Comparative biogeography and ecology of freshwater fishes in the Breede and associated river systems, South Africa
- Authors: Chakona, Albert
- Date: 2012
- Subjects: Freshwater fishes -- South Africa -- Breede River , Freshwater fishes -- South Africa -- Geographical distribution , Freshwater fishes -- Ecology , Feshwater fishes -- Genetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5372 , http://hdl.handle.net/10962/d1015694
- Description: Distribution patterns and levels of genetic diversity in extant taxa are a product of complex palaeogeographic processes and climatic oscillations as well as the species’ intrinsic ecological adaptations. The Cape Floristic Region of South Africa presents a unique system for studying the processes that promote species diversification and distribution patterns. This region has a high degree of endemism of both terrestrial and aquatic biota and is clearly isolated from neighbouring areas by the Cape Fold Mountains and the Great Escarpment. The objective of this study was to firstly examine the ecology of freshwater fishes belonging to the genera Galaxias, Pseudobarbus and Sandelia in the south-western CFR. This was followed by an assessment of the genetic diversity of these taxa. Unique lineages were identified and their distribution was mapped. The work aimed to explore the role of the region’s complex palaeogeographic and climatic history as well as the role of the species’ ecological adaptations in driving lineage diversification and shaping contemporary distribution patterns. The four main components of the study can be summarised as follows: 1. Habitat associations of three widely distributed lineages of Galaxias zebratus Pseudobarbus burchelli and Sandelia capensis were evaluated at multiple localities in minimally disturbed mountain tributaries of the Breede, Duiwenhoks and Goukou River systems. The lineages have distinct habitat associations which were related to differences in their morphological traits. The slender-bodied Galaxias ‘nebula’ and the fusiform-shaped Pseudobarbus ‘Breede’ are capable of exploiting upper reaches with faster water velocity. By contrast, the laterally compressed Sandelia ‘eastern’ is restricted to lower reaches, making this lineage more susceptible to a wide array of impacts. 2. A recently discovered lineage of Galaxias zebratus, (Galaxias ‘nebula’), was found to be capable of tolerating emersion for a prolonged period of time. This is the first time that such capabilities have been documented in an African galaxiid. These adaptations have implications for the interpretation of Galaxias ‘nebula’s wide distribution range. 3. The phylogeography of Galaxias ‘nebula’ across its entire distribution range was investigated using two mitochondrial genes (cytochrome c oxidase subunit I (COI) and cytochrome b (cyt b)). This lineage has a complex evolutionary history that was influenced by both intrinsic and extrinsic factors. Rare events such as episodic drainage connections during Pleistocene and Holocene pluvial periods, possibly augmented by river confluences during periods of lower sea-levels and river capture events seem to be the most credible explanation for the extensive contemporary distribution and the relatively shallow genetic divergence between different river systems. 4. Mitochondrial cyt b sequences were used (i) to assess genetic diversity in G. zebratus, P. burchelli and S. capensis from the south-western CFR and (ii) to determine the roles of intrinsic ecological adaptations and extrinsic landscape and climatic changes in promoting genetic diversification and shaping present day distribution patterns of lineages in the three taxa. Marine incursions during periods of major sea-level transgressions are proposed to have isolated populations in upland refugia, thereby driving allopatric divergence in these species. Subsequent connections of rivers during wetter periods and lower sea-levels are proposed to have facilitated post-speciation dispersal of lineages to attain present day distribution patterns. While detailed morphological studies and further genetic analysis are needed to substantiate the taxonomic status of the newly discovered lineages of Galaxias zebratus, Pseudobarbus burchelli and Sandelia capensis, results of the present study indicate that the south-western CFR represents a previously unrecognised centre of freshwater fish diversity and microendemism in the broader Cape Floristic Region. Accurate identification of lineages and comprehensive mapping of their distribution is a fundamental pre-requisite for ecological studies, assessing conservation status and implementation of appropriate conservation measures.
- Full Text:
- Date Issued: 2012
- Authors: Chakona, Albert
- Date: 2012
- Subjects: Freshwater fishes -- South Africa -- Breede River , Freshwater fishes -- South Africa -- Geographical distribution , Freshwater fishes -- Ecology , Feshwater fishes -- Genetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5372 , http://hdl.handle.net/10962/d1015694
- Description: Distribution patterns and levels of genetic diversity in extant taxa are a product of complex palaeogeographic processes and climatic oscillations as well as the species’ intrinsic ecological adaptations. The Cape Floristic Region of South Africa presents a unique system for studying the processes that promote species diversification and distribution patterns. This region has a high degree of endemism of both terrestrial and aquatic biota and is clearly isolated from neighbouring areas by the Cape Fold Mountains and the Great Escarpment. The objective of this study was to firstly examine the ecology of freshwater fishes belonging to the genera Galaxias, Pseudobarbus and Sandelia in the south-western CFR. This was followed by an assessment of the genetic diversity of these taxa. Unique lineages were identified and their distribution was mapped. The work aimed to explore the role of the region’s complex palaeogeographic and climatic history as well as the role of the species’ ecological adaptations in driving lineage diversification and shaping contemporary distribution patterns. The four main components of the study can be summarised as follows: 1. Habitat associations of three widely distributed lineages of Galaxias zebratus Pseudobarbus burchelli and Sandelia capensis were evaluated at multiple localities in minimally disturbed mountain tributaries of the Breede, Duiwenhoks and Goukou River systems. The lineages have distinct habitat associations which were related to differences in their morphological traits. The slender-bodied Galaxias ‘nebula’ and the fusiform-shaped Pseudobarbus ‘Breede’ are capable of exploiting upper reaches with faster water velocity. By contrast, the laterally compressed Sandelia ‘eastern’ is restricted to lower reaches, making this lineage more susceptible to a wide array of impacts. 2. A recently discovered lineage of Galaxias zebratus, (Galaxias ‘nebula’), was found to be capable of tolerating emersion for a prolonged period of time. This is the first time that such capabilities have been documented in an African galaxiid. These adaptations have implications for the interpretation of Galaxias ‘nebula’s wide distribution range. 3. The phylogeography of Galaxias ‘nebula’ across its entire distribution range was investigated using two mitochondrial genes (cytochrome c oxidase subunit I (COI) and cytochrome b (cyt b)). This lineage has a complex evolutionary history that was influenced by both intrinsic and extrinsic factors. Rare events such as episodic drainage connections during Pleistocene and Holocene pluvial periods, possibly augmented by river confluences during periods of lower sea-levels and river capture events seem to be the most credible explanation for the extensive contemporary distribution and the relatively shallow genetic divergence between different river systems. 4. Mitochondrial cyt b sequences were used (i) to assess genetic diversity in G. zebratus, P. burchelli and S. capensis from the south-western CFR and (ii) to determine the roles of intrinsic ecological adaptations and extrinsic landscape and climatic changes in promoting genetic diversification and shaping present day distribution patterns of lineages in the three taxa. Marine incursions during periods of major sea-level transgressions are proposed to have isolated populations in upland refugia, thereby driving allopatric divergence in these species. Subsequent connections of rivers during wetter periods and lower sea-levels are proposed to have facilitated post-speciation dispersal of lineages to attain present day distribution patterns. While detailed morphological studies and further genetic analysis are needed to substantiate the taxonomic status of the newly discovered lineages of Galaxias zebratus, Pseudobarbus burchelli and Sandelia capensis, results of the present study indicate that the south-western CFR represents a previously unrecognised centre of freshwater fish diversity and microendemism in the broader Cape Floristic Region. Accurate identification of lineages and comprehensive mapping of their distribution is a fundamental pre-requisite for ecological studies, assessing conservation status and implementation of appropriate conservation measures.
- Full Text:
- Date Issued: 2012
Conveniencing the family in agri-based processing enterprise : a grounded theory study of strategic leaders' cultural assumptions and strategising activities
- Authors: Kanyangale, Macdonald Isaac
- Date: 2012
- Subjects: Small business -- Malawi -- Management Agriculture -- Malawi -- Business management Agriculture -- Economic aspects -- Malawi Grounded theory -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1181 , http://hdl.handle.net/10962/d1002798
- Description: As leaders of small and medium enterprises (SMEs), strategic leaders are responsible for strategising, the approach to which is influenced by their cultural paradigm. The effects of this strategising are manifested in the day-to-day activities of these leaders. This study aims to build an understanding of the shared cultural assumptions of strategic leaders in agri-based processing SMEs and how these assumptions affect the strategising activities that are adopted when addressing critical incidents related to the internal integration and external adaptation of the SME. Using Strauss and Corbin‟s (1990) grounded theory method, this study develops a theory titled Conveniencing the Family in Business, which is induced from critical incidents. A sample of critical incidents was gathered from 44 qualitative interviews conducted with strategic leaders of various agri-based processing SMEs operating in Malawi. This study found that strategic leaders display persistent and stable pragmatic business survival mind sets, but dynamic cultural assumptions about relationships with organisation members. The cultural influence of these assumptions is manifested in two distinctive and alternative processes making up the theory of conveniencing the family in business. These are the humanising and commodifying of relationships with organisation members, and they are evident in hostile and friendly business environments, respectively. Humanising of relationships with all members of the organisation builds and capitalises on inclusive, organisation-wide social capital that secures the future of the business. On the other hand, commodifying of relationships with non-family organisation members weakens collective support, which becomes mainly dependent on family and friendship ties. Thus, commodifying of relationships serves to perpetuate the close integration of business activity and family requirements to ultimately convenience the family in business, and represents the desired modus operandi of strategic leaders. As strategic leaders of SMEs have not yet conceptualised this, providing them with the conceptual theory developed here may be helpful towards a consistent re-orientation of the internal organisational support in a way that does not exclude but rather harnesses the wider solidarity of organisation members. The process explained by this theory is iterative, dynamic and distinguishes patterns of relationships amongst organisation members, which either enhances or compromises their collective support for the leaders and the enterprise. This by implication affects the performance of the enterprise. The results of this study are discussed from the perspective of social exchange and social capital theory, thereby contributing to the understanding of the strategising activities of strategic leaders, as well as the processes of building or destroying social capital in this type of enterprise.
- Full Text:
- Date Issued: 2012
- Authors: Kanyangale, Macdonald Isaac
- Date: 2012
- Subjects: Small business -- Malawi -- Management Agriculture -- Malawi -- Business management Agriculture -- Economic aspects -- Malawi Grounded theory -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1181 , http://hdl.handle.net/10962/d1002798
- Description: As leaders of small and medium enterprises (SMEs), strategic leaders are responsible for strategising, the approach to which is influenced by their cultural paradigm. The effects of this strategising are manifested in the day-to-day activities of these leaders. This study aims to build an understanding of the shared cultural assumptions of strategic leaders in agri-based processing SMEs and how these assumptions affect the strategising activities that are adopted when addressing critical incidents related to the internal integration and external adaptation of the SME. Using Strauss and Corbin‟s (1990) grounded theory method, this study develops a theory titled Conveniencing the Family in Business, which is induced from critical incidents. A sample of critical incidents was gathered from 44 qualitative interviews conducted with strategic leaders of various agri-based processing SMEs operating in Malawi. This study found that strategic leaders display persistent and stable pragmatic business survival mind sets, but dynamic cultural assumptions about relationships with organisation members. The cultural influence of these assumptions is manifested in two distinctive and alternative processes making up the theory of conveniencing the family in business. These are the humanising and commodifying of relationships with organisation members, and they are evident in hostile and friendly business environments, respectively. Humanising of relationships with all members of the organisation builds and capitalises on inclusive, organisation-wide social capital that secures the future of the business. On the other hand, commodifying of relationships with non-family organisation members weakens collective support, which becomes mainly dependent on family and friendship ties. Thus, commodifying of relationships serves to perpetuate the close integration of business activity and family requirements to ultimately convenience the family in business, and represents the desired modus operandi of strategic leaders. As strategic leaders of SMEs have not yet conceptualised this, providing them with the conceptual theory developed here may be helpful towards a consistent re-orientation of the internal organisational support in a way that does not exclude but rather harnesses the wider solidarity of organisation members. The process explained by this theory is iterative, dynamic and distinguishes patterns of relationships amongst organisation members, which either enhances or compromises their collective support for the leaders and the enterprise. This by implication affects the performance of the enterprise. The results of this study are discussed from the perspective of social exchange and social capital theory, thereby contributing to the understanding of the strategising activities of strategic leaders, as well as the processes of building or destroying social capital in this type of enterprise.
- Full Text:
- Date Issued: 2012
Creating a space for integrative education within the sciences
- Authors: Van der Post, Leda
- Date: 2012
- Subjects: Computer science -- Vocational guidance , Education, Cooperative , Curriculum evaluation , Experiential learning -- Science
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10482 , http://hdl.handle.net/10948/d1012677 , Computer science -- Vocational guidance , Education, Cooperative , Curriculum evaluation , Experiential learning -- Science
- Description: This thesis documents an action research project that was carried out within the Department of Computing Sciences at the Nelson Mandela Metropolitan University (NMMU), South Africa, from January 2010 to December 2011. The overall aim of the research was to foster an environment in which academics could explore ways to teach using an integrative approach to education. Previous research within the department had raised the concern that students were graduating without the type of high-level cognitive skills that were required in the workplace. While the students’ technical skills were perceived as being excellent, employers indicated that students would benefit from opportunities to develop or improve skills such as communication, teamwork, innovative thinking and time management. These skills include high-level cognitive skills, and are often referred to as “soft skills”. The academics participating in the research project came to believe that it was essential to develop teaching methods that would provide opportunities for students to develop these soft skills, in conjunction with the content and technical knowledge currently addressed in their courses. The research project followed the living theory approach to action research. A living theory action research project allows the researcher to investigate her own teaching, and develop a theory of practice. The theory of practice can be applied to the issues under investigation, to improve the situation or solve problems. At the same time, the theory of practice can contribute to the body of knowledge within the academic domain of the research. Action research is an iterative, cyclical process. There were four research cycles, each one semester in length, during the two years of the project. The project will continue, with a fifth research cycle, starting in January 2012. By the end of the fourth research cycle—Semester Two, 2011—there were eleven academics actively participating in the research group. The project had extended its influence to include academics from the Department of Mathematics at NMMU. The academics ranged from senior, long-serving professors to junior lecturing staff. The results of the research, or the researcher-practitioner’s living theory, explain the process by which an effective and enthusiastic community of practice, dedicated to improving the academics’ teaching and learning practice, was developed. The living theory is applicable to academics within a scientific discipline, desiring to explore and improve their education practice. My living theory explains the characteristics of the TLC (The Learning Community) space, and the action strategies for creating such a space. The explanation of the process of this project includes an analysis of the development process of the research group, typical characteristics of the environment or “space” of the group, and action strategies that other academics could use to create a similar community of practice.
- Full Text:
- Date Issued: 2012
- Authors: Van der Post, Leda
- Date: 2012
- Subjects: Computer science -- Vocational guidance , Education, Cooperative , Curriculum evaluation , Experiential learning -- Science
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10482 , http://hdl.handle.net/10948/d1012677 , Computer science -- Vocational guidance , Education, Cooperative , Curriculum evaluation , Experiential learning -- Science
- Description: This thesis documents an action research project that was carried out within the Department of Computing Sciences at the Nelson Mandela Metropolitan University (NMMU), South Africa, from January 2010 to December 2011. The overall aim of the research was to foster an environment in which academics could explore ways to teach using an integrative approach to education. Previous research within the department had raised the concern that students were graduating without the type of high-level cognitive skills that were required in the workplace. While the students’ technical skills were perceived as being excellent, employers indicated that students would benefit from opportunities to develop or improve skills such as communication, teamwork, innovative thinking and time management. These skills include high-level cognitive skills, and are often referred to as “soft skills”. The academics participating in the research project came to believe that it was essential to develop teaching methods that would provide opportunities for students to develop these soft skills, in conjunction with the content and technical knowledge currently addressed in their courses. The research project followed the living theory approach to action research. A living theory action research project allows the researcher to investigate her own teaching, and develop a theory of practice. The theory of practice can be applied to the issues under investigation, to improve the situation or solve problems. At the same time, the theory of practice can contribute to the body of knowledge within the academic domain of the research. Action research is an iterative, cyclical process. There were four research cycles, each one semester in length, during the two years of the project. The project will continue, with a fifth research cycle, starting in January 2012. By the end of the fourth research cycle—Semester Two, 2011—there were eleven academics actively participating in the research group. The project had extended its influence to include academics from the Department of Mathematics at NMMU. The academics ranged from senior, long-serving professors to junior lecturing staff. The results of the research, or the researcher-practitioner’s living theory, explain the process by which an effective and enthusiastic community of practice, dedicated to improving the academics’ teaching and learning practice, was developed. The living theory is applicable to academics within a scientific discipline, desiring to explore and improve their education practice. My living theory explains the characteristics of the TLC (The Learning Community) space, and the action strategies for creating such a space. The explanation of the process of this project includes an analysis of the development process of the research group, typical characteristics of the environment or “space” of the group, and action strategies that other academics could use to create a similar community of practice.
- Full Text:
- Date Issued: 2012
Curriculum reform in Lesotho: exploring the interface between environmental education and geography in selected schools
- Authors: Raselimo, Mohaeka Gabriel
- Date: 2012
- Subjects: Curriculum planning -- Lesotho Curriculum change -- Lesotho Educational evaluation -- Lesotho Environmental education -- Study and teaching (Secondary) -- Lesotho Geography -- Study and teaching (Secondary) -- Lesotho Agenda 21 (Program)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1488 , http://hdl.handle.net/10962/d1003369
- Description: This study sought to explore the interface between environmental education (EE) and school geography with a view to understanding a process of curriculum reform in the context of Lesotho. The research was based on the curriculum reform process that was initiated by a Danish donor-funded project, known as the Lesotho Environmental Education Support Project (LEESP), which operated from 2001 to 2004. Driven by a sustainable development imperative, the project was intended to assist Lesotho in the implementation of local action for Agenda 21 by introducing environmental education into the formal education system. Deviating slightly from much published research on geographical and environmental education, which focuses on how geography contributes to environmental education, this study explored how the latter has shaped the former in terms of content and pedagogy. Using the lens of critical curriculum theory, I sought to understand the political nature of the curriculum and of curriculum change, focusing on the LEESP curriculum policy development, dissemination and implementation at classroom level. The study employed Bernstein's concepts of classification and framing to illuminate issues of power and control between discourses, and between teachers and learners. Operating within an interpretive qualitative research orientation, the study used a case study method focusing on five secondary/high schools in Lesotho. The data was generated through document analysis, interviews and classroom observations. The study examined the assumptions, values and ideologies underpinning environmental education curriculum intentions as reflected in LEESP documents. It also investigated the social process of conceptualising and disseminating environmental education to understand the challenges faced as education practitioners made sense of environmental education innovations in the specific contexts of Lesotho, and how these could possibly influence what happens at the classroom level. The analysis of the LEESP documents revealed that while there are many areas of synergy between the LEESP environmental education policy guidelines and the national education ideals in Lesotho, achievement of the transformational visions of action competence, which was the overarching concept in the reform process, would require major structural changes. The study also highlights issues of participation, contestations, tensions and contradictions associated with the conceptualisation and dissemination of environmental education. At implementation level, there is a disjuncture between environmental education policy intentions and practice. Geography teachers in the research schools generally understood the existence of environmental education in their schools in terms of environmental management. The findings also revealed that while there is generally a strong environmental dimension in geography content, as reflected in both curriculum materials and classroom practice, the subject still retains its disciplinary boundaries and makes little use of knowledge from other subjects or the everyday knowledge of the learners. Finally, it emerged that while the geography teachers in their rhetoric espoused learner-centred methods, in practice they generally employed traditional teacher-centred and book-centred methods. The study concludes that a lack of change in school geography in Lesotho, of the sort envisaged in LEESP, may be attributed to contextual and structural factors such as an overemphasis on examinations, and certain perceptions on the part of teachers and learners embedded in the history and culture of their society. A model of teacher professional development capable of supporting curriculum change is therefore proposed.
- Full Text:
- Date Issued: 2012
- Authors: Raselimo, Mohaeka Gabriel
- Date: 2012
- Subjects: Curriculum planning -- Lesotho Curriculum change -- Lesotho Educational evaluation -- Lesotho Environmental education -- Study and teaching (Secondary) -- Lesotho Geography -- Study and teaching (Secondary) -- Lesotho Agenda 21 (Program)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1488 , http://hdl.handle.net/10962/d1003369
- Description: This study sought to explore the interface between environmental education (EE) and school geography with a view to understanding a process of curriculum reform in the context of Lesotho. The research was based on the curriculum reform process that was initiated by a Danish donor-funded project, known as the Lesotho Environmental Education Support Project (LEESP), which operated from 2001 to 2004. Driven by a sustainable development imperative, the project was intended to assist Lesotho in the implementation of local action for Agenda 21 by introducing environmental education into the formal education system. Deviating slightly from much published research on geographical and environmental education, which focuses on how geography contributes to environmental education, this study explored how the latter has shaped the former in terms of content and pedagogy. Using the lens of critical curriculum theory, I sought to understand the political nature of the curriculum and of curriculum change, focusing on the LEESP curriculum policy development, dissemination and implementation at classroom level. The study employed Bernstein's concepts of classification and framing to illuminate issues of power and control between discourses, and between teachers and learners. Operating within an interpretive qualitative research orientation, the study used a case study method focusing on five secondary/high schools in Lesotho. The data was generated through document analysis, interviews and classroom observations. The study examined the assumptions, values and ideologies underpinning environmental education curriculum intentions as reflected in LEESP documents. It also investigated the social process of conceptualising and disseminating environmental education to understand the challenges faced as education practitioners made sense of environmental education innovations in the specific contexts of Lesotho, and how these could possibly influence what happens at the classroom level. The analysis of the LEESP documents revealed that while there are many areas of synergy between the LEESP environmental education policy guidelines and the national education ideals in Lesotho, achievement of the transformational visions of action competence, which was the overarching concept in the reform process, would require major structural changes. The study also highlights issues of participation, contestations, tensions and contradictions associated with the conceptualisation and dissemination of environmental education. At implementation level, there is a disjuncture between environmental education policy intentions and practice. Geography teachers in the research schools generally understood the existence of environmental education in their schools in terms of environmental management. The findings also revealed that while there is generally a strong environmental dimension in geography content, as reflected in both curriculum materials and classroom practice, the subject still retains its disciplinary boundaries and makes little use of knowledge from other subjects or the everyday knowledge of the learners. Finally, it emerged that while the geography teachers in their rhetoric espoused learner-centred methods, in practice they generally employed traditional teacher-centred and book-centred methods. The study concludes that a lack of change in school geography in Lesotho, of the sort envisaged in LEESP, may be attributed to contextual and structural factors such as an overemphasis on examinations, and certain perceptions on the part of teachers and learners embedded in the history and culture of their society. A model of teacher professional development capable of supporting curriculum change is therefore proposed.
- Full Text:
- Date Issued: 2012
Deciding and doing what's right for people and planet : an investigation of the ethics-oriented learning of novice environmental educators
- Authors: Olvitt, Lausanne Laura
- Date: 2012
- Subjects: Environmental education Environmental ethics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1913 , http://hdl.handle.net/10962/d1007238
- Description: This study probes the ethics-oriented reflexive deliberations of three novice environmental education practitioners in South Africa. Two of the cases examined work in a local government context, and the third in an environmental non-governmental organisation context. All three practitioners are studying a one-year professional development course in environmental education. The research asks how their ethical deliberations ‘come to be what they are’, at the interface of their workplace and course-based learning processes. Working within a relational, social realist ontology, the study takes a sociocultural-historical approach to learning, development and social change. Cultural-historical activity theory (CHAT) provides theoretical tools and a descriptive language to approach the rich, qualitative data derived from workplace and course observations, extensive interviews, and document review. Critical discourse analysis was used as a secondary analytical tool to probe ethical and environmental discourses that were found to be influential in the course and workplace activity systems. Data from the three case studies was analysed in stages. In the first stage, CHAT provided a theoretical perspective and language of description to analyse the interacting activity systems in which each learner-practitioner’s ethics-oriented reflexive deliberations occurred. This provided a platform for the second stage of analysis which was framed by Margaret Archer’s (1995) social realist theory of morphogenesis/ morphostasis, followed by a summative retroductive analysis, to give an account of the interplay of historically-emergent social and cultural structures and individual reflexivity in relation to the ethical dimensions of environmental education practice. The study traces how ethics-oriented reflexive deliberations occur at the untidy, unpredictable intersection of workplace, course and personal contexts, and are strongest when they are situated in authentic contexts that resonate with learner-practitioners’ ‘ultimate concerns’ (after Archer, 2003; 2007). In this study, the learner-practitioners’ ‘ultimate concerns’ included family, personal well-being, social justice, cultural identity and religious commitments. The scope and depth of learner-practitioners’ social-ecological knowledge was also identified as a key factor influencing ethics-oriented reflexive deliberations, although the mediation of such knowledge can be hindered by language and conceptual ii barriers, amongst others. The study also noted how ethical positions circulating in the workplace, course and personal contexts were diverse, uneven and dynamic. Some ethical positions were found to be more explicitly differentiated than others, either resonating with or being overlooked by the learner-practitioners as they deliberated the ethical dimensions of their environmental education practice. In situations where there was limited depth, conceptual clarity and/ or confidence to engage directly with ethical concerns, there was a tendency towards (inadvertent) ethical relativism. Insights derived from the study suggest that these factors have limiting effects on the ethics-oriented reflexive deliberations of novice environmental educators. These insights point to the need for ethical deliberations to be re-personalised in context and underpinned by depth knowledge. A relational and pragmatic approach to environmental ethics (that recognises the validity of judgemental rationality – which can be fallible – and which seeks out practical adequacy) is put forward as appropriate and potentially generative in environmental education and training processes. This would need to be supported by careful attention to the influence of environmental discourses and practices in shaping ethical deliberations, and may also be helpful in developing a much-needed accessible, everyday language of ethical engagement. This study’s contribution to new knowledge in the field of environmental education is through its account of ethics-oriented reflexive deliberations emerging (in the Archerian morphogenetic sense) in complex, indeterminate ways at the interface of sociocultural and social-ecological contexts. The ethics-oriented reflexive deliberations of novice environmental educators occur in relation to their ‘ultimate concerns’ and are advanced or hindered by the historically-emergent practices, discourses and material realities of their workplace, personal and educational contexts. These insights require that the complex interplay of intersecting contexts and concerns that shape ethics-oriented reflexive deliberations be acknowledged and carefully mediated in both workplace-based and coursebased professional development processes.
- Full Text:
- Date Issued: 2012
- Authors: Olvitt, Lausanne Laura
- Date: 2012
- Subjects: Environmental education Environmental ethics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1913 , http://hdl.handle.net/10962/d1007238
- Description: This study probes the ethics-oriented reflexive deliberations of three novice environmental education practitioners in South Africa. Two of the cases examined work in a local government context, and the third in an environmental non-governmental organisation context. All three practitioners are studying a one-year professional development course in environmental education. The research asks how their ethical deliberations ‘come to be what they are’, at the interface of their workplace and course-based learning processes. Working within a relational, social realist ontology, the study takes a sociocultural-historical approach to learning, development and social change. Cultural-historical activity theory (CHAT) provides theoretical tools and a descriptive language to approach the rich, qualitative data derived from workplace and course observations, extensive interviews, and document review. Critical discourse analysis was used as a secondary analytical tool to probe ethical and environmental discourses that were found to be influential in the course and workplace activity systems. Data from the three case studies was analysed in stages. In the first stage, CHAT provided a theoretical perspective and language of description to analyse the interacting activity systems in which each learner-practitioner’s ethics-oriented reflexive deliberations occurred. This provided a platform for the second stage of analysis which was framed by Margaret Archer’s (1995) social realist theory of morphogenesis/ morphostasis, followed by a summative retroductive analysis, to give an account of the interplay of historically-emergent social and cultural structures and individual reflexivity in relation to the ethical dimensions of environmental education practice. The study traces how ethics-oriented reflexive deliberations occur at the untidy, unpredictable intersection of workplace, course and personal contexts, and are strongest when they are situated in authentic contexts that resonate with learner-practitioners’ ‘ultimate concerns’ (after Archer, 2003; 2007). In this study, the learner-practitioners’ ‘ultimate concerns’ included family, personal well-being, social justice, cultural identity and religious commitments. The scope and depth of learner-practitioners’ social-ecological knowledge was also identified as a key factor influencing ethics-oriented reflexive deliberations, although the mediation of such knowledge can be hindered by language and conceptual ii barriers, amongst others. The study also noted how ethical positions circulating in the workplace, course and personal contexts were diverse, uneven and dynamic. Some ethical positions were found to be more explicitly differentiated than others, either resonating with or being overlooked by the learner-practitioners as they deliberated the ethical dimensions of their environmental education practice. In situations where there was limited depth, conceptual clarity and/ or confidence to engage directly with ethical concerns, there was a tendency towards (inadvertent) ethical relativism. Insights derived from the study suggest that these factors have limiting effects on the ethics-oriented reflexive deliberations of novice environmental educators. These insights point to the need for ethical deliberations to be re-personalised in context and underpinned by depth knowledge. A relational and pragmatic approach to environmental ethics (that recognises the validity of judgemental rationality – which can be fallible – and which seeks out practical adequacy) is put forward as appropriate and potentially generative in environmental education and training processes. This would need to be supported by careful attention to the influence of environmental discourses and practices in shaping ethical deliberations, and may also be helpful in developing a much-needed accessible, everyday language of ethical engagement. This study’s contribution to new knowledge in the field of environmental education is through its account of ethics-oriented reflexive deliberations emerging (in the Archerian morphogenetic sense) in complex, indeterminate ways at the interface of sociocultural and social-ecological contexts. The ethics-oriented reflexive deliberations of novice environmental educators occur in relation to their ‘ultimate concerns’ and are advanced or hindered by the historically-emergent practices, discourses and material realities of their workplace, personal and educational contexts. These insights require that the complex interplay of intersecting contexts and concerns that shape ethics-oriented reflexive deliberations be acknowledged and carefully mediated in both workplace-based and coursebased professional development processes.
- Full Text:
- Date Issued: 2012
Development of a hydraulic sub-model as part of a desktop environmental flow assessment method
- Authors: Desai, Ahmed Yacoob
- Date: 2012
- Subjects: Hydrologic models -- Research -- South Africa Hydraulic engineering -- South Africa Rivers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6041 , http://hdl.handle.net/10962/d1006200
- Description: Countries around the world have been developing ecological policies to protect their water resources and minimise the impacts of development on their river systems. The concept of ‘minimum flows’ was initially established as a solution but it did not provide sufficient protection as all elements of a flow regime were found to be important for the protection of the river ecosystem. “Environmental flows” were developed to determine these flow regimes to maintain a river in some defined ecological condition. Rapid, initial estimates of the quantity component of environmental flows may be determined using the Desktop Reserve Model in South Africa. However, the Desktop Reserve Model is dependent upon the characteristics of the reference natural hydrology used. The advancements in hydraulic and ecological relationships from the past decade have prompted the development of a Revised Desktop Reserve Model (RDRM) that would incorporate these relationships. The research in this thesis presents the development of the hydraulic sub-model for the RDRM. The hydraulic sub-model was designed to produce a realistic representation of the hydraulic conditions using hydraulic parameters/characteristics from readily available information for any part of South Africa. Hydraulic data from past EWR studies were used to estimate the hydraulic parameters. These estimated hydraulic parameters were used to develop hydraulic estimation relationships and these relationships were developed based on a combination of regression and rule-based procedures. The estimation relationships were incorporated into the hydraulic sub-model of the integrated RDRM and assessments of the hydraulic outputs and EWR results were undertaken to assess the ‘applicability’ of the hydraulic sub-model. The hydraulic sub-model was assessed to be at a stage where it can satisfactorily be incorporated in the RDRM and that it is adequately robust in many situations. Recommendations for future work include the refinement of estimation of the channel forming discharge or the use of spatial imagery to check the maximum channel width estimation. It is also proposed that a future version of the hydraulic sub-model could include flow regime change impacts on channel geomorphology and sedimentology so that flow management scenarios can be more effectively assessed.
- Full Text:
- Date Issued: 2012
- Authors: Desai, Ahmed Yacoob
- Date: 2012
- Subjects: Hydrologic models -- Research -- South Africa Hydraulic engineering -- South Africa Rivers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6041 , http://hdl.handle.net/10962/d1006200
- Description: Countries around the world have been developing ecological policies to protect their water resources and minimise the impacts of development on their river systems. The concept of ‘minimum flows’ was initially established as a solution but it did not provide sufficient protection as all elements of a flow regime were found to be important for the protection of the river ecosystem. “Environmental flows” were developed to determine these flow regimes to maintain a river in some defined ecological condition. Rapid, initial estimates of the quantity component of environmental flows may be determined using the Desktop Reserve Model in South Africa. However, the Desktop Reserve Model is dependent upon the characteristics of the reference natural hydrology used. The advancements in hydraulic and ecological relationships from the past decade have prompted the development of a Revised Desktop Reserve Model (RDRM) that would incorporate these relationships. The research in this thesis presents the development of the hydraulic sub-model for the RDRM. The hydraulic sub-model was designed to produce a realistic representation of the hydraulic conditions using hydraulic parameters/characteristics from readily available information for any part of South Africa. Hydraulic data from past EWR studies were used to estimate the hydraulic parameters. These estimated hydraulic parameters were used to develop hydraulic estimation relationships and these relationships were developed based on a combination of regression and rule-based procedures. The estimation relationships were incorporated into the hydraulic sub-model of the integrated RDRM and assessments of the hydraulic outputs and EWR results were undertaken to assess the ‘applicability’ of the hydraulic sub-model. The hydraulic sub-model was assessed to be at a stage where it can satisfactorily be incorporated in the RDRM and that it is adequately robust in many situations. Recommendations for future work include the refinement of estimation of the channel forming discharge or the use of spatial imagery to check the maximum channel width estimation. It is also proposed that a future version of the hydraulic sub-model could include flow regime change impacts on channel geomorphology and sedimentology so that flow management scenarios can be more effectively assessed.
- Full Text:
- Date Issued: 2012
Development of a value based pricing index for new drugs in metastatic colorectal cancer
- Authors: Dranitsaris, George
- Date: 2012
- Subjects: Drug -- Prices , Prescription pricing , Pharmaceutical industry -- Prices
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10140 , http://hdl.handle.net/10948/d1009310 , Drug -- Prices , Prescription pricing , Pharmaceutical industry -- Prices
- Description: Background: Worldwide, prices for cancer drugs have been under downward pressure where several governments have mandated price cuts of branded and generic products. A better alternative to mandated price cuts would be the estimation of a launch price based on drug performance, cost effectiveness and a country’s ability to pay. In this study, the development of a global pricing index for new drugs that encompasses all of these attributes in patients with metastatic colorectal cancer (mCRC) is described. Methods: A pharmacoeconomic model was developed to simulate clinical outcomes in mCRC patients receiving chemotherapy with the addition of a “new drug” that improves survival by 1.4, 3 and 6 months. Cost and health state utility data were obtained from cancer centers and oncology nurses (total n=112) in Canada (n=24), Spain (n=24), India (n=24), South Africa (n=16) and Malaysia (n=24). A price per dose was estimated for each survival increment using a target value threshold of three times the per capita gross domestic product (GDP) for each country, as recommended by the World Health Organisation (WHO). Multivariable analysis was then used to develop the pricing index, which considers survival benefit, per capita GDP and income dispersion as measured by the Gini coefficient as predictor variables. Results: Higher survival benefits were associated with elevated drug prices, especially in wealthier countries such as Canada and Spain. For a nation like Argentina with a per capita GDP of $15,000 and a Gini coefficient of 51, it is estimated that for a drug which provides a 4 month survival benefit in mCRC, the value based price would be $US 630 per dose. In contrast, the same drug in a wealthier country like Norway could command a price of $US 2,775 and still be considered cost effective according to the WHO criteria. Conclusions: A global pricing index was presented that can be used to estimate a value based price in different countries for new drugs in mCRC. The application of this index to estimate a price based on cost effectiveness would be a good starting point for opening dialogue between the key stakeholders and a better alternative to governments’ mandated price cuts.
- Full Text:
- Date Issued: 2012
- Authors: Dranitsaris, George
- Date: 2012
- Subjects: Drug -- Prices , Prescription pricing , Pharmaceutical industry -- Prices
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10140 , http://hdl.handle.net/10948/d1009310 , Drug -- Prices , Prescription pricing , Pharmaceutical industry -- Prices
- Description: Background: Worldwide, prices for cancer drugs have been under downward pressure where several governments have mandated price cuts of branded and generic products. A better alternative to mandated price cuts would be the estimation of a launch price based on drug performance, cost effectiveness and a country’s ability to pay. In this study, the development of a global pricing index for new drugs that encompasses all of these attributes in patients with metastatic colorectal cancer (mCRC) is described. Methods: A pharmacoeconomic model was developed to simulate clinical outcomes in mCRC patients receiving chemotherapy with the addition of a “new drug” that improves survival by 1.4, 3 and 6 months. Cost and health state utility data were obtained from cancer centers and oncology nurses (total n=112) in Canada (n=24), Spain (n=24), India (n=24), South Africa (n=16) and Malaysia (n=24). A price per dose was estimated for each survival increment using a target value threshold of three times the per capita gross domestic product (GDP) for each country, as recommended by the World Health Organisation (WHO). Multivariable analysis was then used to develop the pricing index, which considers survival benefit, per capita GDP and income dispersion as measured by the Gini coefficient as predictor variables. Results: Higher survival benefits were associated with elevated drug prices, especially in wealthier countries such as Canada and Spain. For a nation like Argentina with a per capita GDP of $15,000 and a Gini coefficient of 51, it is estimated that for a drug which provides a 4 month survival benefit in mCRC, the value based price would be $US 630 per dose. In contrast, the same drug in a wealthier country like Norway could command a price of $US 2,775 and still be considered cost effective according to the WHO criteria. Conclusions: A global pricing index was presented that can be used to estimate a value based price in different countries for new drugs in mCRC. The application of this index to estimate a price based on cost effectiveness would be a good starting point for opening dialogue between the key stakeholders and a better alternative to governments’ mandated price cuts.
- Full Text:
- Date Issued: 2012
Development of molecularly imprinted polymer based solid phase extraction sorbents for the selective cleanup of food and pharmaceutical residue samples
- Authors: Batlokwa, Bareki Shima
- Date: 2012
- Subjects: Sorbents -- Research Nanofibers -- Research Aflatoxins -- Research Electrospinning -- Research Extraction (Chemistry) -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4309 , http://hdl.handle.net/10962/d1004967
- Description: This thesis presents the development of chlorophyll, cholic acid, aflatoxin B1 molecularly imprinted polymer (MIP) particles and cholic acid MIP nanofibers for application as selective solid phase extraction (SPE) sorbents. The particles were prepared by bulk polymerization and the nanofibers by a novel approach combining molecular imprinting and electrospinning technology. The AFB1 MIP particles were compared with an aflatoxin specific immunoextraction sorbent in cleaning-up and pre-concentrating aflatoxins from nut extracts. They both recorded high extraction efficiencies (EEs) of > 97 % in selectively extracting the aflatoxins (AFB1, AFB2, AFG1 and AFG2). High reproducibility marked by the low %RSDs of < 1% and low LODs of ≤ 0.02 ng/g were calculated in all cases. The LODs were within the monitoring requirements of the European Commission. The results were validated with a peanut butter certified reference material. The chlorophyll MIP on the other hand selectively removed chlorophyll that would otherwise interfere during pesticide residue analysis (PRA) from > 0.6 to <0.09 Au in green plants extracts. The extracted chlorophyll was removed to far below the level of ≥ 0.399 Au that is usually associated with interference during PRA. Furthermore, the MIP demonstrated better selectivity by removing only chlorophyll (> 99%) in the presence of planar pesticides than the currently employed graphitized carbon black (GCB) that removed both the chlorophyll (> 88%) and planar pesticides (> 89%). For the interfering cholic acid during drug residue analysis, cholic acid MIP electrospun nanofibers demonstrated to be more sensitive and possessing higher loading capacity than the MIP particles. 100% cholic acid was removed by the nanofibers from standard solutions relative to 80% by the particles. This showed that the nanofibers have better performance than the micro particles and as such have potential to replace the particle based SPE sorbents that are currently in use. All the templates were optimally removed from the prepared MIPs by employing a novel pressurized hot water extraction template removal method that was used for the first time in this thesis. The method employed only water, an environmentally friendly solvent to remove templates to ≥ 99.6% with template residual bleeding of ≤ 0.02%.
- Full Text:
- Date Issued: 2012
- Authors: Batlokwa, Bareki Shima
- Date: 2012
- Subjects: Sorbents -- Research Nanofibers -- Research Aflatoxins -- Research Electrospinning -- Research Extraction (Chemistry) -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4309 , http://hdl.handle.net/10962/d1004967
- Description: This thesis presents the development of chlorophyll, cholic acid, aflatoxin B1 molecularly imprinted polymer (MIP) particles and cholic acid MIP nanofibers for application as selective solid phase extraction (SPE) sorbents. The particles were prepared by bulk polymerization and the nanofibers by a novel approach combining molecular imprinting and electrospinning technology. The AFB1 MIP particles were compared with an aflatoxin specific immunoextraction sorbent in cleaning-up and pre-concentrating aflatoxins from nut extracts. They both recorded high extraction efficiencies (EEs) of > 97 % in selectively extracting the aflatoxins (AFB1, AFB2, AFG1 and AFG2). High reproducibility marked by the low %RSDs of < 1% and low LODs of ≤ 0.02 ng/g were calculated in all cases. The LODs were within the monitoring requirements of the European Commission. The results were validated with a peanut butter certified reference material. The chlorophyll MIP on the other hand selectively removed chlorophyll that would otherwise interfere during pesticide residue analysis (PRA) from > 0.6 to <0.09 Au in green plants extracts. The extracted chlorophyll was removed to far below the level of ≥ 0.399 Au that is usually associated with interference during PRA. Furthermore, the MIP demonstrated better selectivity by removing only chlorophyll (> 99%) in the presence of planar pesticides than the currently employed graphitized carbon black (GCB) that removed both the chlorophyll (> 88%) and planar pesticides (> 89%). For the interfering cholic acid during drug residue analysis, cholic acid MIP electrospun nanofibers demonstrated to be more sensitive and possessing higher loading capacity than the MIP particles. 100% cholic acid was removed by the nanofibers from standard solutions relative to 80% by the particles. This showed that the nanofibers have better performance than the micro particles and as such have potential to replace the particle based SPE sorbents that are currently in use. All the templates were optimally removed from the prepared MIPs by employing a novel pressurized hot water extraction template removal method that was used for the first time in this thesis. The method employed only water, an environmentally friendly solvent to remove templates to ≥ 99.6% with template residual bleeding of ≤ 0.02%.
- Full Text:
- Date Issued: 2012
Effect of cultivar on the quality of flax and hemp grown in South Africa
- Authors: Blouw, Langa Sunshine
- Date: 2012
- Subjects: Hemp -- South Africa , Flaxseed -- South Africa , Plant varieties , Textile industry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9387 , http://hdl.handle.net/10948/d1010997 , Hemp -- South Africa , Flaxseed -- South Africa , Plant varieties , Textile industry
- Description: Bast fibrous renewable materials, as commercial crops for the manufacture of textile based and other products, have been used for thousands of years to satisfy certain human needs, such as for shelter, clothing, source of energy and tools, and to sustain the livelihood of many communities in countries, such as in Asia, Europe and Africa. Concern for the environment has led to a number of global initiatives that favour the use of natural fibres. It is forecast that the global fibre demand by 2050 will be 130 million tonnes, which the cotton and synthetic fibre production will not be able to meet. Other than the environmental concerns, the renewed global interest in natural fibres, such as flax and hemp, forms part of a strategy to satisfy the fibre demand. South Africa, notwithstanding the fact that the flax and hemp industries have long been established for thousands of years in Europe, Asia and Egypt (Africa), has no history of the breeding, growing, processing and production of these cash crops. The renewed global interest in these crops has also stimulated interest from South Africa with respect to the development of a flax and hemp fibre industry so as to address some of the socio-economic challenges confronting the country today in its attempts to bring about real development in the rural areas through the cultivation and complete beneficiation of these fibre crops. In this regard, the relevant stakeholders, namely government, research councils, tertiary education institutions, farmers and communities worked together to investigate whether South Africa has the agronomic and climatic conditions, technical expertise as well as the necessary processing and production infrastructure to support the development of a local flax and hemp agro-industry. The purpose of this study was firstly to evaluate the performance of EU flax and hemp cultivars grown under different agronomic conditions in South Africa, and their effect on straw biomass yield, fibre yield and total fibre yield per hectare as well as associated fibre properties, and secondly to undertake mechanical fibre modification trials aimed at producing flax and hemp fibres with fibre diameters close to those of cotton. The minimum fibre diameter targeted being 20μm. In accordance with the project objectives and work plan, selected dew retted flax and hemp straw samples from the various planting sites selected by the Agriculture Research Council – Institute for Industrial Crops, representing all the agronomic conditions under investigation, were taken to the CSIR for fibre extraction and testing. A relatively inexpensive and easy to operate Russian designed and manufactured machine, the CMT-200M breaker-cum-scutcher, was used for fibre extraction and the resultant extracted fibre bundles were further refined, using a steel comb, to obtain optimal fibre separation before their physical and chemical properties were evaluated. Results obtained in this research study proved that the climatic and agronomic conditions in South Africa were suitable for the cultivation of flax and hemp, notwithstanding the fact that the fibre yields achieved for hemp were lower than the minimum criteria of 23 percent, and that for flax only just exceeded the 25 percent minimum. The lack of local technical expertise on the growing and retting of flax and hemp, contributed to the low fibre yields. The planting parameters which were found to produce good results for the cultivation of hemp were the October planting date, using a row spacing of between 12.5 to 25 cm, with a seeding density of between 80 – 100kg, and the application of 50 – 100kg nitrogen fertiliser. The use of extra artificial lighting and herbicide treatment did not appear to beneficially improve the hemp fibre yields. Similar considerations for flax cultivation in the Southern Cape region, particularly Oudtshoorn and Outeniqua, indicated that May to July planting dates, using inter-row spacing of 25cm and sowing density of 63kg seed.haˉ¹, produced a fibre yield and total fibre yield per hectare above the minimum values of 25 percent and 0,8 tonnes per hectare, respectively, quoted in the literature.
- Full Text:
- Date Issued: 2012
- Authors: Blouw, Langa Sunshine
- Date: 2012
- Subjects: Hemp -- South Africa , Flaxseed -- South Africa , Plant varieties , Textile industry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9387 , http://hdl.handle.net/10948/d1010997 , Hemp -- South Africa , Flaxseed -- South Africa , Plant varieties , Textile industry
- Description: Bast fibrous renewable materials, as commercial crops for the manufacture of textile based and other products, have been used for thousands of years to satisfy certain human needs, such as for shelter, clothing, source of energy and tools, and to sustain the livelihood of many communities in countries, such as in Asia, Europe and Africa. Concern for the environment has led to a number of global initiatives that favour the use of natural fibres. It is forecast that the global fibre demand by 2050 will be 130 million tonnes, which the cotton and synthetic fibre production will not be able to meet. Other than the environmental concerns, the renewed global interest in natural fibres, such as flax and hemp, forms part of a strategy to satisfy the fibre demand. South Africa, notwithstanding the fact that the flax and hemp industries have long been established for thousands of years in Europe, Asia and Egypt (Africa), has no history of the breeding, growing, processing and production of these cash crops. The renewed global interest in these crops has also stimulated interest from South Africa with respect to the development of a flax and hemp fibre industry so as to address some of the socio-economic challenges confronting the country today in its attempts to bring about real development in the rural areas through the cultivation and complete beneficiation of these fibre crops. In this regard, the relevant stakeholders, namely government, research councils, tertiary education institutions, farmers and communities worked together to investigate whether South Africa has the agronomic and climatic conditions, technical expertise as well as the necessary processing and production infrastructure to support the development of a local flax and hemp agro-industry. The purpose of this study was firstly to evaluate the performance of EU flax and hemp cultivars grown under different agronomic conditions in South Africa, and their effect on straw biomass yield, fibre yield and total fibre yield per hectare as well as associated fibre properties, and secondly to undertake mechanical fibre modification trials aimed at producing flax and hemp fibres with fibre diameters close to those of cotton. The minimum fibre diameter targeted being 20μm. In accordance with the project objectives and work plan, selected dew retted flax and hemp straw samples from the various planting sites selected by the Agriculture Research Council – Institute for Industrial Crops, representing all the agronomic conditions under investigation, were taken to the CSIR for fibre extraction and testing. A relatively inexpensive and easy to operate Russian designed and manufactured machine, the CMT-200M breaker-cum-scutcher, was used for fibre extraction and the resultant extracted fibre bundles were further refined, using a steel comb, to obtain optimal fibre separation before their physical and chemical properties were evaluated. Results obtained in this research study proved that the climatic and agronomic conditions in South Africa were suitable for the cultivation of flax and hemp, notwithstanding the fact that the fibre yields achieved for hemp were lower than the minimum criteria of 23 percent, and that for flax only just exceeded the 25 percent minimum. The lack of local technical expertise on the growing and retting of flax and hemp, contributed to the low fibre yields. The planting parameters which were found to produce good results for the cultivation of hemp were the October planting date, using a row spacing of between 12.5 to 25 cm, with a seeding density of between 80 – 100kg, and the application of 50 – 100kg nitrogen fertiliser. The use of extra artificial lighting and herbicide treatment did not appear to beneficially improve the hemp fibre yields. Similar considerations for flax cultivation in the Southern Cape region, particularly Oudtshoorn and Outeniqua, indicated that May to July planting dates, using inter-row spacing of 25cm and sowing density of 63kg seed.haˉ¹, produced a fibre yield and total fibre yield per hectare above the minimum values of 25 percent and 0,8 tonnes per hectare, respectively, quoted in the literature.
- Full Text:
- Date Issued: 2012
Electrochemical sensing and immunosensing using metallophthalocyanines and biomolecular modified surfaces
- Authors: Mashazi, Philani Nkosinathi
- Date: 2012
- Subjects: Phthalocyanines , Electrochemistry , Electrodes, Enzyme , Measles -- Measurement
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5580 , http://hdl.handle.net/10962/d1018248
- Description: The synthesis of cobalt and manganese phthalocyanine complexes bearing eight hexylthio and four amino substituents was carried out. The formation of thin films of these complexes using different modification methods was also studied. Hexylthio functionalized metallophthalocyanine complexes were immobilized onto gold electrode surfaces using the self-assembly techniques. Surface modifications using cobalt and manganese tetraamino phthalocyanine as polymers, monolayers (onto electrografted surfaces) and as carbon nanotube – metallophthalocyanine conjugates was also carried out. The new method of modifying gold electrodes with metal tetraamino phthalocyanine complexes was investigated. The modified electrode surfaces were studied for their electrocatalytic properties and as potential electrochemical sensors for the detection of hydrogen peroxide (H₂O₂). The limits of detection for the H₂O₂ were of the orders of ~10⁻⁷ M for all the modified electrodes. The modified electrodes gave very good analytical parameters; such as good sensitivity, linearity at studied concentration range and well-defined analytical peaks with increased current densities. The modification methods were reproducible, highly conducting thin films were formed and the modified electrodes were very stable. The design of electrochemical immunosensors for the detection of measles-specific antibodies was also carried out. The modified surface with measles-antigen as sensing element was accomplished using covalent immobilization for an intimate connection of the measles-antigen as a sensing layer onto an electrode surface. Two methods of detecting measles-specific antibodies were investigated and these methods were based on electrochemical impedance, i.e. label-free detection, and voltammetric method using horse-radish peroxidase (HRP) labeled antibody as a reporter. The detection of measles-specific antibodies was accomplished using both these methods. The potential applications of the designed immunosensor were evaluated in real samples (human and newborn calf serum) and the electrodes could detect the antibodies in the complex sample matrix with ease.
- Full Text:
- Date Issued: 2012
- Authors: Mashazi, Philani Nkosinathi
- Date: 2012
- Subjects: Phthalocyanines , Electrochemistry , Electrodes, Enzyme , Measles -- Measurement
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5580 , http://hdl.handle.net/10962/d1018248
- Description: The synthesis of cobalt and manganese phthalocyanine complexes bearing eight hexylthio and four amino substituents was carried out. The formation of thin films of these complexes using different modification methods was also studied. Hexylthio functionalized metallophthalocyanine complexes were immobilized onto gold electrode surfaces using the self-assembly techniques. Surface modifications using cobalt and manganese tetraamino phthalocyanine as polymers, monolayers (onto electrografted surfaces) and as carbon nanotube – metallophthalocyanine conjugates was also carried out. The new method of modifying gold electrodes with metal tetraamino phthalocyanine complexes was investigated. The modified electrode surfaces were studied for their electrocatalytic properties and as potential electrochemical sensors for the detection of hydrogen peroxide (H₂O₂). The limits of detection for the H₂O₂ were of the orders of ~10⁻⁷ M for all the modified electrodes. The modified electrodes gave very good analytical parameters; such as good sensitivity, linearity at studied concentration range and well-defined analytical peaks with increased current densities. The modification methods were reproducible, highly conducting thin films were formed and the modified electrodes were very stable. The design of electrochemical immunosensors for the detection of measles-specific antibodies was also carried out. The modified surface with measles-antigen as sensing element was accomplished using covalent immobilization for an intimate connection of the measles-antigen as a sensing layer onto an electrode surface. Two methods of detecting measles-specific antibodies were investigated and these methods were based on electrochemical impedance, i.e. label-free detection, and voltammetric method using horse-radish peroxidase (HRP) labeled antibody as a reporter. The detection of measles-specific antibodies was accomplished using both these methods. The potential applications of the designed immunosensor were evaluated in real samples (human and newborn calf serum) and the electrodes could detect the antibodies in the complex sample matrix with ease.
- Full Text:
- Date Issued: 2012
Electrochemistry and photophysicochemical studies of titanium, tantalum and vanadium phthalocyanines in the presence of nanomaterials
- Authors: Chauke, Vongani Portia
- Date: 2012
- Subjects: Phthalocyanines -- Synthesis Electrochemistry Titanium Tantalum Vanadium
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4313 , http://hdl.handle.net/10962/d1004971
- Description: The syntheses of tetra- and octa-substituted phthalocyanine complexes of titanium (IV) oxide vanadium (IV) oxide and tantalum (V) hydroxide and their electrochemical characterisation are presented in this work. The structures and purity of these complexes were confirmed by NMR, infrared and mass spectroscopies and elemental analysis. They show good solubility in most common solvents especially non-viscous solvents such as dichloromethane and chloroform. The cyclic voltammograms (CV) showed reversible to quasi reversible behavior for all the reduction couples and the oxidation peaks were irreversible. Spectroelectrochemistry of the complexes confirmed metal and ring redox processes for TaPc and TiPc derivatives and ring based processes only for VPc complexes. The synthesis of gold nanoparticles and their conjugation with the new phthalocyanines was carried out. Similarly, single walled carbon nanotubes were conjugated to selected tantalum complexes and the characterization of all the nanomaterials and their conjugates using different techniques that include TEM, XRD and AFM is also presented in this work. The photophysical and photochemical properties and photocatalytic oxidation of cyclohexene properties of the newly synthesised in the presence of gold nanoparticles were investigated. The compounds were stable, well within the stability range for phthalocyanines. The singlet oxygen quantum yield values increased drastically in the presence of gold nanoparticles. The photocatalytic products obtained from the reaction were cyclohexene oxide, 2-cyclohexen-1-ol, 2-cyclohexene-1-one and 1,4-cyclohexanediol. The percentage conversion values, yields and selectivity values improved significantly in the presence of AuNPs. Singlet oxygen was determined to be the main agent involved in the photocatalytic oxidation of cyclohexene. The electrocatalytic oxidation of bisphenol A and p-nitrophenol was carried out using nickel tetraamino phthalocyanine and all the newly synthesised metallophthalocyanine in the presence of gold nanoparticles and single walled carbon nanotubes. The charge transfer behaviour of AuNPs was enhanced in the presence of TaPc, TiPc and VPc complexes. The presence of single walled carbon nanotubes further improved electron transfer and minimised electrode passivation.
- Full Text:
- Date Issued: 2012
- Authors: Chauke, Vongani Portia
- Date: 2012
- Subjects: Phthalocyanines -- Synthesis Electrochemistry Titanium Tantalum Vanadium
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4313 , http://hdl.handle.net/10962/d1004971
- Description: The syntheses of tetra- and octa-substituted phthalocyanine complexes of titanium (IV) oxide vanadium (IV) oxide and tantalum (V) hydroxide and their electrochemical characterisation are presented in this work. The structures and purity of these complexes were confirmed by NMR, infrared and mass spectroscopies and elemental analysis. They show good solubility in most common solvents especially non-viscous solvents such as dichloromethane and chloroform. The cyclic voltammograms (CV) showed reversible to quasi reversible behavior for all the reduction couples and the oxidation peaks were irreversible. Spectroelectrochemistry of the complexes confirmed metal and ring redox processes for TaPc and TiPc derivatives and ring based processes only for VPc complexes. The synthesis of gold nanoparticles and their conjugation with the new phthalocyanines was carried out. Similarly, single walled carbon nanotubes were conjugated to selected tantalum complexes and the characterization of all the nanomaterials and their conjugates using different techniques that include TEM, XRD and AFM is also presented in this work. The photophysical and photochemical properties and photocatalytic oxidation of cyclohexene properties of the newly synthesised in the presence of gold nanoparticles were investigated. The compounds were stable, well within the stability range for phthalocyanines. The singlet oxygen quantum yield values increased drastically in the presence of gold nanoparticles. The photocatalytic products obtained from the reaction were cyclohexene oxide, 2-cyclohexen-1-ol, 2-cyclohexene-1-one and 1,4-cyclohexanediol. The percentage conversion values, yields and selectivity values improved significantly in the presence of AuNPs. Singlet oxygen was determined to be the main agent involved in the photocatalytic oxidation of cyclohexene. The electrocatalytic oxidation of bisphenol A and p-nitrophenol was carried out using nickel tetraamino phthalocyanine and all the newly synthesised metallophthalocyanine in the presence of gold nanoparticles and single walled carbon nanotubes. The charge transfer behaviour of AuNPs was enhanced in the presence of TaPc, TiPc and VPc complexes. The presence of single walled carbon nanotubes further improved electron transfer and minimised electrode passivation.
- Full Text:
- Date Issued: 2012
Electrospun nanofibers : an alternative sorbent material for solid phase extraction
- Chigome, Samuel, Samuel Chigome
- Authors: Chigome, Samuel , Samuel Chigome
- Date: 2012 , 2012-03-26
- Subjects: Nanofibers -- Research Electrospinning -- Research Sorbents -- Research Extraction (Chemistry) -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4314 , http://hdl.handle.net/10962/d1004972
- Description: The work described in the thesis seeks to lay a foundation for a better understanding of the use of electrospun nanofibers as a sorbent material. Three miniaturised electrospun nanofiber based solid phase extraction devices were fabricated. For the first two, 10 mg of electrospun polystyrene fibers were used as a sorbent bed for a micro column SPE device (8 mm bed height in a 200 μl pipette tip) and a disk (I) SPE device (5 mm 1 mm sorbent bed in a 1000 μl SPE barrel). While for the third, 4.6 mg of electrospun nylon nanofibers were used as a sorbent bed for a disk (II) SPE device, (sorbent bed consisting of 5 5 mm 350 μm stacked disks in a 500 μl SPE barrel). Corticosteroids were employed as model analytes for performance evaluation of the fabricated SPE devices. Quantitative recoveries (45.5-124.29 percent) were achieved for all SPE devices at a loading volume of 100 μl and analyte concentration of 500 ng ml-1. Three mathematical models; the Boltzmann, Weibull five parameter and the Sigmoid three parameter were employed to describe the break through profiles of each of the sorbent beds. The micro column SPE device exhibited a breakthrough volume of 1400 μl, and theoretical plates (7.98-9.1) while disk (I) SPE device exhibited 400-500 μl and 1.39-2.82 respectively. Disk (II) SPE device exhibited a breakthrough volume of 200 μl and theoretical plates 0.38-1.15. It was proposed that the formats of future electrospun nanofiber sorbent based SPE devices will be guided by mechanical strength of the polymer. The study classified electrospun polymer fibers into two as polystyrene type (relatively low mechanical strength) and nylon type (relatively high mechanical strength).
- Full Text:
- Date Issued: 2012
- Authors: Chigome, Samuel , Samuel Chigome
- Date: 2012 , 2012-03-26
- Subjects: Nanofibers -- Research Electrospinning -- Research Sorbents -- Research Extraction (Chemistry) -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4314 , http://hdl.handle.net/10962/d1004972
- Description: The work described in the thesis seeks to lay a foundation for a better understanding of the use of electrospun nanofibers as a sorbent material. Three miniaturised electrospun nanofiber based solid phase extraction devices were fabricated. For the first two, 10 mg of electrospun polystyrene fibers were used as a sorbent bed for a micro column SPE device (8 mm bed height in a 200 μl pipette tip) and a disk (I) SPE device (5 mm 1 mm sorbent bed in a 1000 μl SPE barrel). While for the third, 4.6 mg of electrospun nylon nanofibers were used as a sorbent bed for a disk (II) SPE device, (sorbent bed consisting of 5 5 mm 350 μm stacked disks in a 500 μl SPE barrel). Corticosteroids were employed as model analytes for performance evaluation of the fabricated SPE devices. Quantitative recoveries (45.5-124.29 percent) were achieved for all SPE devices at a loading volume of 100 μl and analyte concentration of 500 ng ml-1. Three mathematical models; the Boltzmann, Weibull five parameter and the Sigmoid three parameter were employed to describe the break through profiles of each of the sorbent beds. The micro column SPE device exhibited a breakthrough volume of 1400 μl, and theoretical plates (7.98-9.1) while disk (I) SPE device exhibited 400-500 μl and 1.39-2.82 respectively. Disk (II) SPE device exhibited a breakthrough volume of 200 μl and theoretical plates 0.38-1.15. It was proposed that the formats of future electrospun nanofiber sorbent based SPE devices will be guided by mechanical strength of the polymer. The study classified electrospun polymer fibers into two as polystyrene type (relatively low mechanical strength) and nylon type (relatively high mechanical strength).
- Full Text:
- Date Issued: 2012
Empirical modelling of the solar wind influence on Pc3 pulsation activity
- Authors: Lotz, Stefanus Ignatius
- Date: 2012
- Subjects: Solar wind -- Research Solar activity -- Research Stellar oscillations -- Research , Magnetospheric radio wave propagation , Interplanetary magnetic fields
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5464 , http://hdl.handle.net/10962/d1005249
- Description: Geomagnetic pulsations are ultra-low frequency (ULF) oscillations of the geomagnetic field that have been observed in the magnetosphere and on the Earth since the 1800’s. In the 1960’s in situ observations of the solar wind suggested that the source of pulsation activity must lie beyond the magnetosphere. In this work the influence of several solar wind plasma and interplanetary magnetic field (IMF) parameters on Pc3 pulsations are studied. Pc3 pulsations are a class of geomagnetic pulsations with frequency ranging between 22 and 100 mHz. A large dataset of solar wind and pulsation measurements is employed to develop two empirical models capable of predicting the Pc3 index (an indication of Pc3 intensity) at one hour and five minute time resolution, respectively. The models are based on artificial neural networks, due to their ability to model highly non-linear interactions between dependent and independent variables. A robust, iterative process is followed to find and rank the set of solar wind input parameters that optimally predict Pc3 activity. According to the parameter selection process the input parameters to the low resolution model (1 hour data) are, in order of importance, solar wind speed, a pair of time-based parameters, dynamic solar wind pressure, and the IMF orientation with respect to the Sun-Earth line (i.e. the cone angle). Input parameters to the high resolution model (5 minute data) are solar wind speed, cone angle, solar wind density and a pair of time-based parameters. Both models accurately predict Pc3 intensity from unseen solar wind data. It is observed that Pc3 activity ceases when the density in the solar wind is very low, even while other conditions are favourable for the generation and propagation of ULF waves. The influence that solar wind density has on Pc3 activity is studied by analysing six years of solar wind and Pc3 measurements at one minute resolution. It is suggested that the pause in Pc3 activity occurs due to two reasons: Firstly, the ULF waves that are generated in the region upstream of the bow shock does not grow efficiently if the solar wind density is very low; and secondly, waves that are generated cannot be convected into the magnetosphere because of the low Mach number of the solar wind plasma due to the decreased density.
- Full Text:
- Date Issued: 2012
- Authors: Lotz, Stefanus Ignatius
- Date: 2012
- Subjects: Solar wind -- Research Solar activity -- Research Stellar oscillations -- Research , Magnetospheric radio wave propagation , Interplanetary magnetic fields
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5464 , http://hdl.handle.net/10962/d1005249
- Description: Geomagnetic pulsations are ultra-low frequency (ULF) oscillations of the geomagnetic field that have been observed in the magnetosphere and on the Earth since the 1800’s. In the 1960’s in situ observations of the solar wind suggested that the source of pulsation activity must lie beyond the magnetosphere. In this work the influence of several solar wind plasma and interplanetary magnetic field (IMF) parameters on Pc3 pulsations are studied. Pc3 pulsations are a class of geomagnetic pulsations with frequency ranging between 22 and 100 mHz. A large dataset of solar wind and pulsation measurements is employed to develop two empirical models capable of predicting the Pc3 index (an indication of Pc3 intensity) at one hour and five minute time resolution, respectively. The models are based on artificial neural networks, due to their ability to model highly non-linear interactions between dependent and independent variables. A robust, iterative process is followed to find and rank the set of solar wind input parameters that optimally predict Pc3 activity. According to the parameter selection process the input parameters to the low resolution model (1 hour data) are, in order of importance, solar wind speed, a pair of time-based parameters, dynamic solar wind pressure, and the IMF orientation with respect to the Sun-Earth line (i.e. the cone angle). Input parameters to the high resolution model (5 minute data) are solar wind speed, cone angle, solar wind density and a pair of time-based parameters. Both models accurately predict Pc3 intensity from unseen solar wind data. It is observed that Pc3 activity ceases when the density in the solar wind is very low, even while other conditions are favourable for the generation and propagation of ULF waves. The influence that solar wind density has on Pc3 activity is studied by analysing six years of solar wind and Pc3 measurements at one minute resolution. It is suggested that the pause in Pc3 activity occurs due to two reasons: Firstly, the ULF waves that are generated in the region upstream of the bow shock does not grow efficiently if the solar wind density is very low; and secondly, waves that are generated cannot be convected into the magnetosphere because of the low Mach number of the solar wind plasma due to the decreased density.
- Full Text:
- Date Issued: 2012
Enhanced sensor-based interaction techniques for mobile map-based applications
- Authors: Van Tonder, Bradley Paul
- Date: 2012
- Subjects: Cartography , User interfaces (Computer systems) -- Design , Digital mapping
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10483 , http://hdl.handle.net/10948/d1012995
- Description: Mobile phones are increasingly being equipped with a wide range of sensors which enable a variety of interaction techniques. Sensor-based interaction techniques are particularly promising for domains such as map-based applications, where the user is required to interact with a large information space on the small screen of a mobile phone. Traditional interaction techniques have several shortcomings for interacting with mobile map-based applications. Keypad interaction offers limited control over panning speed and direction. Touch-screen interaction is often a two-handed form of interaction and results in the display being occluded during interaction. Sensor-based interaction provides the potential to address many of these shortcomings, but currently suffers from several limitations. The aim of this research was to propose enhancements to address the shortcomings of sensor-based interaction, with a particular focus on tilt interaction. A comparative study between tilt and keypad interaction was conducted using a prototype mobile map-based application. This user study was conducted in order to identify shortcomings and opportunities for improving tilt interaction techniques in this domain. Several shortcomings, including controllability, mental demand and practicality concerns were highlighted. Several enhanced tilt interaction techniques were proposed to address these shortcomings. These techniques were the use of visual and vibrotactile feedback, attractors, gesture zooming, sensitivity adaptation and dwell-time selection. The results of a comparative user study showed that the proposed techniques achieved several improvements in terms of the problem areas identified earlier. The use of sensor fusion for tilt interaction was compared to an accelerometer-only approach which has been widely applied in existing research. This evaluation was motivated by advances in mobile sensor technology which have led to the widespread adoption of digital compass and gyroscope sensors. The results of a comparative user study between sensor fusion and accelerometer-only implementations of tilt interaction showed several advantages for the use of sensor fusion, particularly in a walking context of use. Modifications to sensitivity adaptation and the use of tilt to perform zooming were also investigated. These modifications were designed to address controllability shortcomings identified in earlier experimental work. The results of a comparison between tilt zooming and Summary gesture zooming indicated that tilt zooming offered better results, both in terms of performance and subjective user ratings. Modifications to the original sensitivity adaptation algorithm were only partly successful. Greater accuracy improvements were achieved for walking tasks, but the use of dynamic dampening factors was found to be confusing. The results of this research were used to propose a framework for mobile tilt interaction. This framework provides an overview of the tilt interaction process and highlights how the enhanced techniques proposed in this research can be integrated into the design of tilt interaction techniques. The framework also proposes an application architecture which was implemented as an Application Programming Interface (API). This API was successfully used in the development of two prototype mobile applications incorporating tilt interaction.
- Full Text:
- Date Issued: 2012
- Authors: Van Tonder, Bradley Paul
- Date: 2012
- Subjects: Cartography , User interfaces (Computer systems) -- Design , Digital mapping
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10483 , http://hdl.handle.net/10948/d1012995
- Description: Mobile phones are increasingly being equipped with a wide range of sensors which enable a variety of interaction techniques. Sensor-based interaction techniques are particularly promising for domains such as map-based applications, where the user is required to interact with a large information space on the small screen of a mobile phone. Traditional interaction techniques have several shortcomings for interacting with mobile map-based applications. Keypad interaction offers limited control over panning speed and direction. Touch-screen interaction is often a two-handed form of interaction and results in the display being occluded during interaction. Sensor-based interaction provides the potential to address many of these shortcomings, but currently suffers from several limitations. The aim of this research was to propose enhancements to address the shortcomings of sensor-based interaction, with a particular focus on tilt interaction. A comparative study between tilt and keypad interaction was conducted using a prototype mobile map-based application. This user study was conducted in order to identify shortcomings and opportunities for improving tilt interaction techniques in this domain. Several shortcomings, including controllability, mental demand and practicality concerns were highlighted. Several enhanced tilt interaction techniques were proposed to address these shortcomings. These techniques were the use of visual and vibrotactile feedback, attractors, gesture zooming, sensitivity adaptation and dwell-time selection. The results of a comparative user study showed that the proposed techniques achieved several improvements in terms of the problem areas identified earlier. The use of sensor fusion for tilt interaction was compared to an accelerometer-only approach which has been widely applied in existing research. This evaluation was motivated by advances in mobile sensor technology which have led to the widespread adoption of digital compass and gyroscope sensors. The results of a comparative user study between sensor fusion and accelerometer-only implementations of tilt interaction showed several advantages for the use of sensor fusion, particularly in a walking context of use. Modifications to sensitivity adaptation and the use of tilt to perform zooming were also investigated. These modifications were designed to address controllability shortcomings identified in earlier experimental work. The results of a comparison between tilt zooming and Summary gesture zooming indicated that tilt zooming offered better results, both in terms of performance and subjective user ratings. Modifications to the original sensitivity adaptation algorithm were only partly successful. Greater accuracy improvements were achieved for walking tasks, but the use of dynamic dampening factors was found to be confusing. The results of this research were used to propose a framework for mobile tilt interaction. This framework provides an overview of the tilt interaction process and highlights how the enhanced techniques proposed in this research can be integrated into the design of tilt interaction techniques. The framework also proposes an application architecture which was implemented as an Application Programming Interface (API). This API was successfully used in the development of two prototype mobile applications incorporating tilt interaction.
- Full Text:
- Date Issued: 2012
Exploiting the adaptability of recent information and communication technology to improve the site management process
- Ozumba, Aghaegbuna Obinna Uche
- Authors: Ozumba, Aghaegbuna Obinna Uche
- Date: 2012
- Subjects: Construction industry -- Information technology , Construction industry -- Materials management , Information technology -- Management.
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9705 , http://hdl.handle.net/10948/d1019811
- Description: Construction is a big role player in every economy, and the Site Management Process (SMP) occupies a strategic position in the construction process. Despite existence of appreciable research, technology diffusion in the construction industry is slow. Information and Communication Technology (ICT) implementation processes and products have not adequately and beneficially exploited ICT for improvement of the SMP. This is especially true in developing countries. Without increase in utilisation of ICT, potential benefits for the SMP remain untapped. The aim of the thesis was to ascertain the levels of utilisation of recent ICT developments for the SMP, and thereby gauge the benefits or lack thereof. The theoretical concept of the research is based on the technology transfer sub-concept of adaptation. A fundamentally positivistic view, with principles of objectivist approach was used for the enquiry. The approach included an extensive literature review, and a multi-stage investigation strategy, set in South Africa. Theory reviewed was in the main disciplines of construction science and technology, computer science and technology, and management science. Investigations involved case studies of construction sites, a global ICT survey, a national practitioner survey, and analysis of ICT products. Findings from literature assert the appreciable potential utility in recent ICT, thereby substantiating the adaptability of recent ICT. In addition ICT adoption in the SMP is inadequate and inexpedient, falling short of potential benefits for construction, both generally and in the local context. Furthermore there are challenges to ICT adoption, which could vary according to context. Field research results also point to underutilisation of innovations located in recent ICT. The main challenges in this regard include inadequate knowledge of potential utility of recent ICT, and lack of relevant support and effective approaches to technology integration, in the SMP. Moreover exploitation of the adaptability of recent ICT in the local SMP does not go beyond basic adoption. As such most diffusion occurs only for items requiring an adaptation of usage context or area of application. The results strongly indicate minimal innovativeness in this regard. Frameworks for possible adaptations of existing technologies were also derived, while propositions are made for approaches to improve the utility of recent ICT in the SMP. Through a customised approach, the thesis establishes foundational understanding towards a generic framework for adapting potential utility in ICT to uses in construction, especially in the SMP. Thus the research contributes strategic information to the fledgling CICT body of knowledge, especially in the local context.
- Full Text:
- Date Issued: 2012
- Authors: Ozumba, Aghaegbuna Obinna Uche
- Date: 2012
- Subjects: Construction industry -- Information technology , Construction industry -- Materials management , Information technology -- Management.
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9705 , http://hdl.handle.net/10948/d1019811
- Description: Construction is a big role player in every economy, and the Site Management Process (SMP) occupies a strategic position in the construction process. Despite existence of appreciable research, technology diffusion in the construction industry is slow. Information and Communication Technology (ICT) implementation processes and products have not adequately and beneficially exploited ICT for improvement of the SMP. This is especially true in developing countries. Without increase in utilisation of ICT, potential benefits for the SMP remain untapped. The aim of the thesis was to ascertain the levels of utilisation of recent ICT developments for the SMP, and thereby gauge the benefits or lack thereof. The theoretical concept of the research is based on the technology transfer sub-concept of adaptation. A fundamentally positivistic view, with principles of objectivist approach was used for the enquiry. The approach included an extensive literature review, and a multi-stage investigation strategy, set in South Africa. Theory reviewed was in the main disciplines of construction science and technology, computer science and technology, and management science. Investigations involved case studies of construction sites, a global ICT survey, a national practitioner survey, and analysis of ICT products. Findings from literature assert the appreciable potential utility in recent ICT, thereby substantiating the adaptability of recent ICT. In addition ICT adoption in the SMP is inadequate and inexpedient, falling short of potential benefits for construction, both generally and in the local context. Furthermore there are challenges to ICT adoption, which could vary according to context. Field research results also point to underutilisation of innovations located in recent ICT. The main challenges in this regard include inadequate knowledge of potential utility of recent ICT, and lack of relevant support and effective approaches to technology integration, in the SMP. Moreover exploitation of the adaptability of recent ICT in the local SMP does not go beyond basic adoption. As such most diffusion occurs only for items requiring an adaptation of usage context or area of application. The results strongly indicate minimal innovativeness in this regard. Frameworks for possible adaptations of existing technologies were also derived, while propositions are made for approaches to improve the utility of recent ICT in the SMP. Through a customised approach, the thesis establishes foundational understanding towards a generic framework for adapting potential utility in ICT to uses in construction, especially in the SMP. Thus the research contributes strategic information to the fledgling CICT body of knowledge, especially in the local context.
- Full Text:
- Date Issued: 2012
Exploring the linkages between biodiversity conservation and ecotourism in protected areas
- Authors: Maciejewski, Kristine
- Date: 2012
- Subjects: Biodiversity conservation , Ecotourism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10709 , http://hdl.handle.net/10948/d1011033 , Biodiversity conservation , Ecotourism
- Description: The prospect of using ecotourism to add value to conservation initiatives has frequently been stated. However, there is a general lack of information on the costs and benefits of biodiversity and its management, and how this can be influenced by the ecotourism industry. This study seeks to explore the value of biodiversity from the perspective of ecotourism in a hierarchical series of studies that move from the biome-level perspective down to the value of juveniles in ecotourism. Ecotourism plays a significant role in the establishment and management of Private Protected Areas (PPAs) and hence the opportunity to be added to the conservation estate. The financial opportunity to be found in ‘big five’ areas had led to an uneven biome coverage of PPAs which has resulted in the over-representation of certain areas and a skewed contribution towards national conservation targets. The landscape-use of PPAs have indicated that ecotourism operators are largely driven to achieve successful game-viewing sightings which has influenced management and affected the landscape use of PPAs, the stocking rate of species, the introduction of extralimital species, and management of flagship species. These management decisions are based on anecdotal sources and have been made at the expense of biodiversity and therefore apparent conflict exists between ecotourism and conservation objectives. This is based on lack of information: ecotourism operators, despite the large area they protect, have not realised their potential to contribute to conservation. It is therefore important to develop policy and incentives to motivate the establishment of PPAs in areas of high conservation significance in order to contribute to national conservation targets. Ecotourism should be used as a solution to provide important insights into tourist preferences which contribute to the larger debate of how to establish a balance between managing animal populations to ensure tourist satisfaction while supporting conservation. To ensure sustainability of PPAs, it is strongly recommended to manage PPAs more intensively with regards to PPA size, species stocking rates and landscape use. The presence of juveniles at an animal sighting significantly contributes to tourist satisfaction which suggests that the loss of juveniles may reduce the attraction. This is used to provide recommendations that using contraception to control elephant population numbers should be applied with caution as a management tool as it may be counterproductive by negatively impacting ecotourism. The findings from this study not only contribute to the conservation of biodiversity through the use of ecotourism, but will also ensure sustainability of the ecotourism industry and build capacity for sustainable living.
- Full Text:
- Date Issued: 2012
- Authors: Maciejewski, Kristine
- Date: 2012
- Subjects: Biodiversity conservation , Ecotourism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10709 , http://hdl.handle.net/10948/d1011033 , Biodiversity conservation , Ecotourism
- Description: The prospect of using ecotourism to add value to conservation initiatives has frequently been stated. However, there is a general lack of information on the costs and benefits of biodiversity and its management, and how this can be influenced by the ecotourism industry. This study seeks to explore the value of biodiversity from the perspective of ecotourism in a hierarchical series of studies that move from the biome-level perspective down to the value of juveniles in ecotourism. Ecotourism plays a significant role in the establishment and management of Private Protected Areas (PPAs) and hence the opportunity to be added to the conservation estate. The financial opportunity to be found in ‘big five’ areas had led to an uneven biome coverage of PPAs which has resulted in the over-representation of certain areas and a skewed contribution towards national conservation targets. The landscape-use of PPAs have indicated that ecotourism operators are largely driven to achieve successful game-viewing sightings which has influenced management and affected the landscape use of PPAs, the stocking rate of species, the introduction of extralimital species, and management of flagship species. These management decisions are based on anecdotal sources and have been made at the expense of biodiversity and therefore apparent conflict exists between ecotourism and conservation objectives. This is based on lack of information: ecotourism operators, despite the large area they protect, have not realised their potential to contribute to conservation. It is therefore important to develop policy and incentives to motivate the establishment of PPAs in areas of high conservation significance in order to contribute to national conservation targets. Ecotourism should be used as a solution to provide important insights into tourist preferences which contribute to the larger debate of how to establish a balance between managing animal populations to ensure tourist satisfaction while supporting conservation. To ensure sustainability of PPAs, it is strongly recommended to manage PPAs more intensively with regards to PPA size, species stocking rates and landscape use. The presence of juveniles at an animal sighting significantly contributes to tourist satisfaction which suggests that the loss of juveniles may reduce the attraction. This is used to provide recommendations that using contraception to control elephant population numbers should be applied with caution as a management tool as it may be counterproductive by negatively impacting ecotourism. The findings from this study not only contribute to the conservation of biodiversity through the use of ecotourism, but will also ensure sustainability of the ecotourism industry and build capacity for sustainable living.
- Full Text:
- Date Issued: 2012
Exploring the use of folktales to enhance the resilince of children orphaned and rendered vulnerable
- Authors: Mayaba, Nokhanyo Nomakhwezi
- Date: 2012
- Subjects: Narrative therapy , Resilience (Personality trait) in children -- South Africa , Loss (Psychology) in children , Children of AIDS patients -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9513 , http://hdl.handle.net/10948/2776 , Narrative therapy , Resilience (Personality trait) in children -- South Africa , Loss (Psychology) in children , Children of AIDS patients -- South Africa
- Description: The recent increase in the number of children orphaned and rendered vulnerable by HIV and AIDS in South Africa has placed an added burden on schools as sites of care and support. Education policies mandate schools to develop strategies to support such children, but this is no easy task in contexts where teachers are already struggling to fulfill instructional requirements. Literature reveals that teachers in under-resourced schools, where the problem is more severely experienced regard this increased pastoral role as an added responsibility that they do not feel competent to execute. Since there is unlikely to be any significant improvement in the circumstances of these children in the near future, there is a need to discover creative ways to address this problem. I was led to ask how teachers could support children to better cope in the face of adversity in a way that could be easily integrated into the academic curriculum, so as to minimise the perceived burden of providing care and support. Based on my knowledge of the value of bibliotherapy in promoting resilient coping in individuals, I was interested to see if folktales could be used in a similar way with groups of children. Working from an asset-based perspective, and proceeding from a transformative and participatory epistemology, I adopted an action research design to explore the potential of traditional folktales to enhance positive coping responses in children orphaned and rendered vulnerable by HIV and AIDS. My choice of traditional folktales was influenced by the importance that resilience theory attaches to cultural variables in the resilience process. The participants were isiXhosa speaking children who were orphaned and rendered vulnerable by HIV and AIDS (OVC) between the ages of nine and fourteen years (n=30) in Cycle One who lived in a children‟s home or with foster parents. In Cycle Two, the study was conducted in a school setting with thirty (n=30) participants. I conducted two cycles of reflective action research enquiry to ascertain how folktales could be used to enable teachers to meet both pastoral and academic requirements. In the first cycle, I used a pre-post time series design to explore if merely telling the stories would enhance the resilience of the children. Although this use of the stories was teacher-centred, I knew that it would be an easy and time-saving way for teachers to provide support, if it proved to be effective in enhancing resilience. Drawings and accompanying explanations were used to generate data pre-and post-intervention. The thematic analysis of the data revealed that, post-intervention, there appeared to be an increase in two resilience-enhancing indicators: the children appeared to have a more positive sense of self and improved positive relations with peers/friends. Critical reflection on the process also revealed ethical and methodological concerns and problems when working with vulnerable children. The findings from this cycle informed my second cycle, in which I adopted a more participatory approach to engage the children in making meaning of the stories and explore how they related to their own lives. I used participatory arts based methods such as drawings, collages, drama and more usual qualitative strategies, such as focus group discussion and observation, to generate data. The findings from this cycle suggest that using such strategies will equip teachers with tools to enhance the resilience of OVC in a way that also promotes the attainment of instructional outcomes. This study has contributed important theoretical, methodological and pedagogical insights. Theoretically, this study has contributed to the social ecological perspective of resilience by confirming that cultural resources, such as indigenous African stories (folktales) can enhance the resilience of vulnerable children. Lessons learnt from this study had a methodological contribution to the ethics of working with children and the use of culturally appropriate resources in the field, which were folktales. This study has also contributed to the meaning making implications of using folktales, which can aid the pedagogical strategies that teachers use. Although this study was meant to be small- scale research and was not intended to be generalisable, the findings do suggest that teachers could have a resource that is time efficient, effective and could assist them to reach both their pastoral and academic goals.
- Full Text:
- Date Issued: 2012
Exploring the use of folktales to enhance the resilince of children orphaned and rendered vulnerable
- Authors: Mayaba, Nokhanyo Nomakhwezi
- Date: 2012
- Subjects: Narrative therapy , Resilience (Personality trait) in children -- South Africa , Loss (Psychology) in children , Children of AIDS patients -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9513 , http://hdl.handle.net/10948/2776 , Narrative therapy , Resilience (Personality trait) in children -- South Africa , Loss (Psychology) in children , Children of AIDS patients -- South Africa
- Description: The recent increase in the number of children orphaned and rendered vulnerable by HIV and AIDS in South Africa has placed an added burden on schools as sites of care and support. Education policies mandate schools to develop strategies to support such children, but this is no easy task in contexts where teachers are already struggling to fulfill instructional requirements. Literature reveals that teachers in under-resourced schools, where the problem is more severely experienced regard this increased pastoral role as an added responsibility that they do not feel competent to execute. Since there is unlikely to be any significant improvement in the circumstances of these children in the near future, there is a need to discover creative ways to address this problem. I was led to ask how teachers could support children to better cope in the face of adversity in a way that could be easily integrated into the academic curriculum, so as to minimise the perceived burden of providing care and support. Based on my knowledge of the value of bibliotherapy in promoting resilient coping in individuals, I was interested to see if folktales could be used in a similar way with groups of children. Working from an asset-based perspective, and proceeding from a transformative and participatory epistemology, I adopted an action research design to explore the potential of traditional folktales to enhance positive coping responses in children orphaned and rendered vulnerable by HIV and AIDS. My choice of traditional folktales was influenced by the importance that resilience theory attaches to cultural variables in the resilience process. The participants were isiXhosa speaking children who were orphaned and rendered vulnerable by HIV and AIDS (OVC) between the ages of nine and fourteen years (n=30) in Cycle One who lived in a children‟s home or with foster parents. In Cycle Two, the study was conducted in a school setting with thirty (n=30) participants. I conducted two cycles of reflective action research enquiry to ascertain how folktales could be used to enable teachers to meet both pastoral and academic requirements. In the first cycle, I used a pre-post time series design to explore if merely telling the stories would enhance the resilience of the children. Although this use of the stories was teacher-centred, I knew that it would be an easy and time-saving way for teachers to provide support, if it proved to be effective in enhancing resilience. Drawings and accompanying explanations were used to generate data pre-and post-intervention. The thematic analysis of the data revealed that, post-intervention, there appeared to be an increase in two resilience-enhancing indicators: the children appeared to have a more positive sense of self and improved positive relations with peers/friends. Critical reflection on the process also revealed ethical and methodological concerns and problems when working with vulnerable children. The findings from this cycle informed my second cycle, in which I adopted a more participatory approach to engage the children in making meaning of the stories and explore how they related to their own lives. I used participatory arts based methods such as drawings, collages, drama and more usual qualitative strategies, such as focus group discussion and observation, to generate data. The findings from this cycle suggest that using such strategies will equip teachers with tools to enhance the resilience of OVC in a way that also promotes the attainment of instructional outcomes. This study has contributed important theoretical, methodological and pedagogical insights. Theoretically, this study has contributed to the social ecological perspective of resilience by confirming that cultural resources, such as indigenous African stories (folktales) can enhance the resilience of vulnerable children. Lessons learnt from this study had a methodological contribution to the ethics of working with children and the use of culturally appropriate resources in the field, which were folktales. This study has also contributed to the meaning making implications of using folktales, which can aid the pedagogical strategies that teachers use. Although this study was meant to be small- scale research and was not intended to be generalisable, the findings do suggest that teachers could have a resource that is time efficient, effective and could assist them to reach both their pastoral and academic goals.
- Full Text:
- Date Issued: 2012
Factors affecting the implementation of the National Curriculum Statement in the Mthatha education district
- Gobingca, Berington Zanoxolo
- Authors: Gobingca, Berington Zanoxolo
- Date: 2012
- Subjects: Curriculum planning -- South Africa -- Eastern Cape , Curriculum change -- South Africa , Education -- South Africa -- Curricula
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9442
- Description: The current investigation was conducted in the Mthatha Education District. It sought to investigate factors affecting the implementation of the National Curriculum Statement (NCS) in the Mthatha schools of the Eastern Cape Province in South Africa. Literature reviewed showed that teachers, as the key role players to the implementation of the curriculum in schools, are still experiencing difficulties in implementing the NCS. It is thus important to establish and investigate the factors affecting the implementation of the NCS. The research was both exploratory and explanatory in nature and adopted a mixed method approach. Questionnaires were distributed among 210 teachers who were randomly selected from 363 schools in the Mthatha Education District. Out of 210 teachers who were provided with questionnaires to fill out, it was 148 (70.5 percent) of them who completed and returned the questionnaires. Semi-structured interviews were conducted face-to-face with 10 purposefully selected teachers to collect the data from those who participated by filling out the questionnaires. The researcher analysed the data both quantitatively and qualitatively. The data was presented, analysed and discussed according to themes derived from the main research question and sub-questions. The quantitative data (closed-ended statements) was analysed statistically by means of the Statistical Package for Social Sciences (SPSS). In the case of the qualitative data (open-ended statements in questionnaires and interviews), similar responses were analysed in themes as per the research question and sub-questions for easy interpretation. Note-taking and tape-recording were done during the interview sessions. Qualitative data were transcribed, coded and analysed. The findings which emerged from the study indicated that intermediate-phase teachers experienced difficulties in implementing the NCS. These were attributed to, amongst others, a lack of resources such as learning material and infrastructure, redeployment of teachers, a high learner teacher ratio, inadequate in-service training and support from the DoE. These factors need to be addressed to enhance the implementation of the NCS and to avoid the repetition of those shortcomings in any future envisaged changes to the curriculum such as the implementation of CAPS.
- Full Text:
- Date Issued: 2012
- Authors: Gobingca, Berington Zanoxolo
- Date: 2012
- Subjects: Curriculum planning -- South Africa -- Eastern Cape , Curriculum change -- South Africa , Education -- South Africa -- Curricula
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9442
- Description: The current investigation was conducted in the Mthatha Education District. It sought to investigate factors affecting the implementation of the National Curriculum Statement (NCS) in the Mthatha schools of the Eastern Cape Province in South Africa. Literature reviewed showed that teachers, as the key role players to the implementation of the curriculum in schools, are still experiencing difficulties in implementing the NCS. It is thus important to establish and investigate the factors affecting the implementation of the NCS. The research was both exploratory and explanatory in nature and adopted a mixed method approach. Questionnaires were distributed among 210 teachers who were randomly selected from 363 schools in the Mthatha Education District. Out of 210 teachers who were provided with questionnaires to fill out, it was 148 (70.5 percent) of them who completed and returned the questionnaires. Semi-structured interviews were conducted face-to-face with 10 purposefully selected teachers to collect the data from those who participated by filling out the questionnaires. The researcher analysed the data both quantitatively and qualitatively. The data was presented, analysed and discussed according to themes derived from the main research question and sub-questions. The quantitative data (closed-ended statements) was analysed statistically by means of the Statistical Package for Social Sciences (SPSS). In the case of the qualitative data (open-ended statements in questionnaires and interviews), similar responses were analysed in themes as per the research question and sub-questions for easy interpretation. Note-taking and tape-recording were done during the interview sessions. Qualitative data were transcribed, coded and analysed. The findings which emerged from the study indicated that intermediate-phase teachers experienced difficulties in implementing the NCS. These were attributed to, amongst others, a lack of resources such as learning material and infrastructure, redeployment of teachers, a high learner teacher ratio, inadequate in-service training and support from the DoE. These factors need to be addressed to enhance the implementation of the NCS and to avoid the repetition of those shortcomings in any future envisaged changes to the curriculum such as the implementation of CAPS.
- Full Text:
- Date Issued: 2012
Farm level institutions in emergent communities in post fast track Zimbabwe: case of Mazowe district
- Authors: Chiweshe, Manase Kudzai
- Date: 2012
- Subjects: Land reform -- Zimbabwe -- History -- 21st century Land settlement -- Social aspects -- Zimbabwe Zimbabwe -- Social conditions -- 1980- Zimbabwe -- Economic conditions Zimbabwe -- Politics and government -- 1980-
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3308 , http://hdl.handle.net/10962/d1003096
- Description: The thesis seeks to understand how emerging communities borne out of the Fast Track Land Reform Programme in Zimbabwe have been able to ensure social cohesion and social service provision using farm level institutions. The Fast Track Programme brought together people from diverse backgrounds into new communities in the former commercial farming areas. The formation of new communities meant that, often, there were 'stranger households'living next to each other. Since 2000, these people have been involved in various processes aimed at turning clusters of homesteads into functioning communities through farm level institutions. Fast track land reform precipitated economic and political crisis in Zimbabwe characterised by a rapidly devaluating Zimbabwean dollar, enormous inflation and high unemployment figures. This economic crisis has impacted heavily on new farmers who find it increasingly difficult to afford inputs and access loans. They have formed social networks in response to these challenges, taking the form of farm level institutions such as farm committees, irrigation committees and health committees. The study uses case studies from small-scale 'A1 farmers‘ in Mazowe district which is in Mashonaland Central Province. It employs qualitative methodologies to enable a nuanced understanding of associational life in the new communities. Through focus group discussions, in-depth interviews, narratives, key informant interviews and institutional mapping the study outlines the formation, taxonomy, activities, roles, internal dynamics and social organisation of farm level institutions. The study also uses secondary data collected in 2007-08 by the Centre for Rural Development in the newly resettled areas in Mazowe. The major finding of the study is that farmers are organising in novel ways at grassroots levels to meet everyday challenges. These institutional forms however are internally weak, lacking leadership with a clear vision and they appear as if they are transitory in nature. They remain marginalised from national and global processes and isolated from critical connections to policy makers at all levels; thus A1 farmers remain voiceless and unable to have their interests addressed. Farm level institutions are at the forefront of the microeconomics of survival among these rural farmers. They are survivalist in nature and form, and this requires a major shift in focus if they are to be involved in developmental work. The institutions remain fragmented and compete amongst themselves for services from government without uniting as A1 farmers with similar interests and challenges.
- Full Text:
- Date Issued: 2012
Farm level institutions in emergent communities in post fast track Zimbabwe: case of Mazowe district
- Authors: Chiweshe, Manase Kudzai
- Date: 2012
- Subjects: Land reform -- Zimbabwe -- History -- 21st century Land settlement -- Social aspects -- Zimbabwe Zimbabwe -- Social conditions -- 1980- Zimbabwe -- Economic conditions Zimbabwe -- Politics and government -- 1980-
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3308 , http://hdl.handle.net/10962/d1003096
- Description: The thesis seeks to understand how emerging communities borne out of the Fast Track Land Reform Programme in Zimbabwe have been able to ensure social cohesion and social service provision using farm level institutions. The Fast Track Programme brought together people from diverse backgrounds into new communities in the former commercial farming areas. The formation of new communities meant that, often, there were 'stranger households'living next to each other. Since 2000, these people have been involved in various processes aimed at turning clusters of homesteads into functioning communities through farm level institutions. Fast track land reform precipitated economic and political crisis in Zimbabwe characterised by a rapidly devaluating Zimbabwean dollar, enormous inflation and high unemployment figures. This economic crisis has impacted heavily on new farmers who find it increasingly difficult to afford inputs and access loans. They have formed social networks in response to these challenges, taking the form of farm level institutions such as farm committees, irrigation committees and health committees. The study uses case studies from small-scale 'A1 farmers‘ in Mazowe district which is in Mashonaland Central Province. It employs qualitative methodologies to enable a nuanced understanding of associational life in the new communities. Through focus group discussions, in-depth interviews, narratives, key informant interviews and institutional mapping the study outlines the formation, taxonomy, activities, roles, internal dynamics and social organisation of farm level institutions. The study also uses secondary data collected in 2007-08 by the Centre for Rural Development in the newly resettled areas in Mazowe. The major finding of the study is that farmers are organising in novel ways at grassroots levels to meet everyday challenges. These institutional forms however are internally weak, lacking leadership with a clear vision and they appear as if they are transitory in nature. They remain marginalised from national and global processes and isolated from critical connections to policy makers at all levels; thus A1 farmers remain voiceless and unable to have their interests addressed. Farm level institutions are at the forefront of the microeconomics of survival among these rural farmers. They are survivalist in nature and form, and this requires a major shift in focus if they are to be involved in developmental work. The institutions remain fragmented and compete amongst themselves for services from government without uniting as A1 farmers with similar interests and challenges.
- Full Text:
- Date Issued: 2012
Fire regimes in eastern coastal fynbos: drivers, ecology and management
- Authors: Kraaij, Tineke
- Date: 2012
- Subjects: Forest fires -- South Africa , Climatic changes , Prescribed burning , Fire ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10607 , http://hdl.handle.net/10948/d1008047 , Forest fires -- South Africa , Climatic changes , Prescribed burning , Fire ecology -- South Africa
- Description: Conventional knowledge of fynbos fire ecology is based on the summer-autumn fire regimes of the western Cape Floral Kingdom (CFK) where the climate is Mediterranean. However, the climate in the eastern coastal-CFK is milder and rainfall occurs year-round, with presumed effects on fire regimes. The Garden Route National Park (GRNP) has recently been established in the region, in a landscape where indigenous forests, fire-prone fynbos shrublands and fire-sensitive plantations of invasive alien trees are interspersed. The park faces considerable challenges related to the management of fire, including significant pressure from the adjacent plantation industry to reduce wildfire hazard by burning fynbos at short intervals, and high levels of invasion by alien trees (largely Pinus species originating from plantations). This study sought to improve understanding of fire regimes in eastern coastal fynbos shrublands, and to provide guidelines for ecologically sound management of fire in the area. My approach entailed (i) an assessment of the context within which fire management was practiced during the past century; (ii) characterisation of the recent fire history and fire regime (1900–2010); (iii) characterisation of the seasonality of fire weather and lightning; (iv) estimation of minimum fire return intervals (FRIs) from juvenile periods and post-fire recruitment success of overstorey proteoids (non-sprouting, slow-maturing, serotinous Proteaceae); and (v) determination of the ecologically appropriate fire season from post-fire recruitment seasonality of proteoids. I established that historically, plantation protection enjoyed priority over fynbos conservation in the area that is now the GRNP. Fynbos close to plantations has most likely been compromised by frequent and low-intensity burning in the past, as well as by invasion by alien trees. In terms of area burnt (1900–2010), natural (lightning-ignited) fires dominated the fire regime, particularly in the east, whereas prescribed burning was relatively unimportant. Typical fire return intervals (FRIs; 8–26 years; 1980–2010) were comparable to those in other fynbos protected areas and appeared to be shorter in the eastern Tsitsikamma than in the western Outeniqua halves of the study area. Proteaceae juvenile periods (4–9 years) and post-fire recruitment success (following fires in ≥7 year-old vegetation) suggested that for biodiversity conservation purposes, FRIs should be no less than nine years in moist, productive fynbos. Increases in the total area burnt annually (since 1980) were correlated with long-term increases in average fire danger weather, suggesting that fire regime changes may be related to global change. Collectively, findings on the seasonality of actual fires and the seasonality of fire danger weather, lightning, and post-fire proteoid recruitment suggested that fires in eastern coastal fynbos are not limited to any particular season, and for this reason managers do not need to be concerned if fires occur in any season. The ecological requirements for higher fire intensity may nonetheless be constrained by a need for safety. I articulated these findings into ecological thresholds pertaining to the different elements of the fire regime in eastern coastal fynbos, to guide adaptive management of fire in the Garden Route National Park. I also recommended a fire management strategy for the park to address the aforementioned operational considerations within the constraints posed by ecological thresholds. Finally, I highlighted further research and monitoring needs.
- Full Text:
- Date Issued: 2012
- Authors: Kraaij, Tineke
- Date: 2012
- Subjects: Forest fires -- South Africa , Climatic changes , Prescribed burning , Fire ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10607 , http://hdl.handle.net/10948/d1008047 , Forest fires -- South Africa , Climatic changes , Prescribed burning , Fire ecology -- South Africa
- Description: Conventional knowledge of fynbos fire ecology is based on the summer-autumn fire regimes of the western Cape Floral Kingdom (CFK) where the climate is Mediterranean. However, the climate in the eastern coastal-CFK is milder and rainfall occurs year-round, with presumed effects on fire regimes. The Garden Route National Park (GRNP) has recently been established in the region, in a landscape where indigenous forests, fire-prone fynbos shrublands and fire-sensitive plantations of invasive alien trees are interspersed. The park faces considerable challenges related to the management of fire, including significant pressure from the adjacent plantation industry to reduce wildfire hazard by burning fynbos at short intervals, and high levels of invasion by alien trees (largely Pinus species originating from plantations). This study sought to improve understanding of fire regimes in eastern coastal fynbos shrublands, and to provide guidelines for ecologically sound management of fire in the area. My approach entailed (i) an assessment of the context within which fire management was practiced during the past century; (ii) characterisation of the recent fire history and fire regime (1900–2010); (iii) characterisation of the seasonality of fire weather and lightning; (iv) estimation of minimum fire return intervals (FRIs) from juvenile periods and post-fire recruitment success of overstorey proteoids (non-sprouting, slow-maturing, serotinous Proteaceae); and (v) determination of the ecologically appropriate fire season from post-fire recruitment seasonality of proteoids. I established that historically, plantation protection enjoyed priority over fynbos conservation in the area that is now the GRNP. Fynbos close to plantations has most likely been compromised by frequent and low-intensity burning in the past, as well as by invasion by alien trees. In terms of area burnt (1900–2010), natural (lightning-ignited) fires dominated the fire regime, particularly in the east, whereas prescribed burning was relatively unimportant. Typical fire return intervals (FRIs; 8–26 years; 1980–2010) were comparable to those in other fynbos protected areas and appeared to be shorter in the eastern Tsitsikamma than in the western Outeniqua halves of the study area. Proteaceae juvenile periods (4–9 years) and post-fire recruitment success (following fires in ≥7 year-old vegetation) suggested that for biodiversity conservation purposes, FRIs should be no less than nine years in moist, productive fynbos. Increases in the total area burnt annually (since 1980) were correlated with long-term increases in average fire danger weather, suggesting that fire regime changes may be related to global change. Collectively, findings on the seasonality of actual fires and the seasonality of fire danger weather, lightning, and post-fire proteoid recruitment suggested that fires in eastern coastal fynbos are not limited to any particular season, and for this reason managers do not need to be concerned if fires occur in any season. The ecological requirements for higher fire intensity may nonetheless be constrained by a need for safety. I articulated these findings into ecological thresholds pertaining to the different elements of the fire regime in eastern coastal fynbos, to guide adaptive management of fire in the Garden Route National Park. I also recommended a fire management strategy for the park to address the aforementioned operational considerations within the constraints posed by ecological thresholds. Finally, I highlighted further research and monitoring needs.
- Full Text:
- Date Issued: 2012