Cultural clusters as a local economic development strategy in rural, small town areas: the Sarah Baartman District in the Eastern Cape of South Africa
- Authors: Drummond, Fiona Jane
- Date: 2019
- Subjects: Cultural industries -- South Africa -- Eastern Cape , Creative ability -- Economic aspects -- South Africa -- Eastern Cape , Arts -- Economic aspects -- South Africa -- Eastern Cape , Culture -- Economic aspects -- South Africa -- Eastern Cape , Economic development -- South Africa -- Eastern Cape , Economic development projects -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/71568 , vital:29879
- Description: It is increasingly recognized that the cultural and creative industries (CCIs) can play an important role in economic growth and development. Governments around the world, including South Africa, are implementing culture‐led economic growth and development strategies on national and regional scales. CCIs tend to cluster around large cities because of existing hard and soft infrastructure such as networking advantages and access to skilled labour, however, much less is known about the potential of the CCIs to drive rural development. This thesis thus investigates the potential of the CCIs to cluster in small towns and rural areas. Moreover, it examines the relationship between the CCIs and socio‐economic development. The CCIs have been touted as a catalyst for economic growth and development and so have often been used in urban regeneration schemes. The Sarah Baartman District (SBD) of South Africa’s Eastern Cape has identified culture as a potential new economic driver. Establishing a new development path is necessary as the former economic mainstay, agriculture, has declined in the region, creating poverty and unemployment problems. However, the SBD has only small towns which, according to the literature, are not suited to CCI clustering. Despite this, there is evidence of cultural clustering in some of the SBD’s small towns like Nieu Bethesda and Bathurst. This research therefore conducted an audit of the CCIs in the district and used geographic information systems (GIS) to map their locations by UNESCO Framework of Cultural Statistics (FCS) domains in order to determine the extent to which clustering has occurred in a small town setting. The audit identified 1 048 CCIs operating in the district and determined that clustering is possible within some small towns, depending on their demographic, economic, social, geographic and historic characteristics. For small towns where clusters exist or the potential for cluster formation is present, the domains in which the town holds a comparative advantage, based on domain proportions and location quotients, should be pursued for local economic development (LED). In this case, Visual Arts and Crafts and Cultural Heritage were prominent throughout the district while Design and Creative Services and Performance and Celebration had small regional concentrations. Theory suggests that the presence of CCIs is linked to higher levels of economic development as the creative class is more likely to be attracted to more highly developed areas, usually large cities. Furthermore, spillover effects from cultural activity promotes further development under the virtuous cycle. To investigate the relationship between CCI clusters and socio‐economic development, the locational data of municipal level CCI numbers is overlaid with a regional development indicator, a socio‐economic status index, which is based on census data and includes economic and social components. Results show that there is a general positive trend of CCIs locating in larger numbers (clustering) in areas with higher socio‐economic development performances.
- Full Text:
- Date Issued: 2019
- Authors: Drummond, Fiona Jane
- Date: 2019
- Subjects: Cultural industries -- South Africa -- Eastern Cape , Creative ability -- Economic aspects -- South Africa -- Eastern Cape , Arts -- Economic aspects -- South Africa -- Eastern Cape , Culture -- Economic aspects -- South Africa -- Eastern Cape , Economic development -- South Africa -- Eastern Cape , Economic development projects -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/71568 , vital:29879
- Description: It is increasingly recognized that the cultural and creative industries (CCIs) can play an important role in economic growth and development. Governments around the world, including South Africa, are implementing culture‐led economic growth and development strategies on national and regional scales. CCIs tend to cluster around large cities because of existing hard and soft infrastructure such as networking advantages and access to skilled labour, however, much less is known about the potential of the CCIs to drive rural development. This thesis thus investigates the potential of the CCIs to cluster in small towns and rural areas. Moreover, it examines the relationship between the CCIs and socio‐economic development. The CCIs have been touted as a catalyst for economic growth and development and so have often been used in urban regeneration schemes. The Sarah Baartman District (SBD) of South Africa’s Eastern Cape has identified culture as a potential new economic driver. Establishing a new development path is necessary as the former economic mainstay, agriculture, has declined in the region, creating poverty and unemployment problems. However, the SBD has only small towns which, according to the literature, are not suited to CCI clustering. Despite this, there is evidence of cultural clustering in some of the SBD’s small towns like Nieu Bethesda and Bathurst. This research therefore conducted an audit of the CCIs in the district and used geographic information systems (GIS) to map their locations by UNESCO Framework of Cultural Statistics (FCS) domains in order to determine the extent to which clustering has occurred in a small town setting. The audit identified 1 048 CCIs operating in the district and determined that clustering is possible within some small towns, depending on their demographic, economic, social, geographic and historic characteristics. For small towns where clusters exist or the potential for cluster formation is present, the domains in which the town holds a comparative advantage, based on domain proportions and location quotients, should be pursued for local economic development (LED). In this case, Visual Arts and Crafts and Cultural Heritage were prominent throughout the district while Design and Creative Services and Performance and Celebration had small regional concentrations. Theory suggests that the presence of CCIs is linked to higher levels of economic development as the creative class is more likely to be attracted to more highly developed areas, usually large cities. Furthermore, spillover effects from cultural activity promotes further development under the virtuous cycle. To investigate the relationship between CCI clusters and socio‐economic development, the locational data of municipal level CCI numbers is overlaid with a regional development indicator, a socio‐economic status index, which is based on census data and includes economic and social components. Results show that there is a general positive trend of CCIs locating in larger numbers (clustering) in areas with higher socio‐economic development performances.
- Full Text:
- Date Issued: 2019
Investigating and expanding learning across activity system boundaries in improved cook stove innovation diffusion and adoption in Malawi
- Jalasi, Experencia Madalitso
- Authors: Jalasi, Experencia Madalitso
- Date: 2019
- Subjects: Stoves, Wood -- Technological innovations -- Malawi , Biomass stoves -- Malawi , Economic development projects -- Environmental aspects -- Malawi , Rural development projects -- Environmental aspects -- Malawi
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68170 , vital:29212
- Description: This study investigates and expands learning within and between activity systems working with Improved Cook Stoves (hereafter ICS) in Malawi. The study focuses on how existing learning interactions among ICS actors can be expanded using expansive learning processes, mobilised through Boundary Crossing Change Laboratories (BCCL) to potentially inform more sustained uptake and utilisation of the ICS technology. The ICS, as a socio-technical innovation, seeks to respond to climate change mitigation and adaptation efforts in the country. However, sustained uptake and utilisation has been problematic. The study is located in the field of Environmental Education, with emphasis on the diffusion and adoption of socio-technical innovations in the context of ICS technology. The study addresses societal environmental health risks faced by people using traditional biomass fuels indoors on open fires, commonly referred to as Three Stone Fire (hereafter TSF) through formative intervention supported by Developmental Work Research (hereafter DWR) or Expansive Learning. The study was conducted in three climate change hotspot districts in Malawi: Balaka, Dedza and Mzimba. The case studies are in each of the three administrative regions of the country. Chapita Village case study is in Balaka district, in the Southern region; Waziloya Makwakwa Village is in Mzimba district in the Northern region; and Chilije Village in Dedza district in the Central region. In order to engage the potential for transformation in study areas, I divided the study into two phases. The first phase involved collection of ethnographic data to more deeply understand the context of the problem including existing learning approaches. This informed the second phase, which focused on expansive learning processes in the Chapita and Waziloya Makwakwa case studies. The study used a formative intervention approach, which focused on supporting the actors to manage the challenges they were facing and work out the problematic situations in their joint activity. The study employed a qualitative intensive research design because it aimed at in-depth understanding of uptake and utilisation of ICS. This was an important foundation for improving the existing situations through co-creating solutions with research participants. With this generative and action-oriented approach, the study employed a multiple embedded case study design. CHAT and Critical Realism were the two main theories that I employed as they resonated with the transformative interest of the study through focusing on learning as an emancipatory process with potential for transformation of human practices. In addition, I used the methodological theory of Expansive Learning from CHAT to guide the expansive learning processes. With the critical realist framing of the study, I employed a critical realist analytical framework, and used inductive, abductive and retroductive analyses.The major findings of the study indicate that broadly, uptake and utilisation of ICS is problematic, hence unsustained. The findings indicate that the majority of end-users in Chapita and Chilije case studies switched between TSF and ICS, or abandoned the ICS, which was not the case in Waziloya Makwakwa case study. The underlying causal mechanisms that appear to explain and influence end-users’ actions in all the case studies were the search for convenience during the cooking activity. Further, findings revealed that learning interactions among activity systems were unidirectional which provides evidence for top-down approaches prevalent in cook stove dissemination. The findings also indicated that most of the learning taking place was informative, not transformative. It was also inadequate, particularly for end-users. A causal mechanism that appears to shape how actors are learning ICS technology is poverty, which results in over-reliance on donor-driven projects. Findings also reveal that contradictions in the learning, uptake and utilisation of ICS influence the profile of uptake and utilisation of ICSs. Further, the change-oriented learning processes, as carried out in the Chapita and Waziloya Makwakwa case studies, have shown their potential in expanding learning interactions among ICS actors, evoking and supporting their transformative agency and enhancing their reflexivity. These processes are crucial in development and sustaining learning and change in the uptake and utilisation of ICS innovation. The main contribution of the study is methodological. It contributes broadly to diffusion and adoption of socio-technical innovations through change-oriented expansive learning processes. The study generated an Innovative Extension and Communicative Methodology, which foregrounds interaction and learning and links the socio-technical innovation intention and socio-technical innovation uptake and utilisation that potentially informs the dissemination and implementation of ICS projects. Further, the study contributes to community education by mobilising communities to address contradictions, absences, or ills in the society via change-oriented learning processes. The societal ills facing the case study sites and the areas around them, caused by climate change and variability and deforestation exacerbate the lives of rural women who are afflicted by conditions of poverty. The study contributes to global and local efforts and initiatives to address environmental health risks faced by people using traditional biomass fuels indoors on TSF and climate change mitigation and adaptation. This study has found out that putting the agency of the end-user in the centre in socio-technical transitions through context-based problem resolution and rigorous deliberate1 mediated processes of participation and learning, which allows multivoicedness and takes power relations into account, catalyses transformative agency, reflexivity, collaboration and learning capacity of ICS actors for sustained uptake and utilisation of the ICS socio-technical innovation.
- Full Text:
- Date Issued: 2019
- Authors: Jalasi, Experencia Madalitso
- Date: 2019
- Subjects: Stoves, Wood -- Technological innovations -- Malawi , Biomass stoves -- Malawi , Economic development projects -- Environmental aspects -- Malawi , Rural development projects -- Environmental aspects -- Malawi
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68170 , vital:29212
- Description: This study investigates and expands learning within and between activity systems working with Improved Cook Stoves (hereafter ICS) in Malawi. The study focuses on how existing learning interactions among ICS actors can be expanded using expansive learning processes, mobilised through Boundary Crossing Change Laboratories (BCCL) to potentially inform more sustained uptake and utilisation of the ICS technology. The ICS, as a socio-technical innovation, seeks to respond to climate change mitigation and adaptation efforts in the country. However, sustained uptake and utilisation has been problematic. The study is located in the field of Environmental Education, with emphasis on the diffusion and adoption of socio-technical innovations in the context of ICS technology. The study addresses societal environmental health risks faced by people using traditional biomass fuels indoors on open fires, commonly referred to as Three Stone Fire (hereafter TSF) through formative intervention supported by Developmental Work Research (hereafter DWR) or Expansive Learning. The study was conducted in three climate change hotspot districts in Malawi: Balaka, Dedza and Mzimba. The case studies are in each of the three administrative regions of the country. Chapita Village case study is in Balaka district, in the Southern region; Waziloya Makwakwa Village is in Mzimba district in the Northern region; and Chilije Village in Dedza district in the Central region. In order to engage the potential for transformation in study areas, I divided the study into two phases. The first phase involved collection of ethnographic data to more deeply understand the context of the problem including existing learning approaches. This informed the second phase, which focused on expansive learning processes in the Chapita and Waziloya Makwakwa case studies. The study used a formative intervention approach, which focused on supporting the actors to manage the challenges they were facing and work out the problematic situations in their joint activity. The study employed a qualitative intensive research design because it aimed at in-depth understanding of uptake and utilisation of ICS. This was an important foundation for improving the existing situations through co-creating solutions with research participants. With this generative and action-oriented approach, the study employed a multiple embedded case study design. CHAT and Critical Realism were the two main theories that I employed as they resonated with the transformative interest of the study through focusing on learning as an emancipatory process with potential for transformation of human practices. In addition, I used the methodological theory of Expansive Learning from CHAT to guide the expansive learning processes. With the critical realist framing of the study, I employed a critical realist analytical framework, and used inductive, abductive and retroductive analyses.The major findings of the study indicate that broadly, uptake and utilisation of ICS is problematic, hence unsustained. The findings indicate that the majority of end-users in Chapita and Chilije case studies switched between TSF and ICS, or abandoned the ICS, which was not the case in Waziloya Makwakwa case study. The underlying causal mechanisms that appear to explain and influence end-users’ actions in all the case studies were the search for convenience during the cooking activity. Further, findings revealed that learning interactions among activity systems were unidirectional which provides evidence for top-down approaches prevalent in cook stove dissemination. The findings also indicated that most of the learning taking place was informative, not transformative. It was also inadequate, particularly for end-users. A causal mechanism that appears to shape how actors are learning ICS technology is poverty, which results in over-reliance on donor-driven projects. Findings also reveal that contradictions in the learning, uptake and utilisation of ICS influence the profile of uptake and utilisation of ICSs. Further, the change-oriented learning processes, as carried out in the Chapita and Waziloya Makwakwa case studies, have shown their potential in expanding learning interactions among ICS actors, evoking and supporting their transformative agency and enhancing their reflexivity. These processes are crucial in development and sustaining learning and change in the uptake and utilisation of ICS innovation. The main contribution of the study is methodological. It contributes broadly to diffusion and adoption of socio-technical innovations through change-oriented expansive learning processes. The study generated an Innovative Extension and Communicative Methodology, which foregrounds interaction and learning and links the socio-technical innovation intention and socio-technical innovation uptake and utilisation that potentially informs the dissemination and implementation of ICS projects. Further, the study contributes to community education by mobilising communities to address contradictions, absences, or ills in the society via change-oriented learning processes. The societal ills facing the case study sites and the areas around them, caused by climate change and variability and deforestation exacerbate the lives of rural women who are afflicted by conditions of poverty. The study contributes to global and local efforts and initiatives to address environmental health risks faced by people using traditional biomass fuels indoors on TSF and climate change mitigation and adaptation. This study has found out that putting the agency of the end-user in the centre in socio-technical transitions through context-based problem resolution and rigorous deliberate1 mediated processes of participation and learning, which allows multivoicedness and takes power relations into account, catalyses transformative agency, reflexivity, collaboration and learning capacity of ICS actors for sustained uptake and utilisation of the ICS socio-technical innovation.
- Full Text:
- Date Issued: 2019
Charting freedom: inequality beliefs, preferences for redistribution, and distributive social policy in contemporary South Africa
- Authors: Roberts, Benjamin J
- Date: 2019
- Subjects: South Africa -- Economic conditions South Africa -- Economic policy South Africa -- Social policy , Democracy -- Economic conditions -- South Africa Race discrimination -- South Africa Poverty -- South Africa Equality -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64999 , vital:28644
- Description: While the transition to democracy in South Africa extended civil and political rights and freedoms to all South Africans, there has been disagreement over the preferred nature and scope of social rights within post-apartheid society, reflecting debates over the trajectory of economic policy. Appreciable developmental gains have been made by the state over the last quarter-century, yet the challenges of poverty, unemployment and inequality persist, coupled with mounting popular discontent with the pace of transformation and political accountability. This has led to fundamental questions about social justice, restitution, and the kind of society we wish to promote. Appeals for a more inclusive, transformative social policy have also emerged, arguing that a wider vision of society is required involving multiple government responsibilities and informed by an ethic of equality and social solidarity. Against this background, in this thesis I study the views of the South African public towards economic inequality, general preferences for government-led redistribution, as well as support for social policies intended to promote racial and economic transformation. The research has been guided by several overarching questions: To what extent do South Africans share common general beliefs about material inequality? Does the public exhibit a preference for government redistribution in principle? And how unified or polarised are South Africans in their support for specific redress policies in the country? Responding to these questions has been achieved by drawing on unique, nationally representative data from the South African Social Attitudes Survey (SASAS), which has enabled me to chart social attitudes over a period of almost fifteen years between late 2003 and early 2017. Use has also been made of social citizenship as a guiding conceptual framework to understanding social policy predispositions and analysing attitudinal change. The results demonstrate that the public is united in its awareness of and deep concern about economic inequality. Since the early 2000s, a significant majority has consistently expressed the view that the income gap in the country is too large, articulated a strong preference for a more equitable social structure, and acknowledged the class and social tensions that economic inequality has produced. There is also a preference for a narrowing of earnings disparities, a more generous minimum wage, and regulatory limits on executive pay. While this suggests a desire for fair and legitimate remuneration, the analysis also reveals that South Africans are willing to tolerate fairly high levels of inequality. Nonetheless, these beliefs are generally interpreted as a desire for a more equitable and fair society. This preference for change is reflected in a fairly strong belief that government should assume responsibility for reducing material disparities. One’s social position, mobility history, awareness of inequality, political leaning and racial attitudes all have a bearing on how weak and strong this predisposition is, but the normative demand for political redistribution remains fairly widely shared irrespective of these individual traits. Greater polarisation is however evident with respect to redistributive social policy, especially measures designed to overcome historical racial injustice (affirmative action, sports quotas, and land reform). These intergroup differences converge considerably when referring to class-based policy measures. One surprising finding is the evidence that South Africa’s youngest generation, the so-called ‘Born Frees’, tend to adopt a similar predisposition to redress policy as older generations, thus confounding expectations of a post-apartheid value change. I conclude by arguing that there seems to be a firmer basis for a social compact about preferences for interventions designed to produce a more just society than is typically assumed. Intractably high levels of economic inequality during the country’s first quarter-century of democracy is resulting in a growing recognition of the need for a stronger policy emphasis on economic inequality in South Africa over coming decades if the vision enshrined in the Freedom Charter and the Constitution is to be realised. South Africans may not be able to fully agree about the specific elements that constitute a socially just response to economic inequality. Yet, the common identification of and concern with redressable injustice, coupled with a broad-based commitment to government redistribution and classbased social policies, could serve as a foundation on which to rekindle the solidaristic spirit of 1994 and forge progress towards a more equitable society.
- Full Text:
- Date Issued: 2019
- Authors: Roberts, Benjamin J
- Date: 2019
- Subjects: South Africa -- Economic conditions South Africa -- Economic policy South Africa -- Social policy , Democracy -- Economic conditions -- South Africa Race discrimination -- South Africa Poverty -- South Africa Equality -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64999 , vital:28644
- Description: While the transition to democracy in South Africa extended civil and political rights and freedoms to all South Africans, there has been disagreement over the preferred nature and scope of social rights within post-apartheid society, reflecting debates over the trajectory of economic policy. Appreciable developmental gains have been made by the state over the last quarter-century, yet the challenges of poverty, unemployment and inequality persist, coupled with mounting popular discontent with the pace of transformation and political accountability. This has led to fundamental questions about social justice, restitution, and the kind of society we wish to promote. Appeals for a more inclusive, transformative social policy have also emerged, arguing that a wider vision of society is required involving multiple government responsibilities and informed by an ethic of equality and social solidarity. Against this background, in this thesis I study the views of the South African public towards economic inequality, general preferences for government-led redistribution, as well as support for social policies intended to promote racial and economic transformation. The research has been guided by several overarching questions: To what extent do South Africans share common general beliefs about material inequality? Does the public exhibit a preference for government redistribution in principle? And how unified or polarised are South Africans in their support for specific redress policies in the country? Responding to these questions has been achieved by drawing on unique, nationally representative data from the South African Social Attitudes Survey (SASAS), which has enabled me to chart social attitudes over a period of almost fifteen years between late 2003 and early 2017. Use has also been made of social citizenship as a guiding conceptual framework to understanding social policy predispositions and analysing attitudinal change. The results demonstrate that the public is united in its awareness of and deep concern about economic inequality. Since the early 2000s, a significant majority has consistently expressed the view that the income gap in the country is too large, articulated a strong preference for a more equitable social structure, and acknowledged the class and social tensions that economic inequality has produced. There is also a preference for a narrowing of earnings disparities, a more generous minimum wage, and regulatory limits on executive pay. While this suggests a desire for fair and legitimate remuneration, the analysis also reveals that South Africans are willing to tolerate fairly high levels of inequality. Nonetheless, these beliefs are generally interpreted as a desire for a more equitable and fair society. This preference for change is reflected in a fairly strong belief that government should assume responsibility for reducing material disparities. One’s social position, mobility history, awareness of inequality, political leaning and racial attitudes all have a bearing on how weak and strong this predisposition is, but the normative demand for political redistribution remains fairly widely shared irrespective of these individual traits. Greater polarisation is however evident with respect to redistributive social policy, especially measures designed to overcome historical racial injustice (affirmative action, sports quotas, and land reform). These intergroup differences converge considerably when referring to class-based policy measures. One surprising finding is the evidence that South Africa’s youngest generation, the so-called ‘Born Frees’, tend to adopt a similar predisposition to redress policy as older generations, thus confounding expectations of a post-apartheid value change. I conclude by arguing that there seems to be a firmer basis for a social compact about preferences for interventions designed to produce a more just society than is typically assumed. Intractably high levels of economic inequality during the country’s first quarter-century of democracy is resulting in a growing recognition of the need for a stronger policy emphasis on economic inequality in South Africa over coming decades if the vision enshrined in the Freedom Charter and the Constitution is to be realised. South Africans may not be able to fully agree about the specific elements that constitute a socially just response to economic inequality. Yet, the common identification of and concern with redressable injustice, coupled with a broad-based commitment to government redistribution and classbased social policies, could serve as a foundation on which to rekindle the solidaristic spirit of 1994 and forge progress towards a more equitable society.
- Full Text:
- Date Issued: 2019
The role of leadership in shaping school culture in a secondary school
- Authors: Kofi, Linda
- Date: 2019
- Subjects: Educational leadership , Educational leadership -- South Africa -- Eastern Cape -- Case studies , Corporate culture
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/92247 , vital:30698
- Description: SDG 4 calls for an “inclusive, quality and equitable education and lifelong opportunities for all”. The purpose of the study is to investigate how leadership has shaped the school culture, which culminates to higher academic performance in a secondary school. This case study is done in a previously disadvantaged secondary school within the Buffalo City Metro Education District, in the Eastern Cape. Despite the socio-economic challenges faced by the school, the NSC examination pass rate results for the school are constantly above the Provincial NSC pass rate results. Consequently, the aim of the study is to determine the unique characteristics of the school culture that have contributed to high academic performance, and how the school leadership has cultivated this culture. The study reviews school culture using Schein’s organizational culture model. Moreover, it reviews school principalship, leadership and how leadership shapes school culture. Lastly, the study reviews literature on instructional, transformational and distributed leadership theories, as they resonate well with South African school environment. The study utilizes a qualitative research method in its investigation, gathering data through document analysis and interviews. After the data was collected, the pattern matching method was utilized to analyse the findings. The key characteristics of school culture that contributed to the school performing well academically, are the values of disciplined hard work and academic excellence. Furthermore, findings proved that characteristics of instructional leadership such as the provision of professional development and the management of curriculum and instruction have the shape the school culture. Transformational leadership characteristics such as individualized consideration, inspirational motivation and intellectual stimulation, have also shaped the school culture; as have characteristics of distributed leadership such as sharing authority and accountability. The study discusses the findings and then concludes by recognizing the research limitations such as the time constraints and purposeful exclusion of certain school members, for example learners. In its conclusion the study presents it contributions to the body of knowledge and provides recommendations for practitioners and future studies.
- Full Text:
- Date Issued: 2019
- Authors: Kofi, Linda
- Date: 2019
- Subjects: Educational leadership , Educational leadership -- South Africa -- Eastern Cape -- Case studies , Corporate culture
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/92247 , vital:30698
- Description: SDG 4 calls for an “inclusive, quality and equitable education and lifelong opportunities for all”. The purpose of the study is to investigate how leadership has shaped the school culture, which culminates to higher academic performance in a secondary school. This case study is done in a previously disadvantaged secondary school within the Buffalo City Metro Education District, in the Eastern Cape. Despite the socio-economic challenges faced by the school, the NSC examination pass rate results for the school are constantly above the Provincial NSC pass rate results. Consequently, the aim of the study is to determine the unique characteristics of the school culture that have contributed to high academic performance, and how the school leadership has cultivated this culture. The study reviews school culture using Schein’s organizational culture model. Moreover, it reviews school principalship, leadership and how leadership shapes school culture. Lastly, the study reviews literature on instructional, transformational and distributed leadership theories, as they resonate well with South African school environment. The study utilizes a qualitative research method in its investigation, gathering data through document analysis and interviews. After the data was collected, the pattern matching method was utilized to analyse the findings. The key characteristics of school culture that contributed to the school performing well academically, are the values of disciplined hard work and academic excellence. Furthermore, findings proved that characteristics of instructional leadership such as the provision of professional development and the management of curriculum and instruction have the shape the school culture. Transformational leadership characteristics such as individualized consideration, inspirational motivation and intellectual stimulation, have also shaped the school culture; as have characteristics of distributed leadership such as sharing authority and accountability. The study discusses the findings and then concludes by recognizing the research limitations such as the time constraints and purposeful exclusion of certain school members, for example learners. In its conclusion the study presents it contributions to the body of knowledge and provides recommendations for practitioners and future studies.
- Full Text:
- Date Issued: 2019
Investigating mathematical proficiency testing in Namibian school high stakes mathematics examinations: an exploratory study
- Authors: Ndjendja, Elizabeth
- Date: 2019
- Subjects: Education and state -- Namibia , Educational tests and measurements -- Namibia , Mathematics -- Curricula -- Namibia , Mathematics -- Study and teaching -- Namibia , Namibia. Ministry of Education -- Examinations
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92887 , vital:30759
- Description: The Namibian government has put processes in place to continuously improve its education system in line with educational development in the world. The education reform efforts are administered and coordinated by the Ministry of Education, Arts and Culture. At the centre of these reform efforts are curriculum policy documents and subject syllabuses with the intention of improving the teaching and learning process in the classrooms. These reform efforts appears to overlook the positive influence high stakes assessment has on the teaching and learning process. The study reported in this thesis was designed to investigate the feasibility of assessing separate elements of mathematical proficiency in the high stakes Mathematics assessment in Namibia. The study was designed as a developmental, exploratory research that collected and analysed both qualitative and quantitative data in order to respond to issues raised by five specific research objectives. The data collected enabled the adaptation of some assessment tools in order to distinctly assess selected mathematical proficiency categories. The results further indicated that the envisaged proficiency assessment system could be used to characterise the examination question papers and revealed insights into the conceptualisation of the current assessment system. The results further indicated the visible distinguishability of different elements of proficiency through the developed tools and the learners’ responses to the NSSCO examination. Finally, constrains and affordance which the original assessment system has in relation to the developed system were revealed and addressed. In closing, the research suggested changes and possible adaptation of assessment tools to ensure the proper assessment of mathematical proficiency aspects through high stakes assessment. Immerging issues that needed further research were also highlighted.
- Full Text:
- Date Issued: 2019
- Authors: Ndjendja, Elizabeth
- Date: 2019
- Subjects: Education and state -- Namibia , Educational tests and measurements -- Namibia , Mathematics -- Curricula -- Namibia , Mathematics -- Study and teaching -- Namibia , Namibia. Ministry of Education -- Examinations
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92887 , vital:30759
- Description: The Namibian government has put processes in place to continuously improve its education system in line with educational development in the world. The education reform efforts are administered and coordinated by the Ministry of Education, Arts and Culture. At the centre of these reform efforts are curriculum policy documents and subject syllabuses with the intention of improving the teaching and learning process in the classrooms. These reform efforts appears to overlook the positive influence high stakes assessment has on the teaching and learning process. The study reported in this thesis was designed to investigate the feasibility of assessing separate elements of mathematical proficiency in the high stakes Mathematics assessment in Namibia. The study was designed as a developmental, exploratory research that collected and analysed both qualitative and quantitative data in order to respond to issues raised by five specific research objectives. The data collected enabled the adaptation of some assessment tools in order to distinctly assess selected mathematical proficiency categories. The results further indicated that the envisaged proficiency assessment system could be used to characterise the examination question papers and revealed insights into the conceptualisation of the current assessment system. The results further indicated the visible distinguishability of different elements of proficiency through the developed tools and the learners’ responses to the NSSCO examination. Finally, constrains and affordance which the original assessment system has in relation to the developed system were revealed and addressed. In closing, the research suggested changes and possible adaptation of assessment tools to ensure the proper assessment of mathematical proficiency aspects through high stakes assessment. Immerging issues that needed further research were also highlighted.
- Full Text:
- Date Issued: 2019
Truth and reconciliation and other stories: a critical multimodal investigation of representations of post-apartheid South Africa in children's picturebooks: volume 1
- Authors: Smith, Jade
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97614 , vital:31458
- Description: Expected release date-April 2021
- Full Text: false
- Date Issued: 2019
- Authors: Smith, Jade
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97614 , vital:31458
- Description: Expected release date-April 2021
- Full Text: false
- Date Issued: 2019
A social capital analysis of citizen participation and service delivery in metropolitan government in Zimbabwe: the case of Glenview, Harare since 2013
- Authors: Sachikonye, Tafadzwa I
- Date: 2019
- Subjects: Social capital (Sociology) -- Zimbabwe -- Harare , Municipal services -- Zimbabwe -- Harare , Local government -- Zimbabwe -- Harare , Public administration -- Zimbabwe -- Harare , Citizen particpation -- Zimbabwe -- Harare , Local government --Citizen participation -- Zimbabwe -- Harare , Harare (Zimbabwe). City Council
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96236 , vital:31253
- Description: Significant challenges exist in contemporary Zimbabwe with regard to urban government, including with specific reference to citizenship participation and service delivery capacities. One of the crucial factors considered in the existing literature when examining urban government is the extent to which the central government intrudes in the affairs of urban government. This is particularly important given that, in recent years, many urban governments have been controlled by the main opposition party in the country. In this context, the thesis offers a critical examination of urban government in contemporary Zimbabwe by focusing on urban government in Harare (the capital) and, even more specifically, on the high-density, low-income area of Glenview. Harare is one of two metropolitan urban areas in Zimbabwe, along with Bulawayo, and is governed by the Harare City Council. While the central state’s relationship with urban governments (including Harare) in Zimbabwe is important, and is examined in this thesis, the primary concern is how this and other factors affect citizenship participation and service delivery in Harare. In pursuing this, the thesis draws upon social capital theory (including questions around trust and networks) to facilitate a critical analysis of urban government, citizenship participation and service delivery in Harare and Glenview specifically. The fieldwork for this thesis involved a qualitative research methodology, including informal interviews with relevant local stakeholders in Harare and associated documents. The thesis concludes that localised political, social and other contextual factors in Harare undercut the prospects for meaningful citizenship participation (with forms of social exclusion existing) and that this has negative implications for effective and efficient service delivery mechanisms.
- Full Text:
- Date Issued: 2019
- Authors: Sachikonye, Tafadzwa I
- Date: 2019
- Subjects: Social capital (Sociology) -- Zimbabwe -- Harare , Municipal services -- Zimbabwe -- Harare , Local government -- Zimbabwe -- Harare , Public administration -- Zimbabwe -- Harare , Citizen particpation -- Zimbabwe -- Harare , Local government --Citizen participation -- Zimbabwe -- Harare , Harare (Zimbabwe). City Council
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96236 , vital:31253
- Description: Significant challenges exist in contemporary Zimbabwe with regard to urban government, including with specific reference to citizenship participation and service delivery capacities. One of the crucial factors considered in the existing literature when examining urban government is the extent to which the central government intrudes in the affairs of urban government. This is particularly important given that, in recent years, many urban governments have been controlled by the main opposition party in the country. In this context, the thesis offers a critical examination of urban government in contemporary Zimbabwe by focusing on urban government in Harare (the capital) and, even more specifically, on the high-density, low-income area of Glenview. Harare is one of two metropolitan urban areas in Zimbabwe, along with Bulawayo, and is governed by the Harare City Council. While the central state’s relationship with urban governments (including Harare) in Zimbabwe is important, and is examined in this thesis, the primary concern is how this and other factors affect citizenship participation and service delivery in Harare. In pursuing this, the thesis draws upon social capital theory (including questions around trust and networks) to facilitate a critical analysis of urban government, citizenship participation and service delivery in Harare and Glenview specifically. The fieldwork for this thesis involved a qualitative research methodology, including informal interviews with relevant local stakeholders in Harare and associated documents. The thesis concludes that localised political, social and other contextual factors in Harare undercut the prospects for meaningful citizenship participation (with forms of social exclusion existing) and that this has negative implications for effective and efficient service delivery mechanisms.
- Full Text:
- Date Issued: 2019
Biochemical characterization of the β-mannanase activity of Bacillus paralicheniformis SVD1
- Authors: Clarke, Matthew David
- Date: 2019
- Subjects: Mycobacterium avium paratuberculosis , Enzymes -- Biotechnology , Lignocellulose -- Biotechnology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67570 , vital:29112
- Description: Products produced via the enzymatic hydrolysis of lignocellulosic biomass, the most abundant renewable terrestrial source of carbon, can potentially replace a lot of the fuels and chemicals currently produced using non-renewable hydrocarbons. Mannan is a polysaccharide component of lignocellulose that is abundant in softwoods and legume seeds. Enzymatic hydrolysis of mannan by β-mannanases has various industrial applications, including use in biofuel and prebiotic mannooligosaccharide (MOS) production for the improvement of human and animal health. The industrial use of β-mannanases depends on their biochemical characteristics, such as their activity, stability and substrate specificity. Knowledge of their synergistic interactions with other enzymes is also useful for effective hydrolysis. Bacillus paralicheniformis SVD1 was used as a source for β-mannanases. The two mannanases of B. paralicheniformis SVD1 have not been biochemically characterized apart from minor characterization of crude β-mannanase activity. The protein sequences of the two β-mannanases, of glycosyl hydrolase family 5 and 26, have a 95% - 96% identity to the β-mannanases of B. licheniformis DSM13T (=ATCC14580T). These small protein sequence differences could lead to quite different biochemical characteristics. These mannanases were characterized as these enzymes may have industrially useful characteristics. To induce mannanase production, B. paralicheniformis SVD1 was cultured in broth containing the mannan substrate locust bean gum. Various growth curve parameters were measured over 72 h. Mannanase activity was the highest after 48 h of growth - this was the time at which mannanase activity was concentrated, using 3 kDa centrifugal filtration devices, for biochemical characterization of the crude activity. Zymography revealed that the crude concentrated mannanase fraction consisted of at least two mannanases with relative molecular weights (MWs) of 29.6 kDa and 33 kDa. This was smaller than expected – based on their theoretical molecular masses. Protease activity, which was detected in the broth, was probably the reason. There were two pH optima, pH 5.0 and pH 7.0, which also indicated the presence of two mannanases. The concentrated mannanase displayed characteristics that were expected of a B. paralicheniformis β-mannanase. The temperature optimum was 50°C and the activity loss was less than 7% at 50°C after 24 h. Substrate specificity assays revealed that there was predominantly mannanase activity present. Thin layer chromatography (TLC) analysis of mannan and MOS hydrolysis showed that mainly M2 and M3 MOS were produced; only MOS with a degree of polymerization of 4 or higher were hydrolyzed. Hydrolysis was minimal on mannoligosaccharides with galactose substituents. Activity and MOS production was the highest on soluble, low branched mannan substrates. The highest activity observed was on konjac glucomannan. Purification of the mannanase activity was then attempted using various methods. Ammonium sulfate precipitation, acetone precipitation, as well as centrifugal filtration device concentration was assessed for concentration of the mannanase activity.Concentration was not very successful due to low activity yields (≤ 20%). Anion exchange chromatography (AEC) and size exclusion chromatography (SEC) was used for purification. AEC gave good activity yield and fold purification, but SDS-PAGE analysis revealed the presence of many different proteins so further purification was necessary. SDS-PAGE analysis showed that there were only a few protein contaminants in the SEC fraction. However, the yield was too low to allow for biochemical characterization. The optimized purification procedure, which partially purified the mannanase activity, used 85% ammonium sulfate precipitation, followed by AEC. The fold purification was high (88.9) and the specific activity was 29.5 U.mg-1. A zymogram of the partially purified mannanase showed a mannanase active band with a MW of 40 - 41 kDa. A serine protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), was added during the purification steps. This indicated that the mannanase/s in the crude concentrate, without PMSF added, was hydrolyzed by serine protease activity. Native PAGE zymograms suggested that at least two different isoforms of mannanases were present. Additional purification would be required to determine the true characteristics of the mannanase/s. The biochemical characteristics of the crude and partially purified mannanases were similar. The pH optima of the partially purified mannanases were different; the pH optima were 6.0 and 9.0. The substrate specificities were similar, except that the partially purified mannanases displayed no cellulase and β-D-galactosidase activity, but showed a small amount of α-L-arabinase activity. The partially purified mannanase and a Cyamopsis tetragonolobus GH27 α-galactosidase synergistically hydrolyzed locust bean gum. The M50G50 combination displayed the highest extent of hydrolysis; after 24 h there was a 1.39 fold increase in reducing sugar release and the degree of synergy (DS) was 4.64. TLC analysis indicated that synergy increased the release of small MOS. These MOS could be useful as prebiotics. The synergy between the partially purified mannanase and the commercial cellulase mixture Cellic® CTec2 (Novozymes) on spent coffee grounds (SCG) was also determined. SCG is an abundant industrial waste product that has high mannan content. The SCG was pretreated using NaOH, and the monosaccharide, soluble phenolics and insoluble contents were determined. Glucose and mannose were the dominant monosaccharides in the SCG; the pretreated SCG contained 20.4% (w/w) glucose and 18.5% (w/w) mannose, respectively. The NaOH pretreatment improved mannanase hydrolysis of SCG. It resulted in the opening up and swelling of the SCG particles and removed some of the insoluble solids. The partially purified B. paralicheniformis SVD1 mannanase displayed no detectable activity on SCG, but showed synergy with CTec2, in terms of DS, on untreated and NaOH pretreated SCG. This is the first report of mannanasecellulase synergy on SCG; other studies found that increased hydrolysis was due to additive effects. The results obtained in this study are only an initial assessment of the biochemical properties of B. paralicheniformis SVD1 mannanase activity and its synergy with other enzymes. These results can be used to inform future studies.
- Full Text:
- Date Issued: 2019
- Authors: Clarke, Matthew David
- Date: 2019
- Subjects: Mycobacterium avium paratuberculosis , Enzymes -- Biotechnology , Lignocellulose -- Biotechnology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67570 , vital:29112
- Description: Products produced via the enzymatic hydrolysis of lignocellulosic biomass, the most abundant renewable terrestrial source of carbon, can potentially replace a lot of the fuels and chemicals currently produced using non-renewable hydrocarbons. Mannan is a polysaccharide component of lignocellulose that is abundant in softwoods and legume seeds. Enzymatic hydrolysis of mannan by β-mannanases has various industrial applications, including use in biofuel and prebiotic mannooligosaccharide (MOS) production for the improvement of human and animal health. The industrial use of β-mannanases depends on their biochemical characteristics, such as their activity, stability and substrate specificity. Knowledge of their synergistic interactions with other enzymes is also useful for effective hydrolysis. Bacillus paralicheniformis SVD1 was used as a source for β-mannanases. The two mannanases of B. paralicheniformis SVD1 have not been biochemically characterized apart from minor characterization of crude β-mannanase activity. The protein sequences of the two β-mannanases, of glycosyl hydrolase family 5 and 26, have a 95% - 96% identity to the β-mannanases of B. licheniformis DSM13T (=ATCC14580T). These small protein sequence differences could lead to quite different biochemical characteristics. These mannanases were characterized as these enzymes may have industrially useful characteristics. To induce mannanase production, B. paralicheniformis SVD1 was cultured in broth containing the mannan substrate locust bean gum. Various growth curve parameters were measured over 72 h. Mannanase activity was the highest after 48 h of growth - this was the time at which mannanase activity was concentrated, using 3 kDa centrifugal filtration devices, for biochemical characterization of the crude activity. Zymography revealed that the crude concentrated mannanase fraction consisted of at least two mannanases with relative molecular weights (MWs) of 29.6 kDa and 33 kDa. This was smaller than expected – based on their theoretical molecular masses. Protease activity, which was detected in the broth, was probably the reason. There were two pH optima, pH 5.0 and pH 7.0, which also indicated the presence of two mannanases. The concentrated mannanase displayed characteristics that were expected of a B. paralicheniformis β-mannanase. The temperature optimum was 50°C and the activity loss was less than 7% at 50°C after 24 h. Substrate specificity assays revealed that there was predominantly mannanase activity present. Thin layer chromatography (TLC) analysis of mannan and MOS hydrolysis showed that mainly M2 and M3 MOS were produced; only MOS with a degree of polymerization of 4 or higher were hydrolyzed. Hydrolysis was minimal on mannoligosaccharides with galactose substituents. Activity and MOS production was the highest on soluble, low branched mannan substrates. The highest activity observed was on konjac glucomannan. Purification of the mannanase activity was then attempted using various methods. Ammonium sulfate precipitation, acetone precipitation, as well as centrifugal filtration device concentration was assessed for concentration of the mannanase activity.Concentration was not very successful due to low activity yields (≤ 20%). Anion exchange chromatography (AEC) and size exclusion chromatography (SEC) was used for purification. AEC gave good activity yield and fold purification, but SDS-PAGE analysis revealed the presence of many different proteins so further purification was necessary. SDS-PAGE analysis showed that there were only a few protein contaminants in the SEC fraction. However, the yield was too low to allow for biochemical characterization. The optimized purification procedure, which partially purified the mannanase activity, used 85% ammonium sulfate precipitation, followed by AEC. The fold purification was high (88.9) and the specific activity was 29.5 U.mg-1. A zymogram of the partially purified mannanase showed a mannanase active band with a MW of 40 - 41 kDa. A serine protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), was added during the purification steps. This indicated that the mannanase/s in the crude concentrate, without PMSF added, was hydrolyzed by serine protease activity. Native PAGE zymograms suggested that at least two different isoforms of mannanases were present. Additional purification would be required to determine the true characteristics of the mannanase/s. The biochemical characteristics of the crude and partially purified mannanases were similar. The pH optima of the partially purified mannanases were different; the pH optima were 6.0 and 9.0. The substrate specificities were similar, except that the partially purified mannanases displayed no cellulase and β-D-galactosidase activity, but showed a small amount of α-L-arabinase activity. The partially purified mannanase and a Cyamopsis tetragonolobus GH27 α-galactosidase synergistically hydrolyzed locust bean gum. The M50G50 combination displayed the highest extent of hydrolysis; after 24 h there was a 1.39 fold increase in reducing sugar release and the degree of synergy (DS) was 4.64. TLC analysis indicated that synergy increased the release of small MOS. These MOS could be useful as prebiotics. The synergy between the partially purified mannanase and the commercial cellulase mixture Cellic® CTec2 (Novozymes) on spent coffee grounds (SCG) was also determined. SCG is an abundant industrial waste product that has high mannan content. The SCG was pretreated using NaOH, and the monosaccharide, soluble phenolics and insoluble contents were determined. Glucose and mannose were the dominant monosaccharides in the SCG; the pretreated SCG contained 20.4% (w/w) glucose and 18.5% (w/w) mannose, respectively. The NaOH pretreatment improved mannanase hydrolysis of SCG. It resulted in the opening up and swelling of the SCG particles and removed some of the insoluble solids. The partially purified B. paralicheniformis SVD1 mannanase displayed no detectable activity on SCG, but showed synergy with CTec2, in terms of DS, on untreated and NaOH pretreated SCG. This is the first report of mannanasecellulase synergy on SCG; other studies found that increased hydrolysis was due to additive effects. The results obtained in this study are only an initial assessment of the biochemical properties of B. paralicheniformis SVD1 mannanase activity and its synergy with other enzymes. These results can be used to inform future studies.
- Full Text:
- Date Issued: 2019
A dynamics based analysis of allosteric modulation in heat shock proteins
- Authors: Penkler, David Lawrence
- Date: 2019
- Subjects: Heat shock proteins , Molecular chaperones , Allosteric regulation , Homeostasis , Protein kinases , Transcription factors , Adenosine triphosphatase , Cancer -- Chemotherapy , Molecular dynamics , High throughput screening (Drug development)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115948 , vital:34273
- Description: The 70 kDa and 90 kDa heat shock proteins (Hsp70 and Hsp90) are molecular chaperones that play central roles in maintaining cellular homeostasis in all organisms of life with the exception of archaea. In addition to their general chaperone function in protein quality control, Hsp70 and Hsp90 cooperate in the regulation and activity of some 200 known natively folded protein clients which include protein kinases, transcription factors and receptors, many of which are implicated as key regulators of essential signal transduction pathways. Both chaperones are considered to be large multi-domain proteins that rely on ATPase activity and co-chaperone interactions to regulate their conformational cycles for peptide binding and release. The unique positioning of Hsp90 at the crossroads of several fundamental cellular pathways coupled with its known association with diverse oncogenic peptide clients has brought the molecular chaperone under increasing interest as a potential anti-cancer target that is crucially implicated with all eight hallmarks of the disease. Current orthosteric drug discovery efforts aimed at the inhibition of the ATPase domain of Hsp90 have been limited due to high levels of associated toxicity. In an effort to circumnavigate this, the combined focus of research efforts is shifting toward alternative approaches such as interference with co-chaperone binding and the allosteric inhibition/activation of the molecular chaperone. The overriding aim of this thesis was to demonstrate how the computational technique of Perturbation response scanning (PRS) coupled with all-atom molecular dynamics simulations (MD) and dynamic residue interaction network (DRN) analysis can be used as a viable strategy to efficiently scan and accurately identify allosteric control element capable of modulating the functional dynamics of a protein. In pursuit of this goal, this thesis also contributes to the current understanding of the nucleotide dependent allosteric mechanisms at play in cellular functionality of both Hsp70 and Hsp90. All-atom MD simulations of E. coli DnaK provided evidence of nucleotide driven modulation of conformational dynamics in both the catalytically active and inactive states. PRS analysis employed on these trajectories demonstrated sensitivity toward bound nucleotide and peptide substrate, and provided evidence of a putative allosterically active intermediate state between the ATPase active and inactive conformational states. Simultaneous binding of ATP and peptide substrate was found to allosterically prime the chaperone for interstate conversion regardless of the transition direction. Detailed analysis of these allosterically primed states revealed select residue sites capable of selecting a coordinate shift towards the opposite conformational state. In an effort to validate these results, the predicted allosteric hot spot sites were cross-validated with known experimental works and found to overlap with functional sites implicated in allosteric signal propagation and ATPase activation in Hsp70. This study presented for the first time, the application of PRS as a suitable diagnostic tool for the elucidation and quantification of the allosteric potential of select residues to effect functionally relevant global conformational rearrangements. The PRS methodology described in this study was packaged within the Python programming environment in the MD-TASK software suite for command-line ease of use and made freely available. Homology modelling techniques were used to address the lack of experimental structural data for the human cytosolic isoform of Hsp90 and for the first time provided accurate full-length structural models of human Hsp90α in fully-closed and partially-open conformations. Long-range all-atom MD simulations of these structures revealed nucleotide driven modulation of conformational dynamics in Hsp90. Subsequent DRN and PRS analysis of these MD trajectories allowed for the quantification and elucidation of nucleotide driven allosteric modulation in the molecular chaperone. A detailed PRS analysis revealed allosteric inter-domain coupling between the extreme terminals of the chaperone in response to external force perturbations at either domain. Furthermore PRS also identified several individual residue sites that are capable of selecting conformational rearrangements towards functionally relevant states which may be considered to be putative allosteric target sites for future drug discovery efforts Molecular docking techniques were employed to investigate the modulation of conformational dynamics of human Hsp90α in response to ligand binding interactions at two identified allosteric sites at the C-terminal. High throughput screening of a small library of natural compounds indigenous to South Africa revealed three hit compounds at these sites: Cephalostatin 17, 20(29)-Lupene-3β isoferulate and 3'-Bromorubrolide F. All-atom MD simulations on these protein-ligand complexes coupled with DRN analysis and several advanced trajectory based analysis techniques provided evidence of selective allosteric modulation of Hsp90α conformational dynamics in response to the identity and location of the bound ligands. Ligands bound at the four-helix bundle presented as putative allosteric inhibitors of Hsp90α, driving conformational dynamics in favour of dimer opening and possibly dimer separation. Meanwhile, ligand interactions at an adjacent sub-pocket located near the interface between the middle and C-terminal domains demonstrated allosteric activation of the chaperone, modulating conformational dynamics in favour of the fully-closed catalytically active conformational state. Taken together, the data presented in this thesis contributes to the understanding of allosteric modulation of conformational dynamics in Hsp70 and Hsp90, and provides a suitable platform for future biochemical and drug discovery studies. Furthermore, the molecular docking and computational identification of allosteric compounds with suitable binding affinity for allosteric sites at the CTD of human Hsp90α provide for the first time “proof-of-principle” for the use of PRS in conjunction with MD simulations and DRN analysis as a suitable method for the rapid identification of allosteric sites in proteins that can be probed by small molecule interaction. The data presented in this section could pave the way for future allosteric drug discovery studies for the treatment of Hsp90 associated pathologies.
- Full Text:
- Date Issued: 2019
- Authors: Penkler, David Lawrence
- Date: 2019
- Subjects: Heat shock proteins , Molecular chaperones , Allosteric regulation , Homeostasis , Protein kinases , Transcription factors , Adenosine triphosphatase , Cancer -- Chemotherapy , Molecular dynamics , High throughput screening (Drug development)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115948 , vital:34273
- Description: The 70 kDa and 90 kDa heat shock proteins (Hsp70 and Hsp90) are molecular chaperones that play central roles in maintaining cellular homeostasis in all organisms of life with the exception of archaea. In addition to their general chaperone function in protein quality control, Hsp70 and Hsp90 cooperate in the regulation and activity of some 200 known natively folded protein clients which include protein kinases, transcription factors and receptors, many of which are implicated as key regulators of essential signal transduction pathways. Both chaperones are considered to be large multi-domain proteins that rely on ATPase activity and co-chaperone interactions to regulate their conformational cycles for peptide binding and release. The unique positioning of Hsp90 at the crossroads of several fundamental cellular pathways coupled with its known association with diverse oncogenic peptide clients has brought the molecular chaperone under increasing interest as a potential anti-cancer target that is crucially implicated with all eight hallmarks of the disease. Current orthosteric drug discovery efforts aimed at the inhibition of the ATPase domain of Hsp90 have been limited due to high levels of associated toxicity. In an effort to circumnavigate this, the combined focus of research efforts is shifting toward alternative approaches such as interference with co-chaperone binding and the allosteric inhibition/activation of the molecular chaperone. The overriding aim of this thesis was to demonstrate how the computational technique of Perturbation response scanning (PRS) coupled with all-atom molecular dynamics simulations (MD) and dynamic residue interaction network (DRN) analysis can be used as a viable strategy to efficiently scan and accurately identify allosteric control element capable of modulating the functional dynamics of a protein. In pursuit of this goal, this thesis also contributes to the current understanding of the nucleotide dependent allosteric mechanisms at play in cellular functionality of both Hsp70 and Hsp90. All-atom MD simulations of E. coli DnaK provided evidence of nucleotide driven modulation of conformational dynamics in both the catalytically active and inactive states. PRS analysis employed on these trajectories demonstrated sensitivity toward bound nucleotide and peptide substrate, and provided evidence of a putative allosterically active intermediate state between the ATPase active and inactive conformational states. Simultaneous binding of ATP and peptide substrate was found to allosterically prime the chaperone for interstate conversion regardless of the transition direction. Detailed analysis of these allosterically primed states revealed select residue sites capable of selecting a coordinate shift towards the opposite conformational state. In an effort to validate these results, the predicted allosteric hot spot sites were cross-validated with known experimental works and found to overlap with functional sites implicated in allosteric signal propagation and ATPase activation in Hsp70. This study presented for the first time, the application of PRS as a suitable diagnostic tool for the elucidation and quantification of the allosteric potential of select residues to effect functionally relevant global conformational rearrangements. The PRS methodology described in this study was packaged within the Python programming environment in the MD-TASK software suite for command-line ease of use and made freely available. Homology modelling techniques were used to address the lack of experimental structural data for the human cytosolic isoform of Hsp90 and for the first time provided accurate full-length structural models of human Hsp90α in fully-closed and partially-open conformations. Long-range all-atom MD simulations of these structures revealed nucleotide driven modulation of conformational dynamics in Hsp90. Subsequent DRN and PRS analysis of these MD trajectories allowed for the quantification and elucidation of nucleotide driven allosteric modulation in the molecular chaperone. A detailed PRS analysis revealed allosteric inter-domain coupling between the extreme terminals of the chaperone in response to external force perturbations at either domain. Furthermore PRS also identified several individual residue sites that are capable of selecting conformational rearrangements towards functionally relevant states which may be considered to be putative allosteric target sites for future drug discovery efforts Molecular docking techniques were employed to investigate the modulation of conformational dynamics of human Hsp90α in response to ligand binding interactions at two identified allosteric sites at the C-terminal. High throughput screening of a small library of natural compounds indigenous to South Africa revealed three hit compounds at these sites: Cephalostatin 17, 20(29)-Lupene-3β isoferulate and 3'-Bromorubrolide F. All-atom MD simulations on these protein-ligand complexes coupled with DRN analysis and several advanced trajectory based analysis techniques provided evidence of selective allosteric modulation of Hsp90α conformational dynamics in response to the identity and location of the bound ligands. Ligands bound at the four-helix bundle presented as putative allosteric inhibitors of Hsp90α, driving conformational dynamics in favour of dimer opening and possibly dimer separation. Meanwhile, ligand interactions at an adjacent sub-pocket located near the interface between the middle and C-terminal domains demonstrated allosteric activation of the chaperone, modulating conformational dynamics in favour of the fully-closed catalytically active conformational state. Taken together, the data presented in this thesis contributes to the understanding of allosteric modulation of conformational dynamics in Hsp70 and Hsp90, and provides a suitable platform for future biochemical and drug discovery studies. Furthermore, the molecular docking and computational identification of allosteric compounds with suitable binding affinity for allosteric sites at the CTD of human Hsp90α provide for the first time “proof-of-principle” for the use of PRS in conjunction with MD simulations and DRN analysis as a suitable method for the rapid identification of allosteric sites in proteins that can be probed by small molecule interaction. The data presented in this section could pave the way for future allosteric drug discovery studies for the treatment of Hsp90 associated pathologies.
- Full Text:
- Date Issued: 2019
Recontextualisation of biodiversity knowledge in the Senior Phase Natural Sciences curriculum
- Authors: Mmekwa, Makwena
- Date: 2019
- Subjects: Science -- Study and teaching (Secondary) -- South Africa , Biodiversity -- Study and teaching (Secondary) -- South Africa , Environmental protection -- South Africa , Biodiversity Conservation -- South Africa , Millennium Ecosystem Assessment (Program) , South African National Biodiversity Institute. Life: the state of South Africa's biodiversity
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/92694 , vital:30723
- Description: This study explored the nature of biodiversity knowledge in the Senior Phase Natural Sciences curriculum in relation to international and national scientific documents. Significant biodiversity key features were identified from a review of these documents. These concepts were then explored in terms of how they had been presented and recontextualised in the Senior Phase Natural Sciences CAPS policy document and a selection of three commonly used textbooks for this subject in South Africa. Using Bernstein’s (1990) framework of the Pedagogic Device, the study traces how biodiversity knowledge was de-located from the scientific Field of Production (FOP) and relocated into the Official Recontextualisation Field (ORF) and Pedagogical Recontextualisation Field (PRF). In exploring the continuity, changes and discontinuities in the biodiversity content, as it has been recontextualised, the study utilised Bernstein’s concepts of selective appropriation and ideological transformation. The study is a qualitative case study that drew on document analysis and structured interviews to generate data. Data analysis for this study consisted of two phases. Phase One involved an analysis of biodiversity knowledge in the Millennium Ecosystem Assessment (MEA, 2005) and Life: The State of South Africa’s Biodiversity (SANBI, 2013) which represented the FOP. This was in order to explore the nature of biodiversity knowledge in those documents. This knowledge was then compared to the Senior Phase Natural Sciences curriculum which represented the ORF and selection of textbooks representing the PRF. Phase Two sought to investigate the role players in the recontextualising fields and what roles did they play in the recontextualisation of biodiversity knowledge. This phase entailed an analysis of interviews. The findings showed that both the international document and the national document presented biodiversity knowledge in terms of their fundamental value to humans. In addition, these documents illustrated human-environmental interactions. They presented procedural knowledge that allow us to understand ecosystems and their services to human well-being. The documents also described how ecosystem services are in decline in many places around the world. The documents presented knowledge of threats to biodiversity such as habitat loss, invasive species, pollution, and overharvesting. They also included knowledge of conservation and sustainability which focused on preventing ongoing degradation and restoration and reversal of degradation of ecosystems. In comparing the ORF and the PRF this study showed that the CAPS policy document appears to present concepts foundational to understanding biodiversity rather than discussing biodiversity itself. The textbooks contextualise these foundational concepts and broaden them mostly through pictorial illustrations, as case studies and contextual examples. A recommendation from the research is that the official recontextualisation process should review opportunities to draw on international and national documents that present concepts and contemporary cases of biodiversity content knowledge to ensure that the complexities around biodiversity are presented in the curriculum. This study may contribute to the development and review of the Natural Sciences curriculum and environmental education in South Africa. The study also suggests areas of biodiversity knowledge that might be included as curriculum content in the future. It further suggests that curriculum developers consider including new environmental knowledge which deals with local, national and global needs and expectations.
- Full Text:
- Date Issued: 2019
- Authors: Mmekwa, Makwena
- Date: 2019
- Subjects: Science -- Study and teaching (Secondary) -- South Africa , Biodiversity -- Study and teaching (Secondary) -- South Africa , Environmental protection -- South Africa , Biodiversity Conservation -- South Africa , Millennium Ecosystem Assessment (Program) , South African National Biodiversity Institute. Life: the state of South Africa's biodiversity
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/92694 , vital:30723
- Description: This study explored the nature of biodiversity knowledge in the Senior Phase Natural Sciences curriculum in relation to international and national scientific documents. Significant biodiversity key features were identified from a review of these documents. These concepts were then explored in terms of how they had been presented and recontextualised in the Senior Phase Natural Sciences CAPS policy document and a selection of three commonly used textbooks for this subject in South Africa. Using Bernstein’s (1990) framework of the Pedagogic Device, the study traces how biodiversity knowledge was de-located from the scientific Field of Production (FOP) and relocated into the Official Recontextualisation Field (ORF) and Pedagogical Recontextualisation Field (PRF). In exploring the continuity, changes and discontinuities in the biodiversity content, as it has been recontextualised, the study utilised Bernstein’s concepts of selective appropriation and ideological transformation. The study is a qualitative case study that drew on document analysis and structured interviews to generate data. Data analysis for this study consisted of two phases. Phase One involved an analysis of biodiversity knowledge in the Millennium Ecosystem Assessment (MEA, 2005) and Life: The State of South Africa’s Biodiversity (SANBI, 2013) which represented the FOP. This was in order to explore the nature of biodiversity knowledge in those documents. This knowledge was then compared to the Senior Phase Natural Sciences curriculum which represented the ORF and selection of textbooks representing the PRF. Phase Two sought to investigate the role players in the recontextualising fields and what roles did they play in the recontextualisation of biodiversity knowledge. This phase entailed an analysis of interviews. The findings showed that both the international document and the national document presented biodiversity knowledge in terms of their fundamental value to humans. In addition, these documents illustrated human-environmental interactions. They presented procedural knowledge that allow us to understand ecosystems and their services to human well-being. The documents also described how ecosystem services are in decline in many places around the world. The documents presented knowledge of threats to biodiversity such as habitat loss, invasive species, pollution, and overharvesting. They also included knowledge of conservation and sustainability which focused on preventing ongoing degradation and restoration and reversal of degradation of ecosystems. In comparing the ORF and the PRF this study showed that the CAPS policy document appears to present concepts foundational to understanding biodiversity rather than discussing biodiversity itself. The textbooks contextualise these foundational concepts and broaden them mostly through pictorial illustrations, as case studies and contextual examples. A recommendation from the research is that the official recontextualisation process should review opportunities to draw on international and national documents that present concepts and contemporary cases of biodiversity content knowledge to ensure that the complexities around biodiversity are presented in the curriculum. This study may contribute to the development and review of the Natural Sciences curriculum and environmental education in South Africa. The study also suggests areas of biodiversity knowledge that might be included as curriculum content in the future. It further suggests that curriculum developers consider including new environmental knowledge which deals with local, national and global needs and expectations.
- Full Text:
- Date Issued: 2019
Secret sex lives in the intertidal: insights into the mating systems of clinid fishes from molecular parentage analyses
- Authors: Scheeper, Martinus Johannes
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72438 , vital:30048
- Description: Expected release date-April 2020
- Full Text: false
- Date Issued: 2019
- Authors: Scheeper, Martinus Johannes
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72438 , vital:30048
- Description: Expected release date-April 2020
- Full Text: false
- Date Issued: 2019
An assessment of amount, distribution and use of urban green spaces in small towns of the Eastern Cape
- Authors: Radebe, Denis Siphosihle
- Date: 2019
- Subjects: Urban ecology (Sociology) -- South Africa -- Eastern Cape , Small cities -- South Africa -- Eastern Cape , City planning -- South Africa -- Eastern Cape , Recreation areas -- South Africa -- Eastern Cape , Open spaces -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76447 , vital:30563
- Description: Most regions of the developing world are experiencing large-scale urbanisation, with urban population growth outstripping rural growth. This is most marked in small and medium-sized towns as opposed to megacities. Urbanisation is associated with numerous changes in social, economic and ecological states and dynamics. A key one, of interest in this study, is the sustainability and liveability of the growing towns and cities. The retention, provision and maintenance of multifunctional urban green infrastructure are a core strategy in this regard. This study therefore sought to assess the amount, distribution and use of urban green spaces within South Africa using small towns of the Eastern Cape. The primary research included sixteen aerial images of which eight were historical aerial photographs and another eight were the latest aerial images of the selected study towns. Historical and latest aerial images were digitised to classify the types and calculate the amount of urban green space. GIS mapping, interviews and focus group discussions were conducted with urban residents to understand how these green spaces are used. The analytical tools in this study derived from social science included household surveys of 180 randomly selected respondents in small towns. Fifteen types of green spaces were identified in the sample towns. The study further revealed that green spaces are not distributed equally in different suburbs of small towns, generally being less green spaces, especially formal parks and recreation areas, in poorer areas. The results indicated a decline of green spaces with urbanisation, and most marked in fast growing towns. The results suggested that urban residents frequently visited urban green spaces, with most respondents favouring the use of green spaces for social and cultural benefits. How use of different spaces was strongly gender related, with males favouring less developed green space types (such as commonages and woodlands) and females for formal areas such domestic and institutional gardens and churchyards. Respondents also identified various challenges associated with using and accessing urban green spaces, with pollution, crime and lack of maintenance in particular. The study shows the importance of GIS as a mapping tool that can be used to provide information for ecological planning in rapidly changing urban environment. The research process generated several lessons that need to be taken into consideration when designing urban landscapes, most importantly relating to the diversity, quantity, quality and maintenance of urban green spaces.
- Full Text:
- Date Issued: 2019
- Authors: Radebe, Denis Siphosihle
- Date: 2019
- Subjects: Urban ecology (Sociology) -- South Africa -- Eastern Cape , Small cities -- South Africa -- Eastern Cape , City planning -- South Africa -- Eastern Cape , Recreation areas -- South Africa -- Eastern Cape , Open spaces -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76447 , vital:30563
- Description: Most regions of the developing world are experiencing large-scale urbanisation, with urban population growth outstripping rural growth. This is most marked in small and medium-sized towns as opposed to megacities. Urbanisation is associated with numerous changes in social, economic and ecological states and dynamics. A key one, of interest in this study, is the sustainability and liveability of the growing towns and cities. The retention, provision and maintenance of multifunctional urban green infrastructure are a core strategy in this regard. This study therefore sought to assess the amount, distribution and use of urban green spaces within South Africa using small towns of the Eastern Cape. The primary research included sixteen aerial images of which eight were historical aerial photographs and another eight were the latest aerial images of the selected study towns. Historical and latest aerial images were digitised to classify the types and calculate the amount of urban green space. GIS mapping, interviews and focus group discussions were conducted with urban residents to understand how these green spaces are used. The analytical tools in this study derived from social science included household surveys of 180 randomly selected respondents in small towns. Fifteen types of green spaces were identified in the sample towns. The study further revealed that green spaces are not distributed equally in different suburbs of small towns, generally being less green spaces, especially formal parks and recreation areas, in poorer areas. The results indicated a decline of green spaces with urbanisation, and most marked in fast growing towns. The results suggested that urban residents frequently visited urban green spaces, with most respondents favouring the use of green spaces for social and cultural benefits. How use of different spaces was strongly gender related, with males favouring less developed green space types (such as commonages and woodlands) and females for formal areas such domestic and institutional gardens and churchyards. Respondents also identified various challenges associated with using and accessing urban green spaces, with pollution, crime and lack of maintenance in particular. The study shows the importance of GIS as a mapping tool that can be used to provide information for ecological planning in rapidly changing urban environment. The research process generated several lessons that need to be taken into consideration when designing urban landscapes, most importantly relating to the diversity, quantity, quality and maintenance of urban green spaces.
- Full Text:
- Date Issued: 2019
The performance and preference of a specialist herbivore, Catorhintha schaffneri (Coreidae), on its polytypic host plant, Pereskia aculeata (Cactaceae)
- Authors: Egbon, Ikponmwosa Nathaniel
- Date: 2019
- Subjects: Insects and biological pest control agents -- South Africa , Pereskia -- Biological control -- South Africa , Cactus -- Biological control -- South Africa , Coreida-- South Africa , Invasive plants -- Biological control -- South Africa , Catorhintha schaffneri
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68250 , vital:29223
- Description: Plant species moved beyond their natural ranges may be liberated into enemy-free spaces, where they increase resource allocation to fitness, rather than defence against natural enemies, and become invasive as suggested by the Evolution of Increased Competitive Ability (EICA) Hypothesis. Several cacti are notable invaders and are targeted for biological control. The leafy cactus, Pereskia aculeata Miller, introduced into South Africa from South America, has become a target for biological control after becoming invasive. The absence of natural enemies of P. aculeata in the introduced range may be the reason for its invasiveness. This thesis seeks to investigate the role of the evolution of increased competitive ability (enemy release) as the probable driver of P. aculeata’s success, and ascertain how the plant’s intraspecific variation influences the impact, fitness of, and preference by its biological control agent, Catorhintha schaffneri Brailovsky and Garcia (Coreidae), in South Africa. Enemy release and evolution of traits in P. aculeata were examined by quantifying plant growth parameters of fifteen genotypes of P. aculeata from both the native and invaded distribution of the plant. Ten genotypes of P. aculeata were used in testing the effect of agent herbivory (impact and damage) under similar conditions. These studies indicated that most invaded-range genotypes were more vigorous than the native genotypes. Rapid growth may account for the quick access of invasive genotypes of P. aculeata to tree canopies. Catorhintha schaffneri damage varied between genotypes but differences in the damage and impact from the agent could not be explained by whether the plant originated in the introduced or native distribution. In sum, while the growth of the invasive genotypes largely conforms to the EICA hypothesis, the impact of C. schaffneri did not support the hypothesis. The influence of host variation in P. aculeata on the fitness of C. schaffneri within the context of local adaptation to plant genotypes from different localities was tested using agent survival, stage-specific and total developmental time, and the extent of damage to ten host genotypes. Maw’s Host Suitability Index (HIS) and Dobie’s Susceptibility Index (DSI) showed the preference by and performance of C. schaffneri on the different genotypes of the plant. Catorhintha schaffneri survived to the adult stage on 70% of genotypes tested. Evidence consistent with the assumption that C. schaffneri would be fitter on the native genotypes than the invasive genotypes due to local adaptation was not found. In addition, there was no evidence in support of fitter agents on the invasive genotypes than on the native genotypes as proposed by EICA hypothesis. Catorhintha schaffneri developed equally well on the invasive genotypes of P. aculeata as on the native genotypes. To establish whether host variation would affect diet selection by C. schaffneri, both nymphs and adults were examined in paired-choice and multiple-choice trials. The nymphs and adults chose their hosts regardless of host genotype differences. The agent may be good at selecting good succulent shoots from bad shoots, but is incapable of distinguishing a good host genotype from a poorer one. This thesis shows, therefore, that P. aculeata and its array of genotypes in South Africa could be effectively controlled by C. schaffneri, as it has the potential to suitably utilise and impact the different genotypes of the weed in South Africa with neither any demonstrable preference nor local adaptation for the native genotypes. Consequently, the use of C. schaffneri, as a biological control agent in the weed biological control programme of P. aculeata remains promising, as the agent is insensitive to the intraspecific variation of the invasive host plants.
- Full Text:
- Date Issued: 2019
- Authors: Egbon, Ikponmwosa Nathaniel
- Date: 2019
- Subjects: Insects and biological pest control agents -- South Africa , Pereskia -- Biological control -- South Africa , Cactus -- Biological control -- South Africa , Coreida-- South Africa , Invasive plants -- Biological control -- South Africa , Catorhintha schaffneri
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68250 , vital:29223
- Description: Plant species moved beyond their natural ranges may be liberated into enemy-free spaces, where they increase resource allocation to fitness, rather than defence against natural enemies, and become invasive as suggested by the Evolution of Increased Competitive Ability (EICA) Hypothesis. Several cacti are notable invaders and are targeted for biological control. The leafy cactus, Pereskia aculeata Miller, introduced into South Africa from South America, has become a target for biological control after becoming invasive. The absence of natural enemies of P. aculeata in the introduced range may be the reason for its invasiveness. This thesis seeks to investigate the role of the evolution of increased competitive ability (enemy release) as the probable driver of P. aculeata’s success, and ascertain how the plant’s intraspecific variation influences the impact, fitness of, and preference by its biological control agent, Catorhintha schaffneri Brailovsky and Garcia (Coreidae), in South Africa. Enemy release and evolution of traits in P. aculeata were examined by quantifying plant growth parameters of fifteen genotypes of P. aculeata from both the native and invaded distribution of the plant. Ten genotypes of P. aculeata were used in testing the effect of agent herbivory (impact and damage) under similar conditions. These studies indicated that most invaded-range genotypes were more vigorous than the native genotypes. Rapid growth may account for the quick access of invasive genotypes of P. aculeata to tree canopies. Catorhintha schaffneri damage varied between genotypes but differences in the damage and impact from the agent could not be explained by whether the plant originated in the introduced or native distribution. In sum, while the growth of the invasive genotypes largely conforms to the EICA hypothesis, the impact of C. schaffneri did not support the hypothesis. The influence of host variation in P. aculeata on the fitness of C. schaffneri within the context of local adaptation to plant genotypes from different localities was tested using agent survival, stage-specific and total developmental time, and the extent of damage to ten host genotypes. Maw’s Host Suitability Index (HIS) and Dobie’s Susceptibility Index (DSI) showed the preference by and performance of C. schaffneri on the different genotypes of the plant. Catorhintha schaffneri survived to the adult stage on 70% of genotypes tested. Evidence consistent with the assumption that C. schaffneri would be fitter on the native genotypes than the invasive genotypes due to local adaptation was not found. In addition, there was no evidence in support of fitter agents on the invasive genotypes than on the native genotypes as proposed by EICA hypothesis. Catorhintha schaffneri developed equally well on the invasive genotypes of P. aculeata as on the native genotypes. To establish whether host variation would affect diet selection by C. schaffneri, both nymphs and adults were examined in paired-choice and multiple-choice trials. The nymphs and adults chose their hosts regardless of host genotype differences. The agent may be good at selecting good succulent shoots from bad shoots, but is incapable of distinguishing a good host genotype from a poorer one. This thesis shows, therefore, that P. aculeata and its array of genotypes in South Africa could be effectively controlled by C. schaffneri, as it has the potential to suitably utilise and impact the different genotypes of the weed in South Africa with neither any demonstrable preference nor local adaptation for the native genotypes. Consequently, the use of C. schaffneri, as a biological control agent in the weed biological control programme of P. aculeata remains promising, as the agent is insensitive to the intraspecific variation of the invasive host plants.
- Full Text:
- Date Issued: 2019
Sulphide textures and compositions associated with the hydrothermal/magmatic system of the Twangiza gold deposit (South Kivu, DRC)
- Authors: Busane, Emmanuel Aganze
- Date: 2019
- Subjects: Gold mines and mining -- Congo (Democratic Republic) , Geology -- Congo (Democratic Republic) , Hydrothermal alteration -- Congo (Democratic Republic) , Sulphide minerals -- Congo (Democratic Republic) , Gold ores -- Geology -- Congo (Democratic Republic) , Geochemistry -- Congo (Democratic Republic) , Twangiza Mine (Congo (Democratic Republic))
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76588 , vital:30610
- Description: Twangiza mine is a gold deposit situated in the eastern Democratic Republic of Congo. The rock types at the Twangiza Mine consist of black shale, including carbonaceous mudstone and thin intercalated layers of siltstone, and feldspar-rich granitoid intrusive sills, referred to as albitite, folded into a major antiformal structure. The gold mineralization at the mine is commonly found associated with sulphides. The sulphide textures and compositions of mineralized and unmineralized samples of black shales, albitite sills and hydrothermal veins in the mine are considered for the understanding of the spatial association of gold with sulphides and gold mineralization history of the mine. The sulphides within the Twangiza mine consist of pyrite, arsenopyrite, pyrrhotite, chalcopyrite and rare cobaltite. The primary pyrite texture occurs in unmineralized black shale and is interpreted to be diagenetic. It consists of fine-grained anhedral pyrite crystals aggregating into spherical nodules and formed in replacement of organic material during the diagenesis process. The secondary pyrite textures resulted from the hydrothermal fluids activity and include (i) aggregates of annealed anhedral crystals into sulphide-rich lenses; (ii) elongated anhedral pyrite in the form of short stringers; (iii) fine-grained subhedral to euhedral pyrite randomly distributed within the rock matrix; (iv) euhedral zoned pyrite crystals occurring within veins; (v) aggregations of fine-grained anhedral pyrite, locally distributed in the matrix; (vi) abundant dissemination of fine-grained subhedral to anhedral pyrite crystals within the vein selvedge in the host rock; (vii) and coarse-grained massive pyrite bodies. The pyrite major elemental composition does not vary significantly in the different textures and sample types. The Fe content ranges from 44.57 to 46.40 wt. %, and the S content ranges from 53.75 to 55.25 wt. %. Pyrite from mineralized black shale and hydrothermal veins contains relatively higher concentrations of As (~ 1 wt. %) than pyrite from other sample types. The arsenopyrite commonly occurs as fine-grained anhedral crystals as inclusions within pyrite, medium-grained crystal intergrowing with pyrite and/or as coarse-grained massive arsenopyrite bodies in the massive sulphide veins. The arsenopyrite composition is uniform in all textural and sample type with Fe content ranging from 33.44 to 35.20 wt. %, S content ranging from 21.13 to 22.55 wt. % and As content ranging from 42.20 to 43.97 wt. %. In mineralized black shale and unmineralized black shale, the arsenopyrite shows, however, minor concentrations of Ni with 0.39 and 0.70 wt. % respectively. The pyrrhotite occurs as fine-grained anhedral patchy crystals randomly distributed within the rock matrix of unmineralized black shale and unmineralized granitoid, and / or as inclusions within pyrite in mineralized granitoid. The pyrrhotite shows a uniform composition in all samples and textural types, though minor concentrations of Ni (2.06 wt. %) content are reported in unmineralized granitoid. Chalcopyrite occurs as fine-grained crystals in inclusions within pyrite; and cobaltite occurs as rare fine-grained anhedral crystals occasionally disseminated in the albitite sill matrix. The chalcopyrite composition does not vary considerably in all sample and textural types, and cobaltite shows minor concentrations of Ni (4.55 wt. %) and Fe (3.45 wt. %). Native gold grains are commonly found associated with the secondary pyrite texture especially within the sulphide-rich lenses and in the massive sulphide veins, and are almost pure with ~97 wt. %. A Na-rich hydrothermal fluid from low-grade metamorphism associated with the E-W compressive tectonic event, which caused formation of the antiform structure which control the mineralization in the deposit area, led to the albitization of the deposit rocks and specially the alteration of the granitic assemblage to form albitite, and the deposition of aggregates of fine-grained anhedral crystals and growth and annealing of pyrite in sulphide-rich lenses. Afterward, the CO2-rich hydrothermal fluids influx circulated through reactivated structures, including quartz veins, and led to the precipitation of dolomite, ankerite, siderite and magnesite. They also led to the precipitation of pyrite of secondary textures as well as arsenopyrite, chalcopyrite and formation of pyrrhotite from the desulphurization of early pyrite. The CO2-rich hydrothermal fluids probably leached gold and other trace elements such as As, Co, etc. from the sedimentary host rocks and deposited them into suitable traps, such as the sulphide-rich lenses and massive sulphide bodies, preferably within the hinge zone of anticline axis constituting a hydrothermal fluid pathway.
- Full Text:
- Date Issued: 2019
- Authors: Busane, Emmanuel Aganze
- Date: 2019
- Subjects: Gold mines and mining -- Congo (Democratic Republic) , Geology -- Congo (Democratic Republic) , Hydrothermal alteration -- Congo (Democratic Republic) , Sulphide minerals -- Congo (Democratic Republic) , Gold ores -- Geology -- Congo (Democratic Republic) , Geochemistry -- Congo (Democratic Republic) , Twangiza Mine (Congo (Democratic Republic))
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76588 , vital:30610
- Description: Twangiza mine is a gold deposit situated in the eastern Democratic Republic of Congo. The rock types at the Twangiza Mine consist of black shale, including carbonaceous mudstone and thin intercalated layers of siltstone, and feldspar-rich granitoid intrusive sills, referred to as albitite, folded into a major antiformal structure. The gold mineralization at the mine is commonly found associated with sulphides. The sulphide textures and compositions of mineralized and unmineralized samples of black shales, albitite sills and hydrothermal veins in the mine are considered for the understanding of the spatial association of gold with sulphides and gold mineralization history of the mine. The sulphides within the Twangiza mine consist of pyrite, arsenopyrite, pyrrhotite, chalcopyrite and rare cobaltite. The primary pyrite texture occurs in unmineralized black shale and is interpreted to be diagenetic. It consists of fine-grained anhedral pyrite crystals aggregating into spherical nodules and formed in replacement of organic material during the diagenesis process. The secondary pyrite textures resulted from the hydrothermal fluids activity and include (i) aggregates of annealed anhedral crystals into sulphide-rich lenses; (ii) elongated anhedral pyrite in the form of short stringers; (iii) fine-grained subhedral to euhedral pyrite randomly distributed within the rock matrix; (iv) euhedral zoned pyrite crystals occurring within veins; (v) aggregations of fine-grained anhedral pyrite, locally distributed in the matrix; (vi) abundant dissemination of fine-grained subhedral to anhedral pyrite crystals within the vein selvedge in the host rock; (vii) and coarse-grained massive pyrite bodies. The pyrite major elemental composition does not vary significantly in the different textures and sample types. The Fe content ranges from 44.57 to 46.40 wt. %, and the S content ranges from 53.75 to 55.25 wt. %. Pyrite from mineralized black shale and hydrothermal veins contains relatively higher concentrations of As (~ 1 wt. %) than pyrite from other sample types. The arsenopyrite commonly occurs as fine-grained anhedral crystals as inclusions within pyrite, medium-grained crystal intergrowing with pyrite and/or as coarse-grained massive arsenopyrite bodies in the massive sulphide veins. The arsenopyrite composition is uniform in all textural and sample type with Fe content ranging from 33.44 to 35.20 wt. %, S content ranging from 21.13 to 22.55 wt. % and As content ranging from 42.20 to 43.97 wt. %. In mineralized black shale and unmineralized black shale, the arsenopyrite shows, however, minor concentrations of Ni with 0.39 and 0.70 wt. % respectively. The pyrrhotite occurs as fine-grained anhedral patchy crystals randomly distributed within the rock matrix of unmineralized black shale and unmineralized granitoid, and / or as inclusions within pyrite in mineralized granitoid. The pyrrhotite shows a uniform composition in all samples and textural types, though minor concentrations of Ni (2.06 wt. %) content are reported in unmineralized granitoid. Chalcopyrite occurs as fine-grained crystals in inclusions within pyrite; and cobaltite occurs as rare fine-grained anhedral crystals occasionally disseminated in the albitite sill matrix. The chalcopyrite composition does not vary considerably in all sample and textural types, and cobaltite shows minor concentrations of Ni (4.55 wt. %) and Fe (3.45 wt. %). Native gold grains are commonly found associated with the secondary pyrite texture especially within the sulphide-rich lenses and in the massive sulphide veins, and are almost pure with ~97 wt. %. A Na-rich hydrothermal fluid from low-grade metamorphism associated with the E-W compressive tectonic event, which caused formation of the antiform structure which control the mineralization in the deposit area, led to the albitization of the deposit rocks and specially the alteration of the granitic assemblage to form albitite, and the deposition of aggregates of fine-grained anhedral crystals and growth and annealing of pyrite in sulphide-rich lenses. Afterward, the CO2-rich hydrothermal fluids influx circulated through reactivated structures, including quartz veins, and led to the precipitation of dolomite, ankerite, siderite and magnesite. They also led to the precipitation of pyrite of secondary textures as well as arsenopyrite, chalcopyrite and formation of pyrrhotite from the desulphurization of early pyrite. The CO2-rich hydrothermal fluids probably leached gold and other trace elements such as As, Co, etc. from the sedimentary host rocks and deposited them into suitable traps, such as the sulphide-rich lenses and massive sulphide bodies, preferably within the hinge zone of anticline axis constituting a hydrothermal fluid pathway.
- Full Text:
- Date Issued: 2019
Post-release evaluation of Megamelus scutellaris Berg. (hemiptera: delphacidae): a biological control agent of water hyacinth Eichhornia crassipes (Mart.) Solms-Laub (Pontederiaceae) in South Africa
- Authors: Miller, Benjamin Erich
- Date: 2019
- Subjects: Megamelus scutellaris Berg. , Delphacidae , Noxious weeds -- Biological control -- South Africa , Aquatic weeds -- Biological control -- South Africa , Water hyacinth -- Biological control -- South Africa , Biological pest control agents
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92330 , vital:30710
- Description: Water hyacinth, Eichhornia crassipes (Mart.) Solms-Laub. (Pontederiaceae) is a free-floating aquatic macrophyte from South America that was introduced to South Africa in the 1900s for its attractive ornamental flowers. The plant was classified as a serious invader in the country in the 1970s, eventually becoming the worst invasive aquatic plant in South Africa. Biological control is widely regarded as the most effective method of managing water hyacinth, as it is ecologically safe, cost-effective, and self-sustaining. To date, nine biological control agents have been released in South Africa against water hyacinth, including eight arthropods and a pathogen. Due to the cumulative effects of highly eutrophic waterbodies, which mitigate the damage caused by biological control, and the cold winters which inhibit the rate of biological control agent population build up, South Africa currently has more biological control agents released on water hyacinth than anywhere else in the world. The need for a cold-tolerant agent that can reproduce and develop quickly, while still being damaging to water hyacinth in eutrophic systems, led to the introduction of the most recently released water hyacinth biological control agent, the planthopper Megamelus scutellaris Berg (Hemiptera: Delphacidae), which was initially collected from Argentina. This thesis formed the first post-release evaluation of M. scutellaris since its release in South Africa in 2013. It included a greenhouse experiment to measure the agent’s feeding damage in relation to different nutrient levels and stocking rates, as well as a field component to evaluate both the post-winter recovery of M. scutellaris, and a nationwide survey to measure the establishment of the agent around the country in relation to climate, water quality, and plant health. In the greenhouse experiment, the feeding damage was quantified using measurements of plant growth parameters and chlorophyll fluorometry. It was found that, like other biological control agents of water hyacinth, M. scutellaris was most damaging when released in high numbers on plants grown at medium nutrient levels, and less effective on plants grown at elevated nutrient levels. A water hyacinth infestation on the Kubusi River was selected for the evaluation of the post-winter recovery of M. scutellaris. The Kubusi River is both the first site where M. scutellaris was released, and the coldest site where water hyacinth biological control agents have established successfully in South Africa. Monthly visits tracking seasonal plant health characteristics and agent population densities indicated that the populations of M. scutellaris were impacted most significantly by the season. Low temperatures led to the water hyacinth plants being of poor quality during the winter, which had a subsequent negative effect on the agent populations. The agents could only fully recover by late summer, which meant that the plants were without any significant biological control through the initial phases of the growing season, when they were most vulnerable, and a significant lag-phase occurred between the recovery of the plants and the recovery of the agent population after the winter bottleneck. A survey of all sites where M. scutellaris had been released in South Africa yielded 16 sites where the agents had successfully established, having survived at least one full winter. Among these sites were four sites where the agents were found without them having been released, indicating that they can disperse unaided to new sites. The temperature was a major factor responsible for the success or failure of establishment, with very few agents surviving in the hot areas of South Africa or in areas with a high frost incidence. The density of M. scutellaris was higher in nutrient-rich water, and on plants with more leaves, suggesting that the quality of the plants also contributed to establishment. The results of this thesis showed that M. scutellaris is able to establish successfully in South Africa, and that the agents are capable of causing significant damage to water hyacinth, making it a promising addition to the biological control programme. Novel methods of measuring subtle insect feeding damage in plants and quantifying agent populations are also discussed, along with suggestions for the future implementation of M. scutellaris in South Africa.
- Full Text:
- Date Issued: 2019
- Authors: Miller, Benjamin Erich
- Date: 2019
- Subjects: Megamelus scutellaris Berg. , Delphacidae , Noxious weeds -- Biological control -- South Africa , Aquatic weeds -- Biological control -- South Africa , Water hyacinth -- Biological control -- South Africa , Biological pest control agents
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92330 , vital:30710
- Description: Water hyacinth, Eichhornia crassipes (Mart.) Solms-Laub. (Pontederiaceae) is a free-floating aquatic macrophyte from South America that was introduced to South Africa in the 1900s for its attractive ornamental flowers. The plant was classified as a serious invader in the country in the 1970s, eventually becoming the worst invasive aquatic plant in South Africa. Biological control is widely regarded as the most effective method of managing water hyacinth, as it is ecologically safe, cost-effective, and self-sustaining. To date, nine biological control agents have been released in South Africa against water hyacinth, including eight arthropods and a pathogen. Due to the cumulative effects of highly eutrophic waterbodies, which mitigate the damage caused by biological control, and the cold winters which inhibit the rate of biological control agent population build up, South Africa currently has more biological control agents released on water hyacinth than anywhere else in the world. The need for a cold-tolerant agent that can reproduce and develop quickly, while still being damaging to water hyacinth in eutrophic systems, led to the introduction of the most recently released water hyacinth biological control agent, the planthopper Megamelus scutellaris Berg (Hemiptera: Delphacidae), which was initially collected from Argentina. This thesis formed the first post-release evaluation of M. scutellaris since its release in South Africa in 2013. It included a greenhouse experiment to measure the agent’s feeding damage in relation to different nutrient levels and stocking rates, as well as a field component to evaluate both the post-winter recovery of M. scutellaris, and a nationwide survey to measure the establishment of the agent around the country in relation to climate, water quality, and plant health. In the greenhouse experiment, the feeding damage was quantified using measurements of plant growth parameters and chlorophyll fluorometry. It was found that, like other biological control agents of water hyacinth, M. scutellaris was most damaging when released in high numbers on plants grown at medium nutrient levels, and less effective on plants grown at elevated nutrient levels. A water hyacinth infestation on the Kubusi River was selected for the evaluation of the post-winter recovery of M. scutellaris. The Kubusi River is both the first site where M. scutellaris was released, and the coldest site where water hyacinth biological control agents have established successfully in South Africa. Monthly visits tracking seasonal plant health characteristics and agent population densities indicated that the populations of M. scutellaris were impacted most significantly by the season. Low temperatures led to the water hyacinth plants being of poor quality during the winter, which had a subsequent negative effect on the agent populations. The agents could only fully recover by late summer, which meant that the plants were without any significant biological control through the initial phases of the growing season, when they were most vulnerable, and a significant lag-phase occurred between the recovery of the plants and the recovery of the agent population after the winter bottleneck. A survey of all sites where M. scutellaris had been released in South Africa yielded 16 sites where the agents had successfully established, having survived at least one full winter. Among these sites were four sites where the agents were found without them having been released, indicating that they can disperse unaided to new sites. The temperature was a major factor responsible for the success or failure of establishment, with very few agents surviving in the hot areas of South Africa or in areas with a high frost incidence. The density of M. scutellaris was higher in nutrient-rich water, and on plants with more leaves, suggesting that the quality of the plants also contributed to establishment. The results of this thesis showed that M. scutellaris is able to establish successfully in South Africa, and that the agents are capable of causing significant damage to water hyacinth, making it a promising addition to the biological control programme. Novel methods of measuring subtle insect feeding damage in plants and quantifying agent populations are also discussed, along with suggestions for the future implementation of M. scutellaris in South Africa.
- Full Text:
- Date Issued: 2019
‘Jujutech’: exploring cultural and epistemological hybridity in African science fiction
- Authors: Stier, Jordan Daniel
- Date: 2019
- Subjects: Science fiction, African -- History and criticism , Tutuola, Amos. The palm-wine drunkard , Mkize, Loyiso, 1987- .Kwezi , Black Panther (Comic book) , Dila, Dilman, 1977-. A killing in the sun , Superheroes, Black , Mbvundula, Ekari. Montague's last
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96908 , vital:31346
- Description: This thesis aims to respond to the rise in the production of science fiction in Africa over the last decade, and to show how what I describe as the juju orientation of many of these works does not disqualify them from the genre of science fiction. Rather, I advocate for the recognition of juju ontologies as genuine sources of knowledge about the world, which have been overlooked by the globally dominant scientism that has informed science fiction theorisation to date. In my introduction I outline the theoretical frameworks of juju, science fiction and epistemology with which the thesis is in communication. In my second chapter I re-read Amos Tutuola’s novel The Palm-Wine Drinkard, showing the inherently science fictional structure of the juju-based storytelling that characterises colonial and pre-colonial African literature, as well as the essentiality of science fictional modes to Tutuola’s own prose. My third chapter considers Ian MacDonald’s theorisation of a jujutech aesthetic in African science fiction, wherein the speculations of the genres are rooted in both technoscientific and juju ontologies simultaneously. I account for the role this literary aesthetic plays in Ekari Mbvundula’s “Montague’s Last” to blur the divisions of worldly knowledge enforced by global epistemological inequalities, before showing how Dilman Dila’s A Killing in the Sun presents a critically frontier African epistemology in literary practice, and the value thereof. My fourth chapter considers the role of popular culture and consumption, and how the global literary industry resists juju-based texts. I conclude that juju-based nova and the jujutech aesthetic are not only essentially science fictional literary modes, but important players in science fiction’s role in being epistemologically productive in the future.
- Full Text:
- Date Issued: 2019
- Authors: Stier, Jordan Daniel
- Date: 2019
- Subjects: Science fiction, African -- History and criticism , Tutuola, Amos. The palm-wine drunkard , Mkize, Loyiso, 1987- .Kwezi , Black Panther (Comic book) , Dila, Dilman, 1977-. A killing in the sun , Superheroes, Black , Mbvundula, Ekari. Montague's last
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96908 , vital:31346
- Description: This thesis aims to respond to the rise in the production of science fiction in Africa over the last decade, and to show how what I describe as the juju orientation of many of these works does not disqualify them from the genre of science fiction. Rather, I advocate for the recognition of juju ontologies as genuine sources of knowledge about the world, which have been overlooked by the globally dominant scientism that has informed science fiction theorisation to date. In my introduction I outline the theoretical frameworks of juju, science fiction and epistemology with which the thesis is in communication. In my second chapter I re-read Amos Tutuola’s novel The Palm-Wine Drinkard, showing the inherently science fictional structure of the juju-based storytelling that characterises colonial and pre-colonial African literature, as well as the essentiality of science fictional modes to Tutuola’s own prose. My third chapter considers Ian MacDonald’s theorisation of a jujutech aesthetic in African science fiction, wherein the speculations of the genres are rooted in both technoscientific and juju ontologies simultaneously. I account for the role this literary aesthetic plays in Ekari Mbvundula’s “Montague’s Last” to blur the divisions of worldly knowledge enforced by global epistemological inequalities, before showing how Dilman Dila’s A Killing in the Sun presents a critically frontier African epistemology in literary practice, and the value thereof. My fourth chapter considers the role of popular culture and consumption, and how the global literary industry resists juju-based texts. I conclude that juju-based nova and the jujutech aesthetic are not only essentially science fictional literary modes, but important players in science fiction’s role in being epistemologically productive in the future.
- Full Text:
- Date Issued: 2019
A pilot wide-field VLBI survey of the GOODS-North field
- Authors: Akoto-Danso, Alexander
- Date: 2019
- Subjects: Radio astronomy , Very long baseline interferometry , Radio interometers , Imaging systems in astronomy , Hubble Space Telescope (Spacecraft) -- Observations
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72296 , vital:30027
- Description: Very Long Baseline Interferometry (VLBI) has significant advantages in disentangling active galactic nuclei (AGN) from star formation, particularly at intermediate to high-redshift due to its high angular resolution and insensitivity to dust. Surveys using VLBI arrays are only just becoming practical over wide areas with numerous developments and innovations (such as multi-phase centre techniques) in observation and data analysis techniques. However, fully automated pipelines for VLBI data analysis are based on old software packages and are unable to incorporate new calibration and imaging algorithms. In this work, the researcher developed a pipeline for VLBI data analysis which integrates a recent wide-field imaging algorithm, RFI excision, and a purpose-built source finding algorithm specifically developed for the 64kx64k wide-field VLBI images. The researcher used this novel pipeline to process 6% (~ 9 arcmin2 of the total 160 arcmin2) of the data from the CANDELS GOODS- North extragalactic field at 1.6 GHz. The milli-arcsec scale images have an average rms of a ~ 10 uJy/beam. Forty four (44) candidate sources were detected, most of which are at sub-mJy flux densities, having brightness temperatures and luminosities of >5x105 K and >6x1021 W Hz-1 respectively. This work demonstrates that automated post-processing pipelines for wide-field, uniform sensitivity VLBI surveys are feasible and indeed made more efficient with new software, wide-field imaging algorithms and more purpose-built source- finders. This broadens the discovery space for future wide-field surveys with upcoming arrays such as the African VLBI Network (AVN), MeerKAT and the Square Kilometre Array (SKA).
- Full Text:
- Date Issued: 2019
- Authors: Akoto-Danso, Alexander
- Date: 2019
- Subjects: Radio astronomy , Very long baseline interferometry , Radio interometers , Imaging systems in astronomy , Hubble Space Telescope (Spacecraft) -- Observations
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72296 , vital:30027
- Description: Very Long Baseline Interferometry (VLBI) has significant advantages in disentangling active galactic nuclei (AGN) from star formation, particularly at intermediate to high-redshift due to its high angular resolution and insensitivity to dust. Surveys using VLBI arrays are only just becoming practical over wide areas with numerous developments and innovations (such as multi-phase centre techniques) in observation and data analysis techniques. However, fully automated pipelines for VLBI data analysis are based on old software packages and are unable to incorporate new calibration and imaging algorithms. In this work, the researcher developed a pipeline for VLBI data analysis which integrates a recent wide-field imaging algorithm, RFI excision, and a purpose-built source finding algorithm specifically developed for the 64kx64k wide-field VLBI images. The researcher used this novel pipeline to process 6% (~ 9 arcmin2 of the total 160 arcmin2) of the data from the CANDELS GOODS- North extragalactic field at 1.6 GHz. The milli-arcsec scale images have an average rms of a ~ 10 uJy/beam. Forty four (44) candidate sources were detected, most of which are at sub-mJy flux densities, having brightness temperatures and luminosities of >5x105 K and >6x1021 W Hz-1 respectively. This work demonstrates that automated post-processing pipelines for wide-field, uniform sensitivity VLBI surveys are feasible and indeed made more efficient with new software, wide-field imaging algorithms and more purpose-built source- finders. This broadens the discovery space for future wide-field surveys with upcoming arrays such as the African VLBI Network (AVN), MeerKAT and the Square Kilometre Array (SKA).
- Full Text:
- Date Issued: 2019
Using captive seabirds to assess knowledge gaps in stable isotope analysis of diets
- Authors: Micklem, Isabel Andrea
- Date: 2019
- Subjects: Stable isotopes -- Analysis African penguin -- South Africa Breeding
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65101 , vital:28686
- Description: Stable isotope (SI) ratios of carbon (δ13C) and nitrogen (δ15N) are now widely used as biomarkers in ecological studies to provide information about food web structuring. However, understanding trophic relationships using SI analysis requires not only knowledge of SI values of predator and prey, but also accurate discrimination factors (DFs), which can differ among species and by physiological state. This thesis examined three questions using captive birds from the South African Foundation for the Conservation of Coastal Birds (SANCCOB). First, the effects of ontogeny on δ13C and δ15N ratios of African penguins (Spheniscus demersus) were assessed. Blood samples were collected from penguins in four age classes (P3 chicks, blues, juveniles and adults) concurrently with their diet (sardine (Sardinops sagax) and formula). Second, to assess the influence of breeding physiology on SI ratios, the blood of ten breeding pairs of penguins was sampled over a five-month period from June to October 2016. Following laying, each pair was categorised into one of three (four for whole blood) egg production phases (initial yolk deposition, rapid yolk deposition and post-laying) and their influences on SI ratios were tested. Third, species differences in DFs were evaluated for African penguins, kelp and Hartlaub’s gulls (Larus dominicanus and L. hartlaubii), greater crested terns (Thalasseus bergii) and Cape cormorants (Phalacrocorax capensis). Flying birds were mostly fed sardine with a small but unknown amount of sardinella (Sardinella aurita), DFs were therefore estimated for a 50:50 sardine:sardinella diet, a 75:25 sardine:sardinella diet and a 100% sardine diet for each flying bird species. The DFs were assessed for the whole blood (WB), red blood cells (RBC), plasma (PL) and delipidated plasma of the penguins, and only WB for the flying birds as well as flesh, whole fish, delipidated flesh and delipidated whole fish for fish species, and for formula. Results indicated that age influenced both the δ13C and δ15N of WB, only the δ15N of RBC and the δ13C of delipidated PL. The assessment of breeding physiology yielded a significant interaction between the effects of egg production phase and sex on the δ13C of WB; females had significantly lower δ13C in the rapid yolk deposition phase than the other two phases and all males. The δ13C of PL was affected only by sex, with females having a significantly lower δ13C value than males. Neither physiological state nor sex influenced the other blood components. Differences were found among the three DFs in the non-penguin species, but not for all consumer – prey tissue combinations. There were also significant differences among species with a DF calculated from a diet with the most probable prey proportions eaten. Depending on the combination of consumer and prey tissue used to calculate the DF, a different conclusion regarding trophic information can be reached. A literature review updated with the present data showed that no general pattern or grouping of similar species with regards to DF values could be drawn, highlighting the importance of determining species- and tissue-specific DFs. Thus age, egg production, tissue and species all influenced the SI values of bird blood and therefore their DFs. Not all physiological conditions affect all blood components in the same way, making different components more or less sensitive to physiological influences. Though their influence is at a small enough scale that it is unlikely to hamper correct conclusion in ecological studies, it is crucial that these factors are considered when using SI analysis (SIA). When uncertainties exist for some coefficients in wild studies, SIA should therefore be combined to other dietary techniques to determine the food web structure as best as possible.
- Full Text:
- Date Issued: 2019
- Authors: Micklem, Isabel Andrea
- Date: 2019
- Subjects: Stable isotopes -- Analysis African penguin -- South Africa Breeding
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65101 , vital:28686
- Description: Stable isotope (SI) ratios of carbon (δ13C) and nitrogen (δ15N) are now widely used as biomarkers in ecological studies to provide information about food web structuring. However, understanding trophic relationships using SI analysis requires not only knowledge of SI values of predator and prey, but also accurate discrimination factors (DFs), which can differ among species and by physiological state. This thesis examined three questions using captive birds from the South African Foundation for the Conservation of Coastal Birds (SANCCOB). First, the effects of ontogeny on δ13C and δ15N ratios of African penguins (Spheniscus demersus) were assessed. Blood samples were collected from penguins in four age classes (P3 chicks, blues, juveniles and adults) concurrently with their diet (sardine (Sardinops sagax) and formula). Second, to assess the influence of breeding physiology on SI ratios, the blood of ten breeding pairs of penguins was sampled over a five-month period from June to October 2016. Following laying, each pair was categorised into one of three (four for whole blood) egg production phases (initial yolk deposition, rapid yolk deposition and post-laying) and their influences on SI ratios were tested. Third, species differences in DFs were evaluated for African penguins, kelp and Hartlaub’s gulls (Larus dominicanus and L. hartlaubii), greater crested terns (Thalasseus bergii) and Cape cormorants (Phalacrocorax capensis). Flying birds were mostly fed sardine with a small but unknown amount of sardinella (Sardinella aurita), DFs were therefore estimated for a 50:50 sardine:sardinella diet, a 75:25 sardine:sardinella diet and a 100% sardine diet for each flying bird species. The DFs were assessed for the whole blood (WB), red blood cells (RBC), plasma (PL) and delipidated plasma of the penguins, and only WB for the flying birds as well as flesh, whole fish, delipidated flesh and delipidated whole fish for fish species, and for formula. Results indicated that age influenced both the δ13C and δ15N of WB, only the δ15N of RBC and the δ13C of delipidated PL. The assessment of breeding physiology yielded a significant interaction between the effects of egg production phase and sex on the δ13C of WB; females had significantly lower δ13C in the rapid yolk deposition phase than the other two phases and all males. The δ13C of PL was affected only by sex, with females having a significantly lower δ13C value than males. Neither physiological state nor sex influenced the other blood components. Differences were found among the three DFs in the non-penguin species, but not for all consumer – prey tissue combinations. There were also significant differences among species with a DF calculated from a diet with the most probable prey proportions eaten. Depending on the combination of consumer and prey tissue used to calculate the DF, a different conclusion regarding trophic information can be reached. A literature review updated with the present data showed that no general pattern or grouping of similar species with regards to DF values could be drawn, highlighting the importance of determining species- and tissue-specific DFs. Thus age, egg production, tissue and species all influenced the SI values of bird blood and therefore their DFs. Not all physiological conditions affect all blood components in the same way, making different components more or less sensitive to physiological influences. Though their influence is at a small enough scale that it is unlikely to hamper correct conclusion in ecological studies, it is crucial that these factors are considered when using SI analysis (SIA). When uncertainties exist for some coefficients in wild studies, SIA should therefore be combined to other dietary techniques to determine the food web structure as best as possible.
- Full Text:
- Date Issued: 2019
The role of agricultural support programmes on the livelihoods of smallholder maize farmers in Lesotho: asset utilisation, productivity and perceptions
- Authors: Mohlahatsa, Taole
- Date: 2019
- Subjects: Agriculture and state -- Lesotho , Agriculture -- Economic aspects -- Lesotho , Farms, Small -- Government policy -- Lesotho , Farms, Small -- Lesotho , Agricultural assistance -- Lesotho , Rural development -- Lesotho
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/71580 , vital:29914
- Description: The agricultural sector is widely considered an important contributor to economic development in least developed countries. It plays an important role in Lesotho and has been the backbone of rural activities and the prime employer of Basotho citizens. Smallholder farming is recognised by the government of Lesotho as a vehicle for addressing food security and poverty reduction. Maize is the principal staple crop produced by about 90 percent of farmers in Lesotho and it constitutes about 80 percent of the Basotho diet. Maize production is highly affected by climate change and is characterised by fluctuating yields because of erratic rainfall. In addition to unfavorable climate change, smallholder farmers in Lesotho experience challenges such as lack of farming inputs, limited access to markets and limited financial capital. These constraints confine them to a life of subsistence farming with low production and increased incidences of poverty. The government of Lesotho has intervened in the smallholder agricultural sector to stimulate production and productivity by introducing some agricultural programmes such as (i) the National Fertiliser and Input subsidy, (ii) the Smallholder Agricultural Development Programme, (iii) the National Block Farming, and (iv) the Integrated Watershed Management Programme. However, despite such government interventions, production in the smallholder agricultural sector continues to face recurring constraints. Studies on the National Block Farming Programme have showed that the programme has had limited impact on the livelihoods of smallholder farmers. Furthermore, farmers believe the Integrated Watershed Management Programme has a biased selection criteria as selection of areas is influenced by politicians who favour areas where they have a large political following and marginilise other areas. These concerns have also led to low participation rates in such programmes as wealthier, large scale farmers capture most of the benefits of government programmes. Disproportionate benefits of agricultural programmes to smallholder farmers imply that they continue to face the same constraints in production and have to find alternative ways of maintaining production and selling excess produce to sustain their livelihoods. The main goal of this research is therefore to study the livelihoods of smallholder maize farmers in Lesotho and how agricultural support programmes influence their production of maize. The study adopted a pragmatic mixed methods approach with a qualitative dominant sequential design. Accordingly, both quantitative and qualitative data was used to address the research goal. Quantitative data collected from the Lesotho Bureau of Statistics and the World Bank was used for trend analysis on maize productivity, temperature and rainfall over the period 1980-2016. Qualitative primary data was collected by conducting focus group discussions with smallholder maize farmers and key stakeholder interviews using the sustainable livelihood framework as a conceptual guide. The study comprised of a total of 85 research participants consisting of 75 smallholder maize farmers and 10 key stakeholders. Farmers were selected from 10 key maize producing areas in Leribe and Mafeteng districts in Leribe. Results revealed fluctuating maize productivity and productivity growth rates where such fluctuations are caused by government intervention and natural calamities in the form of erratic rains and dry spells. Droughts and late arrival of subsidised inputs are the chief constraints to maize production. In relation to livelihood assets, human and social assets are the more available assets relative to other assets (financial, natural and physical) of the sustainable livelihood framework. Furthermore, the National Fertiliser and Input subsidy Programme and the Smallholder Agricultural Development Programme are the most beneficial programmes to farmers livelihoods as they increase the accessibility of limited livelihood assets and therefore allowing farmers to achieve their livelihood goals. In contrast, the National Block Farming and the Integrated Watershed Management Programme are the least beneficial programmes to farmers’ livelihoods and are biased in their geographical targeting criteria. The study recommends that the government revises all selected support programmes in this study in areas warranting improvements so as to fairly and efficiently allocate resources that meet the needs of farmers. The study also recommends that farmers put more effort in adopting new technologies and strategies to improve production of maize in areas where government intervention has failed.
- Full Text:
- Date Issued: 2019
- Authors: Mohlahatsa, Taole
- Date: 2019
- Subjects: Agriculture and state -- Lesotho , Agriculture -- Economic aspects -- Lesotho , Farms, Small -- Government policy -- Lesotho , Farms, Small -- Lesotho , Agricultural assistance -- Lesotho , Rural development -- Lesotho
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/71580 , vital:29914
- Description: The agricultural sector is widely considered an important contributor to economic development in least developed countries. It plays an important role in Lesotho and has been the backbone of rural activities and the prime employer of Basotho citizens. Smallholder farming is recognised by the government of Lesotho as a vehicle for addressing food security and poverty reduction. Maize is the principal staple crop produced by about 90 percent of farmers in Lesotho and it constitutes about 80 percent of the Basotho diet. Maize production is highly affected by climate change and is characterised by fluctuating yields because of erratic rainfall. In addition to unfavorable climate change, smallholder farmers in Lesotho experience challenges such as lack of farming inputs, limited access to markets and limited financial capital. These constraints confine them to a life of subsistence farming with low production and increased incidences of poverty. The government of Lesotho has intervened in the smallholder agricultural sector to stimulate production and productivity by introducing some agricultural programmes such as (i) the National Fertiliser and Input subsidy, (ii) the Smallholder Agricultural Development Programme, (iii) the National Block Farming, and (iv) the Integrated Watershed Management Programme. However, despite such government interventions, production in the smallholder agricultural sector continues to face recurring constraints. Studies on the National Block Farming Programme have showed that the programme has had limited impact on the livelihoods of smallholder farmers. Furthermore, farmers believe the Integrated Watershed Management Programme has a biased selection criteria as selection of areas is influenced by politicians who favour areas where they have a large political following and marginilise other areas. These concerns have also led to low participation rates in such programmes as wealthier, large scale farmers capture most of the benefits of government programmes. Disproportionate benefits of agricultural programmes to smallholder farmers imply that they continue to face the same constraints in production and have to find alternative ways of maintaining production and selling excess produce to sustain their livelihoods. The main goal of this research is therefore to study the livelihoods of smallholder maize farmers in Lesotho and how agricultural support programmes influence their production of maize. The study adopted a pragmatic mixed methods approach with a qualitative dominant sequential design. Accordingly, both quantitative and qualitative data was used to address the research goal. Quantitative data collected from the Lesotho Bureau of Statistics and the World Bank was used for trend analysis on maize productivity, temperature and rainfall over the period 1980-2016. Qualitative primary data was collected by conducting focus group discussions with smallholder maize farmers and key stakeholder interviews using the sustainable livelihood framework as a conceptual guide. The study comprised of a total of 85 research participants consisting of 75 smallholder maize farmers and 10 key stakeholders. Farmers were selected from 10 key maize producing areas in Leribe and Mafeteng districts in Leribe. Results revealed fluctuating maize productivity and productivity growth rates where such fluctuations are caused by government intervention and natural calamities in the form of erratic rains and dry spells. Droughts and late arrival of subsidised inputs are the chief constraints to maize production. In relation to livelihood assets, human and social assets are the more available assets relative to other assets (financial, natural and physical) of the sustainable livelihood framework. Furthermore, the National Fertiliser and Input subsidy Programme and the Smallholder Agricultural Development Programme are the most beneficial programmes to farmers livelihoods as they increase the accessibility of limited livelihood assets and therefore allowing farmers to achieve their livelihood goals. In contrast, the National Block Farming and the Integrated Watershed Management Programme are the least beneficial programmes to farmers’ livelihoods and are biased in their geographical targeting criteria. The study recommends that the government revises all selected support programmes in this study in areas warranting improvements so as to fairly and efficiently allocate resources that meet the needs of farmers. The study also recommends that farmers put more effort in adopting new technologies and strategies to improve production of maize in areas where government intervention has failed.
- Full Text:
- Date Issued: 2019
Factors influencing parents’ decisions when choosing a private school
- Authors: Arendse, David
- Date: 2019
- Subjects: School choice -- South Africa -- Case studies , Competition -- South Africa , Private schools -- South Africa , Consumer behavior , VRIO framework (Valuable, Rare, Imitable and Organized) , St. Stithians College
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/92628 , vital:30738
- Description: Purpose: Consumers make decisions based on multiple factors that influence their decision-making process. These decisions can be influenced by deep personal reflection to the simple impulsive purchase done to fulfil a need or want. This research study explored the relationship between the resource-based view and the factors considered by parents when selecting a school for their child/children. The Valuable, Rare, Imitable and Organized (VRIO) framework as developed by Barney, J. (1991) outlines the framework through which an organisations resources can be assessed in terms of their potential competitive advantage. The research study was interested in understanding how an educational institution can identify and then leverage its resources to create a competitive advantage. Methodology: Each family that has one or more child enrolled at St Stithians College, which is a private school in Gauteng, South Africa, was invited to participate in the study. This represented a potential population size of 1 700 families, however a sample of 334 was used. The educational institution caters to both boys and girls from Grade R to 12 (Matric). Each family was requested to participate in the study as they had already chosen to have at least one child enrolled. A self-administered close-ended questionnaire was used as the instrument for data collection and the questionnaire was broken into two sections. Section A focused on building a profile of the respondent while section B assessed the level of influence the factors had on a parent’s decision. Section B’s questions were structured as Likert-Scale questions requiring a response between 1 and 5, with 5 being the highest influence, and 1 being the lowest. The responses to the questions were then grouped into the factors they spoke to and the average results per factor were assessed via an ANOVA table to test the null hypothesis that parents do not consider factors when choosing a school for their children. Findings: As a paper, this study set out to discover what the competitive advantage was of a private education institution in South Africa. It did so by identifying what the key factors were when parents selected the school of their choice and then analysed these findings against the resources of the given institution. The ANOVA table analysis of the responses identified that parents do consider factors and that the factor that they were most influenced by was convenience factor, represented by location of the institution and the distance to it. While there are multiple private education suppliers in South Africa, no other provider has the location that St Stithians College has, and as such, its location is its competitive advantage. Significant: This research study will expand the existing but limited competitive advantage body of knowledge in the South African education sector. South African educational institutions will be able to develop similar studies which will then assist in identifying their own competitive advantages. This can better enable education providers to entice consumers to their education services.
- Full Text:
- Date Issued: 2019
- Authors: Arendse, David
- Date: 2019
- Subjects: School choice -- South Africa -- Case studies , Competition -- South Africa , Private schools -- South Africa , Consumer behavior , VRIO framework (Valuable, Rare, Imitable and Organized) , St. Stithians College
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/92628 , vital:30738
- Description: Purpose: Consumers make decisions based on multiple factors that influence their decision-making process. These decisions can be influenced by deep personal reflection to the simple impulsive purchase done to fulfil a need or want. This research study explored the relationship between the resource-based view and the factors considered by parents when selecting a school for their child/children. The Valuable, Rare, Imitable and Organized (VRIO) framework as developed by Barney, J. (1991) outlines the framework through which an organisations resources can be assessed in terms of their potential competitive advantage. The research study was interested in understanding how an educational institution can identify and then leverage its resources to create a competitive advantage. Methodology: Each family that has one or more child enrolled at St Stithians College, which is a private school in Gauteng, South Africa, was invited to participate in the study. This represented a potential population size of 1 700 families, however a sample of 334 was used. The educational institution caters to both boys and girls from Grade R to 12 (Matric). Each family was requested to participate in the study as they had already chosen to have at least one child enrolled. A self-administered close-ended questionnaire was used as the instrument for data collection and the questionnaire was broken into two sections. Section A focused on building a profile of the respondent while section B assessed the level of influence the factors had on a parent’s decision. Section B’s questions were structured as Likert-Scale questions requiring a response between 1 and 5, with 5 being the highest influence, and 1 being the lowest. The responses to the questions were then grouped into the factors they spoke to and the average results per factor were assessed via an ANOVA table to test the null hypothesis that parents do not consider factors when choosing a school for their children. Findings: As a paper, this study set out to discover what the competitive advantage was of a private education institution in South Africa. It did so by identifying what the key factors were when parents selected the school of their choice and then analysed these findings against the resources of the given institution. The ANOVA table analysis of the responses identified that parents do consider factors and that the factor that they were most influenced by was convenience factor, represented by location of the institution and the distance to it. While there are multiple private education suppliers in South Africa, no other provider has the location that St Stithians College has, and as such, its location is its competitive advantage. Significant: This research study will expand the existing but limited competitive advantage body of knowledge in the South African education sector. South African educational institutions will be able to develop similar studies which will then assist in identifying their own competitive advantages. This can better enable education providers to entice consumers to their education services.
- Full Text:
- Date Issued: 2019