A contribution to the theory of prime modules
- Authors: Ssevviiri, David
- Date: 2013
- Subjects: Modules (Algebra) , Radical theory , Rings (Algebra)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10510 , http://hdl.handle.net/10948/d1019923
- Description: This thesis is aimed at generalizing notions of rings to modules. In par-ticular, notions of completely prime ideals, s-prime ideals, 2-primal rings and nilpotency of elements of rings are respectively generalized to completely prime submodules and classical completely prime submodules, s-prime submodules, 2-primal modules and nilpotency of elements of modules. Properties and rad-icals that arise from each of these notions are studied.
- Full Text:
- Date Issued: 2013
- Authors: Ssevviiri, David
- Date: 2013
- Subjects: Modules (Algebra) , Radical theory , Rings (Algebra)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10510 , http://hdl.handle.net/10948/d1019923
- Description: This thesis is aimed at generalizing notions of rings to modules. In par-ticular, notions of completely prime ideals, s-prime ideals, 2-primal rings and nilpotency of elements of rings are respectively generalized to completely prime submodules and classical completely prime submodules, s-prime submodules, 2-primal modules and nilpotency of elements of modules. Properties and rad-icals that arise from each of these notions are studied.
- Full Text:
- Date Issued: 2013
A framework for assuring conformance of cloud-based email at higher education institutions
- Authors: Willett, Melanie
- Date: 2013
- Subjects: Cloud computing -- Security measures , Computer networks -- Security measures , Web services , Education, Higher -- Technological innovations
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9815 , http://hdl.handle.net/10948/d1018664
- Description: Cloud computing is a relatively immature computing paradigm that could significantly benefit users. Cloud computing solutions are often associated with potential benefits such as cost reduction, less administrative hassle, flexibility and scalability. For organisations to realize such potential benefits, cloud computing solutions need to be chosen, implemented, managed and governed in a way that is secure, compliant with internal and external requirements and indicative of due diligence. This can be a challenge, given the many concerns and risks commonly associated with cloud computing solutions. One cloud computing solution that is being widely adopted around the world is cloud-based email. One of the foremost adopters of this cloud computing solution is higher education institutions. These higher education institutions stand to benefit greatly from using such services. Cloud-based email can be provisioned to staff and students at these institutions for free. Additionally, cloud service providers (CSPs) are able to provide a better email service than some higher education institutions would be able to provide if they were required to do so in-house. CSPs often provide larger inboxes and many extra services with cloud-based email. Cloud-based email is, therefore, clearly an example of a cloud computing solution that has the potential to benefit organisations. There are however, risks and challenges associated with the use of this cloud computing solution. Two of these challenges relate to ensuring conformance to internal and external (legal, regulatory and contractual obligations) requirements and to providing a mechanism of assuring that cloud-based email related activities are sound. The lack of structured guidelines for assuring the conformance of cloud-based email is putting this service at risk at higher education institutions in South Africa. This work addresses this problem by promoting a best practice based approach to assuring the conformance of cloud-based email at higher education institutions. To accomplish this, components of applicable standards and best practice guidelines for IT governance, IT assurance and IT conformance are used to construct a framework for assuring the conformance of cloud-based email. The framework is designed and verified using sound design science principles. The utility and value of the framework has been demonstrated at a higher education institution in South Africa. This framework can be used to assist higher education institutions to demonstrate due diligence in assuring that they conform to legal and best practice requirements for the management and governance of cloud-based email. This is a significant contribution in the relatively new field of cloud computing governance.
- Full Text:
- Date Issued: 2013
- Authors: Willett, Melanie
- Date: 2013
- Subjects: Cloud computing -- Security measures , Computer networks -- Security measures , Web services , Education, Higher -- Technological innovations
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9815 , http://hdl.handle.net/10948/d1018664
- Description: Cloud computing is a relatively immature computing paradigm that could significantly benefit users. Cloud computing solutions are often associated with potential benefits such as cost reduction, less administrative hassle, flexibility and scalability. For organisations to realize such potential benefits, cloud computing solutions need to be chosen, implemented, managed and governed in a way that is secure, compliant with internal and external requirements and indicative of due diligence. This can be a challenge, given the many concerns and risks commonly associated with cloud computing solutions. One cloud computing solution that is being widely adopted around the world is cloud-based email. One of the foremost adopters of this cloud computing solution is higher education institutions. These higher education institutions stand to benefit greatly from using such services. Cloud-based email can be provisioned to staff and students at these institutions for free. Additionally, cloud service providers (CSPs) are able to provide a better email service than some higher education institutions would be able to provide if they were required to do so in-house. CSPs often provide larger inboxes and many extra services with cloud-based email. Cloud-based email is, therefore, clearly an example of a cloud computing solution that has the potential to benefit organisations. There are however, risks and challenges associated with the use of this cloud computing solution. Two of these challenges relate to ensuring conformance to internal and external (legal, regulatory and contractual obligations) requirements and to providing a mechanism of assuring that cloud-based email related activities are sound. The lack of structured guidelines for assuring the conformance of cloud-based email is putting this service at risk at higher education institutions in South Africa. This work addresses this problem by promoting a best practice based approach to assuring the conformance of cloud-based email at higher education institutions. To accomplish this, components of applicable standards and best practice guidelines for IT governance, IT assurance and IT conformance are used to construct a framework for assuring the conformance of cloud-based email. The framework is designed and verified using sound design science principles. The utility and value of the framework has been demonstrated at a higher education institution in South Africa. This framework can be used to assist higher education institutions to demonstrate due diligence in assuring that they conform to legal and best practice requirements for the management and governance of cloud-based email. This is a significant contribution in the relatively new field of cloud computing governance.
- Full Text:
- Date Issued: 2013
A framework for biometrics for social grants in South Africa
- Authors: Van de Haar, Helen Augusta
- Date: 2013
- Subjects: Biometric identification -- Law and legislation -- South Africa , Biometric identification cards -- South Africa , Public welfare -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9829 , http://hdl.handle.net/10948/d1021018
- Description: In the South African Social Security Agency (SASSA) Annual Report of 2011/2012 it is stated that there were more than 15 million social grants paid out to needy beneficiaries of which 10 927 731 were Child Support Grants. A major challenge that is continually being addressed is the management and administration of these grants. In particular, the focus is on service delivery and zero tolerance to fraud and corruption. SASSA has made various attempts to address these issues, such as the rollout of biometric smart cards in 2012. This research endeavour attempts to discover whether a framework can be designed where necessary factors are taken into consideration to provide for an efficient social grant application and delivery process that uses biometrics. The framework aims to suggest improvements in the use of biometrics for the social grants. Seeing that biometrics in this case is used as a technology to improve a system involving humans, this study followed a Design Science approach and made use of a case study to collect the data required for the study. Literature studies reviewed the fields of social grants and biometrics. The challenges and lessons learnt from current implementations of social grants and biometrics within the South African context and further abroad were also relevant for the study. The framework that resulted from the above was evaluated for validity and applicability after which a modified framework is presented. The research concludes with specific implementation guidelines as well as areas for future research.
- Full Text:
- Date Issued: 2013
- Authors: Van de Haar, Helen Augusta
- Date: 2013
- Subjects: Biometric identification -- Law and legislation -- South Africa , Biometric identification cards -- South Africa , Public welfare -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9829 , http://hdl.handle.net/10948/d1021018
- Description: In the South African Social Security Agency (SASSA) Annual Report of 2011/2012 it is stated that there were more than 15 million social grants paid out to needy beneficiaries of which 10 927 731 were Child Support Grants. A major challenge that is continually being addressed is the management and administration of these grants. In particular, the focus is on service delivery and zero tolerance to fraud and corruption. SASSA has made various attempts to address these issues, such as the rollout of biometric smart cards in 2012. This research endeavour attempts to discover whether a framework can be designed where necessary factors are taken into consideration to provide for an efficient social grant application and delivery process that uses biometrics. The framework aims to suggest improvements in the use of biometrics for the social grants. Seeing that biometrics in this case is used as a technology to improve a system involving humans, this study followed a Design Science approach and made use of a case study to collect the data required for the study. Literature studies reviewed the fields of social grants and biometrics. The challenges and lessons learnt from current implementations of social grants and biometrics within the South African context and further abroad were also relevant for the study. The framework that resulted from the above was evaluated for validity and applicability after which a modified framework is presented. The research concludes with specific implementation guidelines as well as areas for future research.
- Full Text:
- Date Issued: 2013
A model for managing user experience
- Authors: Mashapa, Job
- Date: 2013
- Subjects: Technological innovations -- Management , User interfaces (Computer systems)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9826 , http://hdl.handle.net/10948/d1020765
- Description: New innovative products are being designed while the user interface of existing products is constantly being revamped to give them a new look. All this is an effort to bring a satisfactory interacting experience for the user. However, in most cases users do not feel that they experience that benefit. The introduction of a new product, or the enhancement of the functionality and user interface of an existing product, often faces criticism and brings resistance to the acceptance and usage of the product by the users. Therefore, the change in user interface or introduction of new products does not only affect the business processes but also the lifestyles of the users, as well as their overall user experience. One of the most important components for the success of any product is a positive user experience. User experience refers to the subjective feeling of the user that results from their interaction or intention to interact with a product in order to perform a specific task in a specific environment. When the user interface and functionality of a product match the expectations of the users and make the users effective and efficient, feel safe and attain some level of self-worth from using or possessing the product, their interaction with the product becomes more satisfactory. User experience practitioners are in agreement that a change to the user interface influences the user experience of the people when interacting with the product; hence it affects change in the user experience of the people. A vast body of literature exists on the methods for evaluating user experience as well as on the principles that are aimed at guiding the design of products for a positive user experience. However, there is a lack of a means to manage this change in user experience that results from the changes in the features of the user interface or the product functionalities. This inadequacy opens up the potential for integrating change management principles in order to manage user experience. However, existing change management principles do not address the user experience aspects when managing change. Following the above premise, this study focused on the development of a model for managing user experience: the User Experience Management Model (UXM2). The UXM2 infers its components from the disciplines of user experience and change management. Its uniqueness is seated in its people-centred approach that aims to effect a free-will change in the individuals towards a long-term positive user experience. The proposed model further aims to promote the voluntary acceptance of a product, which is contrary to the mandatory change that is guided by the policies of the organization, as discussed in the study. The UXM2 was developed from a thorough argumentation of literature on user experience and change management. The components that were required for development of the model were identified from literature, and were evaluated for their relevance by means of academic publications in subject domain international conferences. The academic publications underwent double-blind peer review with subject domain experts. The model was evaluated for its relevance and potential applicability through interviews and discussions with subject domain experts. The subject domain experts consist of user experience practitioners and academic professionals in the domain of HCI. The subject domain experts also evaluated the model by means of an evaluation tool comprising of a Likert scale rating of the proposed components and related activities for managing user experience. The target users of the UXM2 are user experience practitioners and product developers who aim to promote a sustainable long-term positive user experience for the people interacting with their products. The UXM2 is aimed at being used for the design of products that are meant for institutional use, personal use, mandatory use and optional use. It is believed that adoption of the UXM2 will promote acceptance of the product by users, with an associated sustainable positive long-term user experience.
- Full Text:
- Date Issued: 2013
- Authors: Mashapa, Job
- Date: 2013
- Subjects: Technological innovations -- Management , User interfaces (Computer systems)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9826 , http://hdl.handle.net/10948/d1020765
- Description: New innovative products are being designed while the user interface of existing products is constantly being revamped to give them a new look. All this is an effort to bring a satisfactory interacting experience for the user. However, in most cases users do not feel that they experience that benefit. The introduction of a new product, or the enhancement of the functionality and user interface of an existing product, often faces criticism and brings resistance to the acceptance and usage of the product by the users. Therefore, the change in user interface or introduction of new products does not only affect the business processes but also the lifestyles of the users, as well as their overall user experience. One of the most important components for the success of any product is a positive user experience. User experience refers to the subjective feeling of the user that results from their interaction or intention to interact with a product in order to perform a specific task in a specific environment. When the user interface and functionality of a product match the expectations of the users and make the users effective and efficient, feel safe and attain some level of self-worth from using or possessing the product, their interaction with the product becomes more satisfactory. User experience practitioners are in agreement that a change to the user interface influences the user experience of the people when interacting with the product; hence it affects change in the user experience of the people. A vast body of literature exists on the methods for evaluating user experience as well as on the principles that are aimed at guiding the design of products for a positive user experience. However, there is a lack of a means to manage this change in user experience that results from the changes in the features of the user interface or the product functionalities. This inadequacy opens up the potential for integrating change management principles in order to manage user experience. However, existing change management principles do not address the user experience aspects when managing change. Following the above premise, this study focused on the development of a model for managing user experience: the User Experience Management Model (UXM2). The UXM2 infers its components from the disciplines of user experience and change management. Its uniqueness is seated in its people-centred approach that aims to effect a free-will change in the individuals towards a long-term positive user experience. The proposed model further aims to promote the voluntary acceptance of a product, which is contrary to the mandatory change that is guided by the policies of the organization, as discussed in the study. The UXM2 was developed from a thorough argumentation of literature on user experience and change management. The components that were required for development of the model were identified from literature, and were evaluated for their relevance by means of academic publications in subject domain international conferences. The academic publications underwent double-blind peer review with subject domain experts. The model was evaluated for its relevance and potential applicability through interviews and discussions with subject domain experts. The subject domain experts consist of user experience practitioners and academic professionals in the domain of HCI. The subject domain experts also evaluated the model by means of an evaluation tool comprising of a Likert scale rating of the proposed components and related activities for managing user experience. The target users of the UXM2 are user experience practitioners and product developers who aim to promote a sustainable long-term positive user experience for the people interacting with their products. The UXM2 is aimed at being used for the design of products that are meant for institutional use, personal use, mandatory use and optional use. It is believed that adoption of the UXM2 will promote acceptance of the product by users, with an associated sustainable positive long-term user experience.
- Full Text:
- Date Issued: 2013
A value framework for information and communication technology governance in South African higher education institutions
- Authors: Johl, Christian Peter
- Date: 2013
- Subjects: Information technology -- South Africa -- Management , Universities and colleges -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9821 , http://hdl.handle.net/10948/d1020281
- Description: The public higher education sector in South Africa is governed by an act of Parliament which defines the governance organs and mechanisms required within institutions and the sector. This doctoral thesis begins by contextualising ICT governance within the levels of systemic governance in South Africa that have relevance to this study. It then continues by advancing the understanding of the state of Information and Communication Technology (ICT) governance in public higher education institutions in South Africa by investigating the level of pervasiveness, the level of ICT process maturity and the alignment of ICT to the institutional processes within these institutions. Subsequently, this thesis results in the production of a contextually appropriate value framework that contributes towards an understanding of the need for the improvement of ICT governance. A survey of the extant literature on governance, ICT governance, and the frameworks and standards associated with governance indicates that the methodological approach currently favoured in ICT governance research is predominantly interpretive and based on surveys and interviews. This study leans towards a Design Science approach paradigm using surveys for the qualitative data collection process. The empirical research data was gathered from the highest ranking ICT officers at public higher education institutions in South Africa. This study makes contributions on a number of levels – from the first known measurement of ICT pervasiveness within the context of higher education, to the measurement of ICT process maturity and the measurement of the alignment of ICT and institutional processes, to the design of a value framework that breaks down governance into layers indicating which governance organs are appropriate at the relevant layers and which governance mechanisms can be used to address governance at each layer of governance. This study therefore makes a contribution to the ICT domain for development research by demonstrating praxis for the improvement of ICT governance implementation in the public higher education sector in South Africa. This study makes both method design and practical contributions to the ICT body of knowledge at various stages of the research process. These contributions include reflection on and analysis of the data gathering approaches that occur within the public higher education sector and in the complex environment of institutional autonomy and academic freedom; the use of Agency Theory to support the ‗governance intent‘ transfer between the layers of governance in the value framework and the synthesis of the improvement of ICT governance with value creation. The findings of this study further contribute to an understanding of the dynamics and interrelatedness of aspects of governance and management, while making a contribution to theoretical research by extending practical and empirical understanding of the ICT governance environment in the public higher education sector in South Africa.
- Full Text:
- Date Issued: 2013
- Authors: Johl, Christian Peter
- Date: 2013
- Subjects: Information technology -- South Africa -- Management , Universities and colleges -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9821 , http://hdl.handle.net/10948/d1020281
- Description: The public higher education sector in South Africa is governed by an act of Parliament which defines the governance organs and mechanisms required within institutions and the sector. This doctoral thesis begins by contextualising ICT governance within the levels of systemic governance in South Africa that have relevance to this study. It then continues by advancing the understanding of the state of Information and Communication Technology (ICT) governance in public higher education institutions in South Africa by investigating the level of pervasiveness, the level of ICT process maturity and the alignment of ICT to the institutional processes within these institutions. Subsequently, this thesis results in the production of a contextually appropriate value framework that contributes towards an understanding of the need for the improvement of ICT governance. A survey of the extant literature on governance, ICT governance, and the frameworks and standards associated with governance indicates that the methodological approach currently favoured in ICT governance research is predominantly interpretive and based on surveys and interviews. This study leans towards a Design Science approach paradigm using surveys for the qualitative data collection process. The empirical research data was gathered from the highest ranking ICT officers at public higher education institutions in South Africa. This study makes contributions on a number of levels – from the first known measurement of ICT pervasiveness within the context of higher education, to the measurement of ICT process maturity and the measurement of the alignment of ICT and institutional processes, to the design of a value framework that breaks down governance into layers indicating which governance organs are appropriate at the relevant layers and which governance mechanisms can be used to address governance at each layer of governance. This study therefore makes a contribution to the ICT domain for development research by demonstrating praxis for the improvement of ICT governance implementation in the public higher education sector in South Africa. This study makes both method design and practical contributions to the ICT body of knowledge at various stages of the research process. These contributions include reflection on and analysis of the data gathering approaches that occur within the public higher education sector and in the complex environment of institutional autonomy and academic freedom; the use of Agency Theory to support the ‗governance intent‘ transfer between the layers of governance in the value framework and the synthesis of the improvement of ICT governance with value creation. The findings of this study further contribute to an understanding of the dynamics and interrelatedness of aspects of governance and management, while making a contribution to theoretical research by extending practical and empirical understanding of the ICT governance environment in the public higher education sector in South Africa.
- Full Text:
- Date Issued: 2013
An improved mentoring model for student teachers on practicum in primary schools in Zimbabwe
- Authors: Jeko, Ishmael
- Date: 2013
- Subjects: Student teachers -- Zimbabwe , Student teaching -- Zimbabwe , Early childhood education -- Curricula , Teachers -- Training of -- Zimbabwe , Mentoring in education -- Zimbabwe , Lesson planning
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9571 , http://hdl.handle.net/10948/d1017553
- Description: As part of a drive to improve the quality of teachers, Zimbabwe introduced a school-based mentoring model in 1995, a move which regrettably seems not have borne fruit. Therefore, this study sought to propose an improved mentoring model for initial teacher training for primary school teachers. Efforts to improve the current mentoring could, however, be facilitated if they were informed by an empirically-based understanding of the shortcomings of the existing mentoring system for student teachers and teachers. In order to attain the above objective, this study adopted a multisite case study design, guided by the interpretive paradigm. A core of nine primary schools, drawn from the rural, urban and peri-urban areas of the Masvingo Province in Zimbabwe, was purposively selected to participate in the study. In the participating schools, key participants were student teachers and mentors, while school principals participated when they had time. A secondary group of primary schools were also identified to be used as validation of findings in a wider setting. An in-depth literature study on teacher education and mentoring was also carried out and this, combined with empirical data, illuminated the issues being investigated. The empirical data were primarily gathered through focus group and face-to-face individual semi-structured interviews, while participant observation (used in conjunction with informal unstructured interviews) and questionnaires were used to verify and triangulate data collected through the interviews. To safeguard the ethical integrity of the study, ethical approval from the relevant university committee, as well as the official consent of educational authorities, was obtained beforehand, as was the informed consent of individual participants. The research established that the support rendered to student teachers in the participating primary schools was largely inadequate and of a shallow mode, focusing primarily on facilitating the mastery of technical skills and the provision of psycho-social support, while being sorely deficient in empowering the student teachers with the skills and attitudes to reflectively and critically engage with their own and others‟ teaching practices. The mentoring was taking place in the context of field experience, organised along the apprenticeship model, hence located in an outmoded traditional paradigm of field experience, something which is regrettable at a time when international best practices seek to move towards a reflective-inquiry-oriented paradigm. Secondly, the research found that the participating schools were not structurally or culturally ready to take significant teacher training responsibility; hence the schools, in their present state, could be seen as constraining the smooth functioning of the mentoring model. Thirdly, some mentor-based factors also seemed to inhibit the functioning of the mentoring model. These included teachers who were attitudinally indisposed to accept student teachers as their professional colleagues, preferring to relate to them hierarchically and vertically, thereby limiting the emergence of a culture of professional collaboration and reciprocal learning relationships. In similar vein, the mentors‟ lack of training limited their capacity of mentors to perform the extended range of mentoring functions necessary for supporting student teachers trained in 21st century schools. The above conclusions and implications point towards the following recommendations: Mentor support for student teachers should be extended from the present superficial level to include functions that are oriented towards reflective practice. However, for this to happen, some adjustments will need to be made in the schools. These include, most importantly, making time available for mentoring activities. In order for the mentors to be able to perform their mentoring functions knowledgeably, they must be made fully aware of what they are supposed to do by providing them with the official documents spelling out mentoring expectations in schools. Additionally, the commitment of mentors to their duties could be made more sustainable by putting in place a clearly defined reward structure that is fully recognized officially and integrated into the employee grading system. To make school environments more propitious towards mentoring, schools must be structurally modified and re-cultured to create slots for mentoring activities, provide opportunities for informal professional interaction among teachers, as well as establish professional engagement forums, such as school-based learning circles. The research also suggests that student teachers should be allowed to choose their mentors through providing them with opportunities for early contact with their prospective mentoring partners. In an attempt to close the gap between college-based modules and field-based school experiences, the research further recommends that college-based modules be delivered in a way that ensures that they are fully integrated with student teachers‟ field experiences. Finally, mentoring could be better facilitated if schools and colleges adopted a partnership arrangement that is more aligned to mentoring. This implies provisionally shifting from the present separatist to the HEI-led partnership model, while preparing for the adoption of a fully-fledged collaborative partnership in the long term. The research was, however, by no means carried out perfectly. It was somewhat limited by its failure to take into account the view of officials from the Department of Education, as well as the input of colleagues in teacher education. In similar vein, the researcher felt that a more nuanced and fine-grained picture of the participants‟ mentoring experiences could have emerged if he had spent more time in the field, something which limited resources and work commitments did not allow him to do. Some significant issues arose from this study, but which it could not pursue. These include exploring the possibility of coming up with a model of teacher education that integrates ITE and CTPD in the context of mentoring, as well as conducting a similarly designed research into the mentoring that is taking place in secondary schools.
- Full Text:
- Date Issued: 2013
- Authors: Jeko, Ishmael
- Date: 2013
- Subjects: Student teachers -- Zimbabwe , Student teaching -- Zimbabwe , Early childhood education -- Curricula , Teachers -- Training of -- Zimbabwe , Mentoring in education -- Zimbabwe , Lesson planning
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9571 , http://hdl.handle.net/10948/d1017553
- Description: As part of a drive to improve the quality of teachers, Zimbabwe introduced a school-based mentoring model in 1995, a move which regrettably seems not have borne fruit. Therefore, this study sought to propose an improved mentoring model for initial teacher training for primary school teachers. Efforts to improve the current mentoring could, however, be facilitated if they were informed by an empirically-based understanding of the shortcomings of the existing mentoring system for student teachers and teachers. In order to attain the above objective, this study adopted a multisite case study design, guided by the interpretive paradigm. A core of nine primary schools, drawn from the rural, urban and peri-urban areas of the Masvingo Province in Zimbabwe, was purposively selected to participate in the study. In the participating schools, key participants were student teachers and mentors, while school principals participated when they had time. A secondary group of primary schools were also identified to be used as validation of findings in a wider setting. An in-depth literature study on teacher education and mentoring was also carried out and this, combined with empirical data, illuminated the issues being investigated. The empirical data were primarily gathered through focus group and face-to-face individual semi-structured interviews, while participant observation (used in conjunction with informal unstructured interviews) and questionnaires were used to verify and triangulate data collected through the interviews. To safeguard the ethical integrity of the study, ethical approval from the relevant university committee, as well as the official consent of educational authorities, was obtained beforehand, as was the informed consent of individual participants. The research established that the support rendered to student teachers in the participating primary schools was largely inadequate and of a shallow mode, focusing primarily on facilitating the mastery of technical skills and the provision of psycho-social support, while being sorely deficient in empowering the student teachers with the skills and attitudes to reflectively and critically engage with their own and others‟ teaching practices. The mentoring was taking place in the context of field experience, organised along the apprenticeship model, hence located in an outmoded traditional paradigm of field experience, something which is regrettable at a time when international best practices seek to move towards a reflective-inquiry-oriented paradigm. Secondly, the research found that the participating schools were not structurally or culturally ready to take significant teacher training responsibility; hence the schools, in their present state, could be seen as constraining the smooth functioning of the mentoring model. Thirdly, some mentor-based factors also seemed to inhibit the functioning of the mentoring model. These included teachers who were attitudinally indisposed to accept student teachers as their professional colleagues, preferring to relate to them hierarchically and vertically, thereby limiting the emergence of a culture of professional collaboration and reciprocal learning relationships. In similar vein, the mentors‟ lack of training limited their capacity of mentors to perform the extended range of mentoring functions necessary for supporting student teachers trained in 21st century schools. The above conclusions and implications point towards the following recommendations: Mentor support for student teachers should be extended from the present superficial level to include functions that are oriented towards reflective practice. However, for this to happen, some adjustments will need to be made in the schools. These include, most importantly, making time available for mentoring activities. In order for the mentors to be able to perform their mentoring functions knowledgeably, they must be made fully aware of what they are supposed to do by providing them with the official documents spelling out mentoring expectations in schools. Additionally, the commitment of mentors to their duties could be made more sustainable by putting in place a clearly defined reward structure that is fully recognized officially and integrated into the employee grading system. To make school environments more propitious towards mentoring, schools must be structurally modified and re-cultured to create slots for mentoring activities, provide opportunities for informal professional interaction among teachers, as well as establish professional engagement forums, such as school-based learning circles. The research also suggests that student teachers should be allowed to choose their mentors through providing them with opportunities for early contact with their prospective mentoring partners. In an attempt to close the gap between college-based modules and field-based school experiences, the research further recommends that college-based modules be delivered in a way that ensures that they are fully integrated with student teachers‟ field experiences. Finally, mentoring could be better facilitated if schools and colleges adopted a partnership arrangement that is more aligned to mentoring. This implies provisionally shifting from the present separatist to the HEI-led partnership model, while preparing for the adoption of a fully-fledged collaborative partnership in the long term. The research was, however, by no means carried out perfectly. It was somewhat limited by its failure to take into account the view of officials from the Department of Education, as well as the input of colleagues in teacher education. In similar vein, the researcher felt that a more nuanced and fine-grained picture of the participants‟ mentoring experiences could have emerged if he had spent more time in the field, something which limited resources and work commitments did not allow him to do. Some significant issues arose from this study, but which it could not pursue. These include exploring the possibility of coming up with a model of teacher education that integrates ITE and CTPD in the context of mentoring, as well as conducting a similarly designed research into the mentoring that is taking place in secondary schools.
- Full Text:
- Date Issued: 2013
Analysis of temporal and spatial variations in water storage by means of gravimetric and hydrologic methods in the region around the South African gravimetric observation station
- Authors: Mahed, Gaathier
- Date: 2013
- Subjects: Ground water -- South Africa , Geology -- South Africa , Hydrogeology -- South Africa , Water-supply -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/6714 , vital:21137
- Description: This work examines the use of gravity data and its application to subsurface water reservoirs in the immediate vicinity of the South African Geodynamic Observatory, Sutherland (SAGOS), situated in a semi-arid region of the Karoo region of South Africa, and underlain by the Karoo sedimentary rocks intruded by dolerite dykes and sills. SAGOS houses the only supergravity metre (SG) in Africa, and this thesis sets out to test its use in monitoring groundwater dynamics using hydrological and gravity data. The main aim of this work is the application of the SG data, in conjunction with hydrological data, to better understand episodic recharge of subsurface reservoirs. The importance of water as a resource, globally and specifically the Karoo, is reviewed in conjunction with supply and demand of water. This is to contextualise the socio-economic, technical as well as policy issues related to water resource management. Applicable technologies for water resource management and efficient water use are highlighted and the application of gravity to hydrology is introduced, including satellite as well as ground based tools. In addition, arid zone hydrology as well as recharge and its mechanisms are analysed in order to better understand these processes when examined from gravity measurements. Issues related to understanding flow within the vadose zone as well as in secondary aquifers are examined, and gravity residuals and subsurface hydrology are highlighted. Thereafter, a conceptual groundwater flow modelof the study area is developed using multiple tools. First, the geology around SAGOS was mapped using SPOT 5 imagery and then ground truthed. Second, stable isotopes and water chemistry analysis was undertaken on water samples from selected boreholes. The results allude to preferential flow acting as the main mechanism for groundwater recharge. Follow-up pump-tests illustrate that fracture connectivity is greatest at close proximity to the dyke. Soil mapping, using aerial photography was also undertaken. Duplex soils, enriched with clay at depth, dominate the study area. Using in-situ infiltration tests, it is shown that the alluvium, which lines the river beds, has a higher hydraulic conductivity than the other soils, confirming that these streams act as preferential conduits for subsurface recharge. Precipitation events were correlated against gravity residuals at 4 wells, over different time periods. The results are examined using time series analyses. Gravity residuals from well SA BK07, over a period of 24 hours after the rainfall event, delineate instances of negative correlations, as well as strong positive correlations (of up to 0.9). On the whole however, correlations between gravity and groundwater at SA BK07 are variable and weak, and in conjunction with water level measurements and water chemistry, the data suggest that this well is located in a dynamic conduit (throughflow) and not in a permanent groundwater reservoir. By contrast, other wells show strong positive correlations between gravity residuals and water levels following episodic recharge events for a later time series. Correlations between the water levels and gravity residuals in wells SA BK04, SA BK05 and SA BK 01 are in excess of 0.7 for specific rainfall events. In summary, the results suggests that gravity is an excellent tool for measuring episodic groundwater recharge within the immediate vicinity of the SAGOS. This implies that gravity can aid in monitoring groundwater losses/gains in arid and semi-arid areas. Recommendations for future work are highlighted at the end; these include the possible use of hydrological modelling of reservoirs at various scales and then comparing these results to the SG as well as GOCE and GRACE satellites data, and then improving numerical modelling of the groundwater dynamics for sites like Sutherland and the surrounding arid Karoo region, where sparse water shortages, and potential pollution related to fracking for shale-gas, are likely to compete with established water needs for farming and human consumption. It is also suggested that the gravity modelling be examined to better understand site specific scenarios and thus aid in improving the processing of the gravity signal.
- Full Text:
- Date Issued: 2013
- Authors: Mahed, Gaathier
- Date: 2013
- Subjects: Ground water -- South Africa , Geology -- South Africa , Hydrogeology -- South Africa , Water-supply -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/6714 , vital:21137
- Description: This work examines the use of gravity data and its application to subsurface water reservoirs in the immediate vicinity of the South African Geodynamic Observatory, Sutherland (SAGOS), situated in a semi-arid region of the Karoo region of South Africa, and underlain by the Karoo sedimentary rocks intruded by dolerite dykes and sills. SAGOS houses the only supergravity metre (SG) in Africa, and this thesis sets out to test its use in monitoring groundwater dynamics using hydrological and gravity data. The main aim of this work is the application of the SG data, in conjunction with hydrological data, to better understand episodic recharge of subsurface reservoirs. The importance of water as a resource, globally and specifically the Karoo, is reviewed in conjunction with supply and demand of water. This is to contextualise the socio-economic, technical as well as policy issues related to water resource management. Applicable technologies for water resource management and efficient water use are highlighted and the application of gravity to hydrology is introduced, including satellite as well as ground based tools. In addition, arid zone hydrology as well as recharge and its mechanisms are analysed in order to better understand these processes when examined from gravity measurements. Issues related to understanding flow within the vadose zone as well as in secondary aquifers are examined, and gravity residuals and subsurface hydrology are highlighted. Thereafter, a conceptual groundwater flow modelof the study area is developed using multiple tools. First, the geology around SAGOS was mapped using SPOT 5 imagery and then ground truthed. Second, stable isotopes and water chemistry analysis was undertaken on water samples from selected boreholes. The results allude to preferential flow acting as the main mechanism for groundwater recharge. Follow-up pump-tests illustrate that fracture connectivity is greatest at close proximity to the dyke. Soil mapping, using aerial photography was also undertaken. Duplex soils, enriched with clay at depth, dominate the study area. Using in-situ infiltration tests, it is shown that the alluvium, which lines the river beds, has a higher hydraulic conductivity than the other soils, confirming that these streams act as preferential conduits for subsurface recharge. Precipitation events were correlated against gravity residuals at 4 wells, over different time periods. The results are examined using time series analyses. Gravity residuals from well SA BK07, over a period of 24 hours after the rainfall event, delineate instances of negative correlations, as well as strong positive correlations (of up to 0.9). On the whole however, correlations between gravity and groundwater at SA BK07 are variable and weak, and in conjunction with water level measurements and water chemistry, the data suggest that this well is located in a dynamic conduit (throughflow) and not in a permanent groundwater reservoir. By contrast, other wells show strong positive correlations between gravity residuals and water levels following episodic recharge events for a later time series. Correlations between the water levels and gravity residuals in wells SA BK04, SA BK05 and SA BK 01 are in excess of 0.7 for specific rainfall events. In summary, the results suggests that gravity is an excellent tool for measuring episodic groundwater recharge within the immediate vicinity of the SAGOS. This implies that gravity can aid in monitoring groundwater losses/gains in arid and semi-arid areas. Recommendations for future work are highlighted at the end; these include the possible use of hydrological modelling of reservoirs at various scales and then comparing these results to the SG as well as GOCE and GRACE satellites data, and then improving numerical modelling of the groundwater dynamics for sites like Sutherland and the surrounding arid Karoo region, where sparse water shortages, and potential pollution related to fracking for shale-gas, are likely to compete with established water needs for farming and human consumption. It is also suggested that the gravity modelling be examined to better understand site specific scenarios and thus aid in improving the processing of the gravity signal.
- Full Text:
- Date Issued: 2013
Assessing soil carbon and carbon dioxide effluxes under different vegetation cover conditions in the Eastern Cape Province, South Africa
- Authors: Zengeni, Rebecca
- Date: 2013
- Subjects: Soils -- Carbon content -- Measurement , Carbon dioxide mitigation -- South Africa , Greenhouse gas mitigation -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10665 , http://hdl.handle.net/10948/d1018676
- Description: Albany thicket is prevalent in the Eastern Cape Province of South Africa. Its spread has diminished through overgrazing and heavy browsing by animals, land clearance and urban expansion. The result is highly degraded land characterized by invasion of alien species. There is a wealth of documented evidence on the high carbon sequestration ability of thicket biome, but not much has been done to assess its effect on carbon dioxide emissions from the soil. Given that the concentration of atmospheric greenhouse gases has been constantly rising since the industrial era, it is imperative to assess the influence of thicket biome as a source or sink of these gases. There is evidence of shifts in the climate in southern Africa as reflected by changes in rainfall patterns, increased temperatures, recurrent droughts and fires. As such, the historical rainfall variability in an Albany thicket region and its interaction with the temporal land use / cover changes was studied. This served to give some background information about the study area for more detailed study on C and carbon dioxide effluxes in thicket vegetation under different levels of degradation. This study thus aimed to determine the influence of thicket vegetation at various levels of degradation on soil carbon and carbon dioxide fluxes. The impact of plant photosynthetic pathway on soil C residence time and gas effluxes were analysed to elucidate on the land-use and cover patterns occurring in the area. All this was done to shed some light on the role of soil and thicket vegetation on carbon dioxide emissions and C storage in the spectrum of a shifting climate. The main area of research was Amakhala reserve in an Albany thicket in Eastern Cape Province; and it concentrated on three land cover types namely intact thicket, degraded thicket and grassland. The objectives mentioned above were achieved by assessing historical rainfall variability from 1970 to 2010 through trend and time series analysis at nine rainfall stations located at Amakhala reserve, Grahamstown, Bathurst, Port Alfred, Uitenhage and Port Elizabeth. The land use changes that have occurred in the Albany thicket region covering Amakhala reserve, Grahamstown, Bathurst and Port Alfred were also assessed for 1989, 1999 and 2009 through satellite image analysis with Idrisi Andes GIS software; then their interaction with rainfall variability were determined. To elucidate on the vegetation species composition and land use / cover changes that have occurred in the study area, plant biomass as well carbon (C) and nitrogen (N) isotope measurements were done. Plant biomass was assessed for the dominant species through use of pre-existing allometric equations that required data on plant basal diameter, canopy area, stem numbers and height. The plant carbon was then estimated through use of a conversion factor of 0.48 on above-ground biomass, while soil organic C was determined through the modified Walkely - Black method. Carbon and N isotope ratios were determined from the foliar material of three replicate samples of dominant plant species then analyzed through mass spectrometry. Soil carbon dioxide effluxes were then monitored in each of the intact thicket (IT), degraded thicket (DT) and grassland (G) over a 10 month period; by measuring the net carbon dioxide exchange rate (NCER) through the dynamic chamber method. An automated carbon dioxide exchange analyzer, coupled to a soil temperature probe and photosynthetic active radiation (PAR) sensor was used; with NCER measurements taken every 20-30 days. Soil temperature, moisture, penetration resistance and PAR readings were taken during each assay and later used to interpret the NCER. Results showed that long term variability in annual rainfall had a declining trend at Grahamstown (r = -0.59), Uitenhage and Bathurst stations (r = -0.32 at both stations), but was not significant at Amakhala, Port Alfred and Port Elizabeth stations. Most reductions in rainfall occurred in the 1980s and 1990s with the autumn, winter and summer rainfalls, the daily rainfall index and the daily rainfall subclasses of 10 mm and above showing a similar trend. The land use change detection gave a significant increase in proportion of degraded and transformed (moderately degraded) land between 1989 and 2009 with most of the increases occurring from 1989 to 1999, while farmland area decreased by 1.8 percent over the years. Thus the Albany region had over 30 percent of its land occupied by transformed vegetation, with heavy browsing and uncontrolled grazing being attributed to the destruction of pristine vegetation. Land-use change to game ranching and goat pastoralism was attributed to the reduction in farmland. Rainfall variability – land use change linkages were most significant in 1999 that recorded the least rainfall and had the lowest mean, maximum and sum of the NDVI. Grahamstown had the most significant rainfall-NDVI trends as it had the lowest NDVIs in 1999 when rainfall was lowest, the highest NDVI in 1989 when rainfall was highest and moderate NDVIs in 2009 when rainfall was moderate. Vegetation at the IT was characterized by a dense thicket with diverse growth forms of canopy trees, woody shrubs, succulent shrubs and ephemerals which mostly had the C3 type of pathway. This was in contrast with the IT soil isotopy that showed more positive C isotope ratios, indicating a switch between C3 and CAM photosynthesis in original vegetation. Most of the canopy trees had disappeared in the DT to be replaced by herbs, shrubs and grasses. As such, there was a huge difference in isotope ratios between DT plants and soils with the plants having mostly C3 metabolism while the soil showed a predominance of CAM plants in previous vegetation, indicating significant changes in land cover. The G site mostly comprised the grasses Themeda triandra and Panicum maximum and a few herbs. It maintained a dominance of C4 metabolism in both plants and soils showing very little change in species composition over the years. Because of the higher species diversity at IT, its soil organic C was quite high reaching levels of 3.4 percent (i.e. 3.4 t C / ha) in the top 10 cm then decreasing with depth (p < 0.001); but was moderate at DT (1.1-1.3 percent) and very low at G ( 0.5 percent C) (p < 0.001). In the same manner above-ground biomass was highest at IT i.e. 330 000 kg/ha; but was only 22 000 kg/ha in DT and as low as 6 700 kg/ha in G vegetation. High biomass at IT was mostly attributed to the succulent shrub Portulacaria afra and the canopy trees Euclea undulate, Rhus longispina and Schotia afra. This above-ground biomass translated to biomass C amounts of 158 000 kg/ha at IT, 10 600 kg/ha at DT and 3 200 kg/ha at G. Thus the IT had the highest while G the least and DT moderate plant and soil C sequestration ability. In all, the conversion of IT to DT led to a net loss of 147 000 Kg of biomass C / ha and 12 000kg less organic C / ha of land. Soil carbon dioxide effluxes were however variable between seasons as they were affected by differences in soil properties and seasonal weather patterns. High soil moisture levels (up to 16 percent gravimetric moisture) resulted in reduced soil penetration resistance (1 to 4 Kg/cm2) which raised effluxes at G and DT sites (up to 1.2 μmols m-2 sec-1) in winter, while low moisture (2 percent) resulted in hard dry soil (14 Kgm-2 penetration resistance) with suppressed CO2 effluxes in spring (0.2 μmols m-2 sec-1) especially in DT and G soils. Rising temperature generally caused accelerated gas emissions but only when moisture was not limiting (as was the case in IT). Thus the high summer temperatures (up to 40oC) gave lower effluxes especially in DT and G (< 1 μm-2sec-1) due to limited moisture supply (< 10 percent); while the Autumn period that had very high temperature (up to 48 oC) and good moisture (up to 16 percent) saw accelerated soil CO2 emissions (averaging 2 μmols m-2 sec-1) from all cover types. The high biomass and litter fall at IT served as ready substrate for soil respiration as long as moisture was not limiting and temperatures were favourable, while reduced cover at DT resulted in poor moisture conservation and creation of hard dry soils in spring and summer with reduced respiration. It was concluded that the DT had high CO2 effluxes in winter and reduced emissions in summer; while the opposite was true for the IT. All the cover types had minimal CO2 effluxes in spring and accelerated emissions in autumn. The grassland on the other hand was a fairly moderate source or sink of CO2 in most seasons compared with the other two covers. It was observed that an environment of good moisture and low-moderate temperatures (such as that in the winter) minimises effluxes while maintaining good plant productivity. It was concluded that thicket vegetation is a good sink of carbon that should be preserved in its natural condition to optimize its carbon sequestration potential. All three land covers served as sources or sinks of CO2 depending on soil and seasonal conditions. Thus high moisture and low penetration resistance generally increased effluxes of thicket ecosystems. The effect of increasing temperature on effluxes was only significant when moisture was not limiting. Conditions of good moisture and low-moderate temperatures gave reasonable amounts of effluxes while maintaining good plant productivity. Though the dry soil conditions significantly reduced effluxes in all land covers; they were not desirable since they decreased plant productivity and ultimately its C sequestration potential. Moreover, prolonged dry conditions only serve to exacerbate recovery of thicket plants as they increase mortality of canopy species in degraded and transformed areas in comparison with intact thicket.
- Full Text:
- Date Issued: 2013
- Authors: Zengeni, Rebecca
- Date: 2013
- Subjects: Soils -- Carbon content -- Measurement , Carbon dioxide mitigation -- South Africa , Greenhouse gas mitigation -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10665 , http://hdl.handle.net/10948/d1018676
- Description: Albany thicket is prevalent in the Eastern Cape Province of South Africa. Its spread has diminished through overgrazing and heavy browsing by animals, land clearance and urban expansion. The result is highly degraded land characterized by invasion of alien species. There is a wealth of documented evidence on the high carbon sequestration ability of thicket biome, but not much has been done to assess its effect on carbon dioxide emissions from the soil. Given that the concentration of atmospheric greenhouse gases has been constantly rising since the industrial era, it is imperative to assess the influence of thicket biome as a source or sink of these gases. There is evidence of shifts in the climate in southern Africa as reflected by changes in rainfall patterns, increased temperatures, recurrent droughts and fires. As such, the historical rainfall variability in an Albany thicket region and its interaction with the temporal land use / cover changes was studied. This served to give some background information about the study area for more detailed study on C and carbon dioxide effluxes in thicket vegetation under different levels of degradation. This study thus aimed to determine the influence of thicket vegetation at various levels of degradation on soil carbon and carbon dioxide fluxes. The impact of plant photosynthetic pathway on soil C residence time and gas effluxes were analysed to elucidate on the land-use and cover patterns occurring in the area. All this was done to shed some light on the role of soil and thicket vegetation on carbon dioxide emissions and C storage in the spectrum of a shifting climate. The main area of research was Amakhala reserve in an Albany thicket in Eastern Cape Province; and it concentrated on three land cover types namely intact thicket, degraded thicket and grassland. The objectives mentioned above were achieved by assessing historical rainfall variability from 1970 to 2010 through trend and time series analysis at nine rainfall stations located at Amakhala reserve, Grahamstown, Bathurst, Port Alfred, Uitenhage and Port Elizabeth. The land use changes that have occurred in the Albany thicket region covering Amakhala reserve, Grahamstown, Bathurst and Port Alfred were also assessed for 1989, 1999 and 2009 through satellite image analysis with Idrisi Andes GIS software; then their interaction with rainfall variability were determined. To elucidate on the vegetation species composition and land use / cover changes that have occurred in the study area, plant biomass as well carbon (C) and nitrogen (N) isotope measurements were done. Plant biomass was assessed for the dominant species through use of pre-existing allometric equations that required data on plant basal diameter, canopy area, stem numbers and height. The plant carbon was then estimated through use of a conversion factor of 0.48 on above-ground biomass, while soil organic C was determined through the modified Walkely - Black method. Carbon and N isotope ratios were determined from the foliar material of three replicate samples of dominant plant species then analyzed through mass spectrometry. Soil carbon dioxide effluxes were then monitored in each of the intact thicket (IT), degraded thicket (DT) and grassland (G) over a 10 month period; by measuring the net carbon dioxide exchange rate (NCER) through the dynamic chamber method. An automated carbon dioxide exchange analyzer, coupled to a soil temperature probe and photosynthetic active radiation (PAR) sensor was used; with NCER measurements taken every 20-30 days. Soil temperature, moisture, penetration resistance and PAR readings were taken during each assay and later used to interpret the NCER. Results showed that long term variability in annual rainfall had a declining trend at Grahamstown (r = -0.59), Uitenhage and Bathurst stations (r = -0.32 at both stations), but was not significant at Amakhala, Port Alfred and Port Elizabeth stations. Most reductions in rainfall occurred in the 1980s and 1990s with the autumn, winter and summer rainfalls, the daily rainfall index and the daily rainfall subclasses of 10 mm and above showing a similar trend. The land use change detection gave a significant increase in proportion of degraded and transformed (moderately degraded) land between 1989 and 2009 with most of the increases occurring from 1989 to 1999, while farmland area decreased by 1.8 percent over the years. Thus the Albany region had over 30 percent of its land occupied by transformed vegetation, with heavy browsing and uncontrolled grazing being attributed to the destruction of pristine vegetation. Land-use change to game ranching and goat pastoralism was attributed to the reduction in farmland. Rainfall variability – land use change linkages were most significant in 1999 that recorded the least rainfall and had the lowest mean, maximum and sum of the NDVI. Grahamstown had the most significant rainfall-NDVI trends as it had the lowest NDVIs in 1999 when rainfall was lowest, the highest NDVI in 1989 when rainfall was highest and moderate NDVIs in 2009 when rainfall was moderate. Vegetation at the IT was characterized by a dense thicket with diverse growth forms of canopy trees, woody shrubs, succulent shrubs and ephemerals which mostly had the C3 type of pathway. This was in contrast with the IT soil isotopy that showed more positive C isotope ratios, indicating a switch between C3 and CAM photosynthesis in original vegetation. Most of the canopy trees had disappeared in the DT to be replaced by herbs, shrubs and grasses. As such, there was a huge difference in isotope ratios between DT plants and soils with the plants having mostly C3 metabolism while the soil showed a predominance of CAM plants in previous vegetation, indicating significant changes in land cover. The G site mostly comprised the grasses Themeda triandra and Panicum maximum and a few herbs. It maintained a dominance of C4 metabolism in both plants and soils showing very little change in species composition over the years. Because of the higher species diversity at IT, its soil organic C was quite high reaching levels of 3.4 percent (i.e. 3.4 t C / ha) in the top 10 cm then decreasing with depth (p < 0.001); but was moderate at DT (1.1-1.3 percent) and very low at G ( 0.5 percent C) (p < 0.001). In the same manner above-ground biomass was highest at IT i.e. 330 000 kg/ha; but was only 22 000 kg/ha in DT and as low as 6 700 kg/ha in G vegetation. High biomass at IT was mostly attributed to the succulent shrub Portulacaria afra and the canopy trees Euclea undulate, Rhus longispina and Schotia afra. This above-ground biomass translated to biomass C amounts of 158 000 kg/ha at IT, 10 600 kg/ha at DT and 3 200 kg/ha at G. Thus the IT had the highest while G the least and DT moderate plant and soil C sequestration ability. In all, the conversion of IT to DT led to a net loss of 147 000 Kg of biomass C / ha and 12 000kg less organic C / ha of land. Soil carbon dioxide effluxes were however variable between seasons as they were affected by differences in soil properties and seasonal weather patterns. High soil moisture levels (up to 16 percent gravimetric moisture) resulted in reduced soil penetration resistance (1 to 4 Kg/cm2) which raised effluxes at G and DT sites (up to 1.2 μmols m-2 sec-1) in winter, while low moisture (2 percent) resulted in hard dry soil (14 Kgm-2 penetration resistance) with suppressed CO2 effluxes in spring (0.2 μmols m-2 sec-1) especially in DT and G soils. Rising temperature generally caused accelerated gas emissions but only when moisture was not limiting (as was the case in IT). Thus the high summer temperatures (up to 40oC) gave lower effluxes especially in DT and G (< 1 μm-2sec-1) due to limited moisture supply (< 10 percent); while the Autumn period that had very high temperature (up to 48 oC) and good moisture (up to 16 percent) saw accelerated soil CO2 emissions (averaging 2 μmols m-2 sec-1) from all cover types. The high biomass and litter fall at IT served as ready substrate for soil respiration as long as moisture was not limiting and temperatures were favourable, while reduced cover at DT resulted in poor moisture conservation and creation of hard dry soils in spring and summer with reduced respiration. It was concluded that the DT had high CO2 effluxes in winter and reduced emissions in summer; while the opposite was true for the IT. All the cover types had minimal CO2 effluxes in spring and accelerated emissions in autumn. The grassland on the other hand was a fairly moderate source or sink of CO2 in most seasons compared with the other two covers. It was observed that an environment of good moisture and low-moderate temperatures (such as that in the winter) minimises effluxes while maintaining good plant productivity. It was concluded that thicket vegetation is a good sink of carbon that should be preserved in its natural condition to optimize its carbon sequestration potential. All three land covers served as sources or sinks of CO2 depending on soil and seasonal conditions. Thus high moisture and low penetration resistance generally increased effluxes of thicket ecosystems. The effect of increasing temperature on effluxes was only significant when moisture was not limiting. Conditions of good moisture and low-moderate temperatures gave reasonable amounts of effluxes while maintaining good plant productivity. Though the dry soil conditions significantly reduced effluxes in all land covers; they were not desirable since they decreased plant productivity and ultimately its C sequestration potential. Moreover, prolonged dry conditions only serve to exacerbate recovery of thicket plants as they increase mortality of canopy species in degraded and transformed areas in comparison with intact thicket.
- Full Text:
- Date Issued: 2013
Atmospheric pressure metal-organic vapour phase epitaxial growth of InAs/GaSb strained layer superlattices
- Authors: Miya, Senzo Simo
- Date: 2013
- Subjects: Gallium arsenide semiconductors , Organometallic compounds , Compound semiconductors , Metal organic chemical vapor deposition , Superlattices as materials , Epitaxy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10557 , http://hdl.handle.net/10948/d1020866
- Description: The importance of infrared (IR) technology (for detection in the 3-5 μm and 8-14 μm atmospheric windows) has spread from military applications to civilian applications since World War II. The commercial IR detector market in these wavelength ranges is dominated by mercury cadmium telluride (MCT) alloys. The use of these alloys has, however, been faced with technological difficulties. One of the materials that have been tipped to be suitable to replace MCT is InAs/InxGa1-xSb strained layer superlattices (SLS’s). Atmospheric pressure metal-organic vapour phase epitaxy (MOVPE) has been used to grow InAs/GaSb strained layer superlattices (SLS’s) at 510 °C in this study. This is a starting point towards the development of MOVPE InAs/InxGa1-xSb SLS’s using the same system. Before the SLS’s could be attempted, the growth parameters for GaSb were optimised. Growth parameters for InAs were taken from reports on previous studies conducted using the same reactor. Initially, trimethylgallium, a source that has been used extensively in the same growth system for the growth of GaSb and InxGa1-xSb was intended to be used for gallium species. The high growth rates yielded by this source were too large for the growth of SLS structures, however. Thus, triethylgallium (rarely used for atmospheric pressure MOVPE) was utilized. GaSb layers (between 1 and 2 μm thick) were grown at two different temperatures (550 °C and 510 °C) with a varying V/III ratio. A V/III ratio of 1.5 was found to be optimal at 550 °C. However, the low incorporation efficiency of indium into GaSb at this temperature was inadequate to obtain InxGa1-xSb with an indium mole fraction (x) of around 0.3, which had previously been reported to be optimal for the performance of InAs/InxGa1-xSb SLS’s, due to the maximum splitting of the valence mini bands for this composition. The growth temperature was thus lowered to 510 °C. This resulted in an increase in the optimum V/III ratio to 1.75 for GaSb and yielded much higher incorporation efficiencies of indium in InxGa1-xSb. However, this lower growth temperature also produced poorer surface morphologies for both the binary and ternary layers, due to the reduced surface diffusion of the adsorbed species. An interface control study during the growth of InAs/GaSb SLS’s was subsequently conducted, by investigating the influence of different gas switching sequences on the interface type and quality. It was noted that the growth of SLS’s without any growth interruptions at the interfaces leads to tensile strained SLS’s (GaAs-like interfaces) with a rather large lattice mismatch. A 5 second flow of TMSb over the InAs surface and a flow of H2 over GaSb surface yielded compressively strained SLS’s. Flowing TMIn for 1 second and following by a flow of TMSb for 4 seconds over the GaSb surface, while flowing H2 for 5 seconds over the InAs surface, resulted in SLS’s with GaAs-like interfacial layers and a reduced lattice mismatch. Temperature gradients across the surface of the susceptor led to SLS’s with different structural quality. High resolution x-ray diffraction (HRXRD) was used to determine the thicknesses as well as the type of interfacial layers. The physical parameters of the SLS’s obtained from simulating the HRXRD spectra were comparable to the parameters obtained from cross sectional transmission electron microscopy (XTEM) images. The thicknesses of the layers and the interface type played a major role in determining the cut-off wavelength of the SLS’s.
- Full Text:
- Date Issued: 2013
- Authors: Miya, Senzo Simo
- Date: 2013
- Subjects: Gallium arsenide semiconductors , Organometallic compounds , Compound semiconductors , Metal organic chemical vapor deposition , Superlattices as materials , Epitaxy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10557 , http://hdl.handle.net/10948/d1020866
- Description: The importance of infrared (IR) technology (for detection in the 3-5 μm and 8-14 μm atmospheric windows) has spread from military applications to civilian applications since World War II. The commercial IR detector market in these wavelength ranges is dominated by mercury cadmium telluride (MCT) alloys. The use of these alloys has, however, been faced with technological difficulties. One of the materials that have been tipped to be suitable to replace MCT is InAs/InxGa1-xSb strained layer superlattices (SLS’s). Atmospheric pressure metal-organic vapour phase epitaxy (MOVPE) has been used to grow InAs/GaSb strained layer superlattices (SLS’s) at 510 °C in this study. This is a starting point towards the development of MOVPE InAs/InxGa1-xSb SLS’s using the same system. Before the SLS’s could be attempted, the growth parameters for GaSb were optimised. Growth parameters for InAs were taken from reports on previous studies conducted using the same reactor. Initially, trimethylgallium, a source that has been used extensively in the same growth system for the growth of GaSb and InxGa1-xSb was intended to be used for gallium species. The high growth rates yielded by this source were too large for the growth of SLS structures, however. Thus, triethylgallium (rarely used for atmospheric pressure MOVPE) was utilized. GaSb layers (between 1 and 2 μm thick) were grown at two different temperatures (550 °C and 510 °C) with a varying V/III ratio. A V/III ratio of 1.5 was found to be optimal at 550 °C. However, the low incorporation efficiency of indium into GaSb at this temperature was inadequate to obtain InxGa1-xSb with an indium mole fraction (x) of around 0.3, which had previously been reported to be optimal for the performance of InAs/InxGa1-xSb SLS’s, due to the maximum splitting of the valence mini bands for this composition. The growth temperature was thus lowered to 510 °C. This resulted in an increase in the optimum V/III ratio to 1.75 for GaSb and yielded much higher incorporation efficiencies of indium in InxGa1-xSb. However, this lower growth temperature also produced poorer surface morphologies for both the binary and ternary layers, due to the reduced surface diffusion of the adsorbed species. An interface control study during the growth of InAs/GaSb SLS’s was subsequently conducted, by investigating the influence of different gas switching sequences on the interface type and quality. It was noted that the growth of SLS’s without any growth interruptions at the interfaces leads to tensile strained SLS’s (GaAs-like interfaces) with a rather large lattice mismatch. A 5 second flow of TMSb over the InAs surface and a flow of H2 over GaSb surface yielded compressively strained SLS’s. Flowing TMIn for 1 second and following by a flow of TMSb for 4 seconds over the GaSb surface, while flowing H2 for 5 seconds over the InAs surface, resulted in SLS’s with GaAs-like interfacial layers and a reduced lattice mismatch. Temperature gradients across the surface of the susceptor led to SLS’s with different structural quality. High resolution x-ray diffraction (HRXRD) was used to determine the thicknesses as well as the type of interfacial layers. The physical parameters of the SLS’s obtained from simulating the HRXRD spectra were comparable to the parameters obtained from cross sectional transmission electron microscopy (XTEM) images. The thicknesses of the layers and the interface type played a major role in determining the cut-off wavelength of the SLS’s.
- Full Text:
- Date Issued: 2013
Characterisation and biotic classification of Eastern Cape mixed substrate shores
- Authors: Garner, Cornelia Johanna
- Date: 2013
- Subjects: Coastal sediments -- South Africa -- Eastern Cape , Coastal biodiversity --- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10641 , http://hdl.handle.net/10948/d1020825
- Description: A significant proportion of the South African coastline is composed of both soft (mostly sand) and hard (mostly bedrock) substrata, i.e. “mixed”. This study described and classified macrobenthic assemblages of 20 Eastern Cape mixed substrate shores that differed in shore topography and the extent and position of intertidal rock and sand. A stratified random approach was used. Species richness, composition, abundance and environmental variables were determined. Commonly used beach indices were calculated. A total of 78 macrofaunal and 172 macroalgal species from rock substrate assemblages and 205 macrofauna species from sediment were recorded. Total species richness and richness per substratum exceeded that of sandy beaches devoid of rock and rocky shores with no sand. Rhodophyta were the most diverse and abundant algae, dominating all low-elevation rock surfaces as midlittoral and infralittoral turfs. Chlorophyta diversity was higher than at rocky shores, contributing more to cover-abundance at study sites and in microhabitats with an increased sand load. Sessile macrofauna species richness and abundance was lower than that of rocky shores. Polychaetes and crustaceans were the most diverse and abundant beach infauna. Species richness of both substrates declined from the low shore towards the high shore, but abundance trends varied substantially. The presence and extent of an intertidal biotope/subzone at either substrate depended on substrate availability.The supralittoral fringe in both substrate types was most often affected. Zonal overlap was evident on rock substrate: assemblages of raised midlittoral rock surfaces were enriched by species from lower surfaces sometimes leading to elimination of character taxa. Classification and ordination identified three potential mixed substrate shore biotic types: Biotic type A (Jania-Corallina- Polysiphonia turf) was characterised by robustly-textured algal turfs, a lowered predominance and diversity of polychaetes and an increase in crustacean abundance and diversity in sediment. Biotic type B (Polysiphonia-Tayloriella-Caulacanthus turf) had intermediately and biotic type C (Arthrocardia-Laurencia turf) the most sheltered eulittoral zones and beaches. DCCA identified the major environmental parameters affecting the macrobiota as: the level of wave energy, geological control of waves by hard substrate, sediment grain size and sediment inundation. A strong cross-shore wave attenuation results in sheltered sediments and midshore rock surfaces. Beach macrofauna were highly variable and diverse, which directly opposes previous perceptions about the sediment-bound biota of mixed substrate shores. The hierarchical cluster analysis produced a biotic classification of mixed substrate shores that was indicative of a biotic response to the total effects of leading environmental parameters. Macrobenthos of rock surfaces and sediment therefore showed potential to be used as an alternative or complementary to physical characteristics in classifying mixed substrate shores.
- Full Text:
- Date Issued: 2013
- Authors: Garner, Cornelia Johanna
- Date: 2013
- Subjects: Coastal sediments -- South Africa -- Eastern Cape , Coastal biodiversity --- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10641 , http://hdl.handle.net/10948/d1020825
- Description: A significant proportion of the South African coastline is composed of both soft (mostly sand) and hard (mostly bedrock) substrata, i.e. “mixed”. This study described and classified macrobenthic assemblages of 20 Eastern Cape mixed substrate shores that differed in shore topography and the extent and position of intertidal rock and sand. A stratified random approach was used. Species richness, composition, abundance and environmental variables were determined. Commonly used beach indices were calculated. A total of 78 macrofaunal and 172 macroalgal species from rock substrate assemblages and 205 macrofauna species from sediment were recorded. Total species richness and richness per substratum exceeded that of sandy beaches devoid of rock and rocky shores with no sand. Rhodophyta were the most diverse and abundant algae, dominating all low-elevation rock surfaces as midlittoral and infralittoral turfs. Chlorophyta diversity was higher than at rocky shores, contributing more to cover-abundance at study sites and in microhabitats with an increased sand load. Sessile macrofauna species richness and abundance was lower than that of rocky shores. Polychaetes and crustaceans were the most diverse and abundant beach infauna. Species richness of both substrates declined from the low shore towards the high shore, but abundance trends varied substantially. The presence and extent of an intertidal biotope/subzone at either substrate depended on substrate availability.The supralittoral fringe in both substrate types was most often affected. Zonal overlap was evident on rock substrate: assemblages of raised midlittoral rock surfaces were enriched by species from lower surfaces sometimes leading to elimination of character taxa. Classification and ordination identified three potential mixed substrate shore biotic types: Biotic type A (Jania-Corallina- Polysiphonia turf) was characterised by robustly-textured algal turfs, a lowered predominance and diversity of polychaetes and an increase in crustacean abundance and diversity in sediment. Biotic type B (Polysiphonia-Tayloriella-Caulacanthus turf) had intermediately and biotic type C (Arthrocardia-Laurencia turf) the most sheltered eulittoral zones and beaches. DCCA identified the major environmental parameters affecting the macrobiota as: the level of wave energy, geological control of waves by hard substrate, sediment grain size and sediment inundation. A strong cross-shore wave attenuation results in sheltered sediments and midshore rock surfaces. Beach macrofauna were highly variable and diverse, which directly opposes previous perceptions about the sediment-bound biota of mixed substrate shores. The hierarchical cluster analysis produced a biotic classification of mixed substrate shores that was indicative of a biotic response to the total effects of leading environmental parameters. Macrobenthos of rock surfaces and sediment therefore showed potential to be used as an alternative or complementary to physical characteristics in classifying mixed substrate shores.
- Full Text:
- Date Issued: 2013
Exploring interventions for participation of emerging farmers in the Eastern Cape ostrich-industry supply chain
- Authors: Pittaway, Timothy
- Date: 2013
- Subjects: Farmers -- South Africa -- Eastern Cape , Ostrich products industry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10596 , http://hdl.handle.net/10948/d1021008
- Description: The changing agricultural environment (dualistic agricultural landscape, land reform programme, market liberalisation and globalisation) has caused emerging ostrich farmers to become increasingly isolated. Governmental agriculture reforms and public sector interventions have been insufficient to address all the challenges faced by rural ostrich farmers in the Eastern Cape. Participation in the ostrich supply chain for emerging farmers in the Eastern Cape is currently unsustainable as a result of avian influenza, control and registration protocols for ostriches (VPN04), structural barriers in marketing, technical constraints and a lack of market participation. People in the rural areas of the Eastern Cape are challenged by inferior infrastructure, poor site conditions, low earnings, poor access to health services and unreliable water sources. The marginal conditions and prevalent complexities in which agriculture is practised require costly resource intervention. Intensive ostrich production necessitates continuous genetic improvement, methodical record keeping, intensive egg incubation methods and highmaintenance chick rearing and ostrich handling while minimising feed costs throughout this process. Rural farmers have not embraced ostrich farming in the same way as they have done with other livestock farming because it does not offer the anthropological functions that traditional livestock farming provides. The ostrich supply chain requires a wide range of activities to bring products to the final consumer. The worth of ostrich production lies mainly in the higher returns which are achieved only through the export markets. Today the ostrich industry has become vulnerable to market cannibalism, a lack of market development, unregulated numbers of ostriches and recurring international meat bans. The deregulation of the ostrich single-channel marketing system had a substantial effect on the value chain on which farmers depended for market access and market protection. As the majority of ostrich products are being exported to the European Union, the role of intermediary agencies is becoming an important factor influencing entry into the high-end markets. This agent structure that represents the South African ostrich industry is vital for the distribution, market penetration and regulation of the ostrich products. The ostrich leather, which is today the main product line, is primarily used for luxury goods and is susceptible to economic downturn and over-supply. The ostrich meat industry has been severely influenced by outbreaks of avian influenza and processors now pre-heat the meat in order to maintain export. However, this preheating meat facility is only for export produce and available to farmers who conform to VPN04 and have officially registered farms. The relevant South African government departments played a crucial role in identifying avian influenza outbreaks and liaising with the European Union about avian influenza isolation strategies. No previous studies have been conducted on the participation of emerging farmers in the Eastern Cape ostrich-industry supply chain and on the interventions required to address the multiple constraints and forces in this sector. This led to a study with research emphasis on the required capacity for supply-chain participation and the supporting mechanisms that would be required for emerging ostrich farmers to integrate successfully into this supply chain. An exploratory research approach was chosen for the investigation, as no earlier research has been undertaken that could serve as a source of reliable data or reference. A triangulation research methodology using both the quantitative and the qualitative approach was applied. The qualitative research entailed an interpretive approach associated with using grounded theory and content analysis for interpreting data. The comparative case study design was the main qualitative research instrument for the multiple-case studies on emerging ostrich farmers in the Eastern Cape. The study was undertaken at five different sites, namely, the Peddie Ostrich Programme, the Rockhurst Ostrich Programme, the Hlumani Co-operative farm, the Zamukwanda Ostrich farm near Pearston and the Mimosadale Ostrich farm. The quantitative methods were applied to capture all the measurable components and representations of the stakeholders and participants, through interviews, questionnaires and focus group interviews. The quantitative study also included an experimental instrument to measure the capacity of emerging farmer programmes for supply chain participation. It was found that the main driver for three of the case studies pertained to land ownership and that ostrich farming was incidental and only seen as means of activity for income. These three humanitarian farming projects had limited capacity for intensive management requirements for ostrich farming. It was found that the VPN04 bio-security protocols and disease control require a higher level of record keeping for EU markets and is prohibitively expensive for poor rural emerging farmers. The study established that the emerging ostrich farming programmes contributed value to the industry and government rural development in land redistribution programmes, vehicles for reduction of poverty and job creation in the rural areas and by acting as out-grower programmes for commercial farmers. The researcher’s observation is that through strategic interventions the programmes have potential to become commercial players in the industry. The following interventions were recommended from this study: Feasibility study of programmes and review of location selection before initiation. Providing supportive interventions for programme start-ups; Improved selection of programme beneficiaries; Improved structure of emerging farmers’ co-operatives; On-going and appropriate training for emerging ostrich farmers; The role of government and mentors needs to be defined; Reducing feed costs; Establishing programmes linkages to informal markets and facilitating increased self-consumption; Developing new export markets; Alternative finance for the no-income months; Alternative marketing channels to export markets; Representation of emerging farmers in the ostrich-industry leadership structures.
- Full Text:
- Date Issued: 2013
- Authors: Pittaway, Timothy
- Date: 2013
- Subjects: Farmers -- South Africa -- Eastern Cape , Ostrich products industry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10596 , http://hdl.handle.net/10948/d1021008
- Description: The changing agricultural environment (dualistic agricultural landscape, land reform programme, market liberalisation and globalisation) has caused emerging ostrich farmers to become increasingly isolated. Governmental agriculture reforms and public sector interventions have been insufficient to address all the challenges faced by rural ostrich farmers in the Eastern Cape. Participation in the ostrich supply chain for emerging farmers in the Eastern Cape is currently unsustainable as a result of avian influenza, control and registration protocols for ostriches (VPN04), structural barriers in marketing, technical constraints and a lack of market participation. People in the rural areas of the Eastern Cape are challenged by inferior infrastructure, poor site conditions, low earnings, poor access to health services and unreliable water sources. The marginal conditions and prevalent complexities in which agriculture is practised require costly resource intervention. Intensive ostrich production necessitates continuous genetic improvement, methodical record keeping, intensive egg incubation methods and highmaintenance chick rearing and ostrich handling while minimising feed costs throughout this process. Rural farmers have not embraced ostrich farming in the same way as they have done with other livestock farming because it does not offer the anthropological functions that traditional livestock farming provides. The ostrich supply chain requires a wide range of activities to bring products to the final consumer. The worth of ostrich production lies mainly in the higher returns which are achieved only through the export markets. Today the ostrich industry has become vulnerable to market cannibalism, a lack of market development, unregulated numbers of ostriches and recurring international meat bans. The deregulation of the ostrich single-channel marketing system had a substantial effect on the value chain on which farmers depended for market access and market protection. As the majority of ostrich products are being exported to the European Union, the role of intermediary agencies is becoming an important factor influencing entry into the high-end markets. This agent structure that represents the South African ostrich industry is vital for the distribution, market penetration and regulation of the ostrich products. The ostrich leather, which is today the main product line, is primarily used for luxury goods and is susceptible to economic downturn and over-supply. The ostrich meat industry has been severely influenced by outbreaks of avian influenza and processors now pre-heat the meat in order to maintain export. However, this preheating meat facility is only for export produce and available to farmers who conform to VPN04 and have officially registered farms. The relevant South African government departments played a crucial role in identifying avian influenza outbreaks and liaising with the European Union about avian influenza isolation strategies. No previous studies have been conducted on the participation of emerging farmers in the Eastern Cape ostrich-industry supply chain and on the interventions required to address the multiple constraints and forces in this sector. This led to a study with research emphasis on the required capacity for supply-chain participation and the supporting mechanisms that would be required for emerging ostrich farmers to integrate successfully into this supply chain. An exploratory research approach was chosen for the investigation, as no earlier research has been undertaken that could serve as a source of reliable data or reference. A triangulation research methodology using both the quantitative and the qualitative approach was applied. The qualitative research entailed an interpretive approach associated with using grounded theory and content analysis for interpreting data. The comparative case study design was the main qualitative research instrument for the multiple-case studies on emerging ostrich farmers in the Eastern Cape. The study was undertaken at five different sites, namely, the Peddie Ostrich Programme, the Rockhurst Ostrich Programme, the Hlumani Co-operative farm, the Zamukwanda Ostrich farm near Pearston and the Mimosadale Ostrich farm. The quantitative methods were applied to capture all the measurable components and representations of the stakeholders and participants, through interviews, questionnaires and focus group interviews. The quantitative study also included an experimental instrument to measure the capacity of emerging farmer programmes for supply chain participation. It was found that the main driver for three of the case studies pertained to land ownership and that ostrich farming was incidental and only seen as means of activity for income. These three humanitarian farming projects had limited capacity for intensive management requirements for ostrich farming. It was found that the VPN04 bio-security protocols and disease control require a higher level of record keeping for EU markets and is prohibitively expensive for poor rural emerging farmers. The study established that the emerging ostrich farming programmes contributed value to the industry and government rural development in land redistribution programmes, vehicles for reduction of poverty and job creation in the rural areas and by acting as out-grower programmes for commercial farmers. The researcher’s observation is that through strategic interventions the programmes have potential to become commercial players in the industry. The following interventions were recommended from this study: Feasibility study of programmes and review of location selection before initiation. Providing supportive interventions for programme start-ups; Improved selection of programme beneficiaries; Improved structure of emerging farmers’ co-operatives; On-going and appropriate training for emerging ostrich farmers; The role of government and mentors needs to be defined; Reducing feed costs; Establishing programmes linkages to informal markets and facilitating increased self-consumption; Developing new export markets; Alternative finance for the no-income months; Alternative marketing channels to export markets; Representation of emerging farmers in the ostrich-industry leadership structures.
- Full Text:
- Date Issued: 2013
High performance nonwovens in technical textile applications
- Ogunleye, Christopher Olarinde
- Authors: Ogunleye, Christopher Olarinde
- Date: 2013
- Subjects: Nonwoven fabrics , Textile fabrics -- Technological innovations
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10356 , http://hdl.handle.net/10948/d1021011
- Description: The aim of this research was to establish the optimum processing conditions and parameters for producing nonwoven fabrics best suited for application in disposable and protective wear for surgical gowns, drapes and laboratory coats. Carded and crosslapped webs, of three basic weights (80, 120, and 150g/m2), from greige (unscoured and unbleached) cotton, viscose and polyester fibres, were hydroentangled, using three different waterjet pressures (60, 100 and 120 bars), on a Fleissner Aquajet hydroentanglement machine. An antibacterial agent (Ruco-Coat FC 9005) and a fluorochemical water repellent agent (Ruco Bac-AGP), were applied in one bath using the pad-dry-cure technique, to impart both antibacterial and water repellent properties to the fabrics, SEM photomicrographs indicating that the finished polymers were evenly dispersed on the fabric surface. The effect of waterjet pressure, fabric weight and type and treatment on the structure of the nonwoven produced, was evaluated by measuring the relevant characteristics of the fabrics. As expected, there was an interrelationship between fabric weight, thickness, and density, the fabric thickness and mass density increasing with fabric weight. An increase in waterjet pressure decreased the fabric thickness and increased the fabric density. The water repellent and antibacterial treatment increased the fabric weight and thickness. The antimicrobial activity of the fabrics was assessed by determining the percentage reduction in Staphylococcus aureus and Escherichia coli bacteria population. The maximum percent reduction at 24hrs contact time for both bacteria ranged from 99.5 to 99.6 percent for all the fabric types. The standard spray test ratings for the three treated fabrics ranged from 80-90 percent, whereas that of the untreated water repellent fabric was zero, while the contact angles for all the fabric types exceeded 90 degrees, indicating good resistance to wetting. It was found that the tensile strength of the fabric in the cross-machine direction was higher than that in the machine direction, for both the treated and untreated fabrics, with the tensile strengths in both the MD and CD of the treated fabrics were greater than that of the untreated fabrics, the reverse being true for the extension at break. An increase in waterjet pressure increased the tensile strength but decreased the extension at break, for both the treated and untreated fabrics. The finishing treatment decreased the mean pore size of all the fabrics, the mean pore size decreasing with an increase in fabric weight and waterjet pressure. An increase in waterjet pressure and fabric weight decreased the air and water vapour permeability, as did the finishing treatment, although the differences were not always statistically significant. The polyester fabrics had the highest water and air permeability. Hence low weight fabrics of 80 g/m2, which were hydroentangled at low water jet pressures of 60 bars, were suitable for use in this study due to their higher air and water vapour permeability as well as higher pore size distribution. These group of fabrics thus meet the requirements for surgical gowns, drapes, nurses’ uniforms and laboratory coats.
- Full Text:
- Date Issued: 2013
- Authors: Ogunleye, Christopher Olarinde
- Date: 2013
- Subjects: Nonwoven fabrics , Textile fabrics -- Technological innovations
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10356 , http://hdl.handle.net/10948/d1021011
- Description: The aim of this research was to establish the optimum processing conditions and parameters for producing nonwoven fabrics best suited for application in disposable and protective wear for surgical gowns, drapes and laboratory coats. Carded and crosslapped webs, of three basic weights (80, 120, and 150g/m2), from greige (unscoured and unbleached) cotton, viscose and polyester fibres, were hydroentangled, using three different waterjet pressures (60, 100 and 120 bars), on a Fleissner Aquajet hydroentanglement machine. An antibacterial agent (Ruco-Coat FC 9005) and a fluorochemical water repellent agent (Ruco Bac-AGP), were applied in one bath using the pad-dry-cure technique, to impart both antibacterial and water repellent properties to the fabrics, SEM photomicrographs indicating that the finished polymers were evenly dispersed on the fabric surface. The effect of waterjet pressure, fabric weight and type and treatment on the structure of the nonwoven produced, was evaluated by measuring the relevant characteristics of the fabrics. As expected, there was an interrelationship between fabric weight, thickness, and density, the fabric thickness and mass density increasing with fabric weight. An increase in waterjet pressure decreased the fabric thickness and increased the fabric density. The water repellent and antibacterial treatment increased the fabric weight and thickness. The antimicrobial activity of the fabrics was assessed by determining the percentage reduction in Staphylococcus aureus and Escherichia coli bacteria population. The maximum percent reduction at 24hrs contact time for both bacteria ranged from 99.5 to 99.6 percent for all the fabric types. The standard spray test ratings for the three treated fabrics ranged from 80-90 percent, whereas that of the untreated water repellent fabric was zero, while the contact angles for all the fabric types exceeded 90 degrees, indicating good resistance to wetting. It was found that the tensile strength of the fabric in the cross-machine direction was higher than that in the machine direction, for both the treated and untreated fabrics, with the tensile strengths in both the MD and CD of the treated fabrics were greater than that of the untreated fabrics, the reverse being true for the extension at break. An increase in waterjet pressure increased the tensile strength but decreased the extension at break, for both the treated and untreated fabrics. The finishing treatment decreased the mean pore size of all the fabrics, the mean pore size decreasing with an increase in fabric weight and waterjet pressure. An increase in waterjet pressure and fabric weight decreased the air and water vapour permeability, as did the finishing treatment, although the differences were not always statistically significant. The polyester fabrics had the highest water and air permeability. Hence low weight fabrics of 80 g/m2, which were hydroentangled at low water jet pressures of 60 bars, were suitable for use in this study due to their higher air and water vapour permeability as well as higher pore size distribution. These group of fabrics thus meet the requirements for surgical gowns, drapes, nurses’ uniforms and laboratory coats.
- Full Text:
- Date Issued: 2013
Improving decision making through analysing the economic impact of budget allocation at the city of Cape Town
- Authors: Kaiser, Gisela Noelle
- Date: 2013
- Subjects: Cape Town (South Africa) -- Politics and government , City planning -- South Africa --Cape Town , Budget -- South Africa -- Cape Town , Local government
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9684 , http://hdl.handle.net/10948/d1008305 , Cape Town (South Africa) -- Politics and government , City planning -- South Africa --Cape Town , Budget -- South Africa -- Cape Town , Local government
- Description: Local government is at the forefront of engagement between the government and South Africa’s people, delivering basic services to communities. Following the transition to a democratic government in 1994, the country was demarcated in a manner that provides complete coverage by local government. Annually, managing the administration of service delivery implementation at local government level costs the country many billions. Much of the revenue used by local government in providing services is derived from income from sale of basic services and property rates, augmented by allocations from national and provincial government, equitably shared amongst municipalities. Local government has autonomy in its operations, but is strictly governed by a collection of cascading legislation, introduced to protect the interests of the people. The primary objective of the research was to investigate the efficacy of budget expenditure in local government, in particular the City of Cape Town as a metropolitan municipality. With an annual budget approaching R30 billion, the aim was to establish how the budget was determined and allocated to the service menu provided by the City, and to investigate whether better methods of allocating expenditure could be developed. A mixed research methodology was followed, relying on quantitative methods for analysing survey data statistically, while providing for detailed qualitative methods in interviewing and studying the specific case in detail. The theoretical perspective most suited to this research was found to be that of pragmatism, for its flexibility of interpretation, practicality and space for multiple perspectives. A constructivist epistemology was adopted to provide for the interplay between object and subject in constructing meaning. This research focused on examination of applicable legislation, secondary data in reports, and statistical analysis of opinion surveys of municipal officials involved in budgeting at different levels and interviews with key stakeholders. The findings indicate that budget allocation can be improved upon in a number of ways, despite complying with a myriad of restrictive and onerous regulations applicable to local government. It was found that the administration is fragmented in its operations and that the structure of necessity favours isolated service delivery rather than integration. Further, that compliance impacts negatively on time spent in planning and pursuit of strategic intent to the extent that Reporting often becomes a more important deliverable than basic services. The size of the City hinders common understanding, and introducing any change in political vision requires particular attention.
- Full Text:
- Date Issued: 2013
- Authors: Kaiser, Gisela Noelle
- Date: 2013
- Subjects: Cape Town (South Africa) -- Politics and government , City planning -- South Africa --Cape Town , Budget -- South Africa -- Cape Town , Local government
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9684 , http://hdl.handle.net/10948/d1008305 , Cape Town (South Africa) -- Politics and government , City planning -- South Africa --Cape Town , Budget -- South Africa -- Cape Town , Local government
- Description: Local government is at the forefront of engagement between the government and South Africa’s people, delivering basic services to communities. Following the transition to a democratic government in 1994, the country was demarcated in a manner that provides complete coverage by local government. Annually, managing the administration of service delivery implementation at local government level costs the country many billions. Much of the revenue used by local government in providing services is derived from income from sale of basic services and property rates, augmented by allocations from national and provincial government, equitably shared amongst municipalities. Local government has autonomy in its operations, but is strictly governed by a collection of cascading legislation, introduced to protect the interests of the people. The primary objective of the research was to investigate the efficacy of budget expenditure in local government, in particular the City of Cape Town as a metropolitan municipality. With an annual budget approaching R30 billion, the aim was to establish how the budget was determined and allocated to the service menu provided by the City, and to investigate whether better methods of allocating expenditure could be developed. A mixed research methodology was followed, relying on quantitative methods for analysing survey data statistically, while providing for detailed qualitative methods in interviewing and studying the specific case in detail. The theoretical perspective most suited to this research was found to be that of pragmatism, for its flexibility of interpretation, practicality and space for multiple perspectives. A constructivist epistemology was adopted to provide for the interplay between object and subject in constructing meaning. This research focused on examination of applicable legislation, secondary data in reports, and statistical analysis of opinion surveys of municipal officials involved in budgeting at different levels and interviews with key stakeholders. The findings indicate that budget allocation can be improved upon in a number of ways, despite complying with a myriad of restrictive and onerous regulations applicable to local government. It was found that the administration is fragmented in its operations and that the structure of necessity favours isolated service delivery rather than integration. Further, that compliance impacts negatively on time spent in planning and pursuit of strategic intent to the extent that Reporting often becomes a more important deliverable than basic services. The size of the City hinders common understanding, and introducing any change in political vision requires particular attention.
- Full Text:
- Date Issued: 2013
Investigation into causes of service delivery protests in municipalities :a case study of Nelson Mandela Bay Municipality
- Authors: Shaidi, Elisante Walter
- Date: 2013
- Subjects: Municipal government|zSouth Africa -- Port Elizabeth , Municipal government
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:8245 , http://hdl.handle.net/10948/d1011153 , Municipal government|zSouth Africa -- Port Elizabeth , Municipal government
- Description: This study investigates the causes of the service delivery protests in South African municipalities that occurred between 2005 to 2013. In a sense, the recent widespread service delivery protests which, in many instances, have turned violent, have sounded an alarm that cannot be ignored. The study is premised on the fact that no political democracy can survive and flourish if the mass of its people remain in poverty, and in a state of inequality and unemployed without tangible prospects for a better life. In this regard, the presence of service delivery protests, especially violent ones, is a threat to South Africa’s young democracy and its sustainability. This study is based on the assumption that the Nelson Mandela Bay Metropolitan Municipality, like other municipalities in South Africa, could be confronted with the possibility of further violent service delivery protests if the current causes were not scientifically investigated and solutions found. The study adopted a hypothesis with a view that South African municipalities could succeed in rendering effective public services if matters of poor public participation, corruption, service delivery inhibiting systemic factors, a cumbersome legislative environment, political infighting, poor intergovernmental fiscal regime and the low capacity of municipalities were adequately addressed. The study proposed to provide a brief literature review on the emergence of service delivery protests against the backdrop of a theoretical investigation on the new local government developmental mandate. The empirical survey and research methodology employed in the study is described, followed by the operationalisation of the survey questionnaire used for gathering field data. The research findings of the empirical survey are then statistically analysed, interpreted and reported. Some of the findings on the causes of service delivery protests includes slow pace of service delivery, especially in the delivery of sustainable human settlements, poor public participation and other underpinning systemic factors. Recommendations flowing from, inter alia, the results of the empirical study, are presented on how the existing status quo can be changed to enhance service delivery and development. If adopted, these recommendations will enable the Nelson Mandela Bay Municipality, as a development agent, to fulfil its developmental mandate thereby addressing the causes of the service delivery protests currently facing it.
- Full Text:
- Date Issued: 2013
- Authors: Shaidi, Elisante Walter
- Date: 2013
- Subjects: Municipal government|zSouth Africa -- Port Elizabeth , Municipal government
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:8245 , http://hdl.handle.net/10948/d1011153 , Municipal government|zSouth Africa -- Port Elizabeth , Municipal government
- Description: This study investigates the causes of the service delivery protests in South African municipalities that occurred between 2005 to 2013. In a sense, the recent widespread service delivery protests which, in many instances, have turned violent, have sounded an alarm that cannot be ignored. The study is premised on the fact that no political democracy can survive and flourish if the mass of its people remain in poverty, and in a state of inequality and unemployed without tangible prospects for a better life. In this regard, the presence of service delivery protests, especially violent ones, is a threat to South Africa’s young democracy and its sustainability. This study is based on the assumption that the Nelson Mandela Bay Metropolitan Municipality, like other municipalities in South Africa, could be confronted with the possibility of further violent service delivery protests if the current causes were not scientifically investigated and solutions found. The study adopted a hypothesis with a view that South African municipalities could succeed in rendering effective public services if matters of poor public participation, corruption, service delivery inhibiting systemic factors, a cumbersome legislative environment, political infighting, poor intergovernmental fiscal regime and the low capacity of municipalities were adequately addressed. The study proposed to provide a brief literature review on the emergence of service delivery protests against the backdrop of a theoretical investigation on the new local government developmental mandate. The empirical survey and research methodology employed in the study is described, followed by the operationalisation of the survey questionnaire used for gathering field data. The research findings of the empirical survey are then statistically analysed, interpreted and reported. Some of the findings on the causes of service delivery protests includes slow pace of service delivery, especially in the delivery of sustainable human settlements, poor public participation and other underpinning systemic factors. Recommendations flowing from, inter alia, the results of the empirical study, are presented on how the existing status quo can be changed to enhance service delivery and development. If adopted, these recommendations will enable the Nelson Mandela Bay Municipality, as a development agent, to fulfil its developmental mandate thereby addressing the causes of the service delivery protests currently facing it.
- Full Text:
- Date Issued: 2013
M-health user experience framework for the public healthcare sector
- Authors: Ouma, Stella
- Date: 2013
- Subjects: Communication in public health , Public health -- South Africa , Wireless communication systems in medical care
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9827 , http://hdl.handle.net/10948/d1020793
- Description: The public healthcare sectors within developing nations face a lot of challenges because of constrained resources available to them. The South African public healthcare sector is no different. Although it serves the majority of the South African population, most of the financial resources are directed towards the private sector, which serves very few individuals when compared to the public healthcare sector. Apart from that, other challenges that the National Department of Health has to deal with include the lack of sufficiently trained healthcare employees who can work on the different levels of the public healthcare sector, as well as the burden of diseases such as HIV and Aids, tuberculosis and other chronic diseases. In order to improve service delivery, the National Department of Health is introducing Information and Communications Technology interventions that can increase efficiency and reduce costs, thereby improving the quality of service delivery. This research delivers an m-health application user experience framework to be proposed to the National Department of Health in South Africa, in order to assist in scaling up of m-health applications. The m-health applications that can benefit the South African population if scaled up successfully include those that can be used in remote data collection, treatment and compliance, accessing patients records, remote monitoring, communication and training for healthcare workers and applications that can be used for education and awareness. The study focused on three domains: the Human-Computer Interaction domain, public healthcare domain and Health Informatics domain. The proposed framework was realized by investigating mobile user experience components, mobile health requirements and the South African public healthcare domain components that contribute to the m-health user experience framework. This research was conducted through the interpretivist philosophy. Due to the exploratory nature of the study, an application of qualitative methodology was used. The conceptual theoretical framework was validated through a single case study approach by m-health user experience experts, who reside in South Africa. Data were analysed inductively. An m-health user experience framework was provided at the end of the study. An m-health user experience framework can assist the National Department of Health to look into design issues, address m-health requirements and put the domain needs in place, thus enabling the Department to successfully scale up implementations of m-health applications nationwide.
- Full Text:
- Date Issued: 2013
- Authors: Ouma, Stella
- Date: 2013
- Subjects: Communication in public health , Public health -- South Africa , Wireless communication systems in medical care
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9827 , http://hdl.handle.net/10948/d1020793
- Description: The public healthcare sectors within developing nations face a lot of challenges because of constrained resources available to them. The South African public healthcare sector is no different. Although it serves the majority of the South African population, most of the financial resources are directed towards the private sector, which serves very few individuals when compared to the public healthcare sector. Apart from that, other challenges that the National Department of Health has to deal with include the lack of sufficiently trained healthcare employees who can work on the different levels of the public healthcare sector, as well as the burden of diseases such as HIV and Aids, tuberculosis and other chronic diseases. In order to improve service delivery, the National Department of Health is introducing Information and Communications Technology interventions that can increase efficiency and reduce costs, thereby improving the quality of service delivery. This research delivers an m-health application user experience framework to be proposed to the National Department of Health in South Africa, in order to assist in scaling up of m-health applications. The m-health applications that can benefit the South African population if scaled up successfully include those that can be used in remote data collection, treatment and compliance, accessing patients records, remote monitoring, communication and training for healthcare workers and applications that can be used for education and awareness. The study focused on three domains: the Human-Computer Interaction domain, public healthcare domain and Health Informatics domain. The proposed framework was realized by investigating mobile user experience components, mobile health requirements and the South African public healthcare domain components that contribute to the m-health user experience framework. This research was conducted through the interpretivist philosophy. Due to the exploratory nature of the study, an application of qualitative methodology was used. The conceptual theoretical framework was validated through a single case study approach by m-health user experience experts, who reside in South Africa. Data were analysed inductively. An m-health user experience framework was provided at the end of the study. An m-health user experience framework can assist the National Department of Health to look into design issues, address m-health requirements and put the domain needs in place, thus enabling the Department to successfully scale up implementations of m-health applications nationwide.
- Full Text:
- Date Issued: 2013
Microcystin enhances the fitness of microcystin producing cyanobacteria at high light intensities by either preventing or retarding photoinhibition
- Authors: Phelan, Richard Reginald
- Date: 2013
- Subjects: Microcystins , Microcystis , Cyanobacterial toxins
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10354 , http://hdl.handle.net/10948/d1020957
- Description: Several genera of cyanobacteria produce microcystin, a monocyclic peptide, with a unique chemical structure. To date, there have been over a 100 different structural variants of microcystin which have been identified. Microcystin production is affected by numerous environmental factors. However, the primary modulating factor for intracellular microcystin quota is the intracellular N:C ratio. No clearly defined biological role has been described for microcystin. Proposed roles for microcystin include defence against plankton grazers, metal chelation, an infochemical and a protectant against oxidative stress. There is sufficient evidence to support a biological role for microcystin in photosynthesis: microcystin is predominantly located in the thylakoid membranes, the microcystin gene cluster is differentially expressed as a function of light and a growth advantage for the microcystin producer in saturating light intensities. The purpose of this study is to investigate a possible biological role for microcystin in preventing photoinhibition and thus explaining the growth advantage observed in toxin-producers over non-toxin-producers. The uptake of exogenous microcystin was observed in Synechocystis PCC 6803 which was internalized and located in the thylakoid membranes and caused the inhibition of photosynthesis. Microcystin variants and increasing concentrations of microcystin-LR had no effect on the fluidity of the thylakoid membranes. The exposure of thylakoid membranes from Synechocystis PCC 6803 to physiologically relevant concentrations of different microcystin variants resulted in the inhibition of photosystem II activity but not photosystem I activity. The inhibition of photosystem II was variant dependent and concentration dependent for microcystin-LR and microcystin-RR. Chlorophyll a fluorescence data showed that photosystem II inhibition was caused by the inhibition of the oxygen evolving complex. Furthermore, a completion study revealed that the microcystin-producing Microcystis PCC 7806 had a competitive advantage over the non-microcystin producing ΔmcyA mutant of Microcystis PCC 7806 at high light intensities. The data indicates that microcystin protects the toxin-producer by either retarding or preventing photoinhibition and thus identifying the first data supported function for microcystin in cyanobacteria.
- Full Text:
- Date Issued: 2013
- Authors: Phelan, Richard Reginald
- Date: 2013
- Subjects: Microcystins , Microcystis , Cyanobacterial toxins
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10354 , http://hdl.handle.net/10948/d1020957
- Description: Several genera of cyanobacteria produce microcystin, a monocyclic peptide, with a unique chemical structure. To date, there have been over a 100 different structural variants of microcystin which have been identified. Microcystin production is affected by numerous environmental factors. However, the primary modulating factor for intracellular microcystin quota is the intracellular N:C ratio. No clearly defined biological role has been described for microcystin. Proposed roles for microcystin include defence against plankton grazers, metal chelation, an infochemical and a protectant against oxidative stress. There is sufficient evidence to support a biological role for microcystin in photosynthesis: microcystin is predominantly located in the thylakoid membranes, the microcystin gene cluster is differentially expressed as a function of light and a growth advantage for the microcystin producer in saturating light intensities. The purpose of this study is to investigate a possible biological role for microcystin in preventing photoinhibition and thus explaining the growth advantage observed in toxin-producers over non-toxin-producers. The uptake of exogenous microcystin was observed in Synechocystis PCC 6803 which was internalized and located in the thylakoid membranes and caused the inhibition of photosynthesis. Microcystin variants and increasing concentrations of microcystin-LR had no effect on the fluidity of the thylakoid membranes. The exposure of thylakoid membranes from Synechocystis PCC 6803 to physiologically relevant concentrations of different microcystin variants resulted in the inhibition of photosystem II activity but not photosystem I activity. The inhibition of photosystem II was variant dependent and concentration dependent for microcystin-LR and microcystin-RR. Chlorophyll a fluorescence data showed that photosystem II inhibition was caused by the inhibition of the oxygen evolving complex. Furthermore, a completion study revealed that the microcystin-producing Microcystis PCC 7806 had a competitive advantage over the non-microcystin producing ΔmcyA mutant of Microcystis PCC 7806 at high light intensities. The data indicates that microcystin protects the toxin-producer by either retarding or preventing photoinhibition and thus identifying the first data supported function for microcystin in cyanobacteria.
- Full Text:
- Date Issued: 2013
Molecular signaling in colorectal carcinogenesis : the roles and relationships of beta-catenin, PPARgamma and COX-2
- Authors: Fredericks, Ernst
- Date: 2013
- Subjects: Colon (Anatomy) -- Cancer , Cyclooxygenase 2 , Peroxisomes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10357 , http://hdl.handle.net/10948/d1021014
- Description: Colorectal cancer (CRC) is a common disease with significant morbidity and mortality. In spite of significant advances in understanding the molecular signaling in this disorder, unanswered questions remain. Cyclooxygenase-2 (COX-2) and β-catenin have established roles in colorectal carcinogenesis, with both being upregulated early in the disease course. The role of peroxisome proliferator-activated receptor γ (PPARγ) is less clear, but has been shown to be downregulated in colon cancer models. Butyrate, a short chain fatty acid, produced by colon microbiota and transported into the colonocyte by transporter proteins, appears to be important in early carcinogenesis. The butyrate concentration is reduced in CRC and so are its transporters. Interleukin-17 (IL-17) plays a role in colitis-associated colorectal cancer (CAC), but its function in sporadic CRC is less clear. Similarly, Protein kinase C (PKC) has proven involvement in many solid tumours, including CRC, but its exact mechanistic role is still speculative. AIM: To investigate the role and possible signaling pathways of the major role players, β-catenin, COX-2 and PPARγ in early CRC. Further, to elucidate the mechanistic pathways of butyrate and its transporters, IL-17 and PKC in CRC. METHOD: Informed consent was obtained for all patients. Patients were recruited in various disease categories, including normal, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) and CRC. Colon biopsy specimens were obtained during colonoscopy and used for immunohistochemistry (IHC) and gene expression analysis of the above genes by quantitative polymerase chain reaction (qPCR). RESULTS: β-catenin mRNA and protein expression was increased in CRC and the IBD groups compared to the normal group, while it was reduced in the IBS groups. COX-2 mRNA expression showed a steady increase from normal, through IBS, IBD and CRC groups to a statistically significant degree. The COX-2 protein expression, however, did not match the mRNA expression with increased COX-2 protein expression in normal and IBS groups and reduced expression in IBD and CRC groups. PPARγ mRNA expression was unchanged in IBD and CRC groups, but significantly increased in the IBS group compared to normal. Butyrate transporter, SLC16A1 mRNA was significantly reduced in CRC, but also in the IBS groups, which was unexpected. In the IBD group, SLC16A1 mRNA was unchanged in Crohn’s disease (CD) but significantly reduced in ulcerative colitis (UC). Similarly, SLC5A8 mRNA expression was significantly reduced in the CRC as well as the IBS groups. In the IBD groups, SLC5A8 was unchanged in UC but significantly increased in CD. IL-17 mRNA expression was significantly reduced in CRC and IBS groups, but unchanged in the IBD groups. PKCε mRNA was significantly increased in CRC as expected. In the IBD groups, PKCε mRNA was unchanged in CD but significantly increased in UC. In the IBS groups, PKCε mRNA in constipation –IBS (C-IBS) was significantly reduced, but unchanged in diarrhoea – IBS (D-IBS). CONCLUSIONS: β-catenin mRNA and protein expression was increased in CRC and the CRC promoting IBD groups. COX-2 protein expression was incongruent with the COX-2 mRNA expression and this may reflect homeostatic control mechanisms. High COX-2 mRNA expression in CRC and CRC promoting IBD groups may be a secondary phenomenon reflecting the inflammatory milieu, rather than a true carcinogenesis-related event. PPARγ does not appear to play a central role in early colon carcinogenesis, in spite of available literature suggesting otherwise. Butyrate transporters showed inconsistent results and for now no firm conclusions can be drawn from this. IL-17 may play a role in CAC as confirmed in this and other studies, but its role in sporadic CRC is tenuous and requires further investigation. Likewise for PKCε, upregulation is associated with increased tumourigenecity as shown in this study, however, the mechanistic pathway(s) involved is still speculative and requires further study.
- Full Text:
- Date Issued: 2013
- Authors: Fredericks, Ernst
- Date: 2013
- Subjects: Colon (Anatomy) -- Cancer , Cyclooxygenase 2 , Peroxisomes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10357 , http://hdl.handle.net/10948/d1021014
- Description: Colorectal cancer (CRC) is a common disease with significant morbidity and mortality. In spite of significant advances in understanding the molecular signaling in this disorder, unanswered questions remain. Cyclooxygenase-2 (COX-2) and β-catenin have established roles in colorectal carcinogenesis, with both being upregulated early in the disease course. The role of peroxisome proliferator-activated receptor γ (PPARγ) is less clear, but has been shown to be downregulated in colon cancer models. Butyrate, a short chain fatty acid, produced by colon microbiota and transported into the colonocyte by transporter proteins, appears to be important in early carcinogenesis. The butyrate concentration is reduced in CRC and so are its transporters. Interleukin-17 (IL-17) plays a role in colitis-associated colorectal cancer (CAC), but its function in sporadic CRC is less clear. Similarly, Protein kinase C (PKC) has proven involvement in many solid tumours, including CRC, but its exact mechanistic role is still speculative. AIM: To investigate the role and possible signaling pathways of the major role players, β-catenin, COX-2 and PPARγ in early CRC. Further, to elucidate the mechanistic pathways of butyrate and its transporters, IL-17 and PKC in CRC. METHOD: Informed consent was obtained for all patients. Patients were recruited in various disease categories, including normal, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) and CRC. Colon biopsy specimens were obtained during colonoscopy and used for immunohistochemistry (IHC) and gene expression analysis of the above genes by quantitative polymerase chain reaction (qPCR). RESULTS: β-catenin mRNA and protein expression was increased in CRC and the IBD groups compared to the normal group, while it was reduced in the IBS groups. COX-2 mRNA expression showed a steady increase from normal, through IBS, IBD and CRC groups to a statistically significant degree. The COX-2 protein expression, however, did not match the mRNA expression with increased COX-2 protein expression in normal and IBS groups and reduced expression in IBD and CRC groups. PPARγ mRNA expression was unchanged in IBD and CRC groups, but significantly increased in the IBS group compared to normal. Butyrate transporter, SLC16A1 mRNA was significantly reduced in CRC, but also in the IBS groups, which was unexpected. In the IBD group, SLC16A1 mRNA was unchanged in Crohn’s disease (CD) but significantly reduced in ulcerative colitis (UC). Similarly, SLC5A8 mRNA expression was significantly reduced in the CRC as well as the IBS groups. In the IBD groups, SLC5A8 was unchanged in UC but significantly increased in CD. IL-17 mRNA expression was significantly reduced in CRC and IBS groups, but unchanged in the IBD groups. PKCε mRNA was significantly increased in CRC as expected. In the IBD groups, PKCε mRNA was unchanged in CD but significantly increased in UC. In the IBS groups, PKCε mRNA in constipation –IBS (C-IBS) was significantly reduced, but unchanged in diarrhoea – IBS (D-IBS). CONCLUSIONS: β-catenin mRNA and protein expression was increased in CRC and the CRC promoting IBD groups. COX-2 protein expression was incongruent with the COX-2 mRNA expression and this may reflect homeostatic control mechanisms. High COX-2 mRNA expression in CRC and CRC promoting IBD groups may be a secondary phenomenon reflecting the inflammatory milieu, rather than a true carcinogenesis-related event. PPARγ does not appear to play a central role in early colon carcinogenesis, in spite of available literature suggesting otherwise. Butyrate transporters showed inconsistent results and for now no firm conclusions can be drawn from this. IL-17 may play a role in CAC as confirmed in this and other studies, but its role in sporadic CRC is tenuous and requires further investigation. Likewise for PKCε, upregulation is associated with increased tumourigenecity as shown in this study, however, the mechanistic pathway(s) involved is still speculative and requires further study.
- Full Text:
- Date Issued: 2013
Monitoring carbon stocks in the sub-tropical thicket biome using remote sensing and GIS techniques : the case of the Great Fish River Nature Reserve and its environs, Eastern Cape province, South Africa
- Authors: Nyamugama, Adolph
- Date: 2013
- Subjects: Fragmented landscapes -- South Africa -- Eastern Cape -- Remote sensing , Environmental degradation -- South Africa -- Eastern Cape , Remote sensing , Geographic information systems
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10672 , http://hdl.handle.net/10948/d1020303
- Description: The subtropical thicket biome in the Eastern Cape Province of South Africa has been heavily degraded and transformed due overutilization during the last century. The highly degraded and transformed areas exhibit a significant loss of above ground carbon stocks (AGC) and loss of SOC content. Information about land use /cover change and fragmentation dynamics is a prerequisite for measuring carbon stock changes. The main aim of this study is to assess the trends of land use/cover change, fragmentation dynamics, model the temporal changes of AGC stocks in the Great Fish River Nature Reserve and its environs from 1972 to 2010, quantify and map the spatial distribution of SOC concentrations in the partial subtropical thicket cover in the Great Fish River Nature Reserve and environs (communal rangelands). Multi-temporal analyses based on 1972 Landsat MSS, 1982 and 1992 Landsat TM, 2002 Landsat ETM and 2010 SPOT 5 High Resolution images were used for land use/cover change detection and fragmentation analysis. Object oriented post-classification comparison was applied for land use/cover change detection analysis. Fragmentation dynamics analysis was carried out by computing and analyzing landscape metrics in land use/cover classes. Landscape fragmentation analyses revealed that thicket vegetation has increasingly become fragmented, characterized by smaller less linked patches of intact thicket cover. Landscape metrics for intact thicket and degraded thicket classes reflected fragmentation, as illustrated by the increase in the Number of Patches (NP), Patch Density (PD), Landscape Shape Index (LSI), and a decrease in Mean Patch Size (MPS). The use of remote sensing techniques and landscape metrics was vital for the understanding of the dynamics of land use/cover change and fragmentation. Baseline land use/cover maps produced for 1972, 1982, 1992 2002 and 2010 and fragmentation analyses were then used for analyzing carbon stock changes in the study area. To model the temporal changes of AGC stocks in the Great Fish River Nature Reserve and its environs from 1972 to 2010, a method based on the integration of RS and GIS was employed for the estimation of AGC stocks in a time series. A non-linear regression model was developed using NDVI values generated from SPOT 5 HRG satellite imagery of 2010 as the independent variable and AGC stock estimates from field plots as the dependent variable. The regression model was used to estimate AGC stocks for the entire study area on the 2010 SPOT 5 HRG and also extrapolated to the 1972 Landsat MSS, 1982 and 1992 Landsat TM, and 2002 Landsat ETM. The AGC stocks for the period 1972 -1982, 1982-1992, 1992-200) and 2002-2010 were compared by means of change detection analysis. The comparison of AGC stocks was carried out at subtropical thicket class level. The results showed a decline of AGC stocks in all the classes from 1972 to 2010. Degraded and transformed thicket classes had the highest AGC stock losses. The decline of AGC stocks was attributed to thicket transformation and degradation which were caused by anthropogenic activities. To map and quantify SOC concentration in partial (fractional) thicket vegetation cover, the spectral reflectance of both thicket vegetation and bare-soils was measured in situ. Soil samples were collected from the sampling sites and transported to the laboratory for spectral reflectance and SOC measurements. Thicket vegetation and bare soil reflectance were measured using spectroscopy both in situ and under laboratory conditions. Their respective endmembers were extracted from ASTER imagery using the Pixel Purity Index (PPI). The endmembers were validated with in situ and laboratory thicket and bare-soil reflectance signatures. The spectral unmixing technique was applied to ASTER imagery to discriminate pure pixels of thicket vegetation and bare-soils; a residual spectral image was produced. The Residual Spectral Unmixing (RSU) procedure was applied to the residual spectral image to produce an RSU soil spectrum image. Partial Least Squares Regression (PSLR) model was developed using spectral signatures of a residual soil spectrum image as the independent variable and SOC concentration measured from soil samples as the dependent variable. The PSLR prediction model was used to predict SOC concentration on the RSU soil spectral image. The predicted SOC concentration was then validated with SOC concentration measured from the field plots. A Strong correlation (R2 = 0.82) was obtained between the predicted SOC concentration and the SOC concentration measured from field samples. The PSLR was then used to generate a map of SOC concentration for the Great Fish River Nature Reserve and its environs. Areas with very low SOC concentrations were found in the degraded communal villages, as opposed to the higher SOC values in the protected area. The results confirmed that RS techniques are key to estimating and mapping the spatial distribution of SOC concentration in partial subtropical thicket vegetation. Partial thicket vegetation has a huge influence on the soil spectra; it can influence the prediction of SOC concentration. The use of the RSU approach eliminates partial thicket vegetation cover from bare soil spectra. The residual soil spectrum image contains enough information for the mapping of SOC concentration. The technique has the potential to augment the applicability of airborne imaging spectroscopy for soil studies in the sub-tropical thicket biome and similar environments.
- Full Text:
- Date Issued: 2013
- Authors: Nyamugama, Adolph
- Date: 2013
- Subjects: Fragmented landscapes -- South Africa -- Eastern Cape -- Remote sensing , Environmental degradation -- South Africa -- Eastern Cape , Remote sensing , Geographic information systems
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10672 , http://hdl.handle.net/10948/d1020303
- Description: The subtropical thicket biome in the Eastern Cape Province of South Africa has been heavily degraded and transformed due overutilization during the last century. The highly degraded and transformed areas exhibit a significant loss of above ground carbon stocks (AGC) and loss of SOC content. Information about land use /cover change and fragmentation dynamics is a prerequisite for measuring carbon stock changes. The main aim of this study is to assess the trends of land use/cover change, fragmentation dynamics, model the temporal changes of AGC stocks in the Great Fish River Nature Reserve and its environs from 1972 to 2010, quantify and map the spatial distribution of SOC concentrations in the partial subtropical thicket cover in the Great Fish River Nature Reserve and environs (communal rangelands). Multi-temporal analyses based on 1972 Landsat MSS, 1982 and 1992 Landsat TM, 2002 Landsat ETM and 2010 SPOT 5 High Resolution images were used for land use/cover change detection and fragmentation analysis. Object oriented post-classification comparison was applied for land use/cover change detection analysis. Fragmentation dynamics analysis was carried out by computing and analyzing landscape metrics in land use/cover classes. Landscape fragmentation analyses revealed that thicket vegetation has increasingly become fragmented, characterized by smaller less linked patches of intact thicket cover. Landscape metrics for intact thicket and degraded thicket classes reflected fragmentation, as illustrated by the increase in the Number of Patches (NP), Patch Density (PD), Landscape Shape Index (LSI), and a decrease in Mean Patch Size (MPS). The use of remote sensing techniques and landscape metrics was vital for the understanding of the dynamics of land use/cover change and fragmentation. Baseline land use/cover maps produced for 1972, 1982, 1992 2002 and 2010 and fragmentation analyses were then used for analyzing carbon stock changes in the study area. To model the temporal changes of AGC stocks in the Great Fish River Nature Reserve and its environs from 1972 to 2010, a method based on the integration of RS and GIS was employed for the estimation of AGC stocks in a time series. A non-linear regression model was developed using NDVI values generated from SPOT 5 HRG satellite imagery of 2010 as the independent variable and AGC stock estimates from field plots as the dependent variable. The regression model was used to estimate AGC stocks for the entire study area on the 2010 SPOT 5 HRG and also extrapolated to the 1972 Landsat MSS, 1982 and 1992 Landsat TM, and 2002 Landsat ETM. The AGC stocks for the period 1972 -1982, 1982-1992, 1992-200) and 2002-2010 were compared by means of change detection analysis. The comparison of AGC stocks was carried out at subtropical thicket class level. The results showed a decline of AGC stocks in all the classes from 1972 to 2010. Degraded and transformed thicket classes had the highest AGC stock losses. The decline of AGC stocks was attributed to thicket transformation and degradation which were caused by anthropogenic activities. To map and quantify SOC concentration in partial (fractional) thicket vegetation cover, the spectral reflectance of both thicket vegetation and bare-soils was measured in situ. Soil samples were collected from the sampling sites and transported to the laboratory for spectral reflectance and SOC measurements. Thicket vegetation and bare soil reflectance were measured using spectroscopy both in situ and under laboratory conditions. Their respective endmembers were extracted from ASTER imagery using the Pixel Purity Index (PPI). The endmembers were validated with in situ and laboratory thicket and bare-soil reflectance signatures. The spectral unmixing technique was applied to ASTER imagery to discriminate pure pixels of thicket vegetation and bare-soils; a residual spectral image was produced. The Residual Spectral Unmixing (RSU) procedure was applied to the residual spectral image to produce an RSU soil spectrum image. Partial Least Squares Regression (PSLR) model was developed using spectral signatures of a residual soil spectrum image as the independent variable and SOC concentration measured from soil samples as the dependent variable. The PSLR prediction model was used to predict SOC concentration on the RSU soil spectral image. The predicted SOC concentration was then validated with SOC concentration measured from the field plots. A Strong correlation (R2 = 0.82) was obtained between the predicted SOC concentration and the SOC concentration measured from field samples. The PSLR was then used to generate a map of SOC concentration for the Great Fish River Nature Reserve and its environs. Areas with very low SOC concentrations were found in the degraded communal villages, as opposed to the higher SOC values in the protected area. The results confirmed that RS techniques are key to estimating and mapping the spatial distribution of SOC concentration in partial subtropical thicket vegetation. Partial thicket vegetation has a huge influence on the soil spectra; it can influence the prediction of SOC concentration. The use of the RSU approach eliminates partial thicket vegetation cover from bare soil spectra. The residual soil spectrum image contains enough information for the mapping of SOC concentration. The technique has the potential to augment the applicability of airborne imaging spectroscopy for soil studies in the sub-tropical thicket biome and similar environments.
- Full Text:
- Date Issued: 2013
Nonlinear effects with a focus on cross phase modulation and its impact on wavelength division multiplexing optical fibre networks
- Gamatham, Romeo Reginald Gunther
- Authors: Gamatham, Romeo Reginald Gunther
- Date: 2013
- Subjects: Wavelength division multiplexing , Optical communications , Fiber optics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/6302 , vital:21071
- Description: The demand for faster data transmission is ever increasing. Wavelength division multiplexing (WDM) presents as a viable solution to increase the data transmission rate significantly. WDM systems are based on the ability to transmit multiple wavelengths simultaneously down the fibre. Unlike time division multiplexing (TDM) systems, WDM systems do not increase the data transfer by increasing the transmission rate of a single channel. In WDM systems the data rate per channel remains the same, only multiple channels carry data across the link. Dense wavelength division multiplexing (DWDM) promises even more wavelengths packed together in the same fibre. This multiplication of channels increases the bandwidth capacity rapidly. Networks are looking into making use of technology that will ensure no electronic signal regeneration at any point within the DWDM network. Examples are; reconfigurable optical add/drop multiplexers (ROADM) and optical cross connect (OXC) units. These components essentially enable network operators to split, combine and multiplex optical signals carried by optical fibre. WDM allows network operators to increase the capacity of existing networks without expensive re-cabling. This provides networks with the flexibility to be upgraded to larger bandwidths and for reconfiguration of network services. Further, WDM technology opens up an opportunity of marketing flexibility to network operators, where operators not only have the option to rent out cables and fibres but wavelengths as well. Cross phase modulation (XPM) poses a problem to WDM networks. The refractive index experienced by a neighbouring optical signal, not only depends on the signal’s intensity but on the intensity of the co-propagating signal as well. This effect leads to a phase change and is known as XPM. This work investigates the characteristics of XPM. It is shown that, in a two channel WDM network, a probe signal’s SOP can be steered by controlling a high intensity pump signal’s SOP. This effect could be applied to make a wavelength converter. Experimental results show that the degree of polarization (DOP) of a probe signal degrades according to a mathematical model found in literature. The pump and probe signals are shown to experience maximum interaction, for orthogonal probe-pump SOP vector orientations. This may be problematic to polarization mode dispersion compensators. Additionally, experimental results point out that the SOP of a probe signal is much more active in the presence of a high intensity pump, as compared to the single signal transmission scenario.
- Full Text:
- Date Issued: 2013
- Authors: Gamatham, Romeo Reginald Gunther
- Date: 2013
- Subjects: Wavelength division multiplexing , Optical communications , Fiber optics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/6302 , vital:21071
- Description: The demand for faster data transmission is ever increasing. Wavelength division multiplexing (WDM) presents as a viable solution to increase the data transmission rate significantly. WDM systems are based on the ability to transmit multiple wavelengths simultaneously down the fibre. Unlike time division multiplexing (TDM) systems, WDM systems do not increase the data transfer by increasing the transmission rate of a single channel. In WDM systems the data rate per channel remains the same, only multiple channels carry data across the link. Dense wavelength division multiplexing (DWDM) promises even more wavelengths packed together in the same fibre. This multiplication of channels increases the bandwidth capacity rapidly. Networks are looking into making use of technology that will ensure no electronic signal regeneration at any point within the DWDM network. Examples are; reconfigurable optical add/drop multiplexers (ROADM) and optical cross connect (OXC) units. These components essentially enable network operators to split, combine and multiplex optical signals carried by optical fibre. WDM allows network operators to increase the capacity of existing networks without expensive re-cabling. This provides networks with the flexibility to be upgraded to larger bandwidths and for reconfiguration of network services. Further, WDM technology opens up an opportunity of marketing flexibility to network operators, where operators not only have the option to rent out cables and fibres but wavelengths as well. Cross phase modulation (XPM) poses a problem to WDM networks. The refractive index experienced by a neighbouring optical signal, not only depends on the signal’s intensity but on the intensity of the co-propagating signal as well. This effect leads to a phase change and is known as XPM. This work investigates the characteristics of XPM. It is shown that, in a two channel WDM network, a probe signal’s SOP can be steered by controlling a high intensity pump signal’s SOP. This effect could be applied to make a wavelength converter. Experimental results show that the degree of polarization (DOP) of a probe signal degrades according to a mathematical model found in literature. The pump and probe signals are shown to experience maximum interaction, for orthogonal probe-pump SOP vector orientations. This may be problematic to polarization mode dispersion compensators. Additionally, experimental results point out that the SOP of a probe signal is much more active in the presence of a high intensity pump, as compared to the single signal transmission scenario.
- Full Text:
- Date Issued: 2013
Rural women's representation and participation in local governance in the Masvingo and Mashonaland central provinces of Zimbabwe
- Authors: Kurebwa, Jeffrey
- Date: 2013
- Subjects: Local government -- Women -- Zimbabwe , Public administration -- Citizen participation -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:8313 , http://hdl.handle.net/10948/d1020085
- Description: This study focused on the representation and participation of rural women in local governance in the Masvingo and Mashonaland Central provinces of Zimbabwe. It argued that increased representation and participation of women in local governance, particularly as ward councillors and senior administrative employees, is important and should be pursued. This has the potential to change the local governance system. The research further argued that change is more likely to occur when elected women are supported by the presence of more women at the most senior administrative levels in the local governance system. The presence of more women is required if the local governance system is to become inclusive of the diversity of the people it represents, especially women. This study rejected the assumption that rural women are passive recipients of local governance since they contribute significantly in fulfilling household and community needs and interests. Through their knowledge and understanding of the construction of power relations at the local level, rural women have creatively managed to produce, reproduce and use alternative strategies which are based on their sexuality and traditional gender roles in challenging and transforming gender inequality at the local level and in improving the quality of rural women. A National Gender Management System (NGMS) that can be used to effectively promote gender equity, equality and justice in local authorities has been developed. It is desirable that the NGMS be established within the existing organisational framework of central and local governments in Zimbabwe. This should be connected to the national structures to ensure that local level activities are systematically accounted for at the national level. The NGMS recognises the strategic importance of building partnerships with social actors at all levels. Qualitative research method was used in the study. The study used both primary and secondary data in analysing the representation and participation of rural women in local governance in the two selected provinces in Zimbabwe, namely Masvingo and Mashonaland Central. Primary data was collected through in-depth interviews and survey questionnaires, while secondary data was gathered through a literature survey of relevant textbooks, newspapers, and peer-reviewed journals, reports and legislation. The research findings indicated that rural women face a number of constraints in getting access to and participating in local governance. Some of the constraints include; cultural beliefs; violence against women; lack of resources; lack of mutual support among women; domestic responsibilities; and institutional factors. The contributions of the research to the study of women in local governance are discussed. Recommendations to increase the participation of women in local governance are made. These include creating an enabling environment for women’s political empowerment, gender-responsive budgets, capacity-building programmes, establishment of gender focal points, gender management committees and teams, increasing women’s self-worth and changing perceptions by men. The study also found that decentralisation in Zimbabwe has not brought local governance closer to rural women due to the interweaving cultural, structural, physical and financial barriers local government faces in ensuring gender equality.
- Full Text:
- Date Issued: 2013
- Authors: Kurebwa, Jeffrey
- Date: 2013
- Subjects: Local government -- Women -- Zimbabwe , Public administration -- Citizen participation -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:8313 , http://hdl.handle.net/10948/d1020085
- Description: This study focused on the representation and participation of rural women in local governance in the Masvingo and Mashonaland Central provinces of Zimbabwe. It argued that increased representation and participation of women in local governance, particularly as ward councillors and senior administrative employees, is important and should be pursued. This has the potential to change the local governance system. The research further argued that change is more likely to occur when elected women are supported by the presence of more women at the most senior administrative levels in the local governance system. The presence of more women is required if the local governance system is to become inclusive of the diversity of the people it represents, especially women. This study rejected the assumption that rural women are passive recipients of local governance since they contribute significantly in fulfilling household and community needs and interests. Through their knowledge and understanding of the construction of power relations at the local level, rural women have creatively managed to produce, reproduce and use alternative strategies which are based on their sexuality and traditional gender roles in challenging and transforming gender inequality at the local level and in improving the quality of rural women. A National Gender Management System (NGMS) that can be used to effectively promote gender equity, equality and justice in local authorities has been developed. It is desirable that the NGMS be established within the existing organisational framework of central and local governments in Zimbabwe. This should be connected to the national structures to ensure that local level activities are systematically accounted for at the national level. The NGMS recognises the strategic importance of building partnerships with social actors at all levels. Qualitative research method was used in the study. The study used both primary and secondary data in analysing the representation and participation of rural women in local governance in the two selected provinces in Zimbabwe, namely Masvingo and Mashonaland Central. Primary data was collected through in-depth interviews and survey questionnaires, while secondary data was gathered through a literature survey of relevant textbooks, newspapers, and peer-reviewed journals, reports and legislation. The research findings indicated that rural women face a number of constraints in getting access to and participating in local governance. Some of the constraints include; cultural beliefs; violence against women; lack of resources; lack of mutual support among women; domestic responsibilities; and institutional factors. The contributions of the research to the study of women in local governance are discussed. Recommendations to increase the participation of women in local governance are made. These include creating an enabling environment for women’s political empowerment, gender-responsive budgets, capacity-building programmes, establishment of gender focal points, gender management committees and teams, increasing women’s self-worth and changing perceptions by men. The study also found that decentralisation in Zimbabwe has not brought local governance closer to rural women due to the interweaving cultural, structural, physical and financial barriers local government faces in ensuring gender equality.
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- Date Issued: 2013