Moult and energetics in three species from the Euplectes genus representing a gradient of elaborate plumage ornamentation
- Authors: Webb, Stacey Leigh
- Date: 2022-12
- Subjects: Sexual selection in animals – South Africa , Bird watching -- Africa, Southern , Plumage
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/60026 , vital:62734
- Description: Elaborate plumage ornamentation in birds has fascinated scientists since the 1800s. The evolution and persistence of elaborate and costly ornamentation seemed to be in opposition to the theory of natural selection. However, over the years research has revealed the role and functional significance of elaborate plumage ornamentation in sexual selection. Recent studies have shown that the energetic costs associated with moulting into new plumages are higher than maintenance costs, but these costs have not been quantified for species that exhibit elaborate breeding plumage ornamentation for sexual selection. In addition, for these sexually selected ornamental traits (signals) to have evolved and be maintained, there must be some aspect of individual quality that they convey to the receiver. Despite a large body of literature on sexual selection, honest signalling and ornamental plumage in birds, the physiological correlates of honest signalling during sexual selection and the messages these signals convey to the receivers are poorly understood. In this study, I investigated four aspects related to the honesty of the sexual selection signal. These were (i) seasonal variation in standardised resting metabolic rates of breeding and non-breeding birds, (ii) moult phenology, (iii) physiological parameters linked to honest signalling, and (iv) the energetic costs of production and maintenance of elaborate plumage ornamentation using three species from the Euplectes genus as model species. The three species selected, the red-collared widowbird (Euplectes ardens), fan-tailed widowbird (Euplectes axillaris) and the southern red bishop (Euplectes orix) represent a gradient of plumage elaboration and although the receivers of the sexual selection signals are known for these three species, the energetic cost of the signals and the underlying message the signals convey remain unknown. I measured seasonal variation in resting metabolic rate (RMR), body mass (Mb), thermoneutral zone (TNZ) and body temperature (Tb) over the course of two years in the three selected Euplectes species (E. ardens, E. axillaris and E. orix; chapter 2). My results showed no significant effect of season on RMR (except in E. orix females) suggesting that in these species the metabolic costs in summer (associated with breeding season) are comparable to the metabolic costs associated with thermoregulation during winter. Contrary to my prediction that metabolic costs would increase along a gradient of increasing tail length (due to the energetic costs Webb V associated with elaborate plumage ornamentation), I found no significant effect of species. The lack of a significant result indicates that once the initial investment in plumage is complete, other predictor variables play a role (in this case body mass). , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-12
- Authors: Webb, Stacey Leigh
- Date: 2022-12
- Subjects: Sexual selection in animals – South Africa , Bird watching -- Africa, Southern , Plumage
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/60026 , vital:62734
- Description: Elaborate plumage ornamentation in birds has fascinated scientists since the 1800s. The evolution and persistence of elaborate and costly ornamentation seemed to be in opposition to the theory of natural selection. However, over the years research has revealed the role and functional significance of elaborate plumage ornamentation in sexual selection. Recent studies have shown that the energetic costs associated with moulting into new plumages are higher than maintenance costs, but these costs have not been quantified for species that exhibit elaborate breeding plumage ornamentation for sexual selection. In addition, for these sexually selected ornamental traits (signals) to have evolved and be maintained, there must be some aspect of individual quality that they convey to the receiver. Despite a large body of literature on sexual selection, honest signalling and ornamental plumage in birds, the physiological correlates of honest signalling during sexual selection and the messages these signals convey to the receivers are poorly understood. In this study, I investigated four aspects related to the honesty of the sexual selection signal. These were (i) seasonal variation in standardised resting metabolic rates of breeding and non-breeding birds, (ii) moult phenology, (iii) physiological parameters linked to honest signalling, and (iv) the energetic costs of production and maintenance of elaborate plumage ornamentation using three species from the Euplectes genus as model species. The three species selected, the red-collared widowbird (Euplectes ardens), fan-tailed widowbird (Euplectes axillaris) and the southern red bishop (Euplectes orix) represent a gradient of plumage elaboration and although the receivers of the sexual selection signals are known for these three species, the energetic cost of the signals and the underlying message the signals convey remain unknown. I measured seasonal variation in resting metabolic rate (RMR), body mass (Mb), thermoneutral zone (TNZ) and body temperature (Tb) over the course of two years in the three selected Euplectes species (E. ardens, E. axillaris and E. orix; chapter 2). My results showed no significant effect of season on RMR (except in E. orix females) suggesting that in these species the metabolic costs in summer (associated with breeding season) are comparable to the metabolic costs associated with thermoregulation during winter. Contrary to my prediction that metabolic costs would increase along a gradient of increasing tail length (due to the energetic costs Webb V associated with elaborate plumage ornamentation), I found no significant effect of species. The lack of a significant result indicates that once the initial investment in plumage is complete, other predictor variables play a role (in this case body mass). , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-12
Participatory communications as a tool for women’s empowerment: A study of five community radio stations in Northern Ghana
- Authors: Asuman, Kofi Antwi Manfred
- Date: 2022-12
- Subjects: Women in agriculture -- Africa -- Ghana , Agricultural development , Community radios – Ghana
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/59293 , vital:62026
- Description: In the process of achieving social equity and local development in Ghana, the empowerment and improvement of the lives of women remain critical factors, because of the existing role women and girls assume in the household and larger communal setting. In Northern Ghana culture and religion have historically side-lined, and in some cases, completely excluded women from participating in the dialogues, economic and political processes that lead to, or facilitate the transformation and development of their households and communities. Even though the media has largely contributed to the discrimination and stereotype of women through how women are represented in mainstream media, the Ghanaian media, in its assumed role as the “fourth estate of the realm” has the power to explicitly advocate and implicitly frame messages which can accelerate the processes of social change, women’s empowerment and social inclusion through the community radio broadcast system (Diedong, 2017: pp. 59, 64). After 30 years of the liberalization of the Ghanaian media and 25 years after the opening of the first community radio station, there have been few studies of how community radio influences women’s empowerment, how it gives opportunity for women to participate in political processes and whether, and how, it strengthens the livelihood capabilities of women. This research was motivated by the empowerment theory and the theory of participatory development communications. The researcher also makes references to feminist media theory in his arguments about the need for women to have access to radio in order to make their own content and also listen to content produced by other women. This study adopted a mixed methods research approach and collected data through programme analysis of the sampled radio stations, focus group discussions and semi-structured interviews. After field data was collected, they were analysed in themes that focus on the objectives of this study, data is presented through thematic discourse methods in order to help the researcher draw conclusions and propose a framework to guide practitioners in the implementation of communication for development projects which use mass media in targeting women for development objectives. My analyses are broadly presented in three chapters with each chapter focusing on one research objective. Based on the data, the researcher discovered that, community radio improves the livelihoods of women in Northern Ghana by providing them with agricultural programming which teaches women new farming techniques and how to practice sustainable agriculture while improving the yield of their crops. The study also found out that community radio provides. opportunities for women to monitor how public funds meant for community development projects are allocated, disbursed, and used for their intended purposes, by creating an avenue of two-way communication and dialogue between women, their district officers, and their elected leaders. Based on the findings of the study, the researcher concludes that, it is important for development practitioners who use mass media to implement women-focused projects to conduct a contextual analysis of the communities, the women, and the identified stakeholders of the intended project because every community is unique. Whereas all women in rural areas are vulnerable and underprivileged. To some extent, their needs and preferences are different because of their different levels of education and income status. , Thesis (PhD) -- Faculty of Humanities, School of Language and Communications, 2022
- Full Text:
- Date Issued: 2022-12
- Authors: Asuman, Kofi Antwi Manfred
- Date: 2022-12
- Subjects: Women in agriculture -- Africa -- Ghana , Agricultural development , Community radios – Ghana
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/59293 , vital:62026
- Description: In the process of achieving social equity and local development in Ghana, the empowerment and improvement of the lives of women remain critical factors, because of the existing role women and girls assume in the household and larger communal setting. In Northern Ghana culture and religion have historically side-lined, and in some cases, completely excluded women from participating in the dialogues, economic and political processes that lead to, or facilitate the transformation and development of their households and communities. Even though the media has largely contributed to the discrimination and stereotype of women through how women are represented in mainstream media, the Ghanaian media, in its assumed role as the “fourth estate of the realm” has the power to explicitly advocate and implicitly frame messages which can accelerate the processes of social change, women’s empowerment and social inclusion through the community radio broadcast system (Diedong, 2017: pp. 59, 64). After 30 years of the liberalization of the Ghanaian media and 25 years after the opening of the first community radio station, there have been few studies of how community radio influences women’s empowerment, how it gives opportunity for women to participate in political processes and whether, and how, it strengthens the livelihood capabilities of women. This research was motivated by the empowerment theory and the theory of participatory development communications. The researcher also makes references to feminist media theory in his arguments about the need for women to have access to radio in order to make their own content and also listen to content produced by other women. This study adopted a mixed methods research approach and collected data through programme analysis of the sampled radio stations, focus group discussions and semi-structured interviews. After field data was collected, they were analysed in themes that focus on the objectives of this study, data is presented through thematic discourse methods in order to help the researcher draw conclusions and propose a framework to guide practitioners in the implementation of communication for development projects which use mass media in targeting women for development objectives. My analyses are broadly presented in three chapters with each chapter focusing on one research objective. Based on the data, the researcher discovered that, community radio improves the livelihoods of women in Northern Ghana by providing them with agricultural programming which teaches women new farming techniques and how to practice sustainable agriculture while improving the yield of their crops. The study also found out that community radio provides. opportunities for women to monitor how public funds meant for community development projects are allocated, disbursed, and used for their intended purposes, by creating an avenue of two-way communication and dialogue between women, their district officers, and their elected leaders. Based on the findings of the study, the researcher concludes that, it is important for development practitioners who use mass media to implement women-focused projects to conduct a contextual analysis of the communities, the women, and the identified stakeholders of the intended project because every community is unique. Whereas all women in rural areas are vulnerable and underprivileged. To some extent, their needs and preferences are different because of their different levels of education and income status. , Thesis (PhD) -- Faculty of Humanities, School of Language and Communications, 2022
- Full Text:
- Date Issued: 2022-12
Spatial and temporal analysis of the critical zone in the Western rift valley corridor: towards earth stewardship science in East Africa
- Authors: Miller, Warren David
- Date: 2022-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/59771 , vital:62423
- Description: Over the coming decades, Africa is expected to experience disturbing effects due to climate change and increased land cover change due to human influences presenting a significant concern for the future well-being of human and biological systems, the latter being the foundation of ecosystem services supplied to humanity. Therefore, unprecedented transdisciplinary cooperation, coordination, and integration amongst researchers, government, and civil society are necessary to increase the resiliency of these systems. This study aims to provide an outline of the Africa Alive Corridors (AAC) as an essential model for the encouragement of sustainable development through Earth Stewardship science. These aims are accompanied by the quantification and forward modelling for land cover change of the Critical Zone over 10 Great Lake Basins across one of the AAC, the Western Rift Valley Corridor (WRVC), in East Africa between the years 2018 and 2060. This approach provides the foundation for implementing improved regional governance, better encouragement of sustainable development beyond the 2030 United Nations Sustainable Development Goals, and education programs, such as the AAC, that promote socio-ecological resilience through Earth Stewardship Science. The AAC archives a portion of East Africa as the WRVC, a corridor along the western branch of the East African Rift System that highlights twenty heritage nodes, primarily great lakes, mountain ranges, national parks, and biological hotspots. These heritage entities are associated with ca. 12-million-years of evolution and transformation of the East African topography and related African Great Lake (AGL) systems. The thesis defines the study area by delineating AGL basins intersected by the WRVC. Across these basins, land cover change analysis provides a platform for an integrated assessment of the projected health of the corridor region. Existing land cover datasets provide the initial conditions of the study area for 2008 and 2013. Land cover between 2008 and 2013 is cross-tabulated using the Land Cover Module in the Terrset software, followed by the iii delineation of sub-models and driver variable identification. The Multi-Layer Perceptron algorithm provides the transition potentials between tree cover, urban area, cropland, wetland, and open area classes. Change quantification and prediction using Markov Chain analysis are then established for 2018, 2030, and 2060. The model successfully simulated future land cover change and concluded that: (1) proximity to existing human activity, proximity to existing tree cover, and population are the primary drivers of change; (2) the dominant land cover of the ten lake basins for 2018 was cropland at ca. 48%, followed by tree cover at ca. 33%; (3) total anthropogenic change over the coming four decades equates to over ca. 52 000 km2 (5 200 000 ha), and particularly (4) an urban area is expected to increase by >130%. This assessment ultimately provides a platform for regional governance development at the basin scale and Earth Stewardship science in East Africa. These changes require transdisciplinary action from researchers to civil society. The AAC provides the foundation for understanding the dynamics of the systems that support life across broader spatial and temporal resolutions in Africa, highlighting the need for future generations to build socio-ecological resilience to anticipate challenges such as biodiversity loss posed by climate change and excessive land cover change. , Thesis (DSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-12
- Authors: Miller, Warren David
- Date: 2022-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/59771 , vital:62423
- Description: Over the coming decades, Africa is expected to experience disturbing effects due to climate change and increased land cover change due to human influences presenting a significant concern for the future well-being of human and biological systems, the latter being the foundation of ecosystem services supplied to humanity. Therefore, unprecedented transdisciplinary cooperation, coordination, and integration amongst researchers, government, and civil society are necessary to increase the resiliency of these systems. This study aims to provide an outline of the Africa Alive Corridors (AAC) as an essential model for the encouragement of sustainable development through Earth Stewardship science. These aims are accompanied by the quantification and forward modelling for land cover change of the Critical Zone over 10 Great Lake Basins across one of the AAC, the Western Rift Valley Corridor (WRVC), in East Africa between the years 2018 and 2060. This approach provides the foundation for implementing improved regional governance, better encouragement of sustainable development beyond the 2030 United Nations Sustainable Development Goals, and education programs, such as the AAC, that promote socio-ecological resilience through Earth Stewardship Science. The AAC archives a portion of East Africa as the WRVC, a corridor along the western branch of the East African Rift System that highlights twenty heritage nodes, primarily great lakes, mountain ranges, national parks, and biological hotspots. These heritage entities are associated with ca. 12-million-years of evolution and transformation of the East African topography and related African Great Lake (AGL) systems. The thesis defines the study area by delineating AGL basins intersected by the WRVC. Across these basins, land cover change analysis provides a platform for an integrated assessment of the projected health of the corridor region. Existing land cover datasets provide the initial conditions of the study area for 2008 and 2013. Land cover between 2008 and 2013 is cross-tabulated using the Land Cover Module in the Terrset software, followed by the iii delineation of sub-models and driver variable identification. The Multi-Layer Perceptron algorithm provides the transition potentials between tree cover, urban area, cropland, wetland, and open area classes. Change quantification and prediction using Markov Chain analysis are then established for 2018, 2030, and 2060. The model successfully simulated future land cover change and concluded that: (1) proximity to existing human activity, proximity to existing tree cover, and population are the primary drivers of change; (2) the dominant land cover of the ten lake basins for 2018 was cropland at ca. 48%, followed by tree cover at ca. 33%; (3) total anthropogenic change over the coming four decades equates to over ca. 52 000 km2 (5 200 000 ha), and particularly (4) an urban area is expected to increase by >130%. This assessment ultimately provides a platform for regional governance development at the basin scale and Earth Stewardship science in East Africa. These changes require transdisciplinary action from researchers to civil society. The AAC provides the foundation for understanding the dynamics of the systems that support life across broader spatial and temporal resolutions in Africa, highlighting the need for future generations to build socio-ecological resilience to anticipate challenges such as biodiversity loss posed by climate change and excessive land cover change. , Thesis (DSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-12
Implementing mathematics intervention strategies to enhance understanding of number sense: an informative framework for the Ekurhuleni North District, Gauteng province, South Africa
- Authors: Hove, Netsai
- Date: 2022-11
- Subjects: Number concept , Mathematics -- Study and teaching
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/26085 , vital:64835
- Description: This study was prompted by the observation that learners’ performance in mathematics is low in South Africa. Several factors such as teachers’ qualifications, demotivated learners, and limited school resources have been raised and considered. Although number sense forms the foundation blocks for mathematics understanding, limited academic work has been done to explore implementable mathematics instructional interventions for the enhancement of understanding number sense. The purpose of this study was to contribute an implementable mathematics intervention framework for understanding number sense. Since the study focused on exploring intervention activities, it was guided by the pragmatism research philosophy. Data were captured from purposive samples of teachers and stratified samples of 1050 learners from schools in the Ekurhuleni North district in South Africa. The research design comprises the following sequence: survey, pre-test, intervention, post-test, and evaluation by teachers’ focus group discussion. These activities were carried out parallel to document analysis, which provided bench marks. The main data-capturing instruments were the questionnaires, learners’ test, interview, and document analysis guides. Factors analysis to establish associations, differences, and regression was carried out using SPSS and Excel. The study found that: almost all teachers implemented some form of mathematics interventions. Continuous assessment was the main intervention, followed by problem-solving, and the use of games (which was least preferred). Teachers shunned games because they require more time and management skills. Challenges that teachers experienced when implementing mathematics interventions include their limited knowledge and the lack of resources and support from education authorities who expect and emphasise high pass rates in mathematics. The teachers’ focus group discussions evaluated the intervention and proposed the following sequence for instructional intervention on number sense: Stage 1: parroting of number names, for example, six, two, nine and seven Stage 2: symbolic identification, for example, the symbol 6, 2, 9 and 7 Stage 3: association where a learner group six stones, shows two fingers, etc. Stage 4: seriating or ordering done through oral counting and use of inequality symbols: () to compare and estimate values in problems Stage 5: the four operations for addition (+), subtraction (-), multiplication (x) and division (÷) emphasizing estimation and application. The study recommends the adoption, modification and implementation of mathematics intervention framework to enhance number sense. , Thesis (MEd) -- Faculty of Education, 2022
- Full Text:
- Date Issued: 2022-11
- Authors: Hove, Netsai
- Date: 2022-11
- Subjects: Number concept , Mathematics -- Study and teaching
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/26085 , vital:64835
- Description: This study was prompted by the observation that learners’ performance in mathematics is low in South Africa. Several factors such as teachers’ qualifications, demotivated learners, and limited school resources have been raised and considered. Although number sense forms the foundation blocks for mathematics understanding, limited academic work has been done to explore implementable mathematics instructional interventions for the enhancement of understanding number sense. The purpose of this study was to contribute an implementable mathematics intervention framework for understanding number sense. Since the study focused on exploring intervention activities, it was guided by the pragmatism research philosophy. Data were captured from purposive samples of teachers and stratified samples of 1050 learners from schools in the Ekurhuleni North district in South Africa. The research design comprises the following sequence: survey, pre-test, intervention, post-test, and evaluation by teachers’ focus group discussion. These activities were carried out parallel to document analysis, which provided bench marks. The main data-capturing instruments were the questionnaires, learners’ test, interview, and document analysis guides. Factors analysis to establish associations, differences, and regression was carried out using SPSS and Excel. The study found that: almost all teachers implemented some form of mathematics interventions. Continuous assessment was the main intervention, followed by problem-solving, and the use of games (which was least preferred). Teachers shunned games because they require more time and management skills. Challenges that teachers experienced when implementing mathematics interventions include their limited knowledge and the lack of resources and support from education authorities who expect and emphasise high pass rates in mathematics. The teachers’ focus group discussions evaluated the intervention and proposed the following sequence for instructional intervention on number sense: Stage 1: parroting of number names, for example, six, two, nine and seven Stage 2: symbolic identification, for example, the symbol 6, 2, 9 and 7 Stage 3: association where a learner group six stones, shows two fingers, etc. Stage 4: seriating or ordering done through oral counting and use of inequality symbols: () to compare and estimate values in problems Stage 5: the four operations for addition (+), subtraction (-), multiplication (x) and division (÷) emphasizing estimation and application. The study recommends the adoption, modification and implementation of mathematics intervention framework to enhance number sense. , Thesis (MEd) -- Faculty of Education, 2022
- Full Text:
- Date Issued: 2022-11
Insights into the drivers and impact of climate change and climate change adaptation in the Eastern Cape, South Africa: the case of Amathole District Municipality
- Authors: Gwala, Lindokuhle
- Date: 2022-11
- Subjects: Climatic changes , Climatic factors , Global environmental change
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27832 , vital:69945
- Description: Climate change is a threat to communal livestock production, causing increases in the rate and intensity of droughts, floods, pests and diseases, and thus subjecting communal livestock production to vulnerability. Communal farmers rely on rain-fed agriculture and are usually too poorly resourced to cope with the frequency of climate-related events that may be expected in the future. Response and adaptation is vital to ensure the sustainability of livestock production, particularly since it is the main source of survival in communal areas. The Eastern Cape Provincial Policy on Climate Change was introduced in 2010 to facilitate a coordinated approach that assists farmers to respond, adapt and mitigate climate change. The study examines the implementation of the policy to identify farmers’ perceptions of the response rate prior to, during and after climate change disasters. In addition, the study establishes the characteristics of livestock production in the study area, seeking to ascertain how communal livestock farmers CLFs are adapting their practices to ensure sustainable livestock production in the face of climate change. In order to make informed decisions on coping strategies, farmers require access to information on climate change. The study therefore examines the communication channels used by farmers to access such information. Since food security is under threat, the study also assesses the effects of climate change on food security among the CLFs. Multi stage sampling was used to select 388 communal livestock farmers in three local municipalities in Amathole District Municipality. A cross-sectional survey was carried out in five communities randomly selected in the three local municipalities, with data collected by means of a semi-structured questionnaire. Descriptive statistics, inferential statistics, principal component analysis and regression methods were used to analyse the data. The study reveals that communal livestock farmers perceive a poor response rate from extension services before, during and after disasters, and that they have poor access to support materials. All of the respondents practised uncontrolled breeding, attributed to a lack of infrastructure such as fencing. Most farmers kept cattle for income generation. The major constraints of cattle production were diseases and pests. CLFs employed dipping, rotational grazing, water tanks, veld burning and the sale of animals as the main strategies to cope with climate change. CLFs access climate change information through multiple channels. The main sources were other farmers and media such as radio and television, although language barriers hampered full understanding of information conveyed about climate chnage. Farmer-to-farmer contact was a central aspect of the CLFs’ lives that could be better employed in the dissemination of climate change information. The results suggest a positive relationship between diversity of species kept and food security. Assets, the social safety net (mainly grants) and adaptive capacity indicators positively and significantly impacted households’ resilience to food insecurity. The study recommends that the capacity of communal livestock farmers on effective mitigating strategies be improved, making use of mass media; that more work be done by extension services to prepare farmers for adverse events and that relief materials disseminated during periods of disaster be tagged “national emergency” to speed up distribution and use. There is an urgent need for adequate and timely provision of climate change information that will help CLFs to make more effective use of their resources in the face of climate change. Agricultural extension services should address challenges associated with breeding practices, disaster response and adult illiteracy to promote better adaptive capacity and ensure food security among this vulnerable cohort. , Thesis (MSci) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-11
- Authors: Gwala, Lindokuhle
- Date: 2022-11
- Subjects: Climatic changes , Climatic factors , Global environmental change
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27832 , vital:69945
- Description: Climate change is a threat to communal livestock production, causing increases in the rate and intensity of droughts, floods, pests and diseases, and thus subjecting communal livestock production to vulnerability. Communal farmers rely on rain-fed agriculture and are usually too poorly resourced to cope with the frequency of climate-related events that may be expected in the future. Response and adaptation is vital to ensure the sustainability of livestock production, particularly since it is the main source of survival in communal areas. The Eastern Cape Provincial Policy on Climate Change was introduced in 2010 to facilitate a coordinated approach that assists farmers to respond, adapt and mitigate climate change. The study examines the implementation of the policy to identify farmers’ perceptions of the response rate prior to, during and after climate change disasters. In addition, the study establishes the characteristics of livestock production in the study area, seeking to ascertain how communal livestock farmers CLFs are adapting their practices to ensure sustainable livestock production in the face of climate change. In order to make informed decisions on coping strategies, farmers require access to information on climate change. The study therefore examines the communication channels used by farmers to access such information. Since food security is under threat, the study also assesses the effects of climate change on food security among the CLFs. Multi stage sampling was used to select 388 communal livestock farmers in three local municipalities in Amathole District Municipality. A cross-sectional survey was carried out in five communities randomly selected in the three local municipalities, with data collected by means of a semi-structured questionnaire. Descriptive statistics, inferential statistics, principal component analysis and regression methods were used to analyse the data. The study reveals that communal livestock farmers perceive a poor response rate from extension services before, during and after disasters, and that they have poor access to support materials. All of the respondents practised uncontrolled breeding, attributed to a lack of infrastructure such as fencing. Most farmers kept cattle for income generation. The major constraints of cattle production were diseases and pests. CLFs employed dipping, rotational grazing, water tanks, veld burning and the sale of animals as the main strategies to cope with climate change. CLFs access climate change information through multiple channels. The main sources were other farmers and media such as radio and television, although language barriers hampered full understanding of information conveyed about climate chnage. Farmer-to-farmer contact was a central aspect of the CLFs’ lives that could be better employed in the dissemination of climate change information. The results suggest a positive relationship between diversity of species kept and food security. Assets, the social safety net (mainly grants) and adaptive capacity indicators positively and significantly impacted households’ resilience to food insecurity. The study recommends that the capacity of communal livestock farmers on effective mitigating strategies be improved, making use of mass media; that more work be done by extension services to prepare farmers for adverse events and that relief materials disseminated during periods of disaster be tagged “national emergency” to speed up distribution and use. There is an urgent need for adequate and timely provision of climate change information that will help CLFs to make more effective use of their resources in the face of climate change. Agricultural extension services should address challenges associated with breeding practices, disaster response and adult illiteracy to promote better adaptive capacity and ensure food security among this vulnerable cohort. , Thesis (MSci) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-11
'ORPHEIOI HYMNOI' The generic contexts of the Orphic Hymns
- Malamis, Daniel Scott Christos
- Authors: Malamis, Daniel Scott Christos
- Date: 2022-10-14
- Subjects: Orphic hymns , Poetics Early works to 1800 , Hymns, Greek (Classical) History and criticism , Literary form
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327177 , vital:61088 , DOI 10.21504/10962/327177
- Description: Uncertainty surrounds the circumstances of Orphic Hymns’ composition and their intended use. Their author has substituted their own identity for that of the mythological poet and there is no certain reference to the extant collection in any ancient source. They are, in this sense, decontextualised. This study aims to make a contribution to the ongoing debate concerning the hymns’ composition, and the original function they might have served, through an analysis of their poetic and generic contexts. Following a detailed survey of scholarship on the hymns, I reflect first on the collection as a unified text, the constitutive parts of the individual hymns and the methods they employ for addressing, describing and praying to the gods. I then study a select group of stylistic features that the hymns prominently display: their use of phonic effects, including etymological figures, of antithesis and symmetrical patterning, and their extensive repetition of poetic formulae. In each case I discuss the deployment and significance of these poetic elements within the collection and consider the intertextual parallels suggested by their recurrence in Greek literary texts of all periods. This analysis reveals the hymns’ engagement with an overlapping set of poetic traditions, including, most prominently, cultic hymns and oracles, gnomic poetry, the theological discourses of the Presocratic philosophers and, in particular, Orphic poetry in its many forms. It suggests moreover that the hymns engage deeply with the oral strategies of the earliest Greek poets, underscoring the conclusion reached by several recent scholars, that the extant collection is essentially performative and was intended to be recited and heard. I argue that the Orphic Hymns were not a unique text in their employment of the stylistic features studied here, but drew extensively upon earlier hymns composed in Orpheus’ name. I further consider, in the light of this argument, the bearing this study has on the unresolved questions of the hymns’ composition, whether by a single author or many, and the aims of the poet(s) who composed them. , Thesis (PhD) -- Faculty of Humanities, School of Languages and Literature Studies, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Malamis, Daniel Scott Christos
- Date: 2022-10-14
- Subjects: Orphic hymns , Poetics Early works to 1800 , Hymns, Greek (Classical) History and criticism , Literary form
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327177 , vital:61088 , DOI 10.21504/10962/327177
- Description: Uncertainty surrounds the circumstances of Orphic Hymns’ composition and their intended use. Their author has substituted their own identity for that of the mythological poet and there is no certain reference to the extant collection in any ancient source. They are, in this sense, decontextualised. This study aims to make a contribution to the ongoing debate concerning the hymns’ composition, and the original function they might have served, through an analysis of their poetic and generic contexts. Following a detailed survey of scholarship on the hymns, I reflect first on the collection as a unified text, the constitutive parts of the individual hymns and the methods they employ for addressing, describing and praying to the gods. I then study a select group of stylistic features that the hymns prominently display: their use of phonic effects, including etymological figures, of antithesis and symmetrical patterning, and their extensive repetition of poetic formulae. In each case I discuss the deployment and significance of these poetic elements within the collection and consider the intertextual parallels suggested by their recurrence in Greek literary texts of all periods. This analysis reveals the hymns’ engagement with an overlapping set of poetic traditions, including, most prominently, cultic hymns and oracles, gnomic poetry, the theological discourses of the Presocratic philosophers and, in particular, Orphic poetry in its many forms. It suggests moreover that the hymns engage deeply with the oral strategies of the earliest Greek poets, underscoring the conclusion reached by several recent scholars, that the extant collection is essentially performative and was intended to be recited and heard. I argue that the Orphic Hymns were not a unique text in their employment of the stylistic features studied here, but drew extensively upon earlier hymns composed in Orpheus’ name. I further consider, in the light of this argument, the bearing this study has on the unresolved questions of the hymns’ composition, whether by a single author or many, and the aims of the poet(s) who composed them. , Thesis (PhD) -- Faculty of Humanities, School of Languages and Literature Studies, 2022
- Full Text:
- Date Issued: 2022-10-14
A critical analysis of the Urban Food System, Urban Governance and Household Food Security in Bulawayo, Zimbabwe
- Authors: Maphosa, Mandlenkosi
- Date: 2022-10-14
- Subjects: Food security Zimbabwe Bulawayo , City planning Government policy Zimbabwe Bulawayo , Urban poor Zimbabwe Bulawayo , Urban agriculture Zimbabwe Bulawayo , COVID-19 (Disease) Zimbabwe Bulawayo , Agent (Philosophy)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327165 , vital:61087 , DOI 10.21504/10962/327165
- Description: Urbanisation is occurring on a massive scale globally and even more so in the less developed regions of the Global South including sub-Saharan Africa (SSA). Like other developing regions of the world, urbanisation in SSA is not occurring alongside a corresponding growth in urban economies. Resultantly, it is taking place in tandem with the rising scourge of urban poverty, including food insecurity. While urban food insecurity is a clear challenge in SSA, the challenge has however not been met with equal vigour in policy making and implementation circles and even in academia. Problematically, the urban food security literature often focuses on one element of the food system without giving due attention to other components of the system. Resultantly, broader systemic failures and the dynamics related to the different actors across the system-elements are missed. There has thus been recent calls to embrace urban governance in studying urban food systems, which this study does. The thesis examines the urban food system in Bulawayo (in Zimbabwe) with specific reference to urban governance and household food security to understand sociologically the complex multi-dimensional processes, structures, systems, and practices underpinning the urban food system. As a result of the complex nature of food systems, an eclectic analytical framework is employed encompassing Obeng Odoom’s DED framework, Clapp and Fuchs’ framework of power, Gaventa’s power cube and theories of everyday life derived from de Certeau and Lefebvre. Methodologically, the study is informed by a Critical Realism paradigm which accommodates the convergent mixed methods research design employed. The research strategy employed was that of a survey and case study. Key findings reveal that the Bulawayo food system, from production to consumption, is complex and is nested within broader national and international food systems. Although without a direct and explicit mandate on food security, the local authority is at the centre of urban governance processes as it employs a plethora of strategies to influence the nature of the food system. However, the study reveals that the food system is as much a construction from below through the agential activities of the urban poor. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Maphosa, Mandlenkosi
- Date: 2022-10-14
- Subjects: Food security Zimbabwe Bulawayo , City planning Government policy Zimbabwe Bulawayo , Urban poor Zimbabwe Bulawayo , Urban agriculture Zimbabwe Bulawayo , COVID-19 (Disease) Zimbabwe Bulawayo , Agent (Philosophy)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327165 , vital:61087 , DOI 10.21504/10962/327165
- Description: Urbanisation is occurring on a massive scale globally and even more so in the less developed regions of the Global South including sub-Saharan Africa (SSA). Like other developing regions of the world, urbanisation in SSA is not occurring alongside a corresponding growth in urban economies. Resultantly, it is taking place in tandem with the rising scourge of urban poverty, including food insecurity. While urban food insecurity is a clear challenge in SSA, the challenge has however not been met with equal vigour in policy making and implementation circles and even in academia. Problematically, the urban food security literature often focuses on one element of the food system without giving due attention to other components of the system. Resultantly, broader systemic failures and the dynamics related to the different actors across the system-elements are missed. There has thus been recent calls to embrace urban governance in studying urban food systems, which this study does. The thesis examines the urban food system in Bulawayo (in Zimbabwe) with specific reference to urban governance and household food security to understand sociologically the complex multi-dimensional processes, structures, systems, and practices underpinning the urban food system. As a result of the complex nature of food systems, an eclectic analytical framework is employed encompassing Obeng Odoom’s DED framework, Clapp and Fuchs’ framework of power, Gaventa’s power cube and theories of everyday life derived from de Certeau and Lefebvre. Methodologically, the study is informed by a Critical Realism paradigm which accommodates the convergent mixed methods research design employed. The research strategy employed was that of a survey and case study. Key findings reveal that the Bulawayo food system, from production to consumption, is complex and is nested within broader national and international food systems. Although without a direct and explicit mandate on food security, the local authority is at the centre of urban governance processes as it employs a plethora of strategies to influence the nature of the food system. However, the study reveals that the food system is as much a construction from below through the agential activities of the urban poor. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Date Issued: 2022-10-14
A social history of midwifery practices in colonial Ibadan, Nigeria, 1893 - 1960
- Olorunnibe, Folaranmi Flourish
- Authors: Olorunnibe, Folaranmi Flourish
- Date: 2022-10-14
- Subjects: Midwifery Nigeria Ibadan , Nigeria History 1900-1960 , Nigeria Politics and government To 1960 , Nigeria Social conditions To 1960 , Maternal health services Nigeria Ibadan , Ibadan (Nigeria) Colonial influence
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/408716 , vital:70519 , DOI 10.21504/10962/408716
- Description: This thesis examines the introduction and development of western medical practices in colonial spaces with particular reference to midwifery practices in colonial Ibadan, Nigeria, from 1893 to 1960. This has become necessary because of the importance placed on childbirth and maternal healthcare in the twentieth century. The trends and changes in midwifery and midwifery practices in colonial Ibadan are seen as reflections of other transformations in British African colonies at large. The study begins with a detailed historical analysis of the major metropolitan and local factors that informed the introduction and development of Western obstetrics in colonial Ibadan, Nigeria. It proceeds to examine the development of Western midwifery practices in colonial Ibadan; highlighting the contributions of the Ibadan people to the development of Western midwifery practices and emphasizing policies affecting development, and implementation of Western obstetrics. The thesis goes further to reveal the prejudiced nature of colonial medical policies, and the ways it shaped various responses especially from rural folks who were particularly marginalized since the 1920s when maternal healthcare policies was implemented in the urban areas till the 1950s when a reformed policy for rural medical service scheme was introduced to the rural folks. Thus, influencing the ways they imagined and appropriated ideas of western obstetrics alongside African traditional midwifery practices. The idea is to demonstrate in this thesis the extent to which the precincts in colonial medical policies, most especially the establishment of maternity hospitals, clinics and dispensaries, and the institutionalization of western obstetrics, inspired critical and ingenious responses from colonial doctors, colonial officials, the missionaries, patients, African trained midwives, traditional medical practitioners and the African population in general. Placing all of these historical events within a wider context, this thesis borrows insights from the social history of medicine in an attempt to reconstruct the colonial medical practices in Ibadan, Nigeria, through the sites of midwifery practices and maternal welfare services from 1893 to 1960. This is in addition to its dependence on a comparatively rich, but skewed historical evidence, including a plethora of annual medical reports, official reports of the department of medical and sanitary services, official correspondences within the colonial government in Ibadan and Nigeria, and between the colonial government and the colonial office in the United Kingdom. Details of African responses to medical policies were garnered from oral testimonies, newspaper publications and correspondences between the African public and the colonial government in Ibadan. In exploring this historical evidence, the thesis reveals very interesting details of colonial perceptions about African health and their underlining motives for introducing western medical ideas, the various medical schemes and policies used in driving colonial interest and the ways Africans imagined, re-imagined, and appropriated Western medical practices. , Thesis (PhD) -- Faculty of Humanities, History, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Olorunnibe, Folaranmi Flourish
- Date: 2022-10-14
- Subjects: Midwifery Nigeria Ibadan , Nigeria History 1900-1960 , Nigeria Politics and government To 1960 , Nigeria Social conditions To 1960 , Maternal health services Nigeria Ibadan , Ibadan (Nigeria) Colonial influence
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/408716 , vital:70519 , DOI 10.21504/10962/408716
- Description: This thesis examines the introduction and development of western medical practices in colonial spaces with particular reference to midwifery practices in colonial Ibadan, Nigeria, from 1893 to 1960. This has become necessary because of the importance placed on childbirth and maternal healthcare in the twentieth century. The trends and changes in midwifery and midwifery practices in colonial Ibadan are seen as reflections of other transformations in British African colonies at large. The study begins with a detailed historical analysis of the major metropolitan and local factors that informed the introduction and development of Western obstetrics in colonial Ibadan, Nigeria. It proceeds to examine the development of Western midwifery practices in colonial Ibadan; highlighting the contributions of the Ibadan people to the development of Western midwifery practices and emphasizing policies affecting development, and implementation of Western obstetrics. The thesis goes further to reveal the prejudiced nature of colonial medical policies, and the ways it shaped various responses especially from rural folks who were particularly marginalized since the 1920s when maternal healthcare policies was implemented in the urban areas till the 1950s when a reformed policy for rural medical service scheme was introduced to the rural folks. Thus, influencing the ways they imagined and appropriated ideas of western obstetrics alongside African traditional midwifery practices. The idea is to demonstrate in this thesis the extent to which the precincts in colonial medical policies, most especially the establishment of maternity hospitals, clinics and dispensaries, and the institutionalization of western obstetrics, inspired critical and ingenious responses from colonial doctors, colonial officials, the missionaries, patients, African trained midwives, traditional medical practitioners and the African population in general. Placing all of these historical events within a wider context, this thesis borrows insights from the social history of medicine in an attempt to reconstruct the colonial medical practices in Ibadan, Nigeria, through the sites of midwifery practices and maternal welfare services from 1893 to 1960. This is in addition to its dependence on a comparatively rich, but skewed historical evidence, including a plethora of annual medical reports, official reports of the department of medical and sanitary services, official correspondences within the colonial government in Ibadan and Nigeria, and between the colonial government and the colonial office in the United Kingdom. Details of African responses to medical policies were garnered from oral testimonies, newspaper publications and correspondences between the African public and the colonial government in Ibadan. In exploring this historical evidence, the thesis reveals very interesting details of colonial perceptions about African health and their underlining motives for introducing western medical ideas, the various medical schemes and policies used in driving colonial interest and the ways Africans imagined, re-imagined, and appropriated Western medical practices. , Thesis (PhD) -- Faculty of Humanities, History, 2022
- Full Text:
- Date Issued: 2022-10-14
A sociological analysis of the experiences of Zimbabwean teachers in South Africa: the case of KwaZulu-Natal townships and township secondary schools
- Authors: Daki, Andile Lebohang
- Date: 2022-10-14
- Subjects: Xenophobia South Africa KwaZulu-Natal , Teachers, Foreign South Africa KwaZulu-Natal , Zimbabweans South Africa KwaZulu-Natal , Teachers, Foreign Social conditions , Marginality, Social , Culture conflict South Africa KwaZulu-Natal
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365953 , vital:65805 , DOI https://doi.org/10.21504/10962/365953
- Description: This thesis seeks to understand the social and cultural experiences of Zimbabwean teachers, as foreigners, in KwaZulu-Natal townships, and KwaZulu-Natal township secondary schools, in South Africa. It examines the ways in which Zimbabwean teachers negotiate the social, cultural, and institutional milieu of KwaZulu-Natal townships and secondary schools. In doing so, the thesis draws upon social interface theory, as this theory facilitates an examination and understanding of the ways in which the Zimbabwean teachers interpret the spaces (and lifeworld) of South Africans and, simultaneously, navigate their way in and through these spaces along social and cultural interfaces. While the focus is on the perspectives and practices of the Zimbabwean teachers, the thesis recognises and shows that their socio-cultural experiences are constituted and configured in significant ways by their daily encounters with South Africans. The fieldwork for the thesis involved primarily in-depth interviews with thirty Zimbabwean teachers residing in six selected KwaZulu-Natal townships (and teaching at six different secondary schools), as well as fifteen South African teachers, five school administrators and thirty other South African citizens. The sample of Zimbabwean teachers was stratified in relation to the different townships, as well as gender and the number of years teaching in South Africa, so as to investigate whether and how these variables may configure the socio-cultural experiences of these teachers. A consideration of variation in the number of years of teaching in South Africa in particular allowed for an examination of possible shifts in socio-cultural experiences over time, as negotiation along interfaces is an ongoing and contingent process. The findings demonstrate a range of experiences and challenges faced by Zimbabwean teachers in KwaZulu-Natal (with regard to both township and school life), some of which they share with South African teachers but many of which are unique to them. At the same time, there are important differences amongst Zimbabwean teachers in relation to how they interface with South African citizens and teachers. While some teachers negotiate local spaces through active socialising and assimilating into the lifeworld (township life of South Africans and the institutional culture of township schools), other teachers move through the space by way of isolation, withdrawal, and alienation. In general, in terms of adjusting to the lifeworld of South Africans in KwaZulu-Natal townships and schools, Zimbabwean teachers pursue different routes which, in the end, made sense to them and about which they express some degree of personal comfort. , Lo mbhalo wobuhlakani uzama ukuqonda inhlalo kanye namasiko abahlangabezana nako othisha baseZimbabwe njengabantu bokufika emalokishini akwaZulu-Natal, kanye nasezikoleni zamabanga athe thuthu zasemalokishini akwaZulu-Natal eNingizimu-Afrika. Uhlolisisa izindlela labo thisha ababonisana ngazo ngamasiko kanye nenhlalakahle yasezikoleni zasemalokishini akwaZulu-Natal. Ngokwenzanjalo, lo mbhalo udonsa umhlahlandlela wenhlalakahle nokuhlangana ngoba ukungena kwabo endaweni yakwaZulu-Natal, labo thisha bahumusha indawo baphinde babonisane bachushisane ngenqubekela phambili yabo nangenhlalo namasiko abahlangabezana nawo. Ukuhlanganisa othisha baseNingizimu-Afrika nezakhamuzi kumele kusebenzisane ngokulingana. Abahlangabezana nakho kwakhiwa ngokubambisana phakathi kwabaseZimbabwe kanye nabaseNingizimu-Afrika ukuze izwi labaseNingizimu-Afrika lingagqibeki ngoba sekunakekelwa kakhulu abseZimbabwe. Umsebenzi wasensimini walo mbhalo wobuhlakani uhlanganisa ucwaningo kothisha abangani-30 baseZimbabwe abahlala ezindaweni ezingu-6 ezikhethekile ezisemalokishini akwaZulu-Natal, nothisha abayi-15 baseNingizimu-Afrika kanye nabaphathi bezikole abayi-5. Kubuye kwenziwa ucwaningo kwizakhamuzi ezingama-30 zaseNingizimu-Afrika. Isampula lihlanganiswe ngokubuka indawo lapho aphuma khona umuntu, kanye neminyaka aseyifundisile eNingizimu-Afrika. Ucwaningo lubukisise kakhulu indlela ababuka ngayo inhlalakahle namasiko kube kubukisiswa nenani leminyaka aseyifundisile umuntu ngamunye ukuze kuhlolisiswe izinguquko zokuxoxisana ezidalwe yisikhathi asihlalile umuntu phakathi kothisha abasebancane nalabo asebekhulile. Imiphumela yocwaningo iveza iznselele ezahlukene ababhekene nazo othisha baseZimbabwe njengoba bengabahlali baseNingizimu-Afrika. Ezinye zalezi nselele ziqhamuka ngokwehlukana kwemiphakathi kwabaseZimbabwe kanye nabaseNingizimu-Afrika. Ngokunjalo kunomehluko obalulekayo kothisha baseZimbabwe mayelana nendlela ukuxoxisana nokubonisana okuqhubeka ngayo. Kukhona labo ukungena bathi khaxa emiphakathini nasezimpilweni abakuzo eNingizimu-Afrika nasezikoleni abakuzo namasiko nenhlalakahle yakulezo zindawo ngakolunye uhlangothi abanye othisha bazithole bephila njengenhlwa bephila ngabodwana eNingizimu-Afrika. Kodwa ekugcineni kwakho konke, lolu cwaningo luthola ukuthi othisha baseZimbabwe ezikoleni zasemalokishini akwaZulu-Natal lapha eNingizimu-Afrika bazakhela impilo eyenza umuntu ngamunye azizwe ehlaliseke kahle eNingizimu- Afrika ngendlela ephelele nethokomalisa yena ngo kwakhe. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Daki, Andile Lebohang
- Date: 2022-10-14
- Subjects: Xenophobia South Africa KwaZulu-Natal , Teachers, Foreign South Africa KwaZulu-Natal , Zimbabweans South Africa KwaZulu-Natal , Teachers, Foreign Social conditions , Marginality, Social , Culture conflict South Africa KwaZulu-Natal
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365953 , vital:65805 , DOI https://doi.org/10.21504/10962/365953
- Description: This thesis seeks to understand the social and cultural experiences of Zimbabwean teachers, as foreigners, in KwaZulu-Natal townships, and KwaZulu-Natal township secondary schools, in South Africa. It examines the ways in which Zimbabwean teachers negotiate the social, cultural, and institutional milieu of KwaZulu-Natal townships and secondary schools. In doing so, the thesis draws upon social interface theory, as this theory facilitates an examination and understanding of the ways in which the Zimbabwean teachers interpret the spaces (and lifeworld) of South Africans and, simultaneously, navigate their way in and through these spaces along social and cultural interfaces. While the focus is on the perspectives and practices of the Zimbabwean teachers, the thesis recognises and shows that their socio-cultural experiences are constituted and configured in significant ways by their daily encounters with South Africans. The fieldwork for the thesis involved primarily in-depth interviews with thirty Zimbabwean teachers residing in six selected KwaZulu-Natal townships (and teaching at six different secondary schools), as well as fifteen South African teachers, five school administrators and thirty other South African citizens. The sample of Zimbabwean teachers was stratified in relation to the different townships, as well as gender and the number of years teaching in South Africa, so as to investigate whether and how these variables may configure the socio-cultural experiences of these teachers. A consideration of variation in the number of years of teaching in South Africa in particular allowed for an examination of possible shifts in socio-cultural experiences over time, as negotiation along interfaces is an ongoing and contingent process. The findings demonstrate a range of experiences and challenges faced by Zimbabwean teachers in KwaZulu-Natal (with regard to both township and school life), some of which they share with South African teachers but many of which are unique to them. At the same time, there are important differences amongst Zimbabwean teachers in relation to how they interface with South African citizens and teachers. While some teachers negotiate local spaces through active socialising and assimilating into the lifeworld (township life of South Africans and the institutional culture of township schools), other teachers move through the space by way of isolation, withdrawal, and alienation. In general, in terms of adjusting to the lifeworld of South Africans in KwaZulu-Natal townships and schools, Zimbabwean teachers pursue different routes which, in the end, made sense to them and about which they express some degree of personal comfort. , Lo mbhalo wobuhlakani uzama ukuqonda inhlalo kanye namasiko abahlangabezana nako othisha baseZimbabwe njengabantu bokufika emalokishini akwaZulu-Natal, kanye nasezikoleni zamabanga athe thuthu zasemalokishini akwaZulu-Natal eNingizimu-Afrika. Uhlolisisa izindlela labo thisha ababonisana ngazo ngamasiko kanye nenhlalakahle yasezikoleni zasemalokishini akwaZulu-Natal. Ngokwenzanjalo, lo mbhalo udonsa umhlahlandlela wenhlalakahle nokuhlangana ngoba ukungena kwabo endaweni yakwaZulu-Natal, labo thisha bahumusha indawo baphinde babonisane bachushisane ngenqubekela phambili yabo nangenhlalo namasiko abahlangabezana nawo. Ukuhlanganisa othisha baseNingizimu-Afrika nezakhamuzi kumele kusebenzisane ngokulingana. Abahlangabezana nakho kwakhiwa ngokubambisana phakathi kwabaseZimbabwe kanye nabaseNingizimu-Afrika ukuze izwi labaseNingizimu-Afrika lingagqibeki ngoba sekunakekelwa kakhulu abseZimbabwe. Umsebenzi wasensimini walo mbhalo wobuhlakani uhlanganisa ucwaningo kothisha abangani-30 baseZimbabwe abahlala ezindaweni ezingu-6 ezikhethekile ezisemalokishini akwaZulu-Natal, nothisha abayi-15 baseNingizimu-Afrika kanye nabaphathi bezikole abayi-5. Kubuye kwenziwa ucwaningo kwizakhamuzi ezingama-30 zaseNingizimu-Afrika. Isampula lihlanganiswe ngokubuka indawo lapho aphuma khona umuntu, kanye neminyaka aseyifundisile eNingizimu-Afrika. Ucwaningo lubukisise kakhulu indlela ababuka ngayo inhlalakahle namasiko kube kubukisiswa nenani leminyaka aseyifundisile umuntu ngamunye ukuze kuhlolisiswe izinguquko zokuxoxisana ezidalwe yisikhathi asihlalile umuntu phakathi kothisha abasebancane nalabo asebekhulile. Imiphumela yocwaningo iveza iznselele ezahlukene ababhekene nazo othisha baseZimbabwe njengoba bengabahlali baseNingizimu-Afrika. Ezinye zalezi nselele ziqhamuka ngokwehlukana kwemiphakathi kwabaseZimbabwe kanye nabaseNingizimu-Afrika. Ngokunjalo kunomehluko obalulekayo kothisha baseZimbabwe mayelana nendlela ukuxoxisana nokubonisana okuqhubeka ngayo. Kukhona labo ukungena bathi khaxa emiphakathini nasezimpilweni abakuzo eNingizimu-Afrika nasezikoleni abakuzo namasiko nenhlalakahle yakulezo zindawo ngakolunye uhlangothi abanye othisha bazithole bephila njengenhlwa bephila ngabodwana eNingizimu-Afrika. Kodwa ekugcineni kwakho konke, lolu cwaningo luthola ukuthi othisha baseZimbabwe ezikoleni zasemalokishini akwaZulu-Natal lapha eNingizimu-Afrika bazakhela impilo eyenza umuntu ngamunye azizwe ehlaliseke kahle eNingizimu- Afrika ngendlela ephelele nethokomalisa yena ngo kwakhe. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Date Issued: 2022-10-14
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:
- Date Issued: 2022-10-14
- 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:
- Date Issued: 2022-10-14
Bioinformatics tool and web server development focusing on structural bioinformatics applications
- Authors: Nabatanzi, Margaret
- Date: 2022-10-14
- Subjects: Structural bioinformatics , Proteins Structure , Protein structure prediction , Proteins Conformation , Protein complex
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365700 , vital:65777 , DOI https://doi.org/10.21504/10962/365700
- Description: This thesis is divided into two main sections: Part 1 describes the design, and evaluation of the accuracy of a new web server – PRotein Interactive MOdeling (PRIMO-Complexes) for modeling protein complexes and biological assemblies. The second part describes the development of bioinformatics tools to predict HIV-1 drug resistance and support bioinformatics research and education. Recent technological advances have resulted in a tremendous increase in the number of sequences and protein structures deposited in the Universal Protein Resource Knowledgebase (UniProtKB) and the Protein Data Bank (PDB). However, the number of sequences has increased at a higher rate compared with the experimentally solved multimeric protein structures. This is partly due to advances in high-throughput sequencing technology. To fill this protein sequence-structure gap, computational approaches have been developed to predict protein structures from available sequences. Computational approaches include template-based and ab initio modeling with the former being the most reliable. Template-based modeling process can be achieved using either standalone software or automated modeling web servers. However, using standalone software requires familiarity with command-line interfaces as well as utilising other intermediate programs which could be daunting to novice users. To alleviate some of these problems, the modeling process has been automated, however, it still has numerous challenges. To date, only a few web servers that support multimeric protein modeling have been developed and even these provide little, if any user involvement in the process. To address some of these issues, a new web server – PRIMO-Complexes – was developed to model protein complexes and biological assemblies. The existing PRIMO web server could only model monomeric proteins. Part 1 of this thesis provides a detailed account of the development and evaluation of PRIMO-Complexes. The rationale for developing this new web server was based on the understanding that most proteins function as protein multimers and often the ligand-binding sites, and enzyme active sites are located at the protein-protein interfaces. It, therefore, necessitated developing capabilities for modeling multimeric proteins. PRIMO-Complexes web server was developed using the Waterfall system development life cycle model, is based on the Django web framework and makes use of high-performance computing resources to execute jobs. The accuracy of the algorithms embedded in PRIMO- Complexes was evaluated and the results were promising. Additionally, PRIMO-Complexes performs comparatively well in relation to other web servers that offer multimeric protein modeling. Another unique feature of PRIMO-Complexes is its interactivity. The webserver was developed with capabilities for allowing users to model multimeric proteins with an appreciable degree of control over the process. In the second part of the thesis several other bioinformatics tools are described, for example, a webserver for predicting HIV-1 drug resistance, the RUBi protein model repository, and a bioinformatics web portal for education and research resources. RUBi protein model repository stores verified theoretical models built using various modeling approaches. This enables users to easily access models to reproduce and/or further the research. This is described in chapter 5. Chapter 6 describes the design and development of the Human Immunodeficiency type 1 Resistance Predictor (HIV-1 ResPredictor), a web application that employs artificial neural networks (ANN) to predict drug resistance in patients infected with HIV-1 subtype B. The ANNs and subtype classifiers performed well making this web application potentially useful to both clinicians and researchers in this era of personalised medicine. Finally, chapter 7 describes a bioinformatics education web portal that equips students with information on how to use bioinformatics online resources. Being aware of these resources is not enough without a deeper understanding and guidance on how to apply bioinformatics methods to solve practical problems. This web portal was aimed at familiarising students with the basic terminology and approaches in structural bioinformatics. Students will potentially gain skills to conduct real-life bioinformatics research to obtain biological insights. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Nabatanzi, Margaret
- Date: 2022-10-14
- Subjects: Structural bioinformatics , Proteins Structure , Protein structure prediction , Proteins Conformation , Protein complex
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365700 , vital:65777 , DOI https://doi.org/10.21504/10962/365700
- Description: This thesis is divided into two main sections: Part 1 describes the design, and evaluation of the accuracy of a new web server – PRotein Interactive MOdeling (PRIMO-Complexes) for modeling protein complexes and biological assemblies. The second part describes the development of bioinformatics tools to predict HIV-1 drug resistance and support bioinformatics research and education. Recent technological advances have resulted in a tremendous increase in the number of sequences and protein structures deposited in the Universal Protein Resource Knowledgebase (UniProtKB) and the Protein Data Bank (PDB). However, the number of sequences has increased at a higher rate compared with the experimentally solved multimeric protein structures. This is partly due to advances in high-throughput sequencing technology. To fill this protein sequence-structure gap, computational approaches have been developed to predict protein structures from available sequences. Computational approaches include template-based and ab initio modeling with the former being the most reliable. Template-based modeling process can be achieved using either standalone software or automated modeling web servers. However, using standalone software requires familiarity with command-line interfaces as well as utilising other intermediate programs which could be daunting to novice users. To alleviate some of these problems, the modeling process has been automated, however, it still has numerous challenges. To date, only a few web servers that support multimeric protein modeling have been developed and even these provide little, if any user involvement in the process. To address some of these issues, a new web server – PRIMO-Complexes – was developed to model protein complexes and biological assemblies. The existing PRIMO web server could only model monomeric proteins. Part 1 of this thesis provides a detailed account of the development and evaluation of PRIMO-Complexes. The rationale for developing this new web server was based on the understanding that most proteins function as protein multimers and often the ligand-binding sites, and enzyme active sites are located at the protein-protein interfaces. It, therefore, necessitated developing capabilities for modeling multimeric proteins. PRIMO-Complexes web server was developed using the Waterfall system development life cycle model, is based on the Django web framework and makes use of high-performance computing resources to execute jobs. The accuracy of the algorithms embedded in PRIMO- Complexes was evaluated and the results were promising. Additionally, PRIMO-Complexes performs comparatively well in relation to other web servers that offer multimeric protein modeling. Another unique feature of PRIMO-Complexes is its interactivity. The webserver was developed with capabilities for allowing users to model multimeric proteins with an appreciable degree of control over the process. In the second part of the thesis several other bioinformatics tools are described, for example, a webserver for predicting HIV-1 drug resistance, the RUBi protein model repository, and a bioinformatics web portal for education and research resources. RUBi protein model repository stores verified theoretical models built using various modeling approaches. This enables users to easily access models to reproduce and/or further the research. This is described in chapter 5. Chapter 6 describes the design and development of the Human Immunodeficiency type 1 Resistance Predictor (HIV-1 ResPredictor), a web application that employs artificial neural networks (ANN) to predict drug resistance in patients infected with HIV-1 subtype B. The ANNs and subtype classifiers performed well making this web application potentially useful to both clinicians and researchers in this era of personalised medicine. Finally, chapter 7 describes a bioinformatics education web portal that equips students with information on how to use bioinformatics online resources. Being aware of these resources is not enough without a deeper understanding and guidance on how to apply bioinformatics methods to solve practical problems. This web portal was aimed at familiarising students with the basic terminology and approaches in structural bioinformatics. Students will potentially gain skills to conduct real-life bioinformatics research to obtain biological insights. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Cape Fold Ecoregion fish community ecology and responses to stressors
- Authors: Broom, Casey Jay
- Date: 2022-10-14
- Subjects: Cyprinidae South Africa Western Cape , Freshwater fishes South Africa Western Cape , Cyprinidae Habitat South Africa Western Cape , Food chains (Ecology) , Restoration ecology South Africa Western Cape , Riparian restoration South Africa Western Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365644 , vital:65772 , DOI https://doi.org/10.21504/10962/365644
- Description: Freshwater fishes are in global decline and fish as a group are the most imperilled of all vertebrates. Freshwater systems are among the most threatened globally, largely owing to their comparatively high species and habitat diversity while occupying a minute fraction of the Earth’s surface. In South Africa, invasion by non-native fishes has had a devastating effect on freshwater systems across the country. Numerous other stressors and anthropogenic impacts continue to impact these systems, including habitat degradation, water abstraction and global change effects. In general, South African freshwater systems are under-studied and there is a lack of baseline biological and ecological studies on many freshwater fish species. The Cape Fold Ecoregion (CFE) of South Africa is a particularly vulnerable region, with many range-restricted species and highly fragmented native fish ranges following high invasion rates. Within the CFE, the Olifants-Doring River System (ODRS) is of primary concern owing to the high endemism and imperilled status of its freshwater fish species. The Rondegat River in the ODRS is of notable conservation value, as it hosts populations of important endemic CFE species. This river is unique, being the site of the first alien fish eradication programme of its kind in South Africa. Thus the Rondegat River, and in particular its imperilled cyprinid assemblage, is used here as a case study of the responses and community dynamics of recovering freshwater fish species. The members of this cyprinid assemblage are Sedercypris calidus, Pseudobarbus phlegethon and Labeobarbus seeberi. Sedercypris calidus and L. seeberi are listed by the International Union for the Conservation of Nature (IUCN) as “Near-Threatened”, while P. phlegethon is listed as “Endangered”. Understanding the dynamics and responses to understudied vulnerable fish communities in the wake of restoration efforts was the overarching goal of this thesis. The first chapter served as a review of current knowledge of the CFE, the Rondegat River, the myriad stressors that have impacted on or are projected to affect this region, and the freshwater fish species on which those stressors act. My first investigations served as an extension of the existing Rondegat River monitoring programme, making use of remote underwater video (RUV) data to assess relative abundance and habitat associations of the focal species (Chapter 2). A relatively limited spatial range of P. phlegethon was established, which was suggested to be a result of relatively highly specialised habitat requirements and sensitivity to disturbance. Sedercypris calidus was confirmed as a relatively more abundant and ubiquitous species across the length of the Rondegat River, sharing much of the lower and middle reaches with L. seeberi. I sought to use experimental trials of functional response, as a proxy for feeding performance, across representative temperatures and relevant prey types, in the spatially overlapping S. calidus and L. seeberi (Chapter 3). Labeobarbus seeberi generally outcompeted S. calidus across temperature treatments and prey types. The ecomorphology and diet of all three species were used to construct trophic profiles, which suggested that there was a high degree of feeding capacity overlap between L. seeberi and S. calidus, while P. phlegethon diverged from the other two species (Chapter 4). Gut content suggested that all three species overlapped broadly in diet. This indicated that the realised trophic niche of these species is similar, despite some morphological specialisation. I then used RUV data to investigate in-situ feeding behaviours, with the aim to disentangle the nuances of community dynamics and mechanisms of coexistence in the cyprinid assemblage (Chapter 5). I found that, despite the higher feeding performance of L. seeberi (Chapter 3) and its overlaps in diet and feeding capacity with S. calidus (Chapter 4), S. calidus is able to mitigate competitive pressures through foraging mode switching and exploitation of allochthonous food inputs. Evidence for further habitat and prey selectivity in Pseudobarbus phlegethon was gathered based on dependence on complex habitats and pool refugia for the majority of its feeding, supporting this species as a headwater specialist; alongside signals of its spatial and habitat use patterns (Chapter 2). While S. calidus and L. seeberi were found to be less habitat-specific than P. phlegethon, caution was noted in the potential for ongoing stressors, such as habitat destruction, loss of river connectivity and global change effects, to impact on the reproductive success of these two species. Stressors affecting the habitats and sensitive invertebrate taxa upon which all three species depend continue to threaten the Rondegat system, highlighting the need to maintain ecosystem integrity through conservation interventions. There remains significant scope to maintain restoration efforts in the Rondegat River and other river systems of the CFE, through direct conservation actions, enhanced community awareness, indigenous riparian vegetation restoration and involvement of local stakeholders in various conservation-centred activities. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Broom, Casey Jay
- Date: 2022-10-14
- Subjects: Cyprinidae South Africa Western Cape , Freshwater fishes South Africa Western Cape , Cyprinidae Habitat South Africa Western Cape , Food chains (Ecology) , Restoration ecology South Africa Western Cape , Riparian restoration South Africa Western Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365644 , vital:65772 , DOI https://doi.org/10.21504/10962/365644
- Description: Freshwater fishes are in global decline and fish as a group are the most imperilled of all vertebrates. Freshwater systems are among the most threatened globally, largely owing to their comparatively high species and habitat diversity while occupying a minute fraction of the Earth’s surface. In South Africa, invasion by non-native fishes has had a devastating effect on freshwater systems across the country. Numerous other stressors and anthropogenic impacts continue to impact these systems, including habitat degradation, water abstraction and global change effects. In general, South African freshwater systems are under-studied and there is a lack of baseline biological and ecological studies on many freshwater fish species. The Cape Fold Ecoregion (CFE) of South Africa is a particularly vulnerable region, with many range-restricted species and highly fragmented native fish ranges following high invasion rates. Within the CFE, the Olifants-Doring River System (ODRS) is of primary concern owing to the high endemism and imperilled status of its freshwater fish species. The Rondegat River in the ODRS is of notable conservation value, as it hosts populations of important endemic CFE species. This river is unique, being the site of the first alien fish eradication programme of its kind in South Africa. Thus the Rondegat River, and in particular its imperilled cyprinid assemblage, is used here as a case study of the responses and community dynamics of recovering freshwater fish species. The members of this cyprinid assemblage are Sedercypris calidus, Pseudobarbus phlegethon and Labeobarbus seeberi. Sedercypris calidus and L. seeberi are listed by the International Union for the Conservation of Nature (IUCN) as “Near-Threatened”, while P. phlegethon is listed as “Endangered”. Understanding the dynamics and responses to understudied vulnerable fish communities in the wake of restoration efforts was the overarching goal of this thesis. The first chapter served as a review of current knowledge of the CFE, the Rondegat River, the myriad stressors that have impacted on or are projected to affect this region, and the freshwater fish species on which those stressors act. My first investigations served as an extension of the existing Rondegat River monitoring programme, making use of remote underwater video (RUV) data to assess relative abundance and habitat associations of the focal species (Chapter 2). A relatively limited spatial range of P. phlegethon was established, which was suggested to be a result of relatively highly specialised habitat requirements and sensitivity to disturbance. Sedercypris calidus was confirmed as a relatively more abundant and ubiquitous species across the length of the Rondegat River, sharing much of the lower and middle reaches with L. seeberi. I sought to use experimental trials of functional response, as a proxy for feeding performance, across representative temperatures and relevant prey types, in the spatially overlapping S. calidus and L. seeberi (Chapter 3). Labeobarbus seeberi generally outcompeted S. calidus across temperature treatments and prey types. The ecomorphology and diet of all three species were used to construct trophic profiles, which suggested that there was a high degree of feeding capacity overlap between L. seeberi and S. calidus, while P. phlegethon diverged from the other two species (Chapter 4). Gut content suggested that all three species overlapped broadly in diet. This indicated that the realised trophic niche of these species is similar, despite some morphological specialisation. I then used RUV data to investigate in-situ feeding behaviours, with the aim to disentangle the nuances of community dynamics and mechanisms of coexistence in the cyprinid assemblage (Chapter 5). I found that, despite the higher feeding performance of L. seeberi (Chapter 3) and its overlaps in diet and feeding capacity with S. calidus (Chapter 4), S. calidus is able to mitigate competitive pressures through foraging mode switching and exploitation of allochthonous food inputs. Evidence for further habitat and prey selectivity in Pseudobarbus phlegethon was gathered based on dependence on complex habitats and pool refugia for the majority of its feeding, supporting this species as a headwater specialist; alongside signals of its spatial and habitat use patterns (Chapter 2). While S. calidus and L. seeberi were found to be less habitat-specific than P. phlegethon, caution was noted in the potential for ongoing stressors, such as habitat destruction, loss of river connectivity and global change effects, to impact on the reproductive success of these two species. Stressors affecting the habitats and sensitive invertebrate taxa upon which all three species depend continue to threaten the Rondegat system, highlighting the need to maintain ecosystem integrity through conservation interventions. There remains significant scope to maintain restoration efforts in the Rondegat River and other river systems of the CFE, through direct conservation actions, enhanced community awareness, indigenous riparian vegetation restoration and involvement of local stakeholders in various conservation-centred activities. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-10-14
Characterisation of two novel ferrocenyl benzoxazines as in vitro triple-negative breast cancer inhibitors
- Authors: Mhlanga, Richwell
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365689 , vital:65776
- Description: Thesis access embargoed. Expected released date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mhlanga, Richwell
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365689 , vital:65776
- Description: Thesis access embargoed. Expected released date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Colonial displacements and African coping strategies: The experience of BaTonga of Binga, Zimbabwe, 1956-2008
- Authors: Dhodho, Codelia Govha
- Date: 2022-10-14
- Subjects: Tonga (Zambezi people) Refugees , Subsistence farming Zambezi River Valley , Hunger Zambezi River Valley , Food security Zambezi River Valley , Adaptability (Psychology) , Food relief Zambezi River Valley , Non-governmental organizations , Kariba Dam (Zambia and Zimbabwe)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327642 , vital:61139 , DOI 10.21504/10962/327642
- Description: This study examines the challenges faced by BaTonga in livelihood reconstruction after involuntary displacement and resettlement from the Zambezi valley to pave way for the Kariba dam reservoir. It shows how they were forcibly evicted without compensation because of the racist policies of Southern Rhodesia. Their resettlement into an arid region infested with marauding elephants, malaria and tsetse fly undermined their complex livelihoods and eroded their self-sufficiency, but the study argues that they were active and resilient agents who adopted complex coping strategies. It shows how they had to adapt to dry-land farming and counter the effects of wildlife which plundered their crops and managed to secure the harvest in the drought-prone region. The study shows that although they adopted precarious livelihoods, they managed to survive under extreme circumstances for decades without any external assistance until the coming of NGOs who began to distribute free food from 1982. It argues that prolonged distribution of emergence food aid may not have been necessary, but its coming for almost three decades largely served political interests of both the NGOs and their governments. This perpetuated poverty as BaTonga also manipulated its distribution as a coping strategy against fragile livelihoods. This caused dependency which further plunged them into chronic food insecurity because they abandoned their traditional coping strategies. The study argues that both the colonial and postcolonial government as well as NGOs failed to address the root causes of livelihood insecurity in Binga for the five decades under study. It is therefore the contention of this study that the problem of food insecurity in Binga was not only an issue of recurring drought but was deeply rooted and pervasive due to multiple complex factors which made it difficult for the people to establish sustainable food production after displacement. , Thesis (PhD) -- Faculty of Humanities, History, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Dhodho, Codelia Govha
- Date: 2022-10-14
- Subjects: Tonga (Zambezi people) Refugees , Subsistence farming Zambezi River Valley , Hunger Zambezi River Valley , Food security Zambezi River Valley , Adaptability (Psychology) , Food relief Zambezi River Valley , Non-governmental organizations , Kariba Dam (Zambia and Zimbabwe)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327642 , vital:61139 , DOI 10.21504/10962/327642
- Description: This study examines the challenges faced by BaTonga in livelihood reconstruction after involuntary displacement and resettlement from the Zambezi valley to pave way for the Kariba dam reservoir. It shows how they were forcibly evicted without compensation because of the racist policies of Southern Rhodesia. Their resettlement into an arid region infested with marauding elephants, malaria and tsetse fly undermined their complex livelihoods and eroded their self-sufficiency, but the study argues that they were active and resilient agents who adopted complex coping strategies. It shows how they had to adapt to dry-land farming and counter the effects of wildlife which plundered their crops and managed to secure the harvest in the drought-prone region. The study shows that although they adopted precarious livelihoods, they managed to survive under extreme circumstances for decades without any external assistance until the coming of NGOs who began to distribute free food from 1982. It argues that prolonged distribution of emergence food aid may not have been necessary, but its coming for almost three decades largely served political interests of both the NGOs and their governments. This perpetuated poverty as BaTonga also manipulated its distribution as a coping strategy against fragile livelihoods. This caused dependency which further plunged them into chronic food insecurity because they abandoned their traditional coping strategies. The study argues that both the colonial and postcolonial government as well as NGOs failed to address the root causes of livelihood insecurity in Binga for the five decades under study. It is therefore the contention of this study that the problem of food insecurity in Binga was not only an issue of recurring drought but was deeply rooted and pervasive due to multiple complex factors which made it difficult for the people to establish sustainable food production after displacement. , Thesis (PhD) -- Faculty of Humanities, History, 2022
- Full Text:
- Date Issued: 2022-10-14
Composition Portfolio
- Authors: Hanmer, Paul Dylan
- Date: 2022-10-14
- Subjects: Composition (Music) , String quartets Scores , Symphonies Scores , Music South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327283 , vital:61100 , DOI 10.21504/10962/327283
- Description: Extract from Introduction: “In the cover bands I worked with, I used to do what all my colleagues in these bands were doing to learn and remember repertoire; transcribe “by ear” and then rehearse with the whole band. Later, when I joined “909” [a cover band named after the “909” model of drum-box developed and built by the Japanese company, Roland] I learned to extend that skill by notating my transcriptions and then playing from these self-made keyboard parts. All the instrumentalists in that band likewise played from their own notated transcriptions and, from that time onward it became rarer for me to do any kind of performance work without a set of self-made parts to read from or refer to. I had thus reverted to performing from musical notation. Even later, when I became involved almost exclusively in improvisational music performance, I never quite abandoned the notion of having notated keyboard or piano parts to hand, as a reference or guide. Since about 1990, I have led a life that has increasingly left pop music behind and instead embraced working with improvising musicians; those who wish to explore South African folk idioms in their compositional and performance output, as well as others who have a deep love of jazz music. At the same time, I have re-entered the realm of classical music and music-making; often through writing arrangements of my own music, which would incorporate classically trained players, as well as in response to commissions to compose [for particular musicians or groups of musicians] fully notated pieces of music – such as the works in this PhD portfolio. Yet, there are many circumstantial factors that feed into my composing, and exert an influence on my creativity. A major step in this particular direction came during 2002 when composer, Michael Blake, asked me to contribute to The Bow Project. This commission brought me into close contact with the [then intact and very active] Sontonga Quartet. Several further requests for, and commissions of, new works followed on from there. Two such works constitute the major portion of the portfolio to which these reflexive commentaries refer.” , Thesis (PhD) -- Faculty of Humanities, Music and Musicology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Hanmer, Paul Dylan
- Date: 2022-10-14
- Subjects: Composition (Music) , String quartets Scores , Symphonies Scores , Music South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327283 , vital:61100 , DOI 10.21504/10962/327283
- Description: Extract from Introduction: “In the cover bands I worked with, I used to do what all my colleagues in these bands were doing to learn and remember repertoire; transcribe “by ear” and then rehearse with the whole band. Later, when I joined “909” [a cover band named after the “909” model of drum-box developed and built by the Japanese company, Roland] I learned to extend that skill by notating my transcriptions and then playing from these self-made keyboard parts. All the instrumentalists in that band likewise played from their own notated transcriptions and, from that time onward it became rarer for me to do any kind of performance work without a set of self-made parts to read from or refer to. I had thus reverted to performing from musical notation. Even later, when I became involved almost exclusively in improvisational music performance, I never quite abandoned the notion of having notated keyboard or piano parts to hand, as a reference or guide. Since about 1990, I have led a life that has increasingly left pop music behind and instead embraced working with improvising musicians; those who wish to explore South African folk idioms in their compositional and performance output, as well as others who have a deep love of jazz music. At the same time, I have re-entered the realm of classical music and music-making; often through writing arrangements of my own music, which would incorporate classically trained players, as well as in response to commissions to compose [for particular musicians or groups of musicians] fully notated pieces of music – such as the works in this PhD portfolio. Yet, there are many circumstantial factors that feed into my composing, and exert an influence on my creativity. A major step in this particular direction came during 2002 when composer, Michael Blake, asked me to contribute to The Bow Project. This commission brought me into close contact with the [then intact and very active] Sontonga Quartet. Several further requests for, and commissions of, new works followed on from there. Two such works constitute the major portion of the portfolio to which these reflexive commentaries refer.” , Thesis (PhD) -- Faculty of Humanities, Music and Musicology, 2022
- Full Text:
- Date Issued: 2022-10-14
Country risk and stock market volatility in Africa: Measuring the contribution of political and economic risk factors
- Authors: Hoveni, Jamela Basani
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405445 , vital:70172
- Description: Thesis embargoed. To be released in 2025. , Thesis (PhD) -- Faculty of Commerce, Economics and economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Hoveni, Jamela Basani
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405445 , vital:70172
- Description: Thesis embargoed. To be released in 2025. , Thesis (PhD) -- Faculty of Commerce, Economics and economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
Demand-side factors and the employment of young people: A case study of the recruitment and selection strategies of selected firms in Johannesburg
- Gabobegwe, Maoshadi Keletso Amanda
- Authors: Gabobegwe, Maoshadi Keletso Amanda
- Date: 2022-10-14
- Subjects: Unemployment South Africa , Underemployment South Africa , Unemployed youth South Africa , Labor market South Africa , Employees Recruiting South Africa , Employer attitude surveys South Africa , International Labour Organisation
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327294 , vital:61101 , DOI 10.21504/10962/327294
- Description: Unemployment is a long-standing and pressing socio-economic phenomenon that affects, markedly, both developed and developing countries. Although, in one way or another, many people are affected by unemployment, the reviewed literature concurs that youth unemployment is a critical component of the overall unemployment challenge. Indeed, the burden of unemployment is borne, tremendously, by young people, especially those who are Not in Education, Employment, or Training (NEETs). The International Labour Organisation (ILO) has declared youth unemployment a global crisis, with approximately 67,6 million unemployed young people worldwide in 2018. In South Africa, the youth unemployment rate escalated to 56.4 per cent in the second quarter of 2019. This disturbing level of unemployment among young people poses a serious threat—for as long as young people stay unemployed. Indeed, the cost of unemployment is too high, not only does it engender discontent among young people who are floundering in poverty and frustration, but it can also trigger or perpetuate all sorts of social, political, and economic effects. These effects only exacerbate the already intricate and onerous global agenda of tackling unemployment— because they give rise to other socio-economic ills (e.g., crime, among others) that also need to be addressed. Owing to this grave and perpetual challenge of unemployment, exploring and understanding the dynamics of youth unemployment continues to be of paramount importance worldwide. This thesis, in particular, seeks to investigate the factors that impede on the employment of the NEETs category, as it may be extremely difficult for them to enter the labour market— and they may lose hope of entering the labour market later in life, if they are unsuccessful while still young. Unlike graduates or other youth categories (i.e., matriculants) who have better chances in the labour market, some young people (by virtue of being ‘dropouts’, teenage moms/dads, having failed matric, among other reasons), remain the most vulnerable to unemployment. For this reason, the primary aim of this thesis is to examine the ways in which employers’ recruitment strategies advantage or disadvantage young people (NEETs). The secondary aims include: (a) examining how employers' perceptions and attitudes, regarding the NEETs youths, influence their recruitment decisions when it comes to employing young people; and (b) understanding the ways in which government strategies (devised to combat youth unemployment) influence employers’ decisions to recruit the youths’ or not. In essence, this study seeks to explore the demand-side factors in the labour market that can help us understand how employers’ recruitment decisions (or recruitment behaviour) affect the employment prospects of young people in the labour market. The focus on demand-side factors is motivated by Labour Market Segmentation (LMS) theories, which serve as the theoretical framework of this thesis. LMS theories’ significance lies in their opposition to neoclassical economics, that posit the existence of a unified labour market (which operates like all other markets), consisting of buyers and sellers in ‘free’ competition. According to neoclassical theory, the difference between workers’ employment and wages is determined by ‘individual preferences’ and investments in ‘human capital’ (skills, experience, formal education, etc.). By contrast, LMS theorists argue that labour markets are fragmented, and that differences on the demand side imply differences in compensations that are not totally determined by individual workers' human capital. Inspired by the claims of LMS theories, this study elected to explore demand-side factors by applying qualitative research methods and techniques to gather and analyse the data gathered, and to ultimately address the research objectives. In particular, non-probability sampling was used to sample 20 firms from four sectors (manufacturing, retail/hospitality, finance, transportation) in the Johannesburg (CBD) region. The respondents were all asked a series of semi-structured questions in order to yield qualitative results that would help determine the employers’ dispositions towards young people; and about the government’s strategies that address youth unemployment. The aim is to provide an in-depth, nuanced understanding of how the respondents’ dispositions influence the inclusion or exclusion of young people in the employers’ recruitment considerations. The aggregate results of the study generally indicate that—although there are innumerable factors that affect young peoples' employment prospects—young people (without skills and tertiary education or matric) are actually being employed, and are still being considered for employment by the majority of the sampled employers (predominantly from retail/hospitality firms). Only a minority of employers stated, categorically, that they do not employ young people, and do not intend to do so. Conversely, the results also reveal that the the majority of employers often recruit young people for general and entry-level jobs that are often offered on a non-standard employment basis. At face value, the employment of young people (without skills) in the majority of the sampled firms may seem to make a difference—and it probably does, for as long as young people are exposed to the world of work. However, in the 4 grand scheme of things, the kind of employment offered in these firms is also problematic, because it is, basically, transient and unsustainable. As such, the young people that occupy these jobs are most likely to find themselves back in the unemployment queues whenever the ‘part-time’ or ‘temporary’ employment contracts are terminated. These jobs are especially problematic because policies such as the National Development Plan (NDP) 2030—in line with Sustainable Development Goals—aim to reduce poverty by creating sustainable employment. Contrarily, these kinds of jobs make it hard to achieve poverty reduction, because they are inherently unsustainable and barely lift people (especially young people) from unemployment and poverty. Based on these results, it can be asserted that the proliferation of non-standard employment compromises the agenda for decent work, and it delays the already sluggish Sustainable Development goal of creating sustainable employment (among other goals). This, then, reveals that there is still a stark and long-standing need for more radical strategies that will ensure the creation of sustainable jobs—without which the unemployment crisis will be far from over. Moreover, the results further indicate that the reasons why the minority of the sampled employers do not employ young people boil down to the fact that young people usually do not have what employers look for in their potential recruits; or that young people do not have what employers believe will contribute to the growth and productivity of their firms. In essence, employers will never employ any young person (or any jobseeker in general) that will be a liability than an asset in their firms. Over and above, this thesis corroborates many of the explanations—encapsulated in the growing literature—for rising unemployment, as well as the claims that unemployment is highly pronounced among young people. However, the contribution of this thesis is that it further offers a nuanced view to understanding the demand-side factors (as additional determinants) that hinder the employment of young people (especially those who make up the NEETs category). , Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Gabobegwe, Maoshadi Keletso Amanda
- Date: 2022-10-14
- Subjects: Unemployment South Africa , Underemployment South Africa , Unemployed youth South Africa , Labor market South Africa , Employees Recruiting South Africa , Employer attitude surveys South Africa , International Labour Organisation
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327294 , vital:61101 , DOI 10.21504/10962/327294
- Description: Unemployment is a long-standing and pressing socio-economic phenomenon that affects, markedly, both developed and developing countries. Although, in one way or another, many people are affected by unemployment, the reviewed literature concurs that youth unemployment is a critical component of the overall unemployment challenge. Indeed, the burden of unemployment is borne, tremendously, by young people, especially those who are Not in Education, Employment, or Training (NEETs). The International Labour Organisation (ILO) has declared youth unemployment a global crisis, with approximately 67,6 million unemployed young people worldwide in 2018. In South Africa, the youth unemployment rate escalated to 56.4 per cent in the second quarter of 2019. This disturbing level of unemployment among young people poses a serious threat—for as long as young people stay unemployed. Indeed, the cost of unemployment is too high, not only does it engender discontent among young people who are floundering in poverty and frustration, but it can also trigger or perpetuate all sorts of social, political, and economic effects. These effects only exacerbate the already intricate and onerous global agenda of tackling unemployment— because they give rise to other socio-economic ills (e.g., crime, among others) that also need to be addressed. Owing to this grave and perpetual challenge of unemployment, exploring and understanding the dynamics of youth unemployment continues to be of paramount importance worldwide. This thesis, in particular, seeks to investigate the factors that impede on the employment of the NEETs category, as it may be extremely difficult for them to enter the labour market— and they may lose hope of entering the labour market later in life, if they are unsuccessful while still young. Unlike graduates or other youth categories (i.e., matriculants) who have better chances in the labour market, some young people (by virtue of being ‘dropouts’, teenage moms/dads, having failed matric, among other reasons), remain the most vulnerable to unemployment. For this reason, the primary aim of this thesis is to examine the ways in which employers’ recruitment strategies advantage or disadvantage young people (NEETs). The secondary aims include: (a) examining how employers' perceptions and attitudes, regarding the NEETs youths, influence their recruitment decisions when it comes to employing young people; and (b) understanding the ways in which government strategies (devised to combat youth unemployment) influence employers’ decisions to recruit the youths’ or not. In essence, this study seeks to explore the demand-side factors in the labour market that can help us understand how employers’ recruitment decisions (or recruitment behaviour) affect the employment prospects of young people in the labour market. The focus on demand-side factors is motivated by Labour Market Segmentation (LMS) theories, which serve as the theoretical framework of this thesis. LMS theories’ significance lies in their opposition to neoclassical economics, that posit the existence of a unified labour market (which operates like all other markets), consisting of buyers and sellers in ‘free’ competition. According to neoclassical theory, the difference between workers’ employment and wages is determined by ‘individual preferences’ and investments in ‘human capital’ (skills, experience, formal education, etc.). By contrast, LMS theorists argue that labour markets are fragmented, and that differences on the demand side imply differences in compensations that are not totally determined by individual workers' human capital. Inspired by the claims of LMS theories, this study elected to explore demand-side factors by applying qualitative research methods and techniques to gather and analyse the data gathered, and to ultimately address the research objectives. In particular, non-probability sampling was used to sample 20 firms from four sectors (manufacturing, retail/hospitality, finance, transportation) in the Johannesburg (CBD) region. The respondents were all asked a series of semi-structured questions in order to yield qualitative results that would help determine the employers’ dispositions towards young people; and about the government’s strategies that address youth unemployment. The aim is to provide an in-depth, nuanced understanding of how the respondents’ dispositions influence the inclusion or exclusion of young people in the employers’ recruitment considerations. The aggregate results of the study generally indicate that—although there are innumerable factors that affect young peoples' employment prospects—young people (without skills and tertiary education or matric) are actually being employed, and are still being considered for employment by the majority of the sampled employers (predominantly from retail/hospitality firms). Only a minority of employers stated, categorically, that they do not employ young people, and do not intend to do so. Conversely, the results also reveal that the the majority of employers often recruit young people for general and entry-level jobs that are often offered on a non-standard employment basis. At face value, the employment of young people (without skills) in the majority of the sampled firms may seem to make a difference—and it probably does, for as long as young people are exposed to the world of work. However, in the 4 grand scheme of things, the kind of employment offered in these firms is also problematic, because it is, basically, transient and unsustainable. As such, the young people that occupy these jobs are most likely to find themselves back in the unemployment queues whenever the ‘part-time’ or ‘temporary’ employment contracts are terminated. These jobs are especially problematic because policies such as the National Development Plan (NDP) 2030—in line with Sustainable Development Goals—aim to reduce poverty by creating sustainable employment. Contrarily, these kinds of jobs make it hard to achieve poverty reduction, because they are inherently unsustainable and barely lift people (especially young people) from unemployment and poverty. Based on these results, it can be asserted that the proliferation of non-standard employment compromises the agenda for decent work, and it delays the already sluggish Sustainable Development goal of creating sustainable employment (among other goals). This, then, reveals that there is still a stark and long-standing need for more radical strategies that will ensure the creation of sustainable jobs—without which the unemployment crisis will be far from over. Moreover, the results further indicate that the reasons why the minority of the sampled employers do not employ young people boil down to the fact that young people usually do not have what employers look for in their potential recruits; or that young people do not have what employers believe will contribute to the growth and productivity of their firms. In essence, employers will never employ any young person (or any jobseeker in general) that will be a liability than an asset in their firms. Over and above, this thesis corroborates many of the explanations—encapsulated in the growing literature—for rising unemployment, as well as the claims that unemployment is highly pronounced among young people. However, the contribution of this thesis is that it further offers a nuanced view to understanding the demand-side factors (as additional determinants) that hinder the employment of young people (especially those who make up the NEETs category). , Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Date Issued: 2022-10-14
Development of biosensor systems for the detection of anti-cancer drugs and prostate cancer
- Authors: Mwanza, Daniel
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365929 , vital:65803
- Description: Thesis embargoed. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mwanza, Daniel
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365929 , vital:65803
- Description: Thesis embargoed. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-10-14
Disentangling the role of prokaryotes in regulating export flux via suspended and sinking organic matter in the southern ocean
- Authors: Dithugoe, Choaro David
- Date: 2022-10-14
- Subjects: Microbial ecology , Bioinformatics , Biochemistry , Oceanography , Metagenomics , Carbon cycle (Biogeochemistry) , Prokaryotes
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365745 , vital:65782 , DOI https://doi.org/10.21504/10962/365745
- Description: The role of phytoplankton in regulating atmospheric carbon dioxide in the marine environment has been the subject of extensive research. We lack, however, comparative insights regarding the functional contributions of bacteria, archaea, fungi, and viruses (the microbiota) to organic matter export especially in understudied polar marine environments such as the Southern Ocean. This knowledge deficit is in part due to the high levels of microbial diversity which obscures efforts to study the relationship between diversity and ecosystem functions including their roles in the sequestration of carbon and nitrogen. Elucidating their precise contributions to organic matter export may be central to potential ecosystems feedbacks to global climate change. We examined several factors which may influence organic matter export to depth including net primary production, phytoplankton biomass, temperature, and prokaryotic functional capacity in the Southern Ocean. A Marine Snow Catcher was used to collect suspended and sinking material 10 metres below mixed layer depth at Southern Ocean Time Series (SOTS) in autumn (March-April) and in the Atlantic sector of the Southern Ocean in winter (July-August) and spring (October-November) 2019. The suspended and sinking material was used to determine the particulate organic carbon and nitrogen concentrations which were then used to calculate fluxes and export ratio ((e-ratio) - particulate organic carbon flux divided by net primary production). Additionally, genomic DNA was extracted from the suspended and sinking material and sequenced to obtain Shotgun metagenomic data which was employed to reconstruct metagenome assembled genome (MAGs) and their functional capacity using bioinformatic tools such as DRAM. Data from the Atlantic sector of the Southern Ocean, demonstrate that net primary production and temperature were inversely related to the e-ratio which is consistent with previous findings from the northern region of the Southern Ocean. Genomic functional capacity from SOTS suggested that r-strategist (organisms adapted to live in unstable environments) bacteria (e.g., Gammaproteobacteria) were prominent in the suspended pool. By contrast, the sinking particle-pool appeared to be dominated by K- strategists (organisms adapted to stable environment). The opposite was true for the archaea. This finding (i.e., bacteria) differs from a previous study in the northern region of the Southern Ocean, showing that microbes with K-strategists were more abundant in the suspended fraction. K-strategists typically degrade sinking organic matter into suspended organic matter or dissolved organic matter reducing the organic carbon export efficiency. Furthermore, Data from the Atlantic sector of the Southern Ocean revealed that seasonal temperature changes might dictate the rate of regional prokaryotic degradation across the zones. Resulting in rapid degradation at the northerly warmer regions and slow degradation further south. The data further provide evidence of chemolithoautotrophic mechanisms, with prokaryotes harbouring key pathways, required to transform dissolved inorganic carbon into complex organic forms, including recalcitrant dissolved organic carbon. Collectively, the SOTS and Atlantic sector of the Southern Ocean data suggest that shifts in prokaryotic community structure and functional capacity may regulate (either degradation or synthesis of organic matter) carbon export to depth. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Dithugoe, Choaro David
- Date: 2022-10-14
- Subjects: Microbial ecology , Bioinformatics , Biochemistry , Oceanography , Metagenomics , Carbon cycle (Biogeochemistry) , Prokaryotes
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365745 , vital:65782 , DOI https://doi.org/10.21504/10962/365745
- Description: The role of phytoplankton in regulating atmospheric carbon dioxide in the marine environment has been the subject of extensive research. We lack, however, comparative insights regarding the functional contributions of bacteria, archaea, fungi, and viruses (the microbiota) to organic matter export especially in understudied polar marine environments such as the Southern Ocean. This knowledge deficit is in part due to the high levels of microbial diversity which obscures efforts to study the relationship between diversity and ecosystem functions including their roles in the sequestration of carbon and nitrogen. Elucidating their precise contributions to organic matter export may be central to potential ecosystems feedbacks to global climate change. We examined several factors which may influence organic matter export to depth including net primary production, phytoplankton biomass, temperature, and prokaryotic functional capacity in the Southern Ocean. A Marine Snow Catcher was used to collect suspended and sinking material 10 metres below mixed layer depth at Southern Ocean Time Series (SOTS) in autumn (March-April) and in the Atlantic sector of the Southern Ocean in winter (July-August) and spring (October-November) 2019. The suspended and sinking material was used to determine the particulate organic carbon and nitrogen concentrations which were then used to calculate fluxes and export ratio ((e-ratio) - particulate organic carbon flux divided by net primary production). Additionally, genomic DNA was extracted from the suspended and sinking material and sequenced to obtain Shotgun metagenomic data which was employed to reconstruct metagenome assembled genome (MAGs) and their functional capacity using bioinformatic tools such as DRAM. Data from the Atlantic sector of the Southern Ocean, demonstrate that net primary production and temperature were inversely related to the e-ratio which is consistent with previous findings from the northern region of the Southern Ocean. Genomic functional capacity from SOTS suggested that r-strategist (organisms adapted to live in unstable environments) bacteria (e.g., Gammaproteobacteria) were prominent in the suspended pool. By contrast, the sinking particle-pool appeared to be dominated by K- strategists (organisms adapted to stable environment). The opposite was true for the archaea. This finding (i.e., bacteria) differs from a previous study in the northern region of the Southern Ocean, showing that microbes with K-strategists were more abundant in the suspended fraction. K-strategists typically degrade sinking organic matter into suspended organic matter or dissolved organic matter reducing the organic carbon export efficiency. Furthermore, Data from the Atlantic sector of the Southern Ocean revealed that seasonal temperature changes might dictate the rate of regional prokaryotic degradation across the zones. Resulting in rapid degradation at the northerly warmer regions and slow degradation further south. The data further provide evidence of chemolithoautotrophic mechanisms, with prokaryotes harbouring key pathways, required to transform dissolved inorganic carbon into complex organic forms, including recalcitrant dissolved organic carbon. Collectively, the SOTS and Atlantic sector of the Southern Ocean data suggest that shifts in prokaryotic community structure and functional capacity may regulate (either degradation or synthesis of organic matter) carbon export to depth. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-10-14
Don’t let the little man live in your head for free: an interpretive phenomenological analysis of seafarers with reportedly high levels of well-being
- Authors: Brown, Lauren Natalie
- Date: 2022-10-14
- Subjects: Seafaring life Psychological aspects , Sailors Mental health , Well-being , Phenomenology , Work environment
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327653 , vital:61140 , DOI 10.21504/10962/327653
- Description: The mental health of seafarers has become a growing issue of concern and has attracted the attention of researchers in recent times. Seafarers are predominantly men, spend months at sea with little to no contact with loved ones ashore, and usually must reside in confined spaces that often contain substantial levels of noise and heat. The underlying causes of mental illness among seafarers are known. Some of the causes include sleep deprivation, occupational stress, marital/relationship problems, fatigue, the threat of piracy, psychosocial workload, loneliness, social isolation, separation from families, lack of shore leave, cultural issues, and job security. Despite these stressors, there are many men and women seafarers who flourish in the industry and enjoy their careers. Very little research has been conducted into the well-being practices of those seafarers who enjoy high levels of well-being. This study explores the lived experiences of a group of seafarers with reportedly high levels of psychological well-being, as well as their experiences of workplace stressors and mental health interventions offered by the industry. This study is an interpretive phenomenological analysis, which is epistemologically underpinned by phenomenology, hermeneutics and idiography. Results revealed four focus areas: general lived experiences across two worlds and how this relates to identity, what seafarers with reportedly high levels of psychological well-being experience as stressors, well-being practices of these seafarers and how these seafarers experience and make sense of mental health interventions they have come across. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Brown, Lauren Natalie
- Date: 2022-10-14
- Subjects: Seafaring life Psychological aspects , Sailors Mental health , Well-being , Phenomenology , Work environment
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327653 , vital:61140 , DOI 10.21504/10962/327653
- Description: The mental health of seafarers has become a growing issue of concern and has attracted the attention of researchers in recent times. Seafarers are predominantly men, spend months at sea with little to no contact with loved ones ashore, and usually must reside in confined spaces that often contain substantial levels of noise and heat. The underlying causes of mental illness among seafarers are known. Some of the causes include sleep deprivation, occupational stress, marital/relationship problems, fatigue, the threat of piracy, psychosocial workload, loneliness, social isolation, separation from families, lack of shore leave, cultural issues, and job security. Despite these stressors, there are many men and women seafarers who flourish in the industry and enjoy their careers. Very little research has been conducted into the well-being practices of those seafarers who enjoy high levels of well-being. This study explores the lived experiences of a group of seafarers with reportedly high levels of psychological well-being, as well as their experiences of workplace stressors and mental health interventions offered by the industry. This study is an interpretive phenomenological analysis, which is epistemologically underpinned by phenomenology, hermeneutics and idiography. Results revealed four focus areas: general lived experiences across two worlds and how this relates to identity, what seafarers with reportedly high levels of psychological well-being experience as stressors, well-being practices of these seafarers and how these seafarers experience and make sense of mental health interventions they have come across. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-10-14