Bioinformatics tool development with a focus on structural bioinformatics and the analysis of genetic variation in humans
- Authors: Brown, David K
- Date: 2018
- Subjects: Bioinformatics , Human genetics -- Variation , High performance computing , Workflow management systems , Molecular dynamics , Next generation sequencing , Human Mutation Analysis (HUMA)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60708 , vital:27820
- Description: This thesis is divided into three parts, united under the general theme of bioinformatics tool development and variation analysis. Part 1 describes the design and development of the Job Management System (JMS), a workflow management system for high performance computing (HPC). HPC has become an integral part of bioinformatics. Computational methods for molecular dynamics and next generation sequencing (NGS) analysis, which require complex calculations on large datasets, are not yet feasible on desktop computers. As such, powerful computer clusters have been employed to perform these calculations. However, making use of these HPC clusters requires familiarity with command line interfaces. This excludes a large number of researchers from taking advantage of these resources. JMS was developed as a tool to make it easier for researchers without a computer science background to make use of HPC. Additionally, JMS can be used to host computational tools and pipelines and generates both web-based interfaces and RESTful APIs for those tools. The web-based interfaces can be used to quickly and easily submit jobs to the underlying cluster. The RESTful web API, on the other hand, allows JMS to provided backend functionality for external tools and web servers that want to run jobs on the cluster. Numerous tools and workflows have already been added to JMS, several of which have been incorporated into external web servers. One such web server is the Human Mutation Analysis (HUMA) web server and database. HUMA, the topic of part 2 of this thesis, is a platform for the analysis of genetic variation in humans. HUMA aggregates data from various existing databases into a single, connected and related database. The advantages of this are realized in the powerful querying abilities that it provides. HUMA includes protein, gene, disease, and variation data and can be searched from the angle of any one of these categories. For example, searching for a protein will return the protein data (e.g. protein sequences, structures, domains and families, and other meta-data). However, the related nature of the database means that genes, diseases, variation, and literature related to the protein will also be returned, giving users a powerful and holistic view of all data associated with the protein. HUMA also provides links to the original sources of the data, allowing users to follow the links to find additional details. HUMA aims to be a platform for the analysis of genetic variation. As such, it also provides tools to visualize and analyse the data (several of which run on the underlying cluster, via JMS). These tools include alignment and 3D structure visualization, homology modeling, variant analysis, and the ability to upload custom variation datasets and map them to proteins, genes and diseases. HUMA also provides collaboration features, allowing users to share and discuss datasets and job results. Finally, part 3 of this thesis focused on the development of a suite of tools, MD-TASK, to analyse genetic variation at the protein structure level via network analysis of molecular dynamics simulations. The use of MD-TASK in combination with the tools developed in the previous parts of this thesis is showcased via the analysis of variation in the renin-angiotensinogen complex, a vital part of the renin-angiotensin system.
- Full Text:
- Date Issued: 2018
- Authors: Brown, David K
- Date: 2018
- Subjects: Bioinformatics , Human genetics -- Variation , High performance computing , Workflow management systems , Molecular dynamics , Next generation sequencing , Human Mutation Analysis (HUMA)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60708 , vital:27820
- Description: This thesis is divided into three parts, united under the general theme of bioinformatics tool development and variation analysis. Part 1 describes the design and development of the Job Management System (JMS), a workflow management system for high performance computing (HPC). HPC has become an integral part of bioinformatics. Computational methods for molecular dynamics and next generation sequencing (NGS) analysis, which require complex calculations on large datasets, are not yet feasible on desktop computers. As such, powerful computer clusters have been employed to perform these calculations. However, making use of these HPC clusters requires familiarity with command line interfaces. This excludes a large number of researchers from taking advantage of these resources. JMS was developed as a tool to make it easier for researchers without a computer science background to make use of HPC. Additionally, JMS can be used to host computational tools and pipelines and generates both web-based interfaces and RESTful APIs for those tools. The web-based interfaces can be used to quickly and easily submit jobs to the underlying cluster. The RESTful web API, on the other hand, allows JMS to provided backend functionality for external tools and web servers that want to run jobs on the cluster. Numerous tools and workflows have already been added to JMS, several of which have been incorporated into external web servers. One such web server is the Human Mutation Analysis (HUMA) web server and database. HUMA, the topic of part 2 of this thesis, is a platform for the analysis of genetic variation in humans. HUMA aggregates data from various existing databases into a single, connected and related database. The advantages of this are realized in the powerful querying abilities that it provides. HUMA includes protein, gene, disease, and variation data and can be searched from the angle of any one of these categories. For example, searching for a protein will return the protein data (e.g. protein sequences, structures, domains and families, and other meta-data). However, the related nature of the database means that genes, diseases, variation, and literature related to the protein will also be returned, giving users a powerful and holistic view of all data associated with the protein. HUMA also provides links to the original sources of the data, allowing users to follow the links to find additional details. HUMA aims to be a platform for the analysis of genetic variation. As such, it also provides tools to visualize and analyse the data (several of which run on the underlying cluster, via JMS). These tools include alignment and 3D structure visualization, homology modeling, variant analysis, and the ability to upload custom variation datasets and map them to proteins, genes and diseases. HUMA also provides collaboration features, allowing users to share and discuss datasets and job results. Finally, part 3 of this thesis focused on the development of a suite of tools, MD-TASK, to analyse genetic variation at the protein structure level via network analysis of molecular dynamics simulations. The use of MD-TASK in combination with the tools developed in the previous parts of this thesis is showcased via the analysis of variation in the renin-angiotensinogen complex, a vital part of the renin-angiotensin system.
- Full Text:
- Date Issued: 2018
Biological activities of tulbaghia violacea against cryptococcus species
- Authors: Mitradev, Pattoo
- Date: 2018
- Subjects: Violaceae -- Therapeutic use -- South Africa , Anticoagulants (Medicine) , Medicinal plants -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32772 , vital:32357
- Description: Cryptococcus neoformans and Cryptococcus gattii, which are environmental yeasts, are the etiological agents of cryptococcosis in both immunocompromised and immunocompetent individuals, and account for high mortality and morbidity rates in sub-Saharan Africa. The current antifungal agents used for treatment of cryptococcal infections either target the fungal cell wall (β-(1,3) glucan and chitin) or cell membrane directly or ergosterol biosynthetic pathways or fungal DNA and RNA. Gaps in antifungal therapy include the unavailability and exhorbitant costs of these drugs especially to patients in the developing world. Drug resistance to conventional drugs is also an ever-increasing problem. It is therefore essential to find alternative natural compounds from medicinal plants that are safer, cheaper and more widely available. Tulbaghia violacea, also known as wild garlic, has been used as a traditional remedy in South Africa for the treatment of several ailments. Aqueous and organic extracts of the plant have been demonstrated to have antimicrobial and antifungal activity against several pathogens. However, there is a huge gap in our current knowledge in that the mechanism/s of action/s of these extracts have not been fully investigated. The focus of the current study therefore was to determine whether T. violacea extracts from the roots, rhizome, leaves and tubers exhibited antifungal activity against C. neoformans and C. gattii and to evaluate the ability of the rhizome extract to induce changes in key fungal virulence factors. Three mechanisms (ergosterol, β-(1,3) glucan and chitin production) regulating the antifungal activity of the rhizome extract were also examined. In the current study, phytochemical analysis of aqueous extracts of the roots, leaves, rhizomes and tubers showed that the rhizomes had the highest phenolic, saponin and tannin content when compared to the other plant organs. Fingerprinting by GC-MS revealed identical compounds in the different plant parts with the detection of 4 H Pyran-4-one DDMP (known antifungal), previously unreported in studies on T. violacea. The bulk of the extract comprised of 40% sulphur-containing and 20% furan-containing compounds. The remaining minor compounds comprised of 2x alcohols (13.3%), 1x pyran (6.7%), 1x ketone (6.7%), 1x halogen (6.7%) and 1x acid (6.7%) compounds. The rhizomes also had highest content of 2 methyl methioacetic acid, benzophenone and chloromethyl methylsulfide compared to the other plant parts. The rhizomes were found to be more potent against both pathogenic fungi tested here with an MIC and MFC of 1.25 mg/ml. Nystatin was included as a positive control when determining the MIC’s and MFC’s of the different plant extracts. The antifungal nature of the T. violacea extracts in the current study may be due to the synergistic effects of the sulphide, furan, pyran and ketone compounds present in the extracts, but this still remains to be verified in future studies. An investigation of the effects of an aqueous rhizome extract of T. violacea on Cryptococcus virulence factors showed that phospholipase activity of C. neoformans and C. gattii remained unaffected with increasing sub-lethal doses of the plant extract. There was significant reduction in urease production in both fungi in a dose dependent manner relative to the untreated cultures after 24 hr exposure to the extract. However, urease production reverted to normal after 48 hr post exposure implying that the cultures were able to recover due to temporary inhibition of urease activity. A significant decrease in melanin production was observed in both C. neoformans and C. gattii with increasing sub-inhibitory concentrations of the rhizome extract. Investigation of the effect of the plant extract on the ultrastucture of the fungi via Transmission Electron Microscopy showed the induction of cytomorphological changes in C. neoformans and C. gattii. Changes included thickening of the cell wall, an increase in the number of vacuoles, mitochondrial swelling and occasional detachment of the membrane from the cell wall. These changes suggest the activation of possible defence mechanisms to compensate for the loss of cellular materials or an effort to sequester toxic T. violacea components or toxic intermediates generated from inhibited cellular pathways. The capsule size and architecture remained unaltered in the presence of sub-lethal doses of the rhizome extract. To study the mechanism of action of the rhizome extract on ergosterol biosynthesis, total sterols were extracted and ergosterol, squalene, 2,3-oxidosqualene and lanosterol were quantified using Reverse Phase High Performance Liquid Chromatography. Ergosterol concentration declined in a dose dependent manner for both pathogenic yeasts similar to the positive control terbinafine, while there was a slight accumulation of squalene in C. gattii only. 2,3-oxidosqualene levels accumulated in both fungi relative to the untreated control. Lanosterol production showed an oscillatory trend for the two microorganisms. Together, these findings indicate that the rhizome extract is capable of inhibiting squalene epoxidase and 2,3-oxidosqualene/ lanosterol cyclase causing a decrease in ergosterol production.
- Full Text:
- Date Issued: 2018
- Authors: Mitradev, Pattoo
- Date: 2018
- Subjects: Violaceae -- Therapeutic use -- South Africa , Anticoagulants (Medicine) , Medicinal plants -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32772 , vital:32357
- Description: Cryptococcus neoformans and Cryptococcus gattii, which are environmental yeasts, are the etiological agents of cryptococcosis in both immunocompromised and immunocompetent individuals, and account for high mortality and morbidity rates in sub-Saharan Africa. The current antifungal agents used for treatment of cryptococcal infections either target the fungal cell wall (β-(1,3) glucan and chitin) or cell membrane directly or ergosterol biosynthetic pathways or fungal DNA and RNA. Gaps in antifungal therapy include the unavailability and exhorbitant costs of these drugs especially to patients in the developing world. Drug resistance to conventional drugs is also an ever-increasing problem. It is therefore essential to find alternative natural compounds from medicinal plants that are safer, cheaper and more widely available. Tulbaghia violacea, also known as wild garlic, has been used as a traditional remedy in South Africa for the treatment of several ailments. Aqueous and organic extracts of the plant have been demonstrated to have antimicrobial and antifungal activity against several pathogens. However, there is a huge gap in our current knowledge in that the mechanism/s of action/s of these extracts have not been fully investigated. The focus of the current study therefore was to determine whether T. violacea extracts from the roots, rhizome, leaves and tubers exhibited antifungal activity against C. neoformans and C. gattii and to evaluate the ability of the rhizome extract to induce changes in key fungal virulence factors. Three mechanisms (ergosterol, β-(1,3) glucan and chitin production) regulating the antifungal activity of the rhizome extract were also examined. In the current study, phytochemical analysis of aqueous extracts of the roots, leaves, rhizomes and tubers showed that the rhizomes had the highest phenolic, saponin and tannin content when compared to the other plant organs. Fingerprinting by GC-MS revealed identical compounds in the different plant parts with the detection of 4 H Pyran-4-one DDMP (known antifungal), previously unreported in studies on T. violacea. The bulk of the extract comprised of 40% sulphur-containing and 20% furan-containing compounds. The remaining minor compounds comprised of 2x alcohols (13.3%), 1x pyran (6.7%), 1x ketone (6.7%), 1x halogen (6.7%) and 1x acid (6.7%) compounds. The rhizomes also had highest content of 2 methyl methioacetic acid, benzophenone and chloromethyl methylsulfide compared to the other plant parts. The rhizomes were found to be more potent against both pathogenic fungi tested here with an MIC and MFC of 1.25 mg/ml. Nystatin was included as a positive control when determining the MIC’s and MFC’s of the different plant extracts. The antifungal nature of the T. violacea extracts in the current study may be due to the synergistic effects of the sulphide, furan, pyran and ketone compounds present in the extracts, but this still remains to be verified in future studies. An investigation of the effects of an aqueous rhizome extract of T. violacea on Cryptococcus virulence factors showed that phospholipase activity of C. neoformans and C. gattii remained unaffected with increasing sub-lethal doses of the plant extract. There was significant reduction in urease production in both fungi in a dose dependent manner relative to the untreated cultures after 24 hr exposure to the extract. However, urease production reverted to normal after 48 hr post exposure implying that the cultures were able to recover due to temporary inhibition of urease activity. A significant decrease in melanin production was observed in both C. neoformans and C. gattii with increasing sub-inhibitory concentrations of the rhizome extract. Investigation of the effect of the plant extract on the ultrastucture of the fungi via Transmission Electron Microscopy showed the induction of cytomorphological changes in C. neoformans and C. gattii. Changes included thickening of the cell wall, an increase in the number of vacuoles, mitochondrial swelling and occasional detachment of the membrane from the cell wall. These changes suggest the activation of possible defence mechanisms to compensate for the loss of cellular materials or an effort to sequester toxic T. violacea components or toxic intermediates generated from inhibited cellular pathways. The capsule size and architecture remained unaltered in the presence of sub-lethal doses of the rhizome extract. To study the mechanism of action of the rhizome extract on ergosterol biosynthesis, total sterols were extracted and ergosterol, squalene, 2,3-oxidosqualene and lanosterol were quantified using Reverse Phase High Performance Liquid Chromatography. Ergosterol concentration declined in a dose dependent manner for both pathogenic yeasts similar to the positive control terbinafine, while there was a slight accumulation of squalene in C. gattii only. 2,3-oxidosqualene levels accumulated in both fungi relative to the untreated control. Lanosterol production showed an oscillatory trend for the two microorganisms. Together, these findings indicate that the rhizome extract is capable of inhibiting squalene epoxidase and 2,3-oxidosqualene/ lanosterol cyclase causing a decrease in ergosterol production.
- Full Text:
- Date Issued: 2018
Biotic and abiotic drivers of macroinvertebrate assemblages in a South African river
- Authors: Bellingan, Terence Andrew
- Date: 2018
- Subjects: Aquatic insects -- South Africa -- Eastern Cape , Stream ecology -- South Africa -- Eastern Cape , Freshwater ecology -- South Africa -- Eastern Cape , Riparian areas -- Management , Ecosystem management -- South Africa -- Eastern Cape , Mayflies -- South Africa -- Eastern Cape , Stoneflies -- South Africa -- Eastern Cape , Keiskamma River
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/61839 , vital:28067
- Description: Aquatic insects are the most numerically abundant and diverse group of organisms found in lotic ecosystems in South Africa and the world over. They play vital roles in freshwater ecosystem functioning, processing nutrients and in turn forming integral links in stream food-webs. This thesis focussed on examining the macroinvertebrate fauna within three reaches of headwater streams of the Keiskamma River system: reaches that were considered to be fishless; reaches that were invaded by non-native salmonid species; and reaches that were dominated by native fish. I described the effects of predatory fish presence through detailed examination of macroinvertebrate assemblage composition; macroinvertebrate drift timing and density; and through niche utilisation determined from stable isotope data. Patterns in the macroinvertebrate assemblages of the headwaters of the Keiskamma River appear to be driven more strongly by flow rate and seasonal influences, but fish presence and biotope availability were also significant drivers. Niche shifts due to predator presence were not easy to detect and, while patterns of influence may have been evident, they were not found to be significant. However, I demonstrated that salmonids selectively feed on native fish species when the opportunity is presented, occupying significantly higher trophic levels when co-occurring with native fish than in invaded reaches where native fish are absent. Drift timing and density were demonstrated to be significantly different between reach for specific macroinvertebrate species from the Ephemeroptera and Plecoptera, under differing fish predation regimes, in agreement with what has been observed from studies in rivers elsewhere. In freshwater ecosystems of South Africa and worldwide, mitigation of negative effects of alien fishes through their removal using piscicides may also affect non-target organisms. To better understand the effects of just such a removal operation, employed for the first time in the history of freshwater conservation in South Africa, macroinvertebrate communities were assessed for non-target effects of rotenone. The fish eradication operations were demonstrated to have a short-term negative effect on the macroinvertebrate assemblage, through water quality index measurements and alteration of densities of macroinvertebrate taxa collected from stone surfaces. However, no long-term detrimental impact was observed as macroinvertebrate faunas returned to a comparable pre-treatment state within a year of each rotenone application.
- Full Text:
- Date Issued: 2018
- Authors: Bellingan, Terence Andrew
- Date: 2018
- Subjects: Aquatic insects -- South Africa -- Eastern Cape , Stream ecology -- South Africa -- Eastern Cape , Freshwater ecology -- South Africa -- Eastern Cape , Riparian areas -- Management , Ecosystem management -- South Africa -- Eastern Cape , Mayflies -- South Africa -- Eastern Cape , Stoneflies -- South Africa -- Eastern Cape , Keiskamma River
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/61839 , vital:28067
- Description: Aquatic insects are the most numerically abundant and diverse group of organisms found in lotic ecosystems in South Africa and the world over. They play vital roles in freshwater ecosystem functioning, processing nutrients and in turn forming integral links in stream food-webs. This thesis focussed on examining the macroinvertebrate fauna within three reaches of headwater streams of the Keiskamma River system: reaches that were considered to be fishless; reaches that were invaded by non-native salmonid species; and reaches that were dominated by native fish. I described the effects of predatory fish presence through detailed examination of macroinvertebrate assemblage composition; macroinvertebrate drift timing and density; and through niche utilisation determined from stable isotope data. Patterns in the macroinvertebrate assemblages of the headwaters of the Keiskamma River appear to be driven more strongly by flow rate and seasonal influences, but fish presence and biotope availability were also significant drivers. Niche shifts due to predator presence were not easy to detect and, while patterns of influence may have been evident, they were not found to be significant. However, I demonstrated that salmonids selectively feed on native fish species when the opportunity is presented, occupying significantly higher trophic levels when co-occurring with native fish than in invaded reaches where native fish are absent. Drift timing and density were demonstrated to be significantly different between reach for specific macroinvertebrate species from the Ephemeroptera and Plecoptera, under differing fish predation regimes, in agreement with what has been observed from studies in rivers elsewhere. In freshwater ecosystems of South Africa and worldwide, mitigation of negative effects of alien fishes through their removal using piscicides may also affect non-target organisms. To better understand the effects of just such a removal operation, employed for the first time in the history of freshwater conservation in South Africa, macroinvertebrate communities were assessed for non-target effects of rotenone. The fish eradication operations were demonstrated to have a short-term negative effect on the macroinvertebrate assemblage, through water quality index measurements and alteration of densities of macroinvertebrate taxa collected from stone surfaces. However, no long-term detrimental impact was observed as macroinvertebrate faunas returned to a comparable pre-treatment state within a year of each rotenone application.
- Full Text:
- Date Issued: 2018
Black South African men’s adjustment to divorce: a divorce-stress-adjustment model
- Muchena, Kudakwashe Christopher
- Authors: Muchena, Kudakwashe Christopher
- Date: 2018
- Subjects: Divorce -- Psychological aspects , Social psychology Men -- Psychology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/50121 , vital:42048
- Description: The decision to divorce marks a turning point for each individual involved. It can be viewed as more than just a legal process. From a psychological perspective, it does not matter who initiated the divorce, it always comes with emotional ramifications for all those involved. Statistically there is a high rate of divorce in South Africa and there have been significant shifts in trends over time. However, black South African men’s experience of, action in, and adjustment to divorce has been relatively neglected in the divorce research, yet it is important for understanding contemporary social arrangements and processes, as well as for broadening the understanding of black South African men’s lives. How black South African men describe their situations and respond to marital dissolution may point to their positions in the gender-structured community and to how they interpret the nature of social practice, marriages, divorce and their position in society. The present study aimed at exploring black South African men’s experience of, and adjustment to, divorce. More specifically, the study developed a divorce-stress-adjustment model for divorced black South African men. The theoretical framework underpinning this study was that of Symbolic Interactionism that was complemented and enhanced by Erikson’s Psychosocial Theory, focusing specifically on identity development in adulthood. This was a qualitative study using an Interpretative Phenomenological Analysis (IPA) as both the research design and data analytic theory and process. The eight participants were volunteers who were recruited purposively. In accordance with IPA guidelines, data for the study was collected using biographical questionnaires and semi-structured interviews. The emerging themes were grouped into four superordinate themes, that is, pre-divorce experiences, experiencing divorce, adjustment process and post-divorce experience. Each superordinate theme had corresponding subordinate themes and subthemes. The themes were then used to develop the divorce-stress adjustment model indicating that the experience of divorce is an interconnected process. Weed’s recommendations for interpretative synthesis of interview data were used.
- Full Text:
- Date Issued: 2018
- Authors: Muchena, Kudakwashe Christopher
- Date: 2018
- Subjects: Divorce -- Psychological aspects , Social psychology Men -- Psychology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/50121 , vital:42048
- Description: The decision to divorce marks a turning point for each individual involved. It can be viewed as more than just a legal process. From a psychological perspective, it does not matter who initiated the divorce, it always comes with emotional ramifications for all those involved. Statistically there is a high rate of divorce in South Africa and there have been significant shifts in trends over time. However, black South African men’s experience of, action in, and adjustment to divorce has been relatively neglected in the divorce research, yet it is important for understanding contemporary social arrangements and processes, as well as for broadening the understanding of black South African men’s lives. How black South African men describe their situations and respond to marital dissolution may point to their positions in the gender-structured community and to how they interpret the nature of social practice, marriages, divorce and their position in society. The present study aimed at exploring black South African men’s experience of, and adjustment to, divorce. More specifically, the study developed a divorce-stress-adjustment model for divorced black South African men. The theoretical framework underpinning this study was that of Symbolic Interactionism that was complemented and enhanced by Erikson’s Psychosocial Theory, focusing specifically on identity development in adulthood. This was a qualitative study using an Interpretative Phenomenological Analysis (IPA) as both the research design and data analytic theory and process. The eight participants were volunteers who were recruited purposively. In accordance with IPA guidelines, data for the study was collected using biographical questionnaires and semi-structured interviews. The emerging themes were grouped into four superordinate themes, that is, pre-divorce experiences, experiencing divorce, adjustment process and post-divorce experience. Each superordinate theme had corresponding subordinate themes and subthemes. The themes were then used to develop the divorce-stress adjustment model indicating that the experience of divorce is an interconnected process. Weed’s recommendations for interpretative synthesis of interview data were used.
- Full Text:
- Date Issued: 2018
Black South African men’s adjustment to divorce: a divorce-stress-adjustment model
- Muchena, Christopher Kudakwashe
- Authors: Muchena, Christopher Kudakwashe
- Date: 2018
- Subjects: Divorced men -- Psychological aspects , Adjustment (Psychology)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/17933 , vital:28543
- Description: The decision to divorce marks a turning point for each individual involved. It can be viewed as more than just a legal process. From a psychological perspective, it does not matter who initiated the divorce, it always comes with emotional ramifications for all those involved. Statistically there is a high rate of divorce in South Africa and there have been significant shifts in trends over time. However, black South African men’s experience of, action in, and adjustment to divorce has been relatively neglected in the divorce research, yet it is important for understanding contemporary social arrangements and processes, as well as for broadening the understanding of black South African men’s lives. How black South African men describe their situations and respond to marital dissolution may point to their positions in the gender-structured community and to how they interpret the nature of social practice, marriages, divorce and their position in society. The present study aimed at exploring black South African men’s experience of, and adjustment to, divorce. More specifically, the study developed a divorce-stress-adjustment model for divorced black South African men. The theoretical framework underpinning this study was that of Symbolic Interactionism that was complemented and enhanced by Erikson’s Psychosocial Theory, focusing specifically on identity development in adulthood. This was a qualitative study using an Interpretative Phenomenological Analysis (IPA) as both the research design and data analytic theory and process. The eight participants were volunteers who were recruited purposively. In accordance with IPA guidelines, data for the study was collected using biographical questionnaires and semi-structured interviews. The emerging themes were grouped into four superordinate themes, that is, pre-divorce experiences, experiencing divorce, adjustment process and post-divorce experience. Each superordinate theme had corresponding subordinate themes and subthemes. The themes were then used to develop the divorce-stress-adjustment model indicating that the experience of divorce is an interconnected process. Weed’s recommendations for interpretative synthesis of interview data were used.
- Full Text:
- Date Issued: 2018
- Authors: Muchena, Christopher Kudakwashe
- Date: 2018
- Subjects: Divorced men -- Psychological aspects , Adjustment (Psychology)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/17933 , vital:28543
- Description: The decision to divorce marks a turning point for each individual involved. It can be viewed as more than just a legal process. From a psychological perspective, it does not matter who initiated the divorce, it always comes with emotional ramifications for all those involved. Statistically there is a high rate of divorce in South Africa and there have been significant shifts in trends over time. However, black South African men’s experience of, action in, and adjustment to divorce has been relatively neglected in the divorce research, yet it is important for understanding contemporary social arrangements and processes, as well as for broadening the understanding of black South African men’s lives. How black South African men describe their situations and respond to marital dissolution may point to their positions in the gender-structured community and to how they interpret the nature of social practice, marriages, divorce and their position in society. The present study aimed at exploring black South African men’s experience of, and adjustment to, divorce. More specifically, the study developed a divorce-stress-adjustment model for divorced black South African men. The theoretical framework underpinning this study was that of Symbolic Interactionism that was complemented and enhanced by Erikson’s Psychosocial Theory, focusing specifically on identity development in adulthood. This was a qualitative study using an Interpretative Phenomenological Analysis (IPA) as both the research design and data analytic theory and process. The eight participants were volunteers who were recruited purposively. In accordance with IPA guidelines, data for the study was collected using biographical questionnaires and semi-structured interviews. The emerging themes were grouped into four superordinate themes, that is, pre-divorce experiences, experiencing divorce, adjustment process and post-divorce experience. Each superordinate theme had corresponding subordinate themes and subthemes. The themes were then used to develop the divorce-stress-adjustment model indicating that the experience of divorce is an interconnected process. Weed’s recommendations for interpretative synthesis of interview data were used.
- Full Text:
- Date Issued: 2018
Black women’s narratives of womanhood: before and after hysterectomy
- Kota-Nyati, Phumeza Patricia
- Authors: Kota-Nyati, Phumeza Patricia
- Date: 2018
- Subjects: Hysterectomy -- psychological aspects , Women -- psychological aspects Gender identity Intersectionality (Sociology)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/29995 , vital:30807
- Description: The removal of the uterus, medically referred to as a hysterectomy, is a permanent and irreversible procedure that potentially results in a number of immediate and significant effects. Performing a hysterectomy is at times the only medical option to a long and traumatic history of pelvic pains and surgeries. The decision to undergo this very costly, painful, and life-changing procedure can have an influence on the way women view themselves. Women’s narratives of womanhood before and after hysterectomy need to be understood within the context of women’s socially constructed identities. Gendered identity has been closely linked to genital and/or reproductive organs and the removal of these organs may influence the way women and societies define womanhood.The interpretive paradigm of constructionism with a narrative inquiry design was used as the lens to examine the women’s experiences. In-depth interviews were analysed through thematic analysis. The findings of this research revealed negative experiences resulting from severe symptoms before hysterectomy, exposed multi-layered structures of power and dominance during treatment, and indicated positive outcomes of hysterectomy. The findings should inform medical and allied practitioners regarding hysterectomy as a treatment option and add to the theoretical debate on the relationships between hysterectomy, womanhood, and identity.
- Full Text:
- Date Issued: 2018
- Authors: Kota-Nyati, Phumeza Patricia
- Date: 2018
- Subjects: Hysterectomy -- psychological aspects , Women -- psychological aspects Gender identity Intersectionality (Sociology)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/29995 , vital:30807
- Description: The removal of the uterus, medically referred to as a hysterectomy, is a permanent and irreversible procedure that potentially results in a number of immediate and significant effects. Performing a hysterectomy is at times the only medical option to a long and traumatic history of pelvic pains and surgeries. The decision to undergo this very costly, painful, and life-changing procedure can have an influence on the way women view themselves. Women’s narratives of womanhood before and after hysterectomy need to be understood within the context of women’s socially constructed identities. Gendered identity has been closely linked to genital and/or reproductive organs and the removal of these organs may influence the way women and societies define womanhood.The interpretive paradigm of constructionism with a narrative inquiry design was used as the lens to examine the women’s experiences. In-depth interviews were analysed through thematic analysis. The findings of this research revealed negative experiences resulting from severe symptoms before hysterectomy, exposed multi-layered structures of power and dominance during treatment, and indicated positive outcomes of hysterectomy. The findings should inform medical and allied practitioners regarding hysterectomy as a treatment option and add to the theoretical debate on the relationships between hysterectomy, womanhood, and identity.
- Full Text:
- Date Issued: 2018
Building IKhwezi, a digital platform to capture everyday Indigenous Knowledge for improving educational outcomes in marginalised communities
- Authors: Ntšekhe, Mathe V K
- Date: 2018
- Subjects: Information technology , Knowledge management , Traditional ecological knowledge , Pedagogical content knowledge , Traditional ecological knowledge -- Technological innovations , IKhwezi , ICT4D , Indigenous Technological Pedagogical Content Knowledge (I-TPACK) , Siyakhula Living Lab
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62505 , vital:28200
- Description: Aptly captured in the name, the broad mandate of Information and Communications Technologies for Development (ICT4D) is to facilitate the use of Information and Communication Technologies (ICTs) in society to support development. Education, as often stated, is the cornerstone for development, imparting knowledge for conceiving and realising development. In this thesis, we explore how everyday Indigenous Knowledge (IK) can be collected digitally, to enhance the educational outcomes of learners from marginalised backgrounds, by stimulating the production of teaching and learning materials that include the local imagery to have resonance with the learners. As part of the exploration, we reviewed a framework known as Technological Pedagogical Content Knowledge (TPACK), which spells out the different kinds of knowledge needed by teachers to teach effectively with ICTs. In this framework, IK is not present explicitly, but through the concept of context(s). Using Afrocentric and Pan-African scholarship, we argue that this logic is linked to colonialism and a critical decolonising pedagogy necessarily demands explication of IK: to make visible the cultures of the learners in the margins (e.g. Black rural learners). On the strength of this argument, we have proposed that TPACK be augumented to become Indigenous Technological Pedagogical Content Knowledge (I-TPACK). Through this augumentation, I-TPACK becomes an Afrocentric framework for a multicultural education in the digital era. The design of the digital platform for capturing IK relevant for formal education, was done in the Siyakhula Living Lab (SLL). The core idea of a Living Lab (LL) is that users must be understood in the context of their lived everyday reality. Further, they must be involved as co-creators in the design and innovation processes. On a methodological level, the LL environment allowed for the fusing together of multiple methods that can help to create a fitting solution. In this thesis, we followed an iterative user-centred methodology rooted in ethnography and phenomenology. Specifically, through long term conversations and interaction with teachers and ethnographic observations, we conceptualized a platform, IKhwezi, that facilitates the collection of context-sensitive content, collaboratively, and with cost and convenience in mind. We implemented this platform using MediaWiki, based on a number of considerations. From the ICT4D disciplinary point of view, a major consideration was being open to the possibility that other forms of innovation—and, not just ‘technovelty’ (i.e. technological/- technical innovation)—can provide a breakthrough or ingenious solution to the problem at hand. In a sense, we were reinforcing the growing sentiment within the discipline that technology is not the goal, but the means to foregrounding the commonality of the human experience in working towards development. Testing confirmed that there is some value in the platform. This is despite the challenges to onboard users, in pursuit of more content that could bolster the value of everyday IK in improving the educational outcomes of all learners.
- Full Text:
- Date Issued: 2018
- Authors: Ntšekhe, Mathe V K
- Date: 2018
- Subjects: Information technology , Knowledge management , Traditional ecological knowledge , Pedagogical content knowledge , Traditional ecological knowledge -- Technological innovations , IKhwezi , ICT4D , Indigenous Technological Pedagogical Content Knowledge (I-TPACK) , Siyakhula Living Lab
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62505 , vital:28200
- Description: Aptly captured in the name, the broad mandate of Information and Communications Technologies for Development (ICT4D) is to facilitate the use of Information and Communication Technologies (ICTs) in society to support development. Education, as often stated, is the cornerstone for development, imparting knowledge for conceiving and realising development. In this thesis, we explore how everyday Indigenous Knowledge (IK) can be collected digitally, to enhance the educational outcomes of learners from marginalised backgrounds, by stimulating the production of teaching and learning materials that include the local imagery to have resonance with the learners. As part of the exploration, we reviewed a framework known as Technological Pedagogical Content Knowledge (TPACK), which spells out the different kinds of knowledge needed by teachers to teach effectively with ICTs. In this framework, IK is not present explicitly, but through the concept of context(s). Using Afrocentric and Pan-African scholarship, we argue that this logic is linked to colonialism and a critical decolonising pedagogy necessarily demands explication of IK: to make visible the cultures of the learners in the margins (e.g. Black rural learners). On the strength of this argument, we have proposed that TPACK be augumented to become Indigenous Technological Pedagogical Content Knowledge (I-TPACK). Through this augumentation, I-TPACK becomes an Afrocentric framework for a multicultural education in the digital era. The design of the digital platform for capturing IK relevant for formal education, was done in the Siyakhula Living Lab (SLL). The core idea of a Living Lab (LL) is that users must be understood in the context of their lived everyday reality. Further, they must be involved as co-creators in the design and innovation processes. On a methodological level, the LL environment allowed for the fusing together of multiple methods that can help to create a fitting solution. In this thesis, we followed an iterative user-centred methodology rooted in ethnography and phenomenology. Specifically, through long term conversations and interaction with teachers and ethnographic observations, we conceptualized a platform, IKhwezi, that facilitates the collection of context-sensitive content, collaboratively, and with cost and convenience in mind. We implemented this platform using MediaWiki, based on a number of considerations. From the ICT4D disciplinary point of view, a major consideration was being open to the possibility that other forms of innovation—and, not just ‘technovelty’ (i.e. technological/- technical innovation)—can provide a breakthrough or ingenious solution to the problem at hand. In a sense, we were reinforcing the growing sentiment within the discipline that technology is not the goal, but the means to foregrounding the commonality of the human experience in working towards development. Testing confirmed that there is some value in the platform. This is despite the challenges to onboard users, in pursuit of more content that could bolster the value of everyday IK in improving the educational outcomes of all learners.
- Full Text:
- Date Issued: 2018
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
Chemical transformation and phytochemical studies of bioactive constituents from extract of callistemon citrinus (curtis) skeels
- Authors: Larayetan, Rotimi Abisoye
- Date: 2018
- Subjects: Callistemon Wild flowers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9122 , vital:34272
- Description: Callistemon citrinus belongs to the family Myrtaceae and exhibits therapeutic activities. The aerial parts of this plant are used to treat different ailments, among them are parasitic infections. The leaves, flowers and stems of Callistemon citrinus were subjected to hydrodistillation. The oils collected were studied by GC-MS analysis for the essential constituents. The overall phenolic content of the leaves oil, radical scavenging, antibacterial action and antioxidant activities of the essential oils of Callistemon citrinus were determined using standard methods, with free radical DPPH or ABTS as reference antioxidants. Chemical transformation of the components was examined for a whole year. A relationship between the chemical change in the volatile oil constituents, antioxidant capacity, percentage yield of the oil of Callistemon citrinus and fluctuation in season has been established. Active phytochemicals present in both ethyl acetate and methanolic extracts of Callistemon citrinus were determined spectrophotometrically. The antimicrobial properties, time of kill, and antioxidant activity of the extracts were explored. The bioactive components were characterized by high level of fatty acids. Squalene, a triterpenoid synthesized in human liver was obtained in the two extracts at varying amounts. The ethyl acetate extract demonstrated strong activity against P. aeruginosa ACC (28.7 ± 1.2 mm), Listeria ACC (26.0 ± 2.0 mm) and Escherichia coli ATCC 35150 (24.0 ± 3.5 mm). Qualitative phytochemical screening revealed the presence of alkaloids, glycosides, saponins, steroids and triterpenoids, fats and oils, flavonoids, phenols and tannins in them. In the quantitative phytochemical determination (total tannin, total flavonoids and flavonols, total phenolic and total antioxidant capacity) were carried out. The minimum time needed to kill the tested bacterial strains totally ranged from 15 to 24 hours. The aqueous extracts used for biosynthesis of nanoparticles were obtained from the fresh aerial parts of the plant. The biosynthesized gold and silver nanoparticles (AuNPs and AgNPs) of the aqueous extracts of the seed, flower and leaf of the plant, which are active as reducing and capping agents, were characterized using UV-VIS spectrophotometry, XRD, SEM, EDS, TEM, and FT IR. The XRD analysis revealed that the AgNPs were crystalline and the TEM showed that the shapes were spherical with an average size of 29 nm. For AuNPs, an average particle size of about 37 nm was confirmed by the TEM while the morphology and composition of the AuNPs were ascertained by SEM and EDS micrographs; uneven spherical shaped nanoparticles were established by the SEM. Both SEM and EDS demonstrated triangular shaped materials made up of silver and oxygen only. Absorption spectra confirmed by UV-VIS signify the dispersed nature of the synthesized nanoparticles with absorption band observed at 280 nm for the leaf AgNPs. FT IR had absorption bands at about 1700 cm-1 establishing the C=O stretching due to the amide bond while the FT IR for the AuNPs showed an absorption peak at 230 cm-1 confirming the presence of gold nanoparticles. The phytochemical investigation, isolation and characterization of the bioactive compounds of various organic crude extracts like hexane, dichloromethane, methanol and ethyl acetate were as well carried out, and the compounds responsible for their medicinal actions were determined. The results from different experiments revealed that the leaves and flowers of Callistemon citrinus possessed phenolic compounds and cyclic ethers with a variety of pharmacological action. The ethyl acetate and methanol crude extracts were found to possess broad spectrum of antimicrobial activities and pharmaceutically essential bioactive components with striking antioxidant capacities that may be used in the synthesis of novel drugs for the management of different ailments. The AuNPs and AgNPs synthesized from the seed, flower and leaf extracts of Callistemon citrinus where found to have prominent antimalarial, antiplasmodial, and antibacterial activities. The biosynthesized nanoparticles inhibit all the bacterial strains used and they were not cytotoxic to Hela cells, confirming their prospect for use as an excellent source for naturally occurring drugs against malaria, cell cytotoxicity, trypanosomes, and microbial infection. Similarly the crude organic extracts and the fractions derived from them exhibited high antimalarial and antitrypanosomal activities, but they were toxic to Hela cells. This is an indication that they will not be safe for use as targeted drugs for mammalian organism.
- Full Text:
- Date Issued: 2018
- Authors: Larayetan, Rotimi Abisoye
- Date: 2018
- Subjects: Callistemon Wild flowers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9122 , vital:34272
- Description: Callistemon citrinus belongs to the family Myrtaceae and exhibits therapeutic activities. The aerial parts of this plant are used to treat different ailments, among them are parasitic infections. The leaves, flowers and stems of Callistemon citrinus were subjected to hydrodistillation. The oils collected were studied by GC-MS analysis for the essential constituents. The overall phenolic content of the leaves oil, radical scavenging, antibacterial action and antioxidant activities of the essential oils of Callistemon citrinus were determined using standard methods, with free radical DPPH or ABTS as reference antioxidants. Chemical transformation of the components was examined for a whole year. A relationship between the chemical change in the volatile oil constituents, antioxidant capacity, percentage yield of the oil of Callistemon citrinus and fluctuation in season has been established. Active phytochemicals present in both ethyl acetate and methanolic extracts of Callistemon citrinus were determined spectrophotometrically. The antimicrobial properties, time of kill, and antioxidant activity of the extracts were explored. The bioactive components were characterized by high level of fatty acids. Squalene, a triterpenoid synthesized in human liver was obtained in the two extracts at varying amounts. The ethyl acetate extract demonstrated strong activity against P. aeruginosa ACC (28.7 ± 1.2 mm), Listeria ACC (26.0 ± 2.0 mm) and Escherichia coli ATCC 35150 (24.0 ± 3.5 mm). Qualitative phytochemical screening revealed the presence of alkaloids, glycosides, saponins, steroids and triterpenoids, fats and oils, flavonoids, phenols and tannins in them. In the quantitative phytochemical determination (total tannin, total flavonoids and flavonols, total phenolic and total antioxidant capacity) were carried out. The minimum time needed to kill the tested bacterial strains totally ranged from 15 to 24 hours. The aqueous extracts used for biosynthesis of nanoparticles were obtained from the fresh aerial parts of the plant. The biosynthesized gold and silver nanoparticles (AuNPs and AgNPs) of the aqueous extracts of the seed, flower and leaf of the plant, which are active as reducing and capping agents, were characterized using UV-VIS spectrophotometry, XRD, SEM, EDS, TEM, and FT IR. The XRD analysis revealed that the AgNPs were crystalline and the TEM showed that the shapes were spherical with an average size of 29 nm. For AuNPs, an average particle size of about 37 nm was confirmed by the TEM while the morphology and composition of the AuNPs were ascertained by SEM and EDS micrographs; uneven spherical shaped nanoparticles were established by the SEM. Both SEM and EDS demonstrated triangular shaped materials made up of silver and oxygen only. Absorption spectra confirmed by UV-VIS signify the dispersed nature of the synthesized nanoparticles with absorption band observed at 280 nm for the leaf AgNPs. FT IR had absorption bands at about 1700 cm-1 establishing the C=O stretching due to the amide bond while the FT IR for the AuNPs showed an absorption peak at 230 cm-1 confirming the presence of gold nanoparticles. The phytochemical investigation, isolation and characterization of the bioactive compounds of various organic crude extracts like hexane, dichloromethane, methanol and ethyl acetate were as well carried out, and the compounds responsible for their medicinal actions were determined. The results from different experiments revealed that the leaves and flowers of Callistemon citrinus possessed phenolic compounds and cyclic ethers with a variety of pharmacological action. The ethyl acetate and methanol crude extracts were found to possess broad spectrum of antimicrobial activities and pharmaceutically essential bioactive components with striking antioxidant capacities that may be used in the synthesis of novel drugs for the management of different ailments. The AuNPs and AgNPs synthesized from the seed, flower and leaf extracts of Callistemon citrinus where found to have prominent antimalarial, antiplasmodial, and antibacterial activities. The biosynthesized nanoparticles inhibit all the bacterial strains used and they were not cytotoxic to Hela cells, confirming their prospect for use as an excellent source for naturally occurring drugs against malaria, cell cytotoxicity, trypanosomes, and microbial infection. Similarly the crude organic extracts and the fractions derived from them exhibited high antimalarial and antitrypanosomal activities, but they were toxic to Hela cells. This is an indication that they will not be safe for use as targeted drugs for mammalian organism.
- Full Text:
- Date Issued: 2018
Co-Production of trust for effective local Governance: a case study of Nelson Mandela Bay Municipality
- Authors: Salie-Jakoet, Amina
- Date: 2018
- Subjects: Corporate governance--South Africa--Nelson Mandela Bay Municipality Economic development--South Africa--Nelson Mandela Bay Municipality , Municipal officials and employees--South Africa-- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20308 , vital:29228
- Description: This study acknowledged that while it might be true that protests often turn violent after formal channels have been exhausted, there is an underlying problem of lack of public participation, coproduction and a general lack of trust in and within local government institutions in South Africa. The study therefore proposes that public participation in the municipal governing process is more complex than anticipated. For purposes of data collection, a mixed methods research methodology was adopted and a number of salient recommendations are provided to address the levels of trust within local government. A normative model to enhance coproduction of trust between communities and local government has been proposed. The research is scientifically worthy of distribution to the broader academic community and a number of papers both nationally and internationally have been presented from it.
- Full Text:
- Date Issued: 2018
- Authors: Salie-Jakoet, Amina
- Date: 2018
- Subjects: Corporate governance--South Africa--Nelson Mandela Bay Municipality Economic development--South Africa--Nelson Mandela Bay Municipality , Municipal officials and employees--South Africa-- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20308 , vital:29228
- Description: This study acknowledged that while it might be true that protests often turn violent after formal channels have been exhausted, there is an underlying problem of lack of public participation, coproduction and a general lack of trust in and within local government institutions in South Africa. The study therefore proposes that public participation in the municipal governing process is more complex than anticipated. For purposes of data collection, a mixed methods research methodology was adopted and a number of salient recommendations are provided to address the levels of trust within local government. A normative model to enhance coproduction of trust between communities and local government has been proposed. The research is scientifically worthy of distribution to the broader academic community and a number of papers both nationally and internationally have been presented from it.
- Full Text:
- Date Issued: 2018
Co-production of trust for effective local governance: a case study of the Nelson Mandela Bay Municipality
- Authors: Jakoet-Salie, Amina
- Date: 2018
- Subjects: Public participation -- South Africa -- Nelson Mandela Bay Local government -- South Africa -- Nelson Mandela Bay
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20297 , vital:29227
- Description: The primary aim of this study was to establish whether co-production of public services will lead to trust in service delivery and ultimately to trust in government, with specific reference to the Nelson Mandela Bay Municipality (NMBM). Furthermore, this research investigatedthe fundamental reasons for the mistrust in government, in lieu of the ongoing service delivery protests and officials who are at times not held accountable for their actions. This study acknowledges that there is an underlying problem of lack ofpublic participation and co-production at the sphere of local government.This research is solely based on the assumption thatif co-production is non-existent or problematic and if communities lose trust in the performance of municipalities, any attempts by the government to address these challenges relating to effective governance would be ineffective.The studyprovidesan in-depth theoretical review on co-production, public participation, citizen engagement and trust, with reference to both the national and international context. The study employed both quantitative and qualitative research approaches to validate the research questions and authenticate the problem statement. The triangulation approach allowed the researcher to effectively engage the strengths of both research methodologies. The research findings from the empirical survey were statistically analysed using statistical procedures. The data analysis, derived from the qualitative research approach, involved thematic content analysis. The sample populations for the study comprised councillors selected senior officials and ward committee members. For the quantitative approach, questionnaires were employed for the councillors and the officials. Focus group interviews were conducted with ward committee members as the qualitative component of the study. The findings of the study revealed that as a result of communities’ increasing lack of trust and confidence in local government, service delivery protests are increasing.The study further indicated thatcommunities in the NMBM are generally not well informed about the development plans of the municipality and do not adequately participate in local government activities.The findings from the focus group interviewsconcluded that the working relationship between the ward councillors and ward committee members was somewhat strained and this could have a negative impact on service delivery and ultimately trust levels.Recommendations emanating from the empirical survey and focus group interviews are presented to promote public participation and co-production which essentially could lead to an increase in trust in local government. Legislative prescriptions require that communitiesshould actively participate in the decision-making processes at the local sphere of government. In this regard, a normative model is proposed to further enhance this requirement.
- Full Text:
- Date Issued: 2018
- Authors: Jakoet-Salie, Amina
- Date: 2018
- Subjects: Public participation -- South Africa -- Nelson Mandela Bay Local government -- South Africa -- Nelson Mandela Bay
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20297 , vital:29227
- Description: The primary aim of this study was to establish whether co-production of public services will lead to trust in service delivery and ultimately to trust in government, with specific reference to the Nelson Mandela Bay Municipality (NMBM). Furthermore, this research investigatedthe fundamental reasons for the mistrust in government, in lieu of the ongoing service delivery protests and officials who are at times not held accountable for their actions. This study acknowledges that there is an underlying problem of lack ofpublic participation and co-production at the sphere of local government.This research is solely based on the assumption thatif co-production is non-existent or problematic and if communities lose trust in the performance of municipalities, any attempts by the government to address these challenges relating to effective governance would be ineffective.The studyprovidesan in-depth theoretical review on co-production, public participation, citizen engagement and trust, with reference to both the national and international context. The study employed both quantitative and qualitative research approaches to validate the research questions and authenticate the problem statement. The triangulation approach allowed the researcher to effectively engage the strengths of both research methodologies. The research findings from the empirical survey were statistically analysed using statistical procedures. The data analysis, derived from the qualitative research approach, involved thematic content analysis. The sample populations for the study comprised councillors selected senior officials and ward committee members. For the quantitative approach, questionnaires were employed for the councillors and the officials. Focus group interviews were conducted with ward committee members as the qualitative component of the study. The findings of the study revealed that as a result of communities’ increasing lack of trust and confidence in local government, service delivery protests are increasing.The study further indicated thatcommunities in the NMBM are generally not well informed about the development plans of the municipality and do not adequately participate in local government activities.The findings from the focus group interviewsconcluded that the working relationship between the ward councillors and ward committee members was somewhat strained and this could have a negative impact on service delivery and ultimately trust levels.Recommendations emanating from the empirical survey and focus group interviews are presented to promote public participation and co-production which essentially could lead to an increase in trust in local government. Legislative prescriptions require that communitiesshould actively participate in the decision-making processes at the local sphere of government. In this regard, a normative model is proposed to further enhance this requirement.
- Full Text:
- Date Issued: 2018
Code-switching as a pedagogical strategy in classroom settings: the case of township schools in a South African Metropolitan Municipality
- Authors: Marawu, Sithembele
- Date: 2018
- Subjects: Code switching (Linguistics) , Multilingual education -- South Africa , Education, Bilingual -- South Africa , Language and languages -- Study and teaching -- Bilingual method , English language -- Social aspects -- South Africa , Language and education -- South Africa , Language and education -- Social aspects -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62406 , vital:28173
- Description: The purpose of this study was to explore the use of code-switching as a pedagogical strategy in bi/multilingual classroom settings. It was prompted by the widespread use of codeswitching (CS) in classrooms, particularly in South African rural and township schools. This study highlighted that learners from disadvantaged backgrounds struggle to learn through the medium of English but aspire to acquire it because of its association with socio-economic advancement. However, poor proficiency in English excludes them from being part of the country's economy. Research studies show that there is a shift from the old orthodoxy which perceived CS as undesirable in classrooms to a new orthodoxy that acknowledges its academic contribution in classrooms. Although more research on classroom CS has been done, this study identified the need for development of new strategies on how to use CS effectively in classrooms as a linguistic and pedagogical resource. In line with critical classroom ethnography, qualitative interpretation of data was used to understand the teachers' discourse behaviour. Additionally, non-probability sampling - specifically purposive sampling - was used to collect data. These methods and approaches assisted in the analysis of the discourse of the three teachers who served as units of analysis in this study. These teachers relied on CS to impart the content of their subjects to the learners. It transpired from data analysis that teachers use CS in classrooms to achieve various functions like social and pedagogical functions. Another finding is that the switches teachers make do not affect the syntactic structure of the matrix language. Moreover, CS enhances understanding of the subject matter. This study concludes by stating that as learners are emergent bilinguals, additive bilingualism would be more ideal in the South African situation than subtractive bilingualism which parents and learners seem to prefer. Lastly, there is a need to harness CS as a communicative and pedagogical resource in classrooms.
- Full Text:
- Date Issued: 2018
- Authors: Marawu, Sithembele
- Date: 2018
- Subjects: Code switching (Linguistics) , Multilingual education -- South Africa , Education, Bilingual -- South Africa , Language and languages -- Study and teaching -- Bilingual method , English language -- Social aspects -- South Africa , Language and education -- South Africa , Language and education -- Social aspects -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62406 , vital:28173
- Description: The purpose of this study was to explore the use of code-switching as a pedagogical strategy in bi/multilingual classroom settings. It was prompted by the widespread use of codeswitching (CS) in classrooms, particularly in South African rural and township schools. This study highlighted that learners from disadvantaged backgrounds struggle to learn through the medium of English but aspire to acquire it because of its association with socio-economic advancement. However, poor proficiency in English excludes them from being part of the country's economy. Research studies show that there is a shift from the old orthodoxy which perceived CS as undesirable in classrooms to a new orthodoxy that acknowledges its academic contribution in classrooms. Although more research on classroom CS has been done, this study identified the need for development of new strategies on how to use CS effectively in classrooms as a linguistic and pedagogical resource. In line with critical classroom ethnography, qualitative interpretation of data was used to understand the teachers' discourse behaviour. Additionally, non-probability sampling - specifically purposive sampling - was used to collect data. These methods and approaches assisted in the analysis of the discourse of the three teachers who served as units of analysis in this study. These teachers relied on CS to impart the content of their subjects to the learners. It transpired from data analysis that teachers use CS in classrooms to achieve various functions like social and pedagogical functions. Another finding is that the switches teachers make do not affect the syntactic structure of the matrix language. Moreover, CS enhances understanding of the subject matter. This study concludes by stating that as learners are emergent bilinguals, additive bilingualism would be more ideal in the South African situation than subtractive bilingualism which parents and learners seem to prefer. Lastly, there is a need to harness CS as a communicative and pedagogical resource in classrooms.
- Full Text:
- Date Issued: 2018
Combined spectral and stimulated luminescence study of charge trapping and recombination processes in α-Al2O3:C
- Authors: Nyirenda, Angel Newton
- Date: 2018
- Subjects: Luminescence , Thermoluminescence , Luminescence spectroscopy , Carbon-doped aluminium oxide , Radioluminescence , Time-resolved X-ray excited optical luminescence
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62683 , vital:28235
- Description: The main objective of this project was to gain a deeper and better understanding of the luminescence processes in a-Al₂O₃:C, a highly-sensitive dosimetric material, using a combined spectral and stimulated luminescence study. The spectral studies concentrated on the emission spectra obtained using X-ray induced radioluminescence (XERL), thermoluminescence (XETL) and time-resolved X-ray excited optical luminescence (TR-XEOL) techniques. The stimulated luminescence studies were based on thermoluminescence (TL), optically stimulated luminescence (OSL) and phototransferred TL (PTTL) methods that were used in the study of the radiation-induced defects at high beta-doses and the deep traps, that is, traps with thermal depths beyond 500°C. The spectral and stimulated luminescence measurements were carried out using a high sensitivity luminescence spectrometer and a Ris0 TL/OSL Model DA-20 Reader, respectively. The XERL emission spectrum measured at room temperature shows seven gaussian peaks associated with F-centres (420 nm), F+-centres (334 nm), F2+-centres (559 nm), Stoke’s vibronic band of Cr3+ (671 nm), Cr3+ R-line emission (694 nm), anti-Stokes vibronic band of Cr3+ (710 nm) and an unidentified emission band (260-300 nm) which we associate with hole recombinations at a luminescence centre. The 694-nm R-line emission from Cr3+ impurity ions is most likely due to recombination of holes at Cr2+ during stimulated luminescence and as a result of an intracentre excitation of Cr3+ in photoluminescence (PL) due to photon absorption. The Cr3+ emission decreases in intensity, whereas the intensity of F-centre emission band is almost constant with repeated XERL measurements. Depending on the amount of X-ray irradiation dose, both holes and/or electrons may take place in the emission processes of peaks I (30-80°C), II (90-250°C) and III (250-320°C) during a TL readout, albeit, electron recombination is dominant regardless of dose. At higher doses, the XETL emission spectra indicate that the dominant band associated with TL peak III (250-320°C) in the material, shifts from F-centre to Cr3+. Using the deep-traps OSL, it has been confirmed that the main TL trap is also the main OSL trap whereas the TL traps lying in the temperature range of 400-550°C constitute the secondary OSL traps. There is evidence of strong retrapping at the main trap during optical stimulation of charges from the secondary OSL traps and the deep traps and that the retrapping occurs via the delocalized bands. At high-irradiation beta-doses, aggregate defect centres which significantly alter the TL and OSL properties, are induced in the material. The induced aggregate centres get completely obliterated by heating a sample to 700°C. The radiation-induced defects cause the main TL peak to shift towards higher temperatures, increase its FWHM, reduce its maximum intensity and cause an underestimation of both the activation energy and order of kinetics of the peak. On the other hand, the OSL response of the material is enhanced following a high-irradiation dose. During sample storage in the dark at ambient temperature, charges do migrate from the deep traps (donors) to the main and intermediate traps (acceptors) and that the major donor traps during this charge transfer phenomenon lie between 500-600°C.
- Full Text:
- Date Issued: 2018
- Authors: Nyirenda, Angel Newton
- Date: 2018
- Subjects: Luminescence , Thermoluminescence , Luminescence spectroscopy , Carbon-doped aluminium oxide , Radioluminescence , Time-resolved X-ray excited optical luminescence
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62683 , vital:28235
- Description: The main objective of this project was to gain a deeper and better understanding of the luminescence processes in a-Al₂O₃:C, a highly-sensitive dosimetric material, using a combined spectral and stimulated luminescence study. The spectral studies concentrated on the emission spectra obtained using X-ray induced radioluminescence (XERL), thermoluminescence (XETL) and time-resolved X-ray excited optical luminescence (TR-XEOL) techniques. The stimulated luminescence studies were based on thermoluminescence (TL), optically stimulated luminescence (OSL) and phototransferred TL (PTTL) methods that were used in the study of the radiation-induced defects at high beta-doses and the deep traps, that is, traps with thermal depths beyond 500°C. The spectral and stimulated luminescence measurements were carried out using a high sensitivity luminescence spectrometer and a Ris0 TL/OSL Model DA-20 Reader, respectively. The XERL emission spectrum measured at room temperature shows seven gaussian peaks associated with F-centres (420 nm), F+-centres (334 nm), F2+-centres (559 nm), Stoke’s vibronic band of Cr3+ (671 nm), Cr3+ R-line emission (694 nm), anti-Stokes vibronic band of Cr3+ (710 nm) and an unidentified emission band (260-300 nm) which we associate with hole recombinations at a luminescence centre. The 694-nm R-line emission from Cr3+ impurity ions is most likely due to recombination of holes at Cr2+ during stimulated luminescence and as a result of an intracentre excitation of Cr3+ in photoluminescence (PL) due to photon absorption. The Cr3+ emission decreases in intensity, whereas the intensity of F-centre emission band is almost constant with repeated XERL measurements. Depending on the amount of X-ray irradiation dose, both holes and/or electrons may take place in the emission processes of peaks I (30-80°C), II (90-250°C) and III (250-320°C) during a TL readout, albeit, electron recombination is dominant regardless of dose. At higher doses, the XETL emission spectra indicate that the dominant band associated with TL peak III (250-320°C) in the material, shifts from F-centre to Cr3+. Using the deep-traps OSL, it has been confirmed that the main TL trap is also the main OSL trap whereas the TL traps lying in the temperature range of 400-550°C constitute the secondary OSL traps. There is evidence of strong retrapping at the main trap during optical stimulation of charges from the secondary OSL traps and the deep traps and that the retrapping occurs via the delocalized bands. At high-irradiation beta-doses, aggregate defect centres which significantly alter the TL and OSL properties, are induced in the material. The induced aggregate centres get completely obliterated by heating a sample to 700°C. The radiation-induced defects cause the main TL peak to shift towards higher temperatures, increase its FWHM, reduce its maximum intensity and cause an underestimation of both the activation energy and order of kinetics of the peak. On the other hand, the OSL response of the material is enhanced following a high-irradiation dose. During sample storage in the dark at ambient temperature, charges do migrate from the deep traps (donors) to the main and intermediate traps (acceptors) and that the major donor traps during this charge transfer phenomenon lie between 500-600°C.
- Full Text:
- Date Issued: 2018
Compensation for distribution of timing and reference signals over optical fibre networks for telescope arrays
- Authors: Wassin, Shukree
- Date: 2018
- Subjects: Fiber optics , Optical communications Very large array telescopes Optical fiber detectors
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36425 , vital:33941
- Description: Significant advancements and developments have been made in optical frequency standards, in recent years. In order to verify the accuracy and preciseness of the disseminated RF signal, it is essential to compare its stability with the standards provided in literature as well as by metrology institutes. However, conventional frequency comparison techniques via satellites have extremely inferior stability qualities. As a result, the need for an alternative ultra-high precision RF transfer method presented itself. Highly accurate and precise frequency dissemination across optical fiber has proved a leading contender and a possible solution. When compared to conventional data transfer media, optical fiber has proven to be more superior and yields lower transmission errors and is immune to radio frequency interference. A further quality of optical fibre is that its transmission distance can be extended to greater degree than the traditional coaxial cable due to its low loss property. This thesis deals with the compensation of phase noise in single mode optical fibre. Phase noise degrades the performance and stability of the RF signal as well as the optical carrier frequency across long-haul optical networks. This work begins by experimentally demonstrating a unique and novel way for measuring the round-trip optical fibre latency times. The technique is based on all optical wavelength conversion using a stable PPS injection signal. The result highlighted the importance for active phase error compensation along a fibre link. Various computer simulations were used to study the influence of temperature fluctuation on the optical fibre. The first ever error signals generated at NMU was experimentally demonstrated. Results illustrated that, by minimizing the error voltage the phase difference between the transmitted and reference signals were reduced to zero. Performance analysis testing of the VCSEL phase correction actuator showed that majority of the dither iterations that induced the phase compensation took approximately 0.15 s. Residual frequency instabilities of 3.39791 x 10-12 at 1 s and 8.14848 x 10-12 at 103 s was measured when the 26 km G.655 fibre link was running freely. Experimental results further showed that the relative frequency stabilities measured at 1 s and 103 s were 4.43902 x 10-12 and 1.62055 x 10-13 during active compensation, respectively. The novel work presented in this thesis is exciting since the VCSEL is used as the optical source as well as the phase correction actuator. The benefits of such a device is that is reduces system costs and complexities.
- Full Text:
- Date Issued: 2018
- Authors: Wassin, Shukree
- Date: 2018
- Subjects: Fiber optics , Optical communications Very large array telescopes Optical fiber detectors
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36425 , vital:33941
- Description: Significant advancements and developments have been made in optical frequency standards, in recent years. In order to verify the accuracy and preciseness of the disseminated RF signal, it is essential to compare its stability with the standards provided in literature as well as by metrology institutes. However, conventional frequency comparison techniques via satellites have extremely inferior stability qualities. As a result, the need for an alternative ultra-high precision RF transfer method presented itself. Highly accurate and precise frequency dissemination across optical fiber has proved a leading contender and a possible solution. When compared to conventional data transfer media, optical fiber has proven to be more superior and yields lower transmission errors and is immune to radio frequency interference. A further quality of optical fibre is that its transmission distance can be extended to greater degree than the traditional coaxial cable due to its low loss property. This thesis deals with the compensation of phase noise in single mode optical fibre. Phase noise degrades the performance and stability of the RF signal as well as the optical carrier frequency across long-haul optical networks. This work begins by experimentally demonstrating a unique and novel way for measuring the round-trip optical fibre latency times. The technique is based on all optical wavelength conversion using a stable PPS injection signal. The result highlighted the importance for active phase error compensation along a fibre link. Various computer simulations were used to study the influence of temperature fluctuation on the optical fibre. The first ever error signals generated at NMU was experimentally demonstrated. Results illustrated that, by minimizing the error voltage the phase difference between the transmitted and reference signals were reduced to zero. Performance analysis testing of the VCSEL phase correction actuator showed that majority of the dither iterations that induced the phase compensation took approximately 0.15 s. Residual frequency instabilities of 3.39791 x 10-12 at 1 s and 8.14848 x 10-12 at 103 s was measured when the 26 km G.655 fibre link was running freely. Experimental results further showed that the relative frequency stabilities measured at 1 s and 103 s were 4.43902 x 10-12 and 1.62055 x 10-13 during active compensation, respectively. The novel work presented in this thesis is exciting since the VCSEL is used as the optical source as well as the phase correction actuator. The benefits of such a device is that is reduces system costs and complexities.
- Full Text:
- Date Issued: 2018
Critical assessment of the human resource capacity needs of senior management at Thaba Chweu Municipality in Mpumalanga Province, South Africa
- Authors: Dube, Boy David
- Date: 2018
- Subjects: Municipal government Rural poor Senior leadership teams
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/12172 , vital:39193
- Description: The terrain of local government is not only very complex, dynamic, and challenging, but also very unique. The quality of human resources is vital in a public institution, particularly in institutions that are meant to service communities by providing sustainable basic services. Amongst the concerns raised at a municipal level are the lack of professionalism and the required competency and capacity amongst the workforce that must perform the actual duties of servicing the local communities. This study was aimed at identifying and analysing human resource development and human resource management policies, strategies and needs in line with the current circumstances and conditions at a particular municipality. A series of challenges (that a number of community members, newspaper articles, community leaders and both the Mpumalanga Provincial Government and other spheres of government raised and complained about) prompted this study. Constant complaints are leveled against municipalities about appropriate and well qualified candidates being overlooked for employment opportunities at the expense of nepotism, cronyism and blatant corrupt activities. This study is a combination of both quantitative and qualitative methods. In line with the quantitative method of generating and assembling information, the researcher used the judgement sampling method. Questionnaires were administered to collect quantitative data while primary data was collected via interviews. Data was obtained from 45 participants in Thaba Chweu Municipality. The findings show that the majority of respondents (in the form of percentages) spoke against the capacity of the officials. A smaller percentage spoke in favour of the availability of capacity. These respondents stated that municipal officials have the required skills and capacity to perform their duties. Furthermore, the study found that there was inconsistency in the implementation of council resolutions and interference in administrative matters. These factors compromised achieving the objectives of the municipal strategies and policies. The study recommends that the municipality ensures that the human resource management and development departments are consonant with current and modernised needs and that delegations to line functionaries are properly assigned and documented.
- Full Text:
- Date Issued: 2018
- Authors: Dube, Boy David
- Date: 2018
- Subjects: Municipal government Rural poor Senior leadership teams
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/12172 , vital:39193
- Description: The terrain of local government is not only very complex, dynamic, and challenging, but also very unique. The quality of human resources is vital in a public institution, particularly in institutions that are meant to service communities by providing sustainable basic services. Amongst the concerns raised at a municipal level are the lack of professionalism and the required competency and capacity amongst the workforce that must perform the actual duties of servicing the local communities. This study was aimed at identifying and analysing human resource development and human resource management policies, strategies and needs in line with the current circumstances and conditions at a particular municipality. A series of challenges (that a number of community members, newspaper articles, community leaders and both the Mpumalanga Provincial Government and other spheres of government raised and complained about) prompted this study. Constant complaints are leveled against municipalities about appropriate and well qualified candidates being overlooked for employment opportunities at the expense of nepotism, cronyism and blatant corrupt activities. This study is a combination of both quantitative and qualitative methods. In line with the quantitative method of generating and assembling information, the researcher used the judgement sampling method. Questionnaires were administered to collect quantitative data while primary data was collected via interviews. Data was obtained from 45 participants in Thaba Chweu Municipality. The findings show that the majority of respondents (in the form of percentages) spoke against the capacity of the officials. A smaller percentage spoke in favour of the availability of capacity. These respondents stated that municipal officials have the required skills and capacity to perform their duties. Furthermore, the study found that there was inconsistency in the implementation of council resolutions and interference in administrative matters. These factors compromised achieving the objectives of the municipal strategies and policies. The study recommends that the municipality ensures that the human resource management and development departments are consonant with current and modernised needs and that delegations to line functionaries are properly assigned and documented.
- Full Text:
- Date Issued: 2018
Cross-Border Migration, Social Cohesion and African Continental Integration: Perspectives of African Immigrants and South African Nationals in Gauteng, South Africa
- Authors: Maseng, Jonathan Oshupeng
- Date: 2018
- Subjects: Migration -- Africa Emigration and immigration Social integration
- Language: English
- Type: Thesis , Doctoral , PhD(Sociology)
- Identifier: http://hdl.handle.net/10353/8855 , vital:33673
- Description: Using the Sunnyside suburb of South Africa’s capital city of Pretoria as a case study, this study sought to gather, analyse and engage the perspectives, narratives and idealisations of African migrants and South African nationals in Gauteng province on cross-border migration, social cohesion and African continental integration. The goal was to interrogate the dominant discourse and assumption in migration scholarship that contact between nationals and immigrants is inherently conflict-inducing. The study adopted a qualitative methodology, with in-depth interviews, “street ethnography”, expert interviews and document analysis as the main sources of primary data. Overall, 85 in-depth interviews were conducted with immigrants and nationals of different occupational, gender and class backgrounds. The study found, among other things, that while many respondents expressed negative sentiments with regard to how cross-border migration affected their experience of social cohesion and idealisations about African continental integration, the relations between African immigrants and South African nationals in the study area were overwhelmingly congenial. This was even when there was no policy-oriented action by government to promote these positive relations. Respondents attributed this congeniality to, among other things, the fact that most small immigrant businesses depended on a predominantly South African clientele, while South African nationals in the study area saw such businesses as filling a crucial gap in their immediate socio-economic environments. Importantly, service provider-client relations served as “enhancers” of social cohesion in the study area. On the other hand, the relative dominance of immigrants in the small business sector in the study area served as a “threat” to social cohesion. From these findings, the study concluded that, contact between immigrants and nationals was not necessarily inherently conflict-inducing, and that social cohesion also rested on the logic of mutual dependence.
- Full Text:
- Date Issued: 2018
- Authors: Maseng, Jonathan Oshupeng
- Date: 2018
- Subjects: Migration -- Africa Emigration and immigration Social integration
- Language: English
- Type: Thesis , Doctoral , PhD(Sociology)
- Identifier: http://hdl.handle.net/10353/8855 , vital:33673
- Description: Using the Sunnyside suburb of South Africa’s capital city of Pretoria as a case study, this study sought to gather, analyse and engage the perspectives, narratives and idealisations of African migrants and South African nationals in Gauteng province on cross-border migration, social cohesion and African continental integration. The goal was to interrogate the dominant discourse and assumption in migration scholarship that contact between nationals and immigrants is inherently conflict-inducing. The study adopted a qualitative methodology, with in-depth interviews, “street ethnography”, expert interviews and document analysis as the main sources of primary data. Overall, 85 in-depth interviews were conducted with immigrants and nationals of different occupational, gender and class backgrounds. The study found, among other things, that while many respondents expressed negative sentiments with regard to how cross-border migration affected their experience of social cohesion and idealisations about African continental integration, the relations between African immigrants and South African nationals in the study area were overwhelmingly congenial. This was even when there was no policy-oriented action by government to promote these positive relations. Respondents attributed this congeniality to, among other things, the fact that most small immigrant businesses depended on a predominantly South African clientele, while South African nationals in the study area saw such businesses as filling a crucial gap in their immediate socio-economic environments. Importantly, service provider-client relations served as “enhancers” of social cohesion in the study area. On the other hand, the relative dominance of immigrants in the small business sector in the study area served as a “threat” to social cohesion. From these findings, the study concluded that, contact between immigrants and nationals was not necessarily inherently conflict-inducing, and that social cohesion also rested on the logic of mutual dependence.
- Full Text:
- Date Issued: 2018
Decentralization and quality assurance in the Ugandan primary education sector
- Authors: Abu-Baker, Mutaaya Sirajee
- Date: 2018
- Subjects: Schools -- Decentralization -- Uganda , Education, Primary -- Uganda , Educational change -- Uganda
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/57390 , vital:26897
- Description: The study presented in this thesis is a case study analysis of decentralization and quality assurance in a decentralized set up of the Ugandan Primary Schooling. The research looked at how the monitoring and evaluation informed the policy formulation process to regulate quality assurance in a decentralized governance of primary education. The Study was positioned in the critical realist paradigm, interpretive in orientation and used both coding and thematic techniques to understand the teachers’, SMC members’, and officers’ (at district and ministry levels) experiences and perceptions of quality assurance in a decentralized set up. Data was gathered using interviews, document analysis and observation methods. The findings indicated that the study was affected by eleven themes: Management System and Leadership, Human Resource Management, Finance Administration and Management, Parenting and Nutrition, Politics, Motivation, Social Structures and Patterns, Legislative Process and Policies, Infrastructure Development and Management, Community Involvement in Education and Curriculum and Professionalism. The monitoring and evaluation system had a framework in which it operates, though there was no quality assurance policy to guide the provision of quality education. The study finally indicated that there are more threats in a decentralized set up that put Quality in danger. Secondly, there was absence of supervision/inspection in schools as there was no evidence to prove this due to absence of reports. However, document analysis indicated visits of officers to schools. Records management was a problem to schools. Decentralization was adopted at different levels by different countries to address specific problems identified in view of service delivery. Finally, though monitoring and evaluation results informed the policy and decision makers, there was no quality assurance policy to guide the provision of quality education in institutions.
- Full Text:
- Date Issued: 2018
- Authors: Abu-Baker, Mutaaya Sirajee
- Date: 2018
- Subjects: Schools -- Decentralization -- Uganda , Education, Primary -- Uganda , Educational change -- Uganda
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/57390 , vital:26897
- Description: The study presented in this thesis is a case study analysis of decentralization and quality assurance in a decentralized set up of the Ugandan Primary Schooling. The research looked at how the monitoring and evaluation informed the policy formulation process to regulate quality assurance in a decentralized governance of primary education. The Study was positioned in the critical realist paradigm, interpretive in orientation and used both coding and thematic techniques to understand the teachers’, SMC members’, and officers’ (at district and ministry levels) experiences and perceptions of quality assurance in a decentralized set up. Data was gathered using interviews, document analysis and observation methods. The findings indicated that the study was affected by eleven themes: Management System and Leadership, Human Resource Management, Finance Administration and Management, Parenting and Nutrition, Politics, Motivation, Social Structures and Patterns, Legislative Process and Policies, Infrastructure Development and Management, Community Involvement in Education and Curriculum and Professionalism. The monitoring and evaluation system had a framework in which it operates, though there was no quality assurance policy to guide the provision of quality education. The study finally indicated that there are more threats in a decentralized set up that put Quality in danger. Secondly, there was absence of supervision/inspection in schools as there was no evidence to prove this due to absence of reports. However, document analysis indicated visits of officers to schools. Records management was a problem to schools. Decentralization was adopted at different levels by different countries to address specific problems identified in view of service delivery. Finally, though monitoring and evaluation results informed the policy and decision makers, there was no quality assurance policy to guide the provision of quality education in institutions.
- Full Text:
- Date Issued: 2018
Design of a dedicated IFT microcontroller
- Authors: Himunzowa, Grayson
- Date: 2018
- Subjects: Feedback control systems , Automatic control , Engineering design -- Data processing
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30017 , vital:30809
- Description: The design of a Dedicated IFT Microcontroller originated from the successful implementation of the Iterative Feedback Tuning (IFT) technique into the Digital Signal Processor microcontroller (DSP56F807C) at the University of Cape Town in 2006. However, implementation of the IFT technique on a general-purpose microcontroller is neither optimal, nor a cost-effective exercise, as most of the microcontroller peripherals remain unused, and drain energy for doing nothing. In addition, microcontrollers and DSPs are software-driven devices whose nature is sequential in executing algorithms, and hence have a significant effect on the bandwidth of the closed-loop control. To mitigate the said problem, the design of a Dedicated IFT Microcontroller is proposed in this thesis. To accomplish this goal, the preliminary task was to explore the IFT theory and its applications, followed by a review of the literature on FPGA design methodology for industrial control systems, Microcontroller design principles, and FPGA theory and trends. Furthermore, a survey of electronic design automation (EDA) tools and other application software was also conducted. After the literature review, the IFT was investigated exhaustively by applying it to three types of plants, namely: a DC motor, an oscillatory plant, and an unstable plant. Each of these plants were tested using three types of initial controllers, namely heavilydamped, critically damped and under-damped initial controllers. The plants were also tested by varying the amplitude of the reference signal, followed by using a single-step signal of constant amplitude of one volt. The intention of exploring all of these possibilities was meant to firmly expose the IFT boundaries of applicability, so that the final product would not be vulnerable to unnecessary post-production discoveries. The design methodology adopted in this research was a popular hierarchical and modular top-down procedure, which is an array of abstraction levels that are detailed as: system level, behavioural level, Register-Transfer Level (RTL) and Gate level. At system level, the Dedicated IFT Microcontroller was defined. Thereafter, at behavioural level, the design was simulated using VHDL, created by porting the LabView IFT code to the Xilinx EDA tool. At the RTL, the synthesisable VHDL code utilising fixed-point number representation was written. The compiled bit file was downloaded onto National Instruments (NI) Digital Electronics FPGA Board featuring iii the Spartan 3 series FPGA. This was tested, using a method known as simulation in the hardware. The key contribution of this thesis is the experimental validation of the IFT technique on FPGA hardware as it has never been published before, the work described in chapter four and five. The other contribution is the analysis of 1DOF IFT technique in terms of limitations of applicability for correct implementation, which is the main work of chapter three. This work could be used to explore other computational methods, like the use of floating-point number representation for high resolution and accuracy in numerical computations. Another avenue that could be exploited is Xilinx's recent Vivado methodology, which has the capacity for traditional programming languages like C or C++, as these have in-built floating-point number capability. Finally, out of this work, two papers have already been published by Springer and IEEE Xplore Publishers, and a journal paper has also been written for publication in the Control Systems Technology journal.
- Full Text:
- Date Issued: 2018
- Authors: Himunzowa, Grayson
- Date: 2018
- Subjects: Feedback control systems , Automatic control , Engineering design -- Data processing
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30017 , vital:30809
- Description: The design of a Dedicated IFT Microcontroller originated from the successful implementation of the Iterative Feedback Tuning (IFT) technique into the Digital Signal Processor microcontroller (DSP56F807C) at the University of Cape Town in 2006. However, implementation of the IFT technique on a general-purpose microcontroller is neither optimal, nor a cost-effective exercise, as most of the microcontroller peripherals remain unused, and drain energy for doing nothing. In addition, microcontrollers and DSPs are software-driven devices whose nature is sequential in executing algorithms, and hence have a significant effect on the bandwidth of the closed-loop control. To mitigate the said problem, the design of a Dedicated IFT Microcontroller is proposed in this thesis. To accomplish this goal, the preliminary task was to explore the IFT theory and its applications, followed by a review of the literature on FPGA design methodology for industrial control systems, Microcontroller design principles, and FPGA theory and trends. Furthermore, a survey of electronic design automation (EDA) tools and other application software was also conducted. After the literature review, the IFT was investigated exhaustively by applying it to three types of plants, namely: a DC motor, an oscillatory plant, and an unstable plant. Each of these plants were tested using three types of initial controllers, namely heavilydamped, critically damped and under-damped initial controllers. The plants were also tested by varying the amplitude of the reference signal, followed by using a single-step signal of constant amplitude of one volt. The intention of exploring all of these possibilities was meant to firmly expose the IFT boundaries of applicability, so that the final product would not be vulnerable to unnecessary post-production discoveries. The design methodology adopted in this research was a popular hierarchical and modular top-down procedure, which is an array of abstraction levels that are detailed as: system level, behavioural level, Register-Transfer Level (RTL) and Gate level. At system level, the Dedicated IFT Microcontroller was defined. Thereafter, at behavioural level, the design was simulated using VHDL, created by porting the LabView IFT code to the Xilinx EDA tool. At the RTL, the synthesisable VHDL code utilising fixed-point number representation was written. The compiled bit file was downloaded onto National Instruments (NI) Digital Electronics FPGA Board featuring iii the Spartan 3 series FPGA. This was tested, using a method known as simulation in the hardware. The key contribution of this thesis is the experimental validation of the IFT technique on FPGA hardware as it has never been published before, the work described in chapter four and five. The other contribution is the analysis of 1DOF IFT technique in terms of limitations of applicability for correct implementation, which is the main work of chapter three. This work could be used to explore other computational methods, like the use of floating-point number representation for high resolution and accuracy in numerical computations. Another avenue that could be exploited is Xilinx's recent Vivado methodology, which has the capacity for traditional programming languages like C or C++, as these have in-built floating-point number capability. Finally, out of this work, two papers have already been published by Springer and IEEE Xplore Publishers, and a journal paper has also been written for publication in the Control Systems Technology journal.
- Full Text:
- Date Issued: 2018
Detection of early warning signs of currency crises in South Africa
- Gondoza, Gladys Nicola Fernandes
- Authors: Gondoza, Gladys Nicola Fernandes
- Date: 2018
- Subjects: Financial crises -- 21st century
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/30238 , vital:30905
- Description: In a world characterised by globalisation, particularly increased financial integration and capital mobility, international economic theory stipulates that countries rather maintain a floating exchange rate system than a fixed exchange rate system in order to have less susceptibility to currency crises (Glick & Hutchison, 2011). South Africa, the economic powerhouse of Africa, is an interesting case to examine. It has a floating exchange rate and should thus be more resistant to currency crises due to market adjustment expectations that limit the build-up of pressure in its foreign exchange markets. South Africa’s foreign exchange market is characterised as volatile with recurring turbulent periods with currency crises observed in 1996, 1998, 2001 and 2008, of which the 2007/2008 global financial crisis was the worst the world had experienced since the Great Depression of the 1930s and it had a significant, negative impact on the South African economy and certainly exposed the country’s vulnerably (South African Reserve Bank, 2012). Having experienced these periods of currency crisis in South Africa and with no specific tool adequately tested and developed for the South African economy to accurately detect such an event before its occurrence, this research was an attempt to fill this gap within the economics discipline. The purpose of this thesis was to examine and make use of Early Warning System (EWS) models to ascertain which one best identifies potential early warning signs of a currency crisis in South Africa. To achieve this, the study tested two standard and commonly used EWS models, namely the Signals and probit models. Added to these approaches, two newer EWS models, namely the Markov regime switching model and the artificial neural networks model were tested. To date only two studies on EWS models for currency crises have been conducted in South Africa. Knedlik (2006) used the signals approach and Knedlik and Scheufele (2007) used the signals, probit/logit and Markov regime switching approaches. Both studies recommended that further research was needed. With this in mind, this thesis built on these studies by extending the sample period under observation from 1993/02 to 2017/03 to fully capture the probability of the global financial crisis of 2007/2008. This study separated the sample period into two parts, a first period (1993/02 – 2004/12) catering for the July 1998 and December 2001 crises and a second period (2005/01 – 2017/03) catering for the October 2008 crisis. This was done to separately observe how well the models detected early warning signs of the October 2008 crisis due to its global nature. By exploring the potential of artificial intelligence by employing the non-parametric approach of artificial neural networks, which has not yet been applied in the South African context for the probability prediction of currency crises, and comparing its prediction performance to the signals, the probit and the Markov regime switching EWS models, this thesis fills an existing information gap. This study found that of these four EWS models for predicting the probabilities of currency crises within the 24-month crisis window, the signals model performed better than the other models for the period 1993/02 – 2004/12. However, the final-outcome of the best model in probability prediction of South African currency crises is not straightforward for this period, as the artificial neural network model and Markov regime switching model performed almost as well as the signals model. During the period 2005/01 – 2017/03, the artificial neural networks model outperformed the other three models in capturing the global financial crisis of 2007/2008, specifically with regard to the evaluations of the percentage of pre-crisis periods called correctly and the percentage of tranquil periods called correctly. As the cut-off probability increases, the artificial neural networks model is the superior model and is not closely followed by the other models. The artificial neural network model also indicated a stable / tranquil economy during the period following the global financial crisis (from about 2009 – 2017), which is a true reflection of that period. The findings of this study suggest that the artificial neural network model is a powerful tool in the probability prediction of early warning signs of currency crises in South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Gondoza, Gladys Nicola Fernandes
- Date: 2018
- Subjects: Financial crises -- 21st century
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/30238 , vital:30905
- Description: In a world characterised by globalisation, particularly increased financial integration and capital mobility, international economic theory stipulates that countries rather maintain a floating exchange rate system than a fixed exchange rate system in order to have less susceptibility to currency crises (Glick & Hutchison, 2011). South Africa, the economic powerhouse of Africa, is an interesting case to examine. It has a floating exchange rate and should thus be more resistant to currency crises due to market adjustment expectations that limit the build-up of pressure in its foreign exchange markets. South Africa’s foreign exchange market is characterised as volatile with recurring turbulent periods with currency crises observed in 1996, 1998, 2001 and 2008, of which the 2007/2008 global financial crisis was the worst the world had experienced since the Great Depression of the 1930s and it had a significant, negative impact on the South African economy and certainly exposed the country’s vulnerably (South African Reserve Bank, 2012). Having experienced these periods of currency crisis in South Africa and with no specific tool adequately tested and developed for the South African economy to accurately detect such an event before its occurrence, this research was an attempt to fill this gap within the economics discipline. The purpose of this thesis was to examine and make use of Early Warning System (EWS) models to ascertain which one best identifies potential early warning signs of a currency crisis in South Africa. To achieve this, the study tested two standard and commonly used EWS models, namely the Signals and probit models. Added to these approaches, two newer EWS models, namely the Markov regime switching model and the artificial neural networks model were tested. To date only two studies on EWS models for currency crises have been conducted in South Africa. Knedlik (2006) used the signals approach and Knedlik and Scheufele (2007) used the signals, probit/logit and Markov regime switching approaches. Both studies recommended that further research was needed. With this in mind, this thesis built on these studies by extending the sample period under observation from 1993/02 to 2017/03 to fully capture the probability of the global financial crisis of 2007/2008. This study separated the sample period into two parts, a first period (1993/02 – 2004/12) catering for the July 1998 and December 2001 crises and a second period (2005/01 – 2017/03) catering for the October 2008 crisis. This was done to separately observe how well the models detected early warning signs of the October 2008 crisis due to its global nature. By exploring the potential of artificial intelligence by employing the non-parametric approach of artificial neural networks, which has not yet been applied in the South African context for the probability prediction of currency crises, and comparing its prediction performance to the signals, the probit and the Markov regime switching EWS models, this thesis fills an existing information gap. This study found that of these four EWS models for predicting the probabilities of currency crises within the 24-month crisis window, the signals model performed better than the other models for the period 1993/02 – 2004/12. However, the final-outcome of the best model in probability prediction of South African currency crises is not straightforward for this period, as the artificial neural network model and Markov regime switching model performed almost as well as the signals model. During the period 2005/01 – 2017/03, the artificial neural networks model outperformed the other three models in capturing the global financial crisis of 2007/2008, specifically with regard to the evaluations of the percentage of pre-crisis periods called correctly and the percentage of tranquil periods called correctly. As the cut-off probability increases, the artificial neural networks model is the superior model and is not closely followed by the other models. The artificial neural network model also indicated a stable / tranquil economy during the period following the global financial crisis (from about 2009 – 2017), which is a true reflection of that period. The findings of this study suggest that the artificial neural network model is a powerful tool in the probability prediction of early warning signs of currency crises in South Africa.
- Full Text:
- Date Issued: 2018
Determinants of Type 2 diabetes mellitus among HIV/AIDS patients on antiretroviral drugs in the OR Tambo District, South Africa
- Authors: Bam, Nokwanda Edith
- Date: 2018
- Subjects: HIV/AIDS Diabetes mellitus (DM) -- Patients Antiretroviral drugs -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD Health Sciences
- Identifier: http://hdl.handle.net/11260/1476 , vital:35976
- Description: Type 2 diabetes mellitus (DM) is a frequent adverse effect of antiretroviral drugs for those who are on ARVS. People with type 2 DM can suffer multiple complications that hinder the quality of life. In South Africa research has shown significant increase in neuropathy, heart and kidney diseases among patients living with type 2 DM and HIV/AIDS compared to DM without HIV. Accessed knowledge lacked consistency on the predictors of DM in HIV/AIDS patients with regards to the type of ARVS with higher risks of DM. Research needed to be done to find the determinants of type 2 DM in HIV/AIDS context. The purpose of this study was to describe the determinants of type 2 DM among HIV/AIDS patients on ARVS in the OR Tambo District, SA in order to develop intervention strategies to mitigate the long-term effects of type 2 DM. A quantitative research methodology using a case control retrospective study was used. A sample of 177 (33%) cases with HIV/AIDS and type 2 DM was selected using a one stage stratified sampling with allocation proportional to size of each stratum of the four sub-districts of OR Tambo District. Two non-diabetic patients with HIV/AIDS were selected as controls per case unpaired and totalled up to 354 (67%) controls. A self-administration questionnaire adopted from the WHO (2011) STEPwise surveillance tool for chronic diseases was used for data collection. Stata (standard version 13.0, Stata Corp., Lakeway Drive USA) was used for data management and analysis. Findings of the study revealed determinants of type 2 DM grouped as the socio-demographic determinants; tertiary education and marital status, levels of physical activities; lack of vigorous activity and sport, types of diets; high fruits and vegetables and healthy eating out at restaurants, arterial blood pressure; lack of routine BP check and known HPT and types of ARVS used in HIV/AIDS therapy. Compared with patients who received FDC, the risk of type 2 DM was 43 times and 22 higher when a tri-therapy regimen contained Ritonavir and Lopinavir respectively . The majority of DM patients (n=177) were diagnosed type 2 DM after ARVS at n=108 (61%). In managing the diabetic patients a shift from a single disease to multiple-chronic disease focus is required to mitigate the complex drug interactions that exist in the control of NCDs such as HIV/AIDS, DM, HPT and other long-term diseases. The HIV/AIDS and type 2 DM awareness and care intervention strategy is recommended as healthy lifestyle, monitoring of side effects and drug interactions, enhanced FDC roll out and elimination of unsafe ARVS to improve the health outcomes of type 2 DM patients in an HIV/AIDS context in OR Tambo District.
- Full Text:
- Date Issued: 2018
- Authors: Bam, Nokwanda Edith
- Date: 2018
- Subjects: HIV/AIDS Diabetes mellitus (DM) -- Patients Antiretroviral drugs -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD Health Sciences
- Identifier: http://hdl.handle.net/11260/1476 , vital:35976
- Description: Type 2 diabetes mellitus (DM) is a frequent adverse effect of antiretroviral drugs for those who are on ARVS. People with type 2 DM can suffer multiple complications that hinder the quality of life. In South Africa research has shown significant increase in neuropathy, heart and kidney diseases among patients living with type 2 DM and HIV/AIDS compared to DM without HIV. Accessed knowledge lacked consistency on the predictors of DM in HIV/AIDS patients with regards to the type of ARVS with higher risks of DM. Research needed to be done to find the determinants of type 2 DM in HIV/AIDS context. The purpose of this study was to describe the determinants of type 2 DM among HIV/AIDS patients on ARVS in the OR Tambo District, SA in order to develop intervention strategies to mitigate the long-term effects of type 2 DM. A quantitative research methodology using a case control retrospective study was used. A sample of 177 (33%) cases with HIV/AIDS and type 2 DM was selected using a one stage stratified sampling with allocation proportional to size of each stratum of the four sub-districts of OR Tambo District. Two non-diabetic patients with HIV/AIDS were selected as controls per case unpaired and totalled up to 354 (67%) controls. A self-administration questionnaire adopted from the WHO (2011) STEPwise surveillance tool for chronic diseases was used for data collection. Stata (standard version 13.0, Stata Corp., Lakeway Drive USA) was used for data management and analysis. Findings of the study revealed determinants of type 2 DM grouped as the socio-demographic determinants; tertiary education and marital status, levels of physical activities; lack of vigorous activity and sport, types of diets; high fruits and vegetables and healthy eating out at restaurants, arterial blood pressure; lack of routine BP check and known HPT and types of ARVS used in HIV/AIDS therapy. Compared with patients who received FDC, the risk of type 2 DM was 43 times and 22 higher when a tri-therapy regimen contained Ritonavir and Lopinavir respectively . The majority of DM patients (n=177) were diagnosed type 2 DM after ARVS at n=108 (61%). In managing the diabetic patients a shift from a single disease to multiple-chronic disease focus is required to mitigate the complex drug interactions that exist in the control of NCDs such as HIV/AIDS, DM, HPT and other long-term diseases. The HIV/AIDS and type 2 DM awareness and care intervention strategy is recommended as healthy lifestyle, monitoring of side effects and drug interactions, enhanced FDC roll out and elimination of unsafe ARVS to improve the health outcomes of type 2 DM patients in an HIV/AIDS context in OR Tambo District.
- Full Text:
- Date Issued: 2018