A critical ethnographic study of report writing as a literacy practice by automotive engineers
- Authors: Harran, Marcelle
- Date: 2007
- Subjects: English language -- Written English -- South Africa Written communication -- South Africa Literacy -- Social aspects -- South Africa Engineers -- Language -- South Africa Communication in engineering -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1476 , http://hdl.handle.net/10962/d1003357
- Description: This study describes the social practices involved in the situated activity of report writing in an engineering automotive discourse community in South Africa. In particular, the study focuses on the subjectivity of predominantly English Second Language (ESL) engineers writing reports by determining what literacy means to them and what meanings they give to dominant literacy practices in report writing, especially feedback in text production. In the South African engineering workplace, because of the diversity and complexity of language and identity issues, the appropriation of the required literacy skills tends to be multifaceted. This context is made more complex as English is the business language upon which engineering is based with engineering competence often related to English proficiency. Therefore, the study is located within the understanding that literacy is always situated within specific discoursal practices whose ideologies, beliefs, power relations, values and identities are manifested rhetorically. The basis for this critical theory of literacy is the assertion that literacy is a social practice which involves not only observable units of behaviour but values, attitudes, feelings and social relationships. As the institution’s socio-cultural context in the form of embedded historical and institutional forces impact on writer identity and writing practices or ways of doing report writing, notions of writing as a transparent and autonomous system are also challenged. As critical ethnography is concerned with multiple perspectives, it was selected as the preferred methodology and critical realism to derive definitions of truth and validity. Critical ethnography explores cultural orientations of local practice contexts and incorporates multiple understandings providing a holistic understanding of the complexity of writing practices. As human experience can only be known under particular descriptions, usually in terms of available discourses such as language, writing and rhetoric, the dominant practices emerging in response to the report acceptance event are explored, especially that of supervisor feedback practices as they causally impact on report-writing practices during the practice of report acceptance. Although critical realism does not necessarily demonstrate successful causal explanations, it does look for substantial relations within wider contexts to illuminate part-whole relationships. Therefore, an attempt is made to find representativeness or fit with situated engineering literacy practices and wider and changing literacy contexts, especially the impact of Higher Education and world Englishes as well as the expanding influence of technological and digital systems on report-writing practices.
- Full Text:
- Date Issued: 2007
- Authors: Harran, Marcelle
- Date: 2007
- Subjects: English language -- Written English -- South Africa Written communication -- South Africa Literacy -- Social aspects -- South Africa Engineers -- Language -- South Africa Communication in engineering -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1476 , http://hdl.handle.net/10962/d1003357
- Description: This study describes the social practices involved in the situated activity of report writing in an engineering automotive discourse community in South Africa. In particular, the study focuses on the subjectivity of predominantly English Second Language (ESL) engineers writing reports by determining what literacy means to them and what meanings they give to dominant literacy practices in report writing, especially feedback in text production. In the South African engineering workplace, because of the diversity and complexity of language and identity issues, the appropriation of the required literacy skills tends to be multifaceted. This context is made more complex as English is the business language upon which engineering is based with engineering competence often related to English proficiency. Therefore, the study is located within the understanding that literacy is always situated within specific discoursal practices whose ideologies, beliefs, power relations, values and identities are manifested rhetorically. The basis for this critical theory of literacy is the assertion that literacy is a social practice which involves not only observable units of behaviour but values, attitudes, feelings and social relationships. As the institution’s socio-cultural context in the form of embedded historical and institutional forces impact on writer identity and writing practices or ways of doing report writing, notions of writing as a transparent and autonomous system are also challenged. As critical ethnography is concerned with multiple perspectives, it was selected as the preferred methodology and critical realism to derive definitions of truth and validity. Critical ethnography explores cultural orientations of local practice contexts and incorporates multiple understandings providing a holistic understanding of the complexity of writing practices. As human experience can only be known under particular descriptions, usually in terms of available discourses such as language, writing and rhetoric, the dominant practices emerging in response to the report acceptance event are explored, especially that of supervisor feedback practices as they causally impact on report-writing practices during the practice of report acceptance. Although critical realism does not necessarily demonstrate successful causal explanations, it does look for substantial relations within wider contexts to illuminate part-whole relationships. Therefore, an attempt is made to find representativeness or fit with situated engineering literacy practices and wider and changing literacy contexts, especially the impact of Higher Education and world Englishes as well as the expanding influence of technological and digital systems on report-writing practices.
- Full Text:
- Date Issued: 2007
A model for a context aware machine-based personal memory manager and its implementation using a visual programming environment
- Authors: Tsegaye, Melekam Asrat
- Date: 2007
- Subjects: Visual programming (Computer science) Memory management (Computer science) Memory -- Data processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4640 , http://hdl.handle.net/10962/d1006563
- Description: Memory is a part of cognition. It is essential for an individual to function normally in society. It encompasses an individual's lifetime experience, thus defining his identity. This thesis develops the concept of a machine-based personal memory manager which captures and manages an individual's day-to-day external memories. Rather than accumulating large amounts of data which has to be mined for useful memories, the machine-based memory manager automatically organizes memories as they are captured to enable their quick retrieval and use. The main functions of the machine-based memory manager envisioned in this thesis are the support and the augmentation of an individual's biological memory system. In the thesis, a model for a machine-based memory manager is developed. A visual programming environment, which can be used to build context aware applications as well as a proof-of-concept machine-based memory manager, is conceptualized and implemented. An experimental machine-based memory manager is implemented and evaluated. The model describes a machine-based memory manager which manages an individual's external memories by context. It addresses the management of external memories which accumulate over long periods of time by proposing a context aware file system which automatically organizes external memories by context. It describes how personal memory management can be facilitated by machine using six entities (life streams, memory producers, memory consumers, a memory manager, memory fragments and context descriptors) and the processes in which these entities participate (memory capture, memory encoding and decoding, memory decoding and retrieval). The visual programming environment represents a development tool which contains facilities that support context aware application programming. For example, it provides facilities which enable the definition and use of virtual sensors. It enables rapid programming with a focus on component re-use and dynamic composition of applications through a visual interface. The experimental machine-based memory manager serves as an example implementation of the machine-based memory manager which is described by the model developed in this thesis. The hardware used in its implementation consists of widely available components such as a camera, microphone and sub-notebook computer which are assembled in the form of a wearable computer. The software is constructed using the visual programming environment developed in this thesis. It contains multiple sensor drivers, context interpreters, a context aware file system as well as memory retrieval and presentation interfaces. The evaluation of the machine-based memory manager shows that it is possible to create a machine which monitors the states of an individual and his environment, and manages his external memories, thus supporting and augmenting his biological memory.
- Full Text:
- Date Issued: 2007
- Authors: Tsegaye, Melekam Asrat
- Date: 2007
- Subjects: Visual programming (Computer science) Memory management (Computer science) Memory -- Data processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4640 , http://hdl.handle.net/10962/d1006563
- Description: Memory is a part of cognition. It is essential for an individual to function normally in society. It encompasses an individual's lifetime experience, thus defining his identity. This thesis develops the concept of a machine-based personal memory manager which captures and manages an individual's day-to-day external memories. Rather than accumulating large amounts of data which has to be mined for useful memories, the machine-based memory manager automatically organizes memories as they are captured to enable their quick retrieval and use. The main functions of the machine-based memory manager envisioned in this thesis are the support and the augmentation of an individual's biological memory system. In the thesis, a model for a machine-based memory manager is developed. A visual programming environment, which can be used to build context aware applications as well as a proof-of-concept machine-based memory manager, is conceptualized and implemented. An experimental machine-based memory manager is implemented and evaluated. The model describes a machine-based memory manager which manages an individual's external memories by context. It addresses the management of external memories which accumulate over long periods of time by proposing a context aware file system which automatically organizes external memories by context. It describes how personal memory management can be facilitated by machine using six entities (life streams, memory producers, memory consumers, a memory manager, memory fragments and context descriptors) and the processes in which these entities participate (memory capture, memory encoding and decoding, memory decoding and retrieval). The visual programming environment represents a development tool which contains facilities that support context aware application programming. For example, it provides facilities which enable the definition and use of virtual sensors. It enables rapid programming with a focus on component re-use and dynamic composition of applications through a visual interface. The experimental machine-based memory manager serves as an example implementation of the machine-based memory manager which is described by the model developed in this thesis. The hardware used in its implementation consists of widely available components such as a camera, microphone and sub-notebook computer which are assembled in the form of a wearable computer. The software is constructed using the visual programming environment developed in this thesis. It contains multiple sensor drivers, context interpreters, a context aware file system as well as memory retrieval and presentation interfaces. The evaluation of the machine-based memory manager shows that it is possible to create a machine which monitors the states of an individual and his environment, and manages his external memories, thus supporting and augmenting his biological memory.
- Full Text:
- Date Issued: 2007
A preliminary examination of selected biological links between four Eastern Cape estuaries and the inshore marine environment
- Authors: Vorwerk, Paul D
- Date: 2007
- Subjects: Estuaries -- South Africa -- Eastern Cape Marine fishes -- South Africa -- Eastern Cape Marine ecology -- South Africa -- Eastern Cape Estuarine ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5747 , http://hdl.handle.net/10962/d1005434
- Description: The coastal transition zone (CTZ), which links the terrestrial and marine environments, has been identified as a region of high biological diversity and elevated production. Results of studies conducted in the northern hemisphere indicate that the links between estuaries and the adjacent marine environment is critical to ecological functioning within the CTZ. This study assessed the influence of selected estuaries with different hydrodynamic characteristics on the adjacent marine environment along the south-eastern coastline of southern Africa. Four estuaries were examined, including two permanently open systems, the fresh water deprived Kariega and fresh water dominated Great Fish, and two temporarily open/closed estuaries (TOCE), the Kasouga and East Kleinemonde. Results of the study indicated that outflow of estuarine water from the Great Fish Estuary contributed to a plume of less saline water being evident within the adjacent marine environment. The plume of water was associated with increased zooplankton biomass and particulate organic matter (POM) and chlorophyll-a concentrations. Adjacent to the Kariega Estuary, no evidence of fresh water outflow into the marine environment was observed. However, in the sea directly opposite the mouth of the estuary an increase in zooplankton abundance and biomass was evident. Results of numerical analyses indicated that the increase in zooplankton abundance observed adjacent to the mouth of both permanently open estuaries could not be attributed to the export of zooplankton from the estuary, but rather the accumulation of marine species within the region. The mechanisms responsible for this accumulation were not determined, but it was thought to be associated with increased food availability in the estuarine frontal zone. A similar, but less dramatic biological response was also observed in the marine environment adjacent to the two TOCEs. It is suggested that the increase in biological activity within these regions could be ascribed to seepage of estuarine or ground water through the sand bar that separates these estuaries from the sea. Results of stable carbon isotope analyses indicated that both the Great Fish and Kariega estuaries exported carbon to the nearshore marine environment. The area influenced by estuarine derived carbon was dependent on the volume of estuarine outflow to the marine environment. Adjacent to the fresh water dominated Great Fish Estuary, estuarine derived carbon was recorded up to 12km from the mouth, while adjacent to the fresh water deprived Kariega, estuarine derived carbon was only evident directly opposite the mouth. The recruitment of macrozooplankton (> 2cm) into the fresh water deprived Kariega Estuary was in the range recorded for other permanently open southern African estuaries with higher fresh water flow rates. This indicates that the mechanisms which allow estuarine dependent larvae to locate and enter estuaries are not related to fresh water inflow. In conclusion, this study has demonstrated that despite their small size relative to European and North American systems, South African permanently open and temporarily open/closed estuaries also influence biological activity within the adjacent nearshore marine environment.
- Full Text:
- Date Issued: 2007
- Authors: Vorwerk, Paul D
- Date: 2007
- Subjects: Estuaries -- South Africa -- Eastern Cape Marine fishes -- South Africa -- Eastern Cape Marine ecology -- South Africa -- Eastern Cape Estuarine ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5747 , http://hdl.handle.net/10962/d1005434
- Description: The coastal transition zone (CTZ), which links the terrestrial and marine environments, has been identified as a region of high biological diversity and elevated production. Results of studies conducted in the northern hemisphere indicate that the links between estuaries and the adjacent marine environment is critical to ecological functioning within the CTZ. This study assessed the influence of selected estuaries with different hydrodynamic characteristics on the adjacent marine environment along the south-eastern coastline of southern Africa. Four estuaries were examined, including two permanently open systems, the fresh water deprived Kariega and fresh water dominated Great Fish, and two temporarily open/closed estuaries (TOCE), the Kasouga and East Kleinemonde. Results of the study indicated that outflow of estuarine water from the Great Fish Estuary contributed to a plume of less saline water being evident within the adjacent marine environment. The plume of water was associated with increased zooplankton biomass and particulate organic matter (POM) and chlorophyll-a concentrations. Adjacent to the Kariega Estuary, no evidence of fresh water outflow into the marine environment was observed. However, in the sea directly opposite the mouth of the estuary an increase in zooplankton abundance and biomass was evident. Results of numerical analyses indicated that the increase in zooplankton abundance observed adjacent to the mouth of both permanently open estuaries could not be attributed to the export of zooplankton from the estuary, but rather the accumulation of marine species within the region. The mechanisms responsible for this accumulation were not determined, but it was thought to be associated with increased food availability in the estuarine frontal zone. A similar, but less dramatic biological response was also observed in the marine environment adjacent to the two TOCEs. It is suggested that the increase in biological activity within these regions could be ascribed to seepage of estuarine or ground water through the sand bar that separates these estuaries from the sea. Results of stable carbon isotope analyses indicated that both the Great Fish and Kariega estuaries exported carbon to the nearshore marine environment. The area influenced by estuarine derived carbon was dependent on the volume of estuarine outflow to the marine environment. Adjacent to the fresh water dominated Great Fish Estuary, estuarine derived carbon was recorded up to 12km from the mouth, while adjacent to the fresh water deprived Kariega, estuarine derived carbon was only evident directly opposite the mouth. The recruitment of macrozooplankton (> 2cm) into the fresh water deprived Kariega Estuary was in the range recorded for other permanently open southern African estuaries with higher fresh water flow rates. This indicates that the mechanisms which allow estuarine dependent larvae to locate and enter estuaries are not related to fresh water inflow. In conclusion, this study has demonstrated that despite their small size relative to European and North American systems, South African permanently open and temporarily open/closed estuaries also influence biological activity within the adjacent nearshore marine environment.
- Full Text:
- Date Issued: 2007
A social realist account of the emergence of a formal academic staff development programme at a South African university
- Authors: Quinn, Lynn
- Date: 2007
- Subjects: Teachers -- Training of -- South Africa Education, Higher -- South Africa Graduate students -- South Africa Universities and colleges -- South Africa -- Graduate work
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1321 , http://hdl.handle.net/10962/d1003954
- Description: Using social realist theory and particularly the morphogenetic/morphostatic methodology advocated by Margaret Archer, this study offers a critical examination of the emergence of a formal academic staff development programme at a small South African university (SSAU). Archer’s morphogenetic approach enabled an investigation of the interface between culture, structure and agency (at macro, mezo and micro levels) in order to theorize about the material, ideational and agential conditions that obtained and which in turn enabled the emergence of the Postgraduate Diploma of Higher Education (PGDHE) at the SSAU. The study therefore advances concrete propositions about the cultural, structural and agential conditions for transformation which existed at a particular time in the history of higher education (and the subfield of educational development) which enabled the introduction of the PGDHE. Analysis of the data suggests that what occurred at SSAU was a disruption of the morphostatic synchrony between structure and culture brought about by new discourses and structures emanating from the broader international and national higher education context. In particular, it seems that attempts at reconciling the constraining contradictions between the discourses and structures related to quality assurance on the one hand and educational development on the other resulted in a conjunction between transformation at the levels of both the cultural system and social structure. This conjunction, along with the actions of key Institutional agents and the morphogenesis of the staff of the Educational Development Unit, created sufficiently enabling conditions in the Institution for the introduction of the PGDHE. The research adds to knowledge through insights into the contribution that the ideas, beliefs, values, ideologies and theories about higher education broadly and about educational development specifically make to enabling or constraining conditions for the professionalization of academic staff in higher education institutions. It uncovers how relevant structures at the international, national and institutional levels can shape the practice of educational development and specifically staff development. It has generated insights into how the relevant people and the positions they hold can impact on staff development practices. In summary, the research could contribute towards emancipatory knowledge which could be used by SSAU and educational development practitioners elsewhere to inform future planning and decision making in relation to educational development and more specifically staff development practices in their contexts.
- Full Text:
- Date Issued: 2007
- Authors: Quinn, Lynn
- Date: 2007
- Subjects: Teachers -- Training of -- South Africa Education, Higher -- South Africa Graduate students -- South Africa Universities and colleges -- South Africa -- Graduate work
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1321 , http://hdl.handle.net/10962/d1003954
- Description: Using social realist theory and particularly the morphogenetic/morphostatic methodology advocated by Margaret Archer, this study offers a critical examination of the emergence of a formal academic staff development programme at a small South African university (SSAU). Archer’s morphogenetic approach enabled an investigation of the interface between culture, structure and agency (at macro, mezo and micro levels) in order to theorize about the material, ideational and agential conditions that obtained and which in turn enabled the emergence of the Postgraduate Diploma of Higher Education (PGDHE) at the SSAU. The study therefore advances concrete propositions about the cultural, structural and agential conditions for transformation which existed at a particular time in the history of higher education (and the subfield of educational development) which enabled the introduction of the PGDHE. Analysis of the data suggests that what occurred at SSAU was a disruption of the morphostatic synchrony between structure and culture brought about by new discourses and structures emanating from the broader international and national higher education context. In particular, it seems that attempts at reconciling the constraining contradictions between the discourses and structures related to quality assurance on the one hand and educational development on the other resulted in a conjunction between transformation at the levels of both the cultural system and social structure. This conjunction, along with the actions of key Institutional agents and the morphogenesis of the staff of the Educational Development Unit, created sufficiently enabling conditions in the Institution for the introduction of the PGDHE. The research adds to knowledge through insights into the contribution that the ideas, beliefs, values, ideologies and theories about higher education broadly and about educational development specifically make to enabling or constraining conditions for the professionalization of academic staff in higher education institutions. It uncovers how relevant structures at the international, national and institutional levels can shape the practice of educational development and specifically staff development. It has generated insights into how the relevant people and the positions they hold can impact on staff development practices. In summary, the research could contribute towards emancipatory knowledge which could be used by SSAU and educational development practitioners elsewhere to inform future planning and decision making in relation to educational development and more specifically staff development practices in their contexts.
- Full Text:
- Date Issued: 2007
A sociological analysis of intermediary non-governmental organizations and land reform in contemporary Zimbabwe
- Authors: Helliker, Kirk David
- Date: 2007
- Subjects: Non-governmental organizations -- Zimbabwe Land reform -- Zimbabwe Land use -- Zimbabwe Sociology -- Philosophy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3303 , http://hdl.handle.net/10962/d1003091
- Description: The thesis offers an original sociological understanding of intermediary Non-Governmental Organizations (NGOs) in the modern world. This is pursued through a study of NGOs and land reform in contemporary Zimbabwe. The prevailing literature on NGOs is marked by a sociological behaviourism that analyses NGOs in terms of external relations and the object-subject dualism. This behaviourism has both ‘structuralist’ and ‘empiricist’ trends that lead to instrumentalist and functionalist forms of argumentation. The thesis details an alternative conceptual corpus that draws upon the epistemological and theoretical insights of Marx and Weber. The epistemological reasoning of Marx involves processes of deconstruction and reconstruction. This entails conceptualizing NGOs as social forms that embody contradictory relations and, for analytical purposes, the thesis privileges the contradiction between ‘the global’ and ‘the local’. In this regard, it speaks about processes of ‘glocalization’ and ‘glocal modernities’ in which NGOs become immersed. The social field of NGOs is marked by ambiguities and tensions, and NGOs seek to ‘negotiate’ and manoeuvre their way through this field by a variety of organizational practices. Understanding these practices necessitates studying NGOs ‘from within’ and drawing specifically on Weber’s notion of ‘meaning’. These practices often entail activities that stabilize and simplify the world and work of NGOs, and this involves NGOs in prioritizing their own organizational sustainability. In handling the tension between ‘the global’ and ‘the local’, NGOs also tend to privilege global trajectories over local initiatives. The thesis illustrates these points in relation to the work of intermediary NGOs in Zimbabwe over the past ten years. Since the year 2000, a radical restructuring of agrarian relations has occurred, and this has been based upon the massive redistribution of land. In this respect, local empowering initiatives have dramatically asserted themselves against globalizing trajectories. These changes have posed serious challenges to ‘land’ NGOs, that is, NGOs involved in land reform either as advocates for reform or as rural development NGOs. The thesis shows how a range of diverse ‘land’ NGOs has ‘handled’ the heightened contradictions in their social field in ways that maintain their organizational coherence and integrity.
- Full Text:
- Date Issued: 2007
- Authors: Helliker, Kirk David
- Date: 2007
- Subjects: Non-governmental organizations -- Zimbabwe Land reform -- Zimbabwe Land use -- Zimbabwe Sociology -- Philosophy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3303 , http://hdl.handle.net/10962/d1003091
- Description: The thesis offers an original sociological understanding of intermediary Non-Governmental Organizations (NGOs) in the modern world. This is pursued through a study of NGOs and land reform in contemporary Zimbabwe. The prevailing literature on NGOs is marked by a sociological behaviourism that analyses NGOs in terms of external relations and the object-subject dualism. This behaviourism has both ‘structuralist’ and ‘empiricist’ trends that lead to instrumentalist and functionalist forms of argumentation. The thesis details an alternative conceptual corpus that draws upon the epistemological and theoretical insights of Marx and Weber. The epistemological reasoning of Marx involves processes of deconstruction and reconstruction. This entails conceptualizing NGOs as social forms that embody contradictory relations and, for analytical purposes, the thesis privileges the contradiction between ‘the global’ and ‘the local’. In this regard, it speaks about processes of ‘glocalization’ and ‘glocal modernities’ in which NGOs become immersed. The social field of NGOs is marked by ambiguities and tensions, and NGOs seek to ‘negotiate’ and manoeuvre their way through this field by a variety of organizational practices. Understanding these practices necessitates studying NGOs ‘from within’ and drawing specifically on Weber’s notion of ‘meaning’. These practices often entail activities that stabilize and simplify the world and work of NGOs, and this involves NGOs in prioritizing their own organizational sustainability. In handling the tension between ‘the global’ and ‘the local’, NGOs also tend to privilege global trajectories over local initiatives. The thesis illustrates these points in relation to the work of intermediary NGOs in Zimbabwe over the past ten years. Since the year 2000, a radical restructuring of agrarian relations has occurred, and this has been based upon the massive redistribution of land. In this respect, local empowering initiatives have dramatically asserted themselves against globalizing trajectories. These changes have posed serious challenges to ‘land’ NGOs, that is, NGOs involved in land reform either as advocates for reform or as rural development NGOs. The thesis shows how a range of diverse ‘land’ NGOs has ‘handled’ the heightened contradictions in their social field in ways that maintain their organizational coherence and integrity.
- Full Text:
- Date Issued: 2007
A study of the summarizing strategies used by ESL first year science students at the University of Botswana
- Authors: Chimbganda, Ambrose Bruce
- Date: 2007
- Subjects: English language -- Study and teaching (Foreign speakers) -- Botswana English language -- Study and teaching (Higher) -- Botswana Science -- Study and teaching (Higher) -- Botswana Language and education -- Botswana College students -- Botswana -- Language
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2341 , http://hdl.handle.net/10962/d1002623
- Description: One of the major problems faced by speakers of English as a second language (ESL) or non-native speakers of English (NNS) is that when they go to college or university, they find themselves without sufficient academic literacy skills to enable them to navigate their learning successfully, such as the ability to summarize textual material. This thesis examines the summarizing strategies used by ESL first year science students at the University of Botswana. Using multiple data collection methods, otherwise known as triangulation or pluralistic research, which is a combination of quantitative and qualitative methods, one hundred and twenty randomly sampled students completed questionnaires and summarized a scientific text. In order to observe the students more closely, nine students (3 high-, 3 average- and 3 low-proficiency) were purposively selected from the sample and wrote a further summary. The nine students were later interviewed in order to find out from them the kinds of strategies they had used in summarizing the texts. To obtain systematic data, the summaries and the taped interview were coded and analyzed using a hybrid scoring classification previously used by other researchers. The results from the Likert type of questionnaire suggest that the ESL first year science students are 'aware' of the appropriate reading, production and self-assessment strategies to use when summarizing. However, when the data from the questionnaire were cross-checked against the strategies they had used in the actual summarization of the text, most of their claims, especially those of the low-proficiency students, were not sustained. As a whole, the results show that high-proficiency students produce more accurate idea units and are more capable of generalizing ideas than low-proficiency students who prefer to "cut and paste" ideas. There are also significant differences between high- and low proficiency students in the manner in which they decode the text: low-proficiency students produce more distortions in their summaries than high-proficiency students who generally give accurate information. Similarly, high-proficiency students are able to sort out global ideas from a labyrinth of localized ideas, unlike average- and low-proficiency students who include trivial information. The same trend is observed with paraphrasing and sentence combinations: high-proficiency students are generally able to recast and coordinate their ideas, unlike low-proficiency students who produce run-on ideas. In terms of the discrete cognitive and meta-cognitive skills preferred by students, low proficiency students are noticeably unable to exploit pre-summarizing cognitive strategies such as discriminating, selecting, note-making, grouping, inferring meanings of new words and using synonyms to convey the intended meanings. There are also greater differences between high- and low-proficiency students when it comes to the use of meta-cognitive strategies. Unlike high-proficiency students who use their reservoir of meta-cognitive skills such as self-judgment, low-proficiency students ostensibly find it difficult to direct their summaries to the demands of the task and are unable to check the accuracy of their summaries. The findings also show that some of the high-proficiency students and many average- and low-proficiency students distort idea units, find it difficult to use their own words and cannot distinguish between main and supporting details. This resulted in the production of circuitous summaries that often failed to capture the gist of the argument. The way the students processed the main ideas also reveals an inherent weakness: most students of different proficiency levels were unable to combine ideas from different paragraphs to produce a coherent text. Not surprising, then, there were too many long summaries produced by both high- and low-proficiency students. To tackle some of the problems related to summarization, pre-reading strategies can be taught, which activate relevant prior knowledge, so that the learning of new knowledge can be facilitated. During the reading process students can become more meta-cognitively aware by monitoring their level of understanding of the text by using, for example, the strategy suggested by Schraw (1998) of "stop, read and think". Text analysis can also be used to help the students identify the main themes or macro-propositions in a text, and hence gain a more global perspective of the content, which is important for selecting the main ideas in a text. A particularly useful approach to fostering a deeper understanding of content is to use a form of reciprocal or peer-mediated teaching, in which students in pairs can articulate to each other their understanding of the main ideas expressed in the text. As part of the solution to the problems faced by students when processing information, we need to take Sewlall's (2000: 170) advice that there should be "a paradigm shift in the learning philosophy from content-based to an emphasis on the acquisition of skills". In this regard, both content and ESL teachers need to train their students in the explicit use of summarizing strategies, and to plan interwoven lessons and learning activities that develop the learners' intellectual ways of dealing with different learning problems so that they can make learning quicker, easier, more effective and exciting.
- Full Text:
- Date Issued: 2007
- Authors: Chimbganda, Ambrose Bruce
- Date: 2007
- Subjects: English language -- Study and teaching (Foreign speakers) -- Botswana English language -- Study and teaching (Higher) -- Botswana Science -- Study and teaching (Higher) -- Botswana Language and education -- Botswana College students -- Botswana -- Language
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2341 , http://hdl.handle.net/10962/d1002623
- Description: One of the major problems faced by speakers of English as a second language (ESL) or non-native speakers of English (NNS) is that when they go to college or university, they find themselves without sufficient academic literacy skills to enable them to navigate their learning successfully, such as the ability to summarize textual material. This thesis examines the summarizing strategies used by ESL first year science students at the University of Botswana. Using multiple data collection methods, otherwise known as triangulation or pluralistic research, which is a combination of quantitative and qualitative methods, one hundred and twenty randomly sampled students completed questionnaires and summarized a scientific text. In order to observe the students more closely, nine students (3 high-, 3 average- and 3 low-proficiency) were purposively selected from the sample and wrote a further summary. The nine students were later interviewed in order to find out from them the kinds of strategies they had used in summarizing the texts. To obtain systematic data, the summaries and the taped interview were coded and analyzed using a hybrid scoring classification previously used by other researchers. The results from the Likert type of questionnaire suggest that the ESL first year science students are 'aware' of the appropriate reading, production and self-assessment strategies to use when summarizing. However, when the data from the questionnaire were cross-checked against the strategies they had used in the actual summarization of the text, most of their claims, especially those of the low-proficiency students, were not sustained. As a whole, the results show that high-proficiency students produce more accurate idea units and are more capable of generalizing ideas than low-proficiency students who prefer to "cut and paste" ideas. There are also significant differences between high- and low proficiency students in the manner in which they decode the text: low-proficiency students produce more distortions in their summaries than high-proficiency students who generally give accurate information. Similarly, high-proficiency students are able to sort out global ideas from a labyrinth of localized ideas, unlike average- and low-proficiency students who include trivial information. The same trend is observed with paraphrasing and sentence combinations: high-proficiency students are generally able to recast and coordinate their ideas, unlike low-proficiency students who produce run-on ideas. In terms of the discrete cognitive and meta-cognitive skills preferred by students, low proficiency students are noticeably unable to exploit pre-summarizing cognitive strategies such as discriminating, selecting, note-making, grouping, inferring meanings of new words and using synonyms to convey the intended meanings. There are also greater differences between high- and low-proficiency students when it comes to the use of meta-cognitive strategies. Unlike high-proficiency students who use their reservoir of meta-cognitive skills such as self-judgment, low-proficiency students ostensibly find it difficult to direct their summaries to the demands of the task and are unable to check the accuracy of their summaries. The findings also show that some of the high-proficiency students and many average- and low-proficiency students distort idea units, find it difficult to use their own words and cannot distinguish between main and supporting details. This resulted in the production of circuitous summaries that often failed to capture the gist of the argument. The way the students processed the main ideas also reveals an inherent weakness: most students of different proficiency levels were unable to combine ideas from different paragraphs to produce a coherent text. Not surprising, then, there were too many long summaries produced by both high- and low-proficiency students. To tackle some of the problems related to summarization, pre-reading strategies can be taught, which activate relevant prior knowledge, so that the learning of new knowledge can be facilitated. During the reading process students can become more meta-cognitively aware by monitoring their level of understanding of the text by using, for example, the strategy suggested by Schraw (1998) of "stop, read and think". Text analysis can also be used to help the students identify the main themes or macro-propositions in a text, and hence gain a more global perspective of the content, which is important for selecting the main ideas in a text. A particularly useful approach to fostering a deeper understanding of content is to use a form of reciprocal or peer-mediated teaching, in which students in pairs can articulate to each other their understanding of the main ideas expressed in the text. As part of the solution to the problems faced by students when processing information, we need to take Sewlall's (2000: 170) advice that there should be "a paradigm shift in the learning philosophy from content-based to an emphasis on the acquisition of skills". In this regard, both content and ESL teachers need to train their students in the explicit use of summarizing strategies, and to plan interwoven lessons and learning activities that develop the learners' intellectual ways of dealing with different learning problems so that they can make learning quicker, easier, more effective and exciting.
- Full Text:
- Date Issued: 2007
A taxonomic revision of the southern African endemic genus Gazania (Asteraceae) based on morphometric, genetic and phylogeographic data
- Authors: Howis, Seranne
- Date: 2007
- Subjects: Compositae Plant genetics DNA Endemic plants -- South Africa Plant ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4200 , http://hdl.handle.net/10962/d1003769
- Description: Gazania is a small genus of the subtribe Gorteriinae, tribe Arctoteae, that is endemic to southern Africa. The genus was last revised in 1959 by Roessler, who noted that delimitation of the species of Gazania can be “extraordinarily difficult”. Morphometric data was collected to test the reality of the 16 species as delimited by Roessler, who based species boundaries on morphological characters. Only six taxa were found to be morphologically distinct, while the remaining samples showed no species cohesion. DNA sequence data from two nuclear spacer regions (ITS and ETS) and four chloroplast noncoding regions (the trnL and rpS16 introns, and the psbA-trnH and trnL-F spacers) of 43 samples were utilised to create a species level phylogeny and to investigate correlations between genetically delimited units and morphologically defined taxa. DNA sequence data reveal that seven species (as delimited by Roessler) are morphologically and genetically distinct. The remaining nine of Roessler’s species fall into a morphologically and genetically overlapping continuum that forms an ochlospecies. Phylogeographic methods (based on an expanded ITS and ETS DNA sequence data set from 169 samples) were employed to further resolve the limits of species, with special focus on the clades within the ochlospecies. These genetically defined clades were correlated with their geographical distributions, and in combination with molecular dating techniques, used to elucidate the recent climatic or environmental factors that may have shaped the phylogeographic structure of the genus. Phylogeographic patterns and molecular dating reveals that the genus Gazania is an example of a South African endemic clade that has undergone episodic cladogenesis in response to fluctuating climatic conditions over the last seven million years. The ochlospecies within Gazania is a result of repeated cycles of climate driven isolation in refugia and subsequent expansion and hybridization events during the Pliocene and Pleistocene. Comparisons with phylogeographic studies on other organisms reveal a common pattern indicative of the presence and evolutionary importance of an ancestral refugium in the arid Richtersveld / Namib region of southern Africa.
- Full Text:
- Date Issued: 2007
- Authors: Howis, Seranne
- Date: 2007
- Subjects: Compositae Plant genetics DNA Endemic plants -- South Africa Plant ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4200 , http://hdl.handle.net/10962/d1003769
- Description: Gazania is a small genus of the subtribe Gorteriinae, tribe Arctoteae, that is endemic to southern Africa. The genus was last revised in 1959 by Roessler, who noted that delimitation of the species of Gazania can be “extraordinarily difficult”. Morphometric data was collected to test the reality of the 16 species as delimited by Roessler, who based species boundaries on morphological characters. Only six taxa were found to be morphologically distinct, while the remaining samples showed no species cohesion. DNA sequence data from two nuclear spacer regions (ITS and ETS) and four chloroplast noncoding regions (the trnL and rpS16 introns, and the psbA-trnH and trnL-F spacers) of 43 samples were utilised to create a species level phylogeny and to investigate correlations between genetically delimited units and morphologically defined taxa. DNA sequence data reveal that seven species (as delimited by Roessler) are morphologically and genetically distinct. The remaining nine of Roessler’s species fall into a morphologically and genetically overlapping continuum that forms an ochlospecies. Phylogeographic methods (based on an expanded ITS and ETS DNA sequence data set from 169 samples) were employed to further resolve the limits of species, with special focus on the clades within the ochlospecies. These genetically defined clades were correlated with their geographical distributions, and in combination with molecular dating techniques, used to elucidate the recent climatic or environmental factors that may have shaped the phylogeographic structure of the genus. Phylogeographic patterns and molecular dating reveals that the genus Gazania is an example of a South African endemic clade that has undergone episodic cladogenesis in response to fluctuating climatic conditions over the last seven million years. The ochlospecies within Gazania is a result of repeated cycles of climate driven isolation in refugia and subsequent expansion and hybridization events during the Pliocene and Pleistocene. Comparisons with phylogeographic studies on other organisms reveal a common pattern indicative of the presence and evolutionary importance of an ancestral refugium in the arid Richtersveld / Namib region of southern Africa.
- Full Text:
- Date Issued: 2007
A transdisciplinary explanatory critique of environmental education
- Authors: Price, Leigh
- Date: 2007
- Subjects: Environmental education Business enterprises -- Environmental aspects Corporations -- Environmental aspects Social responsibility of business Social responsibility of business -- Study and teaching Environmental education -- Philosophy Environmental ethics -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1804 , http://hdl.handle.net/10962/d1003689
- Description: This study originates out of my experience as an environmental educator working within business and industry in Zimbabwe and South Africa. It is motivated by my observation that, despite much environmental rhetoric and training, environmental education in industry rarely leads to significant advances towards environmental protection. I assume that the problem of the mismatch between rhetoric and action involves both semiotic and non-semiotic components and therefore, after a thorough exploration of my methodological options, I adopt a qualitative transdisciplinary textual analysis of relevant documents using Fairclough’s Critical Discourse Analysis and Bhaskar’s Dialectical Critical Realism, with some insights taken from Bhaskar’s more recent concept of Meta-Reality. My main conclusions from the study indicate that causally efficacious philosophical mistakes, relating to theories of structure/agency and theories of epistemology, are an important aspect of the problem being considered. Specifically, I demonstrate that these mistakes function to buttress ideology and its attendant contradictions which in turn function to provide the preconditions that maintain inequalities and poor environmental practice in business and industry. Prior and current events, such as climate change and the trend towards globalisation, the ‘free market economy’ and psychological characteristics of the author, relevant to the problem, are also important. In line with Bhaskar’s emancipatory aim for explanatory critique, I end with tentative recommendations for a re-imagined environmental education for business and industry which require (un)action. Consistent with my methodological choices, my recommendations have a (qualified) universal application, despite my focus on texts from South Africa and Zimbabwe. My recommendations are summarised below: • there should be consistency between theory and practice such that performance contradictions are avoided; • we should not act from a fear of survival based on past, no longer relevant experiences (e.g. from childhood) as this is unlikely to be an adequate base for present actions; • we should avoid voluntarism by acting with the resources at our disposal, based on a true understanding of our strengths and weaknesses and our own specificities; • we should avoid assuming the stance of the ‘victim’ by refusing to blame other agents or circumstances, without distorting or underestimating the causal efficacy of those agents or circumstances (related to avoiding voluntarism, whilst nevertheless not resorting to determinism either); • we should direct our action towards the abolition of inequalities and master-slave relationships (related to the avoidance of performance contradictions); • we should act from the position of epistemological humility, rather than from the position of epistemological privilege; • we should consider action as ‘shedding’ based on an understanding of the Transformational Model of Social Activity (TMSA); and • we should consider learning to be ‘shedding’ based on the necessity of (un)knowledge, or ignorance, as a requirement of arriving at relatively new knowledge. This study is also a contribution to contemporary methodological discussions relevant to Critical Discourse Analysis in that it extends these discussions to include psychoanalytical (as well as the more familiar phenomenological and ideological) depth explanations of lived illusion. Furthermore, this study is an experimental attempt to apply the concept of ‘meta-reflexivity’ in Critical Discourse Analysis.
- Full Text:
- Date Issued: 2007
- Authors: Price, Leigh
- Date: 2007
- Subjects: Environmental education Business enterprises -- Environmental aspects Corporations -- Environmental aspects Social responsibility of business Social responsibility of business -- Study and teaching Environmental education -- Philosophy Environmental ethics -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1804 , http://hdl.handle.net/10962/d1003689
- Description: This study originates out of my experience as an environmental educator working within business and industry in Zimbabwe and South Africa. It is motivated by my observation that, despite much environmental rhetoric and training, environmental education in industry rarely leads to significant advances towards environmental protection. I assume that the problem of the mismatch between rhetoric and action involves both semiotic and non-semiotic components and therefore, after a thorough exploration of my methodological options, I adopt a qualitative transdisciplinary textual analysis of relevant documents using Fairclough’s Critical Discourse Analysis and Bhaskar’s Dialectical Critical Realism, with some insights taken from Bhaskar’s more recent concept of Meta-Reality. My main conclusions from the study indicate that causally efficacious philosophical mistakes, relating to theories of structure/agency and theories of epistemology, are an important aspect of the problem being considered. Specifically, I demonstrate that these mistakes function to buttress ideology and its attendant contradictions which in turn function to provide the preconditions that maintain inequalities and poor environmental practice in business and industry. Prior and current events, such as climate change and the trend towards globalisation, the ‘free market economy’ and psychological characteristics of the author, relevant to the problem, are also important. In line with Bhaskar’s emancipatory aim for explanatory critique, I end with tentative recommendations for a re-imagined environmental education for business and industry which require (un)action. Consistent with my methodological choices, my recommendations have a (qualified) universal application, despite my focus on texts from South Africa and Zimbabwe. My recommendations are summarised below: • there should be consistency between theory and practice such that performance contradictions are avoided; • we should not act from a fear of survival based on past, no longer relevant experiences (e.g. from childhood) as this is unlikely to be an adequate base for present actions; • we should avoid voluntarism by acting with the resources at our disposal, based on a true understanding of our strengths and weaknesses and our own specificities; • we should avoid assuming the stance of the ‘victim’ by refusing to blame other agents or circumstances, without distorting or underestimating the causal efficacy of those agents or circumstances (related to avoiding voluntarism, whilst nevertheless not resorting to determinism either); • we should direct our action towards the abolition of inequalities and master-slave relationships (related to the avoidance of performance contradictions); • we should act from the position of epistemological humility, rather than from the position of epistemological privilege; • we should consider action as ‘shedding’ based on an understanding of the Transformational Model of Social Activity (TMSA); and • we should consider learning to be ‘shedding’ based on the necessity of (un)knowledge, or ignorance, as a requirement of arriving at relatively new knowledge. This study is also a contribution to contemporary methodological discussions relevant to Critical Discourse Analysis in that it extends these discussions to include psychoanalytical (as well as the more familiar phenomenological and ideological) depth explanations of lived illusion. Furthermore, this study is an experimental attempt to apply the concept of ‘meta-reflexivity’ in Critical Discourse Analysis.
- Full Text:
- Date Issued: 2007
Academic literacy right from the start?: a critical realist study of the way university literacy is constructed at a Gulf university
- Authors: Picard, Michelle Yvette
- Date: 2007
- Subjects: Gulf University Education, Higher -- Persian Gulf Literacy -- Persian Gulf Academic writing -- Study and teaching -- Persian Gulf English language -- Study and teaching -- Persian Gulf
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1323 , http://hdl.handle.net/10962/d1004121
- Description: The aim of this research was to examine how university literacy is constructed at a university in the Arabian Gulf and to evaluate the appropriateness of this construction where students of a low level of English are exposed to academic English (Right from the Start). Unpacking this construction is a complex task and to gain even a limited insight into the numerous Discourses, epistemologies and pedagogies constituting the construction of university literacy at Gulf universities, a stratified approach that probes the layers of ‘reality’ is necessary. Therefore, a critical realist approach is engaged, along with a variety of methods to probe the layers of the phenomenon. In terms of thesis organization, the traditional empirical structure common to the Social Sciences and the argumentative structure common to the Humanities are integrated. While the information obtained by a variety of methods is analysed and conclusions are reached, this material is also used along with additional literature to support the central contention that university literacy and academic English are possible ‘right from the start’, if the students’ literacy is examined from a certain perspective and if there is an appropriate pedagogy which promotes the desired literacies. This combination of thesis structures would be deemed appropriate in the critical realist ontological framework since the rigour of the thesis lies both in its “reliability” resulting from the empirical data and its focus on the ‘real’; and its “reflexivity” and “persuasivness” arising from the transparently ‘critical’ argument of the thesis (Cadman 2002). In order to conduct the empirical research, the lenses suggested by each of the major views of literacy as outlined by Lea and Street (1998) - namely the “study skills” view, the narrow “academic socialization view” and the “academic literacies view” are utilized in succession. However, the central argument is revealed as the manifestations of each ‘view’ of literacy in the specific context are examined, the research outcomes obtained by utilizing each view in succession are outlined and both are critiqued from the perspective of the “academic literacies” view. Corpus research is undertaken from a “study skills” perspective and the effect of the vocabulary taught to the students on their use of vocabulary in their writing is examined. Also, using the “study skills” lens, the students’ “global language development” in terms of changes or fluctuations in “fluency, accuracy and complexity” (Wolfe-Quintero, Inagaki et al. 1998) over a period of at least three semesters is examined. Utilizing a narrow “academic socialization lens”, studies conducted at the University on learning strategies and motivation and the comments made by respondents in interviews and on an electronic discussion board are compared to comments made by teachers and lecturers. Major flaws in these views of academic literacy are acknowledged and the way each view manifests itself in the Discourse(s) prevalent at this particular university is demonstrated. Finally, Discourses evidenced in the student interviews in particular, are unpacked and then compared and contrasted with those in the lecturer interviews as well as the curriculum and other university documents. The limitations of the study are examined and suggestions for further research and ways to address ‘problems’ associated with university literacy are given.
- Full Text:
- Date Issued: 2007
- Authors: Picard, Michelle Yvette
- Date: 2007
- Subjects: Gulf University Education, Higher -- Persian Gulf Literacy -- Persian Gulf Academic writing -- Study and teaching -- Persian Gulf English language -- Study and teaching -- Persian Gulf
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1323 , http://hdl.handle.net/10962/d1004121
- Description: The aim of this research was to examine how university literacy is constructed at a university in the Arabian Gulf and to evaluate the appropriateness of this construction where students of a low level of English are exposed to academic English (Right from the Start). Unpacking this construction is a complex task and to gain even a limited insight into the numerous Discourses, epistemologies and pedagogies constituting the construction of university literacy at Gulf universities, a stratified approach that probes the layers of ‘reality’ is necessary. Therefore, a critical realist approach is engaged, along with a variety of methods to probe the layers of the phenomenon. In terms of thesis organization, the traditional empirical structure common to the Social Sciences and the argumentative structure common to the Humanities are integrated. While the information obtained by a variety of methods is analysed and conclusions are reached, this material is also used along with additional literature to support the central contention that university literacy and academic English are possible ‘right from the start’, if the students’ literacy is examined from a certain perspective and if there is an appropriate pedagogy which promotes the desired literacies. This combination of thesis structures would be deemed appropriate in the critical realist ontological framework since the rigour of the thesis lies both in its “reliability” resulting from the empirical data and its focus on the ‘real’; and its “reflexivity” and “persuasivness” arising from the transparently ‘critical’ argument of the thesis (Cadman 2002). In order to conduct the empirical research, the lenses suggested by each of the major views of literacy as outlined by Lea and Street (1998) - namely the “study skills” view, the narrow “academic socialization view” and the “academic literacies view” are utilized in succession. However, the central argument is revealed as the manifestations of each ‘view’ of literacy in the specific context are examined, the research outcomes obtained by utilizing each view in succession are outlined and both are critiqued from the perspective of the “academic literacies” view. Corpus research is undertaken from a “study skills” perspective and the effect of the vocabulary taught to the students on their use of vocabulary in their writing is examined. Also, using the “study skills” lens, the students’ “global language development” in terms of changes or fluctuations in “fluency, accuracy and complexity” (Wolfe-Quintero, Inagaki et al. 1998) over a period of at least three semesters is examined. Utilizing a narrow “academic socialization lens”, studies conducted at the University on learning strategies and motivation and the comments made by respondents in interviews and on an electronic discussion board are compared to comments made by teachers and lecturers. Major flaws in these views of academic literacy are acknowledged and the way each view manifests itself in the Discourse(s) prevalent at this particular university is demonstrated. Finally, Discourses evidenced in the student interviews in particular, are unpacked and then compared and contrasted with those in the lecturer interviews as well as the curriculum and other university documents. The limitations of the study are examined and suggestions for further research and ways to address ‘problems’ associated with university literacy are given.
- Full Text:
- Date Issued: 2007
An analysis of oral literary music texts in isiXhosa
- Authors: Mpola, Mavis Noluthando
- Date: 2007
- Subjects: Xhosa (African people) -- Music , Xhosa (African people) -- Music -- History , Xhosa (African people) -- Folklore , Composers, Black -- South Africa , Hymns, Xhosa , Folk literature, Xhosa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3632 , http://hdl.handle.net/10962/d1012909
- Description: This study examines the relationship between composed songs in isiXhosa and the field of oral literature. In traditional Xhosa cultural settings, poetry and music are forms of communal activity enjoyed by that society. Music and poetry perform a special social role in African society in general, providing a critique of socio-economic and political issues. The research analyses the relationship that exists between traditional poetry, izibongo, and composed songs. It demonstrates that in the same way that izibongo can be analysed in order to appreciate the aesthetic value of an oral literary form, the same can be said of composed isiXhosa music. The art of transmitting oral literature is performance. The traditional izibongo are recited before audiences in the same way. Songs (iingoma) stories (amabali) and traditional poetry (izibongo) all comprise oral literature that is transmitted by word of mouth. Opland (1992: 17) says about this type of literature: “Living as it does in the performance is usually appreciated by crowds of people as sounds uttered by the performer who is present before his/her audience.” Opland (ibid 125) again gives an account of who is both reciter of poems and singer of songs. He gives Mthamo’s testimony thus: “He is a singer… with a reputation of being a poet as well.” The musical texts that will be analysed in this thesis will range from those produced as early as 1917, when Benjamin Tyamzashe wrote his first song, Isithandwa sam (My beloved), up to those produced in 1990 when Makhaya Mjana was commissioned by Lovedale on its 150th anniversary to write Qingqa Lovedale (Stand up Lovedale). The song texts total fifty, by twenty-one composers. The texts will be analysed according to different themes, ranging from themes that are metaphoric, themes about events, themes that depict the culture of the amaXhosa, themes with a message of protest, themes demonstrating the relationship between religion and nature, themes that call for unity among the amaXhosa, and themes that depict the personal circumstances of composers and lullabies. The number of texts from each category will vary depending on the composers’ socio-cultural background when they composed the songs. Comparison will be made with some izibongo to show that composers and writers of izibongo are similar artists and, in the words of Mtuze in Izibongo Zomthonyama (1993) “bathwase ngethongo elinye” (They are spiritually gifted in the same way).
- Full Text:
- Date Issued: 2007
- Authors: Mpola, Mavis Noluthando
- Date: 2007
- Subjects: Xhosa (African people) -- Music , Xhosa (African people) -- Music -- History , Xhosa (African people) -- Folklore , Composers, Black -- South Africa , Hymns, Xhosa , Folk literature, Xhosa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3632 , http://hdl.handle.net/10962/d1012909
- Description: This study examines the relationship between composed songs in isiXhosa and the field of oral literature. In traditional Xhosa cultural settings, poetry and music are forms of communal activity enjoyed by that society. Music and poetry perform a special social role in African society in general, providing a critique of socio-economic and political issues. The research analyses the relationship that exists between traditional poetry, izibongo, and composed songs. It demonstrates that in the same way that izibongo can be analysed in order to appreciate the aesthetic value of an oral literary form, the same can be said of composed isiXhosa music. The art of transmitting oral literature is performance. The traditional izibongo are recited before audiences in the same way. Songs (iingoma) stories (amabali) and traditional poetry (izibongo) all comprise oral literature that is transmitted by word of mouth. Opland (1992: 17) says about this type of literature: “Living as it does in the performance is usually appreciated by crowds of people as sounds uttered by the performer who is present before his/her audience.” Opland (ibid 125) again gives an account of who is both reciter of poems and singer of songs. He gives Mthamo’s testimony thus: “He is a singer… with a reputation of being a poet as well.” The musical texts that will be analysed in this thesis will range from those produced as early as 1917, when Benjamin Tyamzashe wrote his first song, Isithandwa sam (My beloved), up to those produced in 1990 when Makhaya Mjana was commissioned by Lovedale on its 150th anniversary to write Qingqa Lovedale (Stand up Lovedale). The song texts total fifty, by twenty-one composers. The texts will be analysed according to different themes, ranging from themes that are metaphoric, themes about events, themes that depict the culture of the amaXhosa, themes with a message of protest, themes demonstrating the relationship between religion and nature, themes that call for unity among the amaXhosa, and themes that depict the personal circumstances of composers and lullabies. The number of texts from each category will vary depending on the composers’ socio-cultural background when they composed the songs. Comparison will be made with some izibongo to show that composers and writers of izibongo are similar artists and, in the words of Mtuze in Izibongo Zomthonyama (1993) “bathwase ngethongo elinye” (They are spiritually gifted in the same way).
- Full Text:
- Date Issued: 2007
An investigation of the key mechanisms that promote whole school development in a secondary school pilot project context
- Authors: Westraad, Susan Fiona
- Date: 2007
- Subjects: Education -- South Africa Education, Secondary -- South Africa Education and state -- South Africa School improvement programs -- South Africa Educational change -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1414 , http://hdl.handle.net/10962/d1003291
- Description: Providing relevant and quality schooling for all South African learners is the paramount goal of the South African National Department of Education. South Africa 's historical and current socio-economic contexts provide many challenges for both the Department of Education and schools in this endeavour to provide quality teaching and learning. These challenges impact directly and indirectly on what happens in the classroom. Since 1994 a plethora of education and training policy has been introduced in South Africa to redress historical imbalances; to introduce a new education and training framework and approach; and to provide guidelines, principles and procedures for addressing some of the challenges that impact on schools. The National Whole School Evaluation Policy provides the legislative framework for the establishment of a quality assurance process in South African schools based on accountability and support. The subsequent Integrated Quality Management System attempts to provide a framework for integrating school evaluation and performance measurement. Policy frameworks are in place to guide quality assurance and school improvement, however, the reality of implementing this at a grass roots level is particularly challenging. The General Motors (GM) South Africa Foundation, a non-governmental development organisation, established by General Motors (GM) South Africa, commenced with the piloting the Learning Schools Initiative to investigate some of the challenges of whole school development and evaluation. This research documents the Learning Schools Initiative's intervention with the initial two pilot secondary schools situated in Port Elizabeth (Nelson Mandela Bay) over a four-year period. It reviews the relevant school reform and school development literature and adopts a critical realist evaluative research approach to investigate the key mechanisms that promote whole school development and change in this context. In keeping with this approach, the results of the research are analysed and discussed within a context-menchanism-outcome configuration that involves the identification of the key mechanisms that bring about desired outcome/s in a specific context. Seven key generative mechanisms are identified as critical at a school and classroom level (i) school culture, (ii) school structures, (iii) effective leadership and management, (iv) personal growth and meaning, (v) restoration of relationships, (vi) professional development of educators, and development of capacity to work together, and (vii) support and accountability. The need to structure school development interventions around the triggering of identified key mechanisms is also identified as an important overarching mechanism. Suggestions are made for further research required to facilitate a deeper understanding of how to bring about meaningful change that results in quality teaching and learning in South African schools.
- Full Text:
- Date Issued: 2007
- Authors: Westraad, Susan Fiona
- Date: 2007
- Subjects: Education -- South Africa Education, Secondary -- South Africa Education and state -- South Africa School improvement programs -- South Africa Educational change -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1414 , http://hdl.handle.net/10962/d1003291
- Description: Providing relevant and quality schooling for all South African learners is the paramount goal of the South African National Department of Education. South Africa 's historical and current socio-economic contexts provide many challenges for both the Department of Education and schools in this endeavour to provide quality teaching and learning. These challenges impact directly and indirectly on what happens in the classroom. Since 1994 a plethora of education and training policy has been introduced in South Africa to redress historical imbalances; to introduce a new education and training framework and approach; and to provide guidelines, principles and procedures for addressing some of the challenges that impact on schools. The National Whole School Evaluation Policy provides the legislative framework for the establishment of a quality assurance process in South African schools based on accountability and support. The subsequent Integrated Quality Management System attempts to provide a framework for integrating school evaluation and performance measurement. Policy frameworks are in place to guide quality assurance and school improvement, however, the reality of implementing this at a grass roots level is particularly challenging. The General Motors (GM) South Africa Foundation, a non-governmental development organisation, established by General Motors (GM) South Africa, commenced with the piloting the Learning Schools Initiative to investigate some of the challenges of whole school development and evaluation. This research documents the Learning Schools Initiative's intervention with the initial two pilot secondary schools situated in Port Elizabeth (Nelson Mandela Bay) over a four-year period. It reviews the relevant school reform and school development literature and adopts a critical realist evaluative research approach to investigate the key mechanisms that promote whole school development and change in this context. In keeping with this approach, the results of the research are analysed and discussed within a context-menchanism-outcome configuration that involves the identification of the key mechanisms that bring about desired outcome/s in a specific context. Seven key generative mechanisms are identified as critical at a school and classroom level (i) school culture, (ii) school structures, (iii) effective leadership and management, (iv) personal growth and meaning, (v) restoration of relationships, (vi) professional development of educators, and development of capacity to work together, and (vii) support and accountability. The need to structure school development interventions around the triggering of identified key mechanisms is also identified as an important overarching mechanism. Suggestions are made for further research required to facilitate a deeper understanding of how to bring about meaningful change that results in quality teaching and learning in South African schools.
- Full Text:
- Date Issued: 2007
Camphor-derived chiral auxiliaries: a synthetic, mechanistic and computational study
- Authors: Duggan, Andrew Robert
- Date: 2007
- Subjects: Camphor Chirality Asymmetric synthesis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4415 , http://hdl.handle.net/10962/d1006772
- Description: A broadly based approach has been undertaken to the development and use of camphor derivatives as chiral auxiliaries in asymmetric synthesis – an approach which has embraced synthetic, mechanistic and computational studies. The unambiguous characterization of mono- and dihydroxy-derivatives, obtained by reduction of chiral camphor ether dimers, has been achieved through detailed one- and two-dimensional NMR spectroscopic analysis. The resulting data has been used to establish both the regio- and stereochemistry of the hydroxyl groups. A camphor-derived cyclic iminolactone has been shown to provide a convenient platform for the synthesis of chiral α-amino acids, stereoselective monoalkylation of the iminolactone affording a range of products in yields of 52 - 65 % with up to 85 % d.e. The attempted development of chiral bifunctional Morita-Baylis-Hillman substrates has revealed an unexpected equilibration between isomeric bornane 2,3-diol monoacrylates via acid-catalysed intramolecular transesterification. A detailed [superscript 1]H NMR-based kinetic study of the rearrangement in various media and at various temperatures has permitted the determination of the kinetic and thermodynamic parameters. A computational study at the DFT level has been used to explore the potential energy surfaces of the acid-catalysed and uncatalysed transesterification of the monoacrylate esters. The theoretical data supports the involvement of cyclic intermediates and has provided a rational basis for predicting the favoured reaction pathways. Novel camphor-derived phenyl sulfonate esters and N-adamantylsulfonamides have been synthesised for use as chiral auxiliaries in the Morita-Baylis-Hillman reaction. Modeling at the Molecular Mechanics level has provided useful insights into possible conformational constraints and an adamantyl sulfonate auxiliary has been successfully used in the stereoselective synthesis of a range of products, generally in excellent yield and with up to 95 % d.e.
- Full Text:
- Date Issued: 2007
- Authors: Duggan, Andrew Robert
- Date: 2007
- Subjects: Camphor Chirality Asymmetric synthesis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4415 , http://hdl.handle.net/10962/d1006772
- Description: A broadly based approach has been undertaken to the development and use of camphor derivatives as chiral auxiliaries in asymmetric synthesis – an approach which has embraced synthetic, mechanistic and computational studies. The unambiguous characterization of mono- and dihydroxy-derivatives, obtained by reduction of chiral camphor ether dimers, has been achieved through detailed one- and two-dimensional NMR spectroscopic analysis. The resulting data has been used to establish both the regio- and stereochemistry of the hydroxyl groups. A camphor-derived cyclic iminolactone has been shown to provide a convenient platform for the synthesis of chiral α-amino acids, stereoselective monoalkylation of the iminolactone affording a range of products in yields of 52 - 65 % with up to 85 % d.e. The attempted development of chiral bifunctional Morita-Baylis-Hillman substrates has revealed an unexpected equilibration between isomeric bornane 2,3-diol monoacrylates via acid-catalysed intramolecular transesterification. A detailed [superscript 1]H NMR-based kinetic study of the rearrangement in various media and at various temperatures has permitted the determination of the kinetic and thermodynamic parameters. A computational study at the DFT level has been used to explore the potential energy surfaces of the acid-catalysed and uncatalysed transesterification of the monoacrylate esters. The theoretical data supports the involvement of cyclic intermediates and has provided a rational basis for predicting the favoured reaction pathways. Novel camphor-derived phenyl sulfonate esters and N-adamantylsulfonamides have been synthesised for use as chiral auxiliaries in the Morita-Baylis-Hillman reaction. Modeling at the Molecular Mechanics level has provided useful insights into possible conformational constraints and an adamantyl sulfonate auxiliary has been successfully used in the stereoselective synthesis of a range of products, generally in excellent yield and with up to 95 % d.e.
- Full Text:
- Date Issued: 2007
Catalytic activities of metallophthalocyanines towards detection and transformation of pollutants
- Authors: Agboola, Bolade Oyeyinka
- Date: 2007
- Subjects: Phthalocyanines Electrochemistry Pollutants -- Biodegradation Pollutants -- Measurement
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4427 , http://hdl.handle.net/10962/d1006922
- Description: Syntheses, spectral, electrochemical and spectroelectrochemical studies of new thiol-derivatised MPc complexes were satisfactorily carried out. For the first time, spectroelectrochemistry gave evidence for the formation of Ni²⁺/Ni⁺ process in a NiPc complex. Significant insights as to the nature of Fe⁺Pc and Ni⁺Pc spectra were obtained. Transformations of chlorophenols using chemical and photochemical methods are presented. For cobalt tetrasulphophthalocyanine catalysed oxidation of chlorophenols using hydrogen peroxide as the oxidant, types of oxidation products formed depended on the solvent conditions. Photolysis of aqueous solutions of chlorophenols in the presence of immobilised non-transition metal phthalocyanine photosensitisers onto Amerlite® was carried out. For the first time, MPcS[subscript mix] complexes were immobilised on Amberlite® for use in heterogeneous photocatalysis. Photolysis of the chlorophenols resulted mainly in the formation of chlorobenzoquinone derivatives. The generation of singlet oxygen (¹O₂) by these immobilised MPc photosensitisers was found to play a major role in their photoactivities. Modifications of gold electrodes with the newly synthesised thiol-derivatised MPc complexes via electropolymerisation and SAM techniques are presented. Cyclic voltammetry, impedance spectroscopy (NiPcs only) and spectroelectrochemical techniques (NiPcs only) confirmed that the complexes formed films on gold electrodes. Stable and well packed SAM films as evidenced by the voltammetric characterisation were obtained. For the first time, optimisation of the time for SAM formation based on CV technique was studied. First example of a formation of MnPc-SAM was achieved. Catalytic activities of the NiPc towards chlorophenol depended on the nature of the NiPc in the polymer films and also anti-fouling ability of the films depended on polymer film thickness. The FeTBMPc polymer modified gold electrode showed the best catalytic activity in terms of peak potential, E[subscript p] when compared to reported work in literature for nitrate electrooxidation. Cyclic voltammetry and spectroscopy studies showed that the CoPcs, FePcs and NiPcs catalysed nitrite oxidation involve 2 electrons in total while that of McPcs involve 1 electron. Better catalytic performance towards sulphite electrooxidation were obtained for the CoPcs, FePcs and MnPcs which have metal based redox processes within the range of the sulphite electrooxidation peak while the NiPcs which did not show metal based oxidation reaction performed less.
- Full Text:
- Date Issued: 2007
- Authors: Agboola, Bolade Oyeyinka
- Date: 2007
- Subjects: Phthalocyanines Electrochemistry Pollutants -- Biodegradation Pollutants -- Measurement
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4427 , http://hdl.handle.net/10962/d1006922
- Description: Syntheses, spectral, electrochemical and spectroelectrochemical studies of new thiol-derivatised MPc complexes were satisfactorily carried out. For the first time, spectroelectrochemistry gave evidence for the formation of Ni²⁺/Ni⁺ process in a NiPc complex. Significant insights as to the nature of Fe⁺Pc and Ni⁺Pc spectra were obtained. Transformations of chlorophenols using chemical and photochemical methods are presented. For cobalt tetrasulphophthalocyanine catalysed oxidation of chlorophenols using hydrogen peroxide as the oxidant, types of oxidation products formed depended on the solvent conditions. Photolysis of aqueous solutions of chlorophenols in the presence of immobilised non-transition metal phthalocyanine photosensitisers onto Amerlite® was carried out. For the first time, MPcS[subscript mix] complexes were immobilised on Amberlite® for use in heterogeneous photocatalysis. Photolysis of the chlorophenols resulted mainly in the formation of chlorobenzoquinone derivatives. The generation of singlet oxygen (¹O₂) by these immobilised MPc photosensitisers was found to play a major role in their photoactivities. Modifications of gold electrodes with the newly synthesised thiol-derivatised MPc complexes via electropolymerisation and SAM techniques are presented. Cyclic voltammetry, impedance spectroscopy (NiPcs only) and spectroelectrochemical techniques (NiPcs only) confirmed that the complexes formed films on gold electrodes. Stable and well packed SAM films as evidenced by the voltammetric characterisation were obtained. For the first time, optimisation of the time for SAM formation based on CV technique was studied. First example of a formation of MnPc-SAM was achieved. Catalytic activities of the NiPc towards chlorophenol depended on the nature of the NiPc in the polymer films and also anti-fouling ability of the films depended on polymer film thickness. The FeTBMPc polymer modified gold electrode showed the best catalytic activity in terms of peak potential, E[subscript p] when compared to reported work in literature for nitrate electrooxidation. Cyclic voltammetry and spectroscopy studies showed that the CoPcs, FePcs and NiPcs catalysed nitrite oxidation involve 2 electrons in total while that of McPcs involve 1 electron. Better catalytic performance towards sulphite electrooxidation were obtained for the CoPcs, FePcs and MnPcs which have metal based redox processes within the range of the sulphite electrooxidation peak while the NiPcs which did not show metal based oxidation reaction performed less.
- Full Text:
- Date Issued: 2007
Causes of persistent rural poverty in Thika district of Kenya, c.1953-2000
- Authors: Kinyanjui, Felistus Kinuna
- Date: 2007
- Subjects: Poverty -- Kenya -- History Rural poor -- Kenya -- History Agriculture -- Kenya -- History Kenya -- History Kenya -- Politics and government
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2547 , http://hdl.handle.net/10962/d1002399
- Description: This study investigates the causes of poverty among the residents of Thika District in Kenya over the period 1953-2000. Using the articulation of modes of production perspective, the study traces the dynamics of poverty to the geography, history and politics of Thika District. The thrust of the argument is that livelihoods in the district changed during the period under investigation, but not necessarily for the better. Landlessness, collapse of the coffee industry, intergenerational poverty, and the ravages of diseases (particularly of HIV/AIDS) are analysed. This leads to the conclusion that causes of poverty in Thika District during the period under examination were complex as one form of deprivation led to another. The study established that poverty in Thika District during the period under review was a product of a process of exclusion from the centre of political power and appropriation. While race was the basis for allocation of public resources in colonial Kenya, ethnicity has dominated the independence period. Consequently, one would have expected the residents of Thika District, the home of Kenya’s first president, Mzee Jomo Kenyatta, to have benefited inordinately from public resources during his rule. Kenyatta’s administration, however, mainly benefited the Kikuyu elite. The study therefore demonstrates that during the period under examination, the Kikuyu, like any other Kenyan community, were a heterogeneous group whose differences were accentuated by class relations. Subaltern groups in Thika District therefore benefited minimally from state patronage, just like similar groups elsewhere in rural Kenya. By the late 1970s, the level of deprivation in rural Kenya had been contained as a result of favourable prices for the country’s agricultural exports. But in the subsequent period, poverty increased under the pressures of world economic recession and slowdowns in trade. The situation was worse for Kikuyu peasants as the Second Republic of President Daniel Moi deliberately attempted undermine the Kikuyu economically. For the majority of Thika residents, this translated into further marginalisation as the Moi regime lumped them together with the Kikuyu elite who had benefitted inordinately from public resources during the Kenyatta era. This study demonstrates that no single factor can explain the prevalence of poverty in Thika District during the period under consideration. However, the poor in the district devised survival mechanisms that could be replicated elsewhere. Indeed, the dynamics of poverty in Thika District represent a microcosm not just for the broader Kenyan situation but also of rural livelihoods elsewhere in the world. The study recommends land reform and horticulture as possible ways of reducing poverty among rural communities. Further, for a successful global war on poverty there is an urgent need to have the West go beyond rhetoric and deliver on its promises to make poverty history.
- Full Text:
- Date Issued: 2007
- Authors: Kinyanjui, Felistus Kinuna
- Date: 2007
- Subjects: Poverty -- Kenya -- History Rural poor -- Kenya -- History Agriculture -- Kenya -- History Kenya -- History Kenya -- Politics and government
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2547 , http://hdl.handle.net/10962/d1002399
- Description: This study investigates the causes of poverty among the residents of Thika District in Kenya over the period 1953-2000. Using the articulation of modes of production perspective, the study traces the dynamics of poverty to the geography, history and politics of Thika District. The thrust of the argument is that livelihoods in the district changed during the period under investigation, but not necessarily for the better. Landlessness, collapse of the coffee industry, intergenerational poverty, and the ravages of diseases (particularly of HIV/AIDS) are analysed. This leads to the conclusion that causes of poverty in Thika District during the period under examination were complex as one form of deprivation led to another. The study established that poverty in Thika District during the period under review was a product of a process of exclusion from the centre of political power and appropriation. While race was the basis for allocation of public resources in colonial Kenya, ethnicity has dominated the independence period. Consequently, one would have expected the residents of Thika District, the home of Kenya’s first president, Mzee Jomo Kenyatta, to have benefited inordinately from public resources during his rule. Kenyatta’s administration, however, mainly benefited the Kikuyu elite. The study therefore demonstrates that during the period under examination, the Kikuyu, like any other Kenyan community, were a heterogeneous group whose differences were accentuated by class relations. Subaltern groups in Thika District therefore benefited minimally from state patronage, just like similar groups elsewhere in rural Kenya. By the late 1970s, the level of deprivation in rural Kenya had been contained as a result of favourable prices for the country’s agricultural exports. But in the subsequent period, poverty increased under the pressures of world economic recession and slowdowns in trade. The situation was worse for Kikuyu peasants as the Second Republic of President Daniel Moi deliberately attempted undermine the Kikuyu economically. For the majority of Thika residents, this translated into further marginalisation as the Moi regime lumped them together with the Kikuyu elite who had benefitted inordinately from public resources during the Kenyatta era. This study demonstrates that no single factor can explain the prevalence of poverty in Thika District during the period under consideration. However, the poor in the district devised survival mechanisms that could be replicated elsewhere. Indeed, the dynamics of poverty in Thika District represent a microcosm not just for the broader Kenyan situation but also of rural livelihoods elsewhere in the world. The study recommends land reform and horticulture as possible ways of reducing poverty among rural communities. Further, for a successful global war on poverty there is an urgent need to have the West go beyond rhetoric and deliver on its promises to make poverty history.
- Full Text:
- Date Issued: 2007
Characterization of WC-VC-Co and WC-VC-TiC-Co hardmetals
- Authors: Hashe, Nobom Gretta
- Date: 2007
- Subjects: Carbides , Hard materials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10533 , http://hdl.handle.net/10948/522 , http://hdl.handle.net/10948/d1011723 , Carbides , Hard materials
- Description: This thesis contains the results of a study focused on cubic carbide and carbonitride grain growth retardation in hardmetals. Large additions of VC, or VC and TiC, or (W,V)C were made to the WC-Co hardmetal, which was then sintered in vacuum or nitrogen. The effectiveness of Ti as the grain growth inhibitor, and the influence of nitrogen sintering on grain coarsening were investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffractrometry (XRD) and atom probe field ion microscope (APFIM). Analysis of vacuum-sintered WC-VC-Co revealed that the cubic carbide grains have a core-rim structure. Ti was found to be a core-rim inhibitor in vacuum-sintered WCVC- TiC-Co. The average cubic carbide grain size distribution for the vacuumsintered materials was narrowed in the Ti-containing hardmetal. The nitrogen-sintered WC-VC-TiC-Co consisted of two phases of cubic carbonitride, one with high Ti-content and the other with high (W,V)-content. The surface region of the nitrogen-sintered WC-VC-TiC-Co was covered with a cubic carbonitride phase. Similar phenomena was observed in nitrogen-sintered WC-VC-Co where two types of carbonitrides were found, those with high V-content and the others with low Vcontent. A gradient zone, consisting of fine WC grains in a Co-rich binder and free from cubic carbonitride grains, was created in the surface region. The nitrogensintered materials consisted of a narrow grain size distribution. The use of (W,V)C as a starting powder affected the mechanical properties of the material with the WC-(W,V)C-Co material being the hardest of those produced in this study. Addition of (W,V)C powder to WC-Co was shown to be the most effective way to limit the cubic carbide grain size during sintering and produce a hard material. The cubic carbide grain size in the material produced this way was the smallest of all studied.
- Full Text:
- Date Issued: 2007
- Authors: Hashe, Nobom Gretta
- Date: 2007
- Subjects: Carbides , Hard materials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10533 , http://hdl.handle.net/10948/522 , http://hdl.handle.net/10948/d1011723 , Carbides , Hard materials
- Description: This thesis contains the results of a study focused on cubic carbide and carbonitride grain growth retardation in hardmetals. Large additions of VC, or VC and TiC, or (W,V)C were made to the WC-Co hardmetal, which was then sintered in vacuum or nitrogen. The effectiveness of Ti as the grain growth inhibitor, and the influence of nitrogen sintering on grain coarsening were investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffractrometry (XRD) and atom probe field ion microscope (APFIM). Analysis of vacuum-sintered WC-VC-Co revealed that the cubic carbide grains have a core-rim structure. Ti was found to be a core-rim inhibitor in vacuum-sintered WCVC- TiC-Co. The average cubic carbide grain size distribution for the vacuumsintered materials was narrowed in the Ti-containing hardmetal. The nitrogen-sintered WC-VC-TiC-Co consisted of two phases of cubic carbonitride, one with high Ti-content and the other with high (W,V)-content. The surface region of the nitrogen-sintered WC-VC-TiC-Co was covered with a cubic carbonitride phase. Similar phenomena was observed in nitrogen-sintered WC-VC-Co where two types of carbonitrides were found, those with high V-content and the others with low Vcontent. A gradient zone, consisting of fine WC grains in a Co-rich binder and free from cubic carbonitride grains, was created in the surface region. The nitrogensintered materials consisted of a narrow grain size distribution. The use of (W,V)C as a starting powder affected the mechanical properties of the material with the WC-(W,V)C-Co material being the hardest of those produced in this study. Addition of (W,V)C powder to WC-Co was shown to be the most effective way to limit the cubic carbide grain size during sintering and produce a hard material. The cubic carbide grain size in the material produced this way was the smallest of all studied.
- Full Text:
- Date Issued: 2007
Clients' views on construction and design team competencies
- Authors: Crafford, Gerrit Jacobus
- Date: 2007
- Subjects: Construction industry -- Employees , Core competencies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9679 , http://hdl.handle.net/10948/490 , Construction industry -- Employees , Core competencies
- Description: The effectiveness of the design and construction team in meeting clients’ requirements entirely depends on the competency proficiency of the design and construction teams. This research presents a model of the important competencies required by the design and construction teams in order to provide a competent service as seen by the client. A review of related literature followed by interviews by selected practitioners yielded 29 architectural competencies, 31 civil engineering competencies, 32 construction management competencies, 31 project management competencies, and 33 quantity surveying competencies that were presented in a structured questionnaire. The questionnaire was completed by 52 developers from a census of developers and municipality managers in South Africa. Respondents were asked to rank or rate: the level of importance of each competency for a career in that specific discipline; how evident that competency is in the specific discipline in South Africa; the level of importance of the performance parameters to clients, and the extent to which the various disciplines realise client satisfaction relative to the various performance parameters. The techniques of re-scaling, principal component analysis, content analysis, ranking and quadrant analysis were applied to the data. Results showed a high degree of consistency among respondents in all disciplines, regardless of the demographic differences in the importance of the competencies. A factor solution was obtained for every discipline using principal component analysis on the important competencies of each discipline. The various factor solutions were in turn used to formulate a simplified model. The model shows that the factors are interdependent and interacting. The model indicates that primary competencies for each profession are supported by mostly secondary competencies. These factors v are in turn influenced by the inter-relationships between the practitioners, continued professional development/ research and universities, which are then in turn, influenced the governing bodies. The local and global environment then ultimately influences the governing bodies. An Importance-Evidence quadrant analysis was undertaken in order to integrate the rankings of the current importance levels and current proficiency levels for each discipline’s competencies, which helped to identify areas in which education and training is immediately needed. Respondents ranked all nine performance parameters above average which indicates that there are more than the traditional performance parameters of cost, quality, and time involved in satisfying clients. The research concluded that vital feedback from clients regarding the competencies required by the respective professionals in the design and construction team was obtained.
- Full Text:
- Date Issued: 2007
- Authors: Crafford, Gerrit Jacobus
- Date: 2007
- Subjects: Construction industry -- Employees , Core competencies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9679 , http://hdl.handle.net/10948/490 , Construction industry -- Employees , Core competencies
- Description: The effectiveness of the design and construction team in meeting clients’ requirements entirely depends on the competency proficiency of the design and construction teams. This research presents a model of the important competencies required by the design and construction teams in order to provide a competent service as seen by the client. A review of related literature followed by interviews by selected practitioners yielded 29 architectural competencies, 31 civil engineering competencies, 32 construction management competencies, 31 project management competencies, and 33 quantity surveying competencies that were presented in a structured questionnaire. The questionnaire was completed by 52 developers from a census of developers and municipality managers in South Africa. Respondents were asked to rank or rate: the level of importance of each competency for a career in that specific discipline; how evident that competency is in the specific discipline in South Africa; the level of importance of the performance parameters to clients, and the extent to which the various disciplines realise client satisfaction relative to the various performance parameters. The techniques of re-scaling, principal component analysis, content analysis, ranking and quadrant analysis were applied to the data. Results showed a high degree of consistency among respondents in all disciplines, regardless of the demographic differences in the importance of the competencies. A factor solution was obtained for every discipline using principal component analysis on the important competencies of each discipline. The various factor solutions were in turn used to formulate a simplified model. The model shows that the factors are interdependent and interacting. The model indicates that primary competencies for each profession are supported by mostly secondary competencies. These factors v are in turn influenced by the inter-relationships between the practitioners, continued professional development/ research and universities, which are then in turn, influenced the governing bodies. The local and global environment then ultimately influences the governing bodies. An Importance-Evidence quadrant analysis was undertaken in order to integrate the rankings of the current importance levels and current proficiency levels for each discipline’s competencies, which helped to identify areas in which education and training is immediately needed. Respondents ranked all nine performance parameters above average which indicates that there are more than the traditional performance parameters of cost, quality, and time involved in satisfying clients. The research concluded that vital feedback from clients regarding the competencies required by the respective professionals in the design and construction team was obtained.
- Full Text:
- Date Issued: 2007
Collaborative research with traditional African health practitioners of the Nelson Mandela Metropole : antimicrobial, anticancer and anti-diabetic activities of five medicinal plants
- Authors: Van Huyssteen, Mea
- Date: 2007
- Subjects: Medicinal plants -- South Africa -- Port Elizabeth , Healers -- South Africa -- Port Elizabeth , Anti-infective agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10148 , http://hdl.handle.net/10948/663 , Medicinal plants -- South Africa -- Port Elizabeth , Healers -- South Africa -- Port Elizabeth , Anti-infective agents
- Description: The promotion and development of indigenous knowledge pertaining to the traditional African healing system is one of the prime objectives set out by the South African government. Despite excellent research opportunities and funding, the biggest problem with ethnopharmacological research is a lack of interaction with indigenous communities, which tends to dilute the benefits this research has to offer these communities. The primary aim of this study was thus to promote the traditional African healing system through collaborative medicinal plant research with local traditional health practitioners. The research collaboration aimed to validate some biological activities of traditional remedies used by collaborating traditional health practitioners and ensured interactive sessions where scientific literature, research practices, findings and relevant legislation were discussed and debated. The joint development of a medicinal garden was a valuable tool in realising these goals. Aqueous and ethanol extracts of Bulbine frutescens, Ornithogalum longibracteatum, Ruta graveolens, Tarchonanthus camphoratus and Tulbaghia violacea were selected for antimicrobial, anticancer and anti-diabetic screening, because of their sustainable utilisation potential. The ethanol extract of T. violacea produced the best antimicrobial activity on Bacillus subtilis (100% growth inhibition) and Candida albicans (89% growth inhibition) at 250 μg/ml. The EC50 for the ethanol extract of T. violacea against HT29 colon cancer cells was 101 μg/ml. The aqueous extracts of B. frutescens and T. camphoratus (0.5 and 50 μg/ml) produced the highest overall glucose uptake activity in Chang liver and C2C12 muscle cells. T. camphoratus was unanimously chosen by participating practitioners as the plant to be investigated further. The aqueous extract of T. camphoratus increased glucose uptake in C2C12 muscle cells through increased translocation of GLUT4 to the plasma membrane and activation of the PI3-kinase and AMP-kinase pathways. It produced some alpha-glucosidase inhibitory activity at concentrations of ≥ 200 μg/ml. Apart from interactive feedback seminars at which the findings were presented to participating practitioners, all scientific literature regarding the plants was summarised, translated, compiled and given to participating practitioners in written format. An indigenous knowledge agreement has been negotiated and will formalise the collaboration in future. It is recommended that future research focuses on plants with economic development potential that can be cultivated in the medicinal garden.
- Full Text:
- Date Issued: 2007
- Authors: Van Huyssteen, Mea
- Date: 2007
- Subjects: Medicinal plants -- South Africa -- Port Elizabeth , Healers -- South Africa -- Port Elizabeth , Anti-infective agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10148 , http://hdl.handle.net/10948/663 , Medicinal plants -- South Africa -- Port Elizabeth , Healers -- South Africa -- Port Elizabeth , Anti-infective agents
- Description: The promotion and development of indigenous knowledge pertaining to the traditional African healing system is one of the prime objectives set out by the South African government. Despite excellent research opportunities and funding, the biggest problem with ethnopharmacological research is a lack of interaction with indigenous communities, which tends to dilute the benefits this research has to offer these communities. The primary aim of this study was thus to promote the traditional African healing system through collaborative medicinal plant research with local traditional health practitioners. The research collaboration aimed to validate some biological activities of traditional remedies used by collaborating traditional health practitioners and ensured interactive sessions where scientific literature, research practices, findings and relevant legislation were discussed and debated. The joint development of a medicinal garden was a valuable tool in realising these goals. Aqueous and ethanol extracts of Bulbine frutescens, Ornithogalum longibracteatum, Ruta graveolens, Tarchonanthus camphoratus and Tulbaghia violacea were selected for antimicrobial, anticancer and anti-diabetic screening, because of their sustainable utilisation potential. The ethanol extract of T. violacea produced the best antimicrobial activity on Bacillus subtilis (100% growth inhibition) and Candida albicans (89% growth inhibition) at 250 μg/ml. The EC50 for the ethanol extract of T. violacea against HT29 colon cancer cells was 101 μg/ml. The aqueous extracts of B. frutescens and T. camphoratus (0.5 and 50 μg/ml) produced the highest overall glucose uptake activity in Chang liver and C2C12 muscle cells. T. camphoratus was unanimously chosen by participating practitioners as the plant to be investigated further. The aqueous extract of T. camphoratus increased glucose uptake in C2C12 muscle cells through increased translocation of GLUT4 to the plasma membrane and activation of the PI3-kinase and AMP-kinase pathways. It produced some alpha-glucosidase inhibitory activity at concentrations of ≥ 200 μg/ml. Apart from interactive feedback seminars at which the findings were presented to participating practitioners, all scientific literature regarding the plants was summarised, translated, compiled and given to participating practitioners in written format. An indigenous knowledge agreement has been negotiated and will formalise the collaboration in future. It is recommended that future research focuses on plants with economic development potential that can be cultivated in the medicinal garden.
- Full Text:
- Date Issued: 2007
Contributions to the use of microalgae in estuarine freshwater reserve determinations
- Authors: Snow, Gavin Charles
- Date: 2007
- Subjects: Microalgae -- South Africa , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10620 , http://hdl.handle.net/10948/709 , Microalgae -- South Africa , Estuarine ecology -- South Africa
- Description: The ecologist Garrett Hardin (1968) introduced a useful concept called the tragedy of the commons, which describes how ecological resources become threatened or lost. The term “commons” is based on the commons of old English villages and is symbolic of a resource that is shared by a group of people. If every person were to use each resource in a sustainable fashion it would be available in perpetuity. However, if people use more than their share they would only increase their personal wealth to the detriment of others. In addition, an increase in the population would mean that the size of each share would have to decrease to accommodate the larger number of people. As a result, resources are threatened by personal greed and uncontrolled population growth. Freshwater is an example of a common resource that is under threat in South Africa where the average annual rainfall is less than 60 percent of the global average (Mukheibir & Sparks 2006). The increasing demands for freshwater as well as its eutrophication are major concerns with regards to estuarine health, environmental resource management and human health. The correct management of water is necessary to ensure that it is utilised in a sustainable manner. The National Water Act (No. 36 of 1998) has provided the rights to water for basic human needs and for sustainable ecological function; the Basic Human Needs Reserve and Ecological Reserve are both provided as a right in law. The amount of water necessary for an estuary to retain an acceptable ecological status, known as the Estuarine Ecological Reserve, is determined through the implementation of procedures (rapid, intermediate or comprehensive) compiled by the Department of Water Affairs and Forestry (1999) in its Resource Directed Measures (RDM) for the Protection of Water Resources. The impact of restricted flow on estuaries can be reduced by manipulating the water released from impoundments, the regulation of water abstractions within the river catchment or both (Hirji et al. 2002). The reserve assessment method is designed to evaluate ecosystem requirements by employing groups of specialists from different disciplines. In South Africa, this includes hydrologists, sedimentologists, water chemists and biologists (including microalgae specialists). The use of microalgae in ecological assessments has largely been based on research that was initiated at the Nelson Mandela Metropolitan University (formerly University of Port Elizabeth) and subsequently at Rhodes University (Grahamstown) and the University of KwaZulu Natal (Durban). The microalgal research can be divided into two main focus areas; phytoplankton and benthic microalgae
- Full Text:
- Date Issued: 2007
- Authors: Snow, Gavin Charles
- Date: 2007
- Subjects: Microalgae -- South Africa , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10620 , http://hdl.handle.net/10948/709 , Microalgae -- South Africa , Estuarine ecology -- South Africa
- Description: The ecologist Garrett Hardin (1968) introduced a useful concept called the tragedy of the commons, which describes how ecological resources become threatened or lost. The term “commons” is based on the commons of old English villages and is symbolic of a resource that is shared by a group of people. If every person were to use each resource in a sustainable fashion it would be available in perpetuity. However, if people use more than their share they would only increase their personal wealth to the detriment of others. In addition, an increase in the population would mean that the size of each share would have to decrease to accommodate the larger number of people. As a result, resources are threatened by personal greed and uncontrolled population growth. Freshwater is an example of a common resource that is under threat in South Africa where the average annual rainfall is less than 60 percent of the global average (Mukheibir & Sparks 2006). The increasing demands for freshwater as well as its eutrophication are major concerns with regards to estuarine health, environmental resource management and human health. The correct management of water is necessary to ensure that it is utilised in a sustainable manner. The National Water Act (No. 36 of 1998) has provided the rights to water for basic human needs and for sustainable ecological function; the Basic Human Needs Reserve and Ecological Reserve are both provided as a right in law. The amount of water necessary for an estuary to retain an acceptable ecological status, known as the Estuarine Ecological Reserve, is determined through the implementation of procedures (rapid, intermediate or comprehensive) compiled by the Department of Water Affairs and Forestry (1999) in its Resource Directed Measures (RDM) for the Protection of Water Resources. The impact of restricted flow on estuaries can be reduced by manipulating the water released from impoundments, the regulation of water abstractions within the river catchment or both (Hirji et al. 2002). The reserve assessment method is designed to evaluate ecosystem requirements by employing groups of specialists from different disciplines. In South Africa, this includes hydrologists, sedimentologists, water chemists and biologists (including microalgae specialists). The use of microalgae in ecological assessments has largely been based on research that was initiated at the Nelson Mandela Metropolitan University (formerly University of Port Elizabeth) and subsequently at Rhodes University (Grahamstown) and the University of KwaZulu Natal (Durban). The microalgal research can be divided into two main focus areas; phytoplankton and benthic microalgae
- Full Text:
- Date Issued: 2007
Development of an in-situ ß-D-Glucuronidase diagnostic moraxella-based biosensor for potential application in the monitoring of water polluted by faecal material in South Africa
- Authors: Togo, Chamunorwa Aloius
- Date: 2007
- Subjects: Water quality management -- South Africa Water quality bioassay -- South Africa Sewage sludge -- South Africa -- Management Water -- Purification -- Biological treatment -- South Africa Biosensors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3947 , http://hdl.handle.net/10962/d1004006
- Description: The prevention of outbreaks of waterborne diseases remains a major challenge to public health service providers globally. One of the major obstacles in this effort is the unavailability of on-line and real-time methods for rapid monitoring of faecal pollution to facilitate early warning of contamination of drinking water. The main objective of this study was to develop a β-glucuronidase (GUD)-based method that could be used for the on-line and real-time monitoring of microbial water quality. GUD is a marker enzyme for the faecal indicator bacteria Escherichia coli. This enzyme breaks down the synthetic substrate p-nitrophenyl-β-D-glucuronide (PNPG) to D-glucuronic acid and p-nitrophenol (PNP), which turns yellow under alkaline pH. The enzymatically produced PNP was used to detect GUD activity. In situ GUD assays were performed using running and stagnant water samples from the Bloukrans River, Grahamstown, South Africa. The physico-chemical properties of environmental GUD were determined, after which a liquid bioprobe and a microbial biosensor modified with Moraxella 1A species for the detection of the enzyme activity were developed. In order to determine the reliability and sensitivity of these methods, regression analyses for each method versus E. coli colony forming units (CFU) were performed. The storage stabilities of the bioprobe and biosensor were also investigated. The physico-chemical properties of in situ GUD were different from those of its commercially available counterpart. The temperature optimum for the former was between 35 and 40 °C while for the latter it was 45 °C. Commercial (reference) GUD had a pH optimum of 8.0 while the environmental counterpart exhibited a broad pH optimum of between pH 5.0 and 8.0. The liquid bioprobe had a limit of detection (LOD) of GUD activity equivalent to 2 CFU/100 ml and a detection time of 24 h. The method was less labour intensive and costly than the culturing method. The liquid bioprobe was stable for at least four weeks at room temperature (20 ± 2 °C). The biosensor was prepared by modifying a glassy carbon electrode with PNP degrading Moraxella 1A cells. The biosensor was 100 times more sensitive and rapid (5-20 min) than the spectrophotometric method (24 h), and was also able to detect GUD activity of viable but non-culturable cells. Thus it was more sensitive than the culturing method. Furthermore, the biosensor was selective and costeffective. The possibility of using a Pseudomonas putida JS444 biosensor was also investigated, but it was not as sensitive and selective as the Moraxella 1A biosensor. The Moraxella biosensor, therefore, offered the best option for on-line and real-time microbial water quality monitoring in South African river waters and drinking water supplies.
- Full Text:
- Date Issued: 2007
- Authors: Togo, Chamunorwa Aloius
- Date: 2007
- Subjects: Water quality management -- South Africa Water quality bioassay -- South Africa Sewage sludge -- South Africa -- Management Water -- Purification -- Biological treatment -- South Africa Biosensors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3947 , http://hdl.handle.net/10962/d1004006
- Description: The prevention of outbreaks of waterborne diseases remains a major challenge to public health service providers globally. One of the major obstacles in this effort is the unavailability of on-line and real-time methods for rapid monitoring of faecal pollution to facilitate early warning of contamination of drinking water. The main objective of this study was to develop a β-glucuronidase (GUD)-based method that could be used for the on-line and real-time monitoring of microbial water quality. GUD is a marker enzyme for the faecal indicator bacteria Escherichia coli. This enzyme breaks down the synthetic substrate p-nitrophenyl-β-D-glucuronide (PNPG) to D-glucuronic acid and p-nitrophenol (PNP), which turns yellow under alkaline pH. The enzymatically produced PNP was used to detect GUD activity. In situ GUD assays were performed using running and stagnant water samples from the Bloukrans River, Grahamstown, South Africa. The physico-chemical properties of environmental GUD were determined, after which a liquid bioprobe and a microbial biosensor modified with Moraxella 1A species for the detection of the enzyme activity were developed. In order to determine the reliability and sensitivity of these methods, regression analyses for each method versus E. coli colony forming units (CFU) were performed. The storage stabilities of the bioprobe and biosensor were also investigated. The physico-chemical properties of in situ GUD were different from those of its commercially available counterpart. The temperature optimum for the former was between 35 and 40 °C while for the latter it was 45 °C. Commercial (reference) GUD had a pH optimum of 8.0 while the environmental counterpart exhibited a broad pH optimum of between pH 5.0 and 8.0. The liquid bioprobe had a limit of detection (LOD) of GUD activity equivalent to 2 CFU/100 ml and a detection time of 24 h. The method was less labour intensive and costly than the culturing method. The liquid bioprobe was stable for at least four weeks at room temperature (20 ± 2 °C). The biosensor was prepared by modifying a glassy carbon electrode with PNP degrading Moraxella 1A cells. The biosensor was 100 times more sensitive and rapid (5-20 min) than the spectrophotometric method (24 h), and was also able to detect GUD activity of viable but non-culturable cells. Thus it was more sensitive than the culturing method. Furthermore, the biosensor was selective and costeffective. The possibility of using a Pseudomonas putida JS444 biosensor was also investigated, but it was not as sensitive and selective as the Moraxella 1A biosensor. The Moraxella biosensor, therefore, offered the best option for on-line and real-time microbial water quality monitoring in South African river waters and drinking water supplies.
- Full Text:
- Date Issued: 2007
Evolutionary and biogeographic studies in the genus Kniphofia moench (Asphodelaceae)
- Authors: Ramdhani, Syd
- Date: 2007
- Subjects: Asphodelaceae Asphodelaceae -- Genetics Cladistic analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4220 , http://hdl.handle.net/10962/d1003789
- Description: Kniphofia, a genus of approximately 71 species, is almost entirely African with two species occurring in Madagascar and one in Yemen. Commonly known as ‘red hot pokers’ they are popular among horticulturists. The genus is also well known for its complex alpha taxonomy. To date, no studies have examined the phylogenetic relationships among species or the evolutionary history of the genus, and little work has been done on their biogeography. The main focus of this study was (i) to review the alpha taxonomy, (ii) to assess diversity and endemism in Kniphofia, (iii) to use DNA sequence data to reconstruct a specieslevel phylogeny to understand intra-generic species relationships and evolutionary processes (iv) to use phylogeographic approaches to study the biogeography and evaluate biogeographical patterns, and (v) to assess anatomical variation and determine if anatomical characters are useful for species delimitation. It was found that the genus has six centres of diversity, five of which are centres of endemism. The South African Centre is the most speciose and is also the largest centre of endemism. Kniphofia shows a strong Afromontane grassland affinity in Tropical and East Africa. In South Africa, it is found from high altitudes to coastal habitats, with the most speciose regions being Afromontane grasslands. It is thus not considered to be an Afromontane element, but rather an Afromontane associate. Five major evolutionary lineages were identified using cpDNA sequence data (trnT-L spacer), four of which are southern African. The fifth lineage is represented by material from Madagascar, East and Tropical Africa. The nuclear ITS region failed to provide resolution, as many sequences were identical. The five lineages recovered using cpDNA showed some congruence with geographic origin rather than the taxonomic arrangement based on morphology. All of the species with multiple samples were non-monophyletic. This could be due to hybridisation and/or incomplete lineage sorting. The nested clade analysis, although preliminary, did not completely agree with the phylogenetic analyses. One of the three third level nested clades appears to show fragmentation between the Cape Region, KwaZulu-Natal and northern parts of southern Africa. Furthermore, another nested clades recovered suggest a range expansion and radiation from the Drakensberg into the adjacent Drakensberg-Maputoland-Pondoland transition. Morphological species of Kniphofia exhibited substantial leaf anatomical variation and anatomical characters do not cluster samples into their morphological species. The anatomical results do not fit any geographic pattern, nor do they correspond to the lineages recovered using molecular markers or the nested clades. Leaf anatomical variation does not appear to be influenced by geographical or environmental factors. However, hybridisation may play a role but was not tested in this study. In light of the above findings it is proposed that the evolutionary and biogeographic history of Kniphofia is strongly linked to tectonic events, and Quaternary climatic cycles and vegetation changes. Tectonic events (viz. uplifts) may have resulted in vicariance events that may account for the five cpDNA lineages recovered in phylogenetic analyses, while Quaternary climatic cycles and vegetation changes may have had a more recent impact on evolution and biogeography. It is hypothesised that the ancestral area for Kniphofia was much more widespread when Afromontane grasslands were more extensive during cooler and drier glacial episodes. Kniphofia on the high mountains of Tropical and East Africa would have tracked Afromontane grasslands as they expanded their ranges in cooler periods. While during wetter and warmer interglacial periods Kniphofia would have retreated into refugia on the mountains of Tropical and East Africa, with no gene flow possible between these refugia. In South Africa, where latitude compensates for altitude, Kniphofia may have maintained a distribution that extended into the lowlands even during interglacials. A cyclic climate change hypothesis implies that populations of Kniphofia (at different phases of the climatic cycle) would have experienced periods of contractions and fragmentation followed by periods of range expansion and coalescence or secondary contact. Altitudinal shifting is proposed to be the most likely mechanism for fragmentation and range expansion, and would would possibly promoted hybridisation. Within the five lineages there is evidence for recent differentiation as the branch lengths are short, there are numerous nonmonophyletic species and numerous identical haplotypes (cpDNA and ITS) which collectively indicate a recent radiation in southern Africa. A recent radiation would also account for the taxonomic confusion and difficulty in differentiating morpho-species. These climatic events may also account for the substantial anatomical variation in southern African Kniphofia species.
- Full Text:
- Date Issued: 2007
- Authors: Ramdhani, Syd
- Date: 2007
- Subjects: Asphodelaceae Asphodelaceae -- Genetics Cladistic analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4220 , http://hdl.handle.net/10962/d1003789
- Description: Kniphofia, a genus of approximately 71 species, is almost entirely African with two species occurring in Madagascar and one in Yemen. Commonly known as ‘red hot pokers’ they are popular among horticulturists. The genus is also well known for its complex alpha taxonomy. To date, no studies have examined the phylogenetic relationships among species or the evolutionary history of the genus, and little work has been done on their biogeography. The main focus of this study was (i) to review the alpha taxonomy, (ii) to assess diversity and endemism in Kniphofia, (iii) to use DNA sequence data to reconstruct a specieslevel phylogeny to understand intra-generic species relationships and evolutionary processes (iv) to use phylogeographic approaches to study the biogeography and evaluate biogeographical patterns, and (v) to assess anatomical variation and determine if anatomical characters are useful for species delimitation. It was found that the genus has six centres of diversity, five of which are centres of endemism. The South African Centre is the most speciose and is also the largest centre of endemism. Kniphofia shows a strong Afromontane grassland affinity in Tropical and East Africa. In South Africa, it is found from high altitudes to coastal habitats, with the most speciose regions being Afromontane grasslands. It is thus not considered to be an Afromontane element, but rather an Afromontane associate. Five major evolutionary lineages were identified using cpDNA sequence data (trnT-L spacer), four of which are southern African. The fifth lineage is represented by material from Madagascar, East and Tropical Africa. The nuclear ITS region failed to provide resolution, as many sequences were identical. The five lineages recovered using cpDNA showed some congruence with geographic origin rather than the taxonomic arrangement based on morphology. All of the species with multiple samples were non-monophyletic. This could be due to hybridisation and/or incomplete lineage sorting. The nested clade analysis, although preliminary, did not completely agree with the phylogenetic analyses. One of the three third level nested clades appears to show fragmentation between the Cape Region, KwaZulu-Natal and northern parts of southern Africa. Furthermore, another nested clades recovered suggest a range expansion and radiation from the Drakensberg into the adjacent Drakensberg-Maputoland-Pondoland transition. Morphological species of Kniphofia exhibited substantial leaf anatomical variation and anatomical characters do not cluster samples into their morphological species. The anatomical results do not fit any geographic pattern, nor do they correspond to the lineages recovered using molecular markers or the nested clades. Leaf anatomical variation does not appear to be influenced by geographical or environmental factors. However, hybridisation may play a role but was not tested in this study. In light of the above findings it is proposed that the evolutionary and biogeographic history of Kniphofia is strongly linked to tectonic events, and Quaternary climatic cycles and vegetation changes. Tectonic events (viz. uplifts) may have resulted in vicariance events that may account for the five cpDNA lineages recovered in phylogenetic analyses, while Quaternary climatic cycles and vegetation changes may have had a more recent impact on evolution and biogeography. It is hypothesised that the ancestral area for Kniphofia was much more widespread when Afromontane grasslands were more extensive during cooler and drier glacial episodes. Kniphofia on the high mountains of Tropical and East Africa would have tracked Afromontane grasslands as they expanded their ranges in cooler periods. While during wetter and warmer interglacial periods Kniphofia would have retreated into refugia on the mountains of Tropical and East Africa, with no gene flow possible between these refugia. In South Africa, where latitude compensates for altitude, Kniphofia may have maintained a distribution that extended into the lowlands even during interglacials. A cyclic climate change hypothesis implies that populations of Kniphofia (at different phases of the climatic cycle) would have experienced periods of contractions and fragmentation followed by periods of range expansion and coalescence or secondary contact. Altitudinal shifting is proposed to be the most likely mechanism for fragmentation and range expansion, and would would possibly promoted hybridisation. Within the five lineages there is evidence for recent differentiation as the branch lengths are short, there are numerous nonmonophyletic species and numerous identical haplotypes (cpDNA and ITS) which collectively indicate a recent radiation in southern Africa. A recent radiation would also account for the taxonomic confusion and difficulty in differentiating morpho-species. These climatic events may also account for the substantial anatomical variation in southern African Kniphofia species.
- Full Text:
- Date Issued: 2007