The self and the impossible pursuit of justice in J.M. Coetzee’s "Waiting for the barbarians, disgrace and foe”
- Authors: Swanepoel, Elbie
- Date: 2022-04-07
- Subjects: Coetzee, J M, 1940- Criticism and interpretation , Coetzee, J M, 1940- Waiting for the barbarians , Coetzee, J M, 1940- Disgrace , Coetzee, J M, 1940- Foe , Ethics in literature , Deconstruction , Postmodernism (Literature) , Justice in literature
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232294 , vital:49979
- Description: In its engagement with J.M. Coetzee’s Waiting for the Barbarians, Disgrace and Foe, this thesis explores how the philosophies of Emmanuel Levinas and Jacques Derrida can be used as a framework for understanding the self’s relationship with the other. In contrast to postcolonial readings of these texts, this thesis does not consider the separation between the self and the other in terms of social or cultural differences but rather the radical alterity of the other that is perceived in the face-to-face encounter. This study aims to illustrate how the engagement with alterity exposes the instability of the self’s structures of knowledge that, in these instances, are grounded in the Western metaphysical tradition. The effects of the self’s encounter with the other are seen in the personal transformation of Coetzee’s protagonists whose initial flaws and problematic worldviews are revealed in the context of the injustices done to the other. Furthermore, the study examines the extent to which the self is complicit in the suffering of the other and how this ultimately complicates their pursuit of justice for them. While the focus of this thesis is primarily on the characters, it also shows how the writer’s careful treatment of otherness functions to confront and engage the reader with the alterity of the other and the ethical dilemmas inherent in attempting to conceptualise it. The study concludes that the protagonists’ engagement with others and their subsequent confrontation with themselves lead them to consider what an ethical response to the other might be. This ethical turn results in positive change, however ambiguously, in their thoughts about and behaviours toward other beings. , Thesis (MA) -- Faculty of Humanities, English Language and Linguistics, 2022
- Full Text:
- Date Issued: 2022-04-07
- Authors: Swanepoel, Elbie
- Date: 2022-04-07
- Subjects: Coetzee, J M, 1940- Criticism and interpretation , Coetzee, J M, 1940- Waiting for the barbarians , Coetzee, J M, 1940- Disgrace , Coetzee, J M, 1940- Foe , Ethics in literature , Deconstruction , Postmodernism (Literature) , Justice in literature
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232294 , vital:49979
- Description: In its engagement with J.M. Coetzee’s Waiting for the Barbarians, Disgrace and Foe, this thesis explores how the philosophies of Emmanuel Levinas and Jacques Derrida can be used as a framework for understanding the self’s relationship with the other. In contrast to postcolonial readings of these texts, this thesis does not consider the separation between the self and the other in terms of social or cultural differences but rather the radical alterity of the other that is perceived in the face-to-face encounter. This study aims to illustrate how the engagement with alterity exposes the instability of the self’s structures of knowledge that, in these instances, are grounded in the Western metaphysical tradition. The effects of the self’s encounter with the other are seen in the personal transformation of Coetzee’s protagonists whose initial flaws and problematic worldviews are revealed in the context of the injustices done to the other. Furthermore, the study examines the extent to which the self is complicit in the suffering of the other and how this ultimately complicates their pursuit of justice for them. While the focus of this thesis is primarily on the characters, it also shows how the writer’s careful treatment of otherness functions to confront and engage the reader with the alterity of the other and the ethical dilemmas inherent in attempting to conceptualise it. The study concludes that the protagonists’ engagement with others and their subsequent confrontation with themselves lead them to consider what an ethical response to the other might be. This ethical turn results in positive change, however ambiguously, in their thoughts about and behaviours toward other beings. , Thesis (MA) -- Faculty of Humanities, English Language and Linguistics, 2022
- Full Text:
- Date Issued: 2022-04-07
The diversity and dry season habitat associations of fish communities in the Kabompo River Basin, Upper Zambezi, Zambia
- Authors: Rennie, Craig Lawrence
- Date: 2022-04-06
- Subjects: Biodiversity Zambia Kabompo District , Ecology Zambia Kabompo District , Fish communities Zambia Kabompo District , Fishes Ecology Zambia Kabompo District , Freshwater habitats Zambia Kabompo District , Fishes Effect of human beings on Zambia Kabompo District , Fishes Climatic factors Zambia Kabompo District , Mesohabitat
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232261 , vital:49976
- Description: The Zambezian headwaters contain diverse fish communities which support thriving fisheries. This region and its fishes are under pressure from multiple anthropogenic threats, including overexploitation and large-scale developments with potential knock-on effects for the riparian communities. Previous studies have focused on known fisheries areas and the mainstem Zambezi River, neglecting large tributaries such as the Kabompo River. Consequently, little literature is available on the diversity and ecology of the fishes that inhabit these large tributaries, hindering the effective management and protection of biodiversity. This study aimed to fill the current knowledge gaps in the diversity and habitat associations of fish communities in the Upper Zambezi, using the Kabompo River as a case study. The first objective was to provide an updated checklist of the fishes of the Kabompo River basin using a compilation of historical data and field surveys. This study detailed the occurrence and distribution of 83 fish species within the Kabompo River basin. All these species have been recorded in the Upper Zambezi, with some of their ranges extending into the Middle (29 species) and Lower Zambezi (23 species) while others have more restricted distributions. The most diverse families were the Cyprinidae (26 species) and the Cichlidae (15 species). A number of potential undescribed species, whose taxonomic distinctiveness need further investigation were also collected. Taxonomic conflicts are also highlighted for some of the taxa that were previously considered to have broad geographic ranges or disjunct distributions. Consistent with findings from other studies within the region, the current taxonomy underestimates the diversity of fishes in the Kabompo River and Upper Zambezi. The second objective was to assess the habitat use of small-bodied fish communities during the low-flow period in 2019. Reconnaissance trips identified dominant mesohabitats along the middle Kabompo River around Jivundu. A total of 139 mesohabitats were sampled across the five dominant mesohabitats identified; Phragmites mauritianus, wood, rock, Vallisneria aethiopica and bare substrate. Catch per unit effort, species richness, Shannon diversity and Pielou’s evenness differed significantly between these mesohabitats. Twenty-six species showed significant associations (p < 0.05) with a specific mesohabitat type or environmental variable (current velocity or depth). Eight species were associated with the woody habitat, with three of these, E. radiatus, E. unitaeniatus, and P. ngamensis being almost exclusively associated with this habitat. Enteromius kerstenii, E. lineomaculatus and S. depressirostris were almost exclusively associated with P. mauritianus and represent potential indicator species for this habitat. A number of species were also with both P. mauritianus and woody habitats. Nine species showed statistically significant associations with the rocky mesohabitat, with Amphilius uranoscopus and Petrocephalus longicapitis, being almost exclusive to rocky sections of the river. Therefore, species such as A. uranoscopus are potential indicators for monitoring the integrity of rocky habitats under threat from sedimentation. The strong associations indicate that this comprehensive baseline may be valuable indicators/ proxies for identifying anthropogenic induced change in the Kabompo basin. This would provide a basis to determine fish responses to regional environmental changes associated with human activities. , Thesis (MSc) -- Faculty of Science, Ichthyology & Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Rennie, Craig Lawrence
- Date: 2022-04-06
- Subjects: Biodiversity Zambia Kabompo District , Ecology Zambia Kabompo District , Fish communities Zambia Kabompo District , Fishes Ecology Zambia Kabompo District , Freshwater habitats Zambia Kabompo District , Fishes Effect of human beings on Zambia Kabompo District , Fishes Climatic factors Zambia Kabompo District , Mesohabitat
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232261 , vital:49976
- Description: The Zambezian headwaters contain diverse fish communities which support thriving fisheries. This region and its fishes are under pressure from multiple anthropogenic threats, including overexploitation and large-scale developments with potential knock-on effects for the riparian communities. Previous studies have focused on known fisheries areas and the mainstem Zambezi River, neglecting large tributaries such as the Kabompo River. Consequently, little literature is available on the diversity and ecology of the fishes that inhabit these large tributaries, hindering the effective management and protection of biodiversity. This study aimed to fill the current knowledge gaps in the diversity and habitat associations of fish communities in the Upper Zambezi, using the Kabompo River as a case study. The first objective was to provide an updated checklist of the fishes of the Kabompo River basin using a compilation of historical data and field surveys. This study detailed the occurrence and distribution of 83 fish species within the Kabompo River basin. All these species have been recorded in the Upper Zambezi, with some of their ranges extending into the Middle (29 species) and Lower Zambezi (23 species) while others have more restricted distributions. The most diverse families were the Cyprinidae (26 species) and the Cichlidae (15 species). A number of potential undescribed species, whose taxonomic distinctiveness need further investigation were also collected. Taxonomic conflicts are also highlighted for some of the taxa that were previously considered to have broad geographic ranges or disjunct distributions. Consistent with findings from other studies within the region, the current taxonomy underestimates the diversity of fishes in the Kabompo River and Upper Zambezi. The second objective was to assess the habitat use of small-bodied fish communities during the low-flow period in 2019. Reconnaissance trips identified dominant mesohabitats along the middle Kabompo River around Jivundu. A total of 139 mesohabitats were sampled across the five dominant mesohabitats identified; Phragmites mauritianus, wood, rock, Vallisneria aethiopica and bare substrate. Catch per unit effort, species richness, Shannon diversity and Pielou’s evenness differed significantly between these mesohabitats. Twenty-six species showed significant associations (p < 0.05) with a specific mesohabitat type or environmental variable (current velocity or depth). Eight species were associated with the woody habitat, with three of these, E. radiatus, E. unitaeniatus, and P. ngamensis being almost exclusively associated with this habitat. Enteromius kerstenii, E. lineomaculatus and S. depressirostris were almost exclusively associated with P. mauritianus and represent potential indicator species for this habitat. A number of species were also with both P. mauritianus and woody habitats. Nine species showed statistically significant associations with the rocky mesohabitat, with Amphilius uranoscopus and Petrocephalus longicapitis, being almost exclusive to rocky sections of the river. Therefore, species such as A. uranoscopus are potential indicators for monitoring the integrity of rocky habitats under threat from sedimentation. The strong associations indicate that this comprehensive baseline may be valuable indicators/ proxies for identifying anthropogenic induced change in the Kabompo basin. This would provide a basis to determine fish responses to regional environmental changes associated with human activities. , Thesis (MSc) -- Faculty of Science, Ichthyology & Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04-06
The use of photography to visualise abstracted narratives of emotions associated with trauma
- Authors: Warner, Lauren
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54585 , vital:46726
- Description: The purpose of this qualitative research study is to comment on the use of photography to visualise abstracted narratives of the emotions associated with trauma. This is a practicebased study developed on the interweaving of theoretical and practical output. The practical output produced a photographic body of work which argues in favour of an abstracted narrative for the visualisation of trauma by engaging with visualised emotions associated with trauma. The theoretical output of the study relates to three visual themes: firstly, the direct or actual moment of trauma; secondly, the triggering of the traumatic experience and lastly, the abstracted narrative of emotions associated with trauma. Photographing a traumatic event freezes a moment in which the subjects are continually engaging in the traumatic experience. Sontag (2003: 93) asserts that this type of direct photographic representation should be discouraged for fear of aestheticising pain and desensitising the viewer to horror. The study aims not to visualise actual traumatic events, but rather to engage with abstracted narratives of emotions associated with trauma experienced or felt, both directly and indirectly. This is achieved by firstly, providing a context on how the role of photography dealing with trauma has evolved to move beyond the depiction of an actual traumatic experience. Secondly, Gillian Rose’s (2016) Visual Methodologies Framework is introduced and photographers Roger Ballen’s Cut Loose (2015) and Jo Ractliffe’s 1999 work entitled Vlakplaas: 2 June 1999 (Drive-by Shooting) analysed as visual expressions of trauma. Similarly, photographers Robert Frank’s 1978 work entitled Sick of goodby’s and Manuela Thames’s 2019 work entitled Trauma are analysed to reflect on the use of abstracted narratives as they comment on personal traumatic experiences. Lastly, the body of work produced in the practice-based output of the study, Public Places: Private Spaces, are analysed as a vehicle through which emotions are associated with trauma. These traumatic experiences are visually expressed using abstracted images in triptych narratives. This study contributes to the current body of knowledge by critically addressing ways of thinking about the visualisation of trauma. This provides insight into the topic of trauma and the various ways in which it could be visualised without depicting the actual trauma (with the potential of continuously wounding or replaying trauma) and instead engaging with the visualised traumatic experience as an abstracted narrative within a South African context. , Thesis (MA) -- Faculty of Humanities, School of Visual and Performing Arts, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Warner, Lauren
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54585 , vital:46726
- Description: The purpose of this qualitative research study is to comment on the use of photography to visualise abstracted narratives of the emotions associated with trauma. This is a practicebased study developed on the interweaving of theoretical and practical output. The practical output produced a photographic body of work which argues in favour of an abstracted narrative for the visualisation of trauma by engaging with visualised emotions associated with trauma. The theoretical output of the study relates to three visual themes: firstly, the direct or actual moment of trauma; secondly, the triggering of the traumatic experience and lastly, the abstracted narrative of emotions associated with trauma. Photographing a traumatic event freezes a moment in which the subjects are continually engaging in the traumatic experience. Sontag (2003: 93) asserts that this type of direct photographic representation should be discouraged for fear of aestheticising pain and desensitising the viewer to horror. The study aims not to visualise actual traumatic events, but rather to engage with abstracted narratives of emotions associated with trauma experienced or felt, both directly and indirectly. This is achieved by firstly, providing a context on how the role of photography dealing with trauma has evolved to move beyond the depiction of an actual traumatic experience. Secondly, Gillian Rose’s (2016) Visual Methodologies Framework is introduced and photographers Roger Ballen’s Cut Loose (2015) and Jo Ractliffe’s 1999 work entitled Vlakplaas: 2 June 1999 (Drive-by Shooting) analysed as visual expressions of trauma. Similarly, photographers Robert Frank’s 1978 work entitled Sick of goodby’s and Manuela Thames’s 2019 work entitled Trauma are analysed to reflect on the use of abstracted narratives as they comment on personal traumatic experiences. Lastly, the body of work produced in the practice-based output of the study, Public Places: Private Spaces, are analysed as a vehicle through which emotions are associated with trauma. These traumatic experiences are visually expressed using abstracted images in triptych narratives. This study contributes to the current body of knowledge by critically addressing ways of thinking about the visualisation of trauma. This provides insight into the topic of trauma and the various ways in which it could be visualised without depicting the actual trauma (with the potential of continuously wounding or replaying trauma) and instead engaging with the visualised traumatic experience as an abstracted narrative within a South African context. , Thesis (MA) -- Faculty of Humanities, School of Visual and Performing Arts, 2021
- Full Text:
- Date Issued: 2021-12
An epistemic justice account of students’ experiences of feedback
- Authors: Vilakazi, Bella Phetheni
- Date: 2022-04-08
- Subjects: Feedback (Psychology) , Experience , Narrative inquiry (Research method) , Critical thinking , Caring Moral and ethical aspects , Epistemic access
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232599 , vital:50006 , DOI 10.21504/10962/232599
- Description: I am a storyteller. I believe in the power of stories to share experiences and to elucidate thoughts and ideas and to help us to make sense of complex social practices. This thesis includes the stories of five young women who were learning to become teachers. As they shared their stories with me, I share them with you. This study includes their stories of receiving feedback. These stories are structured within the Narrative Inquiry dimensions of temporality, place and context. These dimensions suggest that stories are historical and move through time, stories are shaped by place and the context in which they unfold (Clandinin, 2013). Furthermore, these stories demonstrate how feedback can serve to give access to powerful knowledge and can serve to recognise who our students are and what they bring to the academy (Hordern, 2018). But feedback can also serve to misrecognise. Much has been written and reported about the barriers preventing students from acting on the feedback on their assignment tasks in higher education. In this study, I argue that feedback is a pedagogic practice that can support students to gain epistemic access. Feedback can only achieve this if it makes the expectations explicit for students to make sense of and make meaning for themselves and if it is offered in a dialogical format which recognises the students, their attempts, their identities, and their knowledge. The research question of this study, ‘How do experiences of forms of feedback affect female undergraduate student teachers’ chances of epistemic access?’, is not unusual. There have been many research projects that have been carried out that examine students’ experiences of feedback (for example, Evans, 2013; Basey, Maines, & Francis, 2014; Nicol et al.; 2014; Carless, 2019; Winstone et al., 2021). But I identified a gap where feedback has not, to my knowledge, been studied directly through the lenses of Epistemic Justice towards Parity of Participation. This study interpreted five undergraduate student teachers’ feedback experiences through these lenses. Narrative inquiry enabled me to design this study in ways that foregrounded experience. Data was collected through multiple conversations during which I organised the participants’ life stories of feedback within the dimensions of temporality, place and context, and sociality. Miranda Fricker’s (2007) theory of Epistemic Justice and Fraser’s norm of Parity of Participation (2000) framed this study. I engaged with Fricker and Fraser’s literature meaningfully as a reader and researcher. I established an understanding of how the lenses offered by Fraser and Fricker allowed me to make sense of the literature more generally, in social life and on the pedagogic practice of feedback. Fricker’s theory of Epistemic Justice considers the epistemically unjust, gendered, raced and classed, experiences of epistemic agents. Fricker (2007) draws on two central concepts to account for epistemic injustices: Testimonial Injustice and Hermeneutical Injustice. Fricker (2007; 2003) explains that testimonial injustice occurs within a testimonial exchange setting, when an epistemic agent as a speaker gives testimony of the epistemic agent’s experiences and knowledge but is not awarded the credibility the speaker deserves (Fricker, 2003). Epistemic agents who participate in a testimonial exchange need to overcome bias and prejudice in order to evaluate testimonies with the degree of fairness the testimony deserves (Fricker, 2013; 2016). Hermeneutical injustice occurs when an epistemic agent is unable to make sense and make meaning of their social experiences. Hermeneutical injustice strengthens when the epistemic agent is prevented from gaining access to resources that might help with sense making and meaning making of these social experiences (Dielman, 2012; Fricker, 2016). To ensure that meaning can be made between people and groups of people, there needs to be some shared understandings of the purpose and process of sense making and meaning-making – or a willingness to co-create such shared understandings. Fraser’s norm of Participatory Parity enabled a consideration of the larger world of political and economic systems that give rise to social injustice. In this study, the theories of Fricker and Fraser are used to illuminate experiences of feedback of the five undergraduate student teachers who are the participants in this study and how these translate to epistemic and social injustice. The norm of Participatory Parity is considered where feedback allowed or restricted participants from participating on an equal footing in the feedback process. Narrative inquiry, a research methodology that is used to study experiences, was used to inform research strategies of this study. Participants’ experiences, data collection and organising the narratives demonstrated the dimensions of temporality and space. The thesis includes biographical vignettes for each of the participants in the study, interspersed with data from across all five participants. The key findings of this study show that feedback generally operates at the surface levels of grammar correction. In light of the theoretical lenses of this study, I argue that the feedback experiences they shared generally did not recognise their attempts and the identities and knowledges they brought to the tasks. Because the focus was on superficial correction of the specific task, the feedback failed to create conditions for the (re)distribution of knowledge. At times the feedback exerted power on participants. Because the feedback was generally in the form of one directional correction (with little space for interaction with the feedback or dialogue with the assessor), this caused status subordination of participants in the epistemic spaces of teaching practice. Lastly, the lack of clarity of feedback was harmful to the potential for dialogical feedback. Such feedback caused participants to experience forms of epistemic injustice in the form of hermeneutical injustice where it failed to create conditions for the distribution of knowledge. Feedback also caused participants to experience testimonial injustice where it failed to create conditions for recognising participants’ processes of sense-making and meaning-making in the various assignment tasks. Participatory Parity could not occur because the processes of recognition and redistribution were constrained. Feedback then created fertile conditions of epistemic injustice to occur, and participants were likely to have failed to gain the much needed epistemic access. This study is not the story of bad, uncaring academics; the study acknowledges the context of large classes and heavy workloads in which feedback is or is not given. Rather, this is the story of five women trying to make their way through the university and out into the world as teachers. The study calls for better theorising of feedback and more support for both academics and students to develop feedback literacy so that feedback might serve as a dialogical pedagogic practice that enables epistemic justice. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: Vilakazi, Bella Phetheni
- Date: 2022-04-08
- Subjects: Feedback (Psychology) , Experience , Narrative inquiry (Research method) , Critical thinking , Caring Moral and ethical aspects , Epistemic access
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232599 , vital:50006 , DOI 10.21504/10962/232599
- Description: I am a storyteller. I believe in the power of stories to share experiences and to elucidate thoughts and ideas and to help us to make sense of complex social practices. This thesis includes the stories of five young women who were learning to become teachers. As they shared their stories with me, I share them with you. This study includes their stories of receiving feedback. These stories are structured within the Narrative Inquiry dimensions of temporality, place and context. These dimensions suggest that stories are historical and move through time, stories are shaped by place and the context in which they unfold (Clandinin, 2013). Furthermore, these stories demonstrate how feedback can serve to give access to powerful knowledge and can serve to recognise who our students are and what they bring to the academy (Hordern, 2018). But feedback can also serve to misrecognise. Much has been written and reported about the barriers preventing students from acting on the feedback on their assignment tasks in higher education. In this study, I argue that feedback is a pedagogic practice that can support students to gain epistemic access. Feedback can only achieve this if it makes the expectations explicit for students to make sense of and make meaning for themselves and if it is offered in a dialogical format which recognises the students, their attempts, their identities, and their knowledge. The research question of this study, ‘How do experiences of forms of feedback affect female undergraduate student teachers’ chances of epistemic access?’, is not unusual. There have been many research projects that have been carried out that examine students’ experiences of feedback (for example, Evans, 2013; Basey, Maines, & Francis, 2014; Nicol et al.; 2014; Carless, 2019; Winstone et al., 2021). But I identified a gap where feedback has not, to my knowledge, been studied directly through the lenses of Epistemic Justice towards Parity of Participation. This study interpreted five undergraduate student teachers’ feedback experiences through these lenses. Narrative inquiry enabled me to design this study in ways that foregrounded experience. Data was collected through multiple conversations during which I organised the participants’ life stories of feedback within the dimensions of temporality, place and context, and sociality. Miranda Fricker’s (2007) theory of Epistemic Justice and Fraser’s norm of Parity of Participation (2000) framed this study. I engaged with Fricker and Fraser’s literature meaningfully as a reader and researcher. I established an understanding of how the lenses offered by Fraser and Fricker allowed me to make sense of the literature more generally, in social life and on the pedagogic practice of feedback. Fricker’s theory of Epistemic Justice considers the epistemically unjust, gendered, raced and classed, experiences of epistemic agents. Fricker (2007) draws on two central concepts to account for epistemic injustices: Testimonial Injustice and Hermeneutical Injustice. Fricker (2007; 2003) explains that testimonial injustice occurs within a testimonial exchange setting, when an epistemic agent as a speaker gives testimony of the epistemic agent’s experiences and knowledge but is not awarded the credibility the speaker deserves (Fricker, 2003). Epistemic agents who participate in a testimonial exchange need to overcome bias and prejudice in order to evaluate testimonies with the degree of fairness the testimony deserves (Fricker, 2013; 2016). Hermeneutical injustice occurs when an epistemic agent is unable to make sense and make meaning of their social experiences. Hermeneutical injustice strengthens when the epistemic agent is prevented from gaining access to resources that might help with sense making and meaning making of these social experiences (Dielman, 2012; Fricker, 2016). To ensure that meaning can be made between people and groups of people, there needs to be some shared understandings of the purpose and process of sense making and meaning-making – or a willingness to co-create such shared understandings. Fraser’s norm of Participatory Parity enabled a consideration of the larger world of political and economic systems that give rise to social injustice. In this study, the theories of Fricker and Fraser are used to illuminate experiences of feedback of the five undergraduate student teachers who are the participants in this study and how these translate to epistemic and social injustice. The norm of Participatory Parity is considered where feedback allowed or restricted participants from participating on an equal footing in the feedback process. Narrative inquiry, a research methodology that is used to study experiences, was used to inform research strategies of this study. Participants’ experiences, data collection and organising the narratives demonstrated the dimensions of temporality and space. The thesis includes biographical vignettes for each of the participants in the study, interspersed with data from across all five participants. The key findings of this study show that feedback generally operates at the surface levels of grammar correction. In light of the theoretical lenses of this study, I argue that the feedback experiences they shared generally did not recognise their attempts and the identities and knowledges they brought to the tasks. Because the focus was on superficial correction of the specific task, the feedback failed to create conditions for the (re)distribution of knowledge. At times the feedback exerted power on participants. Because the feedback was generally in the form of one directional correction (with little space for interaction with the feedback or dialogue with the assessor), this caused status subordination of participants in the epistemic spaces of teaching practice. Lastly, the lack of clarity of feedback was harmful to the potential for dialogical feedback. Such feedback caused participants to experience forms of epistemic injustice in the form of hermeneutical injustice where it failed to create conditions for the distribution of knowledge. Feedback also caused participants to experience testimonial injustice where it failed to create conditions for recognising participants’ processes of sense-making and meaning-making in the various assignment tasks. Participatory Parity could not occur because the processes of recognition and redistribution were constrained. Feedback then created fertile conditions of epistemic injustice to occur, and participants were likely to have failed to gain the much needed epistemic access. This study is not the story of bad, uncaring academics; the study acknowledges the context of large classes and heavy workloads in which feedback is or is not given. Rather, this is the story of five women trying to make their way through the university and out into the world as teachers. The study calls for better theorising of feedback and more support for both academics and students to develop feedback literacy so that feedback might serve as a dialogical pedagogic practice that enables epistemic justice. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2022
- Full Text:
- Date Issued: 2022-04-08
Thicket expansion in a vachellia karroo-dominated landscape and its effect on herbaceous communities
- Authors: Khoza, Marina Rindzani
- Date: 2022-04-06
- Subjects: Savanna ecology South Africa , Forbs South Africa , Grasslands South Africa , Herbaceous plants South Africa , Vegetation dynamics South Africa , Forest canopies South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291015 , vital:56808
- Description: Grass and forb species found in savannas are highly diverse, contributing to the structure and function of the savanna system. Where mean annual rainfall is seasonal and high enough to support closed canopy vegetation such as forests or thickets, savannas can exist as an alternative stable state maintained by disturbances such as fire and browsing. Biotic and abiotic processes act on savanna and forest (or thicket) systems maintaining both their tree and herbaceous cover at levels that ensure their persistence in those states. Studies have shown that many semi-arid rangelands in South Africa have undergone a rapid increase in tree cover (of both native and non-native species) over the past several decades. This process of increasing tree cover in semi-arid savannas, termed bush encroachment, results in a biome shift, changing landscapes that were once grasslands with few trees to ones dominated by broad-leaved trees with fewer sun-adapted forbs and grasses. The aim of this study was to investigate the impact of changing woody cover and its associated changes in tree composition, tree canopy structure, light dynamics in the understory and herbaceous community composition on Endwell farm in the Eastern Cape. Canopy cover changes between the years 1949 and 2019 were analysed at 51 sites on the farm and related to historical rainfall patterns. There had been a general increase in tree cover over the past several decades on the farm, and many sites showed a change from open (0-15%) in 1949 to low (1635%), moderate (36-50%) and high (51-100%) canopy cover in 2019. In earlier years most sites had a canopy cover below 50%, and the higher canopy cover values (>65%) occurred in more recent decades. Canopy cover of ~ 50% was found to be rare in each decade. This suggests that ~50% canopy cover maybe a transient, unstable state. The period with the highest rate of canopy cover increase was 2002-2013, and this increase coincided with a high mean annual rainfall 10 years prior to 2002 and a high mean annual rainfall in most years between the 20022013 period. The period between 2002 and 2013 also had the highest number of sites transitioning from lower to higher tree canopy cover classes, indicating that rainfall may have been a factor driving bush encroachment during the past several decades. An increase in canopy cover (a decrease in light transmittance) was accompanied by changes in woody species composition during thicket formation. The low canopy cover (high light transmittance) sites were dominated by Vachellia karroo and Scutia myrtina trees, while high tree cover sites had fewer V. karroo and S. myrtina trees and were rather characterised by an abundance of thicket tree species. Species proportion, NMDS and dendrogram plots indicated that sites with a light transmittance range between 50-100% had similar tree species compositions, different from sites with light transmittances <50%. An increase in tree density was strongly correlated to an increase in canopy cover (from 2019 satellite imagery), density of trees > 3m, maximum height reached by trees, diversity of trees, total canopy volume, total canopy area and leaf area index (LAI), and a decrease in light transmittance. A structural equation model (SEM) was used to explore the relationships between canopy characteristics (maximum canopy area, canopy volume, tree diversity, density of trees, density of trees >3m, individual trees and maximum canopy height), aerial canopy cover in 2019, and light transmittance. The model explained 73% of the variation in light transmittance, mostly via the direct effect of canopy characteristics. Canopy characteristics had a strong influence on both aerial cover in 2019 and directly on light transmittance, but canopy cover in 2019 had a weak influence on light transmittance. The herbaceous layer was rich and dominated by C4 grasses such as Eragrostis plana, Sporobolus fimbriatus, Themeda triandra and Digitaria eriantha) and forbs including Hibiscus aethiopicus, Helichrysum dregeanum, Helichrysum nudifolium and Gerbera viridifolia at low canopy cover sites with high light transmittance. In contrast, high tree cover sites had fewer herbaceous species in general. Grass and forb species characteristic of these sites high canopy cover sites were Panicum maximum, Loudetia flavida, Pellaea viridis and Cyperus spp. Different sites with low light transmittance (<50%) had similar herbaceous species composition. Basal cover, richness, abundance and diversity of herbaceous plants decreased significantly with an increase in tree density, density of trees >3 m, canopy volume, canopy area, canopy cover, LAI, and increased significantly with increasing light transmittance. Most grasses had their highest densities at LAI <0.5, which was estimated to correspond to ~75% light transmittance and ~38% canopy cover and then started to decline thereafter. Herbaceous species basal cover was also highest at LAI <0.5. An SEM model indicated that herbaceous diversity, basal cover and richness responded both to light availability and to the structure of the woody vegetation directly (R2 = 0.53). While the effect of light transmittance on herbaceous communities was strong (0.41), there was little difference between the effect of light transmittance and canopy characteristics (-0.35) on herbaceous communities. Two possible threshold points, relating to two types of transitions in vegetation structure, could be deduced from this study. The first threshold occurred at canopy cover ~ 40% (LAI < ~ 0.5, light transmittance ~ 75%), at which point many of the common herbaceous species, including the dominant C4 grasses, began to decline in abundance while the composition remained characteristic of the savanna state. A canopy cover of less than ~ 40% at a site provides a suitable state for a high abundance of grass and forb species which help maintain an open system by facilitating fires. The second threshold marked a compositional shift between savanna and closed-canopy vegetation states. Savanna species (trees, grasses and forbs) dominated at high light transmittances (>50%) and were significantly reduced at low light transmittances (< 50%), indicating a possible species composition threshold at ~50% light transmittance at which a savanna state switches to a thicket (LAI ~ 1 and canopy cover ~70%). This point indicated the point where there was a significant difference in both tree and herbaceous plant compositions, with a marked reduction in the occurrence of C4 grasses at light transmittance <50%. Fire is supressed when the C4 grass layer is lost, and further thicket encroachment will take place causing complete canopy closure. Land managers in this system should start becoming concerned about a reduction in grass biomass when canopy cover reaches about 40% and would have to reduce tree cover before the threshold of 50% light transmittance (70% canopy cover from aerial photos) is reached to maintain a savanna system. , Thesis (MSc) -- Faculty of Science, Botany, 2022
- Full Text:
- Date Issued: 2022-04-06
Thicket expansion in a vachellia karroo-dominated landscape and its effect on herbaceous communities
- Authors: Khoza, Marina Rindzani
- Date: 2022-04-06
- Subjects: Savanna ecology South Africa , Forbs South Africa , Grasslands South Africa , Herbaceous plants South Africa , Vegetation dynamics South Africa , Forest canopies South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291015 , vital:56808
- Description: Grass and forb species found in savannas are highly diverse, contributing to the structure and function of the savanna system. Where mean annual rainfall is seasonal and high enough to support closed canopy vegetation such as forests or thickets, savannas can exist as an alternative stable state maintained by disturbances such as fire and browsing. Biotic and abiotic processes act on savanna and forest (or thicket) systems maintaining both their tree and herbaceous cover at levels that ensure their persistence in those states. Studies have shown that many semi-arid rangelands in South Africa have undergone a rapid increase in tree cover (of both native and non-native species) over the past several decades. This process of increasing tree cover in semi-arid savannas, termed bush encroachment, results in a biome shift, changing landscapes that were once grasslands with few trees to ones dominated by broad-leaved trees with fewer sun-adapted forbs and grasses. The aim of this study was to investigate the impact of changing woody cover and its associated changes in tree composition, tree canopy structure, light dynamics in the understory and herbaceous community composition on Endwell farm in the Eastern Cape. Canopy cover changes between the years 1949 and 2019 were analysed at 51 sites on the farm and related to historical rainfall patterns. There had been a general increase in tree cover over the past several decades on the farm, and many sites showed a change from open (0-15%) in 1949 to low (1635%), moderate (36-50%) and high (51-100%) canopy cover in 2019. In earlier years most sites had a canopy cover below 50%, and the higher canopy cover values (>65%) occurred in more recent decades. Canopy cover of ~ 50% was found to be rare in each decade. This suggests that ~50% canopy cover maybe a transient, unstable state. The period with the highest rate of canopy cover increase was 2002-2013, and this increase coincided with a high mean annual rainfall 10 years prior to 2002 and a high mean annual rainfall in most years between the 20022013 period. The period between 2002 and 2013 also had the highest number of sites transitioning from lower to higher tree canopy cover classes, indicating that rainfall may have been a factor driving bush encroachment during the past several decades. An increase in canopy cover (a decrease in light transmittance) was accompanied by changes in woody species composition during thicket formation. The low canopy cover (high light transmittance) sites were dominated by Vachellia karroo and Scutia myrtina trees, while high tree cover sites had fewer V. karroo and S. myrtina trees and were rather characterised by an abundance of thicket tree species. Species proportion, NMDS and dendrogram plots indicated that sites with a light transmittance range between 50-100% had similar tree species compositions, different from sites with light transmittances <50%. An increase in tree density was strongly correlated to an increase in canopy cover (from 2019 satellite imagery), density of trees > 3m, maximum height reached by trees, diversity of trees, total canopy volume, total canopy area and leaf area index (LAI), and a decrease in light transmittance. A structural equation model (SEM) was used to explore the relationships between canopy characteristics (maximum canopy area, canopy volume, tree diversity, density of trees, density of trees >3m, individual trees and maximum canopy height), aerial canopy cover in 2019, and light transmittance. The model explained 73% of the variation in light transmittance, mostly via the direct effect of canopy characteristics. Canopy characteristics had a strong influence on both aerial cover in 2019 and directly on light transmittance, but canopy cover in 2019 had a weak influence on light transmittance. The herbaceous layer was rich and dominated by C4 grasses such as Eragrostis plana, Sporobolus fimbriatus, Themeda triandra and Digitaria eriantha) and forbs including Hibiscus aethiopicus, Helichrysum dregeanum, Helichrysum nudifolium and Gerbera viridifolia at low canopy cover sites with high light transmittance. In contrast, high tree cover sites had fewer herbaceous species in general. Grass and forb species characteristic of these sites high canopy cover sites were Panicum maximum, Loudetia flavida, Pellaea viridis and Cyperus spp. Different sites with low light transmittance (<50%) had similar herbaceous species composition. Basal cover, richness, abundance and diversity of herbaceous plants decreased significantly with an increase in tree density, density of trees >3 m, canopy volume, canopy area, canopy cover, LAI, and increased significantly with increasing light transmittance. Most grasses had their highest densities at LAI <0.5, which was estimated to correspond to ~75% light transmittance and ~38% canopy cover and then started to decline thereafter. Herbaceous species basal cover was also highest at LAI <0.5. An SEM model indicated that herbaceous diversity, basal cover and richness responded both to light availability and to the structure of the woody vegetation directly (R2 = 0.53). While the effect of light transmittance on herbaceous communities was strong (0.41), there was little difference between the effect of light transmittance and canopy characteristics (-0.35) on herbaceous communities. Two possible threshold points, relating to two types of transitions in vegetation structure, could be deduced from this study. The first threshold occurred at canopy cover ~ 40% (LAI < ~ 0.5, light transmittance ~ 75%), at which point many of the common herbaceous species, including the dominant C4 grasses, began to decline in abundance while the composition remained characteristic of the savanna state. A canopy cover of less than ~ 40% at a site provides a suitable state for a high abundance of grass and forb species which help maintain an open system by facilitating fires. The second threshold marked a compositional shift between savanna and closed-canopy vegetation states. Savanna species (trees, grasses and forbs) dominated at high light transmittances (>50%) and were significantly reduced at low light transmittances (< 50%), indicating a possible species composition threshold at ~50% light transmittance at which a savanna state switches to a thicket (LAI ~ 1 and canopy cover ~70%). This point indicated the point where there was a significant difference in both tree and herbaceous plant compositions, with a marked reduction in the occurrence of C4 grasses at light transmittance <50%. Fire is supressed when the C4 grass layer is lost, and further thicket encroachment will take place causing complete canopy closure. Land managers in this system should start becoming concerned about a reduction in grass biomass when canopy cover reaches about 40% and would have to reduce tree cover before the threshold of 50% light transmittance (70% canopy cover from aerial photos) is reached to maintain a savanna system. , Thesis (MSc) -- Faculty of Science, Botany, 2022
- Full Text:
- Date Issued: 2022-04-06
The design of a football Academy in Gelvandale, Gqeberha: Sports as a tool for social intergration
- Authors: Sauls,Eldridge
- Date: 2021-12
- Subjects: Sports facilities --South Africa-- Port Elizabeth -- Designs and plans , City planning--South Africa --Port Elizabeth -- Gelvandale
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58628 , vital:59969
- Description: In South African townships, youth from disadvantaged groups, lack suf ficient social and sporting facilities to spend their time. This situation exists in the Gelvandale township of Gqeberha. This treatise unfolds through the author’s interest in Gelvandale out of concern for how poorly the sense of urban space is, within the township context. The treatise will explore the nature of Gelvandale from a macro scale towards a precinct scale regarding connectivity, location, spatial organi sation, activities, the built fabric, and socio-economic conditions. Through exploration, it was identified that Gelvandale functions as an enclaved system within the context of Gqeberha. The issues affecting Gelvandale were identified as the dispersal of activities, urban sprawl, fragmentation, and lack of urban legibility. It was identified that dispersed activities are one of the major contribu tors to the poor urban environment. This treatise investigates the significance of a football academy in Gel vandale, and how it could have an influence on society and the built form. Addressing this issue will be an effective way to improve the ur ban environment, to provide an urban and architectural response in an attempt to reduce the dispersal activities in Gelvandale. Through the exploration of the nature of dispersed activities in Gelvandale, it was observed that most activities are dispersed throughout Gelvandale, indicating that there are areas with a higher cluster of certain activities. In response, a pro posed strategy had been conceptualised to propose the consolidation of activities that are connected through pedestrian movement paths. Gelvandale had been identified as having a high intensity of sporting facilities and is therefore been proposed as a concentrated facility for recreational and sporting activities. An appropriate site was then selected for the proposed devel opment. The resultant outcome of the program was a Football Academy. The conclusion was based on the conceptual urban strategy and the needs of the community. It was established that the facility should function as a major structural element in Gelvandale, leading to the investigation of positive urban spaces through the in terrogation of precedents. The cues from the interrogation were used to assist in structuring the nature of the proposed facility responding to the public realm and its urban and architectural issues. , Thesis (MArch) -- Faculty of Engineering, the Built Environment and Technology, School of Architecture, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Sauls,Eldridge
- Date: 2021-12
- Subjects: Sports facilities --South Africa-- Port Elizabeth -- Designs and plans , City planning--South Africa --Port Elizabeth -- Gelvandale
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58628 , vital:59969
- Description: In South African townships, youth from disadvantaged groups, lack suf ficient social and sporting facilities to spend their time. This situation exists in the Gelvandale township of Gqeberha. This treatise unfolds through the author’s interest in Gelvandale out of concern for how poorly the sense of urban space is, within the township context. The treatise will explore the nature of Gelvandale from a macro scale towards a precinct scale regarding connectivity, location, spatial organi sation, activities, the built fabric, and socio-economic conditions. Through exploration, it was identified that Gelvandale functions as an enclaved system within the context of Gqeberha. The issues affecting Gelvandale were identified as the dispersal of activities, urban sprawl, fragmentation, and lack of urban legibility. It was identified that dispersed activities are one of the major contribu tors to the poor urban environment. This treatise investigates the significance of a football academy in Gel vandale, and how it could have an influence on society and the built form. Addressing this issue will be an effective way to improve the ur ban environment, to provide an urban and architectural response in an attempt to reduce the dispersal activities in Gelvandale. Through the exploration of the nature of dispersed activities in Gelvandale, it was observed that most activities are dispersed throughout Gelvandale, indicating that there are areas with a higher cluster of certain activities. In response, a pro posed strategy had been conceptualised to propose the consolidation of activities that are connected through pedestrian movement paths. Gelvandale had been identified as having a high intensity of sporting facilities and is therefore been proposed as a concentrated facility for recreational and sporting activities. An appropriate site was then selected for the proposed devel opment. The resultant outcome of the program was a Football Academy. The conclusion was based on the conceptual urban strategy and the needs of the community. It was established that the facility should function as a major structural element in Gelvandale, leading to the investigation of positive urban spaces through the in terrogation of precedents. The cues from the interrogation were used to assist in structuring the nature of the proposed facility responding to the public realm and its urban and architectural issues. , Thesis (MArch) -- Faculty of Engineering, the Built Environment and Technology, School of Architecture, 2021
- Full Text:
- Date Issued: 2021-12
The use of ambient seismic noise to investigate internal changes in a tailings storage facility and to image the subsurface geology in the Cradock area of the Eastern Cape
- Authors: Kunjwa, Thulisile
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53642 , vital:45690
- Description: Passive seismic interferometry is a process by which ambient noise data recorded at different seismic stations can be cross-correlated to estimate Green's functions. In the past, both surface waves and body waves have successfully been extracted by cross-correlation of ambient noise data on both regional and global scales. Recent advancements in ambient seismic noise techniques have the potential to provide new methods for subsurface imaging and monitoring. The ambient noise data processing procedure divides into four principal phases: (1) single station data preparation, (2) cross-correlation and temporal stacking, (3) measurement of dispersion curves and (4) inversion of dispersion curves to obtain 1-D shear wave profiles and computation of 2-D shear wave velocity cross-section. The purpose of this study is to investigate whether ambient seismic noise can be used to image and detect internal changes within a mine tailings dam wall and to image the subsurface geology of part of the Eastern Cape Karoo near Cradock. In the first experiment, the investigation consisted of continuous ambient noise data recordings over a period of 3 days with 20 three-component short period geophones. The geophones were deployed over a survey wall of roughly 100 m in length at the Harmony Gold mine tailings dam in Welkom. In the second experiment, the investigation consisted of data recordings over a period of 35 days. The geophones were deployed in Cradock. The first phase of the data processing procedure included de-trending, de-meaning and band-pass filtering the data. This was done to ensure that any long period trends associated with instrument glitches are removed from the data. A spectrogram was then computed to view the spectrum of frequencies in the signal and to check if the filter that was designed was able to cut off the unwanted frequencies. The horizontal and vertical components of the ambient noise data were cross-correlated and picked between sensor pairs to create surface wave dispersion curves. Subsequently, the dispersion curves were inverted to estimate the shear wave velocity of the dam wall and subsurface as a function of depth. The computed cross sections of shear wave velocity indicated a low-velocity zone between 2 and 10 m below the surface on the dam wall, this suggested that the phreatic surface is much closer to surface in this area. In the second experiment, the interpolated shear wave velocity profiles indicated that there is a layer of low velocity zone between depths 250 to 300 m below the surface. The cross-correlations were also used to compute group velocity maps from periods 1.5 seconds to 30 seconds. The group velocity maps showed various high and low velocity anomalies. The high velocity zones observed on the eastern section of the map were interpreted as evidence of dolerite intrusions. The low velocity zones observed in the western and southern sections of the map interpreted as Karoo sediments that belong to the Adelaide Subgroup which is dominated by mudstones. , Thesis (MSc) -- Faculty of Science, Department of Geosciences (Geology and Geography), 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Kunjwa, Thulisile
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53642 , vital:45690
- Description: Passive seismic interferometry is a process by which ambient noise data recorded at different seismic stations can be cross-correlated to estimate Green's functions. In the past, both surface waves and body waves have successfully been extracted by cross-correlation of ambient noise data on both regional and global scales. Recent advancements in ambient seismic noise techniques have the potential to provide new methods for subsurface imaging and monitoring. The ambient noise data processing procedure divides into four principal phases: (1) single station data preparation, (2) cross-correlation and temporal stacking, (3) measurement of dispersion curves and (4) inversion of dispersion curves to obtain 1-D shear wave profiles and computation of 2-D shear wave velocity cross-section. The purpose of this study is to investigate whether ambient seismic noise can be used to image and detect internal changes within a mine tailings dam wall and to image the subsurface geology of part of the Eastern Cape Karoo near Cradock. In the first experiment, the investigation consisted of continuous ambient noise data recordings over a period of 3 days with 20 three-component short period geophones. The geophones were deployed over a survey wall of roughly 100 m in length at the Harmony Gold mine tailings dam in Welkom. In the second experiment, the investigation consisted of data recordings over a period of 35 days. The geophones were deployed in Cradock. The first phase of the data processing procedure included de-trending, de-meaning and band-pass filtering the data. This was done to ensure that any long period trends associated with instrument glitches are removed from the data. A spectrogram was then computed to view the spectrum of frequencies in the signal and to check if the filter that was designed was able to cut off the unwanted frequencies. The horizontal and vertical components of the ambient noise data were cross-correlated and picked between sensor pairs to create surface wave dispersion curves. Subsequently, the dispersion curves were inverted to estimate the shear wave velocity of the dam wall and subsurface as a function of depth. The computed cross sections of shear wave velocity indicated a low-velocity zone between 2 and 10 m below the surface on the dam wall, this suggested that the phreatic surface is much closer to surface in this area. In the second experiment, the interpolated shear wave velocity profiles indicated that there is a layer of low velocity zone between depths 250 to 300 m below the surface. The cross-correlations were also used to compute group velocity maps from periods 1.5 seconds to 30 seconds. The group velocity maps showed various high and low velocity anomalies. The high velocity zones observed on the eastern section of the map were interpreted as evidence of dolerite intrusions. The low velocity zones observed in the western and southern sections of the map interpreted as Karoo sediments that belong to the Adelaide Subgroup which is dominated by mudstones. , Thesis (MSc) -- Faculty of Science, Department of Geosciences (Geology and Geography), 2021
- Full Text:
- Date Issued: 2021-12
The effects of temperature and exploitation on the behaviour of red roman Chrysoblephus laticeps (Sparidae) at baited video stations
- Authors: Mataboge, Bontle Boitumelo
- Date: 2022-04-06
- Subjects: Marine resources conservation South Africa Agulhas , Sparidae Effect of temperature on South Africa Agulhas , Sparidae Climatic factors South Africa Agulhas , Sparidae Effect of fishing on South Africa Agulhas , Sparidae Effect of human beings on South Africa Agulhas , Sparidae Behavior South Africa Agulhas , Overfishing South Africa Agulhas , Underwater videography in wildlife monitoring South Africa Agulhas , Red roman (Chrysoblephus laticeps)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291140 , vital:56823
- Description: Marine environments are experiencing rapidly increasing temperatures, sea levels and acidification and higher frequencies and magnitudes of extreme weather events as a result of climate change. In the Agulhas Ecoregion of South Africa, there has been an increase in the frequency and intensity of upwelling events. Upwelling events result in rapid and large decreases in water temperature which can persist for several days. Variation in water temperature is known to impact the metabolic rate of fish (which are ectotherms) and in turn their activity patterns. To promote fitness related traits, the metabolic rate of fish is maximised at a specific temperature range. Outside of this optimal temperature range, the capacity of fish to perform aerobically declines. Therefore, it is expected that an increase in upwelling may place the fish under significant physiological stress. The effects of climate change can be compounded by the effects of fisheries-induced evolution; the microevolution of a fish population due to the artificial selection of certain biological traits by fishing practices. Passive fishing gears preferentially remove large (older) and bold individuals, causing reductions in population size, genetic diversity and fecundity as well as size and age truncation and the loss of large, bold and dominant phenotypes in fish populations. These demographic changes affect the adaptive capacity of fish and exploited populations are expected to be less resilient to climate variability and long-term temperature change. The resilience of fish is largely dependent on their physiological attributes, particularly their metabolic rate. Theoretically, fish with broader aerobic scope (defined as the difference between an individual’s maximum metabolic rate and standard metabolic rate) will be more tolerant to the impacts of climate change as they have energy available for adaptation. Recent respirometry and accelerometry studies suggest that populations of the endemic southern African linefish Chrysoblephus laticeps (red roman) from inside marine protected areas (MPAs) have higher metabolic rates and broader aerobic scope compared to those found outside of MPAs, particularly at thermal extremes. As C. laticeps are highly resident it is possible that fish populations protected within well-established MPAs may be more resilient to the physiological stresses caused by upwelling if they are able to maintain their activity levels despite changing temperatures. Behaviour is a proxy that can be used to infer metabolism as behaviours have associated metabolic costs and benefits. Behaviour is also a trait that can be altered by passive fishing practices which preferentially extract more active and bold individuals. Given this context, the aim of this thesis was to determine the effects of short-term thermal variability on the population structure and behaviour of C. laticeps and whether these effects differed between protected and exploited populations. Baited remote underwater stereo-video systems (stereo-BRUVs) were used to observe C. laticeps inside two MPAs (Tsitsikamma and Goukamma) and at two exploited sites (Port Elizabeth and Cape St. Francis) over the temperature range 10-18 °C. The relative abundance, size and relevant behaviours of C. laticeps were recorded. The relative abundance (MaxN) of C. laticeps was not significantly higher inside the MPAs compared to the exploited sites. The size of C. laticeps did not vary significantly by protection level either. However, the mean size of C. laticeps was considerably smaller at Port Elizabeth compared to the three other locations. There was a notable absence of large C. laticeps size classes at Port Elizabeth. The effect of water temperature on relative abundance was only seen in the exploited areas, where temperature and abundance were positively correlated. This was not the case in the protected areas where C. laticeps abundance remained roughly consistent. Generally, the effect of temperature on all measured behaviours was consistent across protection levels. An exception was that the feeding rate at Tsitsikamma MPA was significantly higher than at Cape St. Francis at temperatures below 11.5 °C. Temperature had a significant effect on the time taken for the first individual to appear in the field of view. This time shortened with increasing temperature, regardless of protection level. This was likely a result of the metabolic constraints placed on individuals by low waters temperatures and individuals would be able to pursue the bait more readily at higher temperatures. However, there was no evidence of greater metabolic scope from the C. laticeps individuals observed in the MPAs, relative to the exploited areas. Individual size and the presence of conspecifics were also found to significantly influence behaviour. Generally, size had a positive relationship with behaviour, with larger individuals more likely to feed on the bait, chase other fish from the bait (only in the MPAs) and spend more time in the field of view. The higher displays of aggression in MPAs may be an indication of fishing practices having removed bold and dominant individuals at the exploited sites. The probability of fleeing and the feeding rates of individuals increased with increasing numbers of conspecifics, suggesting that C. laticeps behaviour is influenced by intraspecific competition. Overall, this thesis did not find strong evidence that C. laticeps from MPAs performed better than C. laticeps from exploited areas, even at low temperatures. Behavioural responses to temperature were highly variable across locations and this may be attributed to high behavioural phenotypic diversity among individuals. Environmental stressors, such as temperature changes, can illicit very different behavioural responses among individuals in a population. It is also possible that C. laticeps from the exploited areas have the same genetic predispositions to physiological stress as the individuals in the MPAs due to spillover and larval recruitment from the MPAs. Indeed, genetic studies find that all C. laticeps population in South African represent a single well-mixed genetic stock. It is likely that greater sampling effort is required to resolve the patterns in behaviour between exploited and protected populations. Nonetheless, given the influence of size on behaviour, the smaller size of C. laticeps at Port Elizabeth may be cause for concern regarding the vulnerability of future populations to ongoing climate change. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Mataboge, Bontle Boitumelo
- Date: 2022-04-06
- Subjects: Marine resources conservation South Africa Agulhas , Sparidae Effect of temperature on South Africa Agulhas , Sparidae Climatic factors South Africa Agulhas , Sparidae Effect of fishing on South Africa Agulhas , Sparidae Effect of human beings on South Africa Agulhas , Sparidae Behavior South Africa Agulhas , Overfishing South Africa Agulhas , Underwater videography in wildlife monitoring South Africa Agulhas , Red roman (Chrysoblephus laticeps)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291140 , vital:56823
- Description: Marine environments are experiencing rapidly increasing temperatures, sea levels and acidification and higher frequencies and magnitudes of extreme weather events as a result of climate change. In the Agulhas Ecoregion of South Africa, there has been an increase in the frequency and intensity of upwelling events. Upwelling events result in rapid and large decreases in water temperature which can persist for several days. Variation in water temperature is known to impact the metabolic rate of fish (which are ectotherms) and in turn their activity patterns. To promote fitness related traits, the metabolic rate of fish is maximised at a specific temperature range. Outside of this optimal temperature range, the capacity of fish to perform aerobically declines. Therefore, it is expected that an increase in upwelling may place the fish under significant physiological stress. The effects of climate change can be compounded by the effects of fisheries-induced evolution; the microevolution of a fish population due to the artificial selection of certain biological traits by fishing practices. Passive fishing gears preferentially remove large (older) and bold individuals, causing reductions in population size, genetic diversity and fecundity as well as size and age truncation and the loss of large, bold and dominant phenotypes in fish populations. These demographic changes affect the adaptive capacity of fish and exploited populations are expected to be less resilient to climate variability and long-term temperature change. The resilience of fish is largely dependent on their physiological attributes, particularly their metabolic rate. Theoretically, fish with broader aerobic scope (defined as the difference between an individual’s maximum metabolic rate and standard metabolic rate) will be more tolerant to the impacts of climate change as they have energy available for adaptation. Recent respirometry and accelerometry studies suggest that populations of the endemic southern African linefish Chrysoblephus laticeps (red roman) from inside marine protected areas (MPAs) have higher metabolic rates and broader aerobic scope compared to those found outside of MPAs, particularly at thermal extremes. As C. laticeps are highly resident it is possible that fish populations protected within well-established MPAs may be more resilient to the physiological stresses caused by upwelling if they are able to maintain their activity levels despite changing temperatures. Behaviour is a proxy that can be used to infer metabolism as behaviours have associated metabolic costs and benefits. Behaviour is also a trait that can be altered by passive fishing practices which preferentially extract more active and bold individuals. Given this context, the aim of this thesis was to determine the effects of short-term thermal variability on the population structure and behaviour of C. laticeps and whether these effects differed between protected and exploited populations. Baited remote underwater stereo-video systems (stereo-BRUVs) were used to observe C. laticeps inside two MPAs (Tsitsikamma and Goukamma) and at two exploited sites (Port Elizabeth and Cape St. Francis) over the temperature range 10-18 °C. The relative abundance, size and relevant behaviours of C. laticeps were recorded. The relative abundance (MaxN) of C. laticeps was not significantly higher inside the MPAs compared to the exploited sites. The size of C. laticeps did not vary significantly by protection level either. However, the mean size of C. laticeps was considerably smaller at Port Elizabeth compared to the three other locations. There was a notable absence of large C. laticeps size classes at Port Elizabeth. The effect of water temperature on relative abundance was only seen in the exploited areas, where temperature and abundance were positively correlated. This was not the case in the protected areas where C. laticeps abundance remained roughly consistent. Generally, the effect of temperature on all measured behaviours was consistent across protection levels. An exception was that the feeding rate at Tsitsikamma MPA was significantly higher than at Cape St. Francis at temperatures below 11.5 °C. Temperature had a significant effect on the time taken for the first individual to appear in the field of view. This time shortened with increasing temperature, regardless of protection level. This was likely a result of the metabolic constraints placed on individuals by low waters temperatures and individuals would be able to pursue the bait more readily at higher temperatures. However, there was no evidence of greater metabolic scope from the C. laticeps individuals observed in the MPAs, relative to the exploited areas. Individual size and the presence of conspecifics were also found to significantly influence behaviour. Generally, size had a positive relationship with behaviour, with larger individuals more likely to feed on the bait, chase other fish from the bait (only in the MPAs) and spend more time in the field of view. The higher displays of aggression in MPAs may be an indication of fishing practices having removed bold and dominant individuals at the exploited sites. The probability of fleeing and the feeding rates of individuals increased with increasing numbers of conspecifics, suggesting that C. laticeps behaviour is influenced by intraspecific competition. Overall, this thesis did not find strong evidence that C. laticeps from MPAs performed better than C. laticeps from exploited areas, even at low temperatures. Behavioural responses to temperature were highly variable across locations and this may be attributed to high behavioural phenotypic diversity among individuals. Environmental stressors, such as temperature changes, can illicit very different behavioural responses among individuals in a population. It is also possible that C. laticeps from the exploited areas have the same genetic predispositions to physiological stress as the individuals in the MPAs due to spillover and larval recruitment from the MPAs. Indeed, genetic studies find that all C. laticeps population in South African represent a single well-mixed genetic stock. It is likely that greater sampling effort is required to resolve the patterns in behaviour between exploited and protected populations. Nonetheless, given the influence of size on behaviour, the smaller size of C. laticeps at Port Elizabeth may be cause for concern regarding the vulnerability of future populations to ongoing climate change. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04-06
Administrative justice and the implementation of the reconstruction and development program in Berlin Town, Eastern Cape
- Authors: Makie, Fundiswa
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54460 , vital:46577
- Description: Housing delivery in South Africa is a crucial and topical issue affecting many citizens. The primary objective of the study was to determine the role of administrative justice in the implementation of the Reconstructive and Development Programme (RDP) in Berlin Town, in the province of the Eastern Cape in South Africa. In addition, the aim of this study was to explore the challenges of RDP housing in the study area, as a way of probing whether housing needs were being met. The study was conducted using a qualitative research methodology in gathering data from Berlin Town residents, Buffalo City Metropolitan Municipality staff and Berlin Town councillors. The data analysis revealed that respondents affirmed the importance of administrative justice and the effective implementation of the RDP with regard to housing. Based on the findings of the study, the researcher recommends that the Buffalo City Metropolitan Municipality prioritise the full implementation of the Integrated Development Plan (IDP) in dealing with the housing backlog and challenges in Berlin Town. Moreover, the findings of this study revealed that it is possible to highlight specific recommendations that can be used by various other local municipalities. Thus, the research study showed that efficient local municipal operations have a direct impact on the delivery of RDP houses. Relating to ethical considerations, the researcher ensured that all the requirements for credible research were met throughout the study. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Makie, Fundiswa
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54460 , vital:46577
- Description: Housing delivery in South Africa is a crucial and topical issue affecting many citizens. The primary objective of the study was to determine the role of administrative justice in the implementation of the Reconstructive and Development Programme (RDP) in Berlin Town, in the province of the Eastern Cape in South Africa. In addition, the aim of this study was to explore the challenges of RDP housing in the study area, as a way of probing whether housing needs were being met. The study was conducted using a qualitative research methodology in gathering data from Berlin Town residents, Buffalo City Metropolitan Municipality staff and Berlin Town councillors. The data analysis revealed that respondents affirmed the importance of administrative justice and the effective implementation of the RDP with regard to housing. Based on the findings of the study, the researcher recommends that the Buffalo City Metropolitan Municipality prioritise the full implementation of the Integrated Development Plan (IDP) in dealing with the housing backlog and challenges in Berlin Town. Moreover, the findings of this study revealed that it is possible to highlight specific recommendations that can be used by various other local municipalities. Thus, the research study showed that efficient local municipal operations have a direct impact on the delivery of RDP houses. Relating to ethical considerations, the researcher ensured that all the requirements for credible research were met throughout the study. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text:
- Date Issued: 2021-12
The work In fishing Convention as an Instrument to combat forced labour on fishing vessels: A South African perspective
- Authors: Hlazo,Nonhlanhla
- Date: 2021-12
- Subjects: Fishery law and legislation , Forced labor – South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55877 , vital:54396
- Description: This thesis sets to analyse the provisions of the Work in Fishing Convention (WFC), No. 188 of 2007 and the South African Merchant Shipping Act 57 of 1951 (MSA). This analysis focuses on the regulation of the legal aspects of common practices that result in forced labour and provisions which serve as a deterrence to potential “threats of punishment” used to perpetuate forced labour on fishing vessels. The aim of this analysis is to determine whether South Africa complies with its duties in terms of the WFC. In the process of this analysis, this thesis aims to identify gaps in the MSA that allow for this appalling practice to continue and provide recommendations for amendments to the Merchant Shipping Bill (MSB) based on the identified discrepancies between the MSA and the WFC. Chapter one is an introductory chapter which explains that two elements must be present for a situation to amount to forced labour, namely “involuntariness” and the “threat of penalty.” Chapter two examines South Africa’ s jurisdiction to criminalise, investigate and try fisheries crimes on fishing vessels in different maritime zones. The aim of this examination is to determine whether South Africa has the jurisdiction to criminalise forced labour on fishing vessels in different maritime zones. It is concluded that, while South Africa’s enforcement and adjudicative jurisdiction may be limited in some maritime zones, South Africa has the jurisdiction to criminalise forced labour as a coastal State, flag State, personal State and a port State. Chapter three focuses on global and regional legal instruments to combat forced labour and establishes the significant role of the WFC in combatting forced labour on fishing vessels specifically. It is further concluded that, provided the provisions of the proposed MSB do not change, South Africa currently complies with its duties in accordance with the WFC and goes beyond what is required in some respects. However, South Africa does not comply with its obligation to regulate the recruitment and placement agencies for fishers. This leaves fishers in South Africa vulnerable to coercion by unscrupulous recruitment agencies. It is suggested that the provisions of the WFC relating to the recruitment and placement of fishers can be given effect in South Africa by either amending the current Seafarer Recruitment and Placement Regulations to apply to fishers or by drafting new Merchant Shipping (Fisher Recruitment and Placement) Regulations, which give effect to the WFC in line with the existing Seafarer Recruitment and Placement Regulations and promulgating them in terms of the MSA or its successor. , Thesis (LLD) -- Faculty of Law, School Public Law, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Hlazo,Nonhlanhla
- Date: 2021-12
- Subjects: Fishery law and legislation , Forced labor – South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55877 , vital:54396
- Description: This thesis sets to analyse the provisions of the Work in Fishing Convention (WFC), No. 188 of 2007 and the South African Merchant Shipping Act 57 of 1951 (MSA). This analysis focuses on the regulation of the legal aspects of common practices that result in forced labour and provisions which serve as a deterrence to potential “threats of punishment” used to perpetuate forced labour on fishing vessels. The aim of this analysis is to determine whether South Africa complies with its duties in terms of the WFC. In the process of this analysis, this thesis aims to identify gaps in the MSA that allow for this appalling practice to continue and provide recommendations for amendments to the Merchant Shipping Bill (MSB) based on the identified discrepancies between the MSA and the WFC. Chapter one is an introductory chapter which explains that two elements must be present for a situation to amount to forced labour, namely “involuntariness” and the “threat of penalty.” Chapter two examines South Africa’ s jurisdiction to criminalise, investigate and try fisheries crimes on fishing vessels in different maritime zones. The aim of this examination is to determine whether South Africa has the jurisdiction to criminalise forced labour on fishing vessels in different maritime zones. It is concluded that, while South Africa’s enforcement and adjudicative jurisdiction may be limited in some maritime zones, South Africa has the jurisdiction to criminalise forced labour as a coastal State, flag State, personal State and a port State. Chapter three focuses on global and regional legal instruments to combat forced labour and establishes the significant role of the WFC in combatting forced labour on fishing vessels specifically. It is further concluded that, provided the provisions of the proposed MSB do not change, South Africa currently complies with its duties in accordance with the WFC and goes beyond what is required in some respects. However, South Africa does not comply with its obligation to regulate the recruitment and placement agencies for fishers. This leaves fishers in South Africa vulnerable to coercion by unscrupulous recruitment agencies. It is suggested that the provisions of the WFC relating to the recruitment and placement of fishers can be given effect in South Africa by either amending the current Seafarer Recruitment and Placement Regulations to apply to fishers or by drafting new Merchant Shipping (Fisher Recruitment and Placement) Regulations, which give effect to the WFC in line with the existing Seafarer Recruitment and Placement Regulations and promulgating them in terms of the MSA or its successor. , Thesis (LLD) -- Faculty of Law, School Public Law, 2021
- Full Text:
- Date Issued: 2021-12
In-vitroevaluation of bridelia ferruginea extract gold nanoparticles for the treatment of colon cancer
- Zosela, Itumeleng, Davids, Hajierah
- Authors: Zosela, Itumeleng , Davids, Hajierah
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54124 , vital:46311
- Description: Colorectal cancer (CRC) has become a health burden, being the third common cancer worldwide. Treatment of colorectal cancer is very important to manage the high prevalence rate of this disease. The available treatments for CRC have their drawbacks and side effects. Available treatments of colon cancer include surgery, chemotherapy, and radiation. Due to the side effects associated with these treatments, alternative treatments that pose less side effects are being developed worldwide. Nanotechnologies have gained global consideration due to their potential to improve the current standards and techniques for the diagnosis and treatment. The use of plants for synthesis of gold nanoparticles has opened a new venture of synthesizing environmentally friendly and cost-effective nanoparticles which possess great properties for CRC treatment. The aim of this study was to investigate the use of green synthesized AuNPs from Bridelia ferruginea for potential cancer treatment. In this work study gold nanoparticles were synthesized utilizing Bridelia ferruginea stem bark extract. The nanoparticles were characterized using UV–Vis spectroscopy, Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FTIR) and High-Resolution Transmission Electron Microscopy (HRTEM). The in vitroanti cancer activity of the AuNPs was investigated using Presto Blue assay, cellular morphology, caspase 3/7 assay on the human colon cancer cell line at different times to assess the optimum time for cell death. The cellular uptake and localization of AuNPs was investigated using HRTEM to assess uptake and location of the AuNPs within the cell. Results obtained from this study showed that the AuNP synthesis from Bridellia ferrugenia was successful. The Presto Blue cell viability results showed that the AuNPs reduced cell viability (%) significantly (p<0.05) after 24 h. The optimum treatment time of HT-29 cells with AuNPs was determined to be 24 h. The apoptotic effects of the AuNPs were assessed using Cell Event reagent, and the results from this assay indicated that caspase 3/7 was activated with treatment with AuNPs which induced cell death via apoptosis. The HRTEM results indicated that there was no uptake of AuNP targeting in HT-29 therefore localization could not be determined. It can be concluded that the AuNPs synthesized from Bridellia ferrugenia have anti-cancer properties and are able to induce cell death through apoptosis. Furthermore, this study revealed that optimization of the AuNPs for cellular uptake is needed to further understand the interaction between the nanoparticles and the cells. This will provide more insight on how cellular death is induced by the nanoparticles. , Thesis (MSc) -- Faculty of Science, Department of Biochemistry and Microbiology (including Physiology), 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Zosela, Itumeleng , Davids, Hajierah
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54124 , vital:46311
- Description: Colorectal cancer (CRC) has become a health burden, being the third common cancer worldwide. Treatment of colorectal cancer is very important to manage the high prevalence rate of this disease. The available treatments for CRC have their drawbacks and side effects. Available treatments of colon cancer include surgery, chemotherapy, and radiation. Due to the side effects associated with these treatments, alternative treatments that pose less side effects are being developed worldwide. Nanotechnologies have gained global consideration due to their potential to improve the current standards and techniques for the diagnosis and treatment. The use of plants for synthesis of gold nanoparticles has opened a new venture of synthesizing environmentally friendly and cost-effective nanoparticles which possess great properties for CRC treatment. The aim of this study was to investigate the use of green synthesized AuNPs from Bridelia ferruginea for potential cancer treatment. In this work study gold nanoparticles were synthesized utilizing Bridelia ferruginea stem bark extract. The nanoparticles were characterized using UV–Vis spectroscopy, Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FTIR) and High-Resolution Transmission Electron Microscopy (HRTEM). The in vitroanti cancer activity of the AuNPs was investigated using Presto Blue assay, cellular morphology, caspase 3/7 assay on the human colon cancer cell line at different times to assess the optimum time for cell death. The cellular uptake and localization of AuNPs was investigated using HRTEM to assess uptake and location of the AuNPs within the cell. Results obtained from this study showed that the AuNP synthesis from Bridellia ferrugenia was successful. The Presto Blue cell viability results showed that the AuNPs reduced cell viability (%) significantly (p<0.05) after 24 h. The optimum treatment time of HT-29 cells with AuNPs was determined to be 24 h. The apoptotic effects of the AuNPs were assessed using Cell Event reagent, and the results from this assay indicated that caspase 3/7 was activated with treatment with AuNPs which induced cell death via apoptosis. The HRTEM results indicated that there was no uptake of AuNP targeting in HT-29 therefore localization could not be determined. It can be concluded that the AuNPs synthesized from Bridellia ferrugenia have anti-cancer properties and are able to induce cell death through apoptosis. Furthermore, this study revealed that optimization of the AuNPs for cellular uptake is needed to further understand the interaction between the nanoparticles and the cells. This will provide more insight on how cellular death is induced by the nanoparticles. , Thesis (MSc) -- Faculty of Science, Department of Biochemistry and Microbiology (including Physiology), 2021
- Full Text:
- Date Issued: 2021-12
Real-time feedback model for supporting individualised learning of programming students
- Authors: Keen, Charne
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53624 , vital:45691
- Description: Feedback is crucial to the enhancement of the learning and teaching environment, especially in those environments that suffer from a number of extrinsic challenges. The growing demands for educators to provide academic interventions throughout the lecture session and the need for continuous improvement of the quality of university education make it necessary to find and apply more effective and efficient educational technologies and practices based on the correlation of teaching with a student’s conceptual understanding and individual learning preference. Following a combination of Design Science Research (DSR) and Case Study Methodology, this research addresses this problem by designing a technology based real-time feedback (TBRTF) model that can easily be implemented in a South African University. The model designed followed a layered architecture pattern. The architecture describes the data, technology and user support layers of the model. The data support layer incorporates the collection of student academic data and learning preferences. The technology incorporates a machine learning component. The machine learning component covers two technological aspects: the prediction component and the clustering component. This TBRTF model provides the guidelines needed to develop a system that supports individualised real-time feedback in the learning and teaching environment of programming students. The aim of the model is that as the students partake in learning activities where the student data is updated, the monitoring component will fire, updating the probability of failure prediction and in turn the student clusters are regenerated. This will notify the educator of a change and provide decision making support. The student will be allocated individualised feedback in the form of learning materials based on the cluster that the student is allocated to. Through a demonstration and evaluation, this study showed that by following the proposed architecture of the TBRTF model, a model that supports individualised realtime feedback in the learning and teaching environment of programming students can be developed. The validation used an artificial neural network as the prediction component and a k-means clustering algorithm as the clustering component. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text: false
- Date Issued: 2021-12
- Authors: Keen, Charne
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53624 , vital:45691
- Description: Feedback is crucial to the enhancement of the learning and teaching environment, especially in those environments that suffer from a number of extrinsic challenges. The growing demands for educators to provide academic interventions throughout the lecture session and the need for continuous improvement of the quality of university education make it necessary to find and apply more effective and efficient educational technologies and practices based on the correlation of teaching with a student’s conceptual understanding and individual learning preference. Following a combination of Design Science Research (DSR) and Case Study Methodology, this research addresses this problem by designing a technology based real-time feedback (TBRTF) model that can easily be implemented in a South African University. The model designed followed a layered architecture pattern. The architecture describes the data, technology and user support layers of the model. The data support layer incorporates the collection of student academic data and learning preferences. The technology incorporates a machine learning component. The machine learning component covers two technological aspects: the prediction component and the clustering component. This TBRTF model provides the guidelines needed to develop a system that supports individualised real-time feedback in the learning and teaching environment of programming students. The aim of the model is that as the students partake in learning activities where the student data is updated, the monitoring component will fire, updating the probability of failure prediction and in turn the student clusters are regenerated. This will notify the educator of a change and provide decision making support. The student will be allocated individualised feedback in the form of learning materials based on the cluster that the student is allocated to. Through a demonstration and evaluation, this study showed that by following the proposed architecture of the TBRTF model, a model that supports individualised realtime feedback in the learning and teaching environment of programming students can be developed. The validation used an artificial neural network as the prediction component and a k-means clustering algorithm as the clustering component. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text: false
- Date Issued: 2021-12
The invasion autecology of Iris pseudacorus L. (Iridaceae) in South Africa
- Authors: Sandenbergh, Emma
- Date: 2022-04-06
- Subjects: Iris pseudacorus South Africa , Invasive plants South Africa , Aquatic weeds South Africa , Plant genetics South Africa , Freshwater ecology South Africa , Iris pseudacorus Geographical distribution , Phytogeography
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232272 , vital:49977
- Description: Iris pseudacorus L. (Iridaceae) is an emergent aquatic macrophyte originating from Europe, north Africa, and western Asia, and is becoming an increasingly problematic invader in South Africa. By forming dense rhizomatic mats in the absence of natural enemies, I. pseudacorus outcompetes co-occurring indigenous biota, causing serious environmental and socioeconomic challenges. Iris pseudacorus is a declared invader in South Africa, Argentina, New Zealand, the United States of America, and Canada, but little information is known regarding the species’ invasive potential, particularly in the southern hemisphere, hindering the effectiveness of control efforts. This study addresses this knowledge gap in a South African context, providing valuable insight into the invasion autecology of I. pseudacorus in South Africa. For effective management and control of I. pseudacorus in South Africa and the global south, its distribution and invasive potential must be determined, and its population genetics understood. Hence, this study aimed to map the current confirmed distribution of I. pseudacorus populations in South Africa, investigating the relative abundance of I. pseudacorus individuals in each population, and comparing their sexual reproductive outputs. Moreover, this study assessed the competitive interactions between I. pseudacorus and co-occurring native species T. capensis, and examined the genetic diversity present between and within South African I. pseudacorus populations. Through field surveys, I. pseudacorus infestations were confirmed in eight of the country’s nine provinces, with the highest number of infestations recorded in the urban hubs, and greatest population abundances reported in the warmer, wetter regions of South Africa. These surveys indicated that South African I. pseudacorus populations have enhanced their sexual reproductive output relative to native range populations, and a germination rate of ~ 83 % was determined in the laboratory. The results of a common garden competition experiment indicated that T. capensis may be a superior competitor over I. pseudacorus, but this was not supported by field observations, and may be a result of the short duration of the experiment. Using inter-simple sequence repeats (ISSRs), high genetic diversity was observed within and between populations of I. pseudacorus, indicating the employment of sexual reproductive strategies, and providing evidence for gene-flow between and within populations. Moreover, a weak negative correlation was observed between geographic distance and genetic similarity, ii indicating a largely anthropogenic spread of I. pseudacorus, and suggesting the occurrence of fewer founding events than reported in the United States. This study provides useful insight into the invasion autecology of I. pseudacorus in South Africa, contributing to the ongoing research surrounding I. pseudacorus invasions worldwide, particularly in the southern hemisphere. These results contribute to the development of appropriate adaptive and integrated management strategies to control I. pseudacorus invasions in South Africa, and should be implemented before South African I. pseudacorus infestations reach the severity observed elsewhere. , Thesis (MSc) -- Faculty of Science, Botany, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Sandenbergh, Emma
- Date: 2022-04-06
- Subjects: Iris pseudacorus South Africa , Invasive plants South Africa , Aquatic weeds South Africa , Plant genetics South Africa , Freshwater ecology South Africa , Iris pseudacorus Geographical distribution , Phytogeography
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232272 , vital:49977
- Description: Iris pseudacorus L. (Iridaceae) is an emergent aquatic macrophyte originating from Europe, north Africa, and western Asia, and is becoming an increasingly problematic invader in South Africa. By forming dense rhizomatic mats in the absence of natural enemies, I. pseudacorus outcompetes co-occurring indigenous biota, causing serious environmental and socioeconomic challenges. Iris pseudacorus is a declared invader in South Africa, Argentina, New Zealand, the United States of America, and Canada, but little information is known regarding the species’ invasive potential, particularly in the southern hemisphere, hindering the effectiveness of control efforts. This study addresses this knowledge gap in a South African context, providing valuable insight into the invasion autecology of I. pseudacorus in South Africa. For effective management and control of I. pseudacorus in South Africa and the global south, its distribution and invasive potential must be determined, and its population genetics understood. Hence, this study aimed to map the current confirmed distribution of I. pseudacorus populations in South Africa, investigating the relative abundance of I. pseudacorus individuals in each population, and comparing their sexual reproductive outputs. Moreover, this study assessed the competitive interactions between I. pseudacorus and co-occurring native species T. capensis, and examined the genetic diversity present between and within South African I. pseudacorus populations. Through field surveys, I. pseudacorus infestations were confirmed in eight of the country’s nine provinces, with the highest number of infestations recorded in the urban hubs, and greatest population abundances reported in the warmer, wetter regions of South Africa. These surveys indicated that South African I. pseudacorus populations have enhanced their sexual reproductive output relative to native range populations, and a germination rate of ~ 83 % was determined in the laboratory. The results of a common garden competition experiment indicated that T. capensis may be a superior competitor over I. pseudacorus, but this was not supported by field observations, and may be a result of the short duration of the experiment. Using inter-simple sequence repeats (ISSRs), high genetic diversity was observed within and between populations of I. pseudacorus, indicating the employment of sexual reproductive strategies, and providing evidence for gene-flow between and within populations. Moreover, a weak negative correlation was observed between geographic distance and genetic similarity, ii indicating a largely anthropogenic spread of I. pseudacorus, and suggesting the occurrence of fewer founding events than reported in the United States. This study provides useful insight into the invasion autecology of I. pseudacorus in South Africa, contributing to the ongoing research surrounding I. pseudacorus invasions worldwide, particularly in the southern hemisphere. These results contribute to the development of appropriate adaptive and integrated management strategies to control I. pseudacorus invasions in South Africa, and should be implemented before South African I. pseudacorus infestations reach the severity observed elsewhere. , Thesis (MSc) -- Faculty of Science, Botany, 2022
- Full Text:
- Date Issued: 2022-04-06
The impact of exchange rates on trade balances in SADC countries
- Authors: Nyahokwe, Olivia
- Date: 2021-12
- Subjects: Foreign exchange rates -- Africa, Southern
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54980 , vital:48575
- Description: This study aims to determine the impact of exchange rates on trade balances in SADC countries. Further, the study also aims to determine the existence of the J-curve phenomena in SADC countries. To achieve the objectives of the study, a panel GMM model and quantile regressions were used as a method of data analysis on data covering the period of 1993 to 2018. Panel GMM model and quantile regression were used to determine the relationships between the real exchange rate (XR), world income (WGDP), as well as gross domestic product (GDP), and trade balance (TB) of SADC countries. The SADC countries used in this study are South Africa, Mauritius, Lesotho, Angola, Malawi, Mozambique, DRC, Madagascar, Namibia, and Botswana. To provide a conceptual framework for the study, a comprehensive theoretical and empirical literature review was undertaken. Within the framework of the theoretical literature review, Magee’s (1973) J-curve phenomena were tested for its relevance and application within SADC countries. Given the main highlights of the empirical literature review, this J-curve phenomenon as well as the impact of trade balances in SADC countries, has not been addressed optimally. The main focus of previous studies in this area within SADC countries has fallen short of explaining the nature and causality of J-curve phenomena. It is in this respect that this study contributes to the regional and international trade discourse. The main findings from the quantile regression analysis in this study suggest that no evidence of "J-curve" in the case of Angola, Namibia, Mozambique, Malawi, and Madagascar. South Africa shows a delayed J curve. Lesotho an inverted J-curve, whilst DRC and Botswana show a sharp V-shape. Contrary to the "J-curve" phenomenon, as explained by the classical textbooks, the findings of the study suggest that the depreciation of Namibia, Mozambique, Angola, Malawi, and Madagascar’s exchange rates produce no J-curve phenomenon, indicating that there is no room for improving these countries’ trade balances through a currency devaluation process. Yet for countries such as South Africa, DRC, Botswana, and Mauritius the findings suggest that the depreciation of these countries’ exchange rates improves the trade balances. Concerning GMM results, the exchange rate and gross domestic product in SADC countries had a positive relationship with the trade balances in SADC countries. Further, the exchange rates also show evidence of a positive relationship with trade balances. On the contrary, the world income (represented as world GDP) has a negative relationship with trade balances in SADC countries. This implies that, as SADC currencies strengthen, the trade balance worsens. This finding presents a serious open macroeconomic challenge in SADC countries, in that the trade balances worsen irrespective of the strengths of the currencies; hence the trade balances in SADC countries have remained negative for prolonged periods. Furthermore, the world economic growth does not necessarily improve the SADC countries' trade balances either, as shown by a negative relation between world income and trade balances in SADC countries. This finding concerning world GDP, suggests that SADC countries lack export diversification and are trapped in primary product exports which, at times, are subjected to low prices. Given the above findings, it is clear that SADC countries will continue to suffer from negative trade balances, which in turn will continue to stifle their growth. To address the continued and persistent trade balances in SADC countries, policymakers should focus on an integrated open macroeconomic strategy. Such a strategy should pay special attention to improving technical skills, research, and development, quality of exports, export diversification, infrastructure; maintain the use of flexible exchange rate regimes, raise the level of productivity; substitute imports of capital equipment and support domestic industries. Furthermore, it is recommended that SADC countries focus on attracting and retaining foreign direct investments. This macroeconomic strategy should not be approached in isolation but as an integrated policy framework. , Thesis (PhD) -- Faculty of Business and Economic Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Nyahokwe, Olivia
- Date: 2021-12
- Subjects: Foreign exchange rates -- Africa, Southern
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54980 , vital:48575
- Description: This study aims to determine the impact of exchange rates on trade balances in SADC countries. Further, the study also aims to determine the existence of the J-curve phenomena in SADC countries. To achieve the objectives of the study, a panel GMM model and quantile regressions were used as a method of data analysis on data covering the period of 1993 to 2018. Panel GMM model and quantile regression were used to determine the relationships between the real exchange rate (XR), world income (WGDP), as well as gross domestic product (GDP), and trade balance (TB) of SADC countries. The SADC countries used in this study are South Africa, Mauritius, Lesotho, Angola, Malawi, Mozambique, DRC, Madagascar, Namibia, and Botswana. To provide a conceptual framework for the study, a comprehensive theoretical and empirical literature review was undertaken. Within the framework of the theoretical literature review, Magee’s (1973) J-curve phenomena were tested for its relevance and application within SADC countries. Given the main highlights of the empirical literature review, this J-curve phenomenon as well as the impact of trade balances in SADC countries, has not been addressed optimally. The main focus of previous studies in this area within SADC countries has fallen short of explaining the nature and causality of J-curve phenomena. It is in this respect that this study contributes to the regional and international trade discourse. The main findings from the quantile regression analysis in this study suggest that no evidence of "J-curve" in the case of Angola, Namibia, Mozambique, Malawi, and Madagascar. South Africa shows a delayed J curve. Lesotho an inverted J-curve, whilst DRC and Botswana show a sharp V-shape. Contrary to the "J-curve" phenomenon, as explained by the classical textbooks, the findings of the study suggest that the depreciation of Namibia, Mozambique, Angola, Malawi, and Madagascar’s exchange rates produce no J-curve phenomenon, indicating that there is no room for improving these countries’ trade balances through a currency devaluation process. Yet for countries such as South Africa, DRC, Botswana, and Mauritius the findings suggest that the depreciation of these countries’ exchange rates improves the trade balances. Concerning GMM results, the exchange rate and gross domestic product in SADC countries had a positive relationship with the trade balances in SADC countries. Further, the exchange rates also show evidence of a positive relationship with trade balances. On the contrary, the world income (represented as world GDP) has a negative relationship with trade balances in SADC countries. This implies that, as SADC currencies strengthen, the trade balance worsens. This finding presents a serious open macroeconomic challenge in SADC countries, in that the trade balances worsen irrespective of the strengths of the currencies; hence the trade balances in SADC countries have remained negative for prolonged periods. Furthermore, the world economic growth does not necessarily improve the SADC countries' trade balances either, as shown by a negative relation between world income and trade balances in SADC countries. This finding concerning world GDP, suggests that SADC countries lack export diversification and are trapped in primary product exports which, at times, are subjected to low prices. Given the above findings, it is clear that SADC countries will continue to suffer from negative trade balances, which in turn will continue to stifle their growth. To address the continued and persistent trade balances in SADC countries, policymakers should focus on an integrated open macroeconomic strategy. Such a strategy should pay special attention to improving technical skills, research, and development, quality of exports, export diversification, infrastructure; maintain the use of flexible exchange rate regimes, raise the level of productivity; substitute imports of capital equipment and support domestic industries. Furthermore, it is recommended that SADC countries focus on attracting and retaining foreign direct investments. This macroeconomic strategy should not be approached in isolation but as an integrated policy framework. , Thesis (PhD) -- Faculty of Business and Economic Sciences, 2021
- Full Text:
- Date Issued: 2021-12
A critical exploration of the attitudes towards and knowledge of natural resource management amongst first-year Natural Resource Management students
- Authors: Jooste, Eileen
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's , text
- Identifier: http://hdl.handle.net/10948/53666 , vital:45688
- Description: Available literature suggests that there is a need to gain more understanding of what students’ environmental attitudes and knowledge are and how they are developed by education systems. Education, in general, plays an important role in students’ attitudes and their knowledge of the world around them. It can shape students’ awareness of their natural environment and contribute to their understanding of environmental issues. Education can also strengthen students’ critical thinking, build awareness, stimulate problem solving, and promote sustainable practices. It has the potential to empower students to address global challenges from their own diverse perspectives and prepare them to uphold the economy. Education can improve and maintain societal wellbeing and can help students to maintain the natural environment, along with achieving sustainable development. Environmental education, specifically, can play a big role in how students deal with the natural environment. The primary aim of this qualitative research study was to examine first-year students’ environmental attitudes and knowledge in the School of Natural Resource Management at the Nelson Mandela University George Campus, South Africa. First-year students’ environmental attitudes and knowledge were examined as they entered the university, and then again at the end of the first semester once they had completed a module in ecology. More specifically, at the outset of the research the objectives were (1) to establish an understanding of the baseline environmental attitudes and knowledge of first-year students who were undertaking three ecological modules being offered by the School of Natural Resource Management; (2) to assess the changes in the first-year students’ environmental attitudes and knowledge, using a post-intervention strategy; (3) to understand what type of teaching approaches were used by the lecturers teaching the ecological modules; and (4) to evaluate how the teaching approaches of the lecturers influenced the baseline environmental attitudes and knowledge of the student group. This research took place in the midst of the Corona Virus pandemic, which had significantly influenced the teaching and learning environment. Multiple education systems, including those of the Nelson Mandela University George Campus, had to rapidly transition to online teaching and learning. So, although unplanned for, this research could not ignore the rapid transition to online teaching and learning and the role it played in shaping the first-year School of Natural Resource Management students’ environmental attitudes and knowledge. It also impacted the teaching approaches of the environmental lecturers. An additional objective in response to the rapid transition to online teaching and learning was, therefore, added: (5) to understand the experiences of the first-year School of Natural Resource Management students and the three environmental lecturers who had to rapidly transition to online teaching and learning. Data was collected via questionnaires and semi-structured interviews with students and staff in the School of Natural Resource Management at Nelson Mandela University George Campus within three different natural resource management programs, namely Agriculture, Nature Conservation, and Forestry. Baseline questionnaires were conducted with 107 students for a baseline assessment as the students entered the university. An online post-intervention questionnaire was conducted with 33 of the initial group of students at the end of the semester for a post-intervention assessment. In-depth semi-structured interviews were conducted with three environmental lectures before they taught their three ecology modules in each of the programs. Additional online semi-structured interviews were also done with the same three environmental lectures after the rapid transition to online teaching and learning took place. The significant findings from this research were analyzed and discussed. This included the baseline environmental attitudes and knowledge of the student body upon arrival at the university and the changes in their environmental attitudes and knowledge after they were exposed to the ecology modules taught in each of the programs. The discussion also included the teaching approaches adopted by the environmental lecturers and the influence their teaching approaches had on the students’ environmental attitudes and knowledge. In addition, the results shed light on the experiences of students and lecturers during the rapid transition to online teaching and learning. The main conclusions reached were that the first-year School of Natural Resource Management students did not have a deep understanding of ecological concepts prior to arriving at university, but they did show a concern for the natural environment. Their lack of understanding was reduced as the students progressed with the ecology module. A greater understanding resulted in a change in students’ perspectives on the ecological module, their program, and the industry they were preparing to enter after being exposed to the ecology module. The environmental lecturers’ teaching approaches contributed to improving the students’ environmental attitudes and knowledge. When it came to the rapid transition to online teaching and learning, both the first-year School of Natural Resource Management students and environmental lecturers experienced benefits and challenges. , Thesis (MSc) -- Faculty of Science, School of Natural Resource Management, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Jooste, Eileen
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's , text
- Identifier: http://hdl.handle.net/10948/53666 , vital:45688
- Description: Available literature suggests that there is a need to gain more understanding of what students’ environmental attitudes and knowledge are and how they are developed by education systems. Education, in general, plays an important role in students’ attitudes and their knowledge of the world around them. It can shape students’ awareness of their natural environment and contribute to their understanding of environmental issues. Education can also strengthen students’ critical thinking, build awareness, stimulate problem solving, and promote sustainable practices. It has the potential to empower students to address global challenges from their own diverse perspectives and prepare them to uphold the economy. Education can improve and maintain societal wellbeing and can help students to maintain the natural environment, along with achieving sustainable development. Environmental education, specifically, can play a big role in how students deal with the natural environment. The primary aim of this qualitative research study was to examine first-year students’ environmental attitudes and knowledge in the School of Natural Resource Management at the Nelson Mandela University George Campus, South Africa. First-year students’ environmental attitudes and knowledge were examined as they entered the university, and then again at the end of the first semester once they had completed a module in ecology. More specifically, at the outset of the research the objectives were (1) to establish an understanding of the baseline environmental attitudes and knowledge of first-year students who were undertaking three ecological modules being offered by the School of Natural Resource Management; (2) to assess the changes in the first-year students’ environmental attitudes and knowledge, using a post-intervention strategy; (3) to understand what type of teaching approaches were used by the lecturers teaching the ecological modules; and (4) to evaluate how the teaching approaches of the lecturers influenced the baseline environmental attitudes and knowledge of the student group. This research took place in the midst of the Corona Virus pandemic, which had significantly influenced the teaching and learning environment. Multiple education systems, including those of the Nelson Mandela University George Campus, had to rapidly transition to online teaching and learning. So, although unplanned for, this research could not ignore the rapid transition to online teaching and learning and the role it played in shaping the first-year School of Natural Resource Management students’ environmental attitudes and knowledge. It also impacted the teaching approaches of the environmental lecturers. An additional objective in response to the rapid transition to online teaching and learning was, therefore, added: (5) to understand the experiences of the first-year School of Natural Resource Management students and the three environmental lecturers who had to rapidly transition to online teaching and learning. Data was collected via questionnaires and semi-structured interviews with students and staff in the School of Natural Resource Management at Nelson Mandela University George Campus within three different natural resource management programs, namely Agriculture, Nature Conservation, and Forestry. Baseline questionnaires were conducted with 107 students for a baseline assessment as the students entered the university. An online post-intervention questionnaire was conducted with 33 of the initial group of students at the end of the semester for a post-intervention assessment. In-depth semi-structured interviews were conducted with three environmental lectures before they taught their three ecology modules in each of the programs. Additional online semi-structured interviews were also done with the same three environmental lectures after the rapid transition to online teaching and learning took place. The significant findings from this research were analyzed and discussed. This included the baseline environmental attitudes and knowledge of the student body upon arrival at the university and the changes in their environmental attitudes and knowledge after they were exposed to the ecology modules taught in each of the programs. The discussion also included the teaching approaches adopted by the environmental lecturers and the influence their teaching approaches had on the students’ environmental attitudes and knowledge. In addition, the results shed light on the experiences of students and lecturers during the rapid transition to online teaching and learning. The main conclusions reached were that the first-year School of Natural Resource Management students did not have a deep understanding of ecological concepts prior to arriving at university, but they did show a concern for the natural environment. Their lack of understanding was reduced as the students progressed with the ecology module. A greater understanding resulted in a change in students’ perspectives on the ecological module, their program, and the industry they were preparing to enter after being exposed to the ecology module. The environmental lecturers’ teaching approaches contributed to improving the students’ environmental attitudes and knowledge. When it came to the rapid transition to online teaching and learning, both the first-year School of Natural Resource Management students and environmental lecturers experienced benefits and challenges. , Thesis (MSc) -- Faculty of Science, School of Natural Resource Management, 2021
- Full Text:
- Date Issued: 2021-12
Mapping the importance of public participation in the expropriation of land without compensation bill: a case of Silver Town in KwaZakhele, Port Elizabeth
- Authors: Ngwabeni, Siyasanga
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54541 , vital:46686
- Description: The post-1994 era in the South African public imagination was envisaged to herald widespread and transformative efforts to reverse the gross injustices and human rights violations inflicted over many decades of apartheid and colonialism. One of the key measures initiated by the democratic government to drive this nation building project was the land reform programme. The ‘land question’, which is a popular tagline in South Africa when reference is made to land reform, has come to define the general discourse of socioeconomic disadvantage and change in the post-apartheid and post-colonial period – similarly to other former settler colonies in the African continent and the broader Global South. For South Africa though, this specific issue has been characterised by numerous challenges and failures largely at the level of the state, wherein a significant lack of public engagement, public participation and democratic redistribution was not being done according to ‘the will of the people’. On a number of occasions, the South African state has gone on a ‘solo crusade’ to implement the land reform programme under complex conditions that are largely unfavoured by ordinary people ‘on the ground’ – especially those who were the primary victims of land dispossession under colonialism and apartheid. As a result, over the past few years, indigenous black communities across the country especially in (semi)urban and township areas have voluntarily ‘occupied’ land at their own will and sometimes ‘illegally’, as a way to take up settlement space and determine their lives on the land of their birth. Beyond the public discourse of ‘land invasions’ and ‘failed land reform projects’, this study was conducted to closely understand the extent to which public engagement and participation has been integral in the systematic mechanism(s) to transform the patterns of land ownership and control in the democratic South Africa. To do this, the site of KwaZakhele, Silvertown, in Port Elizabeth was selected to conduct the study. This township is an outcome of apartheid geography and land dispossession where many generations of indigenous black people were displaced. Today, it is a struggling community characterised by high rates of poverty and unemployment – and one of its unresolved socio-political issues is the question of the skewed patterns of land ownership in the area. Methodologically, qualitative semi-structured interviews were utilised to conduct the study and the Marxist Concept of Citizenship was selected as a theoretical framework for the study by the researcher. The study has found that, amongst the general legislative and political shortfalls of public participation breakdown, there are other deep seated structural socioeconomic issues that are at the root of the problem – such as economic inequalities and very low prospects of social mobility – which collectively reproduce the persistent inadequacies of political instability and social unrest in the area. The study recommends an astute combination of ‘bottom-up’ active citizenship and major socioeconomic transformation in the area as a systematic and structural mechanism to empower the community of Silvertown to be the champion of its own liberation struggle for the freedom of its people to own land and democratically participate in their own governance, self-determination, and prosperity. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Ngwabeni, Siyasanga
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54541 , vital:46686
- Description: The post-1994 era in the South African public imagination was envisaged to herald widespread and transformative efforts to reverse the gross injustices and human rights violations inflicted over many decades of apartheid and colonialism. One of the key measures initiated by the democratic government to drive this nation building project was the land reform programme. The ‘land question’, which is a popular tagline in South Africa when reference is made to land reform, has come to define the general discourse of socioeconomic disadvantage and change in the post-apartheid and post-colonial period – similarly to other former settler colonies in the African continent and the broader Global South. For South Africa though, this specific issue has been characterised by numerous challenges and failures largely at the level of the state, wherein a significant lack of public engagement, public participation and democratic redistribution was not being done according to ‘the will of the people’. On a number of occasions, the South African state has gone on a ‘solo crusade’ to implement the land reform programme under complex conditions that are largely unfavoured by ordinary people ‘on the ground’ – especially those who were the primary victims of land dispossession under colonialism and apartheid. As a result, over the past few years, indigenous black communities across the country especially in (semi)urban and township areas have voluntarily ‘occupied’ land at their own will and sometimes ‘illegally’, as a way to take up settlement space and determine their lives on the land of their birth. Beyond the public discourse of ‘land invasions’ and ‘failed land reform projects’, this study was conducted to closely understand the extent to which public engagement and participation has been integral in the systematic mechanism(s) to transform the patterns of land ownership and control in the democratic South Africa. To do this, the site of KwaZakhele, Silvertown, in Port Elizabeth was selected to conduct the study. This township is an outcome of apartheid geography and land dispossession where many generations of indigenous black people were displaced. Today, it is a struggling community characterised by high rates of poverty and unemployment – and one of its unresolved socio-political issues is the question of the skewed patterns of land ownership in the area. Methodologically, qualitative semi-structured interviews were utilised to conduct the study and the Marxist Concept of Citizenship was selected as a theoretical framework for the study by the researcher. The study has found that, amongst the general legislative and political shortfalls of public participation breakdown, there are other deep seated structural socioeconomic issues that are at the root of the problem – such as economic inequalities and very low prospects of social mobility – which collectively reproduce the persistent inadequacies of political instability and social unrest in the area. The study recommends an astute combination of ‘bottom-up’ active citizenship and major socioeconomic transformation in the area as a systematic and structural mechanism to empower the community of Silvertown to be the champion of its own liberation struggle for the freedom of its people to own land and democratically participate in their own governance, self-determination, and prosperity. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text:
- Date Issued: 2021-12
Ocean structures and dynamics of two open bays on the eastern Agulhas Bank
- Authors: Dlomo, Xolisa
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53607 , vital:45680
- Description: Upwelling, bay-scale currents, fronts and mixing in Algoa Bay and St Francis Bay occur over both short and long time periods. These physical ocean dynamics drive the temporal and spatial distribution of nutrients in the bays, there by influencing primary and secondary production. Thermal gradients and fronts are driven by the wind and open ocean influences, such as the Agulhas Current, daily and seasonal variations in solar radiation, long and short period waves, air-sea fluxes, coastal trapped waves and terrestrial freshwater inflow. These phenomena are poorly understood along this part of the coastline and were the focus of this study. I investigated the dominant temperature scales of variability in both bays, to determine which isotherm is best suited to describe temperature fluctuations and thermocline spatiotemporal variability in and between the two bays. I investigated upwelling spatiotemporal variability in the two bays and tested whether upwelling occurs at the opposite sides of the bays with a change in wind direction. Thereafter studied the occurrence and drivers of winter upwelling events. The wind-driven current spatiotemporal variability and correlations were investigated at the extremities of the two bays. The daily, intra-seasonal and yearly variation in temperature structures in Algoa Bay and St. Francis Bay were mainly driven by the local winds, coastal topography, and bathymetry. The most suitable isotherm to describe thermal fluctuations and variability in Algoa Bay shallower sites was 16.5 °C and its mean depth was 16.2 m. The best isotherm for the deeper sites in Algoa Bay was 15.7 °C with a depth of 33.1 m. The average temperature and depth of the best isotherm to describe thermal fluctuations in St. Francis Bay for the shallower sites was15.80 °C and 16.83 m, and for the deeper sites it was 15.10 °C and 32.08 m. Algoa Bay showed an average cooling trend of -0.000172 °C per year, whereas in St. Francis Bay a warming average trend of 0.0188 °C per year was observed over the study period often and six years, respectively. The wind, Coriolis Effect and Ekman Transport were the main external forces that influenced upwelling throughout the year. Since the available mesoscale indices for upwelling intensity lack the resolution needed to characterize and compare inner-shelf upwelling regimes at small spatial scales, I developed a new local, quantitative index of thermal variability. Index calculations were based on hourly records of in site depth-averaged temperatures, measured at 6 sites in St. Francis Bay and at 8 sites in Algoa Bay. Using the Multivariate Upwelling Zone Index of Cooling (MUZIC) I found that Woody Cape and Blue Horizon Bay had the highest upwelling intensity in Algoa Bay and St. Francis Bay, respectively. The other sites were ordinated and ranked according to their upwelling rates and intensity. Evidence of wind-driven winter upwelling was found to be a common occurrence in both bays. There was no obvious current seasonality observed, however, strong spectral signals in the period of a weather band (4 –7 days) were present. Current structures were generally positively correlated with wind variations in both bays. Thus, when westerly/easterly winds blew the overall surface current direction was eastward/westward. I observed a pronounced current spatiotemporal variability that was driven by local winds. The Bird Island surface currents in Algoa Bay were strongly correlated at 0–lag day with the winds, however, in Cape Recife the strongest correlations were usually observed at 1–lag day highlighting the spatiotemporal influence of wind regimes on current structures in Algoa Bay. Bird Island current speeds were higher and had an obvious bimodal directional variation (south westward /north eastward) compared to Cape Recife currents, which generally had a slower current speed with a strong west-north westward direction. In St. Francis Bay, the Schoenmakerskop surface currents showed weak positive correlation with winds at 0–lag day, however, stronger negative correlations were observed at 4–lag days. The current surface speeds in Schoenmakerskop were the lowest and varied directionally between north-north eastward and south-south eastward. The basic data requirements (i.e. SST/ UTR and ADCP time series) and the simplicity of the calculations make these indices a useful tool to apply to a large number of sites nationally and internationally, and to examine the generality of community and population-level responses to physical forcing. , Thesis (PhD) -- Faculty of Science, Journalsim and Media Studies, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Dlomo, Xolisa
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53607 , vital:45680
- Description: Upwelling, bay-scale currents, fronts and mixing in Algoa Bay and St Francis Bay occur over both short and long time periods. These physical ocean dynamics drive the temporal and spatial distribution of nutrients in the bays, there by influencing primary and secondary production. Thermal gradients and fronts are driven by the wind and open ocean influences, such as the Agulhas Current, daily and seasonal variations in solar radiation, long and short period waves, air-sea fluxes, coastal trapped waves and terrestrial freshwater inflow. These phenomena are poorly understood along this part of the coastline and were the focus of this study. I investigated the dominant temperature scales of variability in both bays, to determine which isotherm is best suited to describe temperature fluctuations and thermocline spatiotemporal variability in and between the two bays. I investigated upwelling spatiotemporal variability in the two bays and tested whether upwelling occurs at the opposite sides of the bays with a change in wind direction. Thereafter studied the occurrence and drivers of winter upwelling events. The wind-driven current spatiotemporal variability and correlations were investigated at the extremities of the two bays. The daily, intra-seasonal and yearly variation in temperature structures in Algoa Bay and St. Francis Bay were mainly driven by the local winds, coastal topography, and bathymetry. The most suitable isotherm to describe thermal fluctuations and variability in Algoa Bay shallower sites was 16.5 °C and its mean depth was 16.2 m. The best isotherm for the deeper sites in Algoa Bay was 15.7 °C with a depth of 33.1 m. The average temperature and depth of the best isotherm to describe thermal fluctuations in St. Francis Bay for the shallower sites was15.80 °C and 16.83 m, and for the deeper sites it was 15.10 °C and 32.08 m. Algoa Bay showed an average cooling trend of -0.000172 °C per year, whereas in St. Francis Bay a warming average trend of 0.0188 °C per year was observed over the study period often and six years, respectively. The wind, Coriolis Effect and Ekman Transport were the main external forces that influenced upwelling throughout the year. Since the available mesoscale indices for upwelling intensity lack the resolution needed to characterize and compare inner-shelf upwelling regimes at small spatial scales, I developed a new local, quantitative index of thermal variability. Index calculations were based on hourly records of in site depth-averaged temperatures, measured at 6 sites in St. Francis Bay and at 8 sites in Algoa Bay. Using the Multivariate Upwelling Zone Index of Cooling (MUZIC) I found that Woody Cape and Blue Horizon Bay had the highest upwelling intensity in Algoa Bay and St. Francis Bay, respectively. The other sites were ordinated and ranked according to their upwelling rates and intensity. Evidence of wind-driven winter upwelling was found to be a common occurrence in both bays. There was no obvious current seasonality observed, however, strong spectral signals in the period of a weather band (4 –7 days) were present. Current structures were generally positively correlated with wind variations in both bays. Thus, when westerly/easterly winds blew the overall surface current direction was eastward/westward. I observed a pronounced current spatiotemporal variability that was driven by local winds. The Bird Island surface currents in Algoa Bay were strongly correlated at 0–lag day with the winds, however, in Cape Recife the strongest correlations were usually observed at 1–lag day highlighting the spatiotemporal influence of wind regimes on current structures in Algoa Bay. Bird Island current speeds were higher and had an obvious bimodal directional variation (south westward /north eastward) compared to Cape Recife currents, which generally had a slower current speed with a strong west-north westward direction. In St. Francis Bay, the Schoenmakerskop surface currents showed weak positive correlation with winds at 0–lag day, however, stronger negative correlations were observed at 4–lag days. The current surface speeds in Schoenmakerskop were the lowest and varied directionally between north-north eastward and south-south eastward. The basic data requirements (i.e. SST/ UTR and ADCP time series) and the simplicity of the calculations make these indices a useful tool to apply to a large number of sites nationally and internationally, and to examine the generality of community and population-level responses to physical forcing. , Thesis (PhD) -- Faculty of Science, Journalsim and Media Studies, 2021
- Full Text:
- Date Issued: 2021-12
Mangrove response to water level changes at the Nxaxo-Ngqusi and St Lucia Estuaries
- Authors: Julie, Corianna Lauren
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53644 , vital:45689
- Description: Water level variability within an estuary can vary as a function of tides (inundation frequency and duration) and rainfall, acting as one of the main determinants of mangrove growth, diversity, productivity, and distribution. Understanding how mangroves respond in estuaries to water level variability provides baseline information which can be used to predict future changes in mangrove growth and distribution in response to this driver This study measured mangrove characteristics (growth, structure, and areal extent) in two estuaries that differed in tidal setting, and thus water variability; the Nxaxo-Ngqusi and St Lucia estuaries, South Africa. These estuaries are part of a long-term monitoring programme (2010 - 2020) that has recorded mangrove responses to environmental changes. At the Nxaxo-Ngqusi Estuary, long-tem sea-level data (2003 – 2018) collected from the nearest tide gauge, and mangrove growth and areal extent were used to assess mangrove characteristics in a permanently open, micro tidal setting.Additionally, short-term water level data (August 2019 – September 2020), measured with in situ loggers, and sediment input at different sites within the mangrove forest, were also measured. Data was collected along the main channel sites, and at previously set up cattle exclusion plots ( browsed and non-browsed sites set to establish the effect of cattle browsing on mangroves). Similarly, at the St Lucia Estuary, long term water level data (2004 – 2020) collected at the bridge in the lower reaches of the estuary by Ezemvelo KZN-Wildlife, and annual mangrove growth, structure and areal extent data were used to assess mangrove characteristics in an estuarine lake that undergoes cycles between hypersaline and freshwater-dominated states. The results showed that mangrove responses to water level changes are complex and depend on several factors such as estuary mouth dynamics, anthropogenic activities, and site-level environmental conditions. The first objective was to compare water level changes and mangrove structure (mangrove height, and pneumatophore characteristics such as height, density and % aerenchyma) and sediment input between different sites at each estuary. Mangrove growth was higher at sites where longer inundation and higher inundation frequency were recorded at the Nxaxo-Ngqusi Estuary. However,longer inundation periods under closed mouth conditions resulted in stunted growth and mangrove dieback at St Lucia Estuary. At the Nxaxo-Ngqusi Estuary, mangroves at the main channel sites, closer to the water’s edge, had an overall higher growth rate (2.8 – 45.9 cm yr-1) than the mangroves found at the browsed (0 – 25 cm yr-1) and non-browsed sites (0 – 25.3 cm yr-1) on the landward edge of the forest. The effect of cattle browsing at these sites forms part of a long-term monitoring programme and this disturbance could have also influenced the results. Mangrove growth rate was higher in years with more rainfall at all sites within the estuary. At the St Lucia Estuary, mangrove growth rate was highest (0.81 cm yr-1) at a lower mean water level range (0.13 – 1.72 m) between 2010 - 2015, and growth rate was lowest (1.3 cm yr-1) in higher mean water level range conditions (0.34 m – 2.18 m) between 2015 – 2020. When water levels increased by up to 1.1 m due to closed mouth conditions, this led to extensive mangrove dieback further upstream by 2015. The maximum tidal flooding depth and inundation period influenced pneumatophore structure (height, density, and % aerenchyma) at the Nxaxo-Ngqusi Estuary. Sediment accumulation was highest at sites with increased pneumatophore density, but accumulation rates at the Nxaxo-Ngqusi Estuary (0.4 – 0.7 g over a high tide lasting 4-5 hours) were low and did not lead to smothering of the pneumatophores. Total sediment accumulation was highest at sites that experienced greater flooding depths. Increased inundation at the St Lucia Estuary caused inundation stress which led to mangrove mortality. This is because these mangroves are found in a closed estuary where increased water levels lead to prolonged submergence of the pneumatophores. A decrease in mangrove area was recorded at both sites. Low rainfall coupled with cattle browsing caused a decrease in mangrove area of 22% between 2009 and 2019, particularly along the mangrove fringe area at the Nxaxo-Ngqusi Estuary. The mangroves at the St Lucia Estuary, however, experienced mangrove dieback at all sites, with Site 1 recording the greatest percentage decrease in area of 71.7 % (loss of 44.76 ha) between 2010 and 2020. This was related to the progressive increase of freshwater input and water level at St Lucia Estuary under closed mouth conditions. The years leading up to 2019 had peaks in water levels at the St Lucia Estuary, with the highest water level of 2.12 m in 2019 since 2002. As a consequence, there was increased reed growth, where reeds expanded by 58% (177 ha) due to the high influx of freshwater, and no tidal exchange, which occurred in conjunction with a loss of 60.% (42 ha) of the original mangrove extent at the St Lucia Estuary. This study shows that increased water level changes (inundation frequency and duration) at the Nxaxo-Ngqusi Estuary maintain healthy mangrove stands. This is in contrast to the St Lucia Estuary, where there was a loss of mangroves as a result of high water levels under closed mouth conditions. Mangrove growth and extent at the Nxaxo-Ngqusi Estuary fluctuated in response to drought, and trampling and browsing by livestock. Extensive inundation and lack of tidal exchange reduced mangrove growth and extent at the St Lucia Estuary, with mangrove dieback occurring at all sites. These two systems are representative of the dynamic conditions found in South African estuaries. These research findings suggest that the continuous effects of climate change on estuarine habitats could result in changes in estuary mouth dynamics, which could impact mangrove growth, structure, and extent. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text: false
- Date Issued: 2021-12
- Authors: Julie, Corianna Lauren
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53644 , vital:45689
- Description: Water level variability within an estuary can vary as a function of tides (inundation frequency and duration) and rainfall, acting as one of the main determinants of mangrove growth, diversity, productivity, and distribution. Understanding how mangroves respond in estuaries to water level variability provides baseline information which can be used to predict future changes in mangrove growth and distribution in response to this driver This study measured mangrove characteristics (growth, structure, and areal extent) in two estuaries that differed in tidal setting, and thus water variability; the Nxaxo-Ngqusi and St Lucia estuaries, South Africa. These estuaries are part of a long-term monitoring programme (2010 - 2020) that has recorded mangrove responses to environmental changes. At the Nxaxo-Ngqusi Estuary, long-tem sea-level data (2003 – 2018) collected from the nearest tide gauge, and mangrove growth and areal extent were used to assess mangrove characteristics in a permanently open, micro tidal setting.Additionally, short-term water level data (August 2019 – September 2020), measured with in situ loggers, and sediment input at different sites within the mangrove forest, were also measured. Data was collected along the main channel sites, and at previously set up cattle exclusion plots ( browsed and non-browsed sites set to establish the effect of cattle browsing on mangroves). Similarly, at the St Lucia Estuary, long term water level data (2004 – 2020) collected at the bridge in the lower reaches of the estuary by Ezemvelo KZN-Wildlife, and annual mangrove growth, structure and areal extent data were used to assess mangrove characteristics in an estuarine lake that undergoes cycles between hypersaline and freshwater-dominated states. The results showed that mangrove responses to water level changes are complex and depend on several factors such as estuary mouth dynamics, anthropogenic activities, and site-level environmental conditions. The first objective was to compare water level changes and mangrove structure (mangrove height, and pneumatophore characteristics such as height, density and % aerenchyma) and sediment input between different sites at each estuary. Mangrove growth was higher at sites where longer inundation and higher inundation frequency were recorded at the Nxaxo-Ngqusi Estuary. However,longer inundation periods under closed mouth conditions resulted in stunted growth and mangrove dieback at St Lucia Estuary. At the Nxaxo-Ngqusi Estuary, mangroves at the main channel sites, closer to the water’s edge, had an overall higher growth rate (2.8 – 45.9 cm yr-1) than the mangroves found at the browsed (0 – 25 cm yr-1) and non-browsed sites (0 – 25.3 cm yr-1) on the landward edge of the forest. The effect of cattle browsing at these sites forms part of a long-term monitoring programme and this disturbance could have also influenced the results. Mangrove growth rate was higher in years with more rainfall at all sites within the estuary. At the St Lucia Estuary, mangrove growth rate was highest (0.81 cm yr-1) at a lower mean water level range (0.13 – 1.72 m) between 2010 - 2015, and growth rate was lowest (1.3 cm yr-1) in higher mean water level range conditions (0.34 m – 2.18 m) between 2015 – 2020. When water levels increased by up to 1.1 m due to closed mouth conditions, this led to extensive mangrove dieback further upstream by 2015. The maximum tidal flooding depth and inundation period influenced pneumatophore structure (height, density, and % aerenchyma) at the Nxaxo-Ngqusi Estuary. Sediment accumulation was highest at sites with increased pneumatophore density, but accumulation rates at the Nxaxo-Ngqusi Estuary (0.4 – 0.7 g over a high tide lasting 4-5 hours) were low and did not lead to smothering of the pneumatophores. Total sediment accumulation was highest at sites that experienced greater flooding depths. Increased inundation at the St Lucia Estuary caused inundation stress which led to mangrove mortality. This is because these mangroves are found in a closed estuary where increased water levels lead to prolonged submergence of the pneumatophores. A decrease in mangrove area was recorded at both sites. Low rainfall coupled with cattle browsing caused a decrease in mangrove area of 22% between 2009 and 2019, particularly along the mangrove fringe area at the Nxaxo-Ngqusi Estuary. The mangroves at the St Lucia Estuary, however, experienced mangrove dieback at all sites, with Site 1 recording the greatest percentage decrease in area of 71.7 % (loss of 44.76 ha) between 2010 and 2020. This was related to the progressive increase of freshwater input and water level at St Lucia Estuary under closed mouth conditions. The years leading up to 2019 had peaks in water levels at the St Lucia Estuary, with the highest water level of 2.12 m in 2019 since 2002. As a consequence, there was increased reed growth, where reeds expanded by 58% (177 ha) due to the high influx of freshwater, and no tidal exchange, which occurred in conjunction with a loss of 60.% (42 ha) of the original mangrove extent at the St Lucia Estuary. This study shows that increased water level changes (inundation frequency and duration) at the Nxaxo-Ngqusi Estuary maintain healthy mangrove stands. This is in contrast to the St Lucia Estuary, where there was a loss of mangroves as a result of high water levels under closed mouth conditions. Mangrove growth and extent at the Nxaxo-Ngqusi Estuary fluctuated in response to drought, and trampling and browsing by livestock. Extensive inundation and lack of tidal exchange reduced mangrove growth and extent at the St Lucia Estuary, with mangrove dieback occurring at all sites. These two systems are representative of the dynamic conditions found in South African estuaries. These research findings suggest that the continuous effects of climate change on estuarine habitats could result in changes in estuary mouth dynamics, which could impact mangrove growth, structure, and extent. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text: false
- Date Issued: 2021-12
Coordination polymers for denitrogenation of fuel oils
- Authors: Dembaremba, Tendai O
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53630 , vital:45682
- Description: In this thesis, we present adsorptive removal of nitrogen-containing compounds from fuel oil as an alternative to complement conventional hydrotreatment to obtain ultra-low sulfur and nitrogen levels. This is in cognizance of the challenges nitrogen-containing compounds pose to the hydrotreatment process, particularly their inhibition and/or poisoning of the catalysts used in the process, of which basic nitrogen-containing compounds are the major culprits. Selectivity is the biggest challenge for adsorptive removal of nitrogen-containing compounds. We explore reticular synthesis of metal organic frameworks and the use of coordinatively unsaturated metal sites in 1-dimensional coordination polymers to achieve good selectivity for nitrogen-containing compounds. In the first part of the thesis, reticular synthesis of metal organic frameworks to control the size of the cavity, and strategically use the linkers and metal centres was envisaged. In this work we explored variation of the metal centres in the secondary building units (SBUs of the MOFs as the first step to the testing and implementation of the design strategies. Carbazole, representing carbazoles which the major compounds that remain in hydrotreated fuel, was the target compound. Four MOFs of zinc (Zn-CDC-bpe), copper (Cu-CDC-bpe), nickel (Ni-CDC-bpe) and cobalt (Co-CDC-bpe) based on the formation of a dinuclear metal paddlewheel SBUs with the ligand 9H-Carbazole-3,6-dicarboxylic acid (H2CDC) and occupation of the axial positions of the paddlewheel by 1,2-Bis(4-pyridyl)ethane (bpe) to form porous networks were synthesized. A fifth MOF containing only CDC which forms a [Zn4O(O2C-R)5(O2HC-R)] SBU was also synthesized (Zn-CDC). The ligand H2CDC was inspired by the possibility of improving selectivity for carbazole via π–π interactions through the more preferred parallel-offset stacking as well as the possibility for further substitution of the carbazole N-H to add groups that improve selectivity. The sizes of the MOF cavities can then be controlled by choosing different lengths of ligands analogous to 1,2-Bis(4-pyridyl)ethane (bpe), e.g. 4,4’-bipyridine and pyrazine. All the MOFs showed good selectivity of carbazole. The Zn-CDC MOF also had good selectivity for the basic nitrogen-containing compounds tested: quinoline, isoquinoline, quinaldine and 1-naphthylamine. Its uptake of carbazole was also slightly higher. This was attributed to the presence of an unsaturated Zn site in the SBU. Adsorption in all the MOFs was primarily due to physisorption. It was concluded that the role of the metal centre does not play a significant role in the adsorption of carbazole besides providing a template for reticular synthesis. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2021
- Full Text: false
- Date Issued: 2021-12
- Authors: Dembaremba, Tendai O
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53630 , vital:45682
- Description: In this thesis, we present adsorptive removal of nitrogen-containing compounds from fuel oil as an alternative to complement conventional hydrotreatment to obtain ultra-low sulfur and nitrogen levels. This is in cognizance of the challenges nitrogen-containing compounds pose to the hydrotreatment process, particularly their inhibition and/or poisoning of the catalysts used in the process, of which basic nitrogen-containing compounds are the major culprits. Selectivity is the biggest challenge for adsorptive removal of nitrogen-containing compounds. We explore reticular synthesis of metal organic frameworks and the use of coordinatively unsaturated metal sites in 1-dimensional coordination polymers to achieve good selectivity for nitrogen-containing compounds. In the first part of the thesis, reticular synthesis of metal organic frameworks to control the size of the cavity, and strategically use the linkers and metal centres was envisaged. In this work we explored variation of the metal centres in the secondary building units (SBUs of the MOFs as the first step to the testing and implementation of the design strategies. Carbazole, representing carbazoles which the major compounds that remain in hydrotreated fuel, was the target compound. Four MOFs of zinc (Zn-CDC-bpe), copper (Cu-CDC-bpe), nickel (Ni-CDC-bpe) and cobalt (Co-CDC-bpe) based on the formation of a dinuclear metal paddlewheel SBUs with the ligand 9H-Carbazole-3,6-dicarboxylic acid (H2CDC) and occupation of the axial positions of the paddlewheel by 1,2-Bis(4-pyridyl)ethane (bpe) to form porous networks were synthesized. A fifth MOF containing only CDC which forms a [Zn4O(O2C-R)5(O2HC-R)] SBU was also synthesized (Zn-CDC). The ligand H2CDC was inspired by the possibility of improving selectivity for carbazole via π–π interactions through the more preferred parallel-offset stacking as well as the possibility for further substitution of the carbazole N-H to add groups that improve selectivity. The sizes of the MOF cavities can then be controlled by choosing different lengths of ligands analogous to 1,2-Bis(4-pyridyl)ethane (bpe), e.g. 4,4’-bipyridine and pyrazine. All the MOFs showed good selectivity of carbazole. The Zn-CDC MOF also had good selectivity for the basic nitrogen-containing compounds tested: quinoline, isoquinoline, quinaldine and 1-naphthylamine. Its uptake of carbazole was also slightly higher. This was attributed to the presence of an unsaturated Zn site in the SBU. Adsorption in all the MOFs was primarily due to physisorption. It was concluded that the role of the metal centre does not play a significant role in the adsorption of carbazole besides providing a template for reticular synthesis. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2021
- Full Text: false
- Date Issued: 2021-12
Optimization of liposomes for enhanced stability against degradation by gastrointestinal fluid content
- Authors: Scholtz, Carla Chleo
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54117 , vital:46305
- Description: Motivation: Liposomes are nanoparticulate carriers consisting of a hydrophobic bilayer and a hydrophilic core. Their application as drug carrier systems arises from their unique physiochemical structure, biocompatibility and biodegradability. Their biphasic nature is significant in the delivery of peptide and protein drug molecules as it is thus able to encompass both hydrophobic and hydrophilic molecules. Liposomes are actively being used for drug delivery intravenously. These formulations have been successful in reducing side effects and improving therapeutic efficacy. However, the intravenous route poses many challenges and is not the preferred route of administration amongst patients. The oral route of administration is non-invasive, and administration is of ease, therefore it is the preferred route of administration amongst patients, especially those with complex medicine regimes. Problem: The gastrointestinal tract is a harsh environment. In order for liposomes to maintain their integrity during their course they require a level of stability against gastric and intestinal fluids and its associated constituents such as gastric and pancreatic enzymes, low pH and bile acid. Methodology: Based on recommendations extrapolated from literature, the incorporation of a bile salt, sodium glycocholate, into liposomes in conjunction with coating the surface with chitosan was selected as the optimization strategies to enhance the stability of liposomes against degradation in the gastrointestinal tract. Bilosomes with encapsulated calce in were produced using the thin-film hydration method and coated with chitosan. An in vitrocalce in release assay was conducted in simulated gastric and intestinal fluids which presented with in vivo conditions in terms of pH and enzymes and additional constituents such as a bile salt. Stability was determined by the extent of digestion within the simulated fluids with time. Results: Characterization results suggested that the addition of chitosan and sodium glycocholate to the liposomal formulation has significant effects on the physiochemical properties. The colloidal dispersions could not retain their stability during storage which was noticeable during HRTEM. Despite optimization of the liposomes, in vitro studies showed significant release in both simulated gastric and intestinal fluids, with majority release seen in the presence of pepsin and pancreatic, at low pH and in the presence of bile acid. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Scholtz, Carla Chleo
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54117 , vital:46305
- Description: Motivation: Liposomes are nanoparticulate carriers consisting of a hydrophobic bilayer and a hydrophilic core. Their application as drug carrier systems arises from their unique physiochemical structure, biocompatibility and biodegradability. Their biphasic nature is significant in the delivery of peptide and protein drug molecules as it is thus able to encompass both hydrophobic and hydrophilic molecules. Liposomes are actively being used for drug delivery intravenously. These formulations have been successful in reducing side effects and improving therapeutic efficacy. However, the intravenous route poses many challenges and is not the preferred route of administration amongst patients. The oral route of administration is non-invasive, and administration is of ease, therefore it is the preferred route of administration amongst patients, especially those with complex medicine regimes. Problem: The gastrointestinal tract is a harsh environment. In order for liposomes to maintain their integrity during their course they require a level of stability against gastric and intestinal fluids and its associated constituents such as gastric and pancreatic enzymes, low pH and bile acid. Methodology: Based on recommendations extrapolated from literature, the incorporation of a bile salt, sodium glycocholate, into liposomes in conjunction with coating the surface with chitosan was selected as the optimization strategies to enhance the stability of liposomes against degradation in the gastrointestinal tract. Bilosomes with encapsulated calce in were produced using the thin-film hydration method and coated with chitosan. An in vitrocalce in release assay was conducted in simulated gastric and intestinal fluids which presented with in vivo conditions in terms of pH and enzymes and additional constituents such as a bile salt. Stability was determined by the extent of digestion within the simulated fluids with time. Results: Characterization results suggested that the addition of chitosan and sodium glycocholate to the liposomal formulation has significant effects on the physiochemical properties. The colloidal dispersions could not retain their stability during storage which was noticeable during HRTEM. Despite optimization of the liposomes, in vitro studies showed significant release in both simulated gastric and intestinal fluids, with majority release seen in the presence of pepsin and pancreatic, at low pH and in the presence of bile acid. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text:
- Date Issued: 2021-12