An in-silico study of the type II NADH: Quinone Oxidoreductase (ndh2). A new anti-malaria drug target
- Authors: Baye, Bertha Cinthia
- Date: 2022-10-14
- Subjects: Malaria , Plasmodium , Molecular dynamics , Computer simulation , Quinone , Antimalarials , Molecules Models , Docking , Drugs Computer-aided design
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365633 , vital:65767 , DOI https://doi.org/10.21504/10962/365633
- Description: Malaria is caused by Plasmodium parasites, spread to people through the bites of infected female Anopheles mosquitoes. This study focuses on all 5 (Plasmodium falciparum, Plasmodium knowlesi, Plasmodium malariae, Plasmodium ovale and Plasmodium vivax) parasites that cause malaria in humans. Africa is a developing continent, and it is the most affected with an estimation of 90% of more than 400 000 malaria-related deaths reported by the World Health Organization (WHO) report in 2020, in which 61% of that number are children under the ages of five. Malaria resistance was initially observed in early 1986 and with the progression of time anti-malarial drug resistance has only increased. As a result, there is a need to study the malarial proteins mechanism of action and identify alternative treatment strategies for this disease. Type II NADH: quinone oxidoreductase (NDH2) is a monotopic protein that catalyses the electron transfer from NADH to quinone via FAD without a proton-pumping activity, and functions as an initial enzyme, either in addition to or as an alternative to proton-pumping NADH dehydrogenase (complex I) in the respiratory chain of bacteria, archaea, and fungal and plant mitochondrial. The structures for the Plasmodium knowlesi, Plasmodium malariae, Plasmodium ovale and Plasmodium vivax were modelled from the crystal structure of Plasmodium falciparum (5JWA). Compounds from the South African natural compounds database (SANCDB) were docked against both the NDH2 crystal structure and modelled structures. By performing in silico screening the study aimed to find potential compounds that might interrupt the electron transfer to quinone therefore disturbing the enzyme‟s function and thereby possibly eliminating the plasmodium parasite. CHARMM-GUI was used to create the membrane (since this work is with membrane-bound proteins) and to orient the protein on the membrane using OPM server guidelines, the interface produced GROMACS topology files that were used in molecular dynamics simulations. Molecular dynamics simulations were performed in the Centre for high performance computing (CHPC) cluster under the CHEM0802 project and the trajectories produced were further analysed. In this work not only were hit compounds from SANCDB identified, but also differences in behaviour across species and in the presence or absence of the membrane were described. This highlights the need to include the correct protein environment when studying these systems. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Authors: Baye, Bertha Cinthia
- Date: 2022-10-14
- Subjects: Malaria , Plasmodium , Molecular dynamics , Computer simulation , Quinone , Antimalarials , Molecules Models , Docking , Drugs Computer-aided design
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365633 , vital:65767 , DOI https://doi.org/10.21504/10962/365633
- Description: Malaria is caused by Plasmodium parasites, spread to people through the bites of infected female Anopheles mosquitoes. This study focuses on all 5 (Plasmodium falciparum, Plasmodium knowlesi, Plasmodium malariae, Plasmodium ovale and Plasmodium vivax) parasites that cause malaria in humans. Africa is a developing continent, and it is the most affected with an estimation of 90% of more than 400 000 malaria-related deaths reported by the World Health Organization (WHO) report in 2020, in which 61% of that number are children under the ages of five. Malaria resistance was initially observed in early 1986 and with the progression of time anti-malarial drug resistance has only increased. As a result, there is a need to study the malarial proteins mechanism of action and identify alternative treatment strategies for this disease. Type II NADH: quinone oxidoreductase (NDH2) is a monotopic protein that catalyses the electron transfer from NADH to quinone via FAD without a proton-pumping activity, and functions as an initial enzyme, either in addition to or as an alternative to proton-pumping NADH dehydrogenase (complex I) in the respiratory chain of bacteria, archaea, and fungal and plant mitochondrial. The structures for the Plasmodium knowlesi, Plasmodium malariae, Plasmodium ovale and Plasmodium vivax were modelled from the crystal structure of Plasmodium falciparum (5JWA). Compounds from the South African natural compounds database (SANCDB) were docked against both the NDH2 crystal structure and modelled structures. By performing in silico screening the study aimed to find potential compounds that might interrupt the electron transfer to quinone therefore disturbing the enzyme‟s function and thereby possibly eliminating the plasmodium parasite. CHARMM-GUI was used to create the membrane (since this work is with membrane-bound proteins) and to orient the protein on the membrane using OPM server guidelines, the interface produced GROMACS topology files that were used in molecular dynamics simulations. Molecular dynamics simulations were performed in the Centre for high performance computing (CHPC) cluster under the CHEM0802 project and the trajectories produced were further analysed. In this work not only were hit compounds from SANCDB identified, but also differences in behaviour across species and in the presence or absence of the membrane were described. This highlights the need to include the correct protein environment when studying these systems. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
Mentoring as social learning value creation in two South African environmental organisations: a social realist analysis
- Authors: Hiestermann, Michelle
- Date: 2022-10-14
- Subjects: Social realism , Social learning , Mentoring , Environmental education South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366248 , vital:65846 , https://doi.org/10.21504/10962/366248
- Description: South Africa is facing overwhelming crises of educational quality, record rates of unemployment (especially amongst youth) and environmental issues and risks, further exacerbated by the Covid-19 pandemic. Environmental education research that addresses these challenges is critical to ensuring that future generations thrive in a warming climate. South Africa needs environmental leaders; we therefore need to understand and explore the possibilities of mentoring young professionals in environmental organisations in South Africa. Several initiatives have been developed to contribute to the mentoring of young professionals in South African environmental organisations. This study drew on a critical realist ontology, social realist meta-theory and domain specific theory on mentoring and evaluation to explore mentoring as a value creating proposition in two environmental organisations in South Africa that were part of the national Groen Sebenza youth employment creation programme which had a strong focus on mentoring. To strengthen conceptual analytical tools on mentoring, I undertook an immanent critique of domain specific mentoring theory to develop a more appropriate foundation for mentoring theory in the environmental sector that was not subject to the historical influence of human capital theory only (which has tended to dominate the field’s literature). I then developed in-depth understanding of mentoring in two case study contexts, namely a non-profit environmental organisation and an environmental consulting company, using qualitative research approaches that included contextual profiling, case study research and mirror data workshops. Analytically, I considered the case data drawing on the value creation evaluation framework of Wenger-Trayner and Wenger-Trayner (2014) which itself was developing as an analytical framework as the study developed. I strengthened the analytical framework with social realist interpretations drawing on Archer (1995). This offered me a way of developing an in-depth understanding of the factors which constrain or enable the value creation possibilities of mentoring, with a view to inform human capacity development initiatives that support mentoring in the environment sector. It was possible to explain the value creation possibilities of mentoring within two case study environmental organisations through considering mentoring as a social learning process of value creation and this overcame some of the shortfalls identified in other early learning theories as well as theories of mentoring. The research revealed how mentoring can provide a value creation social learning trajectory for unemployed youth. A social realist perspective explained how young professionals expanded their primary agency, through full participation in workplace communities of practice, to find their identity as corporate agents in the workplace with their mentors. In this research, Social Realist ontology, theory and methodology was able to achieve what Human Capital Theory could not and provided an account of the interplay of structure, culture and agency over time, through emergent properties and the separation of structure and agency. Thus, it was possible to avoid conflation and the limitation of theory of the present tense, with a deeper, ontologically robust explanation of mentoring as social learning and social change and a social realist orientation to human capacity development. South Africa has a history of oppression, inequality and injustice and requires social processes that are reflexive, critical, emancipatory and transformative. Therefore, this research required theory and approaches that could explain mentoring of unemployed youth, as a common good initiative for a more just and sustainable society. As shown in this study, a Social Realist approach can uncover the underlying generative mechanisms and make the implicit more explicit in research, policy and strategy, offering a robust alternative to the tenets of Human Capital Theory that have driven much mentoring research in South Africa and elsewhere to date. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Authors: Hiestermann, Michelle
- Date: 2022-10-14
- Subjects: Social realism , Social learning , Mentoring , Environmental education South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366248 , vital:65846 , https://doi.org/10.21504/10962/366248
- Description: South Africa is facing overwhelming crises of educational quality, record rates of unemployment (especially amongst youth) and environmental issues and risks, further exacerbated by the Covid-19 pandemic. Environmental education research that addresses these challenges is critical to ensuring that future generations thrive in a warming climate. South Africa needs environmental leaders; we therefore need to understand and explore the possibilities of mentoring young professionals in environmental organisations in South Africa. Several initiatives have been developed to contribute to the mentoring of young professionals in South African environmental organisations. This study drew on a critical realist ontology, social realist meta-theory and domain specific theory on mentoring and evaluation to explore mentoring as a value creating proposition in two environmental organisations in South Africa that were part of the national Groen Sebenza youth employment creation programme which had a strong focus on mentoring. To strengthen conceptual analytical tools on mentoring, I undertook an immanent critique of domain specific mentoring theory to develop a more appropriate foundation for mentoring theory in the environmental sector that was not subject to the historical influence of human capital theory only (which has tended to dominate the field’s literature). I then developed in-depth understanding of mentoring in two case study contexts, namely a non-profit environmental organisation and an environmental consulting company, using qualitative research approaches that included contextual profiling, case study research and mirror data workshops. Analytically, I considered the case data drawing on the value creation evaluation framework of Wenger-Trayner and Wenger-Trayner (2014) which itself was developing as an analytical framework as the study developed. I strengthened the analytical framework with social realist interpretations drawing on Archer (1995). This offered me a way of developing an in-depth understanding of the factors which constrain or enable the value creation possibilities of mentoring, with a view to inform human capacity development initiatives that support mentoring in the environment sector. It was possible to explain the value creation possibilities of mentoring within two case study environmental organisations through considering mentoring as a social learning process of value creation and this overcame some of the shortfalls identified in other early learning theories as well as theories of mentoring. The research revealed how mentoring can provide a value creation social learning trajectory for unemployed youth. A social realist perspective explained how young professionals expanded their primary agency, through full participation in workplace communities of practice, to find their identity as corporate agents in the workplace with their mentors. In this research, Social Realist ontology, theory and methodology was able to achieve what Human Capital Theory could not and provided an account of the interplay of structure, culture and agency over time, through emergent properties and the separation of structure and agency. Thus, it was possible to avoid conflation and the limitation of theory of the present tense, with a deeper, ontologically robust explanation of mentoring as social learning and social change and a social realist orientation to human capacity development. South Africa has a history of oppression, inequality and injustice and requires social processes that are reflexive, critical, emancipatory and transformative. Therefore, this research required theory and approaches that could explain mentoring of unemployed youth, as a common good initiative for a more just and sustainable society. As shown in this study, a Social Realist approach can uncover the underlying generative mechanisms and make the implicit more explicit in research, policy and strategy, offering a robust alternative to the tenets of Human Capital Theory that have driven much mentoring research in South Africa and elsewhere to date. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
Stock structure of Patagonian toothfish Dissostichus eleginoides (Smitt 1898, family Nototheniidae) in the Southwest Atlantic
- Authors: Lee, Brendon
- Date: 2022-10-14
- Subjects: Otoliths , Patagonian toothfish Geographical distribution , Fish tagging , Biogeography , Microstructure , Microchemistry
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365599 , vital:65763 , DOI https://doi.org/10.21504/10962/365599
- Description: The identification of discrete self-sustaining productive units in marine populations is essential for achieving sustainable fisheries objectives. Marine fish populations frequently exhibit dynamic characteristics across their life-histories, displaying variability in spatial structure and mixing patterns, both within and among populations. The incoherent application of management boundaries on biological populations can bias stock assessment results and have important implications on sustainable fisheries management. Patagonian toothfish (Dissostichus eleginoides) is a long-lived, slow-growing, late-maturing, deep-sea, benthopelagic species. It forms the basis of important and highly lucrative industrial and artisanal fisheries across its distribution. Patagonian toothfish have complex life-histories characterised by high dispersal potential during the egg and larval phase, a wide depth range because of their ontogenetic migratory behaviour, and large adult size that is capable of undertaking long-distance active movements (>200 km). These characteristics provide opportunities for high levels of connectivity, and as such, the stock structure is not well understood. We applied an integrated, multidisciplinary approach to provide an improved understanding of the complex stock structure dynamics for Patagonian toothfish on the Patagonian Shelf, specifically in relation to the shelf, slope, and deep-sea plains around the Falkland Islands. Research results were focused on aspects pertaining to (1) geographic variation in phenotypic characters (otolith shape); (2) a description of the spatial-temporal distribution patterns; (3) the active movements of deep-sea adults (tag-recapture study); and (4) the identification of early life-history dispersal through otolith microstructure and microchemical chronologies. Results from the study indicate high regional connectivity during the early life-history stages derived from at least two spawning contingents into spatially discrete nursery areas (cohort groups) on the Falklands Shelf. Fish followed distinct ontogenetic pathways into deeper waters adjacent to the areas wherein juvenile settlement into a demersal habitat occurred. There is little to no evidence of mixing among cohort groups during their ontogenetic migration into deep-sea adult habitats, reflecting a mixed population based on oceanographically defined egg and larval dispersal. The majority of the adult component of the population continue to display high site fidelity. However, between 9 and 25% of the population, consisting predominantly of larger reproductively capable adults undertake long-distance dispersal behaviour, identified as home-range relocations from the adult deep-sea habitats towards three of the known southern spawning grounds in the region. Results are suggestive of a requirement for improved collaborative efforts for regionally-based management approaches with careful consideration of local stock contingents. Future monitoring and research priorities should focus on the identification of reproductive potential, dispersal pathways and settlement patterns of stock contingents to inform the dynamics of mixed stock origins across the Patagonian region. While many aspects regarding the stock structure remain unresolved, results derived from the current studies can be used to inform the development of management measures to ensure the continued recovery and sustainable management of Patagonian toothfish within the region. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Authors: Lee, Brendon
- Date: 2022-10-14
- Subjects: Otoliths , Patagonian toothfish Geographical distribution , Fish tagging , Biogeography , Microstructure , Microchemistry
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365599 , vital:65763 , DOI https://doi.org/10.21504/10962/365599
- Description: The identification of discrete self-sustaining productive units in marine populations is essential for achieving sustainable fisheries objectives. Marine fish populations frequently exhibit dynamic characteristics across their life-histories, displaying variability in spatial structure and mixing patterns, both within and among populations. The incoherent application of management boundaries on biological populations can bias stock assessment results and have important implications on sustainable fisheries management. Patagonian toothfish (Dissostichus eleginoides) is a long-lived, slow-growing, late-maturing, deep-sea, benthopelagic species. It forms the basis of important and highly lucrative industrial and artisanal fisheries across its distribution. Patagonian toothfish have complex life-histories characterised by high dispersal potential during the egg and larval phase, a wide depth range because of their ontogenetic migratory behaviour, and large adult size that is capable of undertaking long-distance active movements (>200 km). These characteristics provide opportunities for high levels of connectivity, and as such, the stock structure is not well understood. We applied an integrated, multidisciplinary approach to provide an improved understanding of the complex stock structure dynamics for Patagonian toothfish on the Patagonian Shelf, specifically in relation to the shelf, slope, and deep-sea plains around the Falkland Islands. Research results were focused on aspects pertaining to (1) geographic variation in phenotypic characters (otolith shape); (2) a description of the spatial-temporal distribution patterns; (3) the active movements of deep-sea adults (tag-recapture study); and (4) the identification of early life-history dispersal through otolith microstructure and microchemical chronologies. Results from the study indicate high regional connectivity during the early life-history stages derived from at least two spawning contingents into spatially discrete nursery areas (cohort groups) on the Falklands Shelf. Fish followed distinct ontogenetic pathways into deeper waters adjacent to the areas wherein juvenile settlement into a demersal habitat occurred. There is little to no evidence of mixing among cohort groups during their ontogenetic migration into deep-sea adult habitats, reflecting a mixed population based on oceanographically defined egg and larval dispersal. The majority of the adult component of the population continue to display high site fidelity. However, between 9 and 25% of the population, consisting predominantly of larger reproductively capable adults undertake long-distance dispersal behaviour, identified as home-range relocations from the adult deep-sea habitats towards three of the known southern spawning grounds in the region. Results are suggestive of a requirement for improved collaborative efforts for regionally-based management approaches with careful consideration of local stock contingents. Future monitoring and research priorities should focus on the identification of reproductive potential, dispersal pathways and settlement patterns of stock contingents to inform the dynamics of mixed stock origins across the Patagonian region. While many aspects regarding the stock structure remain unresolved, results derived from the current studies can be used to inform the development of management measures to ensure the continued recovery and sustainable management of Patagonian toothfish within the region. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
The incorporation of GeoGebra as a visualisation tool to teach calculus in teacher education institutions: the Zambian case
- Authors: Kangwa, Lemmy
- Date: 2022-10-14
- Subjects: GeoGebra , Calculus Study and teaching (Secondary) Zambia , Visual learning
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405470 , vital:70174 , DOI
- Description: This qualitative case study investigated teacher educators’ (lecturers) use of the dynamic mathematics software, GeoGebra, to teach calculus in three teacher education institutions (TEIs) in Zambia. Visualisation, a key characteristic of GeoGebra, is increasingly gaining recognition of playing a critical role in mathematics teaching and learning, especially in problem solving tasks. It is considered a powerful didactical tool for students to construct mental and physical representations that can enhance conceptual understanding of mathematics. GeoGebra is a visualisation tool that can be used for problem-oriented teaching and foster mathematical experiments and discoveries. GeoGebra’s inherent visualisation characteristics align well with the teaching of calculus, the mathematical domain of this study. The study (whose research methodology was underpinned by the interpretive paradigm) was undertaken with a broader goal of designing and implementing GeoGebra applets and instructional materials on various calculus topics. The study is located within the “Teaching and Learning Mathematics with GeoGebra (TLMG) project” – a project that involves mathematics teachers and lecturers in Zambia. The case in this study is the six mathematics lecturers who co-designed and used GeoGebra applets to teach derivatives and integrals to pre-service mathematics teachers in TEIs. The unit of analysis therefore is the six lecturers’ use of GeoGebra as a visualisation tool to teach calculus to enhance conceptual understanding, their perceptions and experiences of using GeoGebra and the enabling and constraining factors of using GeoGebra to teach and learn mathematics. The data for the study were video recordings of observations and interviews of lecturers. The data was analysed thematically and was guided and informed by an analytical framework adopted from the theory of constructivism – the umbrella theoretical framework of this study – and the models of Technological Pedagogical Content Knowledge (TPACK), and the Technology Acceptance Model (TAM). A detailed analysis of the lecturers’ interactions with the applets enabled me to gain insights into the participants’ experiences and perceptions of GeoGebra applets in the teaching and learning process. The findings of the study revealed that the visualisation characteristics of GeoGebra generally enhanced the conceptual understanding of calculus. It also revealed that adequate training, coupled with sufficient knowledge of the subject matter in calculus, were necessary for lecturers to use GeoGebra effectively, and that the lack of resources and expertise were major hindrances in the use of GeoGebra to teach mathematics in TEIs. It also revealed that there is a need to equip GeoGebra with other features that would make it more versatile, and suggested a teaching approach that would complement the use of conventional methods and GeoGebra to provide a link between abstract and concrete concepts of calculus. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Authors: Kangwa, Lemmy
- Date: 2022-10-14
- Subjects: GeoGebra , Calculus Study and teaching (Secondary) Zambia , Visual learning
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405470 , vital:70174 , DOI
- Description: This qualitative case study investigated teacher educators’ (lecturers) use of the dynamic mathematics software, GeoGebra, to teach calculus in three teacher education institutions (TEIs) in Zambia. Visualisation, a key characteristic of GeoGebra, is increasingly gaining recognition of playing a critical role in mathematics teaching and learning, especially in problem solving tasks. It is considered a powerful didactical tool for students to construct mental and physical representations that can enhance conceptual understanding of mathematics. GeoGebra is a visualisation tool that can be used for problem-oriented teaching and foster mathematical experiments and discoveries. GeoGebra’s inherent visualisation characteristics align well with the teaching of calculus, the mathematical domain of this study. The study (whose research methodology was underpinned by the interpretive paradigm) was undertaken with a broader goal of designing and implementing GeoGebra applets and instructional materials on various calculus topics. The study is located within the “Teaching and Learning Mathematics with GeoGebra (TLMG) project” – a project that involves mathematics teachers and lecturers in Zambia. The case in this study is the six mathematics lecturers who co-designed and used GeoGebra applets to teach derivatives and integrals to pre-service mathematics teachers in TEIs. The unit of analysis therefore is the six lecturers’ use of GeoGebra as a visualisation tool to teach calculus to enhance conceptual understanding, their perceptions and experiences of using GeoGebra and the enabling and constraining factors of using GeoGebra to teach and learn mathematics. The data for the study were video recordings of observations and interviews of lecturers. The data was analysed thematically and was guided and informed by an analytical framework adopted from the theory of constructivism – the umbrella theoretical framework of this study – and the models of Technological Pedagogical Content Knowledge (TPACK), and the Technology Acceptance Model (TAM). A detailed analysis of the lecturers’ interactions with the applets enabled me to gain insights into the participants’ experiences and perceptions of GeoGebra applets in the teaching and learning process. The findings of the study revealed that the visualisation characteristics of GeoGebra generally enhanced the conceptual understanding of calculus. It also revealed that adequate training, coupled with sufficient knowledge of the subject matter in calculus, were necessary for lecturers to use GeoGebra effectively, and that the lack of resources and expertise were major hindrances in the use of GeoGebra to teach mathematics in TEIs. It also revealed that there is a need to equip GeoGebra with other features that would make it more versatile, and suggested a teaching approach that would complement the use of conventional methods and GeoGebra to provide a link between abstract and concrete concepts of calculus. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
The nexus between territorial border controls, informal cross border trading and economic security in Zimbabwe: the case of Beitbridge Border Post
- Authors: Nare, Hilary
- Date: 2022-10-14
- Subjects: Informal sector (Economics) Zimbabwe , South Africa Commerce Zimbabwe , Border security Zimbabwe , Economic security Zimbabwe , Beitbridge (Zimbabwe) , Zimbabwe Politics and government , Zimbabwe Economic conditions
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365977 , vital:65807 , DOI https://doi.org/10.21504/10962/365977
- Description: Informal cross border trade is central to the lives of many Zimbabweans, with informal trade across the Zimbabwean-South African border being of particular importance. This entails travelling through the Beitbridge border post on the Zimbabwean side, with Zimbabwean informal traders purchasing items in South Africa for resale in Zimbabwe. In doing so, they contribute not only to their own economic security but likely to the economic security of other Zimbabweans deeply affected by the ongoing crisis in the country. Often times, when examining the lives of Zimbabwe’s informal traders, the border post is not subjected to sustained focus and analysis. Yet, border posts (like the Beitbridge border post) are complex social institutions which configure the lives and livelihoods of cross border traders in multiple ways, and which informal traders often have to negotiate their way through. In this context, this thesis provides a critical analysis of border control management at the Beitbridge border post with particular reference to the activities of Zimbabwean informal cross border traders. The Beitbridge border post, like all border posts, has multiple functions. As a territorial border post, it seeks to maintain the national sovereignty of the Zimbabwean nation- state, and it monitors and controls the movement of people and goods in both directions. Currently, it is doing so at a time when the vast majority of Zimbabweans are suffering from varying levels of economic insecurity. The extent to which these functions are performed, and the manner in which they are performed, depends fundamentally on what takes place at the Beitbridge border post. This refers to the performance of both human subjects (border control officers of various kinds) and inanimate objects (such as scanners and cameras), both of which enact agency. Combined with these is the agency of cross border traders, who are compelled to navigate their way in and through these dimensions of the border control system. The thesis examines this by drawing heavily upon Actor-Network Theory. It is based on research undertaken at Beitbridge border post, involving 50 interviews with primarily current and former border control officers as well as informal cross border traders. Findings of this study show that deficiencies in border control management and border porosity at Beitbridge have led to a flourishing of informal cross border trade and, in turn, contributed to economic security in Zimbabwe, including during the time of Covid-19. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Authors: Nare, Hilary
- Date: 2022-10-14
- Subjects: Informal sector (Economics) Zimbabwe , South Africa Commerce Zimbabwe , Border security Zimbabwe , Economic security Zimbabwe , Beitbridge (Zimbabwe) , Zimbabwe Politics and government , Zimbabwe Economic conditions
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365977 , vital:65807 , DOI https://doi.org/10.21504/10962/365977
- Description: Informal cross border trade is central to the lives of many Zimbabweans, with informal trade across the Zimbabwean-South African border being of particular importance. This entails travelling through the Beitbridge border post on the Zimbabwean side, with Zimbabwean informal traders purchasing items in South Africa for resale in Zimbabwe. In doing so, they contribute not only to their own economic security but likely to the economic security of other Zimbabweans deeply affected by the ongoing crisis in the country. Often times, when examining the lives of Zimbabwe’s informal traders, the border post is not subjected to sustained focus and analysis. Yet, border posts (like the Beitbridge border post) are complex social institutions which configure the lives and livelihoods of cross border traders in multiple ways, and which informal traders often have to negotiate their way through. In this context, this thesis provides a critical analysis of border control management at the Beitbridge border post with particular reference to the activities of Zimbabwean informal cross border traders. The Beitbridge border post, like all border posts, has multiple functions. As a territorial border post, it seeks to maintain the national sovereignty of the Zimbabwean nation- state, and it monitors and controls the movement of people and goods in both directions. Currently, it is doing so at a time when the vast majority of Zimbabweans are suffering from varying levels of economic insecurity. The extent to which these functions are performed, and the manner in which they are performed, depends fundamentally on what takes place at the Beitbridge border post. This refers to the performance of both human subjects (border control officers of various kinds) and inanimate objects (such as scanners and cameras), both of which enact agency. Combined with these is the agency of cross border traders, who are compelled to navigate their way in and through these dimensions of the border control system. The thesis examines this by drawing heavily upon Actor-Network Theory. It is based on research undertaken at Beitbridge border post, involving 50 interviews with primarily current and former border control officers as well as informal cross border traders. Findings of this study show that deficiencies in border control management and border porosity at Beitbridge have led to a flourishing of informal cross border trade and, in turn, contributed to economic security in Zimbabwe, including during the time of Covid-19. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
The role of visualisation in redefining the pedagogy of fractions in mathematics classrooms among senior primary school teachers
- Authors: Ausiku, Charity Makwiliro
- Date: 2022-10-14
- Subjects: Mathematics Study and teaching (Elementary) Namibia , Fractions Study and teaching (Elementary) Namibia , Visualization , Visual learning , Dual-coding hypothesis , Constructivism (Education) Namibia
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405456 , vital:70173 , DOI 10.21504/10962/405456
- Description: This mixed methods study explored the impact of the use of a visualisation approach on the pedagogy of eight teacher participants who were involved in the Rundu Campus Fraction Project (RCFP). The aim of this study was to determine the extent to which participants incorporated visualisation processes in the pedagogy of fractions, in view of their exposure to visualisation activities in the RCFP. Since fractions are difficult to teach and learn, visualisation was considered as an alternative approach to the pedagogy of fractions because it presents learners with opportunities to improve their proportional and spatial reasoning. This study was founded on the premise that the incorporation of both verbal and nonverbal cues can enhance the teaching and learning of fractions rather than the use of a single cue. Hence, the two theories underpinning this study are the Dual Coding Theory and the Constructivist Theory. While the Dual Coding Theory advocates for the use of verbal and nonverbal codes, the Constructivist theory states that meaningful learning occurs when learners are presented with opportunities to construct their own knowledge. Thus, the two codes are intertwined. In other words, the active construction of knowledge among learners is aided by using constructivist teaching approaches through the incorporation of both verbal and nonverbal codes. Although this study was predominantly qualitative, quantitative methods were also used in the data collection process. A questionnaire was administered to identify teacher participants for this study, based on their teaching orientations. Their views on best practices in mathematics classrooms in general and the incorporation of visualisation processes in particular, were instrumental in the selection of participants for this study. In addition, observations and semi-structured interviews were also used as research methods. Twenty-five lesson samples were video recorded, transcribed and analysed using both qualitative and quantitative methods. Moreover, each of the eight participants was exposed to a set of pre- and post-observation interviews during which they were expected to express their views on the selection, incorporation and impact of visualisation processes on the teaching of fractions. Data sets from all three instruments were analysed using both quantitative and qualitative methods. The findings indicate that the RCFP had an impact on the teaching strategies employed by the participants as they all incorporated visualisation processes into their teaching to some extent. In some lessons, the visual code was effectively blended into the verbal code while in others, the purpose of and connection between the two codes was not evident. Hence, although all the participants embraced the incorporation of visualisation in the pedagogy of mathematics, some of them struggled to find its rightful position in the teaching of fractions. The findings suggest that despite the participants’ eagerness to use visualisation in their fraction lessons, some of them did not have adequate knowledge to successfully merge it with the conventional verbal code. Thus, for the integration of visuals to be impactful, it should be carefully merged in the teaching of fractions by taking into account various factors. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Authors: Ausiku, Charity Makwiliro
- Date: 2022-10-14
- Subjects: Mathematics Study and teaching (Elementary) Namibia , Fractions Study and teaching (Elementary) Namibia , Visualization , Visual learning , Dual-coding hypothesis , Constructivism (Education) Namibia
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405456 , vital:70173 , DOI 10.21504/10962/405456
- Description: This mixed methods study explored the impact of the use of a visualisation approach on the pedagogy of eight teacher participants who were involved in the Rundu Campus Fraction Project (RCFP). The aim of this study was to determine the extent to which participants incorporated visualisation processes in the pedagogy of fractions, in view of their exposure to visualisation activities in the RCFP. Since fractions are difficult to teach and learn, visualisation was considered as an alternative approach to the pedagogy of fractions because it presents learners with opportunities to improve their proportional and spatial reasoning. This study was founded on the premise that the incorporation of both verbal and nonverbal cues can enhance the teaching and learning of fractions rather than the use of a single cue. Hence, the two theories underpinning this study are the Dual Coding Theory and the Constructivist Theory. While the Dual Coding Theory advocates for the use of verbal and nonverbal codes, the Constructivist theory states that meaningful learning occurs when learners are presented with opportunities to construct their own knowledge. Thus, the two codes are intertwined. In other words, the active construction of knowledge among learners is aided by using constructivist teaching approaches through the incorporation of both verbal and nonverbal codes. Although this study was predominantly qualitative, quantitative methods were also used in the data collection process. A questionnaire was administered to identify teacher participants for this study, based on their teaching orientations. Their views on best practices in mathematics classrooms in general and the incorporation of visualisation processes in particular, were instrumental in the selection of participants for this study. In addition, observations and semi-structured interviews were also used as research methods. Twenty-five lesson samples were video recorded, transcribed and analysed using both qualitative and quantitative methods. Moreover, each of the eight participants was exposed to a set of pre- and post-observation interviews during which they were expected to express their views on the selection, incorporation and impact of visualisation processes on the teaching of fractions. Data sets from all three instruments were analysed using both quantitative and qualitative methods. The findings indicate that the RCFP had an impact on the teaching strategies employed by the participants as they all incorporated visualisation processes into their teaching to some extent. In some lessons, the visual code was effectively blended into the verbal code while in others, the purpose of and connection between the two codes was not evident. Hence, although all the participants embraced the incorporation of visualisation in the pedagogy of mathematics, some of them struggled to find its rightful position in the teaching of fractions. The findings suggest that despite the participants’ eagerness to use visualisation in their fraction lessons, some of them did not have adequate knowledge to successfully merge it with the conventional verbal code. Thus, for the integration of visuals to be impactful, it should be carefully merged in the teaching of fractions by taking into account various factors. , Thesis (PhD) -- Faculty of Education, Education, 2022
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