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 theory-based approach to evaluating a Continuing Teacher Professional Development Programme aimed at strengthening environment and sustainability education
- Authors: Songqwaru, Nonyameko Zintle
- Date: 2020
- Subjects: Fundisa for Change , Environmental education -- South Africa , Teachers -- Training of -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145267 , vital:38423
- Description: This study uses a theory-based approach to evaluate the Fundisa for Change training programme, a continuing teacher professional development programme aimed at strengthening environment and sustainability education. The aim of the study was to surface assumptions that underpin the design and implementation of the Fundisa for Change training programme. The Fundisa for Change Teacher Education programme is a national collaborative programme that is implemented in all the nine provinces of South Africa. The study reports on the implementation of the programme in five provinces. The study aimed to surface the Fundisa for Change training programme’s implementation theory and programme theory as these affect programme delivery. The Fundisa for Change training programme was implemented in diverse contexts by different facilitators to different participants. To determine how training programme outcomes were achieved, use was made of context-mechanism-outcome (CMO) configurations for each site where the programme was implemented. Data used to construct CMO configurations was generated through document analysis of Fundisa for Change documents, interviews with stakeholders and participants, as well as observations of programme implementation at five sites. There were three phases to data analysis: content analysis of Fundisa for Change documents, content analysis of observation transcripts and use of the CMO configuration, an analytical tool used in realist evaluation. An initial CMO configuration was constructed prior to observing implementation of the programme and a refined CMO configuration for the Fundisa for Change training programme was constructed based on similarities between the CMO configurations constructed for each of the five sites under study. The partnership model of the Fundisa for Change training programme brought diverse expertise and resources (material, cognitive, social and emotional) which were conducive to the achievement of programme outcomes. The programme’s action context (structure, culture, agency and relations) contributed to the achievement of programme outcomes by participants. Participants’ subject content knowledge, teaching practice and assessment practice was enhanced through attending the Fundisa for Change training. On-course tasks were mediated during training and this created opportunities for participants to discuss and reflect on current practice in ways that could lead to a change in practice. In evaluating professional development programmes, an elaborated definition of context in terms of structure, culture, agency and relations enables a comprehensive exploration of potential programme mechanisms that can be activated when programmes are implemented. It is also important to disaggregate resources and reasons when identifying mechanisms as this assists with differentiating between context and mechanisms. The study offers insights into the professional learning of teachers grappling with new content and pedagogical content knowledges related to environment in the context of recent curriculum changes where the South African national school curriculum has come into focus. Environmental education programmes in South Africa have implicitly used a realist approach. This study offers the first substantive professional learning evaluation that develops this approach explicitly using Theory of Change and Realist Evaluation in combination.
- Full Text:
- Date Issued: 2020
- Authors: Songqwaru, Nonyameko Zintle
- Date: 2020
- Subjects: Fundisa for Change , Environmental education -- South Africa , Teachers -- Training of -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145267 , vital:38423
- Description: This study uses a theory-based approach to evaluate the Fundisa for Change training programme, a continuing teacher professional development programme aimed at strengthening environment and sustainability education. The aim of the study was to surface assumptions that underpin the design and implementation of the Fundisa for Change training programme. The Fundisa for Change Teacher Education programme is a national collaborative programme that is implemented in all the nine provinces of South Africa. The study reports on the implementation of the programme in five provinces. The study aimed to surface the Fundisa for Change training programme’s implementation theory and programme theory as these affect programme delivery. The Fundisa for Change training programme was implemented in diverse contexts by different facilitators to different participants. To determine how training programme outcomes were achieved, use was made of context-mechanism-outcome (CMO) configurations for each site where the programme was implemented. Data used to construct CMO configurations was generated through document analysis of Fundisa for Change documents, interviews with stakeholders and participants, as well as observations of programme implementation at five sites. There were three phases to data analysis: content analysis of Fundisa for Change documents, content analysis of observation transcripts and use of the CMO configuration, an analytical tool used in realist evaluation. An initial CMO configuration was constructed prior to observing implementation of the programme and a refined CMO configuration for the Fundisa for Change training programme was constructed based on similarities between the CMO configurations constructed for each of the five sites under study. The partnership model of the Fundisa for Change training programme brought diverse expertise and resources (material, cognitive, social and emotional) which were conducive to the achievement of programme outcomes. The programme’s action context (structure, culture, agency and relations) contributed to the achievement of programme outcomes by participants. Participants’ subject content knowledge, teaching practice and assessment practice was enhanced through attending the Fundisa for Change training. On-course tasks were mediated during training and this created opportunities for participants to discuss and reflect on current practice in ways that could lead to a change in practice. In evaluating professional development programmes, an elaborated definition of context in terms of structure, culture, agency and relations enables a comprehensive exploration of potential programme mechanisms that can be activated when programmes are implemented. It is also important to disaggregate resources and reasons when identifying mechanisms as this assists with differentiating between context and mechanisms. The study offers insights into the professional learning of teachers grappling with new content and pedagogical content knowledges related to environment in the context of recent curriculum changes where the South African national school curriculum has come into focus. Environmental education programmes in South Africa have implicitly used a realist approach. This study offers the first substantive professional learning evaluation that develops this approach explicitly using Theory of Change and Realist Evaluation in combination.
- Full Text:
- Date Issued: 2020
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
A victimological study among Coloureds in the Cape Peninsula
- Authors: Strijdom, Hendrik Gert
- Date: 1983
- Subjects: Victims of crimes -- South Africa -- Western Cape Colored people (South Africa) -- Social conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3342 , http://hdl.handle.net/10962/d1004582
- Description: From Introduction: Criminology developed as a reaction to the various revolutions that were occurring in the European countries during the eighteenth and nineteenth centuries. In response to the turmoil and disorder of Western society criminologists attempted to discover the natural laws of society hoping to establish a stable social order. Crime was regarded as something that disturbed society and, therefore, had to be controlled or prevented. According to Quinney and Wildeman (1977) the development of criminology can be viewed as an ongoing attempt to explain crime in terms of established social order. They state that in the history of criminology there is, however, a lack of a clear accumulative theoretical growth and continue as follows: "No line of theoretical development can be found that leads to a well-developed body of knowledge. The study of crime is characterized by a number of divergent theoretical perspectives that exist in relative isolation from one another" (p. 38). Quinney and Wildeman (1977) distinguish five theoretical perspectives in the development of criminology namely: (I) early and classical criminological thought, (2) nineteenth-century sociological criminology, (3) nineteenth-century biological criminology, (4) twentieth-century eclectic criminology, and (5) twentieth-century sociological criminology.
- Full Text:
- Date Issued: 1983
- Authors: Strijdom, Hendrik Gert
- Date: 1983
- Subjects: Victims of crimes -- South Africa -- Western Cape Colored people (South Africa) -- Social conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3342 , http://hdl.handle.net/10962/d1004582
- Description: From Introduction: Criminology developed as a reaction to the various revolutions that were occurring in the European countries during the eighteenth and nineteenth centuries. In response to the turmoil and disorder of Western society criminologists attempted to discover the natural laws of society hoping to establish a stable social order. Crime was regarded as something that disturbed society and, therefore, had to be controlled or prevented. According to Quinney and Wildeman (1977) the development of criminology can be viewed as an ongoing attempt to explain crime in terms of established social order. They state that in the history of criminology there is, however, a lack of a clear accumulative theoretical growth and continue as follows: "No line of theoretical development can be found that leads to a well-developed body of knowledge. The study of crime is characterized by a number of divergent theoretical perspectives that exist in relative isolation from one another" (p. 38). Quinney and Wildeman (1977) distinguish five theoretical perspectives in the development of criminology namely: (I) early and classical criminological thought, (2) nineteenth-century sociological criminology, (3) nineteenth-century biological criminology, (4) twentieth-century eclectic criminology, and (5) twentieth-century sociological criminology.
- Full Text:
- Date Issued: 1983
Abstract and lifelike experimental games
- Authors: Colman, Andrew Michael
- Date: 1980
- Subjects: Game theory Social psychology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3137 , http://hdl.handle.net/10962/d1006958
- Description: The theory of games seems to me to provide the most promising alternative to the traditional theories of social behaviour. Gaming modelS are inherently social in character (an individual's strategy choice in a game cannot even be properly defined without reference to at least one other individual) and they represent a radical departure from the "social stimulus - individual response" approach. They sean, furthermore, to be the only models which can adequately conceptualize an important (and large) class of social behaviours which arise from deliberate free choice. (From preface)
- Full Text:
- Date Issued: 1980
- Authors: Colman, Andrew Michael
- Date: 1980
- Subjects: Game theory Social psychology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3137 , http://hdl.handle.net/10962/d1006958
- Description: The theory of games seems to me to provide the most promising alternative to the traditional theories of social behaviour. Gaming modelS are inherently social in character (an individual's strategy choice in a game cannot even be properly defined without reference to at least one other individual) and they represent a radical departure from the "social stimulus - individual response" approach. They sean, furthermore, to be the only models which can adequately conceptualize an important (and large) class of social behaviours which arise from deliberate free choice. (From preface)
- Full Text:
- Date Issued: 1980
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
Access to land as a human right the payment of just and equitable compensation for dispossessed land in South Africa
- Authors: Yanou, Michael A
- Date: 2005
- Subjects: Human rights -- South Africa , Compensation (Law) -- South Africa , Right of property -- South Africa , Land reform -- South Africa , Land tenure -- South Africa , Constitutional history -- South Africa , Restitution -- South Africa , Land tenure -- Law and legislation -- South Africa , Land reform -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3699 , http://hdl.handle.net/10962/d1003214 , Human rights -- South Africa , Compensation (Law) -- South Africa , Right of property -- South Africa , Land reform -- South Africa , Land tenure -- South Africa , Constitutional history -- South Africa , Restitution -- South Africa , Land tenure -- Law and legislation -- South Africa , Land reform -- Law and legislation -- South Africa
- Description: This thesis deals with the conceptualization of access to land by the dispossessed as a human right and commences with an account of the struggle for land between the peoples of African and European extractions in South Africa. It is observed that the latter assumed sovereignty over the ancestral lands of the former. The thesis discusses the theoretical foundation of the study and situates the topic within its conceptual parameters. The writer examines the notions of justice and equity in the context of the post apartheid constitutional mandate to redress the skewed policy of the past. It is argued that the dispossession of Africans from lands that they had possessed for thousands of years on the assumption that the land was terra nullius was profoundly iniquitous and unjust. Although the study is technically limited to dispossessions occurring on or after the 13th June 1913, it covers a fairly extensive account of dispossession predating this date. This historical analysis is imperative for two reasons. Besides supporting the writer’s contention that the limitation of restitution to land dispossessed on or after 1913 was arbitrary, it also highlights both the material and non-material cost of the devastating wars of dispossessions. The candidate comments extensively on the post apartheid constitutional property structure which was conceived as a redress to the imbalance created by dispossession. This underlying objective explains why the state’s present land policy is geared towards facilitating access to land for the landless. The thesis investigates the extent to which the present property structure which defines access to land as a human right has succeeded in achieving the stated objective. It reviews the strengths and weaknesses of the land restitution process as well as the question of the payment of just and equitable compensation for land expropriated for restitution. The latter was carefully examined because it plays a crucial role in the success or otherwise of the restitution scheme. The writer argues that the courts have, on occasions, construed just and equitable compensation generously. This approach has failed to reflect the moral component inherent in the Aristotelian corrective justice. This, in the context of South Africa, requires compensation to reflect the fact that what is being paid for is land dispossessed from the forebears of indigenous inhabitants. It seems obvious that the scales of justice are tilted heavily in favour of the propertied class whose ancestors were responsible for this dispossession. This has a ripple effect on the pace of the restitution process. It also seems to have the effect of favouring the property class at the expense of the entire restitution process. The candidate also comments on the court’s differing approaches to the interpretation of the constitutional property clause. The candidate contends that the construction of the property clause and related pieces of legislation in a manner that stresses the maintenance of a balance between private property interest and land reform is flawed. This contention is supported by the fact that these values do not have proportional worth in the present property context of South Africa. The narrow definition of “past racially discriminatory law and practices” and labour tenant as used in the relevant post apartheid land reform laws is criticized for the same reason of its uncontextual approach. A comparative appraisal of similar developments relating to property law in other societies like India and Zimbabwe has been done. The writer has treated the post reform land evictions as a form of dispossession. The candidate notes that the country should guard against allowing the disastrous developments in Zimbabwe to influence events in the country and calls for an amendment of the property clause of the constitution in response to the practical difficulties which a decade of the operation of the current constitution has revealed.
- Full Text:
- Date Issued: 2005
- Authors: Yanou, Michael A
- Date: 2005
- Subjects: Human rights -- South Africa , Compensation (Law) -- South Africa , Right of property -- South Africa , Land reform -- South Africa , Land tenure -- South Africa , Constitutional history -- South Africa , Restitution -- South Africa , Land tenure -- Law and legislation -- South Africa , Land reform -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3699 , http://hdl.handle.net/10962/d1003214 , Human rights -- South Africa , Compensation (Law) -- South Africa , Right of property -- South Africa , Land reform -- South Africa , Land tenure -- South Africa , Constitutional history -- South Africa , Restitution -- South Africa , Land tenure -- Law and legislation -- South Africa , Land reform -- Law and legislation -- South Africa
- Description: This thesis deals with the conceptualization of access to land by the dispossessed as a human right and commences with an account of the struggle for land between the peoples of African and European extractions in South Africa. It is observed that the latter assumed sovereignty over the ancestral lands of the former. The thesis discusses the theoretical foundation of the study and situates the topic within its conceptual parameters. The writer examines the notions of justice and equity in the context of the post apartheid constitutional mandate to redress the skewed policy of the past. It is argued that the dispossession of Africans from lands that they had possessed for thousands of years on the assumption that the land was terra nullius was profoundly iniquitous and unjust. Although the study is technically limited to dispossessions occurring on or after the 13th June 1913, it covers a fairly extensive account of dispossession predating this date. This historical analysis is imperative for two reasons. Besides supporting the writer’s contention that the limitation of restitution to land dispossessed on or after 1913 was arbitrary, it also highlights both the material and non-material cost of the devastating wars of dispossessions. The candidate comments extensively on the post apartheid constitutional property structure which was conceived as a redress to the imbalance created by dispossession. This underlying objective explains why the state’s present land policy is geared towards facilitating access to land for the landless. The thesis investigates the extent to which the present property structure which defines access to land as a human right has succeeded in achieving the stated objective. It reviews the strengths and weaknesses of the land restitution process as well as the question of the payment of just and equitable compensation for land expropriated for restitution. The latter was carefully examined because it plays a crucial role in the success or otherwise of the restitution scheme. The writer argues that the courts have, on occasions, construed just and equitable compensation generously. This approach has failed to reflect the moral component inherent in the Aristotelian corrective justice. This, in the context of South Africa, requires compensation to reflect the fact that what is being paid for is land dispossessed from the forebears of indigenous inhabitants. It seems obvious that the scales of justice are tilted heavily in favour of the propertied class whose ancestors were responsible for this dispossession. This has a ripple effect on the pace of the restitution process. It also seems to have the effect of favouring the property class at the expense of the entire restitution process. The candidate also comments on the court’s differing approaches to the interpretation of the constitutional property clause. The candidate contends that the construction of the property clause and related pieces of legislation in a manner that stresses the maintenance of a balance between private property interest and land reform is flawed. This contention is supported by the fact that these values do not have proportional worth in the present property context of South Africa. The narrow definition of “past racially discriminatory law and practices” and labour tenant as used in the relevant post apartheid land reform laws is criticized for the same reason of its uncontextual approach. A comparative appraisal of similar developments relating to property law in other societies like India and Zimbabwe has been done. The writer has treated the post reform land evictions as a form of dispossession. The candidate notes that the country should guard against allowing the disastrous developments in Zimbabwe to influence events in the country and calls for an amendment of the property clause of the constitution in response to the practical difficulties which a decade of the operation of the current constitution has revealed.
- Full Text:
- Date Issued: 2005
Accident liability and primary process thinking : a study in ego psychology
- Authors: Nell, Oelrich
- Date: 1975
- Subjects: Automobile drivers -- Psychology , Ego (Psychology) , Traffic safety -- South Africa -- Psychological aspects , Liability for traffic accidents -- South Africa , Traffic accidents -- South Africa -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3220 , http://hdl.handle.net/10962/d1012950
- Description: Serious efforts must be made to combat the high accident rate on the roads in the Republic of South Africa. The same spirit which exists in the field of medicine when there are evidences that an epidemic is beginning to take its toll, must come into being amongst those who are concerned with traffic and its problems. The public itself needs to become more aware of road safety. Many associations and institutions have been created to assist with the inculcation of the road safety ideal. The National Road Safety Council, which creates opportunities for investigation into aspects of road safety must continue to expand its sphere of influence. The research project contained on the following pages represents an attempt to contribute to the human factor in traffic safety, particularly by making a closer study of the driver of the motor vehicle. The writer is concerned with the carnage that is caused by road accidents. His previous study of personality and particularly of the projective techniques of assessment has prompted a consideration of the problem.
- Full Text:
- Date Issued: 1975
- Authors: Nell, Oelrich
- Date: 1975
- Subjects: Automobile drivers -- Psychology , Ego (Psychology) , Traffic safety -- South Africa -- Psychological aspects , Liability for traffic accidents -- South Africa , Traffic accidents -- South Africa -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3220 , http://hdl.handle.net/10962/d1012950
- Description: Serious efforts must be made to combat the high accident rate on the roads in the Republic of South Africa. The same spirit which exists in the field of medicine when there are evidences that an epidemic is beginning to take its toll, must come into being amongst those who are concerned with traffic and its problems. The public itself needs to become more aware of road safety. Many associations and institutions have been created to assist with the inculcation of the road safety ideal. The National Road Safety Council, which creates opportunities for investigation into aspects of road safety must continue to expand its sphere of influence. The research project contained on the following pages represents an attempt to contribute to the human factor in traffic safety, particularly by making a closer study of the driver of the motor vehicle. The writer is concerned with the carnage that is caused by road accidents. His previous study of personality and particularly of the projective techniques of assessment has prompted a consideration of the problem.
- Full Text:
- Date Issued: 1975
Accountability in the global health regime : a critical examination of the institutional policy and practice of the global fund to fight HIV/AIDS, tuberculosis and malaria partnership programme in Ghana
- Authors: Onokwai, John Chukwuemeka
- Date: 2021-04
- Subjects: World health , Global Fund to Fight AIDS, Tuberculosis, and Malaria -- Administration , Public-private sector cooperation -- Political aspects , Public-private sector cooperation -- Social aspects , Public-private sector cooperation -- Administration , Medical policy -- Ghana , Public health laws, International , Ghana -- Social conditions
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177099 , vital:42790 , 10.21504/10962/177099
- Description: The overarching objective of this thesis is to undertake a critical examination of the institutional accountability policy and practice of the Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund) in the context of its partnership programme in Ghana. The Global Fund is a global public-private partnership (GPPP) in health engaged in public health policy processes worldwide. As a GPPP, the policy mandate that underpins its global response to fight the aforementioned diseases requires it to enter into partnerships with recipient countries to finance their national health policy responses and strategies to tackle these diseases. Situating accountability within the context of the shift from an international health to a global health regime, the study argues that the emergence of GPPPs in health and the formal policy mandate and decision-making powers they exercise have had knock-on consequences for understanding accountability in the global health regime. This is because while the understanding of accountability for public health policy processes in the international health regime revolved solely around state-based and state-led accountability processes, it is no longer so in current global health regime. Since these GPPPs are not states, they derive their understanding of accountability from the nature and character of their individual policy and practice arrangements. However, despite contestation around the Global Fund’s accountability in global health literature, this literature has little to say on the question of how the Global Fund itself (as a partnership organisation) understands accountability in policy and how this understanding informs its practice in specific settings of global health. Thus, this study contributes to literature on GPPPs’ accountability in global health by specifically exploring how the Global Fund understands accountability in policy and how this understanding informs its accountability in practice, in particular in relationship to its implications for country ownership of health policy in Ghana. Drawing on fieldwork undertaken in Ghana, and guided by a critical political economy approach, this study will demonstrate how: 1) the Global Fund’s institutional policy and practice arrangements undermine accountability to the government and to those affected by their activities; 2) the Global Fund’s practice of country ownership is reflective of conditional ownership despite the fact that the Global Fund claims to promote country ownership as a core principle of its accountability practice in aid recipient countries; and 3) the accountability policy and practice instruments of the Global Fund are not politically neutral, but are rather a function of relations of power. To improve the ability of Ghana (and other recipient countries) to own their developmental policies, a reordering of global economic relations is needed, with a renewed emphasis and focus on economic justice and human rights. Such a reordering will improve the material capabilities (control of and access to global centres of production, finance and technology) of aid recipient countries. This will empower Ghana (and other recipient countries) to play a more dominant, rather than a subsidiary role in how the global health landscape is organised and financed and in policy processes undertaken by global health policy institutions like the Global Fund. In this way, Ghana (and other developing countries) will be able to limit and mitigate the dominance and influence of powerful donors who shape the institutional policy and practice arrangements of global health policy institutions like the Global Fund. , Thesis (PhD) -- Faculty of Humanities, Department of Political and International Studies, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Onokwai, John Chukwuemeka
- Date: 2021-04
- Subjects: World health , Global Fund to Fight AIDS, Tuberculosis, and Malaria -- Administration , Public-private sector cooperation -- Political aspects , Public-private sector cooperation -- Social aspects , Public-private sector cooperation -- Administration , Medical policy -- Ghana , Public health laws, International , Ghana -- Social conditions
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177099 , vital:42790 , 10.21504/10962/177099
- Description: The overarching objective of this thesis is to undertake a critical examination of the institutional accountability policy and practice of the Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund) in the context of its partnership programme in Ghana. The Global Fund is a global public-private partnership (GPPP) in health engaged in public health policy processes worldwide. As a GPPP, the policy mandate that underpins its global response to fight the aforementioned diseases requires it to enter into partnerships with recipient countries to finance their national health policy responses and strategies to tackle these diseases. Situating accountability within the context of the shift from an international health to a global health regime, the study argues that the emergence of GPPPs in health and the formal policy mandate and decision-making powers they exercise have had knock-on consequences for understanding accountability in the global health regime. This is because while the understanding of accountability for public health policy processes in the international health regime revolved solely around state-based and state-led accountability processes, it is no longer so in current global health regime. Since these GPPPs are not states, they derive their understanding of accountability from the nature and character of their individual policy and practice arrangements. However, despite contestation around the Global Fund’s accountability in global health literature, this literature has little to say on the question of how the Global Fund itself (as a partnership organisation) understands accountability in policy and how this understanding informs its practice in specific settings of global health. Thus, this study contributes to literature on GPPPs’ accountability in global health by specifically exploring how the Global Fund understands accountability in policy and how this understanding informs its accountability in practice, in particular in relationship to its implications for country ownership of health policy in Ghana. Drawing on fieldwork undertaken in Ghana, and guided by a critical political economy approach, this study will demonstrate how: 1) the Global Fund’s institutional policy and practice arrangements undermine accountability to the government and to those affected by their activities; 2) the Global Fund’s practice of country ownership is reflective of conditional ownership despite the fact that the Global Fund claims to promote country ownership as a core principle of its accountability practice in aid recipient countries; and 3) the accountability policy and practice instruments of the Global Fund are not politically neutral, but are rather a function of relations of power. To improve the ability of Ghana (and other recipient countries) to own their developmental policies, a reordering of global economic relations is needed, with a renewed emphasis and focus on economic justice and human rights. Such a reordering will improve the material capabilities (control of and access to global centres of production, finance and technology) of aid recipient countries. This will empower Ghana (and other recipient countries) to play a more dominant, rather than a subsidiary role in how the global health landscape is organised and financed and in policy processes undertaken by global health policy institutions like the Global Fund. In this way, Ghana (and other developing countries) will be able to limit and mitigate the dominance and influence of powerful donors who shape the institutional policy and practice arrangements of global health policy institutions like the Global Fund. , Thesis (PhD) -- Faculty of Humanities, Department of Political and International Studies, 2021
- Full Text:
- Date Issued: 2021-04
Activity of diverse chalcones against several targets: statistical analysis of a high-throughput virtual screen of a custom chalcone library
- Authors: Sarron, Arthur F D
- Date: 2020
- Subjects: Acetophenone , Benzaldehyde , Ketones , Pyruvate kinase , Drug development , Aromatic compounds , Heat shock proteins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/116028 , vital:34291
- Description: Chalcone family molecules are well known to have therapeutic proprieties (anti-inflammatory, anti-microbial or anti-cancer, etc). However the mechanism of action in some cases is not well known. A virtual library of this family of compounds was constructed using custom scripts, based on the aldol condensation, and this library was modified further to analogues by expansion of the α,β-unsaturated ketone linker. Acetophenone and benzaldehyde derivatives which are available and purchasable were used as a base to design the chalcone virtual library. 8063 chalcones were constructed and geometrically optimized with Gaussian 09. Their physicochemical characteristics linked to the Lipinski rules were analyzed with Knime and CDK. The entire library was after docked against several targets including HIV-1 integrase, MRSA pyruvate kinase, HSP90, COX-1, COX-2, ALR2, MAOA, MAOB, acetylcholinesterase, butyrylcholinesterase and PLA2. With the exception of MAOA, which does not have a crystal structure ligand, all dockings were validated by redocking the original ligand provided by the literature. These targets are known in the literature to be inhibited by chalcone-derivatives. However, specificity of the particular known chalcone inhibitors to the particular targets is not known. To this end the performance of the generated chalcone library against the list of targets was of interest. The binding energy of ligand-protein complexes was generally good across the library. Statistical analysis including principal component analysis and hierarchical clustering analysis were made in order to investigate for any physical/chemical characteristics which might explain what chalcone features affect the binding energy of the ligand-protein complexes. The spherical polar coordinates defining the orientation of the binding poses were also calculated and used in the statistical analysis. The statistical analysis has allowed us to hypothesize the importance of these radial distances and the polar angles of key atoms in the chalcones in binding to the pyruvate kinase crystal structure. This was validated by the docking of another small library of compound models in which the α,β-unsaturated ketone chain of the chalcone was replaced by incrementally longer conjugated chains. Further studies on the chalcones themselves reveal rotameric systems in both cis and trans-configurations (which may impact binding), and also studied was the effect of Topliss-based modification and its impact of binding to HSP90. Molecular dynamics confirmed good binding of identified chalcone hits.
- Full Text:
- Date Issued: 2020
- Authors: Sarron, Arthur F D
- Date: 2020
- Subjects: Acetophenone , Benzaldehyde , Ketones , Pyruvate kinase , Drug development , Aromatic compounds , Heat shock proteins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/116028 , vital:34291
- Description: Chalcone family molecules are well known to have therapeutic proprieties (anti-inflammatory, anti-microbial or anti-cancer, etc). However the mechanism of action in some cases is not well known. A virtual library of this family of compounds was constructed using custom scripts, based on the aldol condensation, and this library was modified further to analogues by expansion of the α,β-unsaturated ketone linker. Acetophenone and benzaldehyde derivatives which are available and purchasable were used as a base to design the chalcone virtual library. 8063 chalcones were constructed and geometrically optimized with Gaussian 09. Their physicochemical characteristics linked to the Lipinski rules were analyzed with Knime and CDK. The entire library was after docked against several targets including HIV-1 integrase, MRSA pyruvate kinase, HSP90, COX-1, COX-2, ALR2, MAOA, MAOB, acetylcholinesterase, butyrylcholinesterase and PLA2. With the exception of MAOA, which does not have a crystal structure ligand, all dockings were validated by redocking the original ligand provided by the literature. These targets are known in the literature to be inhibited by chalcone-derivatives. However, specificity of the particular known chalcone inhibitors to the particular targets is not known. To this end the performance of the generated chalcone library against the list of targets was of interest. The binding energy of ligand-protein complexes was generally good across the library. Statistical analysis including principal component analysis and hierarchical clustering analysis were made in order to investigate for any physical/chemical characteristics which might explain what chalcone features affect the binding energy of the ligand-protein complexes. The spherical polar coordinates defining the orientation of the binding poses were also calculated and used in the statistical analysis. The statistical analysis has allowed us to hypothesize the importance of these radial distances and the polar angles of key atoms in the chalcones in binding to the pyruvate kinase crystal structure. This was validated by the docking of another small library of compound models in which the α,β-unsaturated ketone chain of the chalcone was replaced by incrementally longer conjugated chains. Further studies on the chalcones themselves reveal rotameric systems in both cis and trans-configurations (which may impact binding), and also studied was the effect of Topliss-based modification and its impact of binding to HSP90. Molecular dynamics confirmed good binding of identified chalcone hits.
- Full Text:
- Date Issued: 2020
Adaptations in allopatric populations of Triakis megalopterus isolated by the Benguela Current: steps towards understanding evolutionary processes affecting regional biodiversity
- Authors: Soekoe, Michelle
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5389 , http://hdl.handle.net/10962/d1021264
- Description: This study was initiated to gain a better understanding of evolution and adaptation of elasmobranchs by investigating how a putative biogeographic barrier, the Benguela Current, had influenced populations of a demersal shark species, Triakis megalopterus. It was hypothesized that the Benguela Current formed a biogeographic barrier in the distribution of T. megalopterus and was responsible for the divergence between South African (SA) and Angolan (AN) populations. Since elasmobranchs are generally characterized by a slow rate of evolutionary change and conservative morphology and life history traits, it was hypothesized that there would be limited genetic, morphological and life history divergence between the populations. Both mtDNA Control Region (mtCR) and microsatellites (nDNA) were used to assess population connectivity and structure of T. megalopterus. The mtCR predominantly showed a northern (Angola, AN, and Namibia, NA) versus southern (Western Cape, WC, and Eastern Cape, EC) Benguela subsystem arrangement. This suggested that the formation of the Benguela Current had an influence on the genetic structure of T. megalopterus during the early Pleistocene. The nDNA, however, showed a distinct transoceanic, Atlantic (AN, NA, WC) versus Indian Ocean (EC) arrangement, and this was attributed to the more recent exposure of the Agulhas Bank and reduced rocky shore habitat during the glaciations of the late Pleistocene. Traditional morphological analyses on full body and tooth morphology were used to assess phenotypic plasticity and/or adaptability of T. megalopterus. A novel method of geometric morphology, with potential for non-lethal application, was developed and tested to examine interpopulation divergence in shape. Traditional morphometrics showed significant divergence between populations and this variation was congruous with the mtCR haplotypes. However, the divergence in the truss variables was not concomitant to the haplotypes and suggested that differences in shape may be attributed to phenotypic plasticity. There was limited divergence in the tooth morphology between populations. The divergence in several morphological characters associated with swimming speed and manoeuvrability may be attributed to both habitat structure and dominant prey in the different biogeographic zones. The diet of T. megalopterus consisted primarily of crustaceans, teleosts and molluscs. The significant variation in the diet between populations suggested a generalist tooth configuration and broad trophic adaptability. There was significant divergence in the interpopulation life history parameters. The AN population had the fastest growth, smallest size at maturity, and shortest longevity. Individuals in the EC population had the youngest age at maturity, while the WC population had the earliest parturition. This divergence may be attributed to the contrasting thermal regimes in the three biogeographic regions and the dissimilar exploitation rates of the three populations. The results of this thesis demonstrated that a combination of the formation of the Benguela Current and sea level change most likely contributed to vicariance of three populations of T. megalopterus. The significant interpopulation morphological and life history divergence appeared to be both phenotypic and genetic, and suggested that contrasting environmental drivers can result in relatively rapid change in elasmobranchs.
- Full Text:
- Date Issued: 2016
- Authors: Soekoe, Michelle
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5389 , http://hdl.handle.net/10962/d1021264
- Description: This study was initiated to gain a better understanding of evolution and adaptation of elasmobranchs by investigating how a putative biogeographic barrier, the Benguela Current, had influenced populations of a demersal shark species, Triakis megalopterus. It was hypothesized that the Benguela Current formed a biogeographic barrier in the distribution of T. megalopterus and was responsible for the divergence between South African (SA) and Angolan (AN) populations. Since elasmobranchs are generally characterized by a slow rate of evolutionary change and conservative morphology and life history traits, it was hypothesized that there would be limited genetic, morphological and life history divergence between the populations. Both mtDNA Control Region (mtCR) and microsatellites (nDNA) were used to assess population connectivity and structure of T. megalopterus. The mtCR predominantly showed a northern (Angola, AN, and Namibia, NA) versus southern (Western Cape, WC, and Eastern Cape, EC) Benguela subsystem arrangement. This suggested that the formation of the Benguela Current had an influence on the genetic structure of T. megalopterus during the early Pleistocene. The nDNA, however, showed a distinct transoceanic, Atlantic (AN, NA, WC) versus Indian Ocean (EC) arrangement, and this was attributed to the more recent exposure of the Agulhas Bank and reduced rocky shore habitat during the glaciations of the late Pleistocene. Traditional morphological analyses on full body and tooth morphology were used to assess phenotypic plasticity and/or adaptability of T. megalopterus. A novel method of geometric morphology, with potential for non-lethal application, was developed and tested to examine interpopulation divergence in shape. Traditional morphometrics showed significant divergence between populations and this variation was congruous with the mtCR haplotypes. However, the divergence in the truss variables was not concomitant to the haplotypes and suggested that differences in shape may be attributed to phenotypic plasticity. There was limited divergence in the tooth morphology between populations. The divergence in several morphological characters associated with swimming speed and manoeuvrability may be attributed to both habitat structure and dominant prey in the different biogeographic zones. The diet of T. megalopterus consisted primarily of crustaceans, teleosts and molluscs. The significant variation in the diet between populations suggested a generalist tooth configuration and broad trophic adaptability. There was significant divergence in the interpopulation life history parameters. The AN population had the fastest growth, smallest size at maturity, and shortest longevity. Individuals in the EC population had the youngest age at maturity, while the WC population had the earliest parturition. This divergence may be attributed to the contrasting thermal regimes in the three biogeographic regions and the dissimilar exploitation rates of the three populations. The results of this thesis demonstrated that a combination of the formation of the Benguela Current and sea level change most likely contributed to vicariance of three populations of T. megalopterus. The significant interpopulation morphological and life history divergence appeared to be both phenotypic and genetic, and suggested that contrasting environmental drivers can result in relatively rapid change in elasmobranchs.
- Full Text:
- Date Issued: 2016
Addressing flux suppression, radio frequency interference, and selection of optimal solution intervals during radio interferometric calibration
- Authors: Sob, Ulrich Armel Mbou
- Date: 2020
- Subjects: CubiCal (Software) , Radio -- Interference , Imaging systems in astronomy , Algorithms , Astronomical instruments -- Calibration , Astronomy -- Data processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/147714 , vital:38663
- Description: The forthcoming Square Kilometre Array is expected to provide answers to some of the most intriguing questions about our Universe. However, as it is already noticeable from MeerKAT and other precursors, the amounts of data produced by these new instruments are significantly challenging to calibrate and image. Calibration of radio interferometric data is usually biased by incomplete sky models and radio frequency interference (RFI) resulting in calibration artefacts that limit the dynamic range and image fidelity of the resulting images. One of the most noticeable of these artefacts is the formation of spurious sources which causes suppression of real emissions. Fortunately, it has been shown that calibration algorithms employing heavy-tailed likelihood functions are less susceptible to this due to their robustness against outliers. Leveraging on recent developments in the field of complex optimisation, we implement a robust calibration algorithm using a Student’s t likelihood function and Wirtinger derivatives. The new algorithm, dubbed the robust solver, is incorporated as a subroutine into the newly released calibration software package CubiCal. We perform statistical analysis on the distribution of visibilities and provide an insight into the functioning of the robust solver and describe different scenarios where it will improve calibration. We use simulations to show that the robust solver effectively reduces the amount of flux suppressed from unmodelled sources both in direction independent and direction dependent calibration. Furthermore, the robust solver is shown to successfully mitigate the effects of low-level RFI when applied to a simulated and a real VLA dataset. Finally, we demonstrate that there are close links between the amount of flux suppressed from sources, the effects of the RFI and the employed solution interval during radio interferometric calibration. Hence, we investigate the effects of solution intervals and the different factors to consider in order to select adequate solution intervals. Furthermore, we propose a practical brute force method for selecting optimal solution intervals. The proposed method is successfully applied to a VLA dataset.
- Full Text:
- Date Issued: 2020
- Authors: Sob, Ulrich Armel Mbou
- Date: 2020
- Subjects: CubiCal (Software) , Radio -- Interference , Imaging systems in astronomy , Algorithms , Astronomical instruments -- Calibration , Astronomy -- Data processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/147714 , vital:38663
- Description: The forthcoming Square Kilometre Array is expected to provide answers to some of the most intriguing questions about our Universe. However, as it is already noticeable from MeerKAT and other precursors, the amounts of data produced by these new instruments are significantly challenging to calibrate and image. Calibration of radio interferometric data is usually biased by incomplete sky models and radio frequency interference (RFI) resulting in calibration artefacts that limit the dynamic range and image fidelity of the resulting images. One of the most noticeable of these artefacts is the formation of spurious sources which causes suppression of real emissions. Fortunately, it has been shown that calibration algorithms employing heavy-tailed likelihood functions are less susceptible to this due to their robustness against outliers. Leveraging on recent developments in the field of complex optimisation, we implement a robust calibration algorithm using a Student’s t likelihood function and Wirtinger derivatives. The new algorithm, dubbed the robust solver, is incorporated as a subroutine into the newly released calibration software package CubiCal. We perform statistical analysis on the distribution of visibilities and provide an insight into the functioning of the robust solver and describe different scenarios where it will improve calibration. We use simulations to show that the robust solver effectively reduces the amount of flux suppressed from unmodelled sources both in direction independent and direction dependent calibration. Furthermore, the robust solver is shown to successfully mitigate the effects of low-level RFI when applied to a simulated and a real VLA dataset. Finally, we demonstrate that there are close links between the amount of flux suppressed from sources, the effects of the RFI and the employed solution interval during radio interferometric calibration. Hence, we investigate the effects of solution intervals and the different factors to consider in order to select adequate solution intervals. Furthermore, we propose a practical brute force method for selecting optimal solution intervals. The proposed method is successfully applied to a VLA dataset.
- Full Text:
- Date Issued: 2020
Adherence to antiretroviral therapy in children in Zimbabwe: a randomized control trial to validate a new self-reported adherence monitoring tool
- Authors: Mugore, Linnetie
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54734 , vital:26607
- Description: Background: Among children taking antiretroviral therapy (ART), self-reports have been widely reported to over-estimate adherence levels. Pill count adherence levels are often lower than self-reported levels, with unannounced home pill count adherence being lower than facility based pill count adherence. There is often poor agreement between pill count adherence levels and those measured using other objective adherence measuring methods such as Medication Event Monitoring Systems (MEMS®), which is widely viewed as the gold standard for adherence measurement. Objectives: The aim of this study was to design and evaluate a new self-reported paediatric adherence monitoring tool, assess the feasibility of using pill count methods in monitoring adherence and identify challenges to reporting adherence among children on ART in rural and urban Zimbabwe. Methods A dual centre, superiority, parallel design RCT was conducted to evaluate the newly-developed visually- and verbally-cued „past 10 days‟ tool for the assessment of adherence in children on ART at two sites in Zimbabwe; Harare Central Children‟s Hospital in an urban setting, and Murambinda Mission Hospital, a rural site. Child-caregiver pairs presenting to one of these facilities for the child‟s review of ART and refill of the medication were recruited, signed informed consent obtained, and were randomised for self-reported adherence monitoring into either the experimental group („new 10-day tool‟) or the control group („PACTG-style‟ self-report tool). Data (demographic, socioeconomic, and reported adherence) were collected in individual interviews with child-caregiver pairs. Additional adherence monitoring methods used for both groups included the Morisky-8-Item Medication Adherence Scale (MMAS-8) and a facility based pill count. FGDs were held with groups of caregivers and groups of children ≥13 years of age to understand reasons for non-adherence as well as issues around reporting non-adherence. Superiority testing was conducted by comparing adherent proportions and their confidence intervals (95% CI). Further concurrent validity test was done using the Mann-Whitney U test to evaluate the relationship between the new tool and the MMAS-8 scores. Agreement between the child and caregiver reports of adherence was used as a test of reliability of the new tool using the kappa statistic. Socio-demographic, clinical and care-related factors associated with adherence were identified using reported adherence in both child and caregiver groups in a logistic regression model. Two pill count methods were assessed for feasibility using the proportions of children with complete data for calculating adherence levels, and their CI and a comparison of the two methods, a routinely-used method and one that incorporated the reported residual quantity (RRQ) of medication at last refill. Results : Analysis included 245 child-caregiver pairs, 123 in the experimental group and 122 in the control group. The median age for children was 9 years. In the experimental group, adherence by caregiver and child reports ranged from 94.3% - 98.4% and 78.4% - 96.1%, and those in the control group ranged from 89.2% - 97.5% and 71.2% - 98.1%, respectively. There was no significant difference between adherence levels in the two groups. Adherence levels measured by both the experimental and control tools were found to be associated with MMAS-8 adherence levels (p <0.05). Agreement between child- and caregiver-reported adherence was moderate though significant (kappa; 0.407, p <0.05). Only about half of the children had adequate data to compute pill counts. Proportions adherent at 95% cut-off were 39% by the „routine pill count‟ and 58% by the „Pill count RRQ‟. Being an orphan was associated with child reported-adherence whereas use of non-human reminders, having a maternal relative as a primary caregiver and knowledge of dose frequency, were all associated with caregiver-reported adherence. Major causes of non-adherence mentioned during the FGDs included interference of medication administration times with scheduling of routine socio-economic activities and lack of support from some non-biological caregivers. Reporting of non-adherence appeared to be hampered by perceptions of negative reactions by healthcare workers to these reports and by caregivers being unaware that the child missed some doses. Conclusions: The „new 10-day tool‟ was not shown to be superior to the „PACTG-style tool‟ in detecting non-adherence, however this new tool was found to be a valid and reliable adherence monitoring tool that included a moderately long recall period of 10 days, can be applied without the need for the respondent to remember names of individual medicines in the
- Full Text:
- Date Issued: 2014
- Authors: Mugore, Linnetie
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54734 , vital:26607
- Description: Background: Among children taking antiretroviral therapy (ART), self-reports have been widely reported to over-estimate adherence levels. Pill count adherence levels are often lower than self-reported levels, with unannounced home pill count adherence being lower than facility based pill count adherence. There is often poor agreement between pill count adherence levels and those measured using other objective adherence measuring methods such as Medication Event Monitoring Systems (MEMS®), which is widely viewed as the gold standard for adherence measurement. Objectives: The aim of this study was to design and evaluate a new self-reported paediatric adherence monitoring tool, assess the feasibility of using pill count methods in monitoring adherence and identify challenges to reporting adherence among children on ART in rural and urban Zimbabwe. Methods A dual centre, superiority, parallel design RCT was conducted to evaluate the newly-developed visually- and verbally-cued „past 10 days‟ tool for the assessment of adherence in children on ART at two sites in Zimbabwe; Harare Central Children‟s Hospital in an urban setting, and Murambinda Mission Hospital, a rural site. Child-caregiver pairs presenting to one of these facilities for the child‟s review of ART and refill of the medication were recruited, signed informed consent obtained, and were randomised for self-reported adherence monitoring into either the experimental group („new 10-day tool‟) or the control group („PACTG-style‟ self-report tool). Data (demographic, socioeconomic, and reported adherence) were collected in individual interviews with child-caregiver pairs. Additional adherence monitoring methods used for both groups included the Morisky-8-Item Medication Adherence Scale (MMAS-8) and a facility based pill count. FGDs were held with groups of caregivers and groups of children ≥13 years of age to understand reasons for non-adherence as well as issues around reporting non-adherence. Superiority testing was conducted by comparing adherent proportions and their confidence intervals (95% CI). Further concurrent validity test was done using the Mann-Whitney U test to evaluate the relationship between the new tool and the MMAS-8 scores. Agreement between the child and caregiver reports of adherence was used as a test of reliability of the new tool using the kappa statistic. Socio-demographic, clinical and care-related factors associated with adherence were identified using reported adherence in both child and caregiver groups in a logistic regression model. Two pill count methods were assessed for feasibility using the proportions of children with complete data for calculating adherence levels, and their CI and a comparison of the two methods, a routinely-used method and one that incorporated the reported residual quantity (RRQ) of medication at last refill. Results : Analysis included 245 child-caregiver pairs, 123 in the experimental group and 122 in the control group. The median age for children was 9 years. In the experimental group, adherence by caregiver and child reports ranged from 94.3% - 98.4% and 78.4% - 96.1%, and those in the control group ranged from 89.2% - 97.5% and 71.2% - 98.1%, respectively. There was no significant difference between adherence levels in the two groups. Adherence levels measured by both the experimental and control tools were found to be associated with MMAS-8 adherence levels (p <0.05). Agreement between child- and caregiver-reported adherence was moderate though significant (kappa; 0.407, p <0.05). Only about half of the children had adequate data to compute pill counts. Proportions adherent at 95% cut-off were 39% by the „routine pill count‟ and 58% by the „Pill count RRQ‟. Being an orphan was associated with child reported-adherence whereas use of non-human reminders, having a maternal relative as a primary caregiver and knowledge of dose frequency, were all associated with caregiver-reported adherence. Major causes of non-adherence mentioned during the FGDs included interference of medication administration times with scheduling of routine socio-economic activities and lack of support from some non-biological caregivers. Reporting of non-adherence appeared to be hampered by perceptions of negative reactions by healthcare workers to these reports and by caregivers being unaware that the child missed some doses. Conclusions: The „new 10-day tool‟ was not shown to be superior to the „PACTG-style tool‟ in detecting non-adherence, however this new tool was found to be a valid and reliable adherence monitoring tool that included a moderately long recall period of 10 days, can be applied without the need for the respondent to remember names of individual medicines in the
- Full Text:
- Date Issued: 2014
Advanced ionospheric chirpsounding
- Authors: Poole, Allon William Victor
- Date: 1984
- Subjects: Ionospheric sounds Ionosphere -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5446 , http://hdl.handle.net/10962/d1001999
- Description: This dissertation reports research into the theory and practical application of linear frequency modulated ionospheric sounding, as an alternative to the more usual technique of pulse modulation. A comparison of this technique with that of conventional pulse sounders is given, based on the concepts of matched filters and ambiguity functions for both modulations. A theory is developed to relate the group range and phase velocity of the ionospheric target to the phase and frequency of the difference signal at the receiver output. A method is then described whereby the group range and phase velocity of the reflection point as well as the amplitude, arrival angle and polarisation mode of the reflected energy can be measured. A description of the implementation of the technique is given together with some initial results. Finally, some suggestions for improvements are given
- Full Text:
- Date Issued: 1984
- Authors: Poole, Allon William Victor
- Date: 1984
- Subjects: Ionospheric sounds Ionosphere -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5446 , http://hdl.handle.net/10962/d1001999
- Description: This dissertation reports research into the theory and practical application of linear frequency modulated ionospheric sounding, as an alternative to the more usual technique of pulse modulation. A comparison of this technique with that of conventional pulse sounders is given, based on the concepts of matched filters and ambiguity functions for both modulations. A theory is developed to relate the group range and phase velocity of the ionospheric target to the phase and frequency of the difference signal at the receiver output. A method is then described whereby the group range and phase velocity of the reflection point as well as the amplitude, arrival angle and polarisation mode of the reflected energy can be measured. A description of the implementation of the technique is given together with some initial results. Finally, some suggestions for improvements are given
- Full Text:
- Date Issued: 1984
Advanced radio interferometric simulation and data reduction techniques
- Authors: Makhathini, Sphesihle
- Date: 2018
- Subjects: Interferometry , Radio interferometers , Algorithms , Radio telescopes , Square Kilometre Array (Project) , Very Large Array (Observatory : N.M.) , Radio astronomy
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/57348 , vital:26875
- Description: This work shows how legacy and novel radio Interferometry software packages and algorithms can be combined to produce high-quality reductions from modern telescopes, as well as end-to-end simulations for upcoming instruments such as the Square Kilometre Array (SKA) and its pathfinders. We first use a MeqTrees based simulations framework to quantify how artefacts due to direction-dependent effects accumulate with time, and the consequences of this accumulation when observing the same field multiple times in order to reach the survey depth. Our simulations suggest that a survey like LADUMA (Looking at the Distant Universe with MeerKAT Array), which aims to achieve its survey depth of 16 µJy/beam in a 72 kHz at 1.42 GHz by observing the same field for 1000 hours, will be able to reach its target depth in the presence of these artefacts. We also present stimela, a system agnostic scripting framework for simulating, processing and imaging radio interferometric data. This framework is then used to write an end-to-end simulation pipeline in order to quantify the resolution and sensitivity of the SKA1-MID telescope (the first phase of the SKA mid-frequency telescope) as a function of frequency, as well as the scale-dependent sensitivity of the telescope. Finally, a stimela-based reduction pipeline is used to process data of the field around the source 3C147, taken by the Karl G. Jansky Very Large Array (VLA). The reconstructed image from this reduction has a typical 1a noise level of 2.87 µJy/beam, and consequently a dynamic range of 8x106:1, given the 22.58 Jy/beam flux Density of the source 3C147.
- Full Text:
- Date Issued: 2018
- Authors: Makhathini, Sphesihle
- Date: 2018
- Subjects: Interferometry , Radio interferometers , Algorithms , Radio telescopes , Square Kilometre Array (Project) , Very Large Array (Observatory : N.M.) , Radio astronomy
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/57348 , vital:26875
- Description: This work shows how legacy and novel radio Interferometry software packages and algorithms can be combined to produce high-quality reductions from modern telescopes, as well as end-to-end simulations for upcoming instruments such as the Square Kilometre Array (SKA) and its pathfinders. We first use a MeqTrees based simulations framework to quantify how artefacts due to direction-dependent effects accumulate with time, and the consequences of this accumulation when observing the same field multiple times in order to reach the survey depth. Our simulations suggest that a survey like LADUMA (Looking at the Distant Universe with MeerKAT Array), which aims to achieve its survey depth of 16 µJy/beam in a 72 kHz at 1.42 GHz by observing the same field for 1000 hours, will be able to reach its target depth in the presence of these artefacts. We also present stimela, a system agnostic scripting framework for simulating, processing and imaging radio interferometric data. This framework is then used to write an end-to-end simulation pipeline in order to quantify the resolution and sensitivity of the SKA1-MID telescope (the first phase of the SKA mid-frequency telescope) as a function of frequency, as well as the scale-dependent sensitivity of the telescope. Finally, a stimela-based reduction pipeline is used to process data of the field around the source 3C147, taken by the Karl G. Jansky Very Large Array (VLA). The reconstructed image from this reduction has a typical 1a noise level of 2.87 µJy/beam, and consequently a dynamic range of 8x106:1, given the 22.58 Jy/beam flux Density of the source 3C147.
- Full Text:
- Date Issued: 2018
African mead biotechnology and indigenous knowledge systems in iQhilika process development
- Authors: Cambray, Garth Anton
- Date: 2005
- Subjects: Biotechnology Indigenous peoples -- Africa Ethnoscience -- Africa Mead -- Africa Brewing -- Microbiology Honeybee Honey
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3929 , http://hdl.handle.net/10962/d1003988
- Description: While the production of mead, a fermented honey beverage, has declined in popularity around the world in recent centuries, a substantial mead industry continues to exist in Africa with an estimated annual production of 1 to 1.7 billion litres. This is largely an ‘invisible industry’, and has functioned outside the formal economy due to proscription of indigenous beverages during colonial times. The traditional African mead industry is, however, also now under pressure due to the environmental degradation of scarce natural ingredients, urbanisation and loss of indigenous knowledge systems (IKS) and, with time, the beverage will likely follow the declining trend of mead consumption observed elsewhere. An analysis of early reports of African mead production suggested that the Khoi-San, among the earliest inhabitants of the continent, are the originators of the mead making techniques which use fibrous plant materials derived from specific plant species, to facilitate mead fermentation in some way. The Eastern Cape represents a region with a large body of Khoi-San IKS preserved in their descendants among the Afrikaans and Xhosa populations. A survey to establish a baseline of mead-making technology in the Eastern Cape was undertaken, and involved interviewing traditional mead makers across an area of roughly 100 000 km2, showing that the mead, iQhilika(Xhosa) Kari (Khoi-San/Afrikaans), is produced using a very similar process throughout the region. This involves the roots of a Trichodiadema sp. plant (imoela – Xhosa, karimoer – Afrikaans/Khoi-San), honey, extract of brood and/or pollen and water. Various other fruit sugar sources were also found to be added at times producing seasonal beverages with unique organoleptic properties. A model traditional iQhilika production operation was investigated in order to describe the main features of the process. Biomass immobilised on Trichodiadema root segments was found to be distributed evenly through the profile of the bioreactor resulting in a well mixed fermentation and a productivity of 0.74 g EtOH/l/h. In the initial stages of fermentation, the ethanol yield was highest in the mid-regions of the bioreactor, but with time the regions closer to the surface, which had atmospheric contact had a higher yield. This phenomenon was attributed to aerobic fatty acid synthesis which allowed the yeast close to the surface to function more efficiently despite rising ethanol concentrations. The mead contained 44.25 g/l (7 % volume) ethanol produced in a fermentation time of 43.5 h. Yeast biomass in the traditional process was either immobilised in the form of flocs or attached to the Trichodiadema intonsum support. Electron microscopy revealed that the cells were covered in a layer of extra-cellular polymeric substance apparently assisting the immobilization, and which was populated by a consortium of yeasts and bacteria. Yeasts isolated from iQhilika brewed in two regions separated by 350 km were found to be very closely related Saccharomyces cerevisiae strains as determined by molecular genetic analysis. The traditional beverage was found to contain populations of Lactic acid bacteria (LAB), which are known spoilage organisms in other beverages. Spoilage characteristics of these organisms matched descriptions of spoilage provided by the IKS survey. Other possibly beneficial LAB, which may contribute useful flavour compounds, were also found to be present in the system. The basic functional aspects of the traditional process were used to design a continuous bench-scale tower bioreactor and process development was based on the IKS survey. This consisted of a packed bed bioreactor, consisting of 2 mm3 T. intonsum root segments, immobilising a novel Saccharomyces cerevisiae strain isolated from a traditional batch of iQhilika. The bioreactor performed well with a yield of close to the theoretical maximum and an ethanol productivity of 3.45 g EtOH/l/h. The parameters of the 5.6 l/d bench-scale bioreactor were used to design a full-scale production bioreactor with a planned maximum output of 330 l/d. This bioreactor had a productivity of 0.19 g EtOH/l/h. The organoleptic properties of the product produced were considered by a taste panel to be better than those of the product of the bench-scale tower bioreactor. This research was based on the development of IKS which imposed a number of constraints and obligations on the project to ensure environmental, and social, in addition to financial viability of the scale-up operation. Makana Meadery was established in partnership with Rhodes University as an empowerment company which, in addition to undertaking the commercialisation of the iQhilika process, would also develop methods for the production of scarce ingredients traditionally unsustainably sourced from fragile ecosystems, provide beekeeping training and the manufacture of beehives.
- Full Text:
- Date Issued: 2005
- Authors: Cambray, Garth Anton
- Date: 2005
- Subjects: Biotechnology Indigenous peoples -- Africa Ethnoscience -- Africa Mead -- Africa Brewing -- Microbiology Honeybee Honey
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3929 , http://hdl.handle.net/10962/d1003988
- Description: While the production of mead, a fermented honey beverage, has declined in popularity around the world in recent centuries, a substantial mead industry continues to exist in Africa with an estimated annual production of 1 to 1.7 billion litres. This is largely an ‘invisible industry’, and has functioned outside the formal economy due to proscription of indigenous beverages during colonial times. The traditional African mead industry is, however, also now under pressure due to the environmental degradation of scarce natural ingredients, urbanisation and loss of indigenous knowledge systems (IKS) and, with time, the beverage will likely follow the declining trend of mead consumption observed elsewhere. An analysis of early reports of African mead production suggested that the Khoi-San, among the earliest inhabitants of the continent, are the originators of the mead making techniques which use fibrous plant materials derived from specific plant species, to facilitate mead fermentation in some way. The Eastern Cape represents a region with a large body of Khoi-San IKS preserved in their descendants among the Afrikaans and Xhosa populations. A survey to establish a baseline of mead-making technology in the Eastern Cape was undertaken, and involved interviewing traditional mead makers across an area of roughly 100 000 km2, showing that the mead, iQhilika(Xhosa) Kari (Khoi-San/Afrikaans), is produced using a very similar process throughout the region. This involves the roots of a Trichodiadema sp. plant (imoela – Xhosa, karimoer – Afrikaans/Khoi-San), honey, extract of brood and/or pollen and water. Various other fruit sugar sources were also found to be added at times producing seasonal beverages with unique organoleptic properties. A model traditional iQhilika production operation was investigated in order to describe the main features of the process. Biomass immobilised on Trichodiadema root segments was found to be distributed evenly through the profile of the bioreactor resulting in a well mixed fermentation and a productivity of 0.74 g EtOH/l/h. In the initial stages of fermentation, the ethanol yield was highest in the mid-regions of the bioreactor, but with time the regions closer to the surface, which had atmospheric contact had a higher yield. This phenomenon was attributed to aerobic fatty acid synthesis which allowed the yeast close to the surface to function more efficiently despite rising ethanol concentrations. The mead contained 44.25 g/l (7 % volume) ethanol produced in a fermentation time of 43.5 h. Yeast biomass in the traditional process was either immobilised in the form of flocs or attached to the Trichodiadema intonsum support. Electron microscopy revealed that the cells were covered in a layer of extra-cellular polymeric substance apparently assisting the immobilization, and which was populated by a consortium of yeasts and bacteria. Yeasts isolated from iQhilika brewed in two regions separated by 350 km were found to be very closely related Saccharomyces cerevisiae strains as determined by molecular genetic analysis. The traditional beverage was found to contain populations of Lactic acid bacteria (LAB), which are known spoilage organisms in other beverages. Spoilage characteristics of these organisms matched descriptions of spoilage provided by the IKS survey. Other possibly beneficial LAB, which may contribute useful flavour compounds, were also found to be present in the system. The basic functional aspects of the traditional process were used to design a continuous bench-scale tower bioreactor and process development was based on the IKS survey. This consisted of a packed bed bioreactor, consisting of 2 mm3 T. intonsum root segments, immobilising a novel Saccharomyces cerevisiae strain isolated from a traditional batch of iQhilika. The bioreactor performed well with a yield of close to the theoretical maximum and an ethanol productivity of 3.45 g EtOH/l/h. The parameters of the 5.6 l/d bench-scale bioreactor were used to design a full-scale production bioreactor with a planned maximum output of 330 l/d. This bioreactor had a productivity of 0.19 g EtOH/l/h. The organoleptic properties of the product produced were considered by a taste panel to be better than those of the product of the bench-scale tower bioreactor. This research was based on the development of IKS which imposed a number of constraints and obligations on the project to ensure environmental, and social, in addition to financial viability of the scale-up operation. Makana Meadery was established in partnership with Rhodes University as an empowerment company which, in addition to undertaking the commercialisation of the iQhilika process, would also develop methods for the production of scarce ingredients traditionally unsustainably sourced from fragile ecosystems, provide beekeeping training and the manufacture of beehives.
- Full Text:
- Date Issued: 2005
African traditional medicine-antiretroviral interactions : effects of Sutherlandia frutescens on the pharmacokinetics of Atazanavir
- Authors: Müller, Adrienne Carmel
- Date: 2011 , 2011-03-28
- Subjects: Antiretroviral agents , Medicinal plants , Traditional medicine , AIDS (Disease) -- Treatment , HIV infections -- Drug therapy , Drug interactions , Pharmacokinetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3859 , http://hdl.handle.net/10962/d1013373
- Description: In response to the urgent call for investigations into antiretroviral (ARV)-African traditional medicine (ATM) interactions, this research was undertaken to ascertain whether chronic administration of the ATM, Sutherlandia frutescens (SF) may alter the bioavailability of the protease inhibitor (PI), atazanavir (ATV), which may impact on the safety or efficacy of the ARV. Prior to investigating a potential interaction between ATV and SF in vitro and in vivo, a high performance liquid chromatography method with ultraviolet detection (HPLC-UV) was developed and validated for the bioanalysis of ATV in human plasma and liver microsomes. An improved and efficient analytical method with minimal use of solvents and short run time was achieved in comparison to methods published in the literature. In addition, the method was selective, linear, accurate and precise for quantitative analysis of ATV in these studies. Molecular docking studies were conducted to compare the binding modes and affinities of ATV and two major SF constituents, Sutherlandioside B and Sutherlandin C, with the efflux transporter, P-glycoprotein (P-gp) and the CYP450 isoenzyme, CYP3A4 to determine the potential for these phytochemicals to competitively inhibit the binding of ATV to these two proteins, which are mediators of absorption and metabolism. These studies revealed that modulation of P-gp transport of ATV by Sutherlandioside B and Sutherlandin C was not likely to occur via competitive inhibition. The results further indicated that weak competitive inhibition of CYP3A4 may possibly occur in the presence of either of these two SF constituents. The Caco-2 cell line was used as an in vitro model of human intestinal absorption. Accumulation studies in these cells were conducted to ascertain whether extracts and constituents of SF have the ability to alter the absorption of ATV. The results showed that the aqueous extract of SF significantly reduced ATV accumulation, suggesting decreased ATV absorption, whilst a triterpenoid glycoside fraction isolated from SF exhibited an opposing effect. Analogous responses were elicited by the aqueous extract and a triterpenoid glycoside fraction in similar accumulation studies in P-gp overexpressing Madin–Darby Canine Kidney Strain II cells (MDCKII-MDR1), which signified that the effects of this extract and component on ATV transport in the Caco-2 cells were P-gp-mediated. The quantitative analysis of ATV in human liver microsomes after co-incubation with extracts and components of SF was conducted to determine the effects of SF on the metabolism of ATV. The aqueous and methanolic extracts of SF inhibited ATV metabolism, whilst the triterpenoid glycoside fraction had a converse effect. Analogous effects by the extracts were demonstrated in experiments conducted in CYP3A4-transfected microsomes, suggesting that the inhibition of ATV metabolism in the liver microsomes by these SF extracts was CYP3A4-mediated. A combination of Sutherlandiosides C and D also inhibited CYP3A4-mediated ATV metabolism, which was in contrast to the response elicited by the triterpenoid fraction in the liver microsomes, where other unidentified compounds, shown to be present therein, may have contributed to the activation of ATV metabolism. The in vitro studies revealed the potential for SF to alter the bioavailability of ATV, therefore a clinical study in which the effect of a multiple dose regimen of SF on the pharmacokinetics (PK) of a single dose of ATV was conducted in healthy male volunteers. The statistical analysis showed that the 90 % confidence intervals around the geometric mean ratios (ATV + SF/ATV alone) for both Cmax and AUC0-24 hours, fell well below the lower limit of the "no-effect" boundary of 0.8 – 1.25, implying that the bioavailability of ATV was significantly reduced in this cohort of subjects. It may thus be concluded that if the reduction in bioavailability observed in this clinical study is found to be clinically relevant, co-administration of SF commercial dosage forms and ATV in HIV/AIDS patients may potentially result in subtherapeutic ATV levels, which may in turn contribute to ATV resistance and/or treatment failure. This research has therefore highlighted the potential risk for toxicity or lack of efficacy of ARV regimens which may result when ATMs and PIs are used concurrently and that patients and health care practitioners alike should be aware of these perils.
- Full Text:
- Date Issued: 2011
- Authors: Müller, Adrienne Carmel
- Date: 2011 , 2011-03-28
- Subjects: Antiretroviral agents , Medicinal plants , Traditional medicine , AIDS (Disease) -- Treatment , HIV infections -- Drug therapy , Drug interactions , Pharmacokinetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3859 , http://hdl.handle.net/10962/d1013373
- Description: In response to the urgent call for investigations into antiretroviral (ARV)-African traditional medicine (ATM) interactions, this research was undertaken to ascertain whether chronic administration of the ATM, Sutherlandia frutescens (SF) may alter the bioavailability of the protease inhibitor (PI), atazanavir (ATV), which may impact on the safety or efficacy of the ARV. Prior to investigating a potential interaction between ATV and SF in vitro and in vivo, a high performance liquid chromatography method with ultraviolet detection (HPLC-UV) was developed and validated for the bioanalysis of ATV in human plasma and liver microsomes. An improved and efficient analytical method with minimal use of solvents and short run time was achieved in comparison to methods published in the literature. In addition, the method was selective, linear, accurate and precise for quantitative analysis of ATV in these studies. Molecular docking studies were conducted to compare the binding modes and affinities of ATV and two major SF constituents, Sutherlandioside B and Sutherlandin C, with the efflux transporter, P-glycoprotein (P-gp) and the CYP450 isoenzyme, CYP3A4 to determine the potential for these phytochemicals to competitively inhibit the binding of ATV to these two proteins, which are mediators of absorption and metabolism. These studies revealed that modulation of P-gp transport of ATV by Sutherlandioside B and Sutherlandin C was not likely to occur via competitive inhibition. The results further indicated that weak competitive inhibition of CYP3A4 may possibly occur in the presence of either of these two SF constituents. The Caco-2 cell line was used as an in vitro model of human intestinal absorption. Accumulation studies in these cells were conducted to ascertain whether extracts and constituents of SF have the ability to alter the absorption of ATV. The results showed that the aqueous extract of SF significantly reduced ATV accumulation, suggesting decreased ATV absorption, whilst a triterpenoid glycoside fraction isolated from SF exhibited an opposing effect. Analogous responses were elicited by the aqueous extract and a triterpenoid glycoside fraction in similar accumulation studies in P-gp overexpressing Madin–Darby Canine Kidney Strain II cells (MDCKII-MDR1), which signified that the effects of this extract and component on ATV transport in the Caco-2 cells were P-gp-mediated. The quantitative analysis of ATV in human liver microsomes after co-incubation with extracts and components of SF was conducted to determine the effects of SF on the metabolism of ATV. The aqueous and methanolic extracts of SF inhibited ATV metabolism, whilst the triterpenoid glycoside fraction had a converse effect. Analogous effects by the extracts were demonstrated in experiments conducted in CYP3A4-transfected microsomes, suggesting that the inhibition of ATV metabolism in the liver microsomes by these SF extracts was CYP3A4-mediated. A combination of Sutherlandiosides C and D also inhibited CYP3A4-mediated ATV metabolism, which was in contrast to the response elicited by the triterpenoid fraction in the liver microsomes, where other unidentified compounds, shown to be present therein, may have contributed to the activation of ATV metabolism. The in vitro studies revealed the potential for SF to alter the bioavailability of ATV, therefore a clinical study in which the effect of a multiple dose regimen of SF on the pharmacokinetics (PK) of a single dose of ATV was conducted in healthy male volunteers. The statistical analysis showed that the 90 % confidence intervals around the geometric mean ratios (ATV + SF/ATV alone) for both Cmax and AUC0-24 hours, fell well below the lower limit of the "no-effect" boundary of 0.8 – 1.25, implying that the bioavailability of ATV was significantly reduced in this cohort of subjects. It may thus be concluded that if the reduction in bioavailability observed in this clinical study is found to be clinically relevant, co-administration of SF commercial dosage forms and ATV in HIV/AIDS patients may potentially result in subtherapeutic ATV levels, which may in turn contribute to ATV resistance and/or treatment failure. This research has therefore highlighted the potential risk for toxicity or lack of efficacy of ARV regimens which may result when ATMs and PIs are used concurrently and that patients and health care practitioners alike should be aware of these perils.
- Full Text:
- Date Issued: 2011
Afro-communitarianism and the nature of reconciliation
- Authors: Oelofsen, Rianna
- Date: 2013
- Subjects: Ubuntu (Philosophy) Reconciliation -- South Africa Communitarianism -- Africa Philosophy, African
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2736 , http://hdl.handle.net/10962/d1006809
- Description: In this dissertation I sketch a conception of personhood as understood from within an Afrocommunitarian worldview, and argue that this understanding of personhood has implications for understanding the concept of reconciliation. Understanding ‘being human’ as a collective, communal enterprise has implications for how responsibility, justice, forgiveness and humanization (all cognate concepts of reconciliation) are conceptualized. In line with this understanding of reconciliation and its cognate concepts, I argue that the humanization of self and other (according to the Afrocommunitarian understanding of personhood) is required for addressing the ‘inferiority’ and concurrent ‘superiority’ racial complexes as diagnosed by Franz Fanon and Steve Biko. These complexes reach deeply within individual and collective psyches and political identities, and I argue that political solutions to protracted conflict (in South Africa and other racially charged contexts) which do not address these deeply entrenched pathologies will be inadequate according to an Afrocommunitarian framework.
- Full Text:
- Date Issued: 2013
- Authors: Oelofsen, Rianna
- Date: 2013
- Subjects: Ubuntu (Philosophy) Reconciliation -- South Africa Communitarianism -- Africa Philosophy, African
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2736 , http://hdl.handle.net/10962/d1006809
- Description: In this dissertation I sketch a conception of personhood as understood from within an Afrocommunitarian worldview, and argue that this understanding of personhood has implications for understanding the concept of reconciliation. Understanding ‘being human’ as a collective, communal enterprise has implications for how responsibility, justice, forgiveness and humanization (all cognate concepts of reconciliation) are conceptualized. In line with this understanding of reconciliation and its cognate concepts, I argue that the humanization of self and other (according to the Afrocommunitarian understanding of personhood) is required for addressing the ‘inferiority’ and concurrent ‘superiority’ racial complexes as diagnosed by Franz Fanon and Steve Biko. These complexes reach deeply within individual and collective psyches and political identities, and I argue that political solutions to protracted conflict (in South Africa and other racially charged contexts) which do not address these deeply entrenched pathologies will be inadequate according to an Afrocommunitarian framework.
- Full Text:
- Date Issued: 2013
Agnation, alternative structures, and the individual in Chopi society
- Authors: Webster, D J
- Date: 1976
- Subjects: Chopi (African people) , Ethnology -- Mozambique
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2122 , http://hdl.handle.net/10962/d1013288
- Full Text:
- Date Issued: 1976
- Authors: Webster, D J
- Date: 1976
- Subjects: Chopi (African people) , Ethnology -- Mozambique
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2122 , http://hdl.handle.net/10962/d1013288
- Full Text:
- Date Issued: 1976
Aiding the education agenda? the role of non-governmental organisations in learner performance and retention in Joza, Grahamstown, South Africa
- Authors: Nomsenge, Sinazo Onela
- Date: 2019
- Subjects: Non-governmental organizations , Non-governmental organizations -- South Africa -- Makhanda , Black people -- Education -- South Africa -- Makhanda , Education -- South Africa -- Makhanda , Joza Youth Hub (Makhanda) , Upstart Youth Development Project (Makhanda) , Village Scribe Association (Makhanda) , Ikamba Youth (Makhanda) , Access Music Project(Makhanda)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76468 , vital:30568
- Description: This thesis describes the network of complexities that characterise the world and work of Non-Governmental Organisations (NGOs). It examines the ways in which organisations navigate different internal, sectoral and contextual intricacies while operating under the command of their chosen developmental mandates. This description is drawn from a sociological analysis of the internal workings of education NGOs, their external affiliations as well as the negotiations which underpin their operations and survival. Collectively, the careful illustration of these underpinnings outlines both the role that NGOs play in the performance and retention of learners in the Grahamstown-east township of Joza and also their position in the town’s basic education sector. Private and non-governmental interveners have, particularly from the closing decades of the 20th century, been conceptually and operationally deployed as panaceas of the socio-economic scarcities which continue to pervade much of the ‘developing’ world. Their involvement in the socio-economic missions of populations living in the Global South has grown both laterally and in the depth of how development is understood and defined, carried out and also measured. NGOs, as widely acclaimed institutional arms of global development imperatives, therefore assume prominent positions in framing policy and implementation models, prescribing performance benchmarks and pronouncing non-compliance. Likewise, education NGOs have obtained normative prescription status in global education policy and practice largely on the back of the Education for All (EFA) objectives, the Millennium Development Goals (MDGs) and the neo-liberal logics which have championed state retreat in favour of private sector ascendance in globalised development. This, in conjunction with the persistent struggles of educational transformation in the Global South, has given NGOs little trouble in legitimising their prominent presence in education and other sectors of socio-economic relief in these parts of the world. Little illusion remains however, in many commentary circles, of the role of NGOs in advancing development ideals, the honesty of their altruistic intents, their ideological leanings as well as their efficacy in carrying out their mandates. As such, the logics which have been used to dethrone developing state structures in order to expand the space for private intervention along with the prevailing and deepening markers of educational underperformance, have been central features of the criticisms levelled against NGOs. This thesis intervenes in these ongoing reflections by describing the role of NGOs in educational outcomes, particularly learner performance and retention in Joza. This analysis demonstrates the organisational, sector-level and broader community forces which influence not only the form which non-state interventions take on and the daily preoccupations of their carriers but broadly, the position they occupy in the town’s overall educational profile. By way of locating NGOs within Grahamstown’s educational landscape, this thesis first demonstrates, the conflicted nature of NGO operations from an international, sectoral, national, local and organisational level. The discussion then illustrates how the preoccupations of NGOs are scattered between the different communities which they occupy within these levels. Their reliance on these players demands that organisations be tactical in guarding both their survival and, at times, the conflicting allegiances which grant them different forms of legitimacy. Internal struggles which characterise this imbalance of forces results in a trade-off which often favours organisational preservation mechanisms over systemic educational overhaul. As such, while non-state interveners can be lauded for extending educational support to those who would otherwise not have such, the gains of NGO intervention are often absorbed by internal urgencies for organisational legitimacy and preservation. This, in a context which possesses a unique set of socio-economic and educational deficits that require, at the very least, radical and unbridled mediation, means that pre-existing inequalities in educational inputs and outcomes along with the resultant inequities in youth socio-economic prospects, can find refuge in the very sector whose support and intervention is sought out and justified for such. This thesis lays out the nuances of these tensions and contradictions and offers this case as a point of reference for further considerations of the persistent markers of underperformance which characterise developing communities that enjoy high concentrations of non-state educational intervention.
- Full Text:
- Date Issued: 2019
- Authors: Nomsenge, Sinazo Onela
- Date: 2019
- Subjects: Non-governmental organizations , Non-governmental organizations -- South Africa -- Makhanda , Black people -- Education -- South Africa -- Makhanda , Education -- South Africa -- Makhanda , Joza Youth Hub (Makhanda) , Upstart Youth Development Project (Makhanda) , Village Scribe Association (Makhanda) , Ikamba Youth (Makhanda) , Access Music Project(Makhanda)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76468 , vital:30568
- Description: This thesis describes the network of complexities that characterise the world and work of Non-Governmental Organisations (NGOs). It examines the ways in which organisations navigate different internal, sectoral and contextual intricacies while operating under the command of their chosen developmental mandates. This description is drawn from a sociological analysis of the internal workings of education NGOs, their external affiliations as well as the negotiations which underpin their operations and survival. Collectively, the careful illustration of these underpinnings outlines both the role that NGOs play in the performance and retention of learners in the Grahamstown-east township of Joza and also their position in the town’s basic education sector. Private and non-governmental interveners have, particularly from the closing decades of the 20th century, been conceptually and operationally deployed as panaceas of the socio-economic scarcities which continue to pervade much of the ‘developing’ world. Their involvement in the socio-economic missions of populations living in the Global South has grown both laterally and in the depth of how development is understood and defined, carried out and also measured. NGOs, as widely acclaimed institutional arms of global development imperatives, therefore assume prominent positions in framing policy and implementation models, prescribing performance benchmarks and pronouncing non-compliance. Likewise, education NGOs have obtained normative prescription status in global education policy and practice largely on the back of the Education for All (EFA) objectives, the Millennium Development Goals (MDGs) and the neo-liberal logics which have championed state retreat in favour of private sector ascendance in globalised development. This, in conjunction with the persistent struggles of educational transformation in the Global South, has given NGOs little trouble in legitimising their prominent presence in education and other sectors of socio-economic relief in these parts of the world. Little illusion remains however, in many commentary circles, of the role of NGOs in advancing development ideals, the honesty of their altruistic intents, their ideological leanings as well as their efficacy in carrying out their mandates. As such, the logics which have been used to dethrone developing state structures in order to expand the space for private intervention along with the prevailing and deepening markers of educational underperformance, have been central features of the criticisms levelled against NGOs. This thesis intervenes in these ongoing reflections by describing the role of NGOs in educational outcomes, particularly learner performance and retention in Joza. This analysis demonstrates the organisational, sector-level and broader community forces which influence not only the form which non-state interventions take on and the daily preoccupations of their carriers but broadly, the position they occupy in the town’s overall educational profile. By way of locating NGOs within Grahamstown’s educational landscape, this thesis first demonstrates, the conflicted nature of NGO operations from an international, sectoral, national, local and organisational level. The discussion then illustrates how the preoccupations of NGOs are scattered between the different communities which they occupy within these levels. Their reliance on these players demands that organisations be tactical in guarding both their survival and, at times, the conflicting allegiances which grant them different forms of legitimacy. Internal struggles which characterise this imbalance of forces results in a trade-off which often favours organisational preservation mechanisms over systemic educational overhaul. As such, while non-state interveners can be lauded for extending educational support to those who would otherwise not have such, the gains of NGO intervention are often absorbed by internal urgencies for organisational legitimacy and preservation. This, in a context which possesses a unique set of socio-economic and educational deficits that require, at the very least, radical and unbridled mediation, means that pre-existing inequalities in educational inputs and outcomes along with the resultant inequities in youth socio-economic prospects, can find refuge in the very sector whose support and intervention is sought out and justified for such. This thesis lays out the nuances of these tensions and contradictions and offers this case as a point of reference for further considerations of the persistent markers of underperformance which characterise developing communities that enjoy high concentrations of non-state educational intervention.
- Full Text:
- Date Issued: 2019