Integrated Algae Pond Systems for the Treatment of Municipal Wastewater
- Authors: Mambo, Mutsa Prudence
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5960 , http://hdl.handle.net/10962/d1021258
- Description: Integrated algae pond systems are a derivation of the Oswald designed advanced integrated wastewater ponding system, and combine the use of anaerobic and aerobic bioprocesses to effect wastewater treatment. Integrated algae pond system technology was introduced to South Africa in 1996 and a pilot plant was designed and commissioned at the Belmont Valley wastewater treatment works in Grahamstown. Previous studies showed that this system delivered a final effluent superior to most pond systems deployed in South Africa but that it was unable to meet the general standard for nutrient removal and effluent discharge. This study was initiated to re-appraise integrated algae pond systems and to assess the potential of the technology as an effective municipal sewage treatment system. And more...
- Full Text:
- Date Issued: 2016
- Authors: Mambo, Mutsa Prudence
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5960 , http://hdl.handle.net/10962/d1021258
- Description: Integrated algae pond systems are a derivation of the Oswald designed advanced integrated wastewater ponding system, and combine the use of anaerobic and aerobic bioprocesses to effect wastewater treatment. Integrated algae pond system technology was introduced to South Africa in 1996 and a pilot plant was designed and commissioned at the Belmont Valley wastewater treatment works in Grahamstown. Previous studies showed that this system delivered a final effluent superior to most pond systems deployed in South Africa but that it was unable to meet the general standard for nutrient removal and effluent discharge. This study was initiated to re-appraise integrated algae pond systems and to assess the potential of the technology as an effective municipal sewage treatment system. And more...
- Full Text:
- Date Issued: 2016
Shifting identities: An exploration of the possibilities for a syncretic Afrikaans theatre by means of three case studies – Hex (2003), Lady Anne (2007), Ekspedisies (2008)
- Authors: Gehring, Heike
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2165 , http://hdl.handle.net/10962/d1021269
- Description: This thesis investigates the possibilities for syncretic Afrikaans language theatre within a post-1994 South African society. The research sets out to explore in what manner theatre can be language-specific, while at the same time being able to cross language contexts. This exploration is driven by the wish to develop strategies for creating Afrikaans theatre that is able to reflect on a society “united in diversity”. In this regard it is argued that for theatre to be able to both retain and cross language barriers, processes of bonding and bridging are necessary. The thesis sets out first to explain why these processes are required and then to suggest ways in which such processes can be implemented in practice. A triangular approach is used, in which conceptual and theoretical frameworks are developed to reflect on actual theatre practices. Three of my own productions are used as case studies, namely Hex (2000; 2003), Lady Anne (2007) and Ekspedisies (2008). These productions can be understood to be “boundary objects” in Henk Borgdorff’s (2012: 177) sense of the word, in that they fulfil a dual function: they are artistic productions that can also be reconstituted to serve a research purpose beyond the productions themselves. All three works were first created for public consumption before becoming cases for this thesis. Many of the strategies that were developed and tested in creating these productions are examples of ways in which bonding and bridging in Afrikaans language theatre can be understood. Chapter One of the thesis contextualises the political currents and events that necessitated the impulse towards “bonding and bridging”. In this case the political and ethical impetus behind the practical explorations has been related predominantly to the democratisation of South African society, in which a paradigm shift happened from viewing the Afrikaans language as one over many to one amongst many. Within a multilingual South Africa, concerns are raised about ways in which to create theatre in South African languages other than English (often understood to be the only possible bridging language) that are able to cross language divides. Following this introduction to language-related concerns, Chapter Two explains how the shift from apartheid to democracy made space for shifts in identity – on personal as well as institutional levels: a progression from essentialised notions of culture to the celebration of plurality. This progression is then related to theatre, with an explanation of how the post-1994 theatre landscape demanded a reimagining of the form and function of theatre. In this re-imagination the notion of a “third space” is important; something that is introduced in this chapter as an alternative to polarised identity constructions. The function of the “third space” as an in-between space and a meeting point for diverse people and entities is a strong underlying theme of this thesis and it serves as a reoccurring touchstone to the ideas put forward. Chapter Three discusses the South African arts festival culture and its contribution to the South African theatre landscape. Particular focus is placed on the Klein Karoo National Arts festival (KKNK) as a platform for the development of the Afrikaans language within a post-1994 context. What is emphasized in particular is the attempt by the KKNK festival to be linguistically and culturally exploratory and inclusive in the face of language protectionism. After the contextual background of the first three chapters, the thesis shifts to an analysis of theories related to “hybridity” and “syncretism”. In Chapter Four the argument is put forward that of the various inclusive performance and theatre models that represent a multicultural society, the most responsive forms are those that are syncretic and hybrid. Principles that can contribute to the unification and merging of diverse and polarized societal groups are described, and suggestions are made for possible ways to bring about bonding and bridging within cultural practices. Having introduced these principles, examples are offered of how these theories might be understood in other disciplines, namely, religious studies, anthropology, history and a range of cultural practices. Following this broad discussion, Chapter Five describes syncretism and hybridity more specifically in theatre by means of relevant examples. Taking the discussion further into the realm of application, Chapter Six offers an overview of “workshop theatre”, “translation” and “collage making” as strategies for putting theories of hybridity and syncretism into practice. This is followed (in Chapters Seven, Eight and Nine) by a discussion of the three productions (Hex, Lady Anne and Ekspedisies) as case studies that demonstrate how these theories can be understood in practice. Practical strategies for bridging language divides are foregrounded, such as code switching as an approach for enabling a “co-habitation” of languages; physical theatre as a means for crossing language divides; and the creation of more than one language version of a production as a tactic to accommodate shifting contexts. Following on from the discoveries made in the foregoing chapters, I conclude that theories and practices related to notions of “third space”, “hybridity” and “syncretism” are ideal for creating theatre forms (in the Afrikaans language in particular) that can truly reflect a South African society which is “united in diversity”. The thesis ends by offering suggestions for ways in which new, future identities, can be developed.
- Full Text:
- Date Issued: 2016
- Authors: Gehring, Heike
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2165 , http://hdl.handle.net/10962/d1021269
- Description: This thesis investigates the possibilities for syncretic Afrikaans language theatre within a post-1994 South African society. The research sets out to explore in what manner theatre can be language-specific, while at the same time being able to cross language contexts. This exploration is driven by the wish to develop strategies for creating Afrikaans theatre that is able to reflect on a society “united in diversity”. In this regard it is argued that for theatre to be able to both retain and cross language barriers, processes of bonding and bridging are necessary. The thesis sets out first to explain why these processes are required and then to suggest ways in which such processes can be implemented in practice. A triangular approach is used, in which conceptual and theoretical frameworks are developed to reflect on actual theatre practices. Three of my own productions are used as case studies, namely Hex (2000; 2003), Lady Anne (2007) and Ekspedisies (2008). These productions can be understood to be “boundary objects” in Henk Borgdorff’s (2012: 177) sense of the word, in that they fulfil a dual function: they are artistic productions that can also be reconstituted to serve a research purpose beyond the productions themselves. All three works were first created for public consumption before becoming cases for this thesis. Many of the strategies that were developed and tested in creating these productions are examples of ways in which bonding and bridging in Afrikaans language theatre can be understood. Chapter One of the thesis contextualises the political currents and events that necessitated the impulse towards “bonding and bridging”. In this case the political and ethical impetus behind the practical explorations has been related predominantly to the democratisation of South African society, in which a paradigm shift happened from viewing the Afrikaans language as one over many to one amongst many. Within a multilingual South Africa, concerns are raised about ways in which to create theatre in South African languages other than English (often understood to be the only possible bridging language) that are able to cross language divides. Following this introduction to language-related concerns, Chapter Two explains how the shift from apartheid to democracy made space for shifts in identity – on personal as well as institutional levels: a progression from essentialised notions of culture to the celebration of plurality. This progression is then related to theatre, with an explanation of how the post-1994 theatre landscape demanded a reimagining of the form and function of theatre. In this re-imagination the notion of a “third space” is important; something that is introduced in this chapter as an alternative to polarised identity constructions. The function of the “third space” as an in-between space and a meeting point for diverse people and entities is a strong underlying theme of this thesis and it serves as a reoccurring touchstone to the ideas put forward. Chapter Three discusses the South African arts festival culture and its contribution to the South African theatre landscape. Particular focus is placed on the Klein Karoo National Arts festival (KKNK) as a platform for the development of the Afrikaans language within a post-1994 context. What is emphasized in particular is the attempt by the KKNK festival to be linguistically and culturally exploratory and inclusive in the face of language protectionism. After the contextual background of the first three chapters, the thesis shifts to an analysis of theories related to “hybridity” and “syncretism”. In Chapter Four the argument is put forward that of the various inclusive performance and theatre models that represent a multicultural society, the most responsive forms are those that are syncretic and hybrid. Principles that can contribute to the unification and merging of diverse and polarized societal groups are described, and suggestions are made for possible ways to bring about bonding and bridging within cultural practices. Having introduced these principles, examples are offered of how these theories might be understood in other disciplines, namely, religious studies, anthropology, history and a range of cultural practices. Following this broad discussion, Chapter Five describes syncretism and hybridity more specifically in theatre by means of relevant examples. Taking the discussion further into the realm of application, Chapter Six offers an overview of “workshop theatre”, “translation” and “collage making” as strategies for putting theories of hybridity and syncretism into practice. This is followed (in Chapters Seven, Eight and Nine) by a discussion of the three productions (Hex, Lady Anne and Ekspedisies) as case studies that demonstrate how these theories can be understood in practice. Practical strategies for bridging language divides are foregrounded, such as code switching as an approach for enabling a “co-habitation” of languages; physical theatre as a means for crossing language divides; and the creation of more than one language version of a production as a tactic to accommodate shifting contexts. Following on from the discoveries made in the foregoing chapters, I conclude that theories and practices related to notions of “third space”, “hybridity” and “syncretism” are ideal for creating theatre forms (in the Afrikaans language in particular) that can truly reflect a South African society which is “united in diversity”. The thesis ends by offering suggestions for ways in which new, future identities, can be developed.
- Full Text:
- Date Issued: 2016
Institutional change, institutional isolation and biodiversity governance in South Africa: a case study of the trout industry in alien and invasive species regulatory reforms
- Authors: Marire, Juniours
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/639 , vital:19977
- Description: The world, in recent decades, has witnessed an incalculable surge in global “wicked” policy problems that have long-term, and most often irreversible, impacts, not least terrorism, climate change, biodiversity losses and desertification. Wicked problems are wicked because there is no single epistemological system that can adequately coordinate policy action for addressing them. Literature abounds with international case studies of opposition to national institutions that are designed to put into effect global and regional policies for resolving wicked problems. This raises questions about what constitutes reasonable institutions, how such institutions can be designed and why societies sometimes fail to develop such institutions despite the obvious need for them. As a point of entry into these issues, the thesis adapted and extended the Northean (2007, 2012) macro meta-theoretic framework for studying the violence-development relationship, which focuses on the role of political and economic competition in the emergence of ‘right’ institutions that promote development, while containing violence. The Northean framework conceptualises two mutually exclusive social orders – the limited access order and the open access order – which provide the socio-cultural context for the evolution of specific institutions. The macro meta-theoretic framework was transformed into a micro metatheoretic framework in such a way that the limited access order and the open access order co-existed in the evolution of specific institutions. This reconceptualisation built on Bromley’s (2004, 2006) two realms of public policy: the realm of reasons (legislative-judicial system) and the realm of rules (administrative system) as well as the feminist concept of epistemic violence, which broadened the concept of violence from being exclusively physical to including the sociocognitive. The feminist concept of epistemic oppression logically fitted into, and became a new sub-category of, Commons’ (1899, 1924, 1934) theories of sovereignty and negotiational psychology. The innovations showed that either of these realms can be a limited access order, while the other can be an open access order or both can be open access orders or both can be limited access orders. The conceptual innovations were then used as an interpretive scheme in analysing the evolution of the South African invasive alien species regulatory reforms under the National Environmental Management: Biodiversity Act of 2004, using a case study of the trout sector, which was the most opposed to the reforms. There was a general perception among socioeconomic sectors that utilise invasive alien species that the regulatory reform processes for the governance of such species had institutionally isolated the sectors. Because of this perception, the regulatory reform process was contested, and implementation of the Fifth Chapter of the Act, which deals with the governance of invasive alien species, was delayed for nearly a decade. The thesis evaluated whether institutional isolation existed and how and why it came to be since it has implications for the reasonableness of emerging regulatory institutions, economic performance of sectors and efficient allocation of fiscal resources in institutional design processes. A mixed methods methodology was used, which included data analysis techniques such as semiosis, exploratory factor analysis, econometric estimation and document analysis. Policy documents, an online survey and key informant interviews comprised the data. The findings suggested six dimensions of institutional change that a theory of institutional change might have to address: the origin and continuity of pecuniary institutions; selfreinforcing mechanisms of the limited access policymaking order; succession and disbandment of the limited access policymaking order; exclusivity of negotiations in institutional design; tiers of institutional isolation; and the role of administrative discontinuities. Findings suggested that institutional isolation existed in the regulatory process, manifesting in three forms: administrative isolation, epistemological isolation and sectoral isolation. Administrative isolation was the most complex of the three in that it also involved a less obvious process of institutional isolation in the form of administrative redefinition of opportunity sets that were already legislatively redefined. The mechanisms of institutional isolation through which administrative isolation was sustained were administrative financing of research and careerism. The two mechanisms created a revolving door-type scenario through which invasion biologists supplied the administrative agency with candidates for senior (decision making) positions and the administrative agency, in turn, demanded specific types of knowledge over which the same epistemic community had a monopoly. The revolving door-type scenario was found to ideologically and physically entrench invasion biologists into the regulatory community. The consequence of the entrenchment was institutional hegemony, which manifested itself through the mechanism of epistemic violence insofar as the invasion biologists became the epistemic arbiters about what kinds of ideas and institutions really mattered in the governance of invasive alien species. Econometric estimates suggested that the extent to which an emerging institution is perceived to be reasonable by regulated sectors depends on the extent to which the institution is designed in a participatory and inclusive manner (that is, using integrative knowledge systems), the extent to which the designers used credible evidence and contextualised international evidence as well as the extent to which the emergent biodiversity governance institution was anthropocentric. However, findings suggested that the South African regulatory reform process fell short on all these four dimensions of reasonable institutions, which is characteristic of institutional design process shaped by hegemonic social imaginaries, resulting in institutional isolation. Emerging from the findings are several theoretical insights. Bush’s (1987) concept of institutional spaces under the Veblenian Dichotomy was extended, the result of which was identification of two stable institutional equilibria – one ceremonial and another instrumental. The ceremonial equilibrium was a typical limited access policymaking order and was responsible for the historical and present emergence of regressive institutions. Findings also suggested that the entrenched invasion biologists ceremonially encapsulated the knowledge fund that had been accumulated since the 1980s, which could have facilitated the consensual design of regulatory institutions for invasive alien species without protracted controversy. Findings suggested that a limited access policymaking order could only be disbanded by the intervention of an external sovereign agent (in this case the office of the state president) since the administrative agency, and the epistemic community that advised it, adopted the solutions that were empirically tested and proposed in the 1980s only after the intervention of the external sovereign agent. The instrumental equilibrium repealed the contested prisoner’s dilemma that was characteristic of the policy process and turned it into an assurance policy game by facilitating the identification of common interests. This finding logically links the study to a recent theoretical development in institutional theory – Ordonomics – which focuses on the causality between ideas and institutions. The findings imply that it is possible to design reasonable institutions as long as integrative (transdisciplinary) knowledge systems, including the non-scientific knowledge of the resource users, are incorporated. Integrative knowledge systems facilitate semantic innovations, which create social DNA, but epistemic violence destroys social DNA. They also imply that reliance on unidisciplinary knowledge systems in institutional design induces a large and inefficient transaction cost burden of public policy on the fiscus and private agents alike because of the inevitability of controversy, especially for wicked policy problems.
- Full Text:
- Date Issued: 2016
- Authors: Marire, Juniours
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/639 , vital:19977
- Description: The world, in recent decades, has witnessed an incalculable surge in global “wicked” policy problems that have long-term, and most often irreversible, impacts, not least terrorism, climate change, biodiversity losses and desertification. Wicked problems are wicked because there is no single epistemological system that can adequately coordinate policy action for addressing them. Literature abounds with international case studies of opposition to national institutions that are designed to put into effect global and regional policies for resolving wicked problems. This raises questions about what constitutes reasonable institutions, how such institutions can be designed and why societies sometimes fail to develop such institutions despite the obvious need for them. As a point of entry into these issues, the thesis adapted and extended the Northean (2007, 2012) macro meta-theoretic framework for studying the violence-development relationship, which focuses on the role of political and economic competition in the emergence of ‘right’ institutions that promote development, while containing violence. The Northean framework conceptualises two mutually exclusive social orders – the limited access order and the open access order – which provide the socio-cultural context for the evolution of specific institutions. The macro meta-theoretic framework was transformed into a micro metatheoretic framework in such a way that the limited access order and the open access order co-existed in the evolution of specific institutions. This reconceptualisation built on Bromley’s (2004, 2006) two realms of public policy: the realm of reasons (legislative-judicial system) and the realm of rules (administrative system) as well as the feminist concept of epistemic violence, which broadened the concept of violence from being exclusively physical to including the sociocognitive. The feminist concept of epistemic oppression logically fitted into, and became a new sub-category of, Commons’ (1899, 1924, 1934) theories of sovereignty and negotiational psychology. The innovations showed that either of these realms can be a limited access order, while the other can be an open access order or both can be open access orders or both can be limited access orders. The conceptual innovations were then used as an interpretive scheme in analysing the evolution of the South African invasive alien species regulatory reforms under the National Environmental Management: Biodiversity Act of 2004, using a case study of the trout sector, which was the most opposed to the reforms. There was a general perception among socioeconomic sectors that utilise invasive alien species that the regulatory reform processes for the governance of such species had institutionally isolated the sectors. Because of this perception, the regulatory reform process was contested, and implementation of the Fifth Chapter of the Act, which deals with the governance of invasive alien species, was delayed for nearly a decade. The thesis evaluated whether institutional isolation existed and how and why it came to be since it has implications for the reasonableness of emerging regulatory institutions, economic performance of sectors and efficient allocation of fiscal resources in institutional design processes. A mixed methods methodology was used, which included data analysis techniques such as semiosis, exploratory factor analysis, econometric estimation and document analysis. Policy documents, an online survey and key informant interviews comprised the data. The findings suggested six dimensions of institutional change that a theory of institutional change might have to address: the origin and continuity of pecuniary institutions; selfreinforcing mechanisms of the limited access policymaking order; succession and disbandment of the limited access policymaking order; exclusivity of negotiations in institutional design; tiers of institutional isolation; and the role of administrative discontinuities. Findings suggested that institutional isolation existed in the regulatory process, manifesting in three forms: administrative isolation, epistemological isolation and sectoral isolation. Administrative isolation was the most complex of the three in that it also involved a less obvious process of institutional isolation in the form of administrative redefinition of opportunity sets that were already legislatively redefined. The mechanisms of institutional isolation through which administrative isolation was sustained were administrative financing of research and careerism. The two mechanisms created a revolving door-type scenario through which invasion biologists supplied the administrative agency with candidates for senior (decision making) positions and the administrative agency, in turn, demanded specific types of knowledge over which the same epistemic community had a monopoly. The revolving door-type scenario was found to ideologically and physically entrench invasion biologists into the regulatory community. The consequence of the entrenchment was institutional hegemony, which manifested itself through the mechanism of epistemic violence insofar as the invasion biologists became the epistemic arbiters about what kinds of ideas and institutions really mattered in the governance of invasive alien species. Econometric estimates suggested that the extent to which an emerging institution is perceived to be reasonable by regulated sectors depends on the extent to which the institution is designed in a participatory and inclusive manner (that is, using integrative knowledge systems), the extent to which the designers used credible evidence and contextualised international evidence as well as the extent to which the emergent biodiversity governance institution was anthropocentric. However, findings suggested that the South African regulatory reform process fell short on all these four dimensions of reasonable institutions, which is characteristic of institutional design process shaped by hegemonic social imaginaries, resulting in institutional isolation. Emerging from the findings are several theoretical insights. Bush’s (1987) concept of institutional spaces under the Veblenian Dichotomy was extended, the result of which was identification of two stable institutional equilibria – one ceremonial and another instrumental. The ceremonial equilibrium was a typical limited access policymaking order and was responsible for the historical and present emergence of regressive institutions. Findings also suggested that the entrenched invasion biologists ceremonially encapsulated the knowledge fund that had been accumulated since the 1980s, which could have facilitated the consensual design of regulatory institutions for invasive alien species without protracted controversy. Findings suggested that a limited access policymaking order could only be disbanded by the intervention of an external sovereign agent (in this case the office of the state president) since the administrative agency, and the epistemic community that advised it, adopted the solutions that were empirically tested and proposed in the 1980s only after the intervention of the external sovereign agent. The instrumental equilibrium repealed the contested prisoner’s dilemma that was characteristic of the policy process and turned it into an assurance policy game by facilitating the identification of common interests. This finding logically links the study to a recent theoretical development in institutional theory – Ordonomics – which focuses on the causality between ideas and institutions. The findings imply that it is possible to design reasonable institutions as long as integrative (transdisciplinary) knowledge systems, including the non-scientific knowledge of the resource users, are incorporated. Integrative knowledge systems facilitate semantic innovations, which create social DNA, but epistemic violence destroys social DNA. They also imply that reliance on unidisciplinary knowledge systems in institutional design induces a large and inefficient transaction cost burden of public policy on the fiscus and private agents alike because of the inevitability of controversy, especially for wicked policy problems.
- Full Text:
- Date Issued: 2016
Links between valley confinement, landforms and vegetation distribution in a semi-arid valley floor environment, Baviaanskloof, South Africa
- Authors: Smith-Adao, Lindie B
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/953 , vital:20006
- Description: Although a large body of international literature has advanced our understanding of river systems, a considerable amount of gaps exit in the knowledge of dryland systems. River systems reflect complex interactions between biophysical processes and patterns. Understanding how processes generate observed patterns and, in turn, how patterns influence processes is crucial to understanding river structure and function. It requires an interdisciplinary approach in both research and resulting applications. The aim of this thesis was to examine the relationship between valley confinement, fluvial style, valley floor morphology and vegetation in the semi-arid environment of the Baviaanskloof river catchment, South Africa. This interdisciplinary investigation used a mixed method approach that involved desktop analyses and field surveys to understand dynamics at multiple scales, from the whole catchment to local (site, reach and quadrat or sample plot) scales. The desktop analyses included historical rainfall patterns and climate extremes, aerial photograph time-series and remote sensing greenness indices, and the field surveys focussed on cross-valley landform profiles, groundwater depth levels, sediment size distribution and soil chemistry, and vegetation distribution patterns. Based on the integrative assessment of these techniques a framework was developed of the links between valley confinement, surface-groundwater interaction, hydrogeomorphic processes and landforms, vegetation and human activities. Study findings highlighted the fact that very strong links exist between these factors. In this semi-arid area water availability (groundwater and streamflow conditions) was the primary control on valley floor vegetation composition and patterning. One group of species was associated with the wetted channel reaches at confined and semi-confined valley settings, while the other was associated with dry bed channel reaches at unconfined valley settings. The analyses also indicated that the environmental variables which best explained the variation in vegetation at the differing geomorphic landforms were related to landform position (elevation and distance), sediment size (fine and coarse sand) and available phosphorus (i.e. human impacts). The different plants, in turn, also affected landforms through their influence on sediment erosion, transport and deposition. Specially, they build, maintained or modified geomorphic landforms at confined, semi-confined and unconfined valley settings across the valley floor. Valley confinement was a primary control influencing hydrogeomorphic processes and their associated landforms. Alluvial fans and terraces acted as critical additional controls at especially the unconfined valley setting. Implications for restoration efforts in the catchment included strategies that took cognisance of: active revegetation on floodplain surfaces related to former agricultural fields; channel switching associated with the highly dynamic and unpredictable nature of geomorphic features; unstable multi-thread braided channels in the unconfined valley setting; and the selection of representative monitoring sites.
- Full Text:
- Date Issued: 2016
- Authors: Smith-Adao, Lindie B
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/953 , vital:20006
- Description: Although a large body of international literature has advanced our understanding of river systems, a considerable amount of gaps exit in the knowledge of dryland systems. River systems reflect complex interactions between biophysical processes and patterns. Understanding how processes generate observed patterns and, in turn, how patterns influence processes is crucial to understanding river structure and function. It requires an interdisciplinary approach in both research and resulting applications. The aim of this thesis was to examine the relationship between valley confinement, fluvial style, valley floor morphology and vegetation in the semi-arid environment of the Baviaanskloof river catchment, South Africa. This interdisciplinary investigation used a mixed method approach that involved desktop analyses and field surveys to understand dynamics at multiple scales, from the whole catchment to local (site, reach and quadrat or sample plot) scales. The desktop analyses included historical rainfall patterns and climate extremes, aerial photograph time-series and remote sensing greenness indices, and the field surveys focussed on cross-valley landform profiles, groundwater depth levels, sediment size distribution and soil chemistry, and vegetation distribution patterns. Based on the integrative assessment of these techniques a framework was developed of the links between valley confinement, surface-groundwater interaction, hydrogeomorphic processes and landforms, vegetation and human activities. Study findings highlighted the fact that very strong links exist between these factors. In this semi-arid area water availability (groundwater and streamflow conditions) was the primary control on valley floor vegetation composition and patterning. One group of species was associated with the wetted channel reaches at confined and semi-confined valley settings, while the other was associated with dry bed channel reaches at unconfined valley settings. The analyses also indicated that the environmental variables which best explained the variation in vegetation at the differing geomorphic landforms were related to landform position (elevation and distance), sediment size (fine and coarse sand) and available phosphorus (i.e. human impacts). The different plants, in turn, also affected landforms through their influence on sediment erosion, transport and deposition. Specially, they build, maintained or modified geomorphic landforms at confined, semi-confined and unconfined valley settings across the valley floor. Valley confinement was a primary control influencing hydrogeomorphic processes and their associated landforms. Alluvial fans and terraces acted as critical additional controls at especially the unconfined valley setting. Implications for restoration efforts in the catchment included strategies that took cognisance of: active revegetation on floodplain surfaces related to former agricultural fields; channel switching associated with the highly dynamic and unpredictable nature of geomorphic features; unstable multi-thread braided channels in the unconfined valley setting; and the selection of representative monitoring sites.
- Full Text:
- Date Issued: 2016
Observational cosmology with imperfect data
- Authors: Bester, Hertzog Landman
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/463 , vital:19961
- Description: We develop a formalism suitable to infer the background geometry of a general spherically symmetric dust universe directly from data on the past lightcone. This direct observational approach makes minimal assumptions about inaccessible parts of the Universe. The non-parametric and Bayesian framework we propose provides a very direct way to test one of the most fundamental underlying assumptions of concordance cosmology viz. the Copernican principle. We present the Copernicus algorithm for this purpose. By applying the algorithm to currently available data, we demonstrate that it is not yet possible to confirm or refute the validity of the Copernican principle within the proposed framework. This is followed by an investigation which aims to determine which future data will best be able to test the Copernican principle. Our results on simulated data suggest that, besides the need to improve the current data, it will be important to identify additional model independent observables for this purpose. The main difficulty with current data is their inability to constrain the value of the cosmological constant. We show how redshift drift data could be used to infer its value with minimal assumptions about the nature of the early Universe. We also discuss some alternative applications of the algorithm.
- Full Text:
- Date Issued: 2016
- Authors: Bester, Hertzog Landman
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/463 , vital:19961
- Description: We develop a formalism suitable to infer the background geometry of a general spherically symmetric dust universe directly from data on the past lightcone. This direct observational approach makes minimal assumptions about inaccessible parts of the Universe. The non-parametric and Bayesian framework we propose provides a very direct way to test one of the most fundamental underlying assumptions of concordance cosmology viz. the Copernican principle. We present the Copernicus algorithm for this purpose. By applying the algorithm to currently available data, we demonstrate that it is not yet possible to confirm or refute the validity of the Copernican principle within the proposed framework. This is followed by an investigation which aims to determine which future data will best be able to test the Copernican principle. Our results on simulated data suggest that, besides the need to improve the current data, it will be important to identify additional model independent observables for this purpose. The main difficulty with current data is their inability to constrain the value of the cosmological constant. We show how redshift drift data could be used to infer its value with minimal assumptions about the nature of the early Universe. We also discuss some alternative applications of the algorithm.
- Full Text:
- Date Issued: 2016
Being a black mine worker in South Africa: the case of Anglo Platinum Mine
- Authors: Maseko, Robert
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/651 , vital:19978
- Description: This thesis presents a decolonial perspective on the experience of being a black mineworker in post-apartheid South Africa with specific reference to the Platinum Belt. It seeks to understand what it means to be a black mineworker by unmasking and analysing the existence and prevalence of coloniality in contemporary South Africa despite the end of formal colonialism (i.e. apartheid). As a world-wide system, coloniality has different dimensions which all speak to and highlight continuities between the period of colonialism and the post-colonial period. These dimensions are coloniality of power, coloniality of being and coloniality of knowledge. The power structure of coloniality produces and reproduces the identity of the black mineworker in present-day South Africa as a sub-ontological being devoid of an authentic humanity such that the mineworker is depicted as incapable of rational thought and knowledge. The existential condition of the black mineworker is symptomatic of the generic experience of being a racialised subject of colour in the current global power structure predicated on the dominance and hegemony of Western-centred modernity. The black mineworker exists on the darker side of Western-centred modernity, living a life of wretchedness and continuing to suffer the colonial wound in the absence of formal colonialism and apartheid. The mineworker is disposable and dispensable and lives and works in the shadow of death. In pursuing this course of reasoning, I deploy the epistemic method of ‘shifting the geography of reason’ in order to read the experience of mineworkers in South Africa from the locus of enunciation of the oppressed subject within the scheme of a colonial power differential based on a hierarchy of humanity. This method allows me to speak with and from the perspective of the black mineworkers in the Platinum Belt as opposed to speaking for and about them. I reach the conclusion that being a platinum mineworker in post-apartheid South Africa is a racial and market determined identity of colonialised subjectivity that relegates the dominated subject (the black mineworker) to the realm of the subhuman. In setting the context for this claim, I trace the origins and development of the black mineworker in South Africa with reference to historical processes such as dispossession and proletarianisation. Empirically, the thesis is rooted in a contemporary case study of mainly Anglo Platinum Mine, which involved comprehensive fieldwork focusing on the present lived realities of platinum mineworkers. The dignity and humanity of these black mineworkers has still not returned despite twenty years of democratic rule in South Africa, such that race remains a crucial organising principle in postapartheid South Africa.
- Full Text:
- Date Issued: 2016
- Authors: Maseko, Robert
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/651 , vital:19978
- Description: This thesis presents a decolonial perspective on the experience of being a black mineworker in post-apartheid South Africa with specific reference to the Platinum Belt. It seeks to understand what it means to be a black mineworker by unmasking and analysing the existence and prevalence of coloniality in contemporary South Africa despite the end of formal colonialism (i.e. apartheid). As a world-wide system, coloniality has different dimensions which all speak to and highlight continuities between the period of colonialism and the post-colonial period. These dimensions are coloniality of power, coloniality of being and coloniality of knowledge. The power structure of coloniality produces and reproduces the identity of the black mineworker in present-day South Africa as a sub-ontological being devoid of an authentic humanity such that the mineworker is depicted as incapable of rational thought and knowledge. The existential condition of the black mineworker is symptomatic of the generic experience of being a racialised subject of colour in the current global power structure predicated on the dominance and hegemony of Western-centred modernity. The black mineworker exists on the darker side of Western-centred modernity, living a life of wretchedness and continuing to suffer the colonial wound in the absence of formal colonialism and apartheid. The mineworker is disposable and dispensable and lives and works in the shadow of death. In pursuing this course of reasoning, I deploy the epistemic method of ‘shifting the geography of reason’ in order to read the experience of mineworkers in South Africa from the locus of enunciation of the oppressed subject within the scheme of a colonial power differential based on a hierarchy of humanity. This method allows me to speak with and from the perspective of the black mineworkers in the Platinum Belt as opposed to speaking for and about them. I reach the conclusion that being a platinum mineworker in post-apartheid South Africa is a racial and market determined identity of colonialised subjectivity that relegates the dominated subject (the black mineworker) to the realm of the subhuman. In setting the context for this claim, I trace the origins and development of the black mineworker in South Africa with reference to historical processes such as dispossession and proletarianisation. Empirically, the thesis is rooted in a contemporary case study of mainly Anglo Platinum Mine, which involved comprehensive fieldwork focusing on the present lived realities of platinum mineworkers. The dignity and humanity of these black mineworkers has still not returned despite twenty years of democratic rule in South Africa, such that race remains a crucial organising principle in postapartheid South Africa.
- Full Text:
- Date Issued: 2016
Development of an enzyme-synergy based bioreactor system for the beneficiation of apple pomace lignocellulosic waste
- Authors: Abboo, Sagaran
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/315 , vital:19947
- Description: Due to the finite supply of non-renewable fossil fuels, agro-industrial wastes are identified as alternate, renewable sources for energy supply. Large amounts of fruit waste are generated in South Africa due to fruit juice and wine processing from apples, grapes and citrus fruit. Apple pomace is the solid residue that is left over after juice, cider and wine processing and constitutes between 25-30% of the total fruit. On a global scale millions of tonnes of apple pomace are produced; between 2006-2007 over 46 million tonnes were produced. In South Africa a total production of 244 469 tonnes were produced during the 2011- 2012 season. Initially, apple pomace was regarded as a waste by-product used for animal feed and compost in soil, however presently it is considered a source of dietary fiber and natural antioxidants like polyphenols. In addition, apple pomace has a high carbohydrate content and can be enzymatically hydrolysed to produce sugar monomers which, in turn, can be fermented by yeasts to produce bioethanol. The polyphenols present in apple pomace can be used for their health properties, and the bioethanol can be used as a replacement for fossil fuel. Apple pomace is lignocellulosic in nature and consists of hemicellulose, cellulose, lignin and pectin. A combination of enzymes such as cellulases, hemicellulases, pectinases and lignases are required to operate in synergy for the degradation of lignocellulosic biomass. This is due to the recalcitrant nature of lignocellulose. This study investigated the degradation of apple pomace using a combination of commercially obtained enzyme cocktails viz. Viscozyme L , Celluclast 1.5L and Novozyme 188. The commercial enzymes Viscozyme L and Celluclast 1.5L were added in a ratio of 1:1 (50%:50%). The final concentrations of the enzymes were 0.019 mg/ml each. Novozyme 188 was added to provide a final concentration of 0.0024 mg/ml. A novel cost effective 20L bioreactor was designed, constructed and implemented for the degradation of apple pomace to produce value added products. The hydrolysis of the apple pomace was performed initially in 1 L flasks (batch fed) and, once optimized, scaled up to a 20 L bioreactor in batch mode. The bioreactors were operated at room temperature (22 ± 2ºC) and in an unbuffered system. The sugars released were detected and quantified using an optimized validated HPLC method established in this study. The sugars released in the bioreactors were mainly glucose, galactose, arabinose, cellobiose and fructose. The polyphenols released in this study were gallic acid, catechin, epicatechin, chlorogenic acid, rutin and phloridzin, which have a number of health benefits. The simultaneous analyses of the polyphenols were performed using a newly developed and validated HPLC method established in this study. This method was developed to detect nine polyphenols simultaneously. The two HPLC methods developed and validated in this study for the analysis of sugars and polyphenols demonstrated good accuracy, precision, reproducibility, linearity, robustness and sensitivity. Both analytical methods were validated according to the International Convention on Harmonization (ICH). The HPLC parameters for sugar analysis were: refractive index (RI) as the detection mode, the stationary phase was a ligand-exchange sugar column (Shodex SP0810) and an aqueous mobile phase in isocratic mode was used. The HPLC method for polyphenols employed UV diode array detection (DAD) as the detection mode, a reverse phase column as the stationary phase and a mobile phase of consisting of 0.01 M phosphoric acid in water and 100% methanol using gradient elution mode. The highest concentrations of sugars released in the novel 20 L bioreactor with 20% apple pomace (w/v) substrate loading were as follow: glucose (6.5 mg/ml), followed by galactose (2.1 mg/ml), arabinose (1.4 mg/ml), cellobiose (0.7 mg/ml) and fructose (0.5 mg/ml). The amounts of polyphenols released at 20% (w/v) apple pomace substrate were epicatechin (0.01 mg/ml), catechin (0.002 mg/ml), rutin (0.03 mg/ml), chlorogenic acid (0.002 mg/ml) and gallic acid 0.01 (mg/ml). Two mathematical models were developed in this study for kinetic analysis of lignocellulose (apple pomace) hydrolysis in the novel 20 L bioreactor, using the experimental data generated by the above HPLC analyses. The first model, modelling with regression, defines the hydrolysis of the sugars glucose, galactose, cellobiose and arabinose produced in the novel 20 L bioreactor at 5%, 10%, 15% and 20% (w/v) substrate concentrations. The regression model describes the sugars produced in the 20 L bioreactor by minimizing the error of the sugars released by finding a value for K which minimises the function which computes the sum of squares of errors between the solution curves and the data points. The second, more complex, model developed in this study used a system of differential equations model (ODE). This model solved the system by using a numerical method, such as the Runge-Kutta method, then fitted the solution curves to the data. Both models simulated (and had the ability to predict) the production of sugars in the novel 20 L bioreactor for apple pomace hydrolysis. These two models also revealed the time at which the maximum amount of sugars were released, which revealed the optimum time to run the 20 L bioreactor in order to be more cost effective. The optimum time for maximum glucose (the main sugar used in fermentation for biofuel production) release was determined to be around 60 h. The ODE model, in addition, determined the rate at which the substrate became depleted, as well as the rate at which the enzymes became deactivated for the various substrate loadings in the 20 L bioreactor. A third model was developed to determine the optimal running cost of the bioreactor which incorporated the substrate loading and the amount of glucose (g/L) produced. The novel 20 L bioreactor constructed from cost effective materials demonstrated that agro-industrial waste can be converted to value-added products by lignocellolytic enzymes. The sugars released from apple pomace can be used in biofuel production and the polyphenols as food supplements and nutraceuticals for health benefits. This novel study contributes to agro-industrial waste beneficiation via fuel production. In addition, using agro-industrial waste for the generation of value added products (instead of mere disposal) will help prevent environmental pollution.
- Full Text:
- Date Issued: 2016
- Authors: Abboo, Sagaran
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/315 , vital:19947
- Description: Due to the finite supply of non-renewable fossil fuels, agro-industrial wastes are identified as alternate, renewable sources for energy supply. Large amounts of fruit waste are generated in South Africa due to fruit juice and wine processing from apples, grapes and citrus fruit. Apple pomace is the solid residue that is left over after juice, cider and wine processing and constitutes between 25-30% of the total fruit. On a global scale millions of tonnes of apple pomace are produced; between 2006-2007 over 46 million tonnes were produced. In South Africa a total production of 244 469 tonnes were produced during the 2011- 2012 season. Initially, apple pomace was regarded as a waste by-product used for animal feed and compost in soil, however presently it is considered a source of dietary fiber and natural antioxidants like polyphenols. In addition, apple pomace has a high carbohydrate content and can be enzymatically hydrolysed to produce sugar monomers which, in turn, can be fermented by yeasts to produce bioethanol. The polyphenols present in apple pomace can be used for their health properties, and the bioethanol can be used as a replacement for fossil fuel. Apple pomace is lignocellulosic in nature and consists of hemicellulose, cellulose, lignin and pectin. A combination of enzymes such as cellulases, hemicellulases, pectinases and lignases are required to operate in synergy for the degradation of lignocellulosic biomass. This is due to the recalcitrant nature of lignocellulose. This study investigated the degradation of apple pomace using a combination of commercially obtained enzyme cocktails viz. Viscozyme L , Celluclast 1.5L and Novozyme 188. The commercial enzymes Viscozyme L and Celluclast 1.5L were added in a ratio of 1:1 (50%:50%). The final concentrations of the enzymes were 0.019 mg/ml each. Novozyme 188 was added to provide a final concentration of 0.0024 mg/ml. A novel cost effective 20L bioreactor was designed, constructed and implemented for the degradation of apple pomace to produce value added products. The hydrolysis of the apple pomace was performed initially in 1 L flasks (batch fed) and, once optimized, scaled up to a 20 L bioreactor in batch mode. The bioreactors were operated at room temperature (22 ± 2ºC) and in an unbuffered system. The sugars released were detected and quantified using an optimized validated HPLC method established in this study. The sugars released in the bioreactors were mainly glucose, galactose, arabinose, cellobiose and fructose. The polyphenols released in this study were gallic acid, catechin, epicatechin, chlorogenic acid, rutin and phloridzin, which have a number of health benefits. The simultaneous analyses of the polyphenols were performed using a newly developed and validated HPLC method established in this study. This method was developed to detect nine polyphenols simultaneously. The two HPLC methods developed and validated in this study for the analysis of sugars and polyphenols demonstrated good accuracy, precision, reproducibility, linearity, robustness and sensitivity. Both analytical methods were validated according to the International Convention on Harmonization (ICH). The HPLC parameters for sugar analysis were: refractive index (RI) as the detection mode, the stationary phase was a ligand-exchange sugar column (Shodex SP0810) and an aqueous mobile phase in isocratic mode was used. The HPLC method for polyphenols employed UV diode array detection (DAD) as the detection mode, a reverse phase column as the stationary phase and a mobile phase of consisting of 0.01 M phosphoric acid in water and 100% methanol using gradient elution mode. The highest concentrations of sugars released in the novel 20 L bioreactor with 20% apple pomace (w/v) substrate loading were as follow: glucose (6.5 mg/ml), followed by galactose (2.1 mg/ml), arabinose (1.4 mg/ml), cellobiose (0.7 mg/ml) and fructose (0.5 mg/ml). The amounts of polyphenols released at 20% (w/v) apple pomace substrate were epicatechin (0.01 mg/ml), catechin (0.002 mg/ml), rutin (0.03 mg/ml), chlorogenic acid (0.002 mg/ml) and gallic acid 0.01 (mg/ml). Two mathematical models were developed in this study for kinetic analysis of lignocellulose (apple pomace) hydrolysis in the novel 20 L bioreactor, using the experimental data generated by the above HPLC analyses. The first model, modelling with regression, defines the hydrolysis of the sugars glucose, galactose, cellobiose and arabinose produced in the novel 20 L bioreactor at 5%, 10%, 15% and 20% (w/v) substrate concentrations. The regression model describes the sugars produced in the 20 L bioreactor by minimizing the error of the sugars released by finding a value for K which minimises the function which computes the sum of squares of errors between the solution curves and the data points. The second, more complex, model developed in this study used a system of differential equations model (ODE). This model solved the system by using a numerical method, such as the Runge-Kutta method, then fitted the solution curves to the data. Both models simulated (and had the ability to predict) the production of sugars in the novel 20 L bioreactor for apple pomace hydrolysis. These two models also revealed the time at which the maximum amount of sugars were released, which revealed the optimum time to run the 20 L bioreactor in order to be more cost effective. The optimum time for maximum glucose (the main sugar used in fermentation for biofuel production) release was determined to be around 60 h. The ODE model, in addition, determined the rate at which the substrate became depleted, as well as the rate at which the enzymes became deactivated for the various substrate loadings in the 20 L bioreactor. A third model was developed to determine the optimal running cost of the bioreactor which incorporated the substrate loading and the amount of glucose (g/L) produced. The novel 20 L bioreactor constructed from cost effective materials demonstrated that agro-industrial waste can be converted to value-added products by lignocellolytic enzymes. The sugars released from apple pomace can be used in biofuel production and the polyphenols as food supplements and nutraceuticals for health benefits. This novel study contributes to agro-industrial waste beneficiation via fuel production. In addition, using agro-industrial waste for the generation of value added products (instead of mere disposal) will help prevent environmental pollution.
- Full Text:
- Date Issued: 2016
The effect of kelp supplementation in formulated feed on the production performance and gut microbiota of South African abalone (Haliotis midae)
- Authors: Nel, Aldi
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/899 , vital:20001
- Description: Formulated feeds with a relatively low (< 5 % of dry mass) kelp (Ecklonia maxima) inclusion level are widely used on commercial abalone (Haliotis midae) farms in South Africa. Although the use of kelp, a major constituent of the natural diet of H. midae, as a dietary supplement is considered to enhance abalone growth and feed utilisation, there are no published studies which quantify the effects of kelp inclusion in formulated feeds. Furthermore, the physiological mechanisms by which kelp supplementation may positively influence abalone digestive physiology and growth are largely unknown. As the kelp supplement is comprised mostly of soluble fibres and abalone gut bacteria associated with macroalgae (and its fibrous polysaccharides) are known to play a key role in digestion, it was hypothesised that the kelp supplement influences the gut-bacterial community profiles of cultured abalone through prebiotic and other metabolic effects. The present thesis thus examined the effect of kelp supplementation on the performance of abalone (Haliotis midae) fed formulated feeds and explored the influence of a kelp supplement on the abalone gut microbiota and its function in the gastrointestinal tract. The key hypotheses of the study were that kelp supplementation in formulated feed: 1) enhances abalone growth; 2) causes a shift in abalone gut-bacterial community composition through a prebiotic-like effect; 3) may induce changes in crop morphology as a result of potential bacterial-associated increases in volatile short-chain fatty acids, and 4) alters digestive enzyme activities in the abalone gut through changes in bacterial-derived (exogenous) digestive enzymes. The growth-promoting efficacy of low-level kelp supplementation was tested by feeding isonitrogenous and isoenergetic experimental feeds containing 0.00 – 3.54 % kelp (dry mass) to sub-adult abalone (~43 mm shell length) for eight months under commercial farm conditions. The growth trial established that kelp supplementation (0.44 – 3.54 % of dry mass) promoted faster growth and improved feed conversion and protein efficiency ratios in cultured abalone compared to abalone fed the non-supplemented control diet, while there were no significant differences in growth for abalone fed the different kelp-supplemented diets (0.44, 0.88, 1.76 and 3.54 % of dry mass). Feed conversion and protein efficiency ratios displayed significant correlations with kelp level in the range of 0.00 – 3.54 % dry mass, and it is therefore recommended that kelp be included in the formulated feeds of cultured South African abalone at a rate of up to 3.54 % of dry mass. A kelp-supplemented (0.88 % dry weight inclusion) feed was fed to abalone under farm conditions to compare gut physiological parameters (crop morphology, digestive enzyme activities and the gut microbiota) in abalone against that of abalone fed an isonitrogenous and isoenergetic non-supplemented control feed. To establish if the observed higher abalone growth rates were related to improved gastrointestinal tract epithelium activity and integrity, as reflected by epithelial cell growth in response to potential changes in bacterial-derived short-chain fatty acid production, crop epithelial morphology was compared between abalone fed the kelp-supplemented and control feeds. Kelp supplementation did not induce any observable changes in crop epithelial cell height for farm-reared sub-adult abalone fed the experimental diets on-farm for seven weeks. This was attributed to the similar macronutrient compositions of kelp-supplemented and control diets and/ or the common diet history of experimental abalone from weaning to the initiation of the experiment. Digestive enzyme activity was compared between abalone fed a kelp-supplemented and a control feed during an on-farm feeding trial with sub-adult abalone. Gut samples were collected after seven weeks and colorimetric enzyme assays were performed for the polysaccharide-degrading enzymes amylase, alginate lyase, laminarinase and fucoidanase, and for acid protease, trypsin and chymotrypsin activity. Amylase and alginate lyase activities were relatively high, compared to the other enzymes. Polysaccharidase and acid protease activity levels did not differ significantly between abalone fed kelp-supplemented and control feeds, but a greater variability in enzyme activity levels was observed in abalone fed the control diet. It was hypothesised that this might be due to the kelp supplement promoting a more stable and less opportunistic gut-bacterial community than the control diet. Pooled gut samples of abalone fed the kelp-supplemented diet were used for proteomic analyses to identify the composition of enzyme proteins of both endogenous and exogenous origin in the abalone digestive system. The key polysaccharidases and proteases in the gut samples of kelp-supplemented formulated feed-fed abalone were all of abalone origin, whereas the bacterial enzymes were of the types that form part of intermediate reactions in metabolic pathways. The results suggested that bacterial enzymes play a different role to abalone endogenous enzymes in the digestion of formulated feed. While abalone enzymes appear to be the main degraders of carbohydrate and protein macromolecules, the profile of exogenous enzymes suggests that they perform bioconversions of smaller organic compounds. The profiles of gut-bacterial communities of farm-reared sub-adult abalone fed kelpsupplemented and control feeds on-farm for seven weeks were analysed with metagenomic pyrosequencing and DGGE analyses, using 16S rDNA-targeted amplified DNA. The results indicated a shift in gut-bacterial composition with a higher abundance of Mollicutes in abalone fed kelp-supplemented feed compared to those fed the control feed. DGGE band patterns displayed a greater within-group similarity in gut bacteria for abalone fed the kelpsupplemented diet and the presence of unique and variable bands for bacteria in the guts of abalone fed the control diet. It was concluded that when cultured abalone are fed kelpsupplemented formulated feeds, more stable gut bacterial communities are present compared to a more opportunistic gut-bacterial community in abalone fed non-supplemented feeds, and that the observed increase in Mollicutes could reflect the restoration of the abalone gut microbiota to a more natural state. The novel application of proteomics to abalone nutrition in the present study demonstrated that gut-bacterial enzymes may form part of many different metabolic pathways and suggests that the metabolism of the gut microbiota serves as an extension of the abalone’s digestive metabolism. Future studies should quantify the contribution of commensal gut-bacteria to cultured abalone nutrition by employing metabolomic studies to characterize the utilisation of bacterial-derived metabolites by the abalone host.
- Full Text:
- Date Issued: 2016
- Authors: Nel, Aldi
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/899 , vital:20001
- Description: Formulated feeds with a relatively low (< 5 % of dry mass) kelp (Ecklonia maxima) inclusion level are widely used on commercial abalone (Haliotis midae) farms in South Africa. Although the use of kelp, a major constituent of the natural diet of H. midae, as a dietary supplement is considered to enhance abalone growth and feed utilisation, there are no published studies which quantify the effects of kelp inclusion in formulated feeds. Furthermore, the physiological mechanisms by which kelp supplementation may positively influence abalone digestive physiology and growth are largely unknown. As the kelp supplement is comprised mostly of soluble fibres and abalone gut bacteria associated with macroalgae (and its fibrous polysaccharides) are known to play a key role in digestion, it was hypothesised that the kelp supplement influences the gut-bacterial community profiles of cultured abalone through prebiotic and other metabolic effects. The present thesis thus examined the effect of kelp supplementation on the performance of abalone (Haliotis midae) fed formulated feeds and explored the influence of a kelp supplement on the abalone gut microbiota and its function in the gastrointestinal tract. The key hypotheses of the study were that kelp supplementation in formulated feed: 1) enhances abalone growth; 2) causes a shift in abalone gut-bacterial community composition through a prebiotic-like effect; 3) may induce changes in crop morphology as a result of potential bacterial-associated increases in volatile short-chain fatty acids, and 4) alters digestive enzyme activities in the abalone gut through changes in bacterial-derived (exogenous) digestive enzymes. The growth-promoting efficacy of low-level kelp supplementation was tested by feeding isonitrogenous and isoenergetic experimental feeds containing 0.00 – 3.54 % kelp (dry mass) to sub-adult abalone (~43 mm shell length) for eight months under commercial farm conditions. The growth trial established that kelp supplementation (0.44 – 3.54 % of dry mass) promoted faster growth and improved feed conversion and protein efficiency ratios in cultured abalone compared to abalone fed the non-supplemented control diet, while there were no significant differences in growth for abalone fed the different kelp-supplemented diets (0.44, 0.88, 1.76 and 3.54 % of dry mass). Feed conversion and protein efficiency ratios displayed significant correlations with kelp level in the range of 0.00 – 3.54 % dry mass, and it is therefore recommended that kelp be included in the formulated feeds of cultured South African abalone at a rate of up to 3.54 % of dry mass. A kelp-supplemented (0.88 % dry weight inclusion) feed was fed to abalone under farm conditions to compare gut physiological parameters (crop morphology, digestive enzyme activities and the gut microbiota) in abalone against that of abalone fed an isonitrogenous and isoenergetic non-supplemented control feed. To establish if the observed higher abalone growth rates were related to improved gastrointestinal tract epithelium activity and integrity, as reflected by epithelial cell growth in response to potential changes in bacterial-derived short-chain fatty acid production, crop epithelial morphology was compared between abalone fed the kelp-supplemented and control feeds. Kelp supplementation did not induce any observable changes in crop epithelial cell height for farm-reared sub-adult abalone fed the experimental diets on-farm for seven weeks. This was attributed to the similar macronutrient compositions of kelp-supplemented and control diets and/ or the common diet history of experimental abalone from weaning to the initiation of the experiment. Digestive enzyme activity was compared between abalone fed a kelp-supplemented and a control feed during an on-farm feeding trial with sub-adult abalone. Gut samples were collected after seven weeks and colorimetric enzyme assays were performed for the polysaccharide-degrading enzymes amylase, alginate lyase, laminarinase and fucoidanase, and for acid protease, trypsin and chymotrypsin activity. Amylase and alginate lyase activities were relatively high, compared to the other enzymes. Polysaccharidase and acid protease activity levels did not differ significantly between abalone fed kelp-supplemented and control feeds, but a greater variability in enzyme activity levels was observed in abalone fed the control diet. It was hypothesised that this might be due to the kelp supplement promoting a more stable and less opportunistic gut-bacterial community than the control diet. Pooled gut samples of abalone fed the kelp-supplemented diet were used for proteomic analyses to identify the composition of enzyme proteins of both endogenous and exogenous origin in the abalone digestive system. The key polysaccharidases and proteases in the gut samples of kelp-supplemented formulated feed-fed abalone were all of abalone origin, whereas the bacterial enzymes were of the types that form part of intermediate reactions in metabolic pathways. The results suggested that bacterial enzymes play a different role to abalone endogenous enzymes in the digestion of formulated feed. While abalone enzymes appear to be the main degraders of carbohydrate and protein macromolecules, the profile of exogenous enzymes suggests that they perform bioconversions of smaller organic compounds. The profiles of gut-bacterial communities of farm-reared sub-adult abalone fed kelpsupplemented and control feeds on-farm for seven weeks were analysed with metagenomic pyrosequencing and DGGE analyses, using 16S rDNA-targeted amplified DNA. The results indicated a shift in gut-bacterial composition with a higher abundance of Mollicutes in abalone fed kelp-supplemented feed compared to those fed the control feed. DGGE band patterns displayed a greater within-group similarity in gut bacteria for abalone fed the kelpsupplemented diet and the presence of unique and variable bands for bacteria in the guts of abalone fed the control diet. It was concluded that when cultured abalone are fed kelpsupplemented formulated feeds, more stable gut bacterial communities are present compared to a more opportunistic gut-bacterial community in abalone fed non-supplemented feeds, and that the observed increase in Mollicutes could reflect the restoration of the abalone gut microbiota to a more natural state. The novel application of proteomics to abalone nutrition in the present study demonstrated that gut-bacterial enzymes may form part of many different metabolic pathways and suggests that the metabolism of the gut microbiota serves as an extension of the abalone’s digestive metabolism. Future studies should quantify the contribution of commensal gut-bacteria to cultured abalone nutrition by employing metabolomic studies to characterize the utilisation of bacterial-derived metabolites by the abalone host.
- Full Text:
- Date Issued: 2016
Gold nanoparticle–based colorimetric probes for dopamine detection
- Authors: Ngomane, Nokuthula
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4565 , http://hdl.handle.net/10962/d1021261
- Description: Colorimetric probes have become important tools in analysis and biomedical technology. This thesis reports on the development of such probes for the detection of dopamine (DA). Liquid and different solid state probes were developed utilizing un–functionalized gold nanoparticles (UF–AuNPs). The liquid state probe is based on the growth and aggregation of the UF–AuNPs in the presence of DA. Upon addition of the UF–AuNPs to various concentrations of DA, the shape, size and colour change results in spectral shifts from lower to higher wavelengths. The analyte can be easily monitored by the naked eye from 5.0 nM DA with a calculated limit of detection of 2.5 nM (3σ) under optimal pH. Ascorbic acid (AA) has a potential to interfere with DA detection in solution since it is often present in biological fluids, but in this case the interference was limited to solutions where its concentration was beyond 200 times greater than that of DA. Since most of the previously reported colorimetric probes, especially those for DA are solution based, the main focus of the thesis was in the development of a solid state based colorimetric probe in the form of nanofibre mats. To overcome the interference challenges experienced in the solution studies (the interference by high concentrations of AA), the suitability of molecularly imprinted polymers (MIPs) for the selective detection of DA was investigated. The results showed that the MIPs produced did not play a significant role in enhancing the selectivity towards DA. A probe composed of just the UF–AuNPs and Nylon–6 (UF–AuNPs + N6) was also developed. The UF–AuNPs were synthesized following an in situ reduction method. The probe was only selective to DA and insensitive to other catecholamines at physiological pH. Thus, the probe did not require any addition functionalities to achieve selectivity and sensitive to DA. The liquid state probe and the composite UF–AuNPs + N6 nanofibre probe were successfully applied to a whole blood sample and showed good selectivity towards DA. The simple, sensitive and selective probe could be an excellent alternative for on–site and immediate detection of DA without the use of instrumentation. For quantification of DA using the solid state probe, open–source software imageJ was used to assist in the analysis of the nanofibre colours. It was observed that the intensity of the colour increased with the increase in concentration of DA in a linear fashion. The use of imageJ can also be a great alternative where the colour changes are not so clear or for visually impaired people. The solid state probe developed can detect DA qualitatively and quantitatively. The work also forms a good foundation for development of such probes for other analyte.
- Full Text:
- Date Issued: 2016
- Authors: Ngomane, Nokuthula
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4565 , http://hdl.handle.net/10962/d1021261
- Description: Colorimetric probes have become important tools in analysis and biomedical technology. This thesis reports on the development of such probes for the detection of dopamine (DA). Liquid and different solid state probes were developed utilizing un–functionalized gold nanoparticles (UF–AuNPs). The liquid state probe is based on the growth and aggregation of the UF–AuNPs in the presence of DA. Upon addition of the UF–AuNPs to various concentrations of DA, the shape, size and colour change results in spectral shifts from lower to higher wavelengths. The analyte can be easily monitored by the naked eye from 5.0 nM DA with a calculated limit of detection of 2.5 nM (3σ) under optimal pH. Ascorbic acid (AA) has a potential to interfere with DA detection in solution since it is often present in biological fluids, but in this case the interference was limited to solutions where its concentration was beyond 200 times greater than that of DA. Since most of the previously reported colorimetric probes, especially those for DA are solution based, the main focus of the thesis was in the development of a solid state based colorimetric probe in the form of nanofibre mats. To overcome the interference challenges experienced in the solution studies (the interference by high concentrations of AA), the suitability of molecularly imprinted polymers (MIPs) for the selective detection of DA was investigated. The results showed that the MIPs produced did not play a significant role in enhancing the selectivity towards DA. A probe composed of just the UF–AuNPs and Nylon–6 (UF–AuNPs + N6) was also developed. The UF–AuNPs were synthesized following an in situ reduction method. The probe was only selective to DA and insensitive to other catecholamines at physiological pH. Thus, the probe did not require any addition functionalities to achieve selectivity and sensitive to DA. The liquid state probe and the composite UF–AuNPs + N6 nanofibre probe were successfully applied to a whole blood sample and showed good selectivity towards DA. The simple, sensitive and selective probe could be an excellent alternative for on–site and immediate detection of DA without the use of instrumentation. For quantification of DA using the solid state probe, open–source software imageJ was used to assist in the analysis of the nanofibre colours. It was observed that the intensity of the colour increased with the increase in concentration of DA in a linear fashion. The use of imageJ can also be a great alternative where the colour changes are not so clear or for visually impaired people. The solid state probe developed can detect DA qualitatively and quantitatively. The work also forms a good foundation for development of such probes for other analyte.
- Full Text:
- Date Issued: 2016
Exploring functionings and conversion factors in biodiversity teacher professional learning communities
- Tshiningayamwe, Sirkka Alina Nambashun
- Authors: Tshiningayamwe, Sirkka Alina Nambashun
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2080 , http://hdl.handle.net/10962/d1021313
- Description: The study explores the conversion factors, functionings (valued beings and doings), agency and structures in Professional Learning Communities (PLCs) for Life Sciences teachers’ biodiversity knowledge. The teachers’ valued beings and doings as well as conversion factors associated with these beings and doings were discussed within the conceptual framework of the capability approach using three PLCs in South Africa. Two PLCs were in the Eastern Cape Province (Grahamstown and Idutywa district), and one PLC was in the Western Cape (Cape Town) province. The PLCs involved in this study were course initiated and were positioned in the Fundisa for Change national teacher education programme. Fundisa for Change is a partnership programme that aims to enhance transformative environmental learning through teacher education. To illuminate constrained capabilities and how and to what extent the Life Sciences teachers’ empirical actions are related to these, the concepts of the capability approach were underlaboured with critical realism’s causal view of human action. A critical realist theory of causation was useful in explaining how the teachers’ valued beings and doings, conversion factors and capability sets can be partly accounted for via an understanding of underlying mechanisms that are generative of events and empirical experience. The study used a qualitative case study research methodology. Interviews, questionnaires, observations (of PLC activities), document reviews (of teachers’ portfolios of evidence, Fundisa for Change implementation plan, evaluation forms and resources materials, and policy documents) and reflection tools were used to collect data. Using the critical realism modes of inference (induction, abduction and retroduction), the data was analysed in two phases. Phase one analysis was primarily inductive and used thick descriptions (mainly in the form of quotes) to present and discuss the teachers’ valued beings and doings and associated conversion factors in the PLCs. This phase of analysis was abductive. The study reported four main functionings valued by teachers: subject content knowledge, teaching practices, assessment practices, and use of teaching and learning support materials. These valued functionings were discussed in light of the beings and doings in the PLCs and the underlying mechanisms related to teachers’ biodiversity teaching. Conversion factors that were associated with the teachers’ valued beings and doings in the PLCs were discussed in line with capability approach’s environmental, social and personal conversion factors. The study found that most of the conversion factors within the PLCs and the Fundisa for Change professional development programme (good facilitation, collaborative learning space, site where PLC activities happened, individual teachers’ capabilities, teaching and learning support materials and policy documents) were enablers to the teachers’ capabilities for biodiversity teaching, and thus enhanced teachers’ knowledge for biodiversity teaching. The study further found that teachers realised some of their achieved functionings in their actual teaching of biodiversity content in the Life Sciences curriculum, and that factors such as lack of resources, large class sizes, learners’ abilities and lack of interest among some teachers were amongst the factors that constrained teachers’ realisation of their achieved functionings in the PLCs. The study therefore revealed that if professional development programmes take account of underlying mechanisms and respond to teachers’ capabilities i.e. their valued functionings for biodiversity teaching in the Life Sciences curriculum, the professional development programmes can be an important conversion factor that enables the expansion of teachers’ capabilities (especially their biodiversity knowledge, pedagogical and assessment practice but also other capabilities) in ways that have the potential to reshape teachers’ classroom practices related to the teaching of biodiversity.
- Full Text:
- Date Issued: 2016
- Authors: Tshiningayamwe, Sirkka Alina Nambashun
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2080 , http://hdl.handle.net/10962/d1021313
- Description: The study explores the conversion factors, functionings (valued beings and doings), agency and structures in Professional Learning Communities (PLCs) for Life Sciences teachers’ biodiversity knowledge. The teachers’ valued beings and doings as well as conversion factors associated with these beings and doings were discussed within the conceptual framework of the capability approach using three PLCs in South Africa. Two PLCs were in the Eastern Cape Province (Grahamstown and Idutywa district), and one PLC was in the Western Cape (Cape Town) province. The PLCs involved in this study were course initiated and were positioned in the Fundisa for Change national teacher education programme. Fundisa for Change is a partnership programme that aims to enhance transformative environmental learning through teacher education. To illuminate constrained capabilities and how and to what extent the Life Sciences teachers’ empirical actions are related to these, the concepts of the capability approach were underlaboured with critical realism’s causal view of human action. A critical realist theory of causation was useful in explaining how the teachers’ valued beings and doings, conversion factors and capability sets can be partly accounted for via an understanding of underlying mechanisms that are generative of events and empirical experience. The study used a qualitative case study research methodology. Interviews, questionnaires, observations (of PLC activities), document reviews (of teachers’ portfolios of evidence, Fundisa for Change implementation plan, evaluation forms and resources materials, and policy documents) and reflection tools were used to collect data. Using the critical realism modes of inference (induction, abduction and retroduction), the data was analysed in two phases. Phase one analysis was primarily inductive and used thick descriptions (mainly in the form of quotes) to present and discuss the teachers’ valued beings and doings and associated conversion factors in the PLCs. This phase of analysis was abductive. The study reported four main functionings valued by teachers: subject content knowledge, teaching practices, assessment practices, and use of teaching and learning support materials. These valued functionings were discussed in light of the beings and doings in the PLCs and the underlying mechanisms related to teachers’ biodiversity teaching. Conversion factors that were associated with the teachers’ valued beings and doings in the PLCs were discussed in line with capability approach’s environmental, social and personal conversion factors. The study found that most of the conversion factors within the PLCs and the Fundisa for Change professional development programme (good facilitation, collaborative learning space, site where PLC activities happened, individual teachers’ capabilities, teaching and learning support materials and policy documents) were enablers to the teachers’ capabilities for biodiversity teaching, and thus enhanced teachers’ knowledge for biodiversity teaching. The study further found that teachers realised some of their achieved functionings in their actual teaching of biodiversity content in the Life Sciences curriculum, and that factors such as lack of resources, large class sizes, learners’ abilities and lack of interest among some teachers were amongst the factors that constrained teachers’ realisation of their achieved functionings in the PLCs. The study therefore revealed that if professional development programmes take account of underlying mechanisms and respond to teachers’ capabilities i.e. their valued functionings for biodiversity teaching in the Life Sciences curriculum, the professional development programmes can be an important conversion factor that enables the expansion of teachers’ capabilities (especially their biodiversity knowledge, pedagogical and assessment practice but also other capabilities) in ways that have the potential to reshape teachers’ classroom practices related to the teaching of biodiversity.
- Full Text:
- Date Issued: 2016
Selecting and augmenting a FOSS development and deployment environment for personalized video-oriented services in a Telco context
- Authors: Shibeshi, Zelalem Sintayehu
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/943 , vital:20005
- Description: The great demand for video services on the Internet is one contributing factor that led telecom companies to search for solutions to deliver innovative video services, using the different access technologies managed by them and leveraging the capacity of enforcing Quality of Service (QoS). One part of the solution was an infrastructure that guarantees QoS for these services, in the form of the IP Multimedia Subsystem (IMS) framework. The IMS framework was developed for delivering innovative multimedia services, but IMS alone does not provide the required services. This has led to further work in the area of multimedia service architectures. One noteworthy architecture is IPTV. IPTV is more than what its name implies, as it allows the development of various innovative video-oriented services and not just tv. When IPTV was introduced, many thought that it would bring back the revenue loss that telecom companies experienced to over-the-top (OTT) service providers. However, despite all its promises, the IPTV implementation has not shown as wide an uptake as one would expect. Although there could be various reasons for the slow penetration of IPTV, one reason could be the technical challenge that IPTV poses to service developers. One of the main reasons for the embarking of the research reported in this thesis was to identify and select free and open source software (FOSS) based platforms and augment them for easy development and deployment of video-oriented services. The thesis motivated how the IPTV architecture, with some modification, can be a good architecture to develop innovative video-oriented services. For a better understanding and investigate the issues of video-oriented service development on different platforms, we followed an incremental and iterative prototyping method. As a result, various video-oriented services were first developed and implementation-related issues were analyzed. This has helped us to identify problems that service developers face, including the requirement to utilize a number of protocols to develop an IPTV-based video-oriented service and the lack of a platform that provides a consistent programming interface to implement them all. The process also helped us to identify new uses cases through the process. As part of our selection process, we found that the Mobicents service development platform can be used as the basis for a good service development and deployment environment for video-oriented services. Mobicents is a Java-based service delivery platform for quick development, deployment and management of next generation network applications. Mobicents is a good choice because it provides a consistent programming interface and supports the various protocols needed in a consistent manner or an easy way to include the support for them. We used Mobicents to compose the environment that developers can use to build video-oriented services. Specifically we developed components and service building blocks that service developer can use to develop various innovative video-oriented services. During our research, we also identified various issues with regard to support from streaming servers in general and open source streaming servers in particular and also with the protocol they use. Specifically, we identified issues with Real Time Streaming Protocol (RTSP), a protocol specified as the media control protocol in the IPTV specification, and made proposals for solving them. We developed an RSTP proxy to augment the features lacking in the current streaming servers and implemented some of the features we proposed in it.
- Full Text:
- Date Issued: 2016
- Authors: Shibeshi, Zelalem Sintayehu
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/943 , vital:20005
- Description: The great demand for video services on the Internet is one contributing factor that led telecom companies to search for solutions to deliver innovative video services, using the different access technologies managed by them and leveraging the capacity of enforcing Quality of Service (QoS). One part of the solution was an infrastructure that guarantees QoS for these services, in the form of the IP Multimedia Subsystem (IMS) framework. The IMS framework was developed for delivering innovative multimedia services, but IMS alone does not provide the required services. This has led to further work in the area of multimedia service architectures. One noteworthy architecture is IPTV. IPTV is more than what its name implies, as it allows the development of various innovative video-oriented services and not just tv. When IPTV was introduced, many thought that it would bring back the revenue loss that telecom companies experienced to over-the-top (OTT) service providers. However, despite all its promises, the IPTV implementation has not shown as wide an uptake as one would expect. Although there could be various reasons for the slow penetration of IPTV, one reason could be the technical challenge that IPTV poses to service developers. One of the main reasons for the embarking of the research reported in this thesis was to identify and select free and open source software (FOSS) based platforms and augment them for easy development and deployment of video-oriented services. The thesis motivated how the IPTV architecture, with some modification, can be a good architecture to develop innovative video-oriented services. For a better understanding and investigate the issues of video-oriented service development on different platforms, we followed an incremental and iterative prototyping method. As a result, various video-oriented services were first developed and implementation-related issues were analyzed. This has helped us to identify problems that service developers face, including the requirement to utilize a number of protocols to develop an IPTV-based video-oriented service and the lack of a platform that provides a consistent programming interface to implement them all. The process also helped us to identify new uses cases through the process. As part of our selection process, we found that the Mobicents service development platform can be used as the basis for a good service development and deployment environment for video-oriented services. Mobicents is a Java-based service delivery platform for quick development, deployment and management of next generation network applications. Mobicents is a good choice because it provides a consistent programming interface and supports the various protocols needed in a consistent manner or an easy way to include the support for them. We used Mobicents to compose the environment that developers can use to build video-oriented services. Specifically we developed components and service building blocks that service developer can use to develop various innovative video-oriented services. During our research, we also identified various issues with regard to support from streaming servers in general and open source streaming servers in particular and also with the protocol they use. Specifically, we identified issues with Real Time Streaming Protocol (RTSP), a protocol specified as the media control protocol in the IPTV specification, and made proposals for solving them. We developed an RSTP proxy to augment the features lacking in the current streaming servers and implemented some of the features we proposed in it.
- Full Text:
- Date Issued: 2016
Nanocomposites of carbon nanomaterials and metallophthalocyanines : applications towards electrocatalysis
- Authors: Nyoni, Stephen
- Date: 2016
- Subjects: Nanocomposites (Materials) , Nanostructured materials , Electrocatalysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4561 , http://hdl.handle.net/10962/d1020846
- Description: Nanohybrid materials have been prepared and examined for their electrocatalytic activity. The nanocomposites have been prepared from carbon nanomaterials (multiwalled carbon nanotubes (MWCNTs) and graphene nanosheets), cadmium selenide quantum dots and metallophthalocyanines (MPcs). The MPcs used in this work are cobalt tetraamino-phthalocyanine (CoTAPc) and tetra (4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt (II)) (CoPyPc). Their activity has also been explored in different forms; polymeric MPcs, iodine doped MPcs and covalently linked MPcs. The premixed drop-dry, sequential drop-dry and electropolymerisation electrode modification techniques were used to prepare nanocomposite catalysts on the glassy carbon electrode (GCE) surface. The sequential drop dry technique for MPc and MWCNTs gave better catalytic responses in terms of limit of detection, catalytic and electron transfer rate constants relative to the premixed. MWCNTs and CdSe-QDs have been used as intercalating agents to reduce restacking of graphene nanosheets during nanocomposite preparation. Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for electrochemical characterization modified GCE. X-ray photoelectron spectroscopy, X-ray diffractometry, transmission electron microscopy, scanning electron microscopy, infra-red spectroscopy, Raman spectroscopy were used to explore surface functionalities, morphology and topography of the nanocomposites. Electrocatalytic activity and possible applications of the modified electrodes were tested using oxygen reduction reaction, l-cysteine oxidation and paraquat reduction. Activity of nanocomposites was found superior over individual nanomaterials in these applications.
- Full Text:
- Date Issued: 2016
- Authors: Nyoni, Stephen
- Date: 2016
- Subjects: Nanocomposites (Materials) , Nanostructured materials , Electrocatalysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4561 , http://hdl.handle.net/10962/d1020846
- Description: Nanohybrid materials have been prepared and examined for their electrocatalytic activity. The nanocomposites have been prepared from carbon nanomaterials (multiwalled carbon nanotubes (MWCNTs) and graphene nanosheets), cadmium selenide quantum dots and metallophthalocyanines (MPcs). The MPcs used in this work are cobalt tetraamino-phthalocyanine (CoTAPc) and tetra (4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt (II)) (CoPyPc). Their activity has also been explored in different forms; polymeric MPcs, iodine doped MPcs and covalently linked MPcs. The premixed drop-dry, sequential drop-dry and electropolymerisation electrode modification techniques were used to prepare nanocomposite catalysts on the glassy carbon electrode (GCE) surface. The sequential drop dry technique for MPc and MWCNTs gave better catalytic responses in terms of limit of detection, catalytic and electron transfer rate constants relative to the premixed. MWCNTs and CdSe-QDs have been used as intercalating agents to reduce restacking of graphene nanosheets during nanocomposite preparation. Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for electrochemical characterization modified GCE. X-ray photoelectron spectroscopy, X-ray diffractometry, transmission electron microscopy, scanning electron microscopy, infra-red spectroscopy, Raman spectroscopy were used to explore surface functionalities, morphology and topography of the nanocomposites. Electrocatalytic activity and possible applications of the modified electrodes were tested using oxygen reduction reaction, l-cysteine oxidation and paraquat reduction. Activity of nanocomposites was found superior over individual nanomaterials in these applications.
- Full Text:
- Date Issued: 2016
An evaluation of sampling and statistical methods for long-term monitoring of subtidal reef fishes : a case study of Tsitsikamma National Park marine protected area
- Authors: Parker, Denham
- Date: 2016
- Subjects: Reef fishes -- South Africa -- Monitoring , Tsitsikamma National Park (South Africa)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5385 , http://hdl.handle.net/10962/d1019991
- Description: Tsitsikamma National Park (TNP) possesses the oldest (established 1954), and one of the largest (350 km2) ‘no-take’ marine protected areas (MPA) in South Africa. A long-term monitoring (LTM) programme to observe the subtidal reef fishes in the TNP MPA was established in 2007. To date, 243 angling replicates have been completed, and a total of 2,751 fish belonging to 41 different species have been caught and released. In an era of unprecedented global biodiversity loss, data that can be used to monitor ecosystems and gauge changes in biodiversity through time are essential. This thesis aims to improve the methodological and statistical processes currently available for LTM of subtidal reef fish by providing an evaluation of the TNP MPA LTM programme. Angling data revealed definitive spatial structuring, in the form of spatial autocorrelation, and a shift in viewing spatial dependency as a statistical obstacle to a source of ecological information created a new avenue of data inference. Species-specific distribution maps identified localized habitat as the main predictor variable for species abundance, emphasizing the need for accurate a priori bathymetric information for subtidal monitoring. ‘Random forest’ analyses confirmed spatial variables are more important than temporal variables in predicting species abundance. The effectiveness of Generalized Linear Mixed Models (GAMMs) to account for spatial autocorrelation was highlighted, and evidence that disregarding spatial dependencies in temporal analyses can produce erroneous results was illustrated in the case of dageraad (Chrysoblephus cristiceps). Correlograms indicated that the current sampling strategy produced spatially redundant data and the sampling unit size (150 m2) could be doubled to optimize sampling. Temporal analyses demonstrated that after 50 years of ‘no take’ protection the TNP MPA ichthyofauna exhibits a high level of stability. Species-specific size structure was also found to be highly stable. Dageraad was the only species to exhibit a definitive temporal trend in their size structure, which was attributed to recruitment variation and the possibility that large individuals may migrate out of the study area. The inadequacy of angling as a method for monitoring a broad spectrum of the fish species was highlighted, particularly due to its selectivity towards large predators. As a result, a new sampling technique known as Stereo Baited Remote Underwater Videos (stereo-BRUVs) was introduced to the LTM programme in 2013. Stereo-BRUVs enabled sampling of 2640 fish belonging to 52 different species, from 57 samples collected in less than two years. A comparison of the sampling methods concluded that, compared to angling, stereo-BRUVs provide a superior technique that can survey a significantly larger proportion of the ichthyofauna with minimal length-selectivity biases. In addition, stereo-BRUVs possess a higher statistical power to detect changes in population abundance. However, a potential bias in the form of ‘hyperstability’ in sites with unusually high fish densities was identified as a possible flaw when using stereo-BRUVs. In an attempt to provide a more rigorous method evaluation, simulation testing was employed to assess the ability of angling and stereo-BRUVs to accurately describe a decreasing population. The advantage of this approach is that the simulated population abundances are known, so that each sampling method can be tested in terms of how well it tracks known abundance trends. The study established that stereo- BRUVs provided more accurate data when describing a distinct population decline of roman (Chrysoblephus laticeps) over 10- and 20-year periods. In addition, spawner-biomass was found to be a more accurate population estimate than relative abundance estimates (CPUE and MaxN) due to the inclusion of population size structure information, highlighting the importance of length-frequency data. The study illustrated that an evaluation framework that utilizes simulation testing has the potential to optimize LTM sampling procedures by addressing a number of methodological questions. This includes developing a procedure that aligns data collected from different sampling methods by applying correction factors, thus ensuring LTM programmes are able to adapt sampling strategies without losing data continuity.
- Full Text:
- Date Issued: 2016
- Authors: Parker, Denham
- Date: 2016
- Subjects: Reef fishes -- South Africa -- Monitoring , Tsitsikamma National Park (South Africa)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5385 , http://hdl.handle.net/10962/d1019991
- Description: Tsitsikamma National Park (TNP) possesses the oldest (established 1954), and one of the largest (350 km2) ‘no-take’ marine protected areas (MPA) in South Africa. A long-term monitoring (LTM) programme to observe the subtidal reef fishes in the TNP MPA was established in 2007. To date, 243 angling replicates have been completed, and a total of 2,751 fish belonging to 41 different species have been caught and released. In an era of unprecedented global biodiversity loss, data that can be used to monitor ecosystems and gauge changes in biodiversity through time are essential. This thesis aims to improve the methodological and statistical processes currently available for LTM of subtidal reef fish by providing an evaluation of the TNP MPA LTM programme. Angling data revealed definitive spatial structuring, in the form of spatial autocorrelation, and a shift in viewing spatial dependency as a statistical obstacle to a source of ecological information created a new avenue of data inference. Species-specific distribution maps identified localized habitat as the main predictor variable for species abundance, emphasizing the need for accurate a priori bathymetric information for subtidal monitoring. ‘Random forest’ analyses confirmed spatial variables are more important than temporal variables in predicting species abundance. The effectiveness of Generalized Linear Mixed Models (GAMMs) to account for spatial autocorrelation was highlighted, and evidence that disregarding spatial dependencies in temporal analyses can produce erroneous results was illustrated in the case of dageraad (Chrysoblephus cristiceps). Correlograms indicated that the current sampling strategy produced spatially redundant data and the sampling unit size (150 m2) could be doubled to optimize sampling. Temporal analyses demonstrated that after 50 years of ‘no take’ protection the TNP MPA ichthyofauna exhibits a high level of stability. Species-specific size structure was also found to be highly stable. Dageraad was the only species to exhibit a definitive temporal trend in their size structure, which was attributed to recruitment variation and the possibility that large individuals may migrate out of the study area. The inadequacy of angling as a method for monitoring a broad spectrum of the fish species was highlighted, particularly due to its selectivity towards large predators. As a result, a new sampling technique known as Stereo Baited Remote Underwater Videos (stereo-BRUVs) was introduced to the LTM programme in 2013. Stereo-BRUVs enabled sampling of 2640 fish belonging to 52 different species, from 57 samples collected in less than two years. A comparison of the sampling methods concluded that, compared to angling, stereo-BRUVs provide a superior technique that can survey a significantly larger proportion of the ichthyofauna with minimal length-selectivity biases. In addition, stereo-BRUVs possess a higher statistical power to detect changes in population abundance. However, a potential bias in the form of ‘hyperstability’ in sites with unusually high fish densities was identified as a possible flaw when using stereo-BRUVs. In an attempt to provide a more rigorous method evaluation, simulation testing was employed to assess the ability of angling and stereo-BRUVs to accurately describe a decreasing population. The advantage of this approach is that the simulated population abundances are known, so that each sampling method can be tested in terms of how well it tracks known abundance trends. The study established that stereo- BRUVs provided more accurate data when describing a distinct population decline of roman (Chrysoblephus laticeps) over 10- and 20-year periods. In addition, spawner-biomass was found to be a more accurate population estimate than relative abundance estimates (CPUE and MaxN) due to the inclusion of population size structure information, highlighting the importance of length-frequency data. The study illustrated that an evaluation framework that utilizes simulation testing has the potential to optimize LTM sampling procedures by addressing a number of methodological questions. This includes developing a procedure that aligns data collected from different sampling methods by applying correction factors, thus ensuring LTM programmes are able to adapt sampling strategies without losing data continuity.
- Full Text:
- Date Issued: 2016
The Contribution of fruit from trees to improve household nutritional security in the context of deforestation in Cameroon
- Tata epse Ngome, Precillia Ijang
- Authors: Tata epse Ngome, Precillia Ijang
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/793 , vital:19991
- Description: Cameroon needs healthy citizens to archive emergence by 2035. Malnutrition and undernourishment is the highest burden in the World in recent times and a silent crisis facing most rural communities in forest areas of Cameroon. Its abstruseness makes extremely fragile political, social and economic planning to foster development in such areas. Therefore, it is time we bring appropriate understanding and new strategies on unpacking the complexities of food and nutritional security and define practical solutions to food insecurity. Working in the context of increasing deforestation, this thesis brings evidence on the situation of household food insecurity (FIS) access experience in forest areas which is not reported in current discussions at the national level. It further investigates the knowledge and awareness of households on the availability, accessibility, utilisation, vulnerability and consumption of nutrient rich food items using the example of fruits from trees. Thus, the aim of this research was to investigate strategies for addressing household FIS through increased domestic supply and consumption of fruits from trees in the context of deforestation in Cameroon. Data were collected through four rounds of structured interviews completed between August 2013 and October 2014. Analysis was done using simple citations and ordering, Principal Component Analysis (PCA), Likert scale, χ2-test of association and Cramer's V coefficient to test the strength of the association and means and ANOVA. The HFIAS approach used to determine household FIS. Only 1% of the population were food secure and the moderately deforested zone showed the worst trends in food insecurity. Therefore, the effect of deforestation was nuanced. Diverse fruit trees were registered. Households said they required fruits only 2.4 ± 1.5 times per week. Recently, the intake of 400 g of fruit per person per day for good health was announced as a priority of international recognition. However, households were not aware of the importance and frequency of fruit consumption with less than 50% of households eating fruits daily during the harvesting season. Fruit tree nurseries where scarce and seeds where obtained from local sources. Fruit tree diseases where rampant and up to 50% harvest lost was registered for some fruits species. This study has shown that food availability does not necessarily mean adequate food intake. Three opinions about fruit trees and the prevalence of food insecurity in Cameroon has been raised in this thesis. First, there is ineffectiveness in the eradication of FIS because even in agricultural conducive environments, hunger and food insecurity are still prevalent at high rates. Therefore, effective and efficient targeting of food insecured groups need to be promoted in all clusters of the population. Secondly, the national nutrition program is neglecting sensitisation on food consumption patterns and therefore people are not making use of nutrient rich foods even when this maybe found around their environments - taking the case of fruits from trees. Thus, very few people ate fruits and at irregular frequencies of consumption. Thus, there is need to design special campaign programs to promote the consumption of fruits from trees. Thirdly, the word-of-mouth or neighbour-to-neighbour dissemination approach on fruit trees planting has not been efficient across communities. As such nurseries where scarce and people obtained fruit trees plants from natural regeneration or found them on the field when establishing the field. Therefore, in this research, it is postulated that no matter the nature of efforts and level of intervention, what is certain is that addressing FIS requires effective targeting of the vulnerable population and the implementation of novel and practical approaches on promoting access to and consumption of fruits in the right frequencies. This research further revealed that poor eating habits was a problem and lack of knowledge about the frequency and intake of nutrient rich food was serious. For instance, people were not aware on the recommended frequency of fruit consumption and people ate infested fruit while reserving the healthy ones for sale. This is the trap of the food insecurity problem in some regions – knowledge about foods and ways of food utilisation. This is neither a problem of availability nor accessibility, but rather a problem of lack of knowledge and lack of sensitisation. From FAO reports on the state of food insecurity in the world and other studies of food intake in most developing nation, poor food consumption is a global problem in most poor regions and even in rich areas affected by obesity. Thus, there is a need to establish a high level policy framework maybe in the form of a convention or an intergovernmental panel at the level of the United Nations and/or the African Union on ‘reducing malnutrition in all its forms (rates, drivers and consequences on human health and the environment)’. This structure will promote setting priorities, strategies, monitoring on peoples eating habits, setting nutritional standards, and principles and indicators for observing under nutrition, over nutrition and associated problems within all population strata.
- Full Text:
- Date Issued: 2016
- Authors: Tata epse Ngome, Precillia Ijang
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/793 , vital:19991
- Description: Cameroon needs healthy citizens to archive emergence by 2035. Malnutrition and undernourishment is the highest burden in the World in recent times and a silent crisis facing most rural communities in forest areas of Cameroon. Its abstruseness makes extremely fragile political, social and economic planning to foster development in such areas. Therefore, it is time we bring appropriate understanding and new strategies on unpacking the complexities of food and nutritional security and define practical solutions to food insecurity. Working in the context of increasing deforestation, this thesis brings evidence on the situation of household food insecurity (FIS) access experience in forest areas which is not reported in current discussions at the national level. It further investigates the knowledge and awareness of households on the availability, accessibility, utilisation, vulnerability and consumption of nutrient rich food items using the example of fruits from trees. Thus, the aim of this research was to investigate strategies for addressing household FIS through increased domestic supply and consumption of fruits from trees in the context of deforestation in Cameroon. Data were collected through four rounds of structured interviews completed between August 2013 and October 2014. Analysis was done using simple citations and ordering, Principal Component Analysis (PCA), Likert scale, χ2-test of association and Cramer's V coefficient to test the strength of the association and means and ANOVA. The HFIAS approach used to determine household FIS. Only 1% of the population were food secure and the moderately deforested zone showed the worst trends in food insecurity. Therefore, the effect of deforestation was nuanced. Diverse fruit trees were registered. Households said they required fruits only 2.4 ± 1.5 times per week. Recently, the intake of 400 g of fruit per person per day for good health was announced as a priority of international recognition. However, households were not aware of the importance and frequency of fruit consumption with less than 50% of households eating fruits daily during the harvesting season. Fruit tree nurseries where scarce and seeds where obtained from local sources. Fruit tree diseases where rampant and up to 50% harvest lost was registered for some fruits species. This study has shown that food availability does not necessarily mean adequate food intake. Three opinions about fruit trees and the prevalence of food insecurity in Cameroon has been raised in this thesis. First, there is ineffectiveness in the eradication of FIS because even in agricultural conducive environments, hunger and food insecurity are still prevalent at high rates. Therefore, effective and efficient targeting of food insecured groups need to be promoted in all clusters of the population. Secondly, the national nutrition program is neglecting sensitisation on food consumption patterns and therefore people are not making use of nutrient rich foods even when this maybe found around their environments - taking the case of fruits from trees. Thus, very few people ate fruits and at irregular frequencies of consumption. Thus, there is need to design special campaign programs to promote the consumption of fruits from trees. Thirdly, the word-of-mouth or neighbour-to-neighbour dissemination approach on fruit trees planting has not been efficient across communities. As such nurseries where scarce and people obtained fruit trees plants from natural regeneration or found them on the field when establishing the field. Therefore, in this research, it is postulated that no matter the nature of efforts and level of intervention, what is certain is that addressing FIS requires effective targeting of the vulnerable population and the implementation of novel and practical approaches on promoting access to and consumption of fruits in the right frequencies. This research further revealed that poor eating habits was a problem and lack of knowledge about the frequency and intake of nutrient rich food was serious. For instance, people were not aware on the recommended frequency of fruit consumption and people ate infested fruit while reserving the healthy ones for sale. This is the trap of the food insecurity problem in some regions – knowledge about foods and ways of food utilisation. This is neither a problem of availability nor accessibility, but rather a problem of lack of knowledge and lack of sensitisation. From FAO reports on the state of food insecurity in the world and other studies of food intake in most developing nation, poor food consumption is a global problem in most poor regions and even in rich areas affected by obesity. Thus, there is a need to establish a high level policy framework maybe in the form of a convention or an intergovernmental panel at the level of the United Nations and/or the African Union on ‘reducing malnutrition in all its forms (rates, drivers and consequences on human health and the environment)’. This structure will promote setting priorities, strategies, monitoring on peoples eating habits, setting nutritional standards, and principles and indicators for observing under nutrition, over nutrition and associated problems within all population strata.
- Full Text:
- Date Issued: 2016
Life history of the maritime platygastrid Echthrodesis lamorali Masner 1968 (Hymenoptera: Platygastridae: Scelioninae)
- Authors: Owen, Candice Ann
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/837 , vital:19995 , 10.21504/10962/837
- Description: Echthrodesis lamorali Masner 1968 (Hymenoptera: Platygastridae, Scelioninae) is an intertidal parasitoid wasp that uses the eggs of the maritime spider, Desis formidabilis O.P. Cambridge 1890 (Araneae: Desidae), as a host. This species is one of only three known maritime parasitoids globally, and is the only known spider egg parasitoid that attacks its host within the intertidal region in southern Africa. Originally described from ‘The Island’, Kommetjie (Western Cape, South Africa), this shore was the only known locality of the species at the commencement of this thesis. Furthermore, the extent of the parasitism pressure the wasp exerts on D. formidabilis was largely unknown, along with its basic biology (drivers of its broad-scale and fine-scale distribution patterns; parasitism incidence; and sex ratios) and morphological and physiological adaptations for living within the frequently saltwater-inundated environment. This thesis unravelled these aspects, as well as experimentally provided data for many components of the life history of E. lamorali that had only been hypothesized by other authors, at a variety of scales, from the country-wide ecosystem, to single shores, and finally to the scale of the individual. While the distribution of E. lamorali was found to be much wider than previously thought, it remained restricted to the shores of the Cape Peninsula (Western Cape, South Africa). The host spiders were located throughout a much wider distributional range than the wasp, from East London in the east to the Peninsula, but some behavioural and morphological differences were found between those within and outside of the range of the parasitoid, suggesting range-limitation imposed by the host on E. lamorali. This limitation may be strengthened by the general lack of suitable shore types within the close vicinity of the Peninsula. Modelling using macro-climatic conditions suggested that maximum temperatures and humidities were also largely limiting to E. lamorali, although these patterns were not observable in the micro-climates in which the species survives. The wasp populations and spiders within the range of E. lamorali as identified in Chapter 2 were assessed to determine any preferences for local conditions, including location along the Peninsula, nesting sites and intertidal zones within single shores, using AICc modelling, which detected parasitism patterns in D. formidabilis and E. lamorali populations, as well as the sex ratios in the latter species. The models showed that the spider population size and distribution was more influenced by bottom-up factors such as abiotic components of the shore than by parasitism, which only showed density dependence with the host at certain scales. Both host and parasitoid populations illustrated a preference for the middle zone on single shores. Observed spider nest characteristics suggested opportunistic nesting behaviour in the species, although preference was shown for construction along an east-west orientation and in locations with low sun exposure. Along with larger population sizes on the west coast over the east coast (not reflected by E. lamorali), these observations suggest that D. formidabilis prefers cooler environments. Spider brood success was 50% in unparasitized egg-sacs, but this figure halved when E. lamorali gained access to the eggs (of which 100% within a single compartment were parasitized each time). Encapsulation of the embryo was found to be positively correlated with parasitism, indicating some form of host resistance. Resultant parasitoid broods illustrated a strong female bias in the species, as is common for this group of insects. The life history of E. lamorali was then assessed at a smaller scale, that of the individual. Scanning electron microscopy of whole E. lamorali specimens and light microscopy of sectioned specimens demonstrated no morphological adaptations in the trachea and spiracles to cope with saltwater inundation. On the other hand, respirometry experiments categorically demonstrated that the species copes with inundation through the formation of a physical gill over the full habitus, and the induction of a state of torpor to reduce metabolic needs, when submerged. This precludes the need for any further morphological adaptations. Determination of the wasp’s critical thermal tolerance illustrated a wide temperature range with a particularly cold lower limit of -1.1ºC ± 0.16, suggesting the presence of related genera or ancestors in much colder environments. With a much broader distribution than previously thought, and the inclusion of the distributional range of E. lamorali within the Table Mountain National Park, this species is being effectively conserved and managed through the umbrella-conservation of the park. Links to the host proved to vary at differing scales, proving the need for scale considerations to be included in other similar biological and ecological studies. Finally, the species showed physiological adaptation to its intertidal existence. Echthrodesis lamorali, the only discovered maritime spider egg parasitoid in Southern Africa, displayed unusual characteristics at every scale of its life history and as such, warrants further investigation.
- Full Text:
- Date Issued: 2016
- Authors: Owen, Candice Ann
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/837 , vital:19995 , 10.21504/10962/837
- Description: Echthrodesis lamorali Masner 1968 (Hymenoptera: Platygastridae, Scelioninae) is an intertidal parasitoid wasp that uses the eggs of the maritime spider, Desis formidabilis O.P. Cambridge 1890 (Araneae: Desidae), as a host. This species is one of only three known maritime parasitoids globally, and is the only known spider egg parasitoid that attacks its host within the intertidal region in southern Africa. Originally described from ‘The Island’, Kommetjie (Western Cape, South Africa), this shore was the only known locality of the species at the commencement of this thesis. Furthermore, the extent of the parasitism pressure the wasp exerts on D. formidabilis was largely unknown, along with its basic biology (drivers of its broad-scale and fine-scale distribution patterns; parasitism incidence; and sex ratios) and morphological and physiological adaptations for living within the frequently saltwater-inundated environment. This thesis unravelled these aspects, as well as experimentally provided data for many components of the life history of E. lamorali that had only been hypothesized by other authors, at a variety of scales, from the country-wide ecosystem, to single shores, and finally to the scale of the individual. While the distribution of E. lamorali was found to be much wider than previously thought, it remained restricted to the shores of the Cape Peninsula (Western Cape, South Africa). The host spiders were located throughout a much wider distributional range than the wasp, from East London in the east to the Peninsula, but some behavioural and morphological differences were found between those within and outside of the range of the parasitoid, suggesting range-limitation imposed by the host on E. lamorali. This limitation may be strengthened by the general lack of suitable shore types within the close vicinity of the Peninsula. Modelling using macro-climatic conditions suggested that maximum temperatures and humidities were also largely limiting to E. lamorali, although these patterns were not observable in the micro-climates in which the species survives. The wasp populations and spiders within the range of E. lamorali as identified in Chapter 2 were assessed to determine any preferences for local conditions, including location along the Peninsula, nesting sites and intertidal zones within single shores, using AICc modelling, which detected parasitism patterns in D. formidabilis and E. lamorali populations, as well as the sex ratios in the latter species. The models showed that the spider population size and distribution was more influenced by bottom-up factors such as abiotic components of the shore than by parasitism, which only showed density dependence with the host at certain scales. Both host and parasitoid populations illustrated a preference for the middle zone on single shores. Observed spider nest characteristics suggested opportunistic nesting behaviour in the species, although preference was shown for construction along an east-west orientation and in locations with low sun exposure. Along with larger population sizes on the west coast over the east coast (not reflected by E. lamorali), these observations suggest that D. formidabilis prefers cooler environments. Spider brood success was 50% in unparasitized egg-sacs, but this figure halved when E. lamorali gained access to the eggs (of which 100% within a single compartment were parasitized each time). Encapsulation of the embryo was found to be positively correlated with parasitism, indicating some form of host resistance. Resultant parasitoid broods illustrated a strong female bias in the species, as is common for this group of insects. The life history of E. lamorali was then assessed at a smaller scale, that of the individual. Scanning electron microscopy of whole E. lamorali specimens and light microscopy of sectioned specimens demonstrated no morphological adaptations in the trachea and spiracles to cope with saltwater inundation. On the other hand, respirometry experiments categorically demonstrated that the species copes with inundation through the formation of a physical gill over the full habitus, and the induction of a state of torpor to reduce metabolic needs, when submerged. This precludes the need for any further morphological adaptations. Determination of the wasp’s critical thermal tolerance illustrated a wide temperature range with a particularly cold lower limit of -1.1ºC ± 0.16, suggesting the presence of related genera or ancestors in much colder environments. With a much broader distribution than previously thought, and the inclusion of the distributional range of E. lamorali within the Table Mountain National Park, this species is being effectively conserved and managed through the umbrella-conservation of the park. Links to the host proved to vary at differing scales, proving the need for scale considerations to be included in other similar biological and ecological studies. Finally, the species showed physiological adaptation to its intertidal existence. Echthrodesis lamorali, the only discovered maritime spider egg parasitoid in Southern Africa, displayed unusual characteristics at every scale of its life history and as such, warrants further investigation.
- Full Text:
- Date Issued: 2016
Land-use effects on mammal communities in the Fish-Kowie corridor, Eastern Cape, South Africa, with particular reference to carnivores
- Authors: Kok, Armand du Preez
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/561 , vital:19970
- Description: Human population growth is causing an increase in habitat transformation on a global scale, and this transformation is driven by changes in land-use practices. One consequence of habitat transformation is the negative effect it can have on mammal communities, especially carnivores. Carnivores are important components of ecosystems as they play an essential structuring role, but also often come into conflict with people. I studied the impact of land-use on mammalian diversity, the attitudes of landowners/managers towards carnivores, the distribution of carnivores, and the interactions among carnivore species in the Fish-Kowie corridor (FKC), an area of conservation concern, in the Eastern Cape, South Africa. Livestock and game farming are the two dominant land-use types in the FKC. Carnivore distribution data were collected between 2012 and 2014 using a robust camera trap survey that consisted of 432 camera stations (216 on livestock and 216 on game farms). In addition, the attitudes of 55 landowners/managers were assessed using semi- structured questionnaire interviews that were conducted in person. My results revealed that mammal diversity was similar on the two land-use types. However, individual species differed in their distribution on the two land-use types. In general, both livestock and game farmers had negative attitudes towards carnivores in the FKC, due to their depredation of valuable livestock and game species. Black-backed jackals (Canis mesomelas), caracals (Caracal caracal), leopards (Panthera pardus), and brown hyaenas (Parahyaena brunnea) were considered the most problematic carnivores, but sensitivity to land-use varied among these four species. Black- backed jackals had the highest occupancy rates of all four predators and were 3.8 times more likely to occupy sites on game farms compared to livestock farms. By contrast, leopards and brown hyaenas were only detected on game farms, and caracals did not appear to be sensitive to the effects of land-use. In general, the interactions among carnivores were weak and were likely driven by carnivore diversity, resource partitioning, and anthropogenic pressures. While there were many subtle differences in the distribution of mammal species and human attitudes towards wildlife on livestock and game farms in the FKC, there were also many similarities. My study has produced results that can be used by the FKC community to better understand how mammals and humans interact across the landscape, information that will ultimately contribute to future conservation planning in the area.
- Full Text:
- Date Issued: 2016
- Authors: Kok, Armand du Preez
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/561 , vital:19970
- Description: Human population growth is causing an increase in habitat transformation on a global scale, and this transformation is driven by changes in land-use practices. One consequence of habitat transformation is the negative effect it can have on mammal communities, especially carnivores. Carnivores are important components of ecosystems as they play an essential structuring role, but also often come into conflict with people. I studied the impact of land-use on mammalian diversity, the attitudes of landowners/managers towards carnivores, the distribution of carnivores, and the interactions among carnivore species in the Fish-Kowie corridor (FKC), an area of conservation concern, in the Eastern Cape, South Africa. Livestock and game farming are the two dominant land-use types in the FKC. Carnivore distribution data were collected between 2012 and 2014 using a robust camera trap survey that consisted of 432 camera stations (216 on livestock and 216 on game farms). In addition, the attitudes of 55 landowners/managers were assessed using semi- structured questionnaire interviews that were conducted in person. My results revealed that mammal diversity was similar on the two land-use types. However, individual species differed in their distribution on the two land-use types. In general, both livestock and game farmers had negative attitudes towards carnivores in the FKC, due to their depredation of valuable livestock and game species. Black-backed jackals (Canis mesomelas), caracals (Caracal caracal), leopards (Panthera pardus), and brown hyaenas (Parahyaena brunnea) were considered the most problematic carnivores, but sensitivity to land-use varied among these four species. Black- backed jackals had the highest occupancy rates of all four predators and were 3.8 times more likely to occupy sites on game farms compared to livestock farms. By contrast, leopards and brown hyaenas were only detected on game farms, and caracals did not appear to be sensitive to the effects of land-use. In general, the interactions among carnivores were weak and were likely driven by carnivore diversity, resource partitioning, and anthropogenic pressures. While there were many subtle differences in the distribution of mammal species and human attitudes towards wildlife on livestock and game farms in the FKC, there were also many similarities. My study has produced results that can be used by the FKC community to better understand how mammals and humans interact across the landscape, information that will ultimately contribute to future conservation planning in the area.
- Full Text:
- Date Issued: 2016
Financial characteristics of the nonprofit organisation: theory and evidence for the assessment of the financial condition of South African public universities
- Authors: Bunting, Mark Bevan
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:923 , http://hdl.handle.net/10962/d1021298 , http://orcid.org/0000-0002-3392-554X
- Description: In this thesis, an analytical framework is developed for the assessment of the financial condition of South African public universities. Foundational constructs of nonprofit economics are applied in the consideration of financial theories of nonprofit organisations in general, and public universities in particular. From this review, a number of hypotheses are developed. Each of these specifies a positive or negative association between a university's financial condition and a particular dimension of its assets, liabilities, equity, revenues, expenses and surplus. From the nonprofit financial analysis literature, ratios and indicators relevant to these hypotheses are selected. Audited data from the annual financial statements of the universities for the seven year period 2007 to 2013 are substantially transformed in mitigation of failures in accounting, auditing and accountability. The adjusted accounting numbers are used to calculate the financial indicators applicable to each university. Exploratory factor analysis is implemented to categorise and organise this large indicator set on the basis of identified associations with a smaller number of factors. It is found that the financial condition of South African public universities is defined by two broad financial characteristics, capital and revenue. Assessment of the capital dimension is informed by a focus on institutional equity, with particular emphasis on expendable equity and its proportionate relationships with surplus, total capital, and total expenses. The revenue dimension is appropriately evaluated in the context of a comparative and interactive consideration of the three main components of South African public university revenue, as well as the proportionate relationship between non-staff operating expenses and total expenses. The framework displays considerable levels of stability and consistency over the seven year review period, and its constructs are, in addition, robust to the application of multiple alternative confirmatory tests involving financial data that are independent of the factor solutions. The financial condition assessment framework developed in this thesis offers a contribution to a broader discourse in nonprofit finance and accounting, with a focus on public university finances.
- Full Text:
- Date Issued: 2016
- Authors: Bunting, Mark Bevan
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:923 , http://hdl.handle.net/10962/d1021298 , http://orcid.org/0000-0002-3392-554X
- Description: In this thesis, an analytical framework is developed for the assessment of the financial condition of South African public universities. Foundational constructs of nonprofit economics are applied in the consideration of financial theories of nonprofit organisations in general, and public universities in particular. From this review, a number of hypotheses are developed. Each of these specifies a positive or negative association between a university's financial condition and a particular dimension of its assets, liabilities, equity, revenues, expenses and surplus. From the nonprofit financial analysis literature, ratios and indicators relevant to these hypotheses are selected. Audited data from the annual financial statements of the universities for the seven year period 2007 to 2013 are substantially transformed in mitigation of failures in accounting, auditing and accountability. The adjusted accounting numbers are used to calculate the financial indicators applicable to each university. Exploratory factor analysis is implemented to categorise and organise this large indicator set on the basis of identified associations with a smaller number of factors. It is found that the financial condition of South African public universities is defined by two broad financial characteristics, capital and revenue. Assessment of the capital dimension is informed by a focus on institutional equity, with particular emphasis on expendable equity and its proportionate relationships with surplus, total capital, and total expenses. The revenue dimension is appropriately evaluated in the context of a comparative and interactive consideration of the three main components of South African public university revenue, as well as the proportionate relationship between non-staff operating expenses and total expenses. The framework displays considerable levels of stability and consistency over the seven year review period, and its constructs are, in addition, robust to the application of multiple alternative confirmatory tests involving financial data that are independent of the factor solutions. The financial condition assessment framework developed in this thesis offers a contribution to a broader discourse in nonprofit finance and accounting, with a focus on public university finances.
- Full Text:
- Date Issued: 2016
The influence of introduced forest management practices on transformative social learning in a selected social-ecological forest community : a case of PFM and REDD projects at Pugu and Kazimzumbwi Forest Reserves in Tanzania
- Authors: Ferdinand, Victoria Ugulumu
- Date: 2016
- Subjects: Forest management -- Tanzania , Forest reserves -- Tanzania , Transformative learning , Social ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2064 , http://hdl.handle.net/10962/d1020333
- Description: This research investigates the influence of introduced forest management approaches on transformative social learning in the community surrounding the Pugu and Kazimzumbwi forest reserves in Tanzania from 2000 to 2015. The term transformative social learning reflects an understanding of learning processes that emerge through conscious changes in the perspectives of individuals or communities while interacting with forest management practices. The investigation explores the learning (if any) that occurred in the community and how and why the learning occurred. It also explores whether the learning was social and transformative and examines the conditions that enable or constrain transformative social learning at the Pugu and Kazimzumbwi community. Thus, the three concepts of social learning, transformative learning, and social practices are central to the research. Participatory Forest Management (PFM) emerged globally in the early 1980s to mobilise rural capabilities and resources in development and environmental stewardship. The Pugu and Kazimzumbwi community was introduced to Participatory Forest Management (PFM) projects by the late 1990s. The recent global focus on empowering communities around forests has drawn attention towards transformational adaptation to climate change impacts and building resilience capacities. As a result, in 2011 the Pugu and Kazimzumbwi community started working with a project for Reduction of Emissions through Deforestation and forest Degradation (REDD), which forms a key focus in this study as the most recently introduced PFM with embedded social learning assumptions. This research is designed and conducted as a qualitative case study. The research seeks to study the complex object of socially and contextually constructed learning through a systemic exploration of learning,using semi-structured interviews, focus group discussions, analysis of documents and archival records as well as observations and a reflexive workshop. Supportive information throughfield notes and audio voice and video recording was also generated. A contextual profile of the research site was conducted in March 2012, prior to the actual data collection in 2013 and 2014. Field explorations during the contextual profile helped to describe the research site and promote initial understanding of the context. During data collection, field inquiries based on interactive relationships between a researcher and participants stimulated practice memories and people’s living experiences with forestry and the introduced PFM projects under examination. Analysis of data employed analytical modes of induction, abduction and retroduction. Thick descriptions of learning obtained from fieldi based interactionswere produced before re-contextualising data through theoretical lenses. The research employed realist social theory by Archer (1995), under-laboured by critical realism, and practice theory advanced by Schatzki (2012) and Kemmis et al. (2014). The research process as a whole was underlaboured by the layered ontology of critical realism which proposes emergence of phenomena in open systems as shaped by interacting mechanisms which in this study were both material / ecological and social /political /economic /cultural. And more...
- Full Text:
- Date Issued: 2016
- Authors: Ferdinand, Victoria Ugulumu
- Date: 2016
- Subjects: Forest management -- Tanzania , Forest reserves -- Tanzania , Transformative learning , Social ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2064 , http://hdl.handle.net/10962/d1020333
- Description: This research investigates the influence of introduced forest management approaches on transformative social learning in the community surrounding the Pugu and Kazimzumbwi forest reserves in Tanzania from 2000 to 2015. The term transformative social learning reflects an understanding of learning processes that emerge through conscious changes in the perspectives of individuals or communities while interacting with forest management practices. The investigation explores the learning (if any) that occurred in the community and how and why the learning occurred. It also explores whether the learning was social and transformative and examines the conditions that enable or constrain transformative social learning at the Pugu and Kazimzumbwi community. Thus, the three concepts of social learning, transformative learning, and social practices are central to the research. Participatory Forest Management (PFM) emerged globally in the early 1980s to mobilise rural capabilities and resources in development and environmental stewardship. The Pugu and Kazimzumbwi community was introduced to Participatory Forest Management (PFM) projects by the late 1990s. The recent global focus on empowering communities around forests has drawn attention towards transformational adaptation to climate change impacts and building resilience capacities. As a result, in 2011 the Pugu and Kazimzumbwi community started working with a project for Reduction of Emissions through Deforestation and forest Degradation (REDD), which forms a key focus in this study as the most recently introduced PFM with embedded social learning assumptions. This research is designed and conducted as a qualitative case study. The research seeks to study the complex object of socially and contextually constructed learning through a systemic exploration of learning,using semi-structured interviews, focus group discussions, analysis of documents and archival records as well as observations and a reflexive workshop. Supportive information throughfield notes and audio voice and video recording was also generated. A contextual profile of the research site was conducted in March 2012, prior to the actual data collection in 2013 and 2014. Field explorations during the contextual profile helped to describe the research site and promote initial understanding of the context. During data collection, field inquiries based on interactive relationships between a researcher and participants stimulated practice memories and people’s living experiences with forestry and the introduced PFM projects under examination. Analysis of data employed analytical modes of induction, abduction and retroduction. Thick descriptions of learning obtained from fieldi based interactionswere produced before re-contextualising data through theoretical lenses. The research employed realist social theory by Archer (1995), under-laboured by critical realism, and practice theory advanced by Schatzki (2012) and Kemmis et al. (2014). The research process as a whole was underlaboured by the layered ontology of critical realism which proposes emergence of phenomena in open systems as shaped by interacting mechanisms which in this study were both material / ecological and social /political /economic /cultural. And more...
- Full Text:
- Date Issued: 2016
The mediating processes within social learning: women’s food and water security practices in the rural Eastern Cape
- Authors: Rivers, Nina
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/888 , vital:20000
- Description: The focus of this study was to explore the implicit and explicit mediating processes within the social learning of women’s food and water security practices in the rural Eastern Cape, South Africa. The study was undertaken in response to a growing problem of learning resources being decontextualised and therefore being of little relevance or use to the everyday practices of the people they were developed for. The central thesis of this study is that if the mediating processes that shape practice and learning are understood then these practices and learning can be better supported. One of the main foci of this study therefore is the concept of mediation and the importance of understanding the implicit and explicit mediating processes that shape learning and practice within the context of rainwater harvesting and food gardening practices of rural women. The study interprets these as social learning processes after the work of Lev Vygotsky and post-Vygotskian learning and activity development research, which recognises that all learning is socially mediated. This study also attempts to show that ontological factors also shape social learning processes via structural mediations (which are often also socially structured over time in history). Working within the broad framework of change oriented social learning, education for sustainability and the southern African water and food nexus the study is focused around two central research questions: 1) What are the mediating processes evident in and surrounding the learning of rainwater harvesting in the context of women’s water and food security in rural communities? And 2) How can a question-based learning resource extend the learning practices in this context? Drawing on three sensitising concepts of dialectics, reflexivity and agency, the study worked with Cultural Historical Activity Theory (CHAT), underpinned by critical realism, to reveal how the learning of rainwater and food gardening practitioners is constrained and enabled by mediating processes. The theory of mediation provided a useful theoretical lens with which to examine data generated. A case study approach was used in two sites in the rural Eastern Cape. The first was Cata village in the Amathole district and the second was a peri-urban settlement called Glenconnor in the Cacadu district. Each case study is constituted within a networked activity system. The study also used a narrative inquiry approach in order to bring to life the case studies, activity systems and some of the dynamics of social learning within the study. The methodological tools of document analysis, observations, in-depth interviews and focus group discussions were used to explore the implicit and explicit mediating processes that shape research participants’ rainwater harvesting and food gardening practices and their learning. Inductive, abductive and retroductive modes of inference were used to analyse data in and across case studies. One of the first findings of this study is that learning is embedded in and emergent from context in that it is mediated by implicit and explicit processes within each context. This makes such learning social, in the sense of social used by Vygotsky. The second finding showed that implicit and explicit mediation processes are constantly interacting in a dialectical process whether people are conscious of this interplay or not. This is an important dynamic to understand when trying to bring about societal transformation through education. Understanding the interaction between the implicit and explicit alerts researchers to the sociocultural dynamics inherent within social learning processes and therefore informs how learning resources and educational and development programmes should be designed and implemented. This study contributes to new knowledge in the environmental education field and the water knowledge sector. It makes a theoretical and empirical contribution to the body of knowledge concerned with socially mediated learning and situated learning approaches. The study illustrates how learning is embedded in context and also how learning emerges in relation to context via interactions between implicit and explicit mediation processes, and considers what this means for learning and development in the rural nexus of water and food security practices. This study also contributes to the growing body of post-Vygotskian social learning research in southern Africa that is being developed in the context of cultural historical activity theory as it shows the dialectical relationship that exists between implicit and explicit forms of mediation as these are embedded in, emergent from, and are externally mediated into activity systems in rural community contexts. This study contributes to a second area of knowledge: the water sector. With a background in anthropology which sensitised the researcher to contextual factors and approaching the study through an educational lens, the data has been worked with to surface and present the nuanced mediating processes that shape the learning and knowledge around water issues. This way of working and this focus on the socio-cultural is relatively new in the water sector in South Africa and gains significance in the light of an emergent interest in more complex social studies in the water sector which has traditionally been dominated by natural sciences and engineering. The significance of this study for rural South African women’s lives is that by understanding and taking account of their history, context, struggles and experiences, their learning and practices can be better supported through more relevant learning resources and programmes.
- Full Text:
- Date Issued: 2016
- Authors: Rivers, Nina
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/888 , vital:20000
- Description: The focus of this study was to explore the implicit and explicit mediating processes within the social learning of women’s food and water security practices in the rural Eastern Cape, South Africa. The study was undertaken in response to a growing problem of learning resources being decontextualised and therefore being of little relevance or use to the everyday practices of the people they were developed for. The central thesis of this study is that if the mediating processes that shape practice and learning are understood then these practices and learning can be better supported. One of the main foci of this study therefore is the concept of mediation and the importance of understanding the implicit and explicit mediating processes that shape learning and practice within the context of rainwater harvesting and food gardening practices of rural women. The study interprets these as social learning processes after the work of Lev Vygotsky and post-Vygotskian learning and activity development research, which recognises that all learning is socially mediated. This study also attempts to show that ontological factors also shape social learning processes via structural mediations (which are often also socially structured over time in history). Working within the broad framework of change oriented social learning, education for sustainability and the southern African water and food nexus the study is focused around two central research questions: 1) What are the mediating processes evident in and surrounding the learning of rainwater harvesting in the context of women’s water and food security in rural communities? And 2) How can a question-based learning resource extend the learning practices in this context? Drawing on three sensitising concepts of dialectics, reflexivity and agency, the study worked with Cultural Historical Activity Theory (CHAT), underpinned by critical realism, to reveal how the learning of rainwater and food gardening practitioners is constrained and enabled by mediating processes. The theory of mediation provided a useful theoretical lens with which to examine data generated. A case study approach was used in two sites in the rural Eastern Cape. The first was Cata village in the Amathole district and the second was a peri-urban settlement called Glenconnor in the Cacadu district. Each case study is constituted within a networked activity system. The study also used a narrative inquiry approach in order to bring to life the case studies, activity systems and some of the dynamics of social learning within the study. The methodological tools of document analysis, observations, in-depth interviews and focus group discussions were used to explore the implicit and explicit mediating processes that shape research participants’ rainwater harvesting and food gardening practices and their learning. Inductive, abductive and retroductive modes of inference were used to analyse data in and across case studies. One of the first findings of this study is that learning is embedded in and emergent from context in that it is mediated by implicit and explicit processes within each context. This makes such learning social, in the sense of social used by Vygotsky. The second finding showed that implicit and explicit mediation processes are constantly interacting in a dialectical process whether people are conscious of this interplay or not. This is an important dynamic to understand when trying to bring about societal transformation through education. Understanding the interaction between the implicit and explicit alerts researchers to the sociocultural dynamics inherent within social learning processes and therefore informs how learning resources and educational and development programmes should be designed and implemented. This study contributes to new knowledge in the environmental education field and the water knowledge sector. It makes a theoretical and empirical contribution to the body of knowledge concerned with socially mediated learning and situated learning approaches. The study illustrates how learning is embedded in context and also how learning emerges in relation to context via interactions between implicit and explicit mediation processes, and considers what this means for learning and development in the rural nexus of water and food security practices. This study also contributes to the growing body of post-Vygotskian social learning research in southern Africa that is being developed in the context of cultural historical activity theory as it shows the dialectical relationship that exists between implicit and explicit forms of mediation as these are embedded in, emergent from, and are externally mediated into activity systems in rural community contexts. This study contributes to a second area of knowledge: the water sector. With a background in anthropology which sensitised the researcher to contextual factors and approaching the study through an educational lens, the data has been worked with to surface and present the nuanced mediating processes that shape the learning and knowledge around water issues. This way of working and this focus on the socio-cultural is relatively new in the water sector in South Africa and gains significance in the light of an emergent interest in more complex social studies in the water sector which has traditionally been dominated by natural sciences and engineering. The significance of this study for rural South African women’s lives is that by understanding and taking account of their history, context, struggles and experiences, their learning and practices can be better supported through more relevant learning resources and programmes.
- Full Text:
- Date Issued: 2016
The development of trilingual literacy in primary schools in Kenya
- Authors: Mose, Peter N
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/815 , vital:19993
- Description: The Kenyan language in education policy contemplates development of trilingual literacy skills in pupils by the end of standard three. The purpose of this study was to determine to what extent standard three pupils were literate in their mother tongue (Ekegusii), Kiswahili, and English. The study was undertaken in the context of; a language in education policy that provides for the use of mother tongues and Kiswahili (as languages of instruction) in rural and urban schools respectively up to the end of standard three, followed by a transition to an English medium from standard four; a general negative public attitude towards mother tongue instruction; and substantial empirical evidence in support of mother tongue instruction in basic education. Cummins’ Linguistic Interdependence and Linguistic Threshold Hypotheses guided the study. Adopting a mixed methods approach, the study used direct classroom observations, face-to-face interviews, document analyses, and reading tests to obtain data. Thematic, content, and statistical approaches were used in data analysis. It was found that various stakeholders understand key aspects of the language in education policy differently. Secondly, efforts in mother tongue instruction in schools are not motivated by theoretical and empirical foundations; development efforts are hence ineffective and inadequate leaving majority of learners with below average literacy skills in their mother tongue by the end of standard three. Thirdly, teachers do not implement the language in education policy as spelt out in the relevant documents; the three languages have therefore been allocated various classroom functions. Fourthly, the factors that motivate the disregard of the language policy include the language of examinations and textbooks, and transition to standard four in which English is the language of instruction. Lastly, reading scores indicate that majority of pupils transiting to standard four do not possess adequate reading skills to enable them read to learn in a mother tongue, Kiswahili, and English. This is observed across rural, peri-urban, and urban schools. The study recommends that: The ministry of education conducts workshops to re-educate the relevant stakeholders on the meaning and significance of the language in education policy and the significance of mother tongue instruction in second language, literacy, and skill development. This should be followed by a re-classification of primary schools on the basis of linguistic homogeneity, or otherwise, to ensure the intention of the policy is achieved. This could include empowering individual schools to determine language of instruction in lower primary based on language predominance. Secondly, the ministry should provide relevant resources for mother tongues and Kiswahili to develop them as effective languages of instruction as recommended by various past education commission reports. Additionally, a bilingual course in teacher training colleges to equip primary school teachers for bilingualism and biliteracy development should be introduced; one implication of this is teachers giving notes and tests in the languages spelt out in the policy. Thirdly, the ministry should intensify inspection of schools to assess implementation of the policy. Fourthly, future studies should assess mother tongue literacies as well, since they determine the extent and success of second language acquisition and learning; and measures should be put to ensure English is adequately resourced and taught well. Finally, mother tongue instruction should be extended up to, at least, standard five.
- Full Text:
- Date Issued: 2016
- Authors: Mose, Peter N
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/815 , vital:19993
- Description: The Kenyan language in education policy contemplates development of trilingual literacy skills in pupils by the end of standard three. The purpose of this study was to determine to what extent standard three pupils were literate in their mother tongue (Ekegusii), Kiswahili, and English. The study was undertaken in the context of; a language in education policy that provides for the use of mother tongues and Kiswahili (as languages of instruction) in rural and urban schools respectively up to the end of standard three, followed by a transition to an English medium from standard four; a general negative public attitude towards mother tongue instruction; and substantial empirical evidence in support of mother tongue instruction in basic education. Cummins’ Linguistic Interdependence and Linguistic Threshold Hypotheses guided the study. Adopting a mixed methods approach, the study used direct classroom observations, face-to-face interviews, document analyses, and reading tests to obtain data. Thematic, content, and statistical approaches were used in data analysis. It was found that various stakeholders understand key aspects of the language in education policy differently. Secondly, efforts in mother tongue instruction in schools are not motivated by theoretical and empirical foundations; development efforts are hence ineffective and inadequate leaving majority of learners with below average literacy skills in their mother tongue by the end of standard three. Thirdly, teachers do not implement the language in education policy as spelt out in the relevant documents; the three languages have therefore been allocated various classroom functions. Fourthly, the factors that motivate the disregard of the language policy include the language of examinations and textbooks, and transition to standard four in which English is the language of instruction. Lastly, reading scores indicate that majority of pupils transiting to standard four do not possess adequate reading skills to enable them read to learn in a mother tongue, Kiswahili, and English. This is observed across rural, peri-urban, and urban schools. The study recommends that: The ministry of education conducts workshops to re-educate the relevant stakeholders on the meaning and significance of the language in education policy and the significance of mother tongue instruction in second language, literacy, and skill development. This should be followed by a re-classification of primary schools on the basis of linguistic homogeneity, or otherwise, to ensure the intention of the policy is achieved. This could include empowering individual schools to determine language of instruction in lower primary based on language predominance. Secondly, the ministry should provide relevant resources for mother tongues and Kiswahili to develop them as effective languages of instruction as recommended by various past education commission reports. Additionally, a bilingual course in teacher training colleges to equip primary school teachers for bilingualism and biliteracy development should be introduced; one implication of this is teachers giving notes and tests in the languages spelt out in the policy. Thirdly, the ministry should intensify inspection of schools to assess implementation of the policy. Fourthly, future studies should assess mother tongue literacies as well, since they determine the extent and success of second language acquisition and learning; and measures should be put to ensure English is adequately resourced and taught well. Finally, mother tongue instruction should be extended up to, at least, standard five.
- Full Text:
- Date Issued: 2016