A comprehensive approach to scalability assessment of ICTD projects : a case study of ICT4RED
- Authors: Baduza, Gugulethu Qhawekazi
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178435 , vital:42939
- Description: Access restricted until April 2023. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Baduza, Gugulethu Qhawekazi
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178435 , vital:42939
- Description: Access restricted until April 2023. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2021
- Full Text:
- Date Issued: 2021-04
A critical analysis of how the potential of Dynamic Geometry Software as a visualisation tool may enhance the teaching of Mathematics
- Authors: Mavani, Beena Deepak
- Date: 2021-04
- Subjects: Mathematics -- Computer-assisted instruction , Geometry -- Study and teaching (Secondary) -- South Africa -- Mthatha , Manipulatives (Education) -- South Africa -- Mthatha , Information visualization , Mathematics teachers -- Training of -- South Africa -- Mthatha , GeoGebra Literacy Initiative Project (GLIP) , Dynamic Geometry Software (DGS)
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177192 , vital:42798 , 10.21504/10962/177192
- Description: Visualisation in the mathematics classroom has its own pedagogical value and plays a significant role in developing mathematical intuition, thought and ideas. Dynamic visualisation possibilities of current digital technologies afford new ways of teaching and learning mathematics. The freely available GeoGebra software package is highly interactive and makes use of powerful features to create objects that are dynamic, and which can be moved around on the computer screen for mathematical exploration. This research study was conceptualised within the GeoGebra Literacy Initiative Project (GLIP) – an ICT teacher development project in Mthatha in the Eastern Cape, South Africa. The focus of this study was on how GeoGebra could be used as a teaching tool by harnessing its powerful visualisation capacity. In the study, selected GLIP teachers collaboratively developed GeoGebra applets, then implemented and evaluated them. The research methodology took the form of action research cycles in which the design, implementation and evaluation of successive applets determined the data gathering and analysis process. My data consisted mainly of recorded observations and reflective interviews. The underlying theoretical foundation of this study lies in constructivism, which aligned well with the conceptual and analytical framework of Kilpatrick et al.’s (2001) description of teaching proficiency. An in-depth analysis of my classroom observations resulted in multiple narratives that illuminated how teachers harnessed the visualisation capabilities inherent in the software. My findings showed that dynamic visualisation and interactivity afforded by the use of technology are key enabling factors for teachers to enhance the visualisation of mathematical concepts. My analysis across participants also showed that technical difficulties often compromised the use of technology in the teaching of mathematics. The significance of this research is its contribution to the ongoing deliberations of visualisation and utilisation of technological resources, particularly through the empowerment of a community of teachers. The findings recognised that the integration of technology required appropriate training, proper planning and continuous support and resources for the teaching of mathematics. This action research provided insightful information on integrating Dynamic Geometry Software (DGS) tools in mathematics classrooms that could be useful to teachers and curriculum planners. , Thesis (PhD) -- Education, Education, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mavani, Beena Deepak
- Date: 2021-04
- Subjects: Mathematics -- Computer-assisted instruction , Geometry -- Study and teaching (Secondary) -- South Africa -- Mthatha , Manipulatives (Education) -- South Africa -- Mthatha , Information visualization , Mathematics teachers -- Training of -- South Africa -- Mthatha , GeoGebra Literacy Initiative Project (GLIP) , Dynamic Geometry Software (DGS)
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177192 , vital:42798 , 10.21504/10962/177192
- Description: Visualisation in the mathematics classroom has its own pedagogical value and plays a significant role in developing mathematical intuition, thought and ideas. Dynamic visualisation possibilities of current digital technologies afford new ways of teaching and learning mathematics. The freely available GeoGebra software package is highly interactive and makes use of powerful features to create objects that are dynamic, and which can be moved around on the computer screen for mathematical exploration. This research study was conceptualised within the GeoGebra Literacy Initiative Project (GLIP) – an ICT teacher development project in Mthatha in the Eastern Cape, South Africa. The focus of this study was on how GeoGebra could be used as a teaching tool by harnessing its powerful visualisation capacity. In the study, selected GLIP teachers collaboratively developed GeoGebra applets, then implemented and evaluated them. The research methodology took the form of action research cycles in which the design, implementation and evaluation of successive applets determined the data gathering and analysis process. My data consisted mainly of recorded observations and reflective interviews. The underlying theoretical foundation of this study lies in constructivism, which aligned well with the conceptual and analytical framework of Kilpatrick et al.’s (2001) description of teaching proficiency. An in-depth analysis of my classroom observations resulted in multiple narratives that illuminated how teachers harnessed the visualisation capabilities inherent in the software. My findings showed that dynamic visualisation and interactivity afforded by the use of technology are key enabling factors for teachers to enhance the visualisation of mathematical concepts. My analysis across participants also showed that technical difficulties often compromised the use of technology in the teaching of mathematics. The significance of this research is its contribution to the ongoing deliberations of visualisation and utilisation of technological resources, particularly through the empowerment of a community of teachers. The findings recognised that the integration of technology required appropriate training, proper planning and continuous support and resources for the teaching of mathematics. This action research provided insightful information on integrating Dynamic Geometry Software (DGS) tools in mathematics classrooms that could be useful to teachers and curriculum planners. , Thesis (PhD) -- Education, Education, 2021
- Full Text:
- Date Issued: 2021-04
A double-edged sword : the minimum wage and agrarian labour in the Eastern Cape, South Africa, 2003–2014
- Authors: Naidoo, Lalitha
- Date: 2021-04
- Subjects: Minimum wage -- South Africa -- Eastern Cape , Agricultural laborers -- South Africa -- Eastern Cape , Labor laws and legislation -- South Africa , Agricultural wages -- South Africa -- Eastern Cape , Agricultural laborers -- South Africa -- Eastern Cape -- Social conditions , Agricultural laborers -- Legal status, laws, etc. -- South Africa -- Eastern Cape , Agricultural laws and legislation -- South Africa -- Eastern Cape , Work environment -- South Africa -- Eastern Cape , Economics -- Sociological aspects , South Africa -- Politics and government -- 1994-
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177111 , vital:42791 , 10.21504/10962/177115
- Description: Statutory wage setting and the extension of labour laws to the South African agrarian labour market are path-breaking events that altered the unilateral power which agrarian employers had, under apartheid, to set low wages and harsh employment conditions. Yet, economic sociologists have shown little interest in the agrarian minimum wage in South Africa. Consequently, little to no sociological perspectives are available on the way in which statutory wages shape the setting of actual agrarian wages, employment conditions, labour relations and working and living conditions. At the same time, economic sociology’s neglect of agrarian minimum wages perpetuates the dominance of economics in minimum wage research, as well as the narrow cost-benefit analysis, and firm and employer-centric focus, deployed by both opponents of minimum wages in the neoclassical economics camp and supporters in the heterodox economics camp. The firm-centric focus also applies to the few labour relations scholars who focus on minimum wages. As a result, a wide body of empirical information is available and concentrated in the Global North, on low-waged, urban-based firms’ employment and labour relations strategies with the occasioning of minimum wage laws, with scant to non-existing information on rural-based workers’ experiences in the Global South, at least in the case of South Africa. This thesis addresses the lacuna in existing research, specifically by concentrating on agrarian workers’ narratives of the outcomes of minimum wages on actual wages and conditions, and experiences at the site of production and in the sphere of expanded social reproduction. The conceptual framework of the thesis is rooted in a critical realist meta-theory which directs inquiry towards the search for underlying causes of events with a sensitivity to the interaction of structure and agency, so as to develop explanations of events, which in turn encourage emancipatory thought and praxis. Within this framework, a political economy perspective of the agrarian minimum wage is charted, founded on an inter-disciplinary approach that incorporates economic sociology perspectives, which view markets as socio-political constructs, alongside a Marxist analysis of wages and the distinction between the value of labour and the value of labour power. Also relevant are segmentation labour market models where the focus is on segmentation in labour supply, demand and regulation, and institutional economics that highlights labour’s weak bargaining power in low-waged labour markets. Based on this analytical perspective, the South African agrarian minimum wage is seen as a necessary intervention stemming from post-apartheid uneven neoliberal restructuring processes, to address extremely low agrarian wages that pose threats to the ongoing generation of agrarian labour power. Low agrarian wages are located in unequal power relations in the workplace and are embedded in the totality of the low-waged agrarian labour market, composed of particular features in the supply-side of the labour market (the sphere of social reproduction of labour), the demand-side of the labour market (the site of production), and the forces of regulation (the labour relations regime). The thesis explores new ways of conceptualising minimum wages in the South African context, placing emphasis on the local agrarian labour market, and it highlights the agency of agrarian labour by revealing their struggles, working life and living conditions. In so doing, the research expands inquiry beyond economic “impact” at the level of the firm/employer to examine: (a) workers’ employment trends before and after the minimum wage was introduced, (b) the extent of changes in working and living conditions and labour relations, (c) the scope for workers in animating changes and their struggles and challenges, and (d) shifts in actual wages in relation to prescribed wage rates. Focussing on the aforementioned aspects represents an attempt in this thesis to build on themes, raised in heterodox economics studies, of minimum wages and their relationship to the social devaluation of low-waged work, inequalities in bargaining power, and justice. Based on a stratified sample of workers that included, among other variables, sex, geographical area and agricultural sub-sectors, original data was collected through 52 in-depth interviews, two focus group interviews (comprised of 10 workers), and 501 surveyed workers. The research did not find widespread job losses when minimum wages were introduced, as per neoclassical economics’ predictions. Nor did it find transitions from low- to high-road approaches in employment strategies and labour relations, as claimed by certain heterodox economists. Instead, the findings at the sites of production corroborate the uneven, mixed and contradictory findings of applied heterodox minimum wage studies on employment strategies, labour relations and wage settings. In this light, it is concluded that the agrarian minimum wage had layered outcomes for workers based on key findings, which include: (a) the minimum wage became the maximum wage as actual wages increased and clustered at the prescribed wage rate; (b) a level of gender wage parity close to the level of the prevailing prescribed minimum wage was found, but an overall gendered pattern to low-waged employment surfaced and manifested differently at sub-sector and enterprise levels; (c) though no changes were found in the way work was organised and how workers executed their tasks alongside no fundamental changes in the social relations of production, statutory minimum wages and limitations on working hours did reduce the hours of work and the existence of unpaid overtime work in certain sub-sectors such as livestock and dairy workplaces, through worker and employer initiatives (yet, at the same time, work intensification in compressed working hours appeared in the sample in other worksites, for example citrus workplaces); (d) authoritarian labour relations existed in varying depths and forms, based on sub-sector and enterprise characteristics, which shaped the propensity and scope for worker action; and (e) the layered outcomes of the agrarian minimum wage were felt at the site of social reproduction, where it brought a measure of relief for sampled workers; however, it was chronically inadequate to allow workers to meet their subsistence needs comprehensively. The research findings also highlight sub-sectoral complexities in changing employment and labour relations strategies from low- to high-road approaches in the agrarian sector. The layered outcomes of minimum wages for agrarian workers stems from the combined and uneven amalgamation of pre-existing and new conditions and relations consequent to neoliberalising processes in the agrarian political economy as well as the low minimum wage-setting. The thesis thus argues that the mixed outcomes reflect the layered character of the minimum wage as a conversion factor, which in turn equates to a layered notion of justice. This is because, on the one hand, the minimum wage ameliorates the plight of agrarian labour but, on the other hand, and given the bulwark of authoritarianism, pre-existing conditions and neoliberalising processes, the collective vulnerabilities in the agrarian labour market have expanded and may be intensifying. The agrarian minimum wage acts as a double-edged sword in contexts of mixed and layered outcomes for agrarian labour. A layered perspective of the conversion factor of a minimum wage exposes the possibilities and limitations of statutory wages as a conversion factor, based on context, and identifies the limits and possibilities for worker mobilisation and action. In the case of this research, the agrarian minimum wage deals in limited fashion with the value of labour power because of the initial and subsequent low settings; the minimum wage does not deal with class exploitation and the value of labour, although it sets the frame for instigating basic labour standards. The implications of a layered conversion potential of low minimum wage-settings are profound for conceptualising, theorising and researching the link between statutory wages and justice, with respect to the value of labour power and the value of labour. Future research on the minimum wage based on a Marxist reading of wages and located in real labour markets, strengthens heterodox approaches by deepening theories on the relationship between statutory wages, justice and production. , Thesis (PhD) -- Faculty of Humanities, Department of Sociology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Naidoo, Lalitha
- Date: 2021-04
- Subjects: Minimum wage -- South Africa -- Eastern Cape , Agricultural laborers -- South Africa -- Eastern Cape , Labor laws and legislation -- South Africa , Agricultural wages -- South Africa -- Eastern Cape , Agricultural laborers -- South Africa -- Eastern Cape -- Social conditions , Agricultural laborers -- Legal status, laws, etc. -- South Africa -- Eastern Cape , Agricultural laws and legislation -- South Africa -- Eastern Cape , Work environment -- South Africa -- Eastern Cape , Economics -- Sociological aspects , South Africa -- Politics and government -- 1994-
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177111 , vital:42791 , 10.21504/10962/177115
- Description: Statutory wage setting and the extension of labour laws to the South African agrarian labour market are path-breaking events that altered the unilateral power which agrarian employers had, under apartheid, to set low wages and harsh employment conditions. Yet, economic sociologists have shown little interest in the agrarian minimum wage in South Africa. Consequently, little to no sociological perspectives are available on the way in which statutory wages shape the setting of actual agrarian wages, employment conditions, labour relations and working and living conditions. At the same time, economic sociology’s neglect of agrarian minimum wages perpetuates the dominance of economics in minimum wage research, as well as the narrow cost-benefit analysis, and firm and employer-centric focus, deployed by both opponents of minimum wages in the neoclassical economics camp and supporters in the heterodox economics camp. The firm-centric focus also applies to the few labour relations scholars who focus on minimum wages. As a result, a wide body of empirical information is available and concentrated in the Global North, on low-waged, urban-based firms’ employment and labour relations strategies with the occasioning of minimum wage laws, with scant to non-existing information on rural-based workers’ experiences in the Global South, at least in the case of South Africa. This thesis addresses the lacuna in existing research, specifically by concentrating on agrarian workers’ narratives of the outcomes of minimum wages on actual wages and conditions, and experiences at the site of production and in the sphere of expanded social reproduction. The conceptual framework of the thesis is rooted in a critical realist meta-theory which directs inquiry towards the search for underlying causes of events with a sensitivity to the interaction of structure and agency, so as to develop explanations of events, which in turn encourage emancipatory thought and praxis. Within this framework, a political economy perspective of the agrarian minimum wage is charted, founded on an inter-disciplinary approach that incorporates economic sociology perspectives, which view markets as socio-political constructs, alongside a Marxist analysis of wages and the distinction between the value of labour and the value of labour power. Also relevant are segmentation labour market models where the focus is on segmentation in labour supply, demand and regulation, and institutional economics that highlights labour’s weak bargaining power in low-waged labour markets. Based on this analytical perspective, the South African agrarian minimum wage is seen as a necessary intervention stemming from post-apartheid uneven neoliberal restructuring processes, to address extremely low agrarian wages that pose threats to the ongoing generation of agrarian labour power. Low agrarian wages are located in unequal power relations in the workplace and are embedded in the totality of the low-waged agrarian labour market, composed of particular features in the supply-side of the labour market (the sphere of social reproduction of labour), the demand-side of the labour market (the site of production), and the forces of regulation (the labour relations regime). The thesis explores new ways of conceptualising minimum wages in the South African context, placing emphasis on the local agrarian labour market, and it highlights the agency of agrarian labour by revealing their struggles, working life and living conditions. In so doing, the research expands inquiry beyond economic “impact” at the level of the firm/employer to examine: (a) workers’ employment trends before and after the minimum wage was introduced, (b) the extent of changes in working and living conditions and labour relations, (c) the scope for workers in animating changes and their struggles and challenges, and (d) shifts in actual wages in relation to prescribed wage rates. Focussing on the aforementioned aspects represents an attempt in this thesis to build on themes, raised in heterodox economics studies, of minimum wages and their relationship to the social devaluation of low-waged work, inequalities in bargaining power, and justice. Based on a stratified sample of workers that included, among other variables, sex, geographical area and agricultural sub-sectors, original data was collected through 52 in-depth interviews, two focus group interviews (comprised of 10 workers), and 501 surveyed workers. The research did not find widespread job losses when minimum wages were introduced, as per neoclassical economics’ predictions. Nor did it find transitions from low- to high-road approaches in employment strategies and labour relations, as claimed by certain heterodox economists. Instead, the findings at the sites of production corroborate the uneven, mixed and contradictory findings of applied heterodox minimum wage studies on employment strategies, labour relations and wage settings. In this light, it is concluded that the agrarian minimum wage had layered outcomes for workers based on key findings, which include: (a) the minimum wage became the maximum wage as actual wages increased and clustered at the prescribed wage rate; (b) a level of gender wage parity close to the level of the prevailing prescribed minimum wage was found, but an overall gendered pattern to low-waged employment surfaced and manifested differently at sub-sector and enterprise levels; (c) though no changes were found in the way work was organised and how workers executed their tasks alongside no fundamental changes in the social relations of production, statutory minimum wages and limitations on working hours did reduce the hours of work and the existence of unpaid overtime work in certain sub-sectors such as livestock and dairy workplaces, through worker and employer initiatives (yet, at the same time, work intensification in compressed working hours appeared in the sample in other worksites, for example citrus workplaces); (d) authoritarian labour relations existed in varying depths and forms, based on sub-sector and enterprise characteristics, which shaped the propensity and scope for worker action; and (e) the layered outcomes of the agrarian minimum wage were felt at the site of social reproduction, where it brought a measure of relief for sampled workers; however, it was chronically inadequate to allow workers to meet their subsistence needs comprehensively. The research findings also highlight sub-sectoral complexities in changing employment and labour relations strategies from low- to high-road approaches in the agrarian sector. The layered outcomes of minimum wages for agrarian workers stems from the combined and uneven amalgamation of pre-existing and new conditions and relations consequent to neoliberalising processes in the agrarian political economy as well as the low minimum wage-setting. The thesis thus argues that the mixed outcomes reflect the layered character of the minimum wage as a conversion factor, which in turn equates to a layered notion of justice. This is because, on the one hand, the minimum wage ameliorates the plight of agrarian labour but, on the other hand, and given the bulwark of authoritarianism, pre-existing conditions and neoliberalising processes, the collective vulnerabilities in the agrarian labour market have expanded and may be intensifying. The agrarian minimum wage acts as a double-edged sword in contexts of mixed and layered outcomes for agrarian labour. A layered perspective of the conversion factor of a minimum wage exposes the possibilities and limitations of statutory wages as a conversion factor, based on context, and identifies the limits and possibilities for worker mobilisation and action. In the case of this research, the agrarian minimum wage deals in limited fashion with the value of labour power because of the initial and subsequent low settings; the minimum wage does not deal with class exploitation and the value of labour, although it sets the frame for instigating basic labour standards. The implications of a layered conversion potential of low minimum wage-settings are profound for conceptualising, theorising and researching the link between statutory wages and justice, with respect to the value of labour power and the value of labour. Future research on the minimum wage based on a Marxist reading of wages and located in real labour markets, strengthens heterodox approaches by deepening theories on the relationship between statutory wages, justice and production. , Thesis (PhD) -- Faculty of Humanities, Department of Sociology, 2021
- Full Text:
- Date Issued: 2021-04
A mineralogical study of phosphate mineralisation in the Nkombwa Hill Carbonatite
- Authors: Mapholi, Thendo
- Date: 2021-10-29
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/294797 , vital:57256
- Description: Thesis embargoed. Release date October 2023. , Thesis (MSc) -- Faculty of Science, Geology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Mapholi, Thendo
- Date: 2021-10-29
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/294797 , vital:57256
- Description: Thesis embargoed. Release date October 2023. , Thesis (MSc) -- Faculty of Science, Geology, 2021
- Full Text:
- Date Issued: 2021-10-29
A narrative study of students’ and staff’s experiences of living with HIV and AIDS at Rhodes University
- Authors: Tsope, Lindiwe
- Date: 2021-04
- Subjects: AIDS (Disease) South Africa Makhanda , HIV infections South Africa Makhanda , College students Health and hygiene South Africa Makhanda , Universities and colleges South Africa Makhanda Employees Health and hygiene , Stigma (Social psychology) , AIDS (Disease) Social aspects South Africa Makhanda , HIV infections Social aspects South Africa Makhanda , AIDS (Disease) Psychological aspects , HIV infections Psychological aspects , Health counseling South Africa Makhanda , Discourse analysis, Narrative
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/176894 , vital:42769 , 10.21504/10962/176894
- Description: A narrative study of students’ and staff’s experiences of living with HIV and AIDS at Rhodes University Research on HIV and AIDS in university settings, especially research exploring the experience of living with the disease, has been minimal. As a response to the knowledge and research gaps, this thesis is a qualitative study involving students and staff living with HIV (LWH) and accessing treatment (ART) at the Rhodes University Health Care Centre. This study explored the personal and social symbolisms as well as meanings attached to living with HIV, through in-depth interviews with ten students and staff living with HIV, all purposively sampled and recruited through the Rhodes University Health Care Centre. Using social constructionism, symbolic interactionism and the theory of biographical disruption, the narratives revealed a positive and inspirational side of living with HIV and AIDS – especially emphasizing that PLWHA do not have to surrender to the deadly narrative of the disease. It became evident that stigma, both internal and external, largely influences illness narratives. Furthermore, the study revealed the social reconstruction of life narratives both in order to understand the illness in terms of past social experiences and to reaffirm the impression that life has a course and the self has a purpose. All participants found that accessing treatment from the Rhodes University Health Care Centre positively influenced their experiences of adherence and reconstruction of narratives. The study indicates that HIV-related interventions in place at the university need to pay more attention to the psychosocial needs of PLWH, involvement of PWLH, as well as keeping up with the continuously changing global HIV narrative. The study argues for more attention to in-depth experiences and personal narratives in HIV and AIDS, and PLWHA education at Rhodes University. , Thesis (PhD) -- Humanities, Department of Sociology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Tsope, Lindiwe
- Date: 2021-04
- Subjects: AIDS (Disease) South Africa Makhanda , HIV infections South Africa Makhanda , College students Health and hygiene South Africa Makhanda , Universities and colleges South Africa Makhanda Employees Health and hygiene , Stigma (Social psychology) , AIDS (Disease) Social aspects South Africa Makhanda , HIV infections Social aspects South Africa Makhanda , AIDS (Disease) Psychological aspects , HIV infections Psychological aspects , Health counseling South Africa Makhanda , Discourse analysis, Narrative
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/176894 , vital:42769 , 10.21504/10962/176894
- Description: A narrative study of students’ and staff’s experiences of living with HIV and AIDS at Rhodes University Research on HIV and AIDS in university settings, especially research exploring the experience of living with the disease, has been minimal. As a response to the knowledge and research gaps, this thesis is a qualitative study involving students and staff living with HIV (LWH) and accessing treatment (ART) at the Rhodes University Health Care Centre. This study explored the personal and social symbolisms as well as meanings attached to living with HIV, through in-depth interviews with ten students and staff living with HIV, all purposively sampled and recruited through the Rhodes University Health Care Centre. Using social constructionism, symbolic interactionism and the theory of biographical disruption, the narratives revealed a positive and inspirational side of living with HIV and AIDS – especially emphasizing that PLWHA do not have to surrender to the deadly narrative of the disease. It became evident that stigma, both internal and external, largely influences illness narratives. Furthermore, the study revealed the social reconstruction of life narratives both in order to understand the illness in terms of past social experiences and to reaffirm the impression that life has a course and the self has a purpose. All participants found that accessing treatment from the Rhodes University Health Care Centre positively influenced their experiences of adherence and reconstruction of narratives. The study indicates that HIV-related interventions in place at the university need to pay more attention to the psychosocial needs of PLWH, involvement of PWLH, as well as keeping up with the continuously changing global HIV narrative. The study argues for more attention to in-depth experiences and personal narratives in HIV and AIDS, and PLWHA education at Rhodes University. , Thesis (PhD) -- Humanities, Department of Sociology, 2021
- Full Text:
- Date Issued: 2021-04
A novel Arf GTPase assay for antimalarial drug discovery
- Authors: Swart, Tarryn
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178558 , vital:42950
- Description: Access restricted until April 2022. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Swart, Tarryn
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178558 , vital:42950
- Description: Access restricted until April 2022. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
A social realist study of employability development in engineering education
- Authors: Nudelman, Gabrielle
- Date: 2018
- Subjects: Critical realism , Electrical engineering -- Study and teaching (Higher) -- South Africa -- Cape Town , Employability , Career education -- South Africa -- Cape Town , School-to-work transition -- South Africa -- Cape Town
- Language: English
- Type: thesis , text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62884 , vital:28307
- Description: This qualitative case study of a course pairing offered to final-year electrical engineering students at the University of Cape Town in 2015 was undertaken in order to better understand the ways in which participation in undergraduate courses can prepare engineering students for the workplace. The course pairing consisted of New Venture Planning and Professional Communication Studies. While the former aimed to expose students to the knowledge relating to starting a new business, the latter focused on teaching students how to create written and oral texts to support such an endeavour. Using Roy Bhaskar’s critical realism as a theoretical underlabourer, the study develops understandings regarding the generative mechanisms at work during the two courses. In support of this, the study posits an understanding of employability that moves beyond the acquisition of discrete workplace skills. Rather, employability is conceptualised as discursive transformation, with students being deemed “work-ready” when they develop discursive identities as engineers. Data generation took place by means of focus group and individual interviews, ethnographic observation and documentary research. Margaret Archer’s social realist tools – in particular, analytical dualism and the morphogenetic framework were used to trace the students’ transformations over the course pairing. It was argued that those students who developed discursive identities of engineers were those who, in Archer’s terms, emerged as social actors at the end of the course pairing. Two characteristics of the courses were found to enable this transformation: those parts that promoted deepened understanding of what the role of “engineer” entailed and the parts that provided spaces for students to develop their own personal identities. The findings of the study indicated that discursive identities as engineers were more likely to be developed through the group work and spaces for reflection engendered by the courses than as a result of the formal curriculum. The implications of the research are that, while a focus on employability in engineering education is valid and productive, this needs to be supported by opportunities for authentic learning experiences which afford students the opportunity to engage in learning that promotes real-life application of knowledge. , Thesis (PhD)--Rhodes University, Faculty of Education, Education, 2018
- Full Text:
- Date Issued: 2018
- Authors: Nudelman, Gabrielle
- Date: 2018
- Subjects: Critical realism , Electrical engineering -- Study and teaching (Higher) -- South Africa -- Cape Town , Employability , Career education -- South Africa -- Cape Town , School-to-work transition -- South Africa -- Cape Town
- Language: English
- Type: thesis , text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62884 , vital:28307
- Description: This qualitative case study of a course pairing offered to final-year electrical engineering students at the University of Cape Town in 2015 was undertaken in order to better understand the ways in which participation in undergraduate courses can prepare engineering students for the workplace. The course pairing consisted of New Venture Planning and Professional Communication Studies. While the former aimed to expose students to the knowledge relating to starting a new business, the latter focused on teaching students how to create written and oral texts to support such an endeavour. Using Roy Bhaskar’s critical realism as a theoretical underlabourer, the study develops understandings regarding the generative mechanisms at work during the two courses. In support of this, the study posits an understanding of employability that moves beyond the acquisition of discrete workplace skills. Rather, employability is conceptualised as discursive transformation, with students being deemed “work-ready” when they develop discursive identities as engineers. Data generation took place by means of focus group and individual interviews, ethnographic observation and documentary research. Margaret Archer’s social realist tools – in particular, analytical dualism and the morphogenetic framework were used to trace the students’ transformations over the course pairing. It was argued that those students who developed discursive identities of engineers were those who, in Archer’s terms, emerged as social actors at the end of the course pairing. Two characteristics of the courses were found to enable this transformation: those parts that promoted deepened understanding of what the role of “engineer” entailed and the parts that provided spaces for students to develop their own personal identities. The findings of the study indicated that discursive identities as engineers were more likely to be developed through the group work and spaces for reflection engendered by the courses than as a result of the formal curriculum. The implications of the research are that, while a focus on employability in engineering education is valid and productive, this needs to be supported by opportunities for authentic learning experiences which afford students the opportunity to engage in learning that promotes real-life application of knowledge. , Thesis (PhD)--Rhodes University, Faculty of Education, Education, 2018
- Full Text:
- Date Issued: 2018
Accountability in the global health regime : a critical examination of the institutional policy and practice of the global fund to fight HIV/AIDS, tuberculosis and malaria partnership programme in Ghana
- Authors: Onokwai, John Chukwuemeka
- Date: 2021-04
- Subjects: World health , Global Fund to Fight AIDS, Tuberculosis, and Malaria -- Administration , Public-private sector cooperation -- Political aspects , Public-private sector cooperation -- Social aspects , Public-private sector cooperation -- Administration , Medical policy -- Ghana , Public health laws, International , Ghana -- Social conditions
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177099 , vital:42790 , 10.21504/10962/177099
- Description: The overarching objective of this thesis is to undertake a critical examination of the institutional accountability policy and practice of the Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund) in the context of its partnership programme in Ghana. The Global Fund is a global public-private partnership (GPPP) in health engaged in public health policy processes worldwide. As a GPPP, the policy mandate that underpins its global response to fight the aforementioned diseases requires it to enter into partnerships with recipient countries to finance their national health policy responses and strategies to tackle these diseases. Situating accountability within the context of the shift from an international health to a global health regime, the study argues that the emergence of GPPPs in health and the formal policy mandate and decision-making powers they exercise have had knock-on consequences for understanding accountability in the global health regime. This is because while the understanding of accountability for public health policy processes in the international health regime revolved solely around state-based and state-led accountability processes, it is no longer so in current global health regime. Since these GPPPs are not states, they derive their understanding of accountability from the nature and character of their individual policy and practice arrangements. However, despite contestation around the Global Fund’s accountability in global health literature, this literature has little to say on the question of how the Global Fund itself (as a partnership organisation) understands accountability in policy and how this understanding informs its practice in specific settings of global health. Thus, this study contributes to literature on GPPPs’ accountability in global health by specifically exploring how the Global Fund understands accountability in policy and how this understanding informs its accountability in practice, in particular in relationship to its implications for country ownership of health policy in Ghana. Drawing on fieldwork undertaken in Ghana, and guided by a critical political economy approach, this study will demonstrate how: 1) the Global Fund’s institutional policy and practice arrangements undermine accountability to the government and to those affected by their activities; 2) the Global Fund’s practice of country ownership is reflective of conditional ownership despite the fact that the Global Fund claims to promote country ownership as a core principle of its accountability practice in aid recipient countries; and 3) the accountability policy and practice instruments of the Global Fund are not politically neutral, but are rather a function of relations of power. To improve the ability of Ghana (and other recipient countries) to own their developmental policies, a reordering of global economic relations is needed, with a renewed emphasis and focus on economic justice and human rights. Such a reordering will improve the material capabilities (control of and access to global centres of production, finance and technology) of aid recipient countries. This will empower Ghana (and other recipient countries) to play a more dominant, rather than a subsidiary role in how the global health landscape is organised and financed and in policy processes undertaken by global health policy institutions like the Global Fund. In this way, Ghana (and other developing countries) will be able to limit and mitigate the dominance and influence of powerful donors who shape the institutional policy and practice arrangements of global health policy institutions like the Global Fund. , Thesis (PhD) -- Faculty of Humanities, Department of Political and International Studies, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Onokwai, John Chukwuemeka
- Date: 2021-04
- Subjects: World health , Global Fund to Fight AIDS, Tuberculosis, and Malaria -- Administration , Public-private sector cooperation -- Political aspects , Public-private sector cooperation -- Social aspects , Public-private sector cooperation -- Administration , Medical policy -- Ghana , Public health laws, International , Ghana -- Social conditions
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177099 , vital:42790 , 10.21504/10962/177099
- Description: The overarching objective of this thesis is to undertake a critical examination of the institutional accountability policy and practice of the Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund) in the context of its partnership programme in Ghana. The Global Fund is a global public-private partnership (GPPP) in health engaged in public health policy processes worldwide. As a GPPP, the policy mandate that underpins its global response to fight the aforementioned diseases requires it to enter into partnerships with recipient countries to finance their national health policy responses and strategies to tackle these diseases. Situating accountability within the context of the shift from an international health to a global health regime, the study argues that the emergence of GPPPs in health and the formal policy mandate and decision-making powers they exercise have had knock-on consequences for understanding accountability in the global health regime. This is because while the understanding of accountability for public health policy processes in the international health regime revolved solely around state-based and state-led accountability processes, it is no longer so in current global health regime. Since these GPPPs are not states, they derive their understanding of accountability from the nature and character of their individual policy and practice arrangements. However, despite contestation around the Global Fund’s accountability in global health literature, this literature has little to say on the question of how the Global Fund itself (as a partnership organisation) understands accountability in policy and how this understanding informs its practice in specific settings of global health. Thus, this study contributes to literature on GPPPs’ accountability in global health by specifically exploring how the Global Fund understands accountability in policy and how this understanding informs its accountability in practice, in particular in relationship to its implications for country ownership of health policy in Ghana. Drawing on fieldwork undertaken in Ghana, and guided by a critical political economy approach, this study will demonstrate how: 1) the Global Fund’s institutional policy and practice arrangements undermine accountability to the government and to those affected by their activities; 2) the Global Fund’s practice of country ownership is reflective of conditional ownership despite the fact that the Global Fund claims to promote country ownership as a core principle of its accountability practice in aid recipient countries; and 3) the accountability policy and practice instruments of the Global Fund are not politically neutral, but are rather a function of relations of power. To improve the ability of Ghana (and other recipient countries) to own their developmental policies, a reordering of global economic relations is needed, with a renewed emphasis and focus on economic justice and human rights. Such a reordering will improve the material capabilities (control of and access to global centres of production, finance and technology) of aid recipient countries. This will empower Ghana (and other recipient countries) to play a more dominant, rather than a subsidiary role in how the global health landscape is organised and financed and in policy processes undertaken by global health policy institutions like the Global Fund. In this way, Ghana (and other developing countries) will be able to limit and mitigate the dominance and influence of powerful donors who shape the institutional policy and practice arrangements of global health policy institutions like the Global Fund. , Thesis (PhD) -- Faculty of Humanities, Department of Political and International Studies, 2021
- Full Text:
- Date Issued: 2021-04
An Archive of Upset : the Shift from Commissioning to Curating through South Africa’s Representations at the Bienal de São Paulo and the Interstitial Nexus of Leonard Tshehla Mohapi Matsoso
- Authors: Dantas, Nancy Isabel
- Date: 2021-04
- Subjects: Bienal Internacional de São Paulo , Curatorship , Art -- Commissioning , Art -- Political aspects , Matsoso, Leonard Tshehla Mohapi
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174492 , vital:42482 , https://doi.org/10.21504/10962/174492
- Description: This thesis explores the distinction between commissioning and curating, adopting the Bienal de São Paulo (or Bienal) as its conceptual propeller and point of departure. The thesis regards exhibitions as palimpsests, in other words, platforms built on previous conscious or sublimated models, beyond the Venetian model inaugurated in 1895. By looking at world expositions, particularly the Cape presence at the Colonial and Indian Exhibition of 1886, this project traces a lineage of commissioners, from Sir Henry Cole to Sydney Cowper through to the Director of the Pretoria Art Museum, Albert Werth. It distinguishes these men, their vision and allegiances from the curatorial model instantiated in South Africa by the late Okwui Enwezor as a consequence of the Second Johannesburg Biennale, held in 1997. The aim of this research has been to provide a partial but crucial account of this shift, and to remain attentive to the silences and deletions, to what happens in the interstice, at transitionary moments of ‘betweenness.’ I ask that readers consider the 1979 Bienal as an instance of an interstice where the occluded and silenced ghost of modernist artist Leonard Tshehla Mohapi Matsoso, who represented South Africa at the 1973 edition of the Bienal, garnering a substantial award for his work in drawing, resides. Matsoso was the first and only Black South African artist to receive this accolade. This thesis posits that Matsoso’s absence from the exhibition in 1979, an exhibition where he would rightly have featured, constitutes a curatorial haunting, wedged in the archive of the Bienal’s history, and an opportunity for revision and evaluation of commissioning vis-àvis curating. In reading the exhibition histories’ archive “along the grain” (Stoler 2002), the commissioner emerges as a man of letters, a privileged social category found in the archive; a colonial authority whose status was founded as much on his display of European learning as on his studied ignorance of local knowledge; an implementer of the taxonomic state and modernist art historical canon (in the case of Werth); a cultivator of the fine arts of deference, dissemblance and persuasion. At a later stage and moment of dissonance and disruption, the independent curator emerges to reconsider, question and expand the canon, distancing him/herself from the (South African) State to serve the artist or artists and a wider community. This research aims to contribute, albeit in a small way, to a reappraisal of the position of Leonard Tshehla Mohapi Matsoso in South African modernism, and the distinction between commissioning and curating. , Thesis (PhD)--Rhodes University, Faculty of Humanities, Department of Fine Art, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Dantas, Nancy Isabel
- Date: 2021-04
- Subjects: Bienal Internacional de São Paulo , Curatorship , Art -- Commissioning , Art -- Political aspects , Matsoso, Leonard Tshehla Mohapi
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174492 , vital:42482 , https://doi.org/10.21504/10962/174492
- Description: This thesis explores the distinction between commissioning and curating, adopting the Bienal de São Paulo (or Bienal) as its conceptual propeller and point of departure. The thesis regards exhibitions as palimpsests, in other words, platforms built on previous conscious or sublimated models, beyond the Venetian model inaugurated in 1895. By looking at world expositions, particularly the Cape presence at the Colonial and Indian Exhibition of 1886, this project traces a lineage of commissioners, from Sir Henry Cole to Sydney Cowper through to the Director of the Pretoria Art Museum, Albert Werth. It distinguishes these men, their vision and allegiances from the curatorial model instantiated in South Africa by the late Okwui Enwezor as a consequence of the Second Johannesburg Biennale, held in 1997. The aim of this research has been to provide a partial but crucial account of this shift, and to remain attentive to the silences and deletions, to what happens in the interstice, at transitionary moments of ‘betweenness.’ I ask that readers consider the 1979 Bienal as an instance of an interstice where the occluded and silenced ghost of modernist artist Leonard Tshehla Mohapi Matsoso, who represented South Africa at the 1973 edition of the Bienal, garnering a substantial award for his work in drawing, resides. Matsoso was the first and only Black South African artist to receive this accolade. This thesis posits that Matsoso’s absence from the exhibition in 1979, an exhibition where he would rightly have featured, constitutes a curatorial haunting, wedged in the archive of the Bienal’s history, and an opportunity for revision and evaluation of commissioning vis-àvis curating. In reading the exhibition histories’ archive “along the grain” (Stoler 2002), the commissioner emerges as a man of letters, a privileged social category found in the archive; a colonial authority whose status was founded as much on his display of European learning as on his studied ignorance of local knowledge; an implementer of the taxonomic state and modernist art historical canon (in the case of Werth); a cultivator of the fine arts of deference, dissemblance and persuasion. At a later stage and moment of dissonance and disruption, the independent curator emerges to reconsider, question and expand the canon, distancing him/herself from the (South African) State to serve the artist or artists and a wider community. This research aims to contribute, albeit in a small way, to a reappraisal of the position of Leonard Tshehla Mohapi Matsoso in South African modernism, and the distinction between commissioning and curating. , Thesis (PhD)--Rhodes University, Faculty of Humanities, Department of Fine Art, 2021
- Full Text:
- Date Issued: 2021-04
An evaluation of synergistic interactions between feruloyl esterases and xylanases during the hydrolysis of various pre-treated agricultural residues
- Authors: Mkabayi, Lithalethu
- Date: 2021-04
- Subjects: Esterases , Xylanases , Hydrolysis , Agricultural wastes -- Recycling , Enzymes , Lignocellulose -- Biodegradation , Escherichia coli , Oligosaccharides , Hydroxycinnamic acids
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178224 , vital:42922 , 10.21504/10962/178224
- Description: Agricultural residues are readily available and inexpensive renewable resources that can be used as raw materials for the production of value-added chemicals. The application of enzymes to facilitate the degradation of agricultural residues has long been considered the most environmentally friendly strategy for converting this material into good quality value-added chemicals. However, agricultural residues are typically lignocellulosic in composition and recalcitrant to enzymatic hydrolysis. Due to this recalcitrant nature, the complete degradation of biomass residues requires the synergistic action of a broad range of enzymes. The development and optimisation of synergistic enzyme cocktails is an effective approach for achieving high hydrolysis efficiency of lignocellulosic biomass. The aim of the current study was to evaluate the synergistic interactions between two termite metagenome-derived feruloyl esterases (FAE6 and FAE5) and endo-xylanases for the production of hydroxycinnamic acids and xylo-oligosaccharides (XOS) from model substrates, and untreated and pre-treated agricultural residues. Firstly, the two fae genes were heterologously expressed in Escherichia coli, and the recombinant enzymes were purified to homogeneity. The biochemical properties of the purified recombinant FAEs and xylanases (XT6 and Xyn11) were then assessed to determine the factors which influenced their activities and to select suitable operating conditions for synergy studies. An optimal protein loading ratio of xylanases to FAEs required to maximise the release of both reducing sugar and ferulic acid (FA) was established using 0.5% (w/v) insoluble wheat arabinoxylan (a model substrate). The enzyme combination of 66% xylanase and 33% FAE (on a protein loading basis) produced the highest amounts of reducing sugars and FA. The enzyme combination of XT6 (GH10 xylanase) and FAE5 or FAE6 liberated the highest amount of FA while a combination of Xyn11 (GH11 xylanase) and FAE5 or FAE6 produced the highest reducing sugar content. The synergistic interactions which were established between the xylanases and FAEs were further investigated using agricultural residues (corn cobs, rice straw and sugarcane bagasse). The three substrates were subjected to hydrothermal and dilute acid pre-treatment prior to synergy studies. It is generally known that, during pre-treatment, many compounds can be produced which may influence enzymatic hydrolysis. The effects of these by-products were assessed and it was found that lignin and its degradation products were the most inhibitory to the FAEs. The optimised enzyme cocktail was then applied to 1% (w/v) of untreated and pre-treated substrates for the efficient production of XOS and hydroxycinnamic acids. A significant improvement in xylanase substrate degradation was observed, especially with the combination of 66% Xyn11 and 33% FAE6 which displayed an improvement in reducing sugars of approximately 1.9-fold and 3.4-fold for hydrothermal and acid pre-treated corn cobs (compared to when Xyn11 was used alone), respectively. The study demonstrated that pre-treatment substantially enhanced the enzymatic hydrolysis of corn cobs and rice straw. Analysis of the hydrolysate product profiles revealed that the optimised enzyme cocktail displayed great potential for releasing XOS with a low degree of polymerisation. In conclusion, this study provided significant insights into the mechanism of synergistic interactions between xylanases and metagenome-derived FAEs during the hydrolysis of various substrates. The study also demonstrated that optimised enzyme cocktails combined with low severity pre-treatment can facilitate the potential use of xylan-rich lignocellulosic biomass for the production of valuable products in the future. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mkabayi, Lithalethu
- Date: 2021-04
- Subjects: Esterases , Xylanases , Hydrolysis , Agricultural wastes -- Recycling , Enzymes , Lignocellulose -- Biodegradation , Escherichia coli , Oligosaccharides , Hydroxycinnamic acids
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178224 , vital:42922 , 10.21504/10962/178224
- Description: Agricultural residues are readily available and inexpensive renewable resources that can be used as raw materials for the production of value-added chemicals. The application of enzymes to facilitate the degradation of agricultural residues has long been considered the most environmentally friendly strategy for converting this material into good quality value-added chemicals. However, agricultural residues are typically lignocellulosic in composition and recalcitrant to enzymatic hydrolysis. Due to this recalcitrant nature, the complete degradation of biomass residues requires the synergistic action of a broad range of enzymes. The development and optimisation of synergistic enzyme cocktails is an effective approach for achieving high hydrolysis efficiency of lignocellulosic biomass. The aim of the current study was to evaluate the synergistic interactions between two termite metagenome-derived feruloyl esterases (FAE6 and FAE5) and endo-xylanases for the production of hydroxycinnamic acids and xylo-oligosaccharides (XOS) from model substrates, and untreated and pre-treated agricultural residues. Firstly, the two fae genes were heterologously expressed in Escherichia coli, and the recombinant enzymes were purified to homogeneity. The biochemical properties of the purified recombinant FAEs and xylanases (XT6 and Xyn11) were then assessed to determine the factors which influenced their activities and to select suitable operating conditions for synergy studies. An optimal protein loading ratio of xylanases to FAEs required to maximise the release of both reducing sugar and ferulic acid (FA) was established using 0.5% (w/v) insoluble wheat arabinoxylan (a model substrate). The enzyme combination of 66% xylanase and 33% FAE (on a protein loading basis) produced the highest amounts of reducing sugars and FA. The enzyme combination of XT6 (GH10 xylanase) and FAE5 or FAE6 liberated the highest amount of FA while a combination of Xyn11 (GH11 xylanase) and FAE5 or FAE6 produced the highest reducing sugar content. The synergistic interactions which were established between the xylanases and FAEs were further investigated using agricultural residues (corn cobs, rice straw and sugarcane bagasse). The three substrates were subjected to hydrothermal and dilute acid pre-treatment prior to synergy studies. It is generally known that, during pre-treatment, many compounds can be produced which may influence enzymatic hydrolysis. The effects of these by-products were assessed and it was found that lignin and its degradation products were the most inhibitory to the FAEs. The optimised enzyme cocktail was then applied to 1% (w/v) of untreated and pre-treated substrates for the efficient production of XOS and hydroxycinnamic acids. A significant improvement in xylanase substrate degradation was observed, especially with the combination of 66% Xyn11 and 33% FAE6 which displayed an improvement in reducing sugars of approximately 1.9-fold and 3.4-fold for hydrothermal and acid pre-treated corn cobs (compared to when Xyn11 was used alone), respectively. The study demonstrated that pre-treatment substantially enhanced the enzymatic hydrolysis of corn cobs and rice straw. Analysis of the hydrolysate product profiles revealed that the optimised enzyme cocktail displayed great potential for releasing XOS with a low degree of polymerisation. In conclusion, this study provided significant insights into the mechanism of synergistic interactions between xylanases and metagenome-derived FAEs during the hydrolysis of various substrates. The study also demonstrated that optimised enzyme cocktails combined with low severity pre-treatment can facilitate the potential use of xylan-rich lignocellulosic biomass for the production of valuable products in the future. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
An evaluation of the cytotoxic activities of novel artemisinin derivatives: towards targeted therapies for triple-negative breast cancers (TNBC)
- Authors: Kajewole, Deborah Ifeoluwa
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/163329 , vital:41029 , doi:10.21504/10962/163329
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020.
- Full Text:
- Date Issued: 2020
- Authors: Kajewole, Deborah Ifeoluwa
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/163329 , vital:41029 , doi:10.21504/10962/163329
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020.
- Full Text:
- Date Issued: 2020
Application of In Vitro Release Testing (IVRT) and a dermatopharmacokinetic approach (tape stripping) for the assessment of Metronidazole topical formulations
- Rath, Seeprarani Prabirkumar
- Authors: Rath, Seeprarani Prabirkumar
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164617 , vital:41148 , doi:10.21504/10962/164617
- Description: Thesis (PhD)--Rhodes University, Faculty of Pharmacy, Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020
- Authors: Rath, Seeprarani Prabirkumar
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164617 , vital:41148 , doi:10.21504/10962/164617
- Description: Thesis (PhD)--Rhodes University, Faculty of Pharmacy, Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020
Assessment of the microbial quality of various domestic rainwater harvesting systems and the suitability of a nano based treatment method
- Authors: Malema, Mokaba Shirley
- Date: 2020
- Language: English
- Type: thesis , text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/110218 , vital:33249 , https://dx.doi.org/10.21504/10962/110218
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Chemistry, 2020.
- Full Text: false
- Date Issued: 2020
- Authors: Malema, Mokaba Shirley
- Date: 2020
- Language: English
- Type: thesis , text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/110218 , vital:33249 , https://dx.doi.org/10.21504/10962/110218
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Chemistry, 2020.
- Full Text: false
- Date Issued: 2020
Bioinformatic analysis of Aminoacyl tRNA Synthetases as potential antimalarial drug targets
- Authors: Nyamai, Dorothy Wavinya
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164579 , vital:41142 , doi:10.21504/10962/164579
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020
- Full Text:
- Date Issued: 2020
- Authors: Nyamai, Dorothy Wavinya
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164579 , vital:41142 , doi:10.21504/10962/164579
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020
- Full Text:
- Date Issued: 2020
BODIPY dyes for use in nonlinear optics and optical sensing
- Authors: Kubheka, Gugu Patience
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/163352 , vital:41032 , doi:10.21504/10962/163352
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Department of Chemistry, 2020.
- Full Text:
- Date Issued: 2020
- Authors: Kubheka, Gugu Patience
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/163352 , vital:41032 , doi:10.21504/10962/163352
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Department of Chemistry, 2020.
- Full Text:
- Date Issued: 2020
CO2-induced woody thickening depends strongly on interacting abiotic and biotic factors
- Authors: Raubenheimer, Sarah Lynn
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164646 , vital:41151 , doi:10.21504/10962/164646
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Botany, 2020
- Full Text:
- Date Issued: 2020
- Authors: Raubenheimer, Sarah Lynn
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164646 , vital:41151 , doi:10.21504/10962/164646
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Botany, 2020
- Full Text:
- Date Issued: 2020
Comparative analysis of the known Hop1b and the novel Hop1a isoforms of the Hop gene
- Authors: Makhubu, Portia
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164311 , vital:41108 , doi:10.21504/10962/164311
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020
- Full Text:
- Date Issued: 2020
- Authors: Makhubu, Portia
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164311 , vital:41108 , doi:10.21504/10962/164311
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020
- Full Text:
- Date Issued: 2020
Conceptualisations and pedagogical practices of academic literacy in Namibian higher education
- Authors: Julius, Lukas Homateni
- Date: 2021-04
- Subjects: Information literacy -- Study and teaching (Higher) -- Namibia , Academic writing -- Study and teaching -- Namibia , Qualitative research -- Methodology , Academic language -- Namibia , Information literacy -- Social aspects
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177293 , vital:42807 , 10.21504/10962/177293
- Description: The purpose of this study was to investigate academic literacy development lecturers’ conceptualisations of academic literacy and resultant pedagogical practices in academic development courses at three different Higher Education Institutional types in Namibia. The research sites were a Traditional University, a University of Technology and a Comprehensive University. The focus was to understand the extent to which the academics’ conceptions of academic literacy and the resultant pedagogical practices in the academic development courses at these three Higher Education Institutions (HEIs) facilitate epistemological access into students’ chosen fields of study. Bernstein’s Pedagogical theory (1990), Genre theory (1996) and Halliday’s Systemic Functional Linguistics (1978) were used as the study’s theoretical lenses and analytical framework. An interpretative paradigm and a qualitative case study design were employed as the research approach. Semi-structured interviews, classroom observations and documentary evidence were used to generate data. Research findings revealed a common (mis)conception of the nature of academic literacy, the resultant inadequate learning support offered to students in the selected academic literacy development courses, and a clear divorcing of academic literacy interventions from the students’ ‘home’ or mainstream disciplines at the three HEIs. The participants understood academic literacy from an autonomous position as a set of generic skills which could be taught outside of mainstream classes. Moreover, findings revealed that this understanding impacted on the design and assessments of all the academic literacy courses across the three universities under study. The study calls for a context sensitive model through which academic literacy acquisition can be scaffolded to meet the discipline-specific epistemological needs of the students. , Elalakano lyehokololoningomwa lyomapekapeko ndika olyo okukonakona ehumithokomeho lyomikalo dhokulesha nokushanga meilongngo lyopombada (oAcademic Literaci) maaputudhilongi, okukonakona omafatululo giisimanintsa moAcademic Literaci osho wo okutala iizemo yomikalo dhayooloka dhokulonga noku ilonga iilongwa yayooloka miiputudhilo yelongo lyopombada moNamibia. Omapekapeko ngaka oga li ga ningilwa miiputudhilo yomaukwatya ta ga landula; Oshiputudhiilo shopamudhigululwakalo, Oshiputudhilo shopaunongononi, nOshiputudilo shomailongo gaandjakana. Oshintsa shopokati shomapekapeko ngaka osho okuuva ko ondodo yowino osho wo euveko lyoAcademic Literaci maaputudhilongi nonkene euveko nontseyo ndjika tayi longithwa oku eta oshizemo tashi humitha komeho euveko lyopombanda lyaalongwa yomailongo geewino dhayooloka miiputudhilo itatu yelongo lyopombanda; shino otashi kwathele aalongwa yamone ontseyo ndjoka tayi ya kwathele meilongo lyawo. Omapekapeko ngano oga longitha omadhiladhiloukithi (eetheori) ga Bernstein’s Pedagogical theori (1990), Genre theori (1996) na Halliday’s Systemic Functional Linguistics theori (1978), mokufatulula nokundjandjukununa iizemo yomapekapeko. Omodela yokukonakona iizemo yongushu tayi ziilile maakonakonwa, oya tala ekonakono ndika onga oshintsa shopokati, oyo ya longithwa, opo ku monike uuyelele wothaathaa. Omikalo dha longifwa mokukonakona noku gongela uuyelele momapekapeko ngano ongaashi, eenkundathana dhayaali, omatalelo geetundi oshoyo omakonakono giinyanyangidhwa tayi kwandjangele nepekapeko ndika. Iizedjemo yepekapeko ndika otayi ulike kutya opena engwangwano montseyo nenge mefatululo lyuukwatya woAcademic Literaci, shoka sha eta enkundipalo meyambidhidho hali pewa aalongwa miilongwa yeewino dhayooloka. Shika otashi ulike kutya kapena etsokumwe pokati keenkambadhala tadhi ningwa kaapudhilongi dhokulonga oAcademic Litraci miilongwa ya yooloka mbyoka tayi ilongelwa kaalongwa miiputudhilo itatu yopombada. iizemmo yepekapeko olyo tuu mdika oya ulike wo kutya aalongwa mboka yaza komailongo ga yooloka oha yi ilongo nuudhigu opo ya pondole ondondo yomadhiladhilo gopombanda meilongo lyuukumwe. Mokukonakona euveko lyoAcademic Literaci, epekapeko ndika olya ndhindhilike kutya aakuthimbinga oyena euveko lyankundipala lyoterma ‘Academic Literaci,’ ano ya nyengwa okukwatakanitha oohedi dhopetameko ndhoka dhina oku ilongwa meikalekelo - ano pondje yiilongwa ikwao. Oshikwao, iizemo oya ulike kutya euveko ndika otali nwetha mo etungepo lyoAcademic Literaci onga oshilongwa, osho wo omakonakono gasho miiputudilo yombombanda itatu yakwatelwa momapekapeko. Hugunina, epekapeko ndika otali ulike/gandja oshiholelwa shomodela ndjoka oAcademic literacy tai vulu okulongwa opo yi kwatelemo eilongo lyiikwatelela kiilongwa osho yo komaitaalo nokeempumbwe dhaalongwa miiputudhilo yopombabda. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning (CHERTL), 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Julius, Lukas Homateni
- Date: 2021-04
- Subjects: Information literacy -- Study and teaching (Higher) -- Namibia , Academic writing -- Study and teaching -- Namibia , Qualitative research -- Methodology , Academic language -- Namibia , Information literacy -- Social aspects
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177293 , vital:42807 , 10.21504/10962/177293
- Description: The purpose of this study was to investigate academic literacy development lecturers’ conceptualisations of academic literacy and resultant pedagogical practices in academic development courses at three different Higher Education Institutional types in Namibia. The research sites were a Traditional University, a University of Technology and a Comprehensive University. The focus was to understand the extent to which the academics’ conceptions of academic literacy and the resultant pedagogical practices in the academic development courses at these three Higher Education Institutions (HEIs) facilitate epistemological access into students’ chosen fields of study. Bernstein’s Pedagogical theory (1990), Genre theory (1996) and Halliday’s Systemic Functional Linguistics (1978) were used as the study’s theoretical lenses and analytical framework. An interpretative paradigm and a qualitative case study design were employed as the research approach. Semi-structured interviews, classroom observations and documentary evidence were used to generate data. Research findings revealed a common (mis)conception of the nature of academic literacy, the resultant inadequate learning support offered to students in the selected academic literacy development courses, and a clear divorcing of academic literacy interventions from the students’ ‘home’ or mainstream disciplines at the three HEIs. The participants understood academic literacy from an autonomous position as a set of generic skills which could be taught outside of mainstream classes. Moreover, findings revealed that this understanding impacted on the design and assessments of all the academic literacy courses across the three universities under study. The study calls for a context sensitive model through which academic literacy acquisition can be scaffolded to meet the discipline-specific epistemological needs of the students. , Elalakano lyehokololoningomwa lyomapekapeko ndika olyo okukonakona ehumithokomeho lyomikalo dhokulesha nokushanga meilongngo lyopombada (oAcademic Literaci) maaputudhilongi, okukonakona omafatululo giisimanintsa moAcademic Literaci osho wo okutala iizemo yomikalo dhayooloka dhokulonga noku ilonga iilongwa yayooloka miiputudhilo yelongo lyopombada moNamibia. Omapekapeko ngaka oga li ga ningilwa miiputudhilo yomaukwatya ta ga landula; Oshiputudhiilo shopamudhigululwakalo, Oshiputudhilo shopaunongononi, nOshiputudilo shomailongo gaandjakana. Oshintsa shopokati shomapekapeko ngaka osho okuuva ko ondodo yowino osho wo euveko lyoAcademic Literaci maaputudhilongi nonkene euveko nontseyo ndjika tayi longithwa oku eta oshizemo tashi humitha komeho euveko lyopombanda lyaalongwa yomailongo geewino dhayooloka miiputudhilo itatu yelongo lyopombanda; shino otashi kwathele aalongwa yamone ontseyo ndjoka tayi ya kwathele meilongo lyawo. Omapekapeko ngano oga longitha omadhiladhiloukithi (eetheori) ga Bernstein’s Pedagogical theori (1990), Genre theori (1996) na Halliday’s Systemic Functional Linguistics theori (1978), mokufatulula nokundjandjukununa iizemo yomapekapeko. Omodela yokukonakona iizemo yongushu tayi ziilile maakonakonwa, oya tala ekonakono ndika onga oshintsa shopokati, oyo ya longithwa, opo ku monike uuyelele wothaathaa. Omikalo dha longifwa mokukonakona noku gongela uuyelele momapekapeko ngano ongaashi, eenkundathana dhayaali, omatalelo geetundi oshoyo omakonakono giinyanyangidhwa tayi kwandjangele nepekapeko ndika. Iizedjemo yepekapeko ndika otayi ulike kutya opena engwangwano montseyo nenge mefatululo lyuukwatya woAcademic Literaci, shoka sha eta enkundipalo meyambidhidho hali pewa aalongwa miilongwa yeewino dhayooloka. Shika otashi ulike kutya kapena etsokumwe pokati keenkambadhala tadhi ningwa kaapudhilongi dhokulonga oAcademic Litraci miilongwa ya yooloka mbyoka tayi ilongelwa kaalongwa miiputudhilo itatu yopombada. iizemmo yepekapeko olyo tuu mdika oya ulike wo kutya aalongwa mboka yaza komailongo ga yooloka oha yi ilongo nuudhigu opo ya pondole ondondo yomadhiladhilo gopombanda meilongo lyuukumwe. Mokukonakona euveko lyoAcademic Literaci, epekapeko ndika olya ndhindhilike kutya aakuthimbinga oyena euveko lyankundipala lyoterma ‘Academic Literaci,’ ano ya nyengwa okukwatakanitha oohedi dhopetameko ndhoka dhina oku ilongwa meikalekelo - ano pondje yiilongwa ikwao. Oshikwao, iizemo oya ulike kutya euveko ndika otali nwetha mo etungepo lyoAcademic Literaci onga oshilongwa, osho wo omakonakono gasho miiputudilo yombombanda itatu yakwatelwa momapekapeko. Hugunina, epekapeko ndika otali ulike/gandja oshiholelwa shomodela ndjoka oAcademic literacy tai vulu okulongwa opo yi kwatelemo eilongo lyiikwatelela kiilongwa osho yo komaitaalo nokeempumbwe dhaalongwa miiputudhilo yopombabda. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning (CHERTL), 2021
- Full Text:
- Date Issued: 2021-04
Constraining simulation uncertainties in a hydrological model of the Congo River Basin including a combined modelling approach for channel-wetland exchanges
- Authors: Kabuya, Pierre Mulamba
- Date: 2021-04
- Subjects: Congo River Watershed , Watersheds -- Congo (Democratic Republic) , Hydrologic models , Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Wetland hydrology
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177997 , vital:42897 , 10.21504/10962/177997
- Description: Compared to other large river basins of the world, such as the Amazon, the Congo River Basin appears to be the most ungauged and less studied. This is partly because the basin lacks sufficient observational hydro-climatic monitoring stations and appropriate information on physiographic basin properties at a spatial scale deemed for hydrological applications, making it difficult to estimate water resources at the scale of sub-basins (Chapter 3). In the same time, the basin is facing the challenges related to rapid population growth, uncontrolled urbanisation as well as climate change. Adequate quantification of hydrological processes across different spatial and temporal scales in the basin, and the drivers of change, is essential for prediction and strategic planning to ensure sustainable management of water resources in the Congo River Basin. Hydrological models are particularly important to generate the required information. However, the shortness of the available streamflow records, lack of spatial representativeness of the available streamflow gauging stations and the lack of understanding of the processes in channel-wetland exchanges, are the main challenges that constrain the use of traditional approaches to models development. They also contribute to increased uncertainty in the estimation of water resources across the basin (Chapter 1 and 2). Given this ungauged nature of the Congo River Basin, it is important to resort to hydrological modelling approaches that can reasonably quantify and model the uncertainty associated with water resources estimation (Chapter 4) to make hydrological predictions reliable. This study explores appropriate methods for hydrological predictions and water resources assessment in ungauged catchments of the Congo River Basin. In this context, the core modelling framework combines the quantification of uncertainty in constraint indices, hydrological modelling and hydrodynamic modelling. The latter accounts for channel-wetland exchanges in sub-basins where wetlands exert considerable influence on downstream flow regimes at the monthly time scale. The constraint indices are the characteristics of a sub-basin’s long-term hydrological behaviour and may reflect the dynamics of the different components of the catchment water balance such as climate, water storage and different runoff processes. Currently, six constraint indices namely the mean monthly runoff volume (MMQ in m3 *106), mean monthly groundwater recharge depth (MMR in mm), the 10th, 50th and 90th percentiles of the flow duration curve expressed as a fraction of MMQ (Q10/MMQ, Q50/MMQ, Q90/MMQ) and the percentage of time that zero flows are expected (%Zero), are used in the modelling approach. These were judged to be the minimum number of key indices that can discriminate between different hydrological responses. The constraint indices in the framework help to determine an uncertainty range within which behavioural model parameters of the expected hydrological response can be identified. Predictive equations of the constraint indices across all climate and physiographic regions of the Congo Basin were based only on the aridity index because it was the most influential sub-basin attribute (Chapter 5) for which quantitative information was available. The degree of uncertainty in the constraint Q10/MMQ and Q50/MMQ indices is less than 41%, while it is somewhat higher for the mean monthly runoff (MMQ) and Q90/MMQ constraint indices. The established uncertainty ranges of the constraint indices were tested in some selected sub-basins of the Congo Basin, including the Lualaba (93 sub-basins), Sangha (24 sub-basins), Oubangui (19 sub-basins), Batéké plateaux (4 sub-basins), Kasai (4 sub-basins) and Inkisi (3 sub-basins). The results proved useful through the application of a 2-stage uncertainty approach of the PITMAN model. However, it comes out of this study that the application of the original constraint indices ranges (Chapter 5) generated satisfactory simulation results in some areas, while in others both small and large adjustments were required to fully capture some aspects of the observed hydrological responses (Chapter 6). Part of the reason is attributed to the availability and quality of streamflow data used to develop the constraint indices ranges (Chapter 5). The main issue identified in the modelling process was whether the changes made to the original constraints at headwater-gauged sub-basins can be applied to ungauged upstream sub-basins to match the observed flow at downstream gauging stations. Ideally, only gauged sub-basin’s constraints can be easily revised based on the observed flow. However, the refinement made to gauged sub-basins alone may fail to substantially affect the results if ungauged upstream sub-basins exert a major impact on defining downstream hydrological response. The majority of gauging stations used in this analysis are located downstream of many upstream ungauged sub-basins and therefore adjustments were required in ungauged sub-basins. These adjustments consist of shifting the full range of a constraint index either towards higher or lower values, depending on the degree to which the simulated uncertainty bounds depart from the observed flow. While this modelling approach seems effective in capturing many aspects of the hydrological responses with a reduced level of uncertainty compared to a previous study, it is recommended that the approach be extended to the remaining parts of the Congo Basin and assessed under current and future development conditions including environmental changes. A 2D hydrodynamic river-wetland model (LISFLOOD-FP) has been used to explicitly represent the inundation process exchanges between river channels and wetland systems. The hydrodynamic modelling outputs are used to calibrate the PITMAN wetland sub-model parameters. The five hydrodynamic models constructed for Ankoro, Kamalondo, Kundelungu, Mweru and Tshiangalele wetland systems have been partially validated using independent estimates of inundation extents available from Landsat imagery. Other sources of data such as remote sensing of water level altimetry, SAR images and wetland storage estimates may be used to improve the validation results. However, the important objective in this study was to make sure that flow volume exchanges between river channels and their adjacent floodplains were being simulated realistically. The wetland sub-model parameters are calibrated in a spreadsheet version of the PITMAN wetland routine to achieve visual correspondence between the LISFLOOD-FP and PITMAN wetland sub-model outputs (Storage volumes and channel outputs). The hysteretic patterns of the river-wetland processes were quantified using hysteresis indices and were associated with the spill and return flow parameters of the wetland sub-model and eventually with the wetland morphometric characteristics. One example is the scale parameter of the return flow function (AA), which shows a good relationship with the average surface slope of the wetland when the coefficient parameter (BB) of the same function is kept constant to a value of 1.25. The same parameter (AA) is a good indicator of the wetland emptying mechanism. A small AA indicates a wetland that slowly releases its flow, resulting in a highly delayed and attenuated hydrological response in downstream sub-basins. This understanding has a practical advantage for the estimation of the PITMAN wetland parameters in the many areas where it is not possible, or where the resources are not available, to run complex hydrodynamic models (Chapter 7). The inclusion of these LISFLOOD-FP informed wetland parameters in the basin-scale hydrological modelling results in acceptable simulations for the lower Lualaba drainage system. The small wetlands, like Ankoro and Tshiangalele, have a negligible impact on downstream flow regimes, whereas large wetlands, such as Kamalondo and Mweru, have very large impacts. In general, the testing of the original constraint indices in the region of wetlands and further downstream of the Lualaba drainage system has shown acceptable results. However, there remains an unresolved uncertainty issue related to the under and over-estimation of some aspects of the hydrological response at both Mulongo and Ankoro, two gauging stations in the immediate downstream of the Kamalondo wetland system. It is difficult to attribute this uncertainty to Kamalondo wetland parameters alone because many of the incremental sub-basins contributing to wetland inflows are ungauged. The issue at Mulongo is the under simulation of low flow, while the high flows at the Ankoro gauging station are over-simulated. However, the pattern of the calibrated constraint indices in this region (Chapter 8) shows that the under simulation of low flow at Mulongo cannot be attributed to incremental sub-basins (between Bukama, Kapolowe and Mulongo gauging stations), because their Q90/MMQ constraint indices are even slightly above the original constraint ranges, but maintain a spatial consistency with sub-basins of other regions. Similarly, sub-basins located between Mulongo, Luvua and Ankoro gauging stations have high flow indices slightly below the original constraint ranges and therefore they are unlikely to be responsible for the over simulation of high flow at the Ankoro gauging station. These facts highlight the need for a further understanding of the complex wetland system of Kamalondo. Short-term data collection and monitoring programme are required. Important tributaries that drain to this wetland need to be monitored by installing water level loggers and periodically collecting flow data and river bathymetry. This programme should lead to the development of rating curves of wetland input tributaries. This would partially solve the unresolved uncertainty issues at the Ankoro and Mulongo gauging stations. The integrated modelling approach offers many opportunities in the Congo Basin. The quantified and modelled uncertainty helps to identify regions with high uncertainty and allows for the identification of various data collection and management strategies that can potentially contribute to the uncertainty reduction. The quantified channel-wetland exchanges contribute to the improvement of the overall knowledge of water resources estimation within the regions where the effects of wetlands are evident even at the monthly time scale. In contrast, ignoring uncertainty in the estimates of water resources availability means that water resources planning and management decisions in the Congo Basin will continue to be based on inadequate information and unquantified uncertainty, thus increasing the risk associated with water resources decision making. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Kabuya, Pierre Mulamba
- Date: 2021-04
- Subjects: Congo River Watershed , Watersheds -- Congo (Democratic Republic) , Hydrologic models , Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Wetland hydrology
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177997 , vital:42897 , 10.21504/10962/177997
- Description: Compared to other large river basins of the world, such as the Amazon, the Congo River Basin appears to be the most ungauged and less studied. This is partly because the basin lacks sufficient observational hydro-climatic monitoring stations and appropriate information on physiographic basin properties at a spatial scale deemed for hydrological applications, making it difficult to estimate water resources at the scale of sub-basins (Chapter 3). In the same time, the basin is facing the challenges related to rapid population growth, uncontrolled urbanisation as well as climate change. Adequate quantification of hydrological processes across different spatial and temporal scales in the basin, and the drivers of change, is essential for prediction and strategic planning to ensure sustainable management of water resources in the Congo River Basin. Hydrological models are particularly important to generate the required information. However, the shortness of the available streamflow records, lack of spatial representativeness of the available streamflow gauging stations and the lack of understanding of the processes in channel-wetland exchanges, are the main challenges that constrain the use of traditional approaches to models development. They also contribute to increased uncertainty in the estimation of water resources across the basin (Chapter 1 and 2). Given this ungauged nature of the Congo River Basin, it is important to resort to hydrological modelling approaches that can reasonably quantify and model the uncertainty associated with water resources estimation (Chapter 4) to make hydrological predictions reliable. This study explores appropriate methods for hydrological predictions and water resources assessment in ungauged catchments of the Congo River Basin. In this context, the core modelling framework combines the quantification of uncertainty in constraint indices, hydrological modelling and hydrodynamic modelling. The latter accounts for channel-wetland exchanges in sub-basins where wetlands exert considerable influence on downstream flow regimes at the monthly time scale. The constraint indices are the characteristics of a sub-basin’s long-term hydrological behaviour and may reflect the dynamics of the different components of the catchment water balance such as climate, water storage and different runoff processes. Currently, six constraint indices namely the mean monthly runoff volume (MMQ in m3 *106), mean monthly groundwater recharge depth (MMR in mm), the 10th, 50th and 90th percentiles of the flow duration curve expressed as a fraction of MMQ (Q10/MMQ, Q50/MMQ, Q90/MMQ) and the percentage of time that zero flows are expected (%Zero), are used in the modelling approach. These were judged to be the minimum number of key indices that can discriminate between different hydrological responses. The constraint indices in the framework help to determine an uncertainty range within which behavioural model parameters of the expected hydrological response can be identified. Predictive equations of the constraint indices across all climate and physiographic regions of the Congo Basin were based only on the aridity index because it was the most influential sub-basin attribute (Chapter 5) for which quantitative information was available. The degree of uncertainty in the constraint Q10/MMQ and Q50/MMQ indices is less than 41%, while it is somewhat higher for the mean monthly runoff (MMQ) and Q90/MMQ constraint indices. The established uncertainty ranges of the constraint indices were tested in some selected sub-basins of the Congo Basin, including the Lualaba (93 sub-basins), Sangha (24 sub-basins), Oubangui (19 sub-basins), Batéké plateaux (4 sub-basins), Kasai (4 sub-basins) and Inkisi (3 sub-basins). The results proved useful through the application of a 2-stage uncertainty approach of the PITMAN model. However, it comes out of this study that the application of the original constraint indices ranges (Chapter 5) generated satisfactory simulation results in some areas, while in others both small and large adjustments were required to fully capture some aspects of the observed hydrological responses (Chapter 6). Part of the reason is attributed to the availability and quality of streamflow data used to develop the constraint indices ranges (Chapter 5). The main issue identified in the modelling process was whether the changes made to the original constraints at headwater-gauged sub-basins can be applied to ungauged upstream sub-basins to match the observed flow at downstream gauging stations. Ideally, only gauged sub-basin’s constraints can be easily revised based on the observed flow. However, the refinement made to gauged sub-basins alone may fail to substantially affect the results if ungauged upstream sub-basins exert a major impact on defining downstream hydrological response. The majority of gauging stations used in this analysis are located downstream of many upstream ungauged sub-basins and therefore adjustments were required in ungauged sub-basins. These adjustments consist of shifting the full range of a constraint index either towards higher or lower values, depending on the degree to which the simulated uncertainty bounds depart from the observed flow. While this modelling approach seems effective in capturing many aspects of the hydrological responses with a reduced level of uncertainty compared to a previous study, it is recommended that the approach be extended to the remaining parts of the Congo Basin and assessed under current and future development conditions including environmental changes. A 2D hydrodynamic river-wetland model (LISFLOOD-FP) has been used to explicitly represent the inundation process exchanges between river channels and wetland systems. The hydrodynamic modelling outputs are used to calibrate the PITMAN wetland sub-model parameters. The five hydrodynamic models constructed for Ankoro, Kamalondo, Kundelungu, Mweru and Tshiangalele wetland systems have been partially validated using independent estimates of inundation extents available from Landsat imagery. Other sources of data such as remote sensing of water level altimetry, SAR images and wetland storage estimates may be used to improve the validation results. However, the important objective in this study was to make sure that flow volume exchanges between river channels and their adjacent floodplains were being simulated realistically. The wetland sub-model parameters are calibrated in a spreadsheet version of the PITMAN wetland routine to achieve visual correspondence between the LISFLOOD-FP and PITMAN wetland sub-model outputs (Storage volumes and channel outputs). The hysteretic patterns of the river-wetland processes were quantified using hysteresis indices and were associated with the spill and return flow parameters of the wetland sub-model and eventually with the wetland morphometric characteristics. One example is the scale parameter of the return flow function (AA), which shows a good relationship with the average surface slope of the wetland when the coefficient parameter (BB) of the same function is kept constant to a value of 1.25. The same parameter (AA) is a good indicator of the wetland emptying mechanism. A small AA indicates a wetland that slowly releases its flow, resulting in a highly delayed and attenuated hydrological response in downstream sub-basins. This understanding has a practical advantage for the estimation of the PITMAN wetland parameters in the many areas where it is not possible, or where the resources are not available, to run complex hydrodynamic models (Chapter 7). The inclusion of these LISFLOOD-FP informed wetland parameters in the basin-scale hydrological modelling results in acceptable simulations for the lower Lualaba drainage system. The small wetlands, like Ankoro and Tshiangalele, have a negligible impact on downstream flow regimes, whereas large wetlands, such as Kamalondo and Mweru, have very large impacts. In general, the testing of the original constraint indices in the region of wetlands and further downstream of the Lualaba drainage system has shown acceptable results. However, there remains an unresolved uncertainty issue related to the under and over-estimation of some aspects of the hydrological response at both Mulongo and Ankoro, two gauging stations in the immediate downstream of the Kamalondo wetland system. It is difficult to attribute this uncertainty to Kamalondo wetland parameters alone because many of the incremental sub-basins contributing to wetland inflows are ungauged. The issue at Mulongo is the under simulation of low flow, while the high flows at the Ankoro gauging station are over-simulated. However, the pattern of the calibrated constraint indices in this region (Chapter 8) shows that the under simulation of low flow at Mulongo cannot be attributed to incremental sub-basins (between Bukama, Kapolowe and Mulongo gauging stations), because their Q90/MMQ constraint indices are even slightly above the original constraint ranges, but maintain a spatial consistency with sub-basins of other regions. Similarly, sub-basins located between Mulongo, Luvua and Ankoro gauging stations have high flow indices slightly below the original constraint ranges and therefore they are unlikely to be responsible for the over simulation of high flow at the Ankoro gauging station. These facts highlight the need for a further understanding of the complex wetland system of Kamalondo. Short-term data collection and monitoring programme are required. Important tributaries that drain to this wetland need to be monitored by installing water level loggers and periodically collecting flow data and river bathymetry. This programme should lead to the development of rating curves of wetland input tributaries. This would partially solve the unresolved uncertainty issues at the Ankoro and Mulongo gauging stations. The integrated modelling approach offers many opportunities in the Congo Basin. The quantified and modelled uncertainty helps to identify regions with high uncertainty and allows for the identification of various data collection and management strategies that can potentially contribute to the uncertainty reduction. The quantified channel-wetland exchanges contribute to the improvement of the overall knowledge of water resources estimation within the regions where the effects of wetlands are evident even at the monthly time scale. In contrast, ignoring uncertainty in the estimates of water resources availability means that water resources planning and management decisions in the Congo Basin will continue to be based on inadequate information and unquantified uncertainty, thus increasing the risk associated with water resources decision making. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2021
- Full Text:
- Date Issued: 2021-04
Design of Immunobiosensors for Detection of Tumor-Associated Anti-P53 Autoantibodies: Method Development
- Authors: Adeniyi, Omotayo Kayode
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/162988 , vital:41002 , 10.21504/10962/162988
- Description: Introduction -- Experimental -- Label-Free Impedimetric Sensing of Anti-P53ab... -- Fluorescent detection of Anti-P53ab -- Peroxidase-like activity of Fe3O4@SiNP-APTES-Au@Pd... -- Colorimetric detection of Anti-P53ab , Thesis (PhD)--Rhodes University, Science Faculty, Department of Chemistry, 2020. , Detection and profiling of circulating tumor-associated autoantibodies (TAAbs) are useful for screening and early-stage diagnosis of asymptomatic lung cancer. Immunobiosensor technologies aimed to accomplish the highly sensitive, rapid and low-cost detection of TAAbs can improve the early-stage detection of lung cancer. Immunobiosensors for the detection of anti-P53-tumour associated autoantibodies have been developed in this work. The design of sensing interfaces with immobilized P53 protein (P53ag) as a sensing element layer on a solid interface was investigated. Several methods of detecting anti-P53-antibodies (anti-P53ab) were investigated. These methods are label-free detection using electrochemical impedance spectroscopy (EIS) and two label techniques. The label-free electrochemical techniques utilize gold electrode pre-modified with a conducting layer of electrochemically grafted phenylethylamine for covalent immobilization of P53ag. The limit of anti-P53ab detection with the label-free EIS was 103.0 pg.ml-1. The labeled technique developed utilizes fluorescent, and peroxidase-like nanomaterial labeled antibody as a detection probe. For the fluorescence detection, fluorescent silica nanoparticles were synthesized by overloading FITC into the silica matrix and conjugated to detection antibody (anti-IgG). The detection of the anti-P53ab was based on the dissolution of the silica nanoparticles to release the loaded dye as a signal amplification strategy. The fluorescence detection was carried out on a microplate, and magnetic bead modified P53-antigen platforms and limit of detection (LoD) were 42.0 fg.ml-1 and 3.3 fg.ml-1 for anti-P53ab; respectively. Fe3O4@SiNP-APTES-Au@Pd hybrid nanoparticles were synthesized, and their peroxidase-like activity and colorimetric detection were evaluated. The Fe3O4@SiNP-APTES-Au@Pd exhibited comparable activity to HRP. The Fe3O4@SiNP-APTES-Au@Pd was conjugated to protein-G-anti-IgG for the detection of anti-P53ab on a microplate and cellulose paper platforms. The LoD was 20.0 fg.ml-1 and 63.0 fg.ml-1 for the microplate and cellulose paper platform; respectively. The potential application of the designed immunobiosensor was evaluated in simulated serum samples. The developed sensors showed higher detection sensitivity, stability and had a lower detection limit for anti-P53ab when compared with the ELISA based detection. The results have provided alternative and effective quantification approaches to ELISA and a promising future for multiplexed detection of tumor-associated autoantibodies. The developed methodologies in this thesis could be applied for the detection of other autoantibodies in other cancer types and auto-immune diseases.
- Full Text:
- Date Issued: 2020
- Authors: Adeniyi, Omotayo Kayode
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/162988 , vital:41002 , 10.21504/10962/162988
- Description: Introduction -- Experimental -- Label-Free Impedimetric Sensing of Anti-P53ab... -- Fluorescent detection of Anti-P53ab -- Peroxidase-like activity of Fe3O4@SiNP-APTES-Au@Pd... -- Colorimetric detection of Anti-P53ab , Thesis (PhD)--Rhodes University, Science Faculty, Department of Chemistry, 2020. , Detection and profiling of circulating tumor-associated autoantibodies (TAAbs) are useful for screening and early-stage diagnosis of asymptomatic lung cancer. Immunobiosensor technologies aimed to accomplish the highly sensitive, rapid and low-cost detection of TAAbs can improve the early-stage detection of lung cancer. Immunobiosensors for the detection of anti-P53-tumour associated autoantibodies have been developed in this work. The design of sensing interfaces with immobilized P53 protein (P53ag) as a sensing element layer on a solid interface was investigated. Several methods of detecting anti-P53-antibodies (anti-P53ab) were investigated. These methods are label-free detection using electrochemical impedance spectroscopy (EIS) and two label techniques. The label-free electrochemical techniques utilize gold electrode pre-modified with a conducting layer of electrochemically grafted phenylethylamine for covalent immobilization of P53ag. The limit of anti-P53ab detection with the label-free EIS was 103.0 pg.ml-1. The labeled technique developed utilizes fluorescent, and peroxidase-like nanomaterial labeled antibody as a detection probe. For the fluorescence detection, fluorescent silica nanoparticles were synthesized by overloading FITC into the silica matrix and conjugated to detection antibody (anti-IgG). The detection of the anti-P53ab was based on the dissolution of the silica nanoparticles to release the loaded dye as a signal amplification strategy. The fluorescence detection was carried out on a microplate, and magnetic bead modified P53-antigen platforms and limit of detection (LoD) were 42.0 fg.ml-1 and 3.3 fg.ml-1 for anti-P53ab; respectively. Fe3O4@SiNP-APTES-Au@Pd hybrid nanoparticles were synthesized, and their peroxidase-like activity and colorimetric detection were evaluated. The Fe3O4@SiNP-APTES-Au@Pd exhibited comparable activity to HRP. The Fe3O4@SiNP-APTES-Au@Pd was conjugated to protein-G-anti-IgG for the detection of anti-P53ab on a microplate and cellulose paper platforms. The LoD was 20.0 fg.ml-1 and 63.0 fg.ml-1 for the microplate and cellulose paper platform; respectively. The potential application of the designed immunobiosensor was evaluated in simulated serum samples. The developed sensors showed higher detection sensitivity, stability and had a lower detection limit for anti-P53ab when compared with the ELISA based detection. The results have provided alternative and effective quantification approaches to ELISA and a promising future for multiplexed detection of tumor-associated autoantibodies. The developed methodologies in this thesis could be applied for the detection of other autoantibodies in other cancer types and auto-immune diseases.
- Full Text:
- Date Issued: 2020