary system on the southern coastline of South Africa. The Knysna Estuary has been identified as the estuary with the highest conversation priority in South Africa. The volume of research undertaken on the Knysna Estuary has led to it being rated “excellent” in terms of research productivity. However, despite this, surprisingly little work has been undertaken and published around the dynamics of fish assemblages occurring in the system, with little to no research assessing the demersal fish assemblage. The last widespread fish sampling effort that has been published was conducted in 1994, highlighting the need for an updated fish assessment with a focused sampling effort targeting both the littoral and demersal fish populations. The identification of key habitats for estuarine fish assemblages is essential for addressing estuarine conservation needs. Despite the importance of spatial data in addressing conservation planning, few estuarine studies have used spatial analyses in Geographic Information Systems (GIS) to identify conservation priority areas. Such information is critical for effective estuarine management plans. The aim of this project was to identify juvenile fish density hotspots to inform future systematic conservation planning. This study made use of two methods of sampling, seine netting to target the littoral fish assemblage and beam trawling to target demersal fish species. Two dedicated sampling trips for each sampling method were undertaken in June 2021 and March 2022 for Seine net sampling and November 2021 and March 2022 for Beam trawl sampling. Fish were identified to species level, measured (mm TL) and categorised into life history stages (i.e. settlement stage, juvenile and adult) and thereafter assigned into their various estuarine association guilds. A total of 47 species were recorded, with 42 species were caught in the seine net sampling and 24 species in the beam trawl sampling. The results from this study showed the vast extent of marine dominance in the Knysna Estuary, with marine estuarine-opportunist (MEO) species dominating catches (richness) from both sampling methods. The spatial analysis highlighted the importance of the lower “marine bay” region of the system, with the majority of estuarine guilds showing a high abundance in this region. Key fishery species and dominant fish species were identified during this study, the dominant species during the sampling effort were identified as ecologically important fish species and were dominated by adult specimens. The key fishery species sampled during this study were dominated by juvenile specimens. This highlights the role of the Knysna Estuary as a nursery area for juvenile fishery species and the contribution of the estuary to the estuarine and adjacent coastal fisheries. Key hotspots were identified for fishery species, these being the “Ashmead Channel” in the marine bay region and the “Belvidere” section of the lagoon region. Ashmead channel is sheltered backwater area while the Belvidere section is some distance from the main river channel, reducing the anthropogenic impact on these areas. The low anthropogenic utilization of these areas along with weaker water current in these regions was linked to the usage of these region by key fishery species. These areas were highlighted as important conservation hotspots with both currently not adequately protected under the current habitat sensitivity management model. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Meiklejohn, Andrew Keith
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424334 , vital:72144
- Description: The Knysna Estuary is a unique system as it is the only “estuarine bay” system in the warm-temperate region of South Africa and is the largest estuary system on the southern coastline of South Africa. The Knysna Estuary has been identified as the estuary with the highest conversation priority in South Africa. The volume of research undertaken on the Knysna Estuary has led to it being rated “excellent” in terms of research productivity. However, despite this, surprisingly little work has been undertaken and published around the dynamics of fish assemblages occurring in the system, with little to no research assessing the demersal fish assemblage. The last widespread fish sampling effort that has been published was conducted in 1994, highlighting the need for an updated fish assessment with a focused sampling effort targeting both the littoral and demersal fish populations. The identification of key habitats for estuarine fish assemblages is essential for addressing estuarine conservation needs. Despite the importance of spatial data in addressing conservation planning, few estuarine studies have used spatial analyses in Geographic Information Systems (GIS) to identify conservation priority areas. Such information is critical for effective estuarine management plans. The aim of this project was to identify juvenile fish density hotspots to inform future systematic conservation planning. This study made use of two methods of sampling, seine netting to target the littoral fish assemblage and beam trawling to target demersal fish species. Two dedicated sampling trips for each sampling method were undertaken in June 2021 and March 2022 for Seine net sampling and November 2021 and March 2022 for Beam trawl sampling. Fish were identified to species level, measured (mm TL) and categorised into life history stages (i.e. settlement stage, juvenile and adult) and thereafter assigned into their various estuarine association guilds. A total of 47 species were recorded, with 42 species were caught in the seine net sampling and 24 species in the beam trawl sampling. The results from this study showed the vast extent of marine dominance in the Knysna Estuary, with marine estuarine-opportunist (MEO) species dominating catches (richness) from both sampling methods. The spatial analysis highlighted the importance of the lower “marine bay” region of the system, with the majority of estuarine guilds showing a high abundance in this region. Key fishery species and dominant fish species were identified during this study, the dominant species during the sampling effort were identified as ecologically important fish species and were dominated by adult specimens. The key fishery species sampled during this study were dominated by juvenile specimens. This highlights the role of the Knysna Estuary as a nursery area for juvenile fishery species and the contribution of the estuary to the estuarine and adjacent coastal fisheries. Key hotspots were identified for fishery species, these being the “Ashmead Channel” in the marine bay region and the “Belvidere” section of the lagoon region. Ashmead channel is sheltered backwater area while the Belvidere section is some distance from the main river channel, reducing the anthropogenic impact on these areas. The low anthropogenic utilization of these areas along with weaker water current in these regions was linked to the usage of these region by key fishery species. These areas were highlighted as important conservation hotspots with both currently not adequately protected under the current habitat sensitivity management model. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
Phylogeography of two small owl species in South Africa: population genetics and phenotypic variation in the African Barred Owlet (Glaucidium capense) and the African Scops Owl (Otus senegalensis)
- Authors: Balmer, Jonathan Peter
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424369 , vital:72147
- Description: Embargoed. Expected release date in 2025. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Balmer, Jonathan Peter
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424369 , vital:72147
- Description: Embargoed. Expected release date in 2025. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
Enteric microbial responses to host hyperthermia in southern African insectivorous bats: a test of thermal co-adaptation
- Authors: Hunter, Amy Alison
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424391 , vital:72149
- Description: Embargoed. Expected release date 2025. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Hunter, Amy Alison
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424391 , vital:72149
- Description: Embargoed. Expected release date 2025. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
Exploring how Grade 11 Chemistry teachers mediate learning of the topic redox reactions in their classrooms in Namibia
- Iindombo, Junilla Inamudhimbwa
- Authors: Iindombo, Junilla Inamudhimbwa
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424030 , vital:72117
- Description: The Namibian Chemistry ordinary level syllabus requires learners to study the topic of redox reactions. This topic has proven to be one of the most difficult for Namibian learners as reflected by their poor responses to questions in the Grade 11 and 12 Namibian Senior Secondary Certificate ‘O’ examinations. Teaching abstract concepts such as redox reactions requires higher cognitive thinking skills and thus presents a challenge. Against this background, this study sought to explore how teachers mediate learning of redox reactions in their classrooms. The focus was on conceptual understanding through linking content to the context of the learners. The study was underpinned by an interpretivist paradigm, within which a qualitative case study approach was adopted. Two Grade 11 Chemistry teachers from the Ohangwena and Oshana regions in Namibia were the research participants. I used semi-structured interviews, lesson observations and stimulated recall interviews to collect data. I used Shulman’s Pedagogical Content Knowledge as a theoretical framework in this study and the data sets were analysed using the Topic-Specific Pedagogical Content Knowledge components. Qualitative data were analysed inductively-deductively. The study’s findings revealed that teachers used various mediation tools such as analogies and prior knowledge. The results further illuminated that teachers should develop strong subject content knowledge and pedagogical content knowledge to have the best strategies in place to mediate learning of this topic. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Iindombo, Junilla Inamudhimbwa
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424030 , vital:72117
- Description: The Namibian Chemistry ordinary level syllabus requires learners to study the topic of redox reactions. This topic has proven to be one of the most difficult for Namibian learners as reflected by their poor responses to questions in the Grade 11 and 12 Namibian Senior Secondary Certificate ‘O’ examinations. Teaching abstract concepts such as redox reactions requires higher cognitive thinking skills and thus presents a challenge. Against this background, this study sought to explore how teachers mediate learning of redox reactions in their classrooms. The focus was on conceptual understanding through linking content to the context of the learners. The study was underpinned by an interpretivist paradigm, within which a qualitative case study approach was adopted. Two Grade 11 Chemistry teachers from the Ohangwena and Oshana regions in Namibia were the research participants. I used semi-structured interviews, lesson observations and stimulated recall interviews to collect data. I used Shulman’s Pedagogical Content Knowledge as a theoretical framework in this study and the data sets were analysed using the Topic-Specific Pedagogical Content Knowledge components. Qualitative data were analysed inductively-deductively. The study’s findings revealed that teachers used various mediation tools such as analogies and prior knowledge. The results further illuminated that teachers should develop strong subject content knowledge and pedagogical content knowledge to have the best strategies in place to mediate learning of this topic. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10-13
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
Stimulating continuous professional development and teacher leadership in a rural Namibian school: a participatory action research
- Authors: Mario, Kangende Mebin
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424075 , vital:72121
- Description: Namibia values democratic and quality education. One way to improve quality education is by allowing teachers autonomy and offering continuous professional development (CPD) to teachers. Historically, the CPD programmes on offer in Namibia were centralised and generic, using a ‘one-size-fits-all’ approach offered as mini workshops to train teachers. In 2012, a decentralised method of school-based CPD program was initiated in schools, to give opportunities to schools to identify, plan, implement and evaluate their own professional needs. However, a recent study indicated that these initiatives have failed due to poor leadership, a lack of training and support as well as limited knowledge of principals in running CPD initiatives. Against this backdrop, my study aimed at engaging in a participatory action research process with teachers and SMT members in a rural combined school in the Kavango West region to stimulate the failed school-based CPD program and develop teacher leadership. My study therefore aligned with the international recommendations that school-based CPD be built around the notions of distributed leadership and teacher leadership (Smulyan, 2016; Hunzicker, 2018). The three-step model of change and action research developed by Kurt Lewin served as the underpinning theory for this study. The study was situated within a critical paradigm and driven by the question: “Does the involvement in participatory action research process stimulate a school-based CPD programme and develop teacher leadership?” The study involved two phases. The contextual profiling stage generated data through the analysis of documents, focus group interviews, and observation. Phase 2 engaged the participant in participatory action research to stimulate school-based CPD and develop teacher leadership. Thematic analysis supported by both inductive and deductive methods was used to analyse the data. The findings from phase one indicated that CPD was interpreted differently by the participants and confirmed that there was no CPD program in the school. Using Grant's (2017) model of teacher leadership, the findings further revealed that although teacher leadership was practised in all four zones, it was strongest in the classroom and initiated through delegated practices. Using Angelle and Dehart (2010), constraining forces included negative teachers’ attitudes, limited knowledge, skills, and confidence as well as a school culture of distrust. Phase 2 revealed that participatory action research can be a useful stimulus for school-based CPD. A tangible output from the PAR sessions was a template for the internal policy for school-based continuous teacher development. In addition, the findings from the sessions indicated the significance of supportive leadership to ensure the efficacy of school-based CPD and teacher leadership. , Thesis (MEd) -- Faculty of Education, Primary and Early Childhood Education, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Mario, Kangende Mebin
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424075 , vital:72121
- Description: Namibia values democratic and quality education. One way to improve quality education is by allowing teachers autonomy and offering continuous professional development (CPD) to teachers. Historically, the CPD programmes on offer in Namibia were centralised and generic, using a ‘one-size-fits-all’ approach offered as mini workshops to train teachers. In 2012, a decentralised method of school-based CPD program was initiated in schools, to give opportunities to schools to identify, plan, implement and evaluate their own professional needs. However, a recent study indicated that these initiatives have failed due to poor leadership, a lack of training and support as well as limited knowledge of principals in running CPD initiatives. Against this backdrop, my study aimed at engaging in a participatory action research process with teachers and SMT members in a rural combined school in the Kavango West region to stimulate the failed school-based CPD program and develop teacher leadership. My study therefore aligned with the international recommendations that school-based CPD be built around the notions of distributed leadership and teacher leadership (Smulyan, 2016; Hunzicker, 2018). The three-step model of change and action research developed by Kurt Lewin served as the underpinning theory for this study. The study was situated within a critical paradigm and driven by the question: “Does the involvement in participatory action research process stimulate a school-based CPD programme and develop teacher leadership?” The study involved two phases. The contextual profiling stage generated data through the analysis of documents, focus group interviews, and observation. Phase 2 engaged the participant in participatory action research to stimulate school-based CPD and develop teacher leadership. Thematic analysis supported by both inductive and deductive methods was used to analyse the data. The findings from phase one indicated that CPD was interpreted differently by the participants and confirmed that there was no CPD program in the school. Using Grant's (2017) model of teacher leadership, the findings further revealed that although teacher leadership was practised in all four zones, it was strongest in the classroom and initiated through delegated practices. Using Angelle and Dehart (2010), constraining forces included negative teachers’ attitudes, limited knowledge, skills, and confidence as well as a school culture of distrust. Phase 2 revealed that participatory action research can be a useful stimulus for school-based CPD. A tangible output from the PAR sessions was a template for the internal policy for school-based continuous teacher development. In addition, the findings from the sessions indicated the significance of supportive leadership to ensure the efficacy of school-based CPD and teacher leadership. , Thesis (MEd) -- Faculty of Education, Primary and Early Childhood Education, 2023
- Full Text:
- Date Issued: 2023-10-13
Mineral paragenesis of olmiite/poldevaartite and rhodochrosite/shigaite occurrences in the Kalahari Manganese Field, and their relation to the formation of high-grade manganese ore of Nchwaning II mine, Black Rock, South Africa
- Authors: Opperman, Alicia
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422448 , vital:71943
- Description: Access restricted. Access embargoed until 2025. , Thesis (MSc) -- Faculty of Science, Geology, 2023
- Full Text:
- Date Issued: 2023-03-29
- Authors: Opperman, Alicia
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422448 , vital:71943
- Description: Access restricted. Access embargoed until 2025. , Thesis (MSc) -- Faculty of Science, Geology, 2023
- Full Text:
- Date Issued: 2023-03-29
Factors influencing the number of non-timber forest product species used at the individual, household and village levels in Vhembe, Limpopo Province, South Africa
- Authors: Mulaudzi, Takalani Rachel
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422481 , vital:71946
- Description: Non-Timber Forest Products (NTFPs) are wild biological resources obtained from natural landscapes, agricultural systems, and rural and urban regions for a variety of uses. NTFPs contribute significantly to livelihoods and living standards by offering a variety of socioeconomic benefits such as food, health, income generation, and safety nets. These multiple benefits are provided by a wide diversity of plant, animal and fungal species in different settings. However, the precise number of NTFP species used depends on the scale of assessment, namely use by individuals, by households and by villages. Consequently, it is difficult to compare numbers of species used between studies because of the differing scales. As a result, the objective of this study was to determine the number of NTFP species used at three different scales and how each is correlated with appropriate scale-dependent contextual variables. This objective was met by sampling individuals and whole households in five villages in the Vhembe District in Limpopo Province, South Africa. Twenty households were randomly selected in each village, providing a total sample of 100 households and 179 individuals in those households. In each household, every adult member was interviewed individually about the NTFPs that they used or knew. The major questions covered the NTFP species used, the respondents' socioeconomic level, the NTFP species used previously, and if the number of NTFP species are changing in the landscape. Data were reported per individual as well as per household and per village. The household level was derived by adding the responses of all the adults in each household but excluding duplicates. The same approach was used at the village scale, namely, the data across the 20 households were pooled, and duplicates were omitted. Patterns of NTFP use were examined by type of NTFP, and analysis using standard statistical tests, along with a Principal Components Analysis and a multivariate Detrended Correspondence Analysis of the NTFP species composition across villages. A total of 275 species of NTFPs were mentioned across the entire sample, including 81 species of firewood, 48 species of edible insects, 43 species of wild vegetables, 40 species of edible fruits, 38 species of wood utensils, 28 species of medicinal plants, 23 species of thatch grass, 19 species of poles, 19 species of wood for carvings, nine species of reeds, eight species of mushroom, and eight species of fodder. Of these species, some species had more than one use. Approximately 90% of the species used by the respondents were native species. Wild vegetables (e.g., Corchorus olitorius, Amaranthus capensis, Bidens pilosa), firewood (e.g., Colophospermum mopane, Parinari curatellifolia, Combretum hereroense), wild fruit (e.g., Landolphia kirkii, Vangueria infausta), and edible insects (e.g., Imbrasia belina, Macrotermes michaelseni, Encosternum delegorguei) were the most often used NTFPs by communities in the Vhembe area. Most of the households relied on NTFPs for subsistence. At the scale of an individual, the mean number of NTFP species used was 26.8±12.6 across the five villages. When considering a household, the mean number was 36.1±10.7 species. When aggregated across the 20 households per village, the mean number per village was 105.2±34.1 species. The species accumulation curve showed that 20 households per village were reasonably representative for four of the five villages. The results from the principal component analysis (PCA) and correlation analysis revealed that age, education, and employment status were significantly associated with the number of species used by individuals, whereas gender showed no clear correlation. At the household scale, household size was positively related with the number of species used, but income level and income source were not. At the village scale, attributes such as proximity to a town, settlement type, vegetation type, and distance to a nearby savanna all had some influence on the number of NTFP species listed. Most of the respondents felt that the number of species used had increased over the last 10–15 years, although some stated the opposite. Increases were attributed by traditional councils bans, the establishment of protected areas, and restoration. Activities eroding the number of NTFP species were identified as clear felling for farming, climate change, and over-harvesting. This study suggests that communities must be made more aware of the overharvesting of NTFP species in the savanna to avoid biodiversity loss. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2023
- Full Text:
- Date Issued: 2023-03-29
- Authors: Mulaudzi, Takalani Rachel
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422481 , vital:71946
- Description: Non-Timber Forest Products (NTFPs) are wild biological resources obtained from natural landscapes, agricultural systems, and rural and urban regions for a variety of uses. NTFPs contribute significantly to livelihoods and living standards by offering a variety of socioeconomic benefits such as food, health, income generation, and safety nets. These multiple benefits are provided by a wide diversity of plant, animal and fungal species in different settings. However, the precise number of NTFP species used depends on the scale of assessment, namely use by individuals, by households and by villages. Consequently, it is difficult to compare numbers of species used between studies because of the differing scales. As a result, the objective of this study was to determine the number of NTFP species used at three different scales and how each is correlated with appropriate scale-dependent contextual variables. This objective was met by sampling individuals and whole households in five villages in the Vhembe District in Limpopo Province, South Africa. Twenty households were randomly selected in each village, providing a total sample of 100 households and 179 individuals in those households. In each household, every adult member was interviewed individually about the NTFPs that they used or knew. The major questions covered the NTFP species used, the respondents' socioeconomic level, the NTFP species used previously, and if the number of NTFP species are changing in the landscape. Data were reported per individual as well as per household and per village. The household level was derived by adding the responses of all the adults in each household but excluding duplicates. The same approach was used at the village scale, namely, the data across the 20 households were pooled, and duplicates were omitted. Patterns of NTFP use were examined by type of NTFP, and analysis using standard statistical tests, along with a Principal Components Analysis and a multivariate Detrended Correspondence Analysis of the NTFP species composition across villages. A total of 275 species of NTFPs were mentioned across the entire sample, including 81 species of firewood, 48 species of edible insects, 43 species of wild vegetables, 40 species of edible fruits, 38 species of wood utensils, 28 species of medicinal plants, 23 species of thatch grass, 19 species of poles, 19 species of wood for carvings, nine species of reeds, eight species of mushroom, and eight species of fodder. Of these species, some species had more than one use. Approximately 90% of the species used by the respondents were native species. Wild vegetables (e.g., Corchorus olitorius, Amaranthus capensis, Bidens pilosa), firewood (e.g., Colophospermum mopane, Parinari curatellifolia, Combretum hereroense), wild fruit (e.g., Landolphia kirkii, Vangueria infausta), and edible insects (e.g., Imbrasia belina, Macrotermes michaelseni, Encosternum delegorguei) were the most often used NTFPs by communities in the Vhembe area. Most of the households relied on NTFPs for subsistence. At the scale of an individual, the mean number of NTFP species used was 26.8±12.6 across the five villages. When considering a household, the mean number was 36.1±10.7 species. When aggregated across the 20 households per village, the mean number per village was 105.2±34.1 species. The species accumulation curve showed that 20 households per village were reasonably representative for four of the five villages. The results from the principal component analysis (PCA) and correlation analysis revealed that age, education, and employment status were significantly associated with the number of species used by individuals, whereas gender showed no clear correlation. At the household scale, household size was positively related with the number of species used, but income level and income source were not. At the village scale, attributes such as proximity to a town, settlement type, vegetation type, and distance to a nearby savanna all had some influence on the number of NTFP species listed. Most of the respondents felt that the number of species used had increased over the last 10–15 years, although some stated the opposite. Increases were attributed by traditional councils bans, the establishment of protected areas, and restoration. Activities eroding the number of NTFP species were identified as clear felling for farming, climate change, and over-harvesting. This study suggests that communities must be made more aware of the overharvesting of NTFP species in the savanna to avoid biodiversity loss. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2023
- Full Text:
- Date Issued: 2023-03-29
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