Examining the teaching of natural sciences concepts to English second language speakers in selected primary schools in the East London Education District
- Authors: Kumanda, Nomaroma
- Date: 2019
- Subjects: Science -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15925 , vital:40564
- Description: The study sought to examine the teaching of Natural Sciences (NS) concepts to English second language speakers in selected primary schools. Grade 7 was chosen for the investigation as it precedes the last class at primary school. The researcher investigated the teaching and learning of Natural sciences concepts. A mixed method design was used. The research questions focused on the teaching of NS, learner-centred strategies used, challenges encountered, strategies employed by teachers when teaching NS, and the implications for science education.The purpose was to examine the teaching of Natural Sciences concepts to English second language speakers in selected primary schools in the East London Education District. Data were collected from grade 7 teachers and learners in selected township schools in East London, by means of semi-structured interviews, questionnaires and focus groups. Semi-structured questionnaires were administered to teachers and learners, individual interviews were conducted with NS head of department, focus group and interviews were held with grade 7 NS learners. Quantitative and qualitative data were independently analysed and merged at the interpretation stage for triangulation of results. The questions were grouped according to their themes. The researcher’s findings revealed that teachers linked the teaching of NS concepts by showing the teaching skills. Teachers used code-switching for learners to understand the scientific concepts for positive attitude to improve the learner performance. Teachers experienced problems using English as a Language of Learning and Teaching (LoLT) while teaching NS concepts, teachers’ understanding of NS influenced their ability to implement of transformational curriculum, but learners did not benefit much when learning science in English Language and those policies were designed by the Department of Education without teacher involvement. The study concluded by noting that It emerged that teachers and learners experienced difficulties in teaching and learning of the NS concepts.
- Full Text:
- Date Issued: 2019
- Authors: Kumanda, Nomaroma
- Date: 2019
- Subjects: Science -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15925 , vital:40564
- Description: The study sought to examine the teaching of Natural Sciences (NS) concepts to English second language speakers in selected primary schools. Grade 7 was chosen for the investigation as it precedes the last class at primary school. The researcher investigated the teaching and learning of Natural sciences concepts. A mixed method design was used. The research questions focused on the teaching of NS, learner-centred strategies used, challenges encountered, strategies employed by teachers when teaching NS, and the implications for science education.The purpose was to examine the teaching of Natural Sciences concepts to English second language speakers in selected primary schools in the East London Education District. Data were collected from grade 7 teachers and learners in selected township schools in East London, by means of semi-structured interviews, questionnaires and focus groups. Semi-structured questionnaires were administered to teachers and learners, individual interviews were conducted with NS head of department, focus group and interviews were held with grade 7 NS learners. Quantitative and qualitative data were independently analysed and merged at the interpretation stage for triangulation of results. The questions were grouped according to their themes. The researcher’s findings revealed that teachers linked the teaching of NS concepts by showing the teaching skills. Teachers used code-switching for learners to understand the scientific concepts for positive attitude to improve the learner performance. Teachers experienced problems using English as a Language of Learning and Teaching (LoLT) while teaching NS concepts, teachers’ understanding of NS influenced their ability to implement of transformational curriculum, but learners did not benefit much when learning science in English Language and those policies were designed by the Department of Education without teacher involvement. The study concluded by noting that It emerged that teachers and learners experienced difficulties in teaching and learning of the NS concepts.
- Full Text:
- Date Issued: 2019
Young adults' experiences of romantic love relationships in virtual space
- Authors: Lambert, Tania
- Date: 2017
- Subjects: Online dating , Intimacy (Psychology) , Young adults
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/7577 , vital:21930
- Description: The arena for finding an intimate partner has changed significantly in the 21st century with online love relationships becoming more prevalent. Research indicates that individuals do experience meaningful online romantic love relationships and that these relationships often lead to face to face (FTF) relationships. However, limited research has been done on exploring the experiences of those who are/were involved in online romantic love relationships. Furthermore, research conducted on online love romantic relationships generally fails to investigate how people experience passion online, hereby ignoring this integral component of romantic love. The primary aim of the research study was to explore young adults’ experiences of romantic love relationships in virtual space. More specifically, the study explored how young adults experienced intimacy and passion as elements of romantic love online. The study was viewed from an interpretative paradigm and made use of a qualitative approach. The researcher conducted in-depth, semi-structured interviews with seven participants which were transcribed, and analysed using Interpretative Phenomenological Analysis (IPA). Four superordinate themes were identified, namely, Online Intimacy, Online Romance and Passion, Online Love, and Social Exchange Online. The participants experienced romantic love online and reported that these relationships were very significant, real and impacted on their psychological well-being. The study created a heuristic base that will provide impetus for this emerging field in research.
- Full Text:
- Date Issued: 2017
- Authors: Lambert, Tania
- Date: 2017
- Subjects: Online dating , Intimacy (Psychology) , Young adults
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/7577 , vital:21930
- Description: The arena for finding an intimate partner has changed significantly in the 21st century with online love relationships becoming more prevalent. Research indicates that individuals do experience meaningful online romantic love relationships and that these relationships often lead to face to face (FTF) relationships. However, limited research has been done on exploring the experiences of those who are/were involved in online romantic love relationships. Furthermore, research conducted on online love romantic relationships generally fails to investigate how people experience passion online, hereby ignoring this integral component of romantic love. The primary aim of the research study was to explore young adults’ experiences of romantic love relationships in virtual space. More specifically, the study explored how young adults experienced intimacy and passion as elements of romantic love online. The study was viewed from an interpretative paradigm and made use of a qualitative approach. The researcher conducted in-depth, semi-structured interviews with seven participants which were transcribed, and analysed using Interpretative Phenomenological Analysis (IPA). Four superordinate themes were identified, namely, Online Intimacy, Online Romance and Passion, Online Love, and Social Exchange Online. The participants experienced romantic love online and reported that these relationships were very significant, real and impacted on their psychological well-being. The study created a heuristic base that will provide impetus for this emerging field in research.
- Full Text:
- Date Issued: 2017
Tourism management in selected municipalities in the Eden District: a theoretical study
- Authors: Lamont, Andrew John
- Date: 2014
- Subjects: Sustainable tourism -- South Africa , Tourism -- South Africa -- Management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/8025 , vital:24460
- Description: For attainment sustainable tourism requires the growth of tourism‟s contribution to the economy and society as well as the sustainable use of resources and the environment. The achievement of both relies on dependable and sound understanding, appropriate development and management of the tourism demand. As demand patterns and economic structures change, no industry, and in particular no industry at the national or regional level, could or should assume that there is a constant or increasing flow of demand for its outputs and thus focus solely on resource issues (Butler, 1996). According to Elliot (1997:19) local government plays an important role in tourism, as it is only governments that have the authority to provide political stability, security and the legal and financial framework which tourism requires. Connell et al (2009) argue that one of the more important roles of local government is the development and implementation of community planning, legislation and policy. However, while tourism-related developments are usually integrated with economic development or official community plans, often there is no guiding policy framework or identified area of responsibility for tourism, which can be problematic for effective and sustainable tourism development. The effectiveness of local tourism governance in achieving the goals of sustainable tourism depends on the effectiveness of institutional structures and processes, and the rational resources and skill sets available (Healy, 2006). This study examines the arrangements of selected municipalities and the effectiveness of their local tourism governance and its relevance to sustainable tourism.
- Full Text:
- Date Issued: 2014
- Authors: Lamont, Andrew John
- Date: 2014
- Subjects: Sustainable tourism -- South Africa , Tourism -- South Africa -- Management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/8025 , vital:24460
- Description: For attainment sustainable tourism requires the growth of tourism‟s contribution to the economy and society as well as the sustainable use of resources and the environment. The achievement of both relies on dependable and sound understanding, appropriate development and management of the tourism demand. As demand patterns and economic structures change, no industry, and in particular no industry at the national or regional level, could or should assume that there is a constant or increasing flow of demand for its outputs and thus focus solely on resource issues (Butler, 1996). According to Elliot (1997:19) local government plays an important role in tourism, as it is only governments that have the authority to provide political stability, security and the legal and financial framework which tourism requires. Connell et al (2009) argue that one of the more important roles of local government is the development and implementation of community planning, legislation and policy. However, while tourism-related developments are usually integrated with economic development or official community plans, often there is no guiding policy framework or identified area of responsibility for tourism, which can be problematic for effective and sustainable tourism development. The effectiveness of local tourism governance in achieving the goals of sustainable tourism depends on the effectiveness of institutional structures and processes, and the rational resources and skill sets available (Healy, 2006). This study examines the arrangements of selected municipalities and the effectiveness of their local tourism governance and its relevance to sustainable tourism.
- Full Text:
- Date Issued: 2014
Hostage incident management : preparedness and response of international non-governmental organisations
- Authors: Lauvik. Kjell Erik
- Date: 2014
- Subjects: Non-governmental organizations -- Security measures , Hostage negotiations , Conflict management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8347 , http://hdl.handle.net/10948/d1020800
- Description: It is broadly accepted that there is a need for better security management and protocols for hostage incident management, there is currently a lack of basic empirical knowledge about the existing security management protocols with reference to existing policies, knowledge and the capability of International Non-Governmental Organisations (INGOs) to handle hostage incidents. Many INGOs have successfully managed high-profile hostage crises, but there is still a considerable level of uncertainty about the way these crises have been solved and the way their success can be seen in relation to other crises. This study aimed to understand how INGOs prepare themselves for hostage incidents, whether policies, procedures are in place, how they manage hostage situations, and also how INGO staff are trained and prepared. The methodology adopted for this study was qualitative and comprised of indepth interviews with sixteen INGOs and ten industry experts and a review of INGO documents, policies and plans. The study sheds light on some of the less talked-about aspects for INGO security management in general, as well as preparedness and responsibility towards their staff. The study suggests that while most organisations have a level of preparedness in place, enhancing each agency’s respective policies may assist the organisation in better management. The study also found that there is a higher use of ransom payment than expected, and that there is an increasing willingness to engage external expertise to assisting in managing a hostage crisis. The study makes several recommendations that may have policy implications, including pre-deployment hostile environment training, reviewing potential cooperation between INGOs and United Nations, and the use of external resources to assist in managing a hostage crisis. It also recommends a revision of existing negotiation models, as the current models are lacking in addressing protracted hostage cases. The establishment of an accurate database of incidents to allow for improved interpretation of trends and scope of hostage cases is also recommended.
- Full Text:
- Date Issued: 2014
- Authors: Lauvik. Kjell Erik
- Date: 2014
- Subjects: Non-governmental organizations -- Security measures , Hostage negotiations , Conflict management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8347 , http://hdl.handle.net/10948/d1020800
- Description: It is broadly accepted that there is a need for better security management and protocols for hostage incident management, there is currently a lack of basic empirical knowledge about the existing security management protocols with reference to existing policies, knowledge and the capability of International Non-Governmental Organisations (INGOs) to handle hostage incidents. Many INGOs have successfully managed high-profile hostage crises, but there is still a considerable level of uncertainty about the way these crises have been solved and the way their success can be seen in relation to other crises. This study aimed to understand how INGOs prepare themselves for hostage incidents, whether policies, procedures are in place, how they manage hostage situations, and also how INGO staff are trained and prepared. The methodology adopted for this study was qualitative and comprised of indepth interviews with sixteen INGOs and ten industry experts and a review of INGO documents, policies and plans. The study sheds light on some of the less talked-about aspects for INGO security management in general, as well as preparedness and responsibility towards their staff. The study suggests that while most organisations have a level of preparedness in place, enhancing each agency’s respective policies may assist the organisation in better management. The study also found that there is a higher use of ransom payment than expected, and that there is an increasing willingness to engage external expertise to assisting in managing a hostage crisis. The study makes several recommendations that may have policy implications, including pre-deployment hostile environment training, reviewing potential cooperation between INGOs and United Nations, and the use of external resources to assist in managing a hostage crisis. It also recommends a revision of existing negotiation models, as the current models are lacking in addressing protracted hostage cases. The establishment of an accurate database of incidents to allow for improved interpretation of trends and scope of hostage cases is also recommended.
- Full Text:
- Date Issued: 2014
The role of apex predators in ecosystem function: fear triggered cascades regulated by differential prey vulnerability
- Authors: Le Roux, Elizabeth
- Date: 2016
- Subjects: Top predators -- Ecology Predation (Biology)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/14774 , vital:27849
- Description: Trophic cascades involving large terrestrial mammals are very seldom empirically demonstrated. The high species diversity often associated with terrestrial systems is thought to modulate the strength of trophic cascades. In speciose systems, species often vary in vulnerability to consumption, hence some species are less responsive to top-down pressure. African large mammalian herbivores are highly diverse and vary greatly in body size, a characteristic linked to vulnerability to predation. Moreover, Africa is one of the last places to still support megaherbivores, species that have grown large enough to be practically impervious to non-human predation. Thus an African ecosystem is the ideal setting to explore trophic cascades in speciose terrestrial systems. In this study I explored patterns in trophic interaction amongst carnivores, vulnerable mesoherbivore and predator-invulnerable megaherbivores in an intact African savanna at a variety of spatial scales. I examined the mechanistic links between trophic levels at the patch scale through fine scale empirical manipulation of predation risk. In addition, I assessed the landscape scale biological relevance of these trophic interactions through correlative observations over large spatiotemporal scales. I present the first evidence of community level trophic cascades explicitly involving megaherbivores. I demonstrate how megaherbivores’ disregard of predation risk masks the effects of predator-triggered trophic cascades and weakens their impact on the ecosystem. The risk of predation triggered a spatial response in vulnerable species, driving them into safe areas, yet did not influence the space use of megaherbivores. This species-specific spatial response had contrasting effects on nutrient distribution. Vulnerable herbivores’ fear-induced foraging behaviour led to localised nutrient accumulation whereas the foraging behaviour of predator-invulnerable megaherbivores led to nutrient redistribution across the landscape. In addition, the fear-driven spatial differences in mesoherbivore grazing impact and nutrient deposition led to landscape scale changes in the distribution and persistence of herbivore maintained grass communities, so-called grazing lawns. However, the grazing activity of the in-vulnerable megagrazer, white rhino (Ceratotherium simum) weakened the effect of this trophic cascade by creating and maintaining grazing lawns within the risky habitat avoided by mesograzers. This study contributes to our understanding of what drives the variation among patterns of trophic control and provides the first evidence of the modulating influence that megaherbivores have on predator-triggered trophic cascades.
- Full Text:
- Date Issued: 2016
- Authors: Le Roux, Elizabeth
- Date: 2016
- Subjects: Top predators -- Ecology Predation (Biology)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/14774 , vital:27849
- Description: Trophic cascades involving large terrestrial mammals are very seldom empirically demonstrated. The high species diversity often associated with terrestrial systems is thought to modulate the strength of trophic cascades. In speciose systems, species often vary in vulnerability to consumption, hence some species are less responsive to top-down pressure. African large mammalian herbivores are highly diverse and vary greatly in body size, a characteristic linked to vulnerability to predation. Moreover, Africa is one of the last places to still support megaherbivores, species that have grown large enough to be practically impervious to non-human predation. Thus an African ecosystem is the ideal setting to explore trophic cascades in speciose terrestrial systems. In this study I explored patterns in trophic interaction amongst carnivores, vulnerable mesoherbivore and predator-invulnerable megaherbivores in an intact African savanna at a variety of spatial scales. I examined the mechanistic links between trophic levels at the patch scale through fine scale empirical manipulation of predation risk. In addition, I assessed the landscape scale biological relevance of these trophic interactions through correlative observations over large spatiotemporal scales. I present the first evidence of community level trophic cascades explicitly involving megaherbivores. I demonstrate how megaherbivores’ disregard of predation risk masks the effects of predator-triggered trophic cascades and weakens their impact on the ecosystem. The risk of predation triggered a spatial response in vulnerable species, driving them into safe areas, yet did not influence the space use of megaherbivores. This species-specific spatial response had contrasting effects on nutrient distribution. Vulnerable herbivores’ fear-induced foraging behaviour led to localised nutrient accumulation whereas the foraging behaviour of predator-invulnerable megaherbivores led to nutrient redistribution across the landscape. In addition, the fear-driven spatial differences in mesoherbivore grazing impact and nutrient deposition led to landscape scale changes in the distribution and persistence of herbivore maintained grass communities, so-called grazing lawns. However, the grazing activity of the in-vulnerable megagrazer, white rhino (Ceratotherium simum) weakened the effect of this trophic cascade by creating and maintaining grazing lawns within the risky habitat avoided by mesograzers. This study contributes to our understanding of what drives the variation among patterns of trophic control and provides the first evidence of the modulating influence that megaherbivores have on predator-triggered trophic cascades.
- Full Text:
- Date Issued: 2016
A model for using learners' online behaviour to inform differentiated instructional design in MOODLE
- Authors: Leppan, Ronald George
- Date: 2019
- Subjects: Cyberspace -- Psychological aspects , Web applications in libraries Moodle Special education -- Computer programs Computer-assisted instruction -- Computer programs Open source software
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40393 , vital:36155
- Description: This thesis proposes a learning analytics-based process model, derived from a web analytics process, which aims to build a learner profile of attributes from Moodle log files that can be used for differentiated instructional design in Moodle. Commercial websites are rife with examples of personalisation based on web analytics, while the personalisation of online learning has not yet gained such widespread adoption. Several Instructional Design Models recommend that, in addition to taking prior knowledge and learning outcomes into account, instruction should also be informed by learner attributes. Learning design choices should be made based on unique learner attributes that influence their learning processes. Learner attributes are generally derived from well-known learning styles and associated learning style questionnaires. However, there are some criticisms of learning style theories and the use of questionnaires to create a learner profile. Attributes that can be inferred from learners’ online behaviour could provide a more dynamic learner profile. Education institutions are increasingly using Learning Management Systems, such as Moodle, to deliver and manage online learning. Moodle is not designed to create a learner profile or provide differentiated instruction. However, the abundant data generated by learners accessing course material presented in Moodle provides an opportunity for educators to build such a dynamic learner profile. Individual learner profiles can be used by educators who desire to tailor instruction to the needs of their learners. The proposed model was developed and evaluated using an iterative design focused approach that incorporates characteristics of a web analytics process, instructional design models, Learning Management Systems, educational data mining and adaptive education technologies. At each iteration, the model was evaluated using a technical risk and efficacy strategy. This strategy proposes a formative evaluation in an artificial setting. Evaluation criteria used include relevance, consistency, practicality and utility. The contributions of this thesis address the lack of prescriptive guidance on how to analyse learner online behaviours in order to differentiate learning design in Moodle. The theoretical contribution is a model for a dynamic data-driven approach to profile building and a phased differentiated learning design in a Learning Management System. The practical contribution is an evaluation of the expected practicality and utility of learner modelling from Moodle log files and the provision of tailored instruction using standard Moodle tools. The proposed model recommends that educators should define goals, develop Key Performance Indicators (KPI) to measure goal attainment, collect and analyse suitable metrics towards KPIs, test optional alternative hypotheses and implement actionable insights. To enable differentiated instruction, two phases are necessary: learner modelling and differentiated learning design. Both phases rely on the selection of suitable attributes which influence learning processes, and which can be dynamically inferred from online behaviours. In differentiated learning design, the selection/creation and sequencing of Learning Objects are influenced by the learner attributes. In learner modelling, the data sources and data analysis techniques should enable the discovery of the learner attributes that was catered for in the learning design. Educators who follow the steps described in the proposed model will be capable of building a learner profile from Moodle log files that can be used for differentiated instruction based on any learning style theory.
- Full Text:
- Date Issued: 2019
A model for using learners' online behaviour to inform differentiated instructional design in MOODLE
- Authors: Leppan, Ronald George
- Date: 2019
- Subjects: Cyberspace -- Psychological aspects , Web applications in libraries Moodle Special education -- Computer programs Computer-assisted instruction -- Computer programs Open source software
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40393 , vital:36155
- Description: This thesis proposes a learning analytics-based process model, derived from a web analytics process, which aims to build a learner profile of attributes from Moodle log files that can be used for differentiated instructional design in Moodle. Commercial websites are rife with examples of personalisation based on web analytics, while the personalisation of online learning has not yet gained such widespread adoption. Several Instructional Design Models recommend that, in addition to taking prior knowledge and learning outcomes into account, instruction should also be informed by learner attributes. Learning design choices should be made based on unique learner attributes that influence their learning processes. Learner attributes are generally derived from well-known learning styles and associated learning style questionnaires. However, there are some criticisms of learning style theories and the use of questionnaires to create a learner profile. Attributes that can be inferred from learners’ online behaviour could provide a more dynamic learner profile. Education institutions are increasingly using Learning Management Systems, such as Moodle, to deliver and manage online learning. Moodle is not designed to create a learner profile or provide differentiated instruction. However, the abundant data generated by learners accessing course material presented in Moodle provides an opportunity for educators to build such a dynamic learner profile. Individual learner profiles can be used by educators who desire to tailor instruction to the needs of their learners. The proposed model was developed and evaluated using an iterative design focused approach that incorporates characteristics of a web analytics process, instructional design models, Learning Management Systems, educational data mining and adaptive education technologies. At each iteration, the model was evaluated using a technical risk and efficacy strategy. This strategy proposes a formative evaluation in an artificial setting. Evaluation criteria used include relevance, consistency, practicality and utility. The contributions of this thesis address the lack of prescriptive guidance on how to analyse learner online behaviours in order to differentiate learning design in Moodle. The theoretical contribution is a model for a dynamic data-driven approach to profile building and a phased differentiated learning design in a Learning Management System. The practical contribution is an evaluation of the expected practicality and utility of learner modelling from Moodle log files and the provision of tailored instruction using standard Moodle tools. The proposed model recommends that educators should define goals, develop Key Performance Indicators (KPI) to measure goal attainment, collect and analyse suitable metrics towards KPIs, test optional alternative hypotheses and implement actionable insights. To enable differentiated instruction, two phases are necessary: learner modelling and differentiated learning design. Both phases rely on the selection of suitable attributes which influence learning processes, and which can be dynamically inferred from online behaviours. In differentiated learning design, the selection/creation and sequencing of Learning Objects are influenced by the learner attributes. In learner modelling, the data sources and data analysis techniques should enable the discovery of the learner attributes that was catered for in the learning design. Educators who follow the steps described in the proposed model will be capable of building a learner profile from Moodle log files that can be used for differentiated instruction based on any learning style theory.
- Full Text:
- Date Issued: 2019
A proposed theory of war economies and supporting policy framework for dismantling war economies in Sub-Saharan Africa
- Liebenberg, Frederick Sybert
- Authors: Liebenberg, Frederick Sybert
- Date: 2015
- Subjects: Africa, Sub-Saharan -- Economic policy , Military occupation -- Economic aspects -- Africa, Sub-Saharan , War-time economies
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/3235 , vital:20414
- Description: Utilising the Grounded Theory Research Method, this study identified a range of open, axial and selective codes, through a literature review, which resulted in the formulation of a proposed theory of how war economies are formed and maintained. Based on the theoretical proposition of the proposed theory, a policy framework for dismantling such war economies was also developed and presented. The proposed theory of war economies essentially argues that war economies are formed in post-colonial sub-Saharan Africa because of the existence of an artificial state. The existence of an artificial state is ascribed to the emerging legacies of colonial state formation processes, which created failed state entities which are unable to produce public goods for all its citizens because of its inability to maintain a monopoly of violence whilst maintain full administrative control over its territory. This inability results in an increase in the vulnerability of state and non-state actors. In response to these vulnerabilities, both state and non-state actors established a range of parallel political, economic and military structures. These structures in turn made use of both network and resource capacities to create an environment where politics are economised and conflict is commercialised, in order to mitigate the impacts of state failure and the inability to produce public goods. The result of the creation of an environment where politics are economised and conflict is commercialised, is the creation of incentives, structures and processes to ensure that conflict and associated conditions of instability are sustained in order to ensure primitive accumulation of wealth and resources. Based on the core theoretical proposition of the proposed theory, the study also presents a broad policy framework for dismantling war economies. In broad terms the framework proposes an integrated state-building process, based on a range of policy mechanisms aimed at maintaining a monopoly over violence, increasing administrative control, dismantling conflict networks and ensuring effective and efficient resource management.
- Full Text:
- Date Issued: 2015
- Authors: Liebenberg, Frederick Sybert
- Date: 2015
- Subjects: Africa, Sub-Saharan -- Economic policy , Military occupation -- Economic aspects -- Africa, Sub-Saharan , War-time economies
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/3235 , vital:20414
- Description: Utilising the Grounded Theory Research Method, this study identified a range of open, axial and selective codes, through a literature review, which resulted in the formulation of a proposed theory of how war economies are formed and maintained. Based on the theoretical proposition of the proposed theory, a policy framework for dismantling such war economies was also developed and presented. The proposed theory of war economies essentially argues that war economies are formed in post-colonial sub-Saharan Africa because of the existence of an artificial state. The existence of an artificial state is ascribed to the emerging legacies of colonial state formation processes, which created failed state entities which are unable to produce public goods for all its citizens because of its inability to maintain a monopoly of violence whilst maintain full administrative control over its territory. This inability results in an increase in the vulnerability of state and non-state actors. In response to these vulnerabilities, both state and non-state actors established a range of parallel political, economic and military structures. These structures in turn made use of both network and resource capacities to create an environment where politics are economised and conflict is commercialised, in order to mitigate the impacts of state failure and the inability to produce public goods. The result of the creation of an environment where politics are economised and conflict is commercialised, is the creation of incentives, structures and processes to ensure that conflict and associated conditions of instability are sustained in order to ensure primitive accumulation of wealth and resources. Based on the core theoretical proposition of the proposed theory, the study also presents a broad policy framework for dismantling war economies. In broad terms the framework proposes an integrated state-building process, based on a range of policy mechanisms aimed at maintaining a monopoly over violence, increasing administrative control, dismantling conflict networks and ensuring effective and efficient resource management.
- Full Text:
- Date Issued: 2015
Triggering physics lecturers' reflections on the instructional affordance of their use of representations: a design-based study
- Authors: Lombard, Elsa Helena
- Date: 2014
- Subjects: Physics -- Study and teaching , Physics -- Research
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/2899 , vital:20361
- Description: There is growing awareness in the physics education research community about the importance of using representations in physics teaching and the need for lecturers to reflect on their practice. This research study adopted a design-based research approach in an attempt to design a reliable, valid and practically useful artefact (framework/strategy) that could be used to trigger introductory physics lecturers’ reflections on their instructional use of representations. The artefact, which was instantiated with physics lecturers, comprised an observation protocol, an accompanying definitions key, a communication platform, and an instrument to assess the outcome (the levels of reflection). The video-data of lecturer practice were analysed using a priori codes to generate profiles of teaching practice. The resulting profiles were used to trigger individual video-stimulated reflection. The levels of reflection were assessed using a purpose-designed ‘Expectations of Reflection’ taxonomy. Thereafter a set of design guidelines and design principles were generated to guide further similar design-based educational studies. The process was validated via interview data but, while it was deemed a valid and reliable solution to the research problem, there were varying levels of perceived value of the artefact among the participating lecturers.
- Full Text:
- Date Issued: 2014
- Authors: Lombard, Elsa Helena
- Date: 2014
- Subjects: Physics -- Study and teaching , Physics -- Research
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/2899 , vital:20361
- Description: There is growing awareness in the physics education research community about the importance of using representations in physics teaching and the need for lecturers to reflect on their practice. This research study adopted a design-based research approach in an attempt to design a reliable, valid and practically useful artefact (framework/strategy) that could be used to trigger introductory physics lecturers’ reflections on their instructional use of representations. The artefact, which was instantiated with physics lecturers, comprised an observation protocol, an accompanying definitions key, a communication platform, and an instrument to assess the outcome (the levels of reflection). The video-data of lecturer practice were analysed using a priori codes to generate profiles of teaching practice. The resulting profiles were used to trigger individual video-stimulated reflection. The levels of reflection were assessed using a purpose-designed ‘Expectations of Reflection’ taxonomy. Thereafter a set of design guidelines and design principles were generated to guide further similar design-based educational studies. The process was validated via interview data but, while it was deemed a valid and reliable solution to the research problem, there were varying levels of perceived value of the artefact among the participating lecturers.
- Full Text:
- Date Issued: 2014
A strategy to enhance the role of the church as a social service delivery agent in fighting poverty in contemporary South Africa
- Lujabe, Busisiwe Tando Tabiso
- Authors: Lujabe, Busisiwe Tando Tabiso
- Date: 2018
- Subjects: Community-based social services Community development
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/17876 , vital:28477
- Description: The possible role and involvement of the Church in social development has reemerged as an important focus of contemporary academic and religious development discourse in South Africa. There are strong voices arguing for churches and other Faith-Based Organisations to be regarded as strategic in contributing to addressing the challenge of poverty as agents of social development. Yet, as church congregations multiply throughout South Africa, they appear to be less responsive to the challenge of poverty facing South African communities, contrary to the rich history of churches in the past. The need for churches to be involved in sustainable community-driven development initiatives to fight poverty in their local communities cannot be denied nor be met with just rhetoric and scholarly dissertations by theologians and academics. The vicious cycle of poverty in our communities must be eradicated as it represents a social injustice in terms of South Africa‘s Constitution and speaks to deep structural inequalities inherent in our society. Whilst researchers have made several proposals for churches to move from social welfare and relief, there appears to be little research with a clear practical strategy which congregations can implement to enhance their social service delivery role from social relief to sustainable community development. This has left a considerable gap which the current research sought to address. This study thus responds to the call by previous research for churches to implement strategies other than mere relief. Hence, this study contributes to the religious development discourse in South Africa, by developing a strategy to enhance Church-based social service delivery initiatives from social relief efforts which are not sustainable, to community development efforts which are sustainable and which will be consistent with the current social development policy context and contextually relevant to the socio-economic challenges of poverty and its consequences in South Africa. The study was conducted in two phases. During phase one, the main purpose was to gain a deeper understanding of the historical and current involvement of the Church in providing social services which address poverty in communities, to enhance understanding of the factors which influence the provision of social services by churches, as well as to understand participants views of how church-based social service delivery can be improved in order to fight poverty. For phase two, the goal was to develop a strategy to enhance church-based social service delivery from being social relief to being community development oriented. The following objectives guided the research process: To review selected and applicable literature to gain a deeper understanding of the historical and current involvement of the Church in the delivery of social services in order to fight poverty; To explore and describe the perceptions of church leaders and congregation members of the historical and current involvement of the Church in the delivery of social services in order to fight poverty; To explore and describe the factors which influence Church-based social service delivery in fighting poverty; To explore the views of church leaders and congregation members on how church-based social service delivery can be improved in their churches to inform the development of a strategy to enhance church-based social service delivery in fighting poverty. This study employed a qualitative research approach grounded in the interpretivist social science paradigm. The qualitative research approach necessitated an exploratory, descriptive and contextual method of inquiry. A descriptive case study method was also used, with the Methodist Church of Southern Africa selected as the main case of focus. The target population in this research comprised of Christian churches with a historical involvement in social service delivery in pre-apartheid South Africa. Purposeful sampling of 5 churches was undertaken, namely; Roman Catholic Church (RCC), Anglican Church (AC), Dutch Reformed Church (DRC), KwaSizabantu Mission (KSB) and Methodist Church of Southern Africa (MCSA). Data collection was conducted in two phases. Phase one comprised a literature review; Phase two comprised gathering empirical evidence by conducting face to face semi-structured interviews with clergy and from conducting one focus group interview with congregants. The information obtained from participants was transcribed, coded and analysed using content analysis and by a computer-assisted qualitative data analysis software (CAQDAS), namely ATLAS.ti. Findings revealed a marked difference between the historical and current churchbased social service delivery suggestive of decline, accompanied by the lack of empowerment opportunities for current church leaders and congregation members in community development facilitation. Further evidence suggest the lack of cooperation between church leaders and congregation members; as well as the lack of sustainability of interventions owing to an absence of resources and the lack of capacity to create sustainable economic opportunities. Findings also revealed that church congregations are rich with people with various assets - skills, strengths, capabilities, passions, gifts, talents in various fields, which they can share with one another as congregations and communities. The discussion of findings reflected that historically, Church-based social service provision involved holistic intervention mechanisms, empowerment, collaborations and sustainability of interventions suggestive of second generation strategies of community development, while currently, Church-based social service provision involves mostly social relief and social welfare efforts suggestive of first generation strategies. The findings suggest a holistic strategy for ―reawakening the co-operativeness‖ of congregations to facilitate sustainable Church-based social service delivery towards fighting poverty in local communities. The strategy which was then developed and described with its sub-strategies, namely: Establishment of collaborative relationships Creation of empowerment opportunities Facilitation of holistic interventions The goal of the strategy is to guide church leaders and congregation members in facilitating sustainable Church-based social service programmes to fight poverty.
- Full Text:
- Date Issued: 2018
- Authors: Lujabe, Busisiwe Tando Tabiso
- Date: 2018
- Subjects: Community-based social services Community development
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/17876 , vital:28477
- Description: The possible role and involvement of the Church in social development has reemerged as an important focus of contemporary academic and religious development discourse in South Africa. There are strong voices arguing for churches and other Faith-Based Organisations to be regarded as strategic in contributing to addressing the challenge of poverty as agents of social development. Yet, as church congregations multiply throughout South Africa, they appear to be less responsive to the challenge of poverty facing South African communities, contrary to the rich history of churches in the past. The need for churches to be involved in sustainable community-driven development initiatives to fight poverty in their local communities cannot be denied nor be met with just rhetoric and scholarly dissertations by theologians and academics. The vicious cycle of poverty in our communities must be eradicated as it represents a social injustice in terms of South Africa‘s Constitution and speaks to deep structural inequalities inherent in our society. Whilst researchers have made several proposals for churches to move from social welfare and relief, there appears to be little research with a clear practical strategy which congregations can implement to enhance their social service delivery role from social relief to sustainable community development. This has left a considerable gap which the current research sought to address. This study thus responds to the call by previous research for churches to implement strategies other than mere relief. Hence, this study contributes to the religious development discourse in South Africa, by developing a strategy to enhance Church-based social service delivery initiatives from social relief efforts which are not sustainable, to community development efforts which are sustainable and which will be consistent with the current social development policy context and contextually relevant to the socio-economic challenges of poverty and its consequences in South Africa. The study was conducted in two phases. During phase one, the main purpose was to gain a deeper understanding of the historical and current involvement of the Church in providing social services which address poverty in communities, to enhance understanding of the factors which influence the provision of social services by churches, as well as to understand participants views of how church-based social service delivery can be improved in order to fight poverty. For phase two, the goal was to develop a strategy to enhance church-based social service delivery from being social relief to being community development oriented. The following objectives guided the research process: To review selected and applicable literature to gain a deeper understanding of the historical and current involvement of the Church in the delivery of social services in order to fight poverty; To explore and describe the perceptions of church leaders and congregation members of the historical and current involvement of the Church in the delivery of social services in order to fight poverty; To explore and describe the factors which influence Church-based social service delivery in fighting poverty; To explore the views of church leaders and congregation members on how church-based social service delivery can be improved in their churches to inform the development of a strategy to enhance church-based social service delivery in fighting poverty. This study employed a qualitative research approach grounded in the interpretivist social science paradigm. The qualitative research approach necessitated an exploratory, descriptive and contextual method of inquiry. A descriptive case study method was also used, with the Methodist Church of Southern Africa selected as the main case of focus. The target population in this research comprised of Christian churches with a historical involvement in social service delivery in pre-apartheid South Africa. Purposeful sampling of 5 churches was undertaken, namely; Roman Catholic Church (RCC), Anglican Church (AC), Dutch Reformed Church (DRC), KwaSizabantu Mission (KSB) and Methodist Church of Southern Africa (MCSA). Data collection was conducted in two phases. Phase one comprised a literature review; Phase two comprised gathering empirical evidence by conducting face to face semi-structured interviews with clergy and from conducting one focus group interview with congregants. The information obtained from participants was transcribed, coded and analysed using content analysis and by a computer-assisted qualitative data analysis software (CAQDAS), namely ATLAS.ti. Findings revealed a marked difference between the historical and current churchbased social service delivery suggestive of decline, accompanied by the lack of empowerment opportunities for current church leaders and congregation members in community development facilitation. Further evidence suggest the lack of cooperation between church leaders and congregation members; as well as the lack of sustainability of interventions owing to an absence of resources and the lack of capacity to create sustainable economic opportunities. Findings also revealed that church congregations are rich with people with various assets - skills, strengths, capabilities, passions, gifts, talents in various fields, which they can share with one another as congregations and communities. The discussion of findings reflected that historically, Church-based social service provision involved holistic intervention mechanisms, empowerment, collaborations and sustainability of interventions suggestive of second generation strategies of community development, while currently, Church-based social service provision involves mostly social relief and social welfare efforts suggestive of first generation strategies. The findings suggest a holistic strategy for ―reawakening the co-operativeness‖ of congregations to facilitate sustainable Church-based social service delivery towards fighting poverty in local communities. The strategy which was then developed and described with its sub-strategies, namely: Establishment of collaborative relationships Creation of empowerment opportunities Facilitation of holistic interventions The goal of the strategy is to guide church leaders and congregation members in facilitating sustainable Church-based social service programmes to fight poverty.
- Full Text:
- Date Issued: 2018
Development of insulin resistance in a rat model and the effects of sutherlandia frutescens as treatment and prevention
- Authors: Mackenzie, Janine
- Date: 2010
- Subjects: Metabolic syndrome , Insulin resistance -- Animal models , Obesity -- Treatment
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10340 , http://hdl.handle.net/10948/d1016216
- Description: The global number of obese people has reached pandemic proportions. High caloric diets and reduced physical exercise are to blame for this growing epidemic. Obesity has a very complex association with several other metabolic disorders, such as insulin resistance (IR), diabetes mellitus type 2 (DMT2) and cardiovascular disease. This puts a huge burden on health care systems world wide and claims many lives. Sutherlandia frutescens is a traditionally used herb, which is known to have anti-diabetic properties. However, the direct mode of action of S. frutescens still remains to be elucidated. The aim of this study was to investigate the developmental stages of high fat diet (HFD)-induced IR, to illuminate the pathogenesis of IR with a focal point on modifications in the lipid metabolism. Furthermore, the effects of S. frutescens as a treatment or prevention drug for IR and associated metabolic changes were examined. Two sets of experiments were conducted on male Wistar rats. In the first experiment rats, one week post weaning received a low fat diet (LFD), high fat diet (HFD) or HFD supplemented with S. frutescens (50mg/kg BW/d). Rats were sacrificed at week 0, 1, 2, 4, 8 and 12 in the feeding regime. In a second experiment rats were fed with a LFD or a HFD for 12 weeks and treated thereafter with S. frutescens (50mg/kg BW/d), metformin (13mg/kg BW/d) or water (control) for 28 days. Rats in the second experiment were sacrificed at week 12 to confirm IR while concurrently run rats were sacrificed after 28 days of treatment. For all the experiments rats were anaesthetized, blood was removed and rats were dissected. Plasma samples were analyzed for insulin, glucose, blood lipid parameters and cytokines. Liver, muscle and adipose tissue were analyzed for glucose uptake, total lipid content, lipid profile and fatty acid profile. It was shown that the intake of HFD caused IR and hyperinsulinaemia. The developmental stages in experiment one confirmed that an increase in plasma free fatty acids preceeded the onset of IR. Plasma and tissue lipid parameters (free fatty acid-, triglyceride- and cholesterol concentrations) showed pathological modifications in the HFD group. An ectopic accumulation of fat was observed in muscle and liver, as well as a change in membrane fatty acid profile. The results for circulating cytokines were somewhat inconclusive. Rats supplemented with S. frutescens did not develop HFD-induced IR (study one) or IR was reversed (study two). S. frutescens treatment also resulted in positive changes in plasma and tissue lipid parameters. In summary, an animal model for HFD-induced IR was established and the detrimental effect of elevated plasma FFA on glucose and lipid metabolism was observed. A novel discovery suggests that the anti-diabetic mode of action of S. frutescens is through modulation of lipid metabolism. It was also established that S. frutescens has the potential to prevent IR in vivo.
- Full Text:
- Date Issued: 2010
- Authors: Mackenzie, Janine
- Date: 2010
- Subjects: Metabolic syndrome , Insulin resistance -- Animal models , Obesity -- Treatment
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10340 , http://hdl.handle.net/10948/d1016216
- Description: The global number of obese people has reached pandemic proportions. High caloric diets and reduced physical exercise are to blame for this growing epidemic. Obesity has a very complex association with several other metabolic disorders, such as insulin resistance (IR), diabetes mellitus type 2 (DMT2) and cardiovascular disease. This puts a huge burden on health care systems world wide and claims many lives. Sutherlandia frutescens is a traditionally used herb, which is known to have anti-diabetic properties. However, the direct mode of action of S. frutescens still remains to be elucidated. The aim of this study was to investigate the developmental stages of high fat diet (HFD)-induced IR, to illuminate the pathogenesis of IR with a focal point on modifications in the lipid metabolism. Furthermore, the effects of S. frutescens as a treatment or prevention drug for IR and associated metabolic changes were examined. Two sets of experiments were conducted on male Wistar rats. In the first experiment rats, one week post weaning received a low fat diet (LFD), high fat diet (HFD) or HFD supplemented with S. frutescens (50mg/kg BW/d). Rats were sacrificed at week 0, 1, 2, 4, 8 and 12 in the feeding regime. In a second experiment rats were fed with a LFD or a HFD for 12 weeks and treated thereafter with S. frutescens (50mg/kg BW/d), metformin (13mg/kg BW/d) or water (control) for 28 days. Rats in the second experiment were sacrificed at week 12 to confirm IR while concurrently run rats were sacrificed after 28 days of treatment. For all the experiments rats were anaesthetized, blood was removed and rats were dissected. Plasma samples were analyzed for insulin, glucose, blood lipid parameters and cytokines. Liver, muscle and adipose tissue were analyzed for glucose uptake, total lipid content, lipid profile and fatty acid profile. It was shown that the intake of HFD caused IR and hyperinsulinaemia. The developmental stages in experiment one confirmed that an increase in plasma free fatty acids preceeded the onset of IR. Plasma and tissue lipid parameters (free fatty acid-, triglyceride- and cholesterol concentrations) showed pathological modifications in the HFD group. An ectopic accumulation of fat was observed in muscle and liver, as well as a change in membrane fatty acid profile. The results for circulating cytokines were somewhat inconclusive. Rats supplemented with S. frutescens did not develop HFD-induced IR (study one) or IR was reversed (study two). S. frutescens treatment also resulted in positive changes in plasma and tissue lipid parameters. In summary, an animal model for HFD-induced IR was established and the detrimental effect of elevated plasma FFA on glucose and lipid metabolism was observed. A novel discovery suggests that the anti-diabetic mode of action of S. frutescens is through modulation of lipid metabolism. It was also established that S. frutescens has the potential to prevent IR in vivo.
- Full Text:
- Date Issued: 2010
Development of spunlaced nonwoven filters from PAN, PPS and PI fibres for industrial use
- Authors: Maduna, Lebo
- Date: 2019
- Subjects: Textile fibers -- Mechanical properties , Nonwoven fabrics --Technological innovations Textile fibers, Synthetic -- Mechanical properties
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32610 , vital:32266
- Description: The aim of this work was to produce filter fabrics suitable for high temperature and other conditions encountered in coal power plants using the spunlacing manufacturing technique. Polyacrylonitrile (PAN), polyphenylene sulfide (PPS) and polyimide (PI) fibres being combined suitable for this purpose, each at three aerial density of (440, 500 and 560 g/m2) and each at three water jet pressures of (60, 80 and 90 bars) were produced. The effect of changing these on the fabric air permeability, tensile strength and filtration properties were investigated and optimized. For this purpose, the Box-Behnken experimental design (BBD) was considered the best and therefore used. The PPS/PI fabrics were found to consistently have the highest air permeability, tensile strength and filtration performance, followed by the PPS fabrics and the PAN fabrics. As could be expected, an increase in area weight and water jet pressure generally resulted in a decrease in air permeability irrespective of the fabric types, this being due to the increased number of fibres and therefore greater fibre surface area and entanglement respectively. For fabric tensile strength, the effects of varying fabric area weight and water jet pressure were not so straight forward. For cross direction (CD) an increase in water jet pressure resulted in an increase tensile strength whereas in the machine direction (MD) there was a decrease when the water jet pressure was increased. The filtration efficiency and dust holding capacity of the fabrics were found to be around 96% and 211g/m2, respectively, with the exception of the PPS (500 g/m2 80 bar) fabrics. Increasing the amount of dust being fed to the fabric during each loading cycle, it caused an increase in pressure drop, as the fabrics became increasingly clogged forming a cake layer.
- Full Text:
- Date Issued: 2019
- Authors: Maduna, Lebo
- Date: 2019
- Subjects: Textile fibers -- Mechanical properties , Nonwoven fabrics --Technological innovations Textile fibers, Synthetic -- Mechanical properties
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32610 , vital:32266
- Description: The aim of this work was to produce filter fabrics suitable for high temperature and other conditions encountered in coal power plants using the spunlacing manufacturing technique. Polyacrylonitrile (PAN), polyphenylene sulfide (PPS) and polyimide (PI) fibres being combined suitable for this purpose, each at three aerial density of (440, 500 and 560 g/m2) and each at three water jet pressures of (60, 80 and 90 bars) were produced. The effect of changing these on the fabric air permeability, tensile strength and filtration properties were investigated and optimized. For this purpose, the Box-Behnken experimental design (BBD) was considered the best and therefore used. The PPS/PI fabrics were found to consistently have the highest air permeability, tensile strength and filtration performance, followed by the PPS fabrics and the PAN fabrics. As could be expected, an increase in area weight and water jet pressure generally resulted in a decrease in air permeability irrespective of the fabric types, this being due to the increased number of fibres and therefore greater fibre surface area and entanglement respectively. For fabric tensile strength, the effects of varying fabric area weight and water jet pressure were not so straight forward. For cross direction (CD) an increase in water jet pressure resulted in an increase tensile strength whereas in the machine direction (MD) there was a decrease when the water jet pressure was increased. The filtration efficiency and dust holding capacity of the fabrics were found to be around 96% and 211g/m2, respectively, with the exception of the PPS (500 g/m2 80 bar) fabrics. Increasing the amount of dust being fed to the fabric during each loading cycle, it caused an increase in pressure drop, as the fabrics became increasingly clogged forming a cake layer.
- Full Text:
- Date Issued: 2019
In search of identity: an anthropological study on the experiences of Rastafarians in contemporary Malawi
- Authors: Maganga, Stewart Martin
- Date: 2019
- Subjects: Malawi -- Religious life and customs , Rastafari movement Identity (Philosophical concept)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42536 , vital:36666
- Description: Prior to 1994, religious freedoms were largely restricted because the constitution at the time vested its powers in the president who was at the time was Dr. Hastings Kamuzu Banda. Banda, who ruled Malawi for thirty years, sought to present Malawi to the outside world as a Christian nation. This was purposefully done by ignoring the existence of other religious faiths in the country of which Rastafari was one. Although the Rastafari movement was in existence during Banda’s presidency, most Rastas found it difficult to practice their religious beliefs freely. Because of this, it was found that throughout the three decades Banda was in power, the Rastafari movement in Malawi was virtually underground. This further gave the public impression to the public at the time that Rastas were non-existent in the country. It was only after the general elections of 1994 that Malawians became aware of the existence of the Rastafari movement in the country. With that said, there remains a paucity of written information on the Rastafari movement in Malawi, that is before and after the 1994 general election. To be able to establish why the Rastafari movement continues to grow in Malawi, this thesis began by addressing the question of why a certain group of individuals would seek becoming to Rastas in Malawi including its impact on their lives including relationships with both friends and family members. For the many that embraced Rastafari, the intention was to embrace a spiritual identity that was separate to that of their parents. Most raised the concern that the religions that they were previously affiliated did not allow them the freedom to explore their spirituality. This further raises the question regarding the link between established religions and spirituality. In as much as Rastafari has provided the individuals in this study a sense of meaning and identity in their lives, they have had to contend with facing confrontation with friends and family members. This thesis also explored the experiences that come with being a Rasta in Malawi. Amongst the issues that are of concern to the Rasta community is that for the many Rasta children that attend public schools, most are denied their right to attend classes with dreadlocks. Most Rastas had hoped that with the advent of democracy in Malawi, their fundamental rights would be recognised and protected under the constitution. What this thesis has demonstrated that despite the existence of democracy in Malawi, it did ultimately result in a society that would be open to diversity. What this study has demonstrated is that Malawi continues to remain a highly conservative society. This is further illustrated in the way Malawian Rastas have had to contend with being denied employment opportunities including their fundamental right to smoke chamba (marijuana) freely. This thesis set out to argue that the democracy brought about by the elections of 1994 did not necessarily result in the improved conditions of minority religious groups like Rastafarians. This is despite the current constitution allowing for religious freedom. Despite this, the thesis further set out to show that the Rastafari movement does have vital role in the current dispensation. The issues that make the Rastafari movement pertinent in present-day Malawi include issues of corruption and neo-colonialism. This thesis concluded that more must be done to improve the conditions of Rastas in Malawi. Some of recommendations that were raised in this study included reviewing the current policy regarding the length of hair that one wears to school as it relates to one’s religious beliefs. The other recommendation that was raised in this study includes amending the Religious and Moral Education (RME) school curriculum in order that it becomes inclusive of other religious faiths that are existing in the country. In addition, the current legislation regarding the possession of chamba must be amended to accommodate for religious groups such as Rastas who use it for religious purposes.
- Full Text:
- Date Issued: 2019
- Authors: Maganga, Stewart Martin
- Date: 2019
- Subjects: Malawi -- Religious life and customs , Rastafari movement Identity (Philosophical concept)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42536 , vital:36666
- Description: Prior to 1994, religious freedoms were largely restricted because the constitution at the time vested its powers in the president who was at the time was Dr. Hastings Kamuzu Banda. Banda, who ruled Malawi for thirty years, sought to present Malawi to the outside world as a Christian nation. This was purposefully done by ignoring the existence of other religious faiths in the country of which Rastafari was one. Although the Rastafari movement was in existence during Banda’s presidency, most Rastas found it difficult to practice their religious beliefs freely. Because of this, it was found that throughout the three decades Banda was in power, the Rastafari movement in Malawi was virtually underground. This further gave the public impression to the public at the time that Rastas were non-existent in the country. It was only after the general elections of 1994 that Malawians became aware of the existence of the Rastafari movement in the country. With that said, there remains a paucity of written information on the Rastafari movement in Malawi, that is before and after the 1994 general election. To be able to establish why the Rastafari movement continues to grow in Malawi, this thesis began by addressing the question of why a certain group of individuals would seek becoming to Rastas in Malawi including its impact on their lives including relationships with both friends and family members. For the many that embraced Rastafari, the intention was to embrace a spiritual identity that was separate to that of their parents. Most raised the concern that the religions that they were previously affiliated did not allow them the freedom to explore their spirituality. This further raises the question regarding the link between established religions and spirituality. In as much as Rastafari has provided the individuals in this study a sense of meaning and identity in their lives, they have had to contend with facing confrontation with friends and family members. This thesis also explored the experiences that come with being a Rasta in Malawi. Amongst the issues that are of concern to the Rasta community is that for the many Rasta children that attend public schools, most are denied their right to attend classes with dreadlocks. Most Rastas had hoped that with the advent of democracy in Malawi, their fundamental rights would be recognised and protected under the constitution. What this thesis has demonstrated that despite the existence of democracy in Malawi, it did ultimately result in a society that would be open to diversity. What this study has demonstrated is that Malawi continues to remain a highly conservative society. This is further illustrated in the way Malawian Rastas have had to contend with being denied employment opportunities including their fundamental right to smoke chamba (marijuana) freely. This thesis set out to argue that the democracy brought about by the elections of 1994 did not necessarily result in the improved conditions of minority religious groups like Rastafarians. This is despite the current constitution allowing for religious freedom. Despite this, the thesis further set out to show that the Rastafari movement does have vital role in the current dispensation. The issues that make the Rastafari movement pertinent in present-day Malawi include issues of corruption and neo-colonialism. This thesis concluded that more must be done to improve the conditions of Rastas in Malawi. Some of recommendations that were raised in this study included reviewing the current policy regarding the length of hair that one wears to school as it relates to one’s religious beliefs. The other recommendation that was raised in this study includes amending the Religious and Moral Education (RME) school curriculum in order that it becomes inclusive of other religious faiths that are existing in the country. In addition, the current legislation regarding the possession of chamba must be amended to accommodate for religious groups such as Rastas who use it for religious purposes.
- Full Text:
- Date Issued: 2019
Characterization and ecology of selected micro-estuaries and micro-outlets in the Eastern Cape province, South Africa
- Authors: Magoro, Mandla Leon
- Date: 2018
- Subjects: Estuarine ecology -- South Africa -- Eastern Cape , Estuaries -- Management Estuaries -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31644 , vital:31640
- Description: South Africa has more than 200 Temporarily Open/Closed Estuaries (TOCEs) along its approximately 3000 km coastline. In addition, there are approximately 200 micro-estuaries and micro-outlets on the subcontinent, many of which share some of the characteristics with TOCEs but differ in that they are supplied by localised coastal stream catchments with a more limited supply of freshwater and less connectivity to the marine environment. Between 2015 and 2016, this study endeavoured to investigate the physico-chemical properties, microalgal dynamics as well as the seasonal species abundance and composition of aquatic invertebrates and fishes in four micro-estuaries and four micro-outlets along the warm-temperate section of the Eastern Cape coast. The micro-outlets were dominated by oligohaline or freshwater conditions, while the micro-estuaries were mostly mesohaline. Microalgal biomass in these systems was influenced by temperature, nutrient conditions and light availability. Chironomidae and Ephemeroptera dominated benthic macro-invertebrate communities in the micro-outlets, while Amphipoda and Mysida were most dominant in micro-estuaries. Copepoda and Amphipoda dominated the zooplankton assemblages in both system types. Nekton communities in micro-outlets were dominated by juvenile Myxus capensis and tadpoles (mostly Xenopus laevis), while Oreochromis mossambicus, Gilchristella aestuaria, M. capensis and Mugil cephalus were the four most common species in the micro-estuaries. Seasonal variations in physico-chemical parameters and community composition of both the nekton and invertebrates were recorded during this study. Micro-estuaries and micro-outlets exhibited relatively lower diversity and abundances of biota than TOCEs. Furthermore, the micro-estuaries have a low estuarine function when compared to TOCEs, while the micro-outlets have very limited estuarine characteristics and were dominated by freshwater biota. The micro-systems are smaller in size and contain lower proportions of estuary-associated taxa when compared to larger estuarine systems such as TOCEs and permanently open estuaries. The results of this study confirm that there are distinctions between the biota of iv the two micro-system types, thus making biotic assemblages, together with physico-chemical parameters, a viable tool for differentiating between micro-estuaries and micro-outlets. This study represents the first investigation into the ecological functioning of micro-estuaries and micro-outlets. As a whole, micro-systems serve as nursery areas for freshwater-associated invertebrate taxa. Due to their limited periods of stability, micro-estuaries serve as intermediate nursery areas for 0+ juveniles of estuary-associated marine fish which, after less than a year, then migrate to larger estuarine systems located nearby. The small catchment size and short period of stability in these systems heightens their level of sensitivity to water flow alterations through dams, direct water abstraction, afforestation and watercourse diversion, while their lower buffering capacity makes them more susceptible to pollution and nutrient inputs from intensive agricultural activities and urban expansion.
- Full Text:
- Date Issued: 2018
- Authors: Magoro, Mandla Leon
- Date: 2018
- Subjects: Estuarine ecology -- South Africa -- Eastern Cape , Estuaries -- Management Estuaries -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31644 , vital:31640
- Description: South Africa has more than 200 Temporarily Open/Closed Estuaries (TOCEs) along its approximately 3000 km coastline. In addition, there are approximately 200 micro-estuaries and micro-outlets on the subcontinent, many of which share some of the characteristics with TOCEs but differ in that they are supplied by localised coastal stream catchments with a more limited supply of freshwater and less connectivity to the marine environment. Between 2015 and 2016, this study endeavoured to investigate the physico-chemical properties, microalgal dynamics as well as the seasonal species abundance and composition of aquatic invertebrates and fishes in four micro-estuaries and four micro-outlets along the warm-temperate section of the Eastern Cape coast. The micro-outlets were dominated by oligohaline or freshwater conditions, while the micro-estuaries were mostly mesohaline. Microalgal biomass in these systems was influenced by temperature, nutrient conditions and light availability. Chironomidae and Ephemeroptera dominated benthic macro-invertebrate communities in the micro-outlets, while Amphipoda and Mysida were most dominant in micro-estuaries. Copepoda and Amphipoda dominated the zooplankton assemblages in both system types. Nekton communities in micro-outlets were dominated by juvenile Myxus capensis and tadpoles (mostly Xenopus laevis), while Oreochromis mossambicus, Gilchristella aestuaria, M. capensis and Mugil cephalus were the four most common species in the micro-estuaries. Seasonal variations in physico-chemical parameters and community composition of both the nekton and invertebrates were recorded during this study. Micro-estuaries and micro-outlets exhibited relatively lower diversity and abundances of biota than TOCEs. Furthermore, the micro-estuaries have a low estuarine function when compared to TOCEs, while the micro-outlets have very limited estuarine characteristics and were dominated by freshwater biota. The micro-systems are smaller in size and contain lower proportions of estuary-associated taxa when compared to larger estuarine systems such as TOCEs and permanently open estuaries. The results of this study confirm that there are distinctions between the biota of iv the two micro-system types, thus making biotic assemblages, together with physico-chemical parameters, a viable tool for differentiating between micro-estuaries and micro-outlets. This study represents the first investigation into the ecological functioning of micro-estuaries and micro-outlets. As a whole, micro-systems serve as nursery areas for freshwater-associated invertebrate taxa. Due to their limited periods of stability, micro-estuaries serve as intermediate nursery areas for 0+ juveniles of estuary-associated marine fish which, after less than a year, then migrate to larger estuarine systems located nearby. The small catchment size and short period of stability in these systems heightens their level of sensitivity to water flow alterations through dams, direct water abstraction, afforestation and watercourse diversion, while their lower buffering capacity makes them more susceptible to pollution and nutrient inputs from intensive agricultural activities and urban expansion.
- Full Text:
- Date Issued: 2018
A comparative analysis of anti-corruption legislation and anti-corruption agencies in the Eastern Cape and Northern Cape provices : a governance perspective
- Authors: Majila, Victoria Thozama
- Date: 2012
- Subjects: Political corruption -- South Africa , Misconduct in office -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8179 , http://hdl.handle.net/10948/2117 , Political corruption -- South Africa , Misconduct in office -- South Africa
- Description: This thesis analysed and compared the effectiveness of the anti-corruption legislation and anti-corruption agencies in the Eastern Cape and Northern Cape provinces. The thesis consists of six chapters. This study is based on the assumption that the struggle against corruption is best approached by developing a system of laws, institutions and supporting practices which promote integrity and make corrupt conduct a high-risk activity. It is imperative that a systemic approach is embarked upon in order to address the manner in which the major institutions and processes of the state are conquered and exploited by corrupt individuals and groups. With the magnitude in which hurdles exist that hamper the effectiveness of the country's anti-corruption legislation and anti-corruption agencies; South Africa is incapable of curbing corruption. With the purpose to determine a desired state of affairs, characteristics of effective anti-corruption agencies and anti-corruption legislation were presented. These served as a yardstick in measuring how effective such agencies and legislation are in South Africa. Reasons for failure of agencies and legislation are discussed. After discussing types of anti-corruption agencies, those that perform better than ix others were identified. Through literature review, the status quo concerning anti-corruption initiatives in South Africa was assessed. It was revealed that the level of the success of South African anti-corruption agencies and legislation has been limited. In the case of anti-corruption agencies, weaknesses such as fragmentation; insufficient coordination; poor delineation of responsibility; and assimilation of corruption work into a broader mandate were identified as major causes. Measures that are needed, such as informed citizens; a need to foster and sustain high levels of professional and ethically imbued civil servants; and legislation that supports the transition towards a corruption-free society that are needed to complement implementation of anti-corruption legislation, were also recognised. Ways of addressing such shortcomings that the writers identified are also presented. The methodology and design followed in the study are described. This is followed by the analysis and interpretation of the survey. The research findings are then presented. Based on the findings a number of recommendations that would assist in improving the effectiveness of anticorruption agencies and anti-corruption legislation are made. Flowing from the discussion of effective anti-corruption models that were identified by literature a model that would be ideal for South Africa is recommended.
- Full Text:
- Date Issued: 2012
- Authors: Majila, Victoria Thozama
- Date: 2012
- Subjects: Political corruption -- South Africa , Misconduct in office -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8179 , http://hdl.handle.net/10948/2117 , Political corruption -- South Africa , Misconduct in office -- South Africa
- Description: This thesis analysed and compared the effectiveness of the anti-corruption legislation and anti-corruption agencies in the Eastern Cape and Northern Cape provinces. The thesis consists of six chapters. This study is based on the assumption that the struggle against corruption is best approached by developing a system of laws, institutions and supporting practices which promote integrity and make corrupt conduct a high-risk activity. It is imperative that a systemic approach is embarked upon in order to address the manner in which the major institutions and processes of the state are conquered and exploited by corrupt individuals and groups. With the magnitude in which hurdles exist that hamper the effectiveness of the country's anti-corruption legislation and anti-corruption agencies; South Africa is incapable of curbing corruption. With the purpose to determine a desired state of affairs, characteristics of effective anti-corruption agencies and anti-corruption legislation were presented. These served as a yardstick in measuring how effective such agencies and legislation are in South Africa. Reasons for failure of agencies and legislation are discussed. After discussing types of anti-corruption agencies, those that perform better than ix others were identified. Through literature review, the status quo concerning anti-corruption initiatives in South Africa was assessed. It was revealed that the level of the success of South African anti-corruption agencies and legislation has been limited. In the case of anti-corruption agencies, weaknesses such as fragmentation; insufficient coordination; poor delineation of responsibility; and assimilation of corruption work into a broader mandate were identified as major causes. Measures that are needed, such as informed citizens; a need to foster and sustain high levels of professional and ethically imbued civil servants; and legislation that supports the transition towards a corruption-free society that are needed to complement implementation of anti-corruption legislation, were also recognised. Ways of addressing such shortcomings that the writers identified are also presented. The methodology and design followed in the study are described. This is followed by the analysis and interpretation of the survey. The research findings are then presented. Based on the findings a number of recommendations that would assist in improving the effectiveness of anticorruption agencies and anti-corruption legislation are made. Flowing from the discussion of effective anti-corruption models that were identified by literature a model that would be ideal for South Africa is recommended.
- Full Text:
- Date Issued: 2012
Understanding factors that influence the acceptance of electronic medical records by nurses in hospitals: a framework
- Authors: Makalima, Melissa
- Date: 2018
- Subjects: Electronic records -- Management , Information storage and retrieval systems -- Management Medical records -- South Africa Medical records -- Data processing
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31488 , vital:31495
- Description: Globally, unlike in the past, it is rare for a patient to consult the same healthcare provider throughout his or her lifetime. However, this makes it difficult to maintain informational continuity of care. Researchers have confirmed that paper-based methods of record keeping do not meet the needs of informational continuity of care. As a result, the popularity of electronic means of recordkeeping, specifically, electronic medical records (EMRs), is growing. However, the implementation of EMRs in hospitals is not without challenges with these challenges playing a significant role in the failure of EMRs. One such challenge is a lack of user acceptance. Research reveals that nurses comprise the largest user group of EMRs in the hospital setting. However, there is inadequate literature that focuses on the factors contributing to EMR acceptance with nurses as the user group. Hence, the main problem addressed in this research study relates to the inadequate understanding of the factors that influence the acceptance of EMRs by nurses. In order to address this problem, a literature review and a case study were conducted to ascertain and investigate the factors that influence the acceptance of EMRs by nurses. A total of 39 factors were formulated. Subsequent to the formulation of these factors, knowledge on the impact of each factor on EMR acceptance was collected. Socio-technical Systems Theory (STS) was used as a theoretical lens through which to view the resulting factors. The STS dimension from which each factor originates as well as the STS dimension influenced by the factor were identified. The analysis of the different stages of acceptance as well as the STS analysis resulted in a framework that could play an important role in providing a better understanding of EMR acceptance by nurses in hospitals. It was anticipated that this study would contribute to a better understanding of the factors that hospitals should address in order to create a conducive environment for EMR acceptance by nurses within the hospitals.
- Full Text:
- Date Issued: 2018
- Authors: Makalima, Melissa
- Date: 2018
- Subjects: Electronic records -- Management , Information storage and retrieval systems -- Management Medical records -- South Africa Medical records -- Data processing
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31488 , vital:31495
- Description: Globally, unlike in the past, it is rare for a patient to consult the same healthcare provider throughout his or her lifetime. However, this makes it difficult to maintain informational continuity of care. Researchers have confirmed that paper-based methods of record keeping do not meet the needs of informational continuity of care. As a result, the popularity of electronic means of recordkeeping, specifically, electronic medical records (EMRs), is growing. However, the implementation of EMRs in hospitals is not without challenges with these challenges playing a significant role in the failure of EMRs. One such challenge is a lack of user acceptance. Research reveals that nurses comprise the largest user group of EMRs in the hospital setting. However, there is inadequate literature that focuses on the factors contributing to EMR acceptance with nurses as the user group. Hence, the main problem addressed in this research study relates to the inadequate understanding of the factors that influence the acceptance of EMRs by nurses. In order to address this problem, a literature review and a case study were conducted to ascertain and investigate the factors that influence the acceptance of EMRs by nurses. A total of 39 factors were formulated. Subsequent to the formulation of these factors, knowledge on the impact of each factor on EMR acceptance was collected. Socio-technical Systems Theory (STS) was used as a theoretical lens through which to view the resulting factors. The STS dimension from which each factor originates as well as the STS dimension influenced by the factor were identified. The analysis of the different stages of acceptance as well as the STS analysis resulted in a framework that could play an important role in providing a better understanding of EMR acceptance by nurses in hospitals. It was anticipated that this study would contribute to a better understanding of the factors that hospitals should address in order to create a conducive environment for EMR acceptance by nurses within the hospitals.
- Full Text:
- Date Issued: 2018
Effects of 99-year leases on newly resettled farmers’ farm improvement, productivity and empowerment in Zimbabwe, 2007 to 2013
- Authors: Makaye, Peter
- Date: 2019
- Subjects: Land reform - -Zimbabwe , Land tenure -- Zimbabwe Farmers -- Zimbabwe Sustainable development -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40812 , vital:36239
- Description: This study seeks to interrogate the effects of 99-year leases on newly resettled farmers, with focus on Zimbabwe’s Fast Track Land Reform programme, shifting from its causes and processes to its variegated outcomes., The focus was on how the leasehold system has impinged on three variables: farm improvement, productivity, and empowerment. Quantitative data was collected from 92 newly resettled farmers randomly selected from three different farming regions in Zimbabwe: Region 2, an agriculturally well-endowed area concentrating on crop production, Region 4, an arid and hot region concentrating on livestock, and Region 5, specialising in sugar cane production under irrigation. To corroborate the survey findings, follow-up interviews and focus group discussions (FGDs) were carried out in these regions. Interviews with purposively sampled experts in agriculture in Zimbabwe were also conducted. Data are presented in charts and graphs as well as detailed descriptions. The study found that the 99-year leases influenced the fortunes of the farmers in different ways. In some areas, depending on the crop grown, the 99-year leases were accepted as a basis for a loan. In other instances, the leases have not been accepted as collateral and this has constrained the farmers’ ability to optimally utilise their farms optimally. Despite a general sense of insecurity, the farmers have shown a willingness to re-invest in the farms., Many improvements such as new accommodation for employees, the erection of fire guards, and the development of water sources are being made on the farms, all pointing to a desire for sustained utilisation of the A2 farms. The researcher proposes that serious effort has to be made towards making the 99-year leases acceptable as collateral for loans because otherwise, in the context of general undercapitalisation among the farmers, their ability to make the medium-scale farms optimally contribute to national accumulation will remain constrained. The form of tenure is related to the empowerment of the farmers, both materially and socially. This is in turn related to the sustainable use of the land and hence to sustainable development in Zimbabwe.
- Full Text:
- Date Issued: 2019
- Authors: Makaye, Peter
- Date: 2019
- Subjects: Land reform - -Zimbabwe , Land tenure -- Zimbabwe Farmers -- Zimbabwe Sustainable development -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40812 , vital:36239
- Description: This study seeks to interrogate the effects of 99-year leases on newly resettled farmers, with focus on Zimbabwe’s Fast Track Land Reform programme, shifting from its causes and processes to its variegated outcomes., The focus was on how the leasehold system has impinged on three variables: farm improvement, productivity, and empowerment. Quantitative data was collected from 92 newly resettled farmers randomly selected from three different farming regions in Zimbabwe: Region 2, an agriculturally well-endowed area concentrating on crop production, Region 4, an arid and hot region concentrating on livestock, and Region 5, specialising in sugar cane production under irrigation. To corroborate the survey findings, follow-up interviews and focus group discussions (FGDs) were carried out in these regions. Interviews with purposively sampled experts in agriculture in Zimbabwe were also conducted. Data are presented in charts and graphs as well as detailed descriptions. The study found that the 99-year leases influenced the fortunes of the farmers in different ways. In some areas, depending on the crop grown, the 99-year leases were accepted as a basis for a loan. In other instances, the leases have not been accepted as collateral and this has constrained the farmers’ ability to optimally utilise their farms optimally. Despite a general sense of insecurity, the farmers have shown a willingness to re-invest in the farms., Many improvements such as new accommodation for employees, the erection of fire guards, and the development of water sources are being made on the farms, all pointing to a desire for sustained utilisation of the A2 farms. The researcher proposes that serious effort has to be made towards making the 99-year leases acceptable as collateral for loans because otherwise, in the context of general undercapitalisation among the farmers, their ability to make the medium-scale farms optimally contribute to national accumulation will remain constrained. The form of tenure is related to the empowerment of the farmers, both materially and socially. This is in turn related to the sustainable use of the land and hence to sustainable development in Zimbabwe.
- Full Text:
- Date Issued: 2019
Immobilization of catalyst in a wall-coated micro-structured reactor for gas/liquid oxidation of p-cymene
- Authors: Makgwane, Peter Ramashadi
- Date: 2009
- Subjects: Oxidation , Cymene
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10389 , http://hdl.handle.net/10948/1182 , Oxidation , Cymene
- Description: The selective, liquid phase oxidation of p-cymene is an important synthetic route for the production of p-cresol via the tertiary cymene hydroperoxide (TCHP). The industrial-scale oxidation process is characterised by slow oxidation rates due to limitations in the mass transfer of oxidant (gaseous oxygen) into the liquid phase. However, like all other autoxidation reactions, the oxidation reaction is exothermic, following the typical free radical autoxidation reaction mechanism, which implies that careful temperature control is critical in order to prevent the further reaction of the initially formed hydroperoxide species. In the presence of metal catalysts, the limiting oxidation rate is the transfer of oxygen from the gas to liquid boundary interface. As a result, low product yields and poor productivity space-time yield are typically experienced. At high substrate conversions, by-products resulting from the decomposition of the formed hydroperoxides predominate. For this reason, the conversion of substrate is restricted to preserve the TCHP selectivity. The slow rates in industrial-scale p-cymene oxidations results in long oxidation times, typically 8-12 h. Substrate conversions are typically between 15-20 percent, and the TCHP selectivity ranges between 65-70 percent. The work described in this thesis concerns the oxidation of p-cymene in a microstructured falling film reactor (FFMSR). These reactor systems facilitate chemical reactors to have high mass and heat transfer rates because of high surface area-to-volume ratios. Due to their small internal volumes, these reactors are inherently safe to operate. These properties were exploited to improve the p-cymene oxidation rate and, consequently, the space-time yield. In order to evaluate the suitability of vanadium phosphate oxide (VPO) catalysts for use as supported catalyst in the FFMSR, different catalysts prepared from VOHPO4∙0.5H2O and VO(H2PO4)2 precursors was first evaluated for the oxidation of p-cymene in a well-stirred batch reactor. The results of the two activated catalysts, (VO)2P2O7 and VO(PO3)2 when used as powders in their pure form, showed a significant improvement in p-cymene oxidation rates with conversions up to 40 percent in 3-4 h reaction time with a TCHP selectivity of 75-80 percent. The (VO)2P2O7 catalyst showed better oxidation rates and selectivity when compared to the VO(PO3)2 catalyst obtained from the VO(H2PO4)2 precursor. The (VO)2P2O7 catalyst was supported on a stainless steel plate and the coated plate used to study the long-term stability and catalytic perfornance of the catalyst during p-cymene oxidations in a batch reactor. Comparable oxidation rates and TCHP selectivity were obtained with the stainless steel coated VPO catalyst when compared to the “free powder” (VO)2P2O7 catalyst. The results also showed that the stainless steel coated catalyst displays a slow, yet significant deactivation over extended reaction periods (250 h onstream). Characterization of the exposed (VO)2P2O7 catalyst to p-cymene oxidation conditions by powder XRD, SEM and TGA-MS showed that (VO)2P2O7 phase undergoes structural transformation back to VOHPO4∙0.5H2O phase over time. The (VO)2P2O7/-Al2O3 catalyst was used to coat the micro-channel reaction plates of the FFMSR. Both uncoated and coated micro-channel reaction plates were evaluated in the FFMSR for the oxidation of p-cymene. The FFMSR showed effective improvement of oxidation rates in terms of productivity space-time-yield at comparable batch p-cymene conversions. A Typical 10 percent conversion in catalysed batch oxidations at 1-2 h reaction time was achieved in few seconds (19 s) reaction time in FFMSR. The comparison of uncoated (i.e. uncatalysed) and coated (i.e. catalysed) FFMSR oxidations showed slight differences in oxidation rates. No clear explanation could be established with the present results for the observed same behaviour. However, the insufficient contact time between the gas and liquid reactants with the wall-coated solid catalyst is one of the possible causes for the observed behaviour of the coated and uncoated micro-channel plates. A simple developed kinetic model was used to confirm the obtained batch oxidation results using cumene as probe compound due to its similarity to p-cumene oxidation and extensive studied kinetics. With the estimated K values and available rate constants from literature, it was possible to predict the conversions in a batch reactor at the same typical micro-structured reactor residence time (i.e. of 19 s). The predicted conversions in the batch reactor were less than 0.1 percent even at harsh conditions such as 170 oC when compared to about 10 percent achieved in the micro-structured reactor at the same reaction temperature, reactants concentration and reaction time of 19 s. This difference in the reactor systems performance indicates the unique advantages offered by micro-structured reactors (e.g. improved mass transfer, temperature management and high surface-to-volume ratios) to perform typical gas/liquid mass transfer limited reactions such as cumene and p-cymene autoxidations.
- Full Text:
- Date Issued: 2009
- Authors: Makgwane, Peter Ramashadi
- Date: 2009
- Subjects: Oxidation , Cymene
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10389 , http://hdl.handle.net/10948/1182 , Oxidation , Cymene
- Description: The selective, liquid phase oxidation of p-cymene is an important synthetic route for the production of p-cresol via the tertiary cymene hydroperoxide (TCHP). The industrial-scale oxidation process is characterised by slow oxidation rates due to limitations in the mass transfer of oxidant (gaseous oxygen) into the liquid phase. However, like all other autoxidation reactions, the oxidation reaction is exothermic, following the typical free radical autoxidation reaction mechanism, which implies that careful temperature control is critical in order to prevent the further reaction of the initially formed hydroperoxide species. In the presence of metal catalysts, the limiting oxidation rate is the transfer of oxygen from the gas to liquid boundary interface. As a result, low product yields and poor productivity space-time yield are typically experienced. At high substrate conversions, by-products resulting from the decomposition of the formed hydroperoxides predominate. For this reason, the conversion of substrate is restricted to preserve the TCHP selectivity. The slow rates in industrial-scale p-cymene oxidations results in long oxidation times, typically 8-12 h. Substrate conversions are typically between 15-20 percent, and the TCHP selectivity ranges between 65-70 percent. The work described in this thesis concerns the oxidation of p-cymene in a microstructured falling film reactor (FFMSR). These reactor systems facilitate chemical reactors to have high mass and heat transfer rates because of high surface area-to-volume ratios. Due to their small internal volumes, these reactors are inherently safe to operate. These properties were exploited to improve the p-cymene oxidation rate and, consequently, the space-time yield. In order to evaluate the suitability of vanadium phosphate oxide (VPO) catalysts for use as supported catalyst in the FFMSR, different catalysts prepared from VOHPO4∙0.5H2O and VO(H2PO4)2 precursors was first evaluated for the oxidation of p-cymene in a well-stirred batch reactor. The results of the two activated catalysts, (VO)2P2O7 and VO(PO3)2 when used as powders in their pure form, showed a significant improvement in p-cymene oxidation rates with conversions up to 40 percent in 3-4 h reaction time with a TCHP selectivity of 75-80 percent. The (VO)2P2O7 catalyst showed better oxidation rates and selectivity when compared to the VO(PO3)2 catalyst obtained from the VO(H2PO4)2 precursor. The (VO)2P2O7 catalyst was supported on a stainless steel plate and the coated plate used to study the long-term stability and catalytic perfornance of the catalyst during p-cymene oxidations in a batch reactor. Comparable oxidation rates and TCHP selectivity were obtained with the stainless steel coated VPO catalyst when compared to the “free powder” (VO)2P2O7 catalyst. The results also showed that the stainless steel coated catalyst displays a slow, yet significant deactivation over extended reaction periods (250 h onstream). Characterization of the exposed (VO)2P2O7 catalyst to p-cymene oxidation conditions by powder XRD, SEM and TGA-MS showed that (VO)2P2O7 phase undergoes structural transformation back to VOHPO4∙0.5H2O phase over time. The (VO)2P2O7/-Al2O3 catalyst was used to coat the micro-channel reaction plates of the FFMSR. Both uncoated and coated micro-channel reaction plates were evaluated in the FFMSR for the oxidation of p-cymene. The FFMSR showed effective improvement of oxidation rates in terms of productivity space-time-yield at comparable batch p-cymene conversions. A Typical 10 percent conversion in catalysed batch oxidations at 1-2 h reaction time was achieved in few seconds (19 s) reaction time in FFMSR. The comparison of uncoated (i.e. uncatalysed) and coated (i.e. catalysed) FFMSR oxidations showed slight differences in oxidation rates. No clear explanation could be established with the present results for the observed same behaviour. However, the insufficient contact time between the gas and liquid reactants with the wall-coated solid catalyst is one of the possible causes for the observed behaviour of the coated and uncoated micro-channel plates. A simple developed kinetic model was used to confirm the obtained batch oxidation results using cumene as probe compound due to its similarity to p-cumene oxidation and extensive studied kinetics. With the estimated K values and available rate constants from literature, it was possible to predict the conversions in a batch reactor at the same typical micro-structured reactor residence time (i.e. of 19 s). The predicted conversions in the batch reactor were less than 0.1 percent even at harsh conditions such as 170 oC when compared to about 10 percent achieved in the micro-structured reactor at the same reaction temperature, reactants concentration and reaction time of 19 s. This difference in the reactor systems performance indicates the unique advantages offered by micro-structured reactors (e.g. improved mass transfer, temperature management and high surface-to-volume ratios) to perform typical gas/liquid mass transfer limited reactions such as cumene and p-cymene autoxidations.
- Full Text:
- Date Issued: 2009
South African public sector property management: a performance model
- Mali-Swelindawo, Bongiwe Lorreta, Yan, Bingwen
- Authors: Mali-Swelindawo, Bongiwe Lorreta , Yan, Bingwen
- Date: 2017
- Subjects: Performance -- Management -- South Africa Performance standards -- South Africa , Public buildings -- South Africa Real estate management -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/21185 , vital:29454
- Description: This research was conducted with the intention of accomplishing effective property management (PM) in order for public sector properties in South Africa (SA) SA to fulfil more remarkably, public sector property stakeholders’ requirements. In particular, this study was concluded within a South African municipal environment with the specific purpose of alleviating South African municipalities from problems associated with overall poor operational performance, dissatisfied public sector property stakeholders, and inadequacies in competitiveness and global alignment. The primary objective of this study was to develop a performance model deemed necessary for the effective management of public sector properties in SA. This was achieved by developing a performance model for effective management of public sector properties, a model to systematically monitor, measure and control current expectations and changes within a public sector property management function. Herewith, performance model for effective management of public sector properties in South Africa. At the time of conducting this study, there was no conceptual model developed for performance management of public sector properties. In order to develop the performance model, the conceptual model identified key elements that included: 1) obsolescence and strategic factors; 2) global alignment; 3) finance and cost control; 4) PESTEL impact; 5) transformation and sustainability; 6) leadership and governance; and 7) monitoring, measurement and control as influences that directly impact a perceived successful management of public sector properties in SA. The study also took the form of a quantitative research project that included a formal survey of the identified population sample. The main statistical procedure employed was Structural Equation Modelling (SEM). Originally, the study offered 24 hypotheses; however, only 11 hypotheses could be confirmed by SEM measurement. Therefore, through SEM, the significance of the relationships between variables could be tested. Appropriate quantitative data were collected from public and private South African Built Environment professionals, students and other academics. The research made use of snowball sampling through questionnaires, with a sample size of 171. It is anticipated that findings of this study will be acknowledged by public sector PM in an effort to resolve PM problems through the incorporation of pertinent recommendations. Likewise, since the performance model for effective management of public sector properties was not extant prior to this study, this research is cutting-edge and therefore pioneering to PM, especially within the public sector.
- Full Text:
- Date Issued: 2017
- Authors: Mali-Swelindawo, Bongiwe Lorreta , Yan, Bingwen
- Date: 2017
- Subjects: Performance -- Management -- South Africa Performance standards -- South Africa , Public buildings -- South Africa Real estate management -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/21185 , vital:29454
- Description: This research was conducted with the intention of accomplishing effective property management (PM) in order for public sector properties in South Africa (SA) SA to fulfil more remarkably, public sector property stakeholders’ requirements. In particular, this study was concluded within a South African municipal environment with the specific purpose of alleviating South African municipalities from problems associated with overall poor operational performance, dissatisfied public sector property stakeholders, and inadequacies in competitiveness and global alignment. The primary objective of this study was to develop a performance model deemed necessary for the effective management of public sector properties in SA. This was achieved by developing a performance model for effective management of public sector properties, a model to systematically monitor, measure and control current expectations and changes within a public sector property management function. Herewith, performance model for effective management of public sector properties in South Africa. At the time of conducting this study, there was no conceptual model developed for performance management of public sector properties. In order to develop the performance model, the conceptual model identified key elements that included: 1) obsolescence and strategic factors; 2) global alignment; 3) finance and cost control; 4) PESTEL impact; 5) transformation and sustainability; 6) leadership and governance; and 7) monitoring, measurement and control as influences that directly impact a perceived successful management of public sector properties in SA. The study also took the form of a quantitative research project that included a formal survey of the identified population sample. The main statistical procedure employed was Structural Equation Modelling (SEM). Originally, the study offered 24 hypotheses; however, only 11 hypotheses could be confirmed by SEM measurement. Therefore, through SEM, the significance of the relationships between variables could be tested. Appropriate quantitative data were collected from public and private South African Built Environment professionals, students and other academics. The research made use of snowball sampling through questionnaires, with a sample size of 171. It is anticipated that findings of this study will be acknowledged by public sector PM in an effort to resolve PM problems through the incorporation of pertinent recommendations. Likewise, since the performance model for effective management of public sector properties was not extant prior to this study, this research is cutting-edge and therefore pioneering to PM, especially within the public sector.
- Full Text:
- Date Issued: 2017
The impact of external shocks on economic performance and policy responses in Zimbabwe
- Authors: Manda, Smart
- Date: 2017
- Subjects: Macroeconomics , Economic forecasting -- Zimbabwe Economic development -- Zimbabwe Zimbabwe -- Economic conditions -- 21st century Developing countries -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/18354 , vital:28626
- Description: This study analysed the impact of external shocks on macroeconomic performance and policy responses in Zimbabwe for the period spanning from 2009 to 2016. The study was motivated by the rising global economic vulnerabilities following the global economic and financial crisis experienced between 2007 and 2009. The study was also in response to the concern by the Zimbabwean government that external shocks had become increasingly important in influencing macroeconomic developments in Zimbabwe. In view of the intensifying debate on external shocks, the study, therefore, sought to understand the impact of external shocks on economic performance and policy responses in Zimbabwe. The study contributes to empirical literature by assessing the relative contribution of external shocks in explaining business cycles, the main transmission mechanisms of the macroeconomic shocks in Zimbabwe, the extent to which shocks in Zimbabwe were synchronised with shocks affecting other regional countries and how effective were government policies in mitigating the impact of shocks in Zimbabwe. Zimbabwe is a fascinating case study given its unique exchange rate arrangements under the multiple currency system. The application of the micro-founded DSGE models in addition to the Structural Vector Autoregressive (SVAR) models is also a novel approach. The results of the DSGE model demonstrated that foreign output shocks and imported inflation were not important in accounting for developments in endogenous variables in Zimbabwe. In addition, the domestic output and inflation did not respond to a domestic monetary policy shock. However, the international commodity price was found to have some bearing on domestic output. Foreign interest rates had a positive effect on domestic interest rates. On the other hand, domestic variables did not respond to domestic interest rate movements. This effectively implies that whilst foreign interest rates influenced domestic interest rates, domestic interest rates did not influence real economic activity. In other words, the transmission mechanism was not from domestic monetary policy to real economic variables. The results of the SVAR model also confirmed the results obtained from the DSGE model. The results from the analysis of the synchronicity of shocks also provided very important information on the dynamics of external shocks and economic performance in Zimbabwe. These results pointed to the fact that although countries in the region experienced similar shocks, economic fluctuations were not synchronised implying that the shocks could be emanating from the domestic sources rather than external sources. The results from the analysis of the role of external shocks in explaining macroeconomic fluctuations in Zimbabwe revealed that domestic factors contribute more to macroeconomic fluctuations in Zimbabwe compared to external variables. The contribution of climatic factors to domestic output fluctuations was, however, found to have a limited or minimal impact on the economy. Regarding the monetary policy effectiveness, the study observed that there was a weak link between interest rates and output and inflation developments in Zimbabwe. The results also suggested a week link between interest rates and money supply in the economy. The results, however, suggested that international oil prices were very important in the domestic price formations, accounting for about 20 percent of the variation. The monetary policy conditional index on the other hand indicated that monetary conditions in the economy did not influence inflation and output developments, implying ineffectiveness of monetary policy. The results from the study demonstrated the fact that although external shocks do affect economic activity in Zimbabwe, domestic factors are more significant in influencing macroeconomic activity. The policy implication of the findings is that there is need to consider the domestic factors, which are more significant compared to the external factors. However, since monetary policy is not effective under the multiple currencies system, fiscal policy is important to deal with external shocks. This will also enable the economy to absorb the impact of external shocks into the economy. The policies should focus more on reducing the over-reliance on primary commodities for exports through diversification of the economy.
- Full Text:
- Date Issued: 2017
- Authors: Manda, Smart
- Date: 2017
- Subjects: Macroeconomics , Economic forecasting -- Zimbabwe Economic development -- Zimbabwe Zimbabwe -- Economic conditions -- 21st century Developing countries -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/18354 , vital:28626
- Description: This study analysed the impact of external shocks on macroeconomic performance and policy responses in Zimbabwe for the period spanning from 2009 to 2016. The study was motivated by the rising global economic vulnerabilities following the global economic and financial crisis experienced between 2007 and 2009. The study was also in response to the concern by the Zimbabwean government that external shocks had become increasingly important in influencing macroeconomic developments in Zimbabwe. In view of the intensifying debate on external shocks, the study, therefore, sought to understand the impact of external shocks on economic performance and policy responses in Zimbabwe. The study contributes to empirical literature by assessing the relative contribution of external shocks in explaining business cycles, the main transmission mechanisms of the macroeconomic shocks in Zimbabwe, the extent to which shocks in Zimbabwe were synchronised with shocks affecting other regional countries and how effective were government policies in mitigating the impact of shocks in Zimbabwe. Zimbabwe is a fascinating case study given its unique exchange rate arrangements under the multiple currency system. The application of the micro-founded DSGE models in addition to the Structural Vector Autoregressive (SVAR) models is also a novel approach. The results of the DSGE model demonstrated that foreign output shocks and imported inflation were not important in accounting for developments in endogenous variables in Zimbabwe. In addition, the domestic output and inflation did not respond to a domestic monetary policy shock. However, the international commodity price was found to have some bearing on domestic output. Foreign interest rates had a positive effect on domestic interest rates. On the other hand, domestic variables did not respond to domestic interest rate movements. This effectively implies that whilst foreign interest rates influenced domestic interest rates, domestic interest rates did not influence real economic activity. In other words, the transmission mechanism was not from domestic monetary policy to real economic variables. The results of the SVAR model also confirmed the results obtained from the DSGE model. The results from the analysis of the synchronicity of shocks also provided very important information on the dynamics of external shocks and economic performance in Zimbabwe. These results pointed to the fact that although countries in the region experienced similar shocks, economic fluctuations were not synchronised implying that the shocks could be emanating from the domestic sources rather than external sources. The results from the analysis of the role of external shocks in explaining macroeconomic fluctuations in Zimbabwe revealed that domestic factors contribute more to macroeconomic fluctuations in Zimbabwe compared to external variables. The contribution of climatic factors to domestic output fluctuations was, however, found to have a limited or minimal impact on the economy. Regarding the monetary policy effectiveness, the study observed that there was a weak link between interest rates and output and inflation developments in Zimbabwe. The results also suggested a week link between interest rates and money supply in the economy. The results, however, suggested that international oil prices were very important in the domestic price formations, accounting for about 20 percent of the variation. The monetary policy conditional index on the other hand indicated that monetary conditions in the economy did not influence inflation and output developments, implying ineffectiveness of monetary policy. The results from the study demonstrated the fact that although external shocks do affect economic activity in Zimbabwe, domestic factors are more significant in influencing macroeconomic activity. The policy implication of the findings is that there is need to consider the domestic factors, which are more significant compared to the external factors. However, since monetary policy is not effective under the multiple currencies system, fiscal policy is important to deal with external shocks. This will also enable the economy to absorb the impact of external shocks into the economy. The policies should focus more on reducing the over-reliance on primary commodities for exports through diversification of the economy.
- Full Text:
- Date Issued: 2017
Development of conservation strategies for Alepidea Amatymbica ECKL. & ZEYH. : a rare medicinal plant in the Eastern Cape, South Africa
- Mangoale, Ramatsobane Maureen
- Authors: Mangoale, Ramatsobane Maureen
- Date: 2017
- Subjects: Medicinal plants Plants, Cultivated
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/8667 , vital:33400
- Description: Conservation through cultivation has been recommended as a means to relieve overexploitation of medicinal plants. However, the medicinal plants users believe that plants collected from the wild are more potent than cultivated ones. Hence, there is a need for scientific documentation of the potency of cultivated medicinal plants to contribute to the development of a sustainable management strategy to conserve wild populations. This study was aimed at documenting cultivation techniques of a known medicinal plant, Alepidea amatymbica and to validate its medicinal efficacy. In order to identify overexploited medicinal plants in the study area and thus develop their conservation strategy, a survey on the trade of medicinal plants was conducted in selected towns of Amathole District Municipality of the Eastern Cape, South Africa. The survey revealed 67 plants belonging to 46 different families. Twenty-five medicinal plants were identified as overexploited and scarce and they were prioritized for conservation. Furthermore, 69.14 percent of the respondents were not willing to use cultivated medicinal plants. Lack of belief on the potency of cultivated plants and cultivation techniques were mentioned as the most significant constraints to conservation of medicinal plants. Also, the time for cultivated plants to reach maturity deterred herbal medicine practitioners from cultivating them. Alepidea amatymbica was mentioned as one of the most overexploited medicinal plants which has become scarce in the study area. This medicinal plant was therefore selected for this study. In order to develop sustainable conservation program for the species, various studies which include survey on the medicinal plants trade, cultivation, comparative micromorphology, elemental composition, toxicity, phytochemical and antioxidant activity of the wild and cultivated A. amatymbica were conducted. Cultivation of Alepidea amatymbica was conducted to determine the appropriate planting depth and rhizome fragment length for the growth of this plant. The experiment was laid out in a Complete Randomized Block Design (CRBD) with two factors in 6×3 factorial design. There were six levels of fragment length (1, 2, 3, 4, 5 and 6 cm) and three levels of burial depth (2.5, 5 and 7.5 cm). Emergence rate, number of leaves, leaf area, and plant height, number of florets, rhizome length gain, rhizome weight gain, shoot moisture and rhizome moisture were measured as growth parameters. The best overall yield in terms of plant height, shoot emergence, rhizome weight gain, number of florets and number of leaves was observed in 7.5 cm planting depth at 6 cm rhizome length. Four centimetre rhizome length had the highest leaf area of 111.9±3.5 cm2, 101.3±3.5 cm2, 105±3.5 cm2 at 2.5, 5, 7.5 cm planting depth respectively. Shorter fragment lengths showed high potential for vegetative propagation in terms of rhizome length gain at all burial depths. Scanning electron microscopy (SEM) was used to examine the foliar micro morphological characteristics while energy dispersive x-ray spectroscopy (EDXS) was used to determine the elemental composition in different parts of the wild and cultivated plants. The study revealed numerous differences between the wild and cultivated ones. These include deposition of epicuticular waxes, stomatal apparatus, helical thickening of the xylem walls, thickening of the epidermal cell layer and presence of starch grains in the parenchyma cells of the cortex. The EDXS analysis also revealed disproportionate quantities of C, O, Ca, K, Al, Mg, Si, Br and N as the major constituents in both cultivated and wild A. amatymbica specimens. The quantities of elements varied in the different parts of wild and cultivated plants. Toxicity of the methanol, water and acetone extracts of the fresh rhizome of the wild and cultivated A. amatymbica were evaluated using hatchability of cysts and lethality on the hatched cysts (nauplii) of Artemia salina. The highest hatching success was observed in the water extracts of the wild plant (46.16percent) with a MIC of 0.184 mg/ml while the cultivated plants had a hatching success of 40.83percent with MIC of 0.208 mg/ml. Highest mortality was observed in the acetone extract of the wild plants at the lethal dose of 0.191 mg/ml while the cultivated plant had a lethal dose of 0.270 mg/ml. Water extracts of both wild and cultivated plants showed similar lethal dose (LD50) of >1 mg/ml. Methanol extracts of both the wild and cultivated species exhibited almost the same level of toxicity (0.695 mg/ml and 0.628 mg/ml, respectively). Based on the Bastos criterion of toxicity indices of the lethality test, all the plant fractions demonstrated cytotoxicity effect, although the degree of their toxicity varied among the plants used. Standard spectrophotometry assays were used to quantify the phytochemical contents and to determine the antioxidant potentials of the cultivated and wild A. amatymbica. The results revealed different levels of phytochemicals with corresponding antioxidant activities. The wild extracts had higher phytochemical contents in most of the assays than cultivated extracts. Total phenol in the wild extracts ranged from 32.30±3.43 to 117.8±8.45 mg GAE/g with the acetone extracts having the highest content while the water extracts was the least. The range in the total phenol of the cultivated species was 66.46±5.29 to 98.44±6.08 mg GAE/g with the methanol extracts having the highest content while water extracts was the least. The flavonoids content ranged from 55.01±6.51 to 99.09±7.20 mg QE/mg and from 48.65±7.74 to 67.32±4.1 mg QE/mg for the wild and cultivated plants, respectively. The alkaloids contents ranged from 14.70±0.04 to 17.80±0.015 percent in the wild species while it ranged from 11.98±0.14 to 13.21±0.06 percent in the cultivated species. The wild species also showed higher antioxidant activities in most of the assays evaluated. The study revealed successful cultivation of the wild species of Alepidea amatymbica using fragments from the rhizome. The micromorphological study of both the wild and cultivated species showed minimal differences in the helical thickening of the walls in the xylem vessels and starch grain accumulation pattern. Although herbal medicine practitioners believe that cultivated species are not potent, however this study revealed some levels of phytochemicals contents and antioxidant activities which are comparable to the wild species. Cultivation is a major strategy in conserving nature and their resources. Hence, the successful domestication of A. amatymbica would help in reducing the pressure on the wild species while also meeting their medicinal demands purposes, utilisation and conserving for future generations.
- Full Text:
- Date Issued: 2017
- Authors: Mangoale, Ramatsobane Maureen
- Date: 2017
- Subjects: Medicinal plants Plants, Cultivated
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/8667 , vital:33400
- Description: Conservation through cultivation has been recommended as a means to relieve overexploitation of medicinal plants. However, the medicinal plants users believe that plants collected from the wild are more potent than cultivated ones. Hence, there is a need for scientific documentation of the potency of cultivated medicinal plants to contribute to the development of a sustainable management strategy to conserve wild populations. This study was aimed at documenting cultivation techniques of a known medicinal plant, Alepidea amatymbica and to validate its medicinal efficacy. In order to identify overexploited medicinal plants in the study area and thus develop their conservation strategy, a survey on the trade of medicinal plants was conducted in selected towns of Amathole District Municipality of the Eastern Cape, South Africa. The survey revealed 67 plants belonging to 46 different families. Twenty-five medicinal plants were identified as overexploited and scarce and they were prioritized for conservation. Furthermore, 69.14 percent of the respondents were not willing to use cultivated medicinal plants. Lack of belief on the potency of cultivated plants and cultivation techniques were mentioned as the most significant constraints to conservation of medicinal plants. Also, the time for cultivated plants to reach maturity deterred herbal medicine practitioners from cultivating them. Alepidea amatymbica was mentioned as one of the most overexploited medicinal plants which has become scarce in the study area. This medicinal plant was therefore selected for this study. In order to develop sustainable conservation program for the species, various studies which include survey on the medicinal plants trade, cultivation, comparative micromorphology, elemental composition, toxicity, phytochemical and antioxidant activity of the wild and cultivated A. amatymbica were conducted. Cultivation of Alepidea amatymbica was conducted to determine the appropriate planting depth and rhizome fragment length for the growth of this plant. The experiment was laid out in a Complete Randomized Block Design (CRBD) with two factors in 6×3 factorial design. There were six levels of fragment length (1, 2, 3, 4, 5 and 6 cm) and three levels of burial depth (2.5, 5 and 7.5 cm). Emergence rate, number of leaves, leaf area, and plant height, number of florets, rhizome length gain, rhizome weight gain, shoot moisture and rhizome moisture were measured as growth parameters. The best overall yield in terms of plant height, shoot emergence, rhizome weight gain, number of florets and number of leaves was observed in 7.5 cm planting depth at 6 cm rhizome length. Four centimetre rhizome length had the highest leaf area of 111.9±3.5 cm2, 101.3±3.5 cm2, 105±3.5 cm2 at 2.5, 5, 7.5 cm planting depth respectively. Shorter fragment lengths showed high potential for vegetative propagation in terms of rhizome length gain at all burial depths. Scanning electron microscopy (SEM) was used to examine the foliar micro morphological characteristics while energy dispersive x-ray spectroscopy (EDXS) was used to determine the elemental composition in different parts of the wild and cultivated plants. The study revealed numerous differences between the wild and cultivated ones. These include deposition of epicuticular waxes, stomatal apparatus, helical thickening of the xylem walls, thickening of the epidermal cell layer and presence of starch grains in the parenchyma cells of the cortex. The EDXS analysis also revealed disproportionate quantities of C, O, Ca, K, Al, Mg, Si, Br and N as the major constituents in both cultivated and wild A. amatymbica specimens. The quantities of elements varied in the different parts of wild and cultivated plants. Toxicity of the methanol, water and acetone extracts of the fresh rhizome of the wild and cultivated A. amatymbica were evaluated using hatchability of cysts and lethality on the hatched cysts (nauplii) of Artemia salina. The highest hatching success was observed in the water extracts of the wild plant (46.16percent) with a MIC of 0.184 mg/ml while the cultivated plants had a hatching success of 40.83percent with MIC of 0.208 mg/ml. Highest mortality was observed in the acetone extract of the wild plants at the lethal dose of 0.191 mg/ml while the cultivated plant had a lethal dose of 0.270 mg/ml. Water extracts of both wild and cultivated plants showed similar lethal dose (LD50) of >1 mg/ml. Methanol extracts of both the wild and cultivated species exhibited almost the same level of toxicity (0.695 mg/ml and 0.628 mg/ml, respectively). Based on the Bastos criterion of toxicity indices of the lethality test, all the plant fractions demonstrated cytotoxicity effect, although the degree of their toxicity varied among the plants used. Standard spectrophotometry assays were used to quantify the phytochemical contents and to determine the antioxidant potentials of the cultivated and wild A. amatymbica. The results revealed different levels of phytochemicals with corresponding antioxidant activities. The wild extracts had higher phytochemical contents in most of the assays than cultivated extracts. Total phenol in the wild extracts ranged from 32.30±3.43 to 117.8±8.45 mg GAE/g with the acetone extracts having the highest content while the water extracts was the least. The range in the total phenol of the cultivated species was 66.46±5.29 to 98.44±6.08 mg GAE/g with the methanol extracts having the highest content while water extracts was the least. The flavonoids content ranged from 55.01±6.51 to 99.09±7.20 mg QE/mg and from 48.65±7.74 to 67.32±4.1 mg QE/mg for the wild and cultivated plants, respectively. The alkaloids contents ranged from 14.70±0.04 to 17.80±0.015 percent in the wild species while it ranged from 11.98±0.14 to 13.21±0.06 percent in the cultivated species. The wild species also showed higher antioxidant activities in most of the assays evaluated. The study revealed successful cultivation of the wild species of Alepidea amatymbica using fragments from the rhizome. The micromorphological study of both the wild and cultivated species showed minimal differences in the helical thickening of the walls in the xylem vessels and starch grain accumulation pattern. Although herbal medicine practitioners believe that cultivated species are not potent, however this study revealed some levels of phytochemicals contents and antioxidant activities which are comparable to the wild species. Cultivation is a major strategy in conserving nature and their resources. Hence, the successful domestication of A. amatymbica would help in reducing the pressure on the wild species while also meeting their medicinal demands purposes, utilisation and conserving for future generations.
- Full Text:
- Date Issued: 2017