Yeast-baculovirus synergism: investigating mixed infections for improved management of the false codling moth, Thaumatotibia leucotreta
- Authors: Van der Merwe, Marcel
- Date: 2018
- Subjects: Cryptophlebia leucotreta , Baculoviruses , Yeast , Citrus Diseases and pests , Biological pest control agents , Pests Integrated control
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/62963 , vital:28347
- Description: Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) or otherwise commonly known as the false codling moth is an indigenous pest of the citrus industry in southern Africa. The pest is highly significant as it impacts negatively on the export of fresh citrus fruits from South Africa to international markets. To control T. leucotreta in South Africa, an integrated pest management (IPM) programme has been implemented. One component of this programme is the baculovirus Cryptophlebia leucotreta granulovirus (CrleGV-SA) which has been formulated into the products Cryptogran™ and Cryptex®. It has previously been reported that there is a mutualistic association between Cydia pomonella (L.) (Lepidoptera: Tortricidae) also known as codling moth, and epiphytic yeasts. Cydia pomonella larval feeding galleries were colonised by yeasts and this, in turn, reduced larval mortality and enhanced larval development. It has been demonstrated in laboratory assays and field trials that combining yeast and brown cane sugar with Cydia pomonella granulovirus (CpGV) significantly increased larval mortality and lowered the proportion of injured apple fruit. This suggests that yeasts can enhance the effectiveness of an insect virus in managing pest larvae. In this study, we proposed to determine which species of yeast occur naturally in the digestive tract, frass and on the epidermis of T. leucotreta larvae and to examine whether any of these yeasts, when combined with the CrleGV-SA, have a synergistic effect in increasing mortality of T. leucotreta larvae. Firstly, Navel oranges infested with T. leucotreta larvae were collected from orchards in Sundays River Valley in Eastern Cape of South Africa. Larvae were extracted and analysed for the presence of yeast on their surface, or in their gut and frass. Four yeasts were isolated from T. leucotreta larvae and identified down to species level via PCR amplification and sequencing of internal transcribed spacer (ITS) region and D1/D2 domain of the large subunit (LSU) of rDNA region. These yeasts were isolated from the frass, epidermis and digestive tract of T. leucotreta larvae. The yeast isolates were identified as Meyerozyma caribbica, Pichia kluyveri, Pichia kudriavzevii and Hanseniaspora opuntiae. A yeast preference assay was conducted on female T. leucotreta moths to examine whether any of the isolated yeast species affected their oviposition preference. Navel oranges were inoculated with the isolated yeast species at a concentration of 6 × 108 cells.ml-1. The assay also included a Brewer’s yeast and distilled water control. Pichia kudriavzevii was shown to be the preferred yeast species for oviposition, as significantly more eggs were deposited on Navel oranges inoculated with this yeast compared to the other treatments. Lastly, a detached fruit bioassay was performed to evaluate the efficacy of mixing P. kudriavzevii with CrleGV-SA to enhance T. leucotreta larvae mortality. Pichia kudriavzevii was selected as it was demonstrated as having an effect on the oviposition preference of female T. leucotreta moths. The concentration at which P. kudriavzevii was applied remained the same as in the preference assay while CrleGV-SA was applied at lethal concentration required to kill 50 % of the population (9.31 × 107 OBs.ml-1). Although an increase in larval mortality was observed between CrleGV-SA being applied alone and the yeast/virus mixture, this result was determined not to be statistically significant. The experiments performed in this study provide a platform for further research into the application of a yeast-virus combination as a novel control option for T. leucotreta in the field. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2018
- Authors: Van der Merwe, Marcel
- Date: 2018
- Subjects: Cryptophlebia leucotreta , Baculoviruses , Yeast , Citrus Diseases and pests , Biological pest control agents , Pests Integrated control
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/62963 , vital:28347
- Description: Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) or otherwise commonly known as the false codling moth is an indigenous pest of the citrus industry in southern Africa. The pest is highly significant as it impacts negatively on the export of fresh citrus fruits from South Africa to international markets. To control T. leucotreta in South Africa, an integrated pest management (IPM) programme has been implemented. One component of this programme is the baculovirus Cryptophlebia leucotreta granulovirus (CrleGV-SA) which has been formulated into the products Cryptogran™ and Cryptex®. It has previously been reported that there is a mutualistic association between Cydia pomonella (L.) (Lepidoptera: Tortricidae) also known as codling moth, and epiphytic yeasts. Cydia pomonella larval feeding galleries were colonised by yeasts and this, in turn, reduced larval mortality and enhanced larval development. It has been demonstrated in laboratory assays and field trials that combining yeast and brown cane sugar with Cydia pomonella granulovirus (CpGV) significantly increased larval mortality and lowered the proportion of injured apple fruit. This suggests that yeasts can enhance the effectiveness of an insect virus in managing pest larvae. In this study, we proposed to determine which species of yeast occur naturally in the digestive tract, frass and on the epidermis of T. leucotreta larvae and to examine whether any of these yeasts, when combined with the CrleGV-SA, have a synergistic effect in increasing mortality of T. leucotreta larvae. Firstly, Navel oranges infested with T. leucotreta larvae were collected from orchards in Sundays River Valley in Eastern Cape of South Africa. Larvae were extracted and analysed for the presence of yeast on their surface, or in their gut and frass. Four yeasts were isolated from T. leucotreta larvae and identified down to species level via PCR amplification and sequencing of internal transcribed spacer (ITS) region and D1/D2 domain of the large subunit (LSU) of rDNA region. These yeasts were isolated from the frass, epidermis and digestive tract of T. leucotreta larvae. The yeast isolates were identified as Meyerozyma caribbica, Pichia kluyveri, Pichia kudriavzevii and Hanseniaspora opuntiae. A yeast preference assay was conducted on female T. leucotreta moths to examine whether any of the isolated yeast species affected their oviposition preference. Navel oranges were inoculated with the isolated yeast species at a concentration of 6 × 108 cells.ml-1. The assay also included a Brewer’s yeast and distilled water control. Pichia kudriavzevii was shown to be the preferred yeast species for oviposition, as significantly more eggs were deposited on Navel oranges inoculated with this yeast compared to the other treatments. Lastly, a detached fruit bioassay was performed to evaluate the efficacy of mixing P. kudriavzevii with CrleGV-SA to enhance T. leucotreta larvae mortality. Pichia kudriavzevii was selected as it was demonstrated as having an effect on the oviposition preference of female T. leucotreta moths. The concentration at which P. kudriavzevii was applied remained the same as in the preference assay while CrleGV-SA was applied at lethal concentration required to kill 50 % of the population (9.31 × 107 OBs.ml-1). Although an increase in larval mortality was observed between CrleGV-SA being applied alone and the yeast/virus mixture, this result was determined not to be statistically significant. The experiments performed in this study provide a platform for further research into the application of a yeast-virus combination as a novel control option for T. leucotreta in the field. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2018
The implementation of a push-pull programme for the control of Eldana saccharina (Lepidoptera: Pyralidae) in sugarcane in the coastal regions of Kwazulu-Natal, South Africa
- Authors: Mulcahy, Megan Marie
- Date: 2018
- Subjects: Pyralidae -- South Africa -- KwaZulu-Natal , Pests -- Integrated control , Sugarcane -- Diseases and pests -- South Africa -- KwaZulu-Natal , Stem borers -- Effect of habitat modification on -- South Africa -- KwaZulu-Natal , Insect-plant relationships -- South Africa -- KwaZulu-Natal
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63290 , vital:28390
- Description: Eldana saccharina, an indigenous lepidopteran stemborer, is considered the most damaging pest of sugarcane in South Africa. Researchers have advocated the use of an area-wide integrated pest management (AW-IPM) programme as a means of improving the control of this pest. A push-pull strategy was developed as a component of this AW-IPM approach. The push-pull strategy in sugarcane is a habitat management method of pest control that uses plants that are both repellent (Melinis Minutiflora) and attractive (Cyperus dives, Cyperus papyrus and Bt-maize) to E. saccharina. Previous research into push-pull has shown that this strategy is an effective tool for the control of E. saccharina. Push-pull has been implemented successfully in the Midlands North sugarcane growing region of KwaZulu-Natal (KZN), South Africa. Despite the proven efficacy of push-pull, very little push-pull research has been conducted in the coastal sugarcane growing regions of KZN, and adoption of this technology has been poor in these regions. Therefore, the aim of this research was to facilitate the implementation of push-pull for the management of E. saccharina in sugarcane in the coastal regions of KZN. This was done by focussing on on-farm field trials and farmer participatory research. On-farm push-pull field trials were conducted on five model farms in the North and South Coast sugarcane growing regions of KZN. High levels of E. saccharina were recorded during this study. The push-pull treatment sites showed a significant reduction of E. saccharina damage on four of the five farms used in the study. Mean percentage of stalks damaged decreased by up to 50 % in the presence of the repellent grass species, M. minutiflora. The number of E. saccharina found per 100 stalks also decreased significantly at these farms. The farm which did not show a significant reduction in E. saccharina populations or damage had low numbers of this pest in the sugarcane throughout the experiment. This demonstrates that push-pull is more effective in areas that have high levels of E. saccharina. Stem borer surveys in wetlands on sugarcane farms revealed that high numbers of E. saccharina were found within the pull plants, C. papyrus and C. dives, in comparison to the push-pull sites. This verifies that the pull plants do work efficiently to attract E. saccharina away from sugarcane. Additionally, eight parasitoids emerged from E. saccharina larvae collected in wetland sedges. The beneficial roles that push-pull plants play in attracting and maintaining natural enemies in the agroecosystem are discussed, and these findings further demonstrate the important ecosystem, and pest management services that wetlands provide on sugarcane farms. The success of the push-pull trials in this study show that this technology can be an effective tool for controlling E. saccharina in the coastal sugarcane growing regions. The timing of the planting of push-pull plants was shown to play a role in the efficacy of this technology. The study also confirmed that push-pull should be used as a component of AW-IPM in conjunction with good crop management practices. Surveys were undertaken to determine large-scale sugarcane growers' (LSGs) knowledge and perceptions of E. saccharina and other pests. Research regarding the farmers' perceptions of push- pull was also conducted to better understand the drivers and barriers to adoption of push-pull, and other new technologies. The surveys found that large-scale farmers in the coastal regions suffer from high infestations of E. saccharina. As such there is scope for the introduction of new pest management practices such as push-pull in this area. Farmers also demonstrated a good basic knowledge of E. saccharina and IPM. However, LSGs had a poor understanding of push-pull and how it works, as well as the plants that make up the push-pull system that is being implemented against E. saccharina in South Africa. A dearth in practical knowledge regarding the implementation of push-pull was seen as a major barrier to the adoption of this strategy, as was financial instability, farmer attitudes and poor institutional support. Farmers recommended collaboration amongst stakeholders, improved education, proof of the efficacy of push-pull and incentives as tools to improve the implementation of this strategy in the coastal sugarcane growing regions of KZN. Farmers preferred direct contact with extension personnel and experiential learning opportunities when acquiring information about push- pull and other new pest management practices. If opportunities for push-pull education are increased through direct contact with extension personnel, and through on-farm demonstrations, and if inputs are provided in the form of push-pull plants, it is likely that push-pull will succeed amongst coastal LSGs, especially since farmers had an overall positive attitude towards the technology. Surveys amongst small-scale sugarcane growers (SSGs) showed that sugarcane is important in the lives of these farmers. The SSGs perceive pests to be a major constraint to their farming systems, and they identified E. saccharina as a major pest of sugarcane. The farmers also demonstrated good knowledge of sugarcane pests and vegetable pests. However, SSGs lacked knowledge regarding pest management practices and beneficial insects. Extension and advisory services should to continue concentrating on pest management practices to educate SSGs on the variety and application of pest control strategies. SSGs were found to employ complex, diverse and integrated agricultural systems that are well-suited to the implementation of IPM technologies such as push-pull. Since insect pests act were found to be a major constraint to SSG sugarcane production, push-pull was deemed a feasible pest management strategy for coastal farmers and its implementation by SSGs should be further explored. SSGs in this study were also concerned about vegetable pests, therefore if push-pull can be adapted to help protect additional crops, adoption of this technology by small-scale growers will improve.
- Full Text:
- Date Issued: 2018
- Authors: Mulcahy, Megan Marie
- Date: 2018
- Subjects: Pyralidae -- South Africa -- KwaZulu-Natal , Pests -- Integrated control , Sugarcane -- Diseases and pests -- South Africa -- KwaZulu-Natal , Stem borers -- Effect of habitat modification on -- South Africa -- KwaZulu-Natal , Insect-plant relationships -- South Africa -- KwaZulu-Natal
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63290 , vital:28390
- Description: Eldana saccharina, an indigenous lepidopteran stemborer, is considered the most damaging pest of sugarcane in South Africa. Researchers have advocated the use of an area-wide integrated pest management (AW-IPM) programme as a means of improving the control of this pest. A push-pull strategy was developed as a component of this AW-IPM approach. The push-pull strategy in sugarcane is a habitat management method of pest control that uses plants that are both repellent (Melinis Minutiflora) and attractive (Cyperus dives, Cyperus papyrus and Bt-maize) to E. saccharina. Previous research into push-pull has shown that this strategy is an effective tool for the control of E. saccharina. Push-pull has been implemented successfully in the Midlands North sugarcane growing region of KwaZulu-Natal (KZN), South Africa. Despite the proven efficacy of push-pull, very little push-pull research has been conducted in the coastal sugarcane growing regions of KZN, and adoption of this technology has been poor in these regions. Therefore, the aim of this research was to facilitate the implementation of push-pull for the management of E. saccharina in sugarcane in the coastal regions of KZN. This was done by focussing on on-farm field trials and farmer participatory research. On-farm push-pull field trials were conducted on five model farms in the North and South Coast sugarcane growing regions of KZN. High levels of E. saccharina were recorded during this study. The push-pull treatment sites showed a significant reduction of E. saccharina damage on four of the five farms used in the study. Mean percentage of stalks damaged decreased by up to 50 % in the presence of the repellent grass species, M. minutiflora. The number of E. saccharina found per 100 stalks also decreased significantly at these farms. The farm which did not show a significant reduction in E. saccharina populations or damage had low numbers of this pest in the sugarcane throughout the experiment. This demonstrates that push-pull is more effective in areas that have high levels of E. saccharina. Stem borer surveys in wetlands on sugarcane farms revealed that high numbers of E. saccharina were found within the pull plants, C. papyrus and C. dives, in comparison to the push-pull sites. This verifies that the pull plants do work efficiently to attract E. saccharina away from sugarcane. Additionally, eight parasitoids emerged from E. saccharina larvae collected in wetland sedges. The beneficial roles that push-pull plants play in attracting and maintaining natural enemies in the agroecosystem are discussed, and these findings further demonstrate the important ecosystem, and pest management services that wetlands provide on sugarcane farms. The success of the push-pull trials in this study show that this technology can be an effective tool for controlling E. saccharina in the coastal sugarcane growing regions. The timing of the planting of push-pull plants was shown to play a role in the efficacy of this technology. The study also confirmed that push-pull should be used as a component of AW-IPM in conjunction with good crop management practices. Surveys were undertaken to determine large-scale sugarcane growers' (LSGs) knowledge and perceptions of E. saccharina and other pests. Research regarding the farmers' perceptions of push- pull was also conducted to better understand the drivers and barriers to adoption of push-pull, and other new technologies. The surveys found that large-scale farmers in the coastal regions suffer from high infestations of E. saccharina. As such there is scope for the introduction of new pest management practices such as push-pull in this area. Farmers also demonstrated a good basic knowledge of E. saccharina and IPM. However, LSGs had a poor understanding of push-pull and how it works, as well as the plants that make up the push-pull system that is being implemented against E. saccharina in South Africa. A dearth in practical knowledge regarding the implementation of push-pull was seen as a major barrier to the adoption of this strategy, as was financial instability, farmer attitudes and poor institutional support. Farmers recommended collaboration amongst stakeholders, improved education, proof of the efficacy of push-pull and incentives as tools to improve the implementation of this strategy in the coastal sugarcane growing regions of KZN. Farmers preferred direct contact with extension personnel and experiential learning opportunities when acquiring information about push- pull and other new pest management practices. If opportunities for push-pull education are increased through direct contact with extension personnel, and through on-farm demonstrations, and if inputs are provided in the form of push-pull plants, it is likely that push-pull will succeed amongst coastal LSGs, especially since farmers had an overall positive attitude towards the technology. Surveys amongst small-scale sugarcane growers (SSGs) showed that sugarcane is important in the lives of these farmers. The SSGs perceive pests to be a major constraint to their farming systems, and they identified E. saccharina as a major pest of sugarcane. The farmers also demonstrated good knowledge of sugarcane pests and vegetable pests. However, SSGs lacked knowledge regarding pest management practices and beneficial insects. Extension and advisory services should to continue concentrating on pest management practices to educate SSGs on the variety and application of pest control strategies. SSGs were found to employ complex, diverse and integrated agricultural systems that are well-suited to the implementation of IPM technologies such as push-pull. Since insect pests act were found to be a major constraint to SSG sugarcane production, push-pull was deemed a feasible pest management strategy for coastal farmers and its implementation by SSGs should be further explored. SSGs in this study were also concerned about vegetable pests, therefore if push-pull can be adapted to help protect additional crops, adoption of this technology by small-scale growers will improve.
- Full Text:
- Date Issued: 2018
Stories in watercolour
- Authors: Molefhe, Wame Miriam
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63552 , vital:28436
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
- Authors: Molefhe, Wame Miriam
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63552 , vital:28436
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
The fourth industrial revolution and human capital development
- Authors: Goldschmidt, Kyle
- Date: 2018
- Subjects: Technological innovations -- Economic aspects , Human capital , Intellectual capital , Economic development , Economic development -- Effect of education on , Fourth industrial revolution
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/62483 , vital:28197
- Description: The focus of the Fourth Industrial Revolution has been on its implications on Human Capital and its need to develop “21st-Century Skills" through education to ensure future labour and capital complementarity. Human Capital combined with 21st-Century Skills, it is claimed, can together generate economic growth, jobs and propel an economy into the next Industrial Revolution. However, Schwab’s (2016) concept of the Fourth Industrial Revolution, make no distinction between the Average Worker and the Knowledge Elite and their relationship to each other and successful economic growth. The different nature of these skills is absent in the literature to date. A critical analysis of literature will be used to examine Schwab’s (2016) claim of a Fourth Industrial Revolution and assess how the Average Worker and the Knowledge Elite relate to the Fourth Industrial Revolution and 21st-Century Skills. The evidence is provided on how both the Average Worker and the Knowledge Elite are key contributors to economic growth and will be important in the Fourth Industrial Revolution.
- Full Text:
- Date Issued: 2018
- Authors: Goldschmidt, Kyle
- Date: 2018
- Subjects: Technological innovations -- Economic aspects , Human capital , Intellectual capital , Economic development , Economic development -- Effect of education on , Fourth industrial revolution
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/62483 , vital:28197
- Description: The focus of the Fourth Industrial Revolution has been on its implications on Human Capital and its need to develop “21st-Century Skills" through education to ensure future labour and capital complementarity. Human Capital combined with 21st-Century Skills, it is claimed, can together generate economic growth, jobs and propel an economy into the next Industrial Revolution. However, Schwab’s (2016) concept of the Fourth Industrial Revolution, make no distinction between the Average Worker and the Knowledge Elite and their relationship to each other and successful economic growth. The different nature of these skills is absent in the literature to date. A critical analysis of literature will be used to examine Schwab’s (2016) claim of a Fourth Industrial Revolution and assess how the Average Worker and the Knowledge Elite relate to the Fourth Industrial Revolution and 21st-Century Skills. The evidence is provided on how both the Average Worker and the Knowledge Elite are key contributors to economic growth and will be important in the Fourth Industrial Revolution.
- Full Text:
- Date Issued: 2018
A counter-narrative analysis of psychological riot in contemporary painting
- Authors: Ng’ok, Ivy Chemutai
- Date: 2018
- Subjects: Painting -- South Africa , Painting -- Psychological aspects , Distress (Psychology) in art , Imperialism in art , Violence in art , Patriarchy in art Political art
- Language: English
- Type: text , Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/60458 , vital:27782
- Description: I am rioting against a system of my own beliefs about the world. In my mind, I struggle to overcome these beliefs, hence, I construct the psychological riot as ‘the disturbance of the mind’. In this mini-thesis, I argue that it exists in the psyche too. This definition of psyche becomes painterly. My psychological riot is difficult to trace, let alone paint. The beliefs that I target are patriarchy within a post-colonial context. I use theories that are simultaneously psychological and corporeal. They address violence colonialist system. The psychological riot is an practical submission.
- Full Text:
- Date Issued: 2018
- Authors: Ng’ok, Ivy Chemutai
- Date: 2018
- Subjects: Painting -- South Africa , Painting -- Psychological aspects , Distress (Psychology) in art , Imperialism in art , Violence in art , Patriarchy in art Political art
- Language: English
- Type: text , Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/60458 , vital:27782
- Description: I am rioting against a system of my own beliefs about the world. In my mind, I struggle to overcome these beliefs, hence, I construct the psychological riot as ‘the disturbance of the mind’. In this mini-thesis, I argue that it exists in the psyche too. This definition of psyche becomes painterly. My psychological riot is difficult to trace, let alone paint. The beliefs that I target are patriarchy within a post-colonial context. I use theories that are simultaneously psychological and corporeal. They address violence colonialist system. The psychological riot is an practical submission.
- Full Text:
- Date Issued: 2018
The role of ecological processes in structuring reef fish communities in the Agulhas Ecoregion, South Africa
- Authors: Dyer, Alexander
- Date: 2018
- Subjects: Reef fishes -- South Africa -- Agulhas, Cape (Cape) , Reef fishes -- Ecology -- South Africa -- Agulhas, Cape (Cape) , Marine biodiversity -- South Africa -- Agulhas, Cape (Cape) , Biotic communities -- South Africa -- Agulhas, Cape (Cape) , Sparidae -- South Africa -- Agulhas, Cape (Cape) , Reef fishes -- Size -- South Africa -- Agulhas, Cape (Cape) , Baited remote underwater stereo-video systems (stereo-BRUVs)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63899 , vital:28504
- Description: Local, niche-based processes, which arise from the interplay between biotic interactions and abiotic constraints are considered to be important regulators of community structure. However, it is increasingly recognised that patterns of diversity can also be strongly influenced by dispersal-driven processes. While empirical research on the diversity of coral reef fishes on shallow tropical reefs has contributed greatly to the development of general concepts in ecology, there have been considerably fewer studies on the processes which shape the diversity of fish communities on shallow (10 - 30 m) and deep (30 - 75 m) rocky reefs. Consequently, it is less clear at which spatial scales niche partitioning and dispersal limitation contribute most strongly to the structure of reef-associated fish communities within rocky reef ecosystems. To address this caveat, research was conducted at four rocky reef complexes within the warm-temperate Agulhas Ecoregion, South Africa. The diversity of reef-associated fishes was sampled by baited remote underwater stereo-video systems (stereo-BRUVs) to incorporate the range of heterogeneous reef habitat in Tsitsikamma National Park Marine Protected Area (TNP MPA) and Algoa Bay (AB). To examine how niche-based and dispersal-driven processes influence patterns of diversity among species within the dominant family of resident fishes, the sparids (Sparidae), components of diversity were quantified at several spatial scales. Turnover in the number of species which locally co-occurred was found to be largely driven by the limited dispersal of species over hundreds of kilometres. When relative species abundances were taken into account, sparid communities were characterised by higher than expected rates of compositional turnover among local habitat patches separated by hundreds to thousands of metres of contiguous reef. Patterns of compositional turnover were associated with the spatial aggregation of conspecifics, particularly at scales which facilitate the post-settlement dispersal of fishes. Niche-based segregation of species along the depth gradient was found to be the primary driver of compositional turnover among both protected and exploited communities. However, spatial structuring within reefs, which was independent of variation in the environment, suggests that compositional differences among communities are also influenced by the limited post-settlement dispersal of resident fishes to adjacent areas during their ontogeny. Together, the results suggest that the diversity of reef-associated sparids is likely to depend both on an adequate diversity of suitable reef habitat and a sufficient degree of spatial connectivity to facilitate ontogenetic habitat shifts. Taxon-based descriptors of diversity do not adequately account for ecological difference among conspecifics within size-structured populations. To test whether differences in body size facilitated coexistence among sparid fishes, the number of species which coexisted at the local scale was related to variation in the size structure of communities. In communities which have been historically protected from fishing, local coexistence between a greater number of species was promoted by reduced levels of intraspecific variation in size of fishes. This suggests that, among species with similar trophic requirements, further niche segregation along a prey-size and body-size gradient is likely to mitigate the direct impacts of competition for shared food resources. Among exploited communities, size structure did not influence the number of species which coexisted at the local scale. This finding suggests that fishing-induced mortality of larger-bodied fishes is likely to remove some of the constraints to colonisation which arise from asymmetries in competitive fitness between small and large-bodied fishes. Together, these results highlight the importance of post-settlement processes and population size structure to the maintenance of reef-associated fish diversity within contiguous rocky reef habitats.
- Full Text:
- Date Issued: 2018
- Authors: Dyer, Alexander
- Date: 2018
- Subjects: Reef fishes -- South Africa -- Agulhas, Cape (Cape) , Reef fishes -- Ecology -- South Africa -- Agulhas, Cape (Cape) , Marine biodiversity -- South Africa -- Agulhas, Cape (Cape) , Biotic communities -- South Africa -- Agulhas, Cape (Cape) , Sparidae -- South Africa -- Agulhas, Cape (Cape) , Reef fishes -- Size -- South Africa -- Agulhas, Cape (Cape) , Baited remote underwater stereo-video systems (stereo-BRUVs)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63899 , vital:28504
- Description: Local, niche-based processes, which arise from the interplay between biotic interactions and abiotic constraints are considered to be important regulators of community structure. However, it is increasingly recognised that patterns of diversity can also be strongly influenced by dispersal-driven processes. While empirical research on the diversity of coral reef fishes on shallow tropical reefs has contributed greatly to the development of general concepts in ecology, there have been considerably fewer studies on the processes which shape the diversity of fish communities on shallow (10 - 30 m) and deep (30 - 75 m) rocky reefs. Consequently, it is less clear at which spatial scales niche partitioning and dispersal limitation contribute most strongly to the structure of reef-associated fish communities within rocky reef ecosystems. To address this caveat, research was conducted at four rocky reef complexes within the warm-temperate Agulhas Ecoregion, South Africa. The diversity of reef-associated fishes was sampled by baited remote underwater stereo-video systems (stereo-BRUVs) to incorporate the range of heterogeneous reef habitat in Tsitsikamma National Park Marine Protected Area (TNP MPA) and Algoa Bay (AB). To examine how niche-based and dispersal-driven processes influence patterns of diversity among species within the dominant family of resident fishes, the sparids (Sparidae), components of diversity were quantified at several spatial scales. Turnover in the number of species which locally co-occurred was found to be largely driven by the limited dispersal of species over hundreds of kilometres. When relative species abundances were taken into account, sparid communities were characterised by higher than expected rates of compositional turnover among local habitat patches separated by hundreds to thousands of metres of contiguous reef. Patterns of compositional turnover were associated with the spatial aggregation of conspecifics, particularly at scales which facilitate the post-settlement dispersal of fishes. Niche-based segregation of species along the depth gradient was found to be the primary driver of compositional turnover among both protected and exploited communities. However, spatial structuring within reefs, which was independent of variation in the environment, suggests that compositional differences among communities are also influenced by the limited post-settlement dispersal of resident fishes to adjacent areas during their ontogeny. Together, the results suggest that the diversity of reef-associated sparids is likely to depend both on an adequate diversity of suitable reef habitat and a sufficient degree of spatial connectivity to facilitate ontogenetic habitat shifts. Taxon-based descriptors of diversity do not adequately account for ecological difference among conspecifics within size-structured populations. To test whether differences in body size facilitated coexistence among sparid fishes, the number of species which coexisted at the local scale was related to variation in the size structure of communities. In communities which have been historically protected from fishing, local coexistence between a greater number of species was promoted by reduced levels of intraspecific variation in size of fishes. This suggests that, among species with similar trophic requirements, further niche segregation along a prey-size and body-size gradient is likely to mitigate the direct impacts of competition for shared food resources. Among exploited communities, size structure did not influence the number of species which coexisted at the local scale. This finding suggests that fishing-induced mortality of larger-bodied fishes is likely to remove some of the constraints to colonisation which arise from asymmetries in competitive fitness between small and large-bodied fishes. Together, these results highlight the importance of post-settlement processes and population size structure to the maintenance of reef-associated fish diversity within contiguous rocky reef habitats.
- Full Text:
- Date Issued: 2018
Assessment of the long-term response to rehabilitation of two wetlands in KwaZulu-Natal, South Africa
- Authors: Cowden, Craig
- Date: 2018
- Subjects: Wetlands -- South Africa -- KwaZulu-Natal Wetland restoration -- South Africa -- KwaZulu-Natal Wetland management -- South Africa -- KwaZulu-Natal Wetland conservation -- South Africa -- KwaZulu-Natal Wetland ecology -- South Africa -- KwaZulu-Natal Ecosystem management -- South Africa -- KwaZulu-Natal
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/60606 , vital:27802
- Description: Assessing the outputs and outcomes of wetland rehabilitation activities is recognised by the 'Working for Wetlands' programme in South Africa as important, but to date has been limited. An assessment of the ecological outcomes and the structural outputs of the Working for Wetlands rehabilitation implemented in the Killarney and Kruisfontein wetlands, KwaZulu-Natal, in 2005 was undertaken. The assessment of outcomes included an evaluation of the changes in terms of ecological integrity and the supply of ecosystem services, using WET-Health and WET- EcoServices assessment techniques respectively, and vegetation composition. Improvements in hydrological and geomorphic integrity were recorded in both wetlands, resulting in improved ecosystem services delivery. However, investigation of vegetation composition using the Wetland Index Value and Floristic Quality Assessment Index showed that, seven years after rehabilitation, KiNamey's vegetation composition had improved, but Kruisfontein's vegetation was still largely dominated by pioneer species and appeared to be stable, but in a severely transformed state. The response of these wetlands has shown that sites for rehabilitation should be screened before work begins, and wetlands requiring intensive management of vegetation recovery should be assessed in terms of the objectives and the anticipated benefits of the project. The assessment of the outputs included an evaluation of structural integrity, survival and cost- effectiveness. Limited issues, mostly relating to deviations from the designs during construction, were identified with regards to the structural outputs at each of the wetlands. However, the spreader canals at both Killarney and Kruisfontein wetlands were not functioning as intended and concentrated flows from the spreader canals were evident in both wetlands. The use of spreader canals should therefore be carefully planned and implemented for future wetland rehabilitation projects. Consideration of ZAR per hectare equivalent re-instated/secured provided a useful initial means of determining the cost-effectiveness of the wetland rehabilitation. However, additional factors need to be considered, such as, the nature of the rehabilitation activities, the type and size of the problem being addressed, rehabilitation of priority wetlands, limitations imposed by funders, and risks that need to be addressed by the rehabilitation strategy. Furthermore, the evaluation of the Killarney and Kruisfontein wetlands highlighted the need to revise the Water Research Commission's Wetland Management Series, especially those documents or guidelines relating to rehabilitation planning (WET-RehabPlan), interventions (WET-RehabMethods), and monitoring and evaluation (WET-RehabEvaluate).
- Full Text:
- Date Issued: 2018
- Authors: Cowden, Craig
- Date: 2018
- Subjects: Wetlands -- South Africa -- KwaZulu-Natal Wetland restoration -- South Africa -- KwaZulu-Natal Wetland management -- South Africa -- KwaZulu-Natal Wetland conservation -- South Africa -- KwaZulu-Natal Wetland ecology -- South Africa -- KwaZulu-Natal Ecosystem management -- South Africa -- KwaZulu-Natal
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/60606 , vital:27802
- Description: Assessing the outputs and outcomes of wetland rehabilitation activities is recognised by the 'Working for Wetlands' programme in South Africa as important, but to date has been limited. An assessment of the ecological outcomes and the structural outputs of the Working for Wetlands rehabilitation implemented in the Killarney and Kruisfontein wetlands, KwaZulu-Natal, in 2005 was undertaken. The assessment of outcomes included an evaluation of the changes in terms of ecological integrity and the supply of ecosystem services, using WET-Health and WET- EcoServices assessment techniques respectively, and vegetation composition. Improvements in hydrological and geomorphic integrity were recorded in both wetlands, resulting in improved ecosystem services delivery. However, investigation of vegetation composition using the Wetland Index Value and Floristic Quality Assessment Index showed that, seven years after rehabilitation, KiNamey's vegetation composition had improved, but Kruisfontein's vegetation was still largely dominated by pioneer species and appeared to be stable, but in a severely transformed state. The response of these wetlands has shown that sites for rehabilitation should be screened before work begins, and wetlands requiring intensive management of vegetation recovery should be assessed in terms of the objectives and the anticipated benefits of the project. The assessment of the outputs included an evaluation of structural integrity, survival and cost- effectiveness. Limited issues, mostly relating to deviations from the designs during construction, were identified with regards to the structural outputs at each of the wetlands. However, the spreader canals at both Killarney and Kruisfontein wetlands were not functioning as intended and concentrated flows from the spreader canals were evident in both wetlands. The use of spreader canals should therefore be carefully planned and implemented for future wetland rehabilitation projects. Consideration of ZAR per hectare equivalent re-instated/secured provided a useful initial means of determining the cost-effectiveness of the wetland rehabilitation. However, additional factors need to be considered, such as, the nature of the rehabilitation activities, the type and size of the problem being addressed, rehabilitation of priority wetlands, limitations imposed by funders, and risks that need to be addressed by the rehabilitation strategy. Furthermore, the evaluation of the Killarney and Kruisfontein wetlands highlighted the need to revise the Water Research Commission's Wetland Management Series, especially those documents or guidelines relating to rehabilitation planning (WET-RehabPlan), interventions (WET-RehabMethods), and monitoring and evaluation (WET-RehabEvaluate).
- Full Text:
- Date Issued: 2018
Discontinuous gully erosion as a mechanism of wetland formation: a case study of the Kompanjiesdrif basin, Kromrivier, Eastern Cape, South Africa
- Authors: Lagesse, Juliette V
- Date: 2018
- Subjects: Arroyos -- South Africa -- Kromme River (Eastern Cape) , Arroyos -- Erosion -- South Africa -- Kromme River (Eastern Cape) , Climatic geomorphology -- South Africa -- Kromme River (Eastern Cape) , Sedimentation and deposition -- South Africa -- Kromme River (Eastern Cape) , Alluvial fans -- South Africa -- Kromme River (Eastern Cape) , Wetland ecology -- South Africa -- Kromme River (Eastern Cape) , Rhizophoraceae , Palmiet (Prionium serratum)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/60540 , vital:27791
- Description: The Kompanjiesdrif basin is an unchannelled valley bottom palmiet wetland located near the headwaters of the Kromrivier in the Eastern Cape of South Africa. The wetland itself is underlain by Bokkeveld shales with the bordering mountain ranges comprising more resistant Table Mountain Group quarzitic sandstones. The valley is relatively planar and broad in form over a width of approximately 200 m. None of the existing controls that are considered to lead to valley widening and longitudinal slope reduction are immediately apparent. The basin lies on the Post Africa II erosion surface; with no evidence of a resistant lithology which might act as a local base level, limiting rates of vertical erosion and inducing lateral planing in upstream reaches via a meandering channel. The possible role of sagging of the basin due to long term deep chemical weathering of bedrock is discounted as the lithologies in the basin are sedimentary in origin and thus not susceptible to chemical weathering. The degree to which climate and sea level changes affected rates of incision and subsequent slope reduction is unclear, although their potential influence should be acknowledged. This study examined the geomorphic dynamics as discerned from the sedimentary record and morphology of the wetland basin, which provide a snapshot into the long-term processes which lowered the longitudinal slope and widened this valley. Coring within the wetland to depths of 1 - 3.3 m revealed that the sedimentary fill generally comprised an upward fining sequence, with sand or fine sand at the base, grading into silt and clay and organic material in the upper sections of cores. Occasional instances of multiple fine sand layers were observed in a few of the cores. An increase in the organic content of material from the north to the south side of the wetland and the occurrence of multiple thin layers of sand in the stratigraphy, highlighted the role of the northern tributary alluvial fans in influencing valley form. Sediment from north bank alluvial fans seem to periodically, partially impound the wetland basin. Surveyed transects across the wetland basin along with subsurface coring to the depth to refusal, illustrated a localised increase in longitudinal slope downstream of the nodes of tributary alluvial fan deposits, which impinge on the trunk stream basin. Coupled with the presence of deep, drowned, trench-like features (up to 8 m deep) beneath floating mats of palmiet, which were predominantly free of sedimentary fill and found opposite tributary alluvial fans; confirmed that the northern tributaries play a major role in the structure and geomorphic dynamics of the basin. The trench-like features appeared to be remnants of deep, narrow, discontinuous gullies. Dating of sediment from the base of these features (460-7040 BP) confirmed that they were formed prior to European settlement in the area. Therefore, it is suggested that the localised increase in longitudinal slope, caused by sediment deposition on the alluvial fans, transgresses a geomorphic threshold slope and that gully erosion is thus initiated. The process of repeated gully erosion leads to planing of bedrock and longitudinal slope reduction. Gully erosion forms an integral component of a cycle of deposition and incision referred to as “cut-and-fill”. During each iteration of the cycle of cutting and filling, gullies form in novel locations leading to gradual valley widening. Over geological time scales, the planing of bedrock and resultant valley widening creates a broad planar valley with a very low longitudinal slope; producing conditions suitable for unchannelled valley bottom wetland formation.
- Full Text:
- Date Issued: 2018
- Authors: Lagesse, Juliette V
- Date: 2018
- Subjects: Arroyos -- South Africa -- Kromme River (Eastern Cape) , Arroyos -- Erosion -- South Africa -- Kromme River (Eastern Cape) , Climatic geomorphology -- South Africa -- Kromme River (Eastern Cape) , Sedimentation and deposition -- South Africa -- Kromme River (Eastern Cape) , Alluvial fans -- South Africa -- Kromme River (Eastern Cape) , Wetland ecology -- South Africa -- Kromme River (Eastern Cape) , Rhizophoraceae , Palmiet (Prionium serratum)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/60540 , vital:27791
- Description: The Kompanjiesdrif basin is an unchannelled valley bottom palmiet wetland located near the headwaters of the Kromrivier in the Eastern Cape of South Africa. The wetland itself is underlain by Bokkeveld shales with the bordering mountain ranges comprising more resistant Table Mountain Group quarzitic sandstones. The valley is relatively planar and broad in form over a width of approximately 200 m. None of the existing controls that are considered to lead to valley widening and longitudinal slope reduction are immediately apparent. The basin lies on the Post Africa II erosion surface; with no evidence of a resistant lithology which might act as a local base level, limiting rates of vertical erosion and inducing lateral planing in upstream reaches via a meandering channel. The possible role of sagging of the basin due to long term deep chemical weathering of bedrock is discounted as the lithologies in the basin are sedimentary in origin and thus not susceptible to chemical weathering. The degree to which climate and sea level changes affected rates of incision and subsequent slope reduction is unclear, although their potential influence should be acknowledged. This study examined the geomorphic dynamics as discerned from the sedimentary record and morphology of the wetland basin, which provide a snapshot into the long-term processes which lowered the longitudinal slope and widened this valley. Coring within the wetland to depths of 1 - 3.3 m revealed that the sedimentary fill generally comprised an upward fining sequence, with sand or fine sand at the base, grading into silt and clay and organic material in the upper sections of cores. Occasional instances of multiple fine sand layers were observed in a few of the cores. An increase in the organic content of material from the north to the south side of the wetland and the occurrence of multiple thin layers of sand in the stratigraphy, highlighted the role of the northern tributary alluvial fans in influencing valley form. Sediment from north bank alluvial fans seem to periodically, partially impound the wetland basin. Surveyed transects across the wetland basin along with subsurface coring to the depth to refusal, illustrated a localised increase in longitudinal slope downstream of the nodes of tributary alluvial fan deposits, which impinge on the trunk stream basin. Coupled with the presence of deep, drowned, trench-like features (up to 8 m deep) beneath floating mats of palmiet, which were predominantly free of sedimentary fill and found opposite tributary alluvial fans; confirmed that the northern tributaries play a major role in the structure and geomorphic dynamics of the basin. The trench-like features appeared to be remnants of deep, narrow, discontinuous gullies. Dating of sediment from the base of these features (460-7040 BP) confirmed that they were formed prior to European settlement in the area. Therefore, it is suggested that the localised increase in longitudinal slope, caused by sediment deposition on the alluvial fans, transgresses a geomorphic threshold slope and that gully erosion is thus initiated. The process of repeated gully erosion leads to planing of bedrock and longitudinal slope reduction. Gully erosion forms an integral component of a cycle of deposition and incision referred to as “cut-and-fill”. During each iteration of the cycle of cutting and filling, gullies form in novel locations leading to gradual valley widening. Over geological time scales, the planing of bedrock and resultant valley widening creates a broad planar valley with a very low longitudinal slope; producing conditions suitable for unchannelled valley bottom wetland formation.
- Full Text:
- Date Issued: 2018
The National Skills Fund and green skills: towards a generative mechanism approach
- Authors: Sauls, Gideon George
- Date: 2018
- Subjects: South Africa. National Skills Fund , Environmental education Finance South Africa , Green technology Study and teaching South Africa , Postsecondary education South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63740 , vital:28482
- Description: The aim of the study was to investigate the role of the South African National Skills Fund (NSF) in responding to green skills training for the sake of better integration and optimal effectiveness in relation to the green economy in South Africa. The NSF is a multi-billion rand fund for skills development, with the responsibility to respond effectively to the country’s skills development needs. Part of the NSF’s mandate is to ensure the development of green skills in South Africa, with special reference to the allocation of grants, as a key mechanism in ensuring adherence to properly governed skills development funding requirements. This study considers the identification of green skills funding as a skills planning and implementation challenge within the post-school education and training context, the NSF, the green economy and related skills debates, both locally and globally. The study contributes to a growing body of research in South Africa that seeks a wider systemic perspective on green skills concerns. The NSF and its functioning is a critical dimension of the wider skills system and is a significant system element influencing further emergence of a coherent national system for green skills development. Providing further rationale for this study is the 2011 finding of the International Labour Organisation, that the green skills development system in South Africa is re-active and poorly systematised, a finding that was also noted in the first ever Environmental Sector Skills Plan for South Africa undertaken by the Department of Environmental Affairs in 2010. As the study is mainly focused on one aspect of the policy system, namely the NSF’s role in green skills funding, the bulk of the data used in this study is documentary. Research information was obtained from NSF documentary sources to describe the NSF organisationally. Information was also obtained from green skills documentary sources to obtain a better understanding of the nature and purpose of the development of green skills in South Africa. The study has also drawn on references related to grant management as a mechanism for seeding meaningful transformations and skills development research in South Africa to understand the skills development landscape, with special reference to the Department of Higher Education and Training’s (DHET) post-school education and training system. Documentary data was supplemented by selected key respondent interviews from the skills sector and from the green skills research community to provide further perspective on the research focus. Critical realism (CR) is utilised as a meta-theoretical framework that seeks to inform the overall academic reflection and interpretation process. The work of Danermark, Ekström, Jakobsen and Karlsson (2002), which describes the process of data analysis in critical realism, was adapted into a four-phased research approach for this particular policy study, which I framed as a Quadrilateral Policy Analysis Framework (QPAF). This provided a data analysis framework which allowed for taking account of the mechanisms shaping the NSF as an important systemic funding agency within South Africa’s emerging post-school education and training context, as this relates to green skills. However, to further analyse this research question and context, I needed to work with substantive policy theory. Given the nature of the policy object that I was investigating, I found Feiock’s (2013) Institutional Collective Action Framework to be a helpful substantive policy theory as it has adequate nuance with which I could describe the NSF’s core function, namely that of grant-making for the post-schooling policy context. Based on the critical realist meta-theoretical framework and the substantive policy theoretical frameworks, I developed four phases of analysis, namely a) descriptive analysis which is divided into Part A (describing the green skills landscape and its funding demands ) and Part B (describing the NSF as it relates to green skills); b) component analysis which further analyses key components of the above; c) abductive policy analysis which identifies critical mechanisms and how they operate; and d) generative mechanism analysis which identifies the underlying generative mechanisms shaping the NSF’s engagement with green skills (or lack thereof). The following main findings are identified: • It emerged that the responsiveness of the NSF to green skills is emergent, essential and yet multifaceted due to competing stakeholder interests, expectations and claims; • Key strategic relations with critical role players within South Africa’s skills levy funding matrix emerged as a fundamental requirement towards the achievement of the NSF’s organisational mandate to respond effectively to national green skills needs and expectations; • Contracting is the central mechanism driving the NSF grant-making process. Related to this is the finding that partnerships emerged as the most versatile and underutilised mechanism that cuts across all four of the NSF grant-making phases; • The NSF’s current method of making sense of funding policy indications as per national policy documents is too reductionist because the method betrays an alignment-mirroring form of sense-making awareness that uncritically endorses substratum philosophical assumptions like Human Capital Theory (HCT) and associated neoclassical economic theories embedded in the policy frameworks. These assumptions contradict and potentially limit engagement with wider theories and policy frameworks for guiding skills development that are oriented towards the wider common good as argued by non-anthropocentric orientations in critical realism and the green skills sector. In summary, an argument is put forward that the NSF is a key funding mechanism towards green skills delivery in South Africa, but that this funding mechanism is under-utilised and inadequately mobilised for transitioning towards sustainability in South Africa. The study recommends that, in pursuit of better integration and optimal effectiveness thereof and in line with the fund’s legislative, organisational and public mandate, a consensual negotiation skills planning mechanism be considered from an institutional collective action response platform. In terms of recommendations for further research, it is proposed that a comparative analysis study could be considered between the NSF and other leading global funding agencies or other national skills funding mechanisms that are also concerned with the inclusion of green skills development. Comparative studies of this nature could potentially enhance the fund’s policy-making process and assist in the development of more appropriate institutional arrangements towards optimal funding responsiveness. Lastly, in the light of the NSF’s current contribution to green skills in the country, an impact evaluation study on the return on green skills investment presents an additional intriguing research endeavour which would contribute further perspective on the arguments presented in this study.
- Full Text:
- Date Issued: 2018
- Authors: Sauls, Gideon George
- Date: 2018
- Subjects: South Africa. National Skills Fund , Environmental education Finance South Africa , Green technology Study and teaching South Africa , Postsecondary education South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63740 , vital:28482
- Description: The aim of the study was to investigate the role of the South African National Skills Fund (NSF) in responding to green skills training for the sake of better integration and optimal effectiveness in relation to the green economy in South Africa. The NSF is a multi-billion rand fund for skills development, with the responsibility to respond effectively to the country’s skills development needs. Part of the NSF’s mandate is to ensure the development of green skills in South Africa, with special reference to the allocation of grants, as a key mechanism in ensuring adherence to properly governed skills development funding requirements. This study considers the identification of green skills funding as a skills planning and implementation challenge within the post-school education and training context, the NSF, the green economy and related skills debates, both locally and globally. The study contributes to a growing body of research in South Africa that seeks a wider systemic perspective on green skills concerns. The NSF and its functioning is a critical dimension of the wider skills system and is a significant system element influencing further emergence of a coherent national system for green skills development. Providing further rationale for this study is the 2011 finding of the International Labour Organisation, that the green skills development system in South Africa is re-active and poorly systematised, a finding that was also noted in the first ever Environmental Sector Skills Plan for South Africa undertaken by the Department of Environmental Affairs in 2010. As the study is mainly focused on one aspect of the policy system, namely the NSF’s role in green skills funding, the bulk of the data used in this study is documentary. Research information was obtained from NSF documentary sources to describe the NSF organisationally. Information was also obtained from green skills documentary sources to obtain a better understanding of the nature and purpose of the development of green skills in South Africa. The study has also drawn on references related to grant management as a mechanism for seeding meaningful transformations and skills development research in South Africa to understand the skills development landscape, with special reference to the Department of Higher Education and Training’s (DHET) post-school education and training system. Documentary data was supplemented by selected key respondent interviews from the skills sector and from the green skills research community to provide further perspective on the research focus. Critical realism (CR) is utilised as a meta-theoretical framework that seeks to inform the overall academic reflection and interpretation process. The work of Danermark, Ekström, Jakobsen and Karlsson (2002), which describes the process of data analysis in critical realism, was adapted into a four-phased research approach for this particular policy study, which I framed as a Quadrilateral Policy Analysis Framework (QPAF). This provided a data analysis framework which allowed for taking account of the mechanisms shaping the NSF as an important systemic funding agency within South Africa’s emerging post-school education and training context, as this relates to green skills. However, to further analyse this research question and context, I needed to work with substantive policy theory. Given the nature of the policy object that I was investigating, I found Feiock’s (2013) Institutional Collective Action Framework to be a helpful substantive policy theory as it has adequate nuance with which I could describe the NSF’s core function, namely that of grant-making for the post-schooling policy context. Based on the critical realist meta-theoretical framework and the substantive policy theoretical frameworks, I developed four phases of analysis, namely a) descriptive analysis which is divided into Part A (describing the green skills landscape and its funding demands ) and Part B (describing the NSF as it relates to green skills); b) component analysis which further analyses key components of the above; c) abductive policy analysis which identifies critical mechanisms and how they operate; and d) generative mechanism analysis which identifies the underlying generative mechanisms shaping the NSF’s engagement with green skills (or lack thereof). The following main findings are identified: • It emerged that the responsiveness of the NSF to green skills is emergent, essential and yet multifaceted due to competing stakeholder interests, expectations and claims; • Key strategic relations with critical role players within South Africa’s skills levy funding matrix emerged as a fundamental requirement towards the achievement of the NSF’s organisational mandate to respond effectively to national green skills needs and expectations; • Contracting is the central mechanism driving the NSF grant-making process. Related to this is the finding that partnerships emerged as the most versatile and underutilised mechanism that cuts across all four of the NSF grant-making phases; • The NSF’s current method of making sense of funding policy indications as per national policy documents is too reductionist because the method betrays an alignment-mirroring form of sense-making awareness that uncritically endorses substratum philosophical assumptions like Human Capital Theory (HCT) and associated neoclassical economic theories embedded in the policy frameworks. These assumptions contradict and potentially limit engagement with wider theories and policy frameworks for guiding skills development that are oriented towards the wider common good as argued by non-anthropocentric orientations in critical realism and the green skills sector. In summary, an argument is put forward that the NSF is a key funding mechanism towards green skills delivery in South Africa, but that this funding mechanism is under-utilised and inadequately mobilised for transitioning towards sustainability in South Africa. The study recommends that, in pursuit of better integration and optimal effectiveness thereof and in line with the fund’s legislative, organisational and public mandate, a consensual negotiation skills planning mechanism be considered from an institutional collective action response platform. In terms of recommendations for further research, it is proposed that a comparative analysis study could be considered between the NSF and other leading global funding agencies or other national skills funding mechanisms that are also concerned with the inclusion of green skills development. Comparative studies of this nature could potentially enhance the fund’s policy-making process and assist in the development of more appropriate institutional arrangements towards optimal funding responsiveness. Lastly, in the light of the NSF’s current contribution to green skills in the country, an impact evaluation study on the return on green skills investment presents an additional intriguing research endeavour which would contribute further perspective on the arguments presented in this study.
- Full Text:
- Date Issued: 2018
Schooling and institution quality linked to earnings in the Eastern Cape
- Authors: Cuthbert, Carol
- Date: 2018
- Subjects: Wages -- Effect of education on -- South Africa -- Eastern Cape Education, Higher -- Economic aspects -- South Africa -- Eastern Cape Equality -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/62166 , vital:28134
- Description: Return to investment for tertiary education is not equal for all. Human Capital Theory imposes a linear pathway between education and earnings, that fails to recognise other sources of capital, ignores social returns and does not explain why socio-economic variables influence employability and earnings. Those returns, rather than simply incrementally delivering returns for additional years of education, are however heterogeneous across students, with field of study, gender and population group influencing earnings; and schooling type and university attended filtering whether one finds a job. This study utilises data from Rhodes University and the University of Fort Hare, illustrating the extreme positions within the South African education landscape, employing a Heckman selection to predict the returns on education. The regression is found to be partially successful in predicting a graduate’s ability to find a job, in the first instance, and thereafter their returns. It is crucial to analyse the heterogeneity of socio-economic parameters to understand aspects of the economy, and develop education policies to take advantage of this understanding, especially against the backdrop of the student protests being experienced in the country and the funding models proposed. Access to tertiary education, through policy inducement, such as the recent increase of the grant limit from R122 000 to R350 000, requires disaggregated returns to education to be investigated.
- Full Text:
- Date Issued: 2018
- Authors: Cuthbert, Carol
- Date: 2018
- Subjects: Wages -- Effect of education on -- South Africa -- Eastern Cape Education, Higher -- Economic aspects -- South Africa -- Eastern Cape Equality -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/62166 , vital:28134
- Description: Return to investment for tertiary education is not equal for all. Human Capital Theory imposes a linear pathway between education and earnings, that fails to recognise other sources of capital, ignores social returns and does not explain why socio-economic variables influence employability and earnings. Those returns, rather than simply incrementally delivering returns for additional years of education, are however heterogeneous across students, with field of study, gender and population group influencing earnings; and schooling type and university attended filtering whether one finds a job. This study utilises data from Rhodes University and the University of Fort Hare, illustrating the extreme positions within the South African education landscape, employing a Heckman selection to predict the returns on education. The regression is found to be partially successful in predicting a graduate’s ability to find a job, in the first instance, and thereafter their returns. It is crucial to analyse the heterogeneity of socio-economic parameters to understand aspects of the economy, and develop education policies to take advantage of this understanding, especially against the backdrop of the student protests being experienced in the country and the funding models proposed. Access to tertiary education, through policy inducement, such as the recent increase of the grant limit from R122 000 to R350 000, requires disaggregated returns to education to be investigated.
- Full Text:
- Date Issued: 2018
Suicide and the South African business cycle: a time series approach, 2006-2015
- Authors: Pitot, Amaury
- Date: 2018
- Subjects: Suicide -- South Africa , Business cycles -- South Africa , Autoregression (Statistics) , Divorce -- South Africa , AutoRegressive Distributed Lagged model (ARDL)
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/62286 , vital:28150
- Description: Suicide is a major public health issue and imposes substantial economic cost on society every year. For example, the World Health Organisation has estimated that there are over one million completed suicides every year, of which about 75% occur in middle and low income countries. In South Africa, suicide is one of the leading causes of non-natural death, but remains under-researched from an economic point of view due to limited data availability. Using monthly data for the period 2006-2015, this study explores whether there is a relationship between suicide and the South African business cycle. This is further broken down to examine how, if at all, this relationship with the business cycle differs across age-, gender-, and racial groups. The primary source of data for suicide and demographic groups were obtained from Statistics South Africa’s Mortality and Causes of Death Data from Death Notification released since 2006. The coincident indicator was used as a proxy for the business cycle as it represents the business cycle in real time. Using an autoregressive distributed lagged model (ARDL), a long run relationship was established with suicide being a function of the coincident indicator, divorce and fertility rate. The findings of this paper show that the overall suicide rate moves with the South African business cycle (i.e. pro-cyclical relationship) in the long run. This relationship holds for males, the black population group and the 15-29 and 30-44 age categories. In addition, the divorce rate had a positive and significant relationship with the overall suicide rate, as well as suicide among the black population group and for the 30-44 age category, whereas fertility rates had no significant relationship with suicide.
- Full Text:
- Date Issued: 2018
- Authors: Pitot, Amaury
- Date: 2018
- Subjects: Suicide -- South Africa , Business cycles -- South Africa , Autoregression (Statistics) , Divorce -- South Africa , AutoRegressive Distributed Lagged model (ARDL)
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/62286 , vital:28150
- Description: Suicide is a major public health issue and imposes substantial economic cost on society every year. For example, the World Health Organisation has estimated that there are over one million completed suicides every year, of which about 75% occur in middle and low income countries. In South Africa, suicide is one of the leading causes of non-natural death, but remains under-researched from an economic point of view due to limited data availability. Using monthly data for the period 2006-2015, this study explores whether there is a relationship between suicide and the South African business cycle. This is further broken down to examine how, if at all, this relationship with the business cycle differs across age-, gender-, and racial groups. The primary source of data for suicide and demographic groups were obtained from Statistics South Africa’s Mortality and Causes of Death Data from Death Notification released since 2006. The coincident indicator was used as a proxy for the business cycle as it represents the business cycle in real time. Using an autoregressive distributed lagged model (ARDL), a long run relationship was established with suicide being a function of the coincident indicator, divorce and fertility rate. The findings of this paper show that the overall suicide rate moves with the South African business cycle (i.e. pro-cyclical relationship) in the long run. This relationship holds for males, the black population group and the 15-29 and 30-44 age categories. In addition, the divorce rate had a positive and significant relationship with the overall suicide rate, as well as suicide among the black population group and for the 30-44 age category, whereas fertility rates had no significant relationship with suicide.
- Full Text:
- Date Issued: 2018
Using reading to learn pedagogy to enhance the English first additional language teachers’ classroom practice
- Authors: Mawela, Rethabile Rejoice
- Date: 2018
- Subjects: Reading to learn , Language transfer (Language learning) -- South Africa -- Kuruman , Language teachers -- South Africa -- Kuruman , Language and languages -- Study and teaching -- Bilingual method , Second language acquisition
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63415 , vital:28409
- Description: Drawing from the Hallidayan, Bernsteinian and Vygotskyan theories of Systemic Functional Linguistics, Pedagogic Discourse and Social Learning, this study examined the role that Rose's (2005) Reading to Learn (RtL) pedagogy could play in the development of teachers’ pedagogic practices in the teaching of English First Additional Language. The study participants teach English First Additional Language in Black, materially and economically disadvantaged rural primary schools in Kuruman, the Northern Cape Province, South Africa. As study participants, 4 intermediate phase and 4 senior phase teachers of English First Additional Language were purposively selected from 6 rural schools. Located within the Critical Paradigm, Subjective Epistemology and Mixed-Method approach, the study used documentary evidence, semi- structured interviews and RtL pedagogy as research instruments. Research findings reveal that RtL enriched and advanced teachers’ pedagogic practice in the teaching of reading and writing. As a consequence, teachers’ classroom practice of the 8 study participants improved as evidenced as their content knowledge expanded, the quality of teaching developed and their perceptions of themselves as professionals was transformed. An accompanying finding is that teachers acquired the tools to teach reading and the reading and writing proficiencies of learners in their classrooms improved.
- Full Text:
- Date Issued: 2018
- Authors: Mawela, Rethabile Rejoice
- Date: 2018
- Subjects: Reading to learn , Language transfer (Language learning) -- South Africa -- Kuruman , Language teachers -- South Africa -- Kuruman , Language and languages -- Study and teaching -- Bilingual method , Second language acquisition
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63415 , vital:28409
- Description: Drawing from the Hallidayan, Bernsteinian and Vygotskyan theories of Systemic Functional Linguistics, Pedagogic Discourse and Social Learning, this study examined the role that Rose's (2005) Reading to Learn (RtL) pedagogy could play in the development of teachers’ pedagogic practices in the teaching of English First Additional Language. The study participants teach English First Additional Language in Black, materially and economically disadvantaged rural primary schools in Kuruman, the Northern Cape Province, South Africa. As study participants, 4 intermediate phase and 4 senior phase teachers of English First Additional Language were purposively selected from 6 rural schools. Located within the Critical Paradigm, Subjective Epistemology and Mixed-Method approach, the study used documentary evidence, semi- structured interviews and RtL pedagogy as research instruments. Research findings reveal that RtL enriched and advanced teachers’ pedagogic practice in the teaching of reading and writing. As a consequence, teachers’ classroom practice of the 8 study participants improved as evidenced as their content knowledge expanded, the quality of teaching developed and their perceptions of themselves as professionals was transformed. An accompanying finding is that teachers acquired the tools to teach reading and the reading and writing proficiencies of learners in their classrooms improved.
- Full Text:
- Date Issued: 2018
Measuring the elasticity of electricity demand in South Africa: implications for future demand and supply
- Authors: Kosiorek, Sebastian
- Date: 2018
- Subjects: Electric power consumption -- South Africa , Electric power distribution -- South Africa , Electric power production -- South Africa , Electric power failures -- South Africa , Electric utilities -- Law and legislation -- South Africa , Autoregression (Statistics) , Renewable energy sources -- South Africa , Energy policy -- South Africa , Integrated Resource Plan
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/62472 , vital:28196
- Description: A key economic issue for government is the ability to effectively match electricity supply to electricity demand, because of the substantial economic losses in the case of where there is too little supply, or the waste of scarce resources where there is too much supply. In the case of South Africa, this issue, the importance of which was highlighted by the power shortages and associated “rolling blackouts” experience in 2008, has led to the creation of the Integrated Resource Plan (IRP) as a means to decide how energy policy will be developed. Recently, however, the IRP 2010 and its subsequent 2013 and 2016 (draft) updates have been criticised as being too optimistic in regards to their projections of economic growth and electricity demand, making the recommendations in these documents to be flawed. Using monthly data from January 1990 to May 2017, together with Autoregressive Distributed Lag (ARDL) bounds testing for cointegration, this paper measures changes in the elasticity of electricity demand as a result of the massive price hikes over the past decade. Thereafter, the implications of changed electricity as well as possibly lower Gross Domestic Product (GDP) growth in the future for forecasts of possible future demand for electricity are examined. From these revised forecasts, it is possible to make appropriate recommendations in regards to electricity supply policy for South Africa including what possible energy mix is needed as well as the requirements for creating new supply to meet possible future demand. It is concluded that future electricity demand is likely to be much lower than forecast in the IRP 2010 and IRP 2013 documents. The degree of uncertainty in electricity demand growth suggests that large-scale increases in supply capacity taking years to construct, such as coal or nuclear, should be avoided. Small, incremental increases in supply that are able to come on stream swiftly, such as gas, solar and wind power, are likely to be more appropriate for meeting South Africa’s future needs.
- Full Text:
- Date Issued: 2018
- Authors: Kosiorek, Sebastian
- Date: 2018
- Subjects: Electric power consumption -- South Africa , Electric power distribution -- South Africa , Electric power production -- South Africa , Electric power failures -- South Africa , Electric utilities -- Law and legislation -- South Africa , Autoregression (Statistics) , Renewable energy sources -- South Africa , Energy policy -- South Africa , Integrated Resource Plan
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/62472 , vital:28196
- Description: A key economic issue for government is the ability to effectively match electricity supply to electricity demand, because of the substantial economic losses in the case of where there is too little supply, or the waste of scarce resources where there is too much supply. In the case of South Africa, this issue, the importance of which was highlighted by the power shortages and associated “rolling blackouts” experience in 2008, has led to the creation of the Integrated Resource Plan (IRP) as a means to decide how energy policy will be developed. Recently, however, the IRP 2010 and its subsequent 2013 and 2016 (draft) updates have been criticised as being too optimistic in regards to their projections of economic growth and electricity demand, making the recommendations in these documents to be flawed. Using monthly data from January 1990 to May 2017, together with Autoregressive Distributed Lag (ARDL) bounds testing for cointegration, this paper measures changes in the elasticity of electricity demand as a result of the massive price hikes over the past decade. Thereafter, the implications of changed electricity as well as possibly lower Gross Domestic Product (GDP) growth in the future for forecasts of possible future demand for electricity are examined. From these revised forecasts, it is possible to make appropriate recommendations in regards to electricity supply policy for South Africa including what possible energy mix is needed as well as the requirements for creating new supply to meet possible future demand. It is concluded that future electricity demand is likely to be much lower than forecast in the IRP 2010 and IRP 2013 documents. The degree of uncertainty in electricity demand growth suggests that large-scale increases in supply capacity taking years to construct, such as coal or nuclear, should be avoided. Small, incremental increases in supply that are able to come on stream swiftly, such as gas, solar and wind power, are likely to be more appropriate for meeting South Africa’s future needs.
- Full Text:
- Date Issued: 2018
A review of the re-structuring of the Nelson Mandela Academic Hospital through the change management approach
- Authors: Nodikida, Mzulungile
- Date: 2018
- Subjects: Organizational change -- Case studies , Organizational change -- Management , Reengineering (Management) -- South Africa -- Mthatha , Leadership -- South Africa -- Mthatha , Organizational behavior -- South Africa -- Mthatha , Corporate culture -- South Africa -- Mthatha , Nelson Mandela Academic Hospital
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/58339 , vital:27236
- Description: The research used a change management approach to analyze the restructuring of the Nelson Mandela Academic Hospital from a tertiary to a central hospital. The study was underpinned by two objectives. Firstly, to analyze the restructuring of the Nelson Mandela Academic Hospital from a tertiary to a "central" hospital using the Core Elements Framework of change management developed by Antwi and Kale (2014). Secondly, to use the knowledge gained through literature review combined with the experiences of the managers at Nelson Mandela Academic Hospital to inform future healthcare reforms in general and particularly in the restructuring of hospitals. The Core Elements Framework by Antwi and Kale (2014) identifies six fundamental change elements from both emergent and planned change management approaches. The six elements are regarded by theorists from the two different schools of thought i.e. emergent change and planned change as key for successful change. The Core Elements Framework by Antwi and Kale, (2014) demonstrates the strength of not viewing the two approaches to change management as mutually exclusive but as complementing each other when the other is falling short. The study identified the following: ■ The change was prompted by clearly identifiable external factors more than internal factors. ■ There was notable lack of organizational harmony which may have negatively impacted the change process. ■ The Private Public Partnership (PPP) funding model which was aimed at delivering the central hospital collapsed, after a study discovered that it benefited the private sector more than the public sector. ■ There was no proper consultation of major stakeholders for preparation of the change. ■ Resources in all material forms were not made available for the change to take off, this means that there was no organizational capacity to execute the change. The study draws the conclusion that lack of organizational capacity, organizational harmony and a proper consultation process for stakeholders are the main reasons why the restructuring of the Nelson Mandela Academic Hospital is not yielding the desired results. The study recommends that organizations should implement a multidimensional approach for any change initiative to be successful and that organizations must ensure the availability of the necessary resources when embarking on change.
- Full Text:
- Date Issued: 2018
- Authors: Nodikida, Mzulungile
- Date: 2018
- Subjects: Organizational change -- Case studies , Organizational change -- Management , Reengineering (Management) -- South Africa -- Mthatha , Leadership -- South Africa -- Mthatha , Organizational behavior -- South Africa -- Mthatha , Corporate culture -- South Africa -- Mthatha , Nelson Mandela Academic Hospital
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/58339 , vital:27236
- Description: The research used a change management approach to analyze the restructuring of the Nelson Mandela Academic Hospital from a tertiary to a central hospital. The study was underpinned by two objectives. Firstly, to analyze the restructuring of the Nelson Mandela Academic Hospital from a tertiary to a "central" hospital using the Core Elements Framework of change management developed by Antwi and Kale (2014). Secondly, to use the knowledge gained through literature review combined with the experiences of the managers at Nelson Mandela Academic Hospital to inform future healthcare reforms in general and particularly in the restructuring of hospitals. The Core Elements Framework by Antwi and Kale (2014) identifies six fundamental change elements from both emergent and planned change management approaches. The six elements are regarded by theorists from the two different schools of thought i.e. emergent change and planned change as key for successful change. The Core Elements Framework by Antwi and Kale, (2014) demonstrates the strength of not viewing the two approaches to change management as mutually exclusive but as complementing each other when the other is falling short. The study identified the following: ■ The change was prompted by clearly identifiable external factors more than internal factors. ■ There was notable lack of organizational harmony which may have negatively impacted the change process. ■ The Private Public Partnership (PPP) funding model which was aimed at delivering the central hospital collapsed, after a study discovered that it benefited the private sector more than the public sector. ■ There was no proper consultation of major stakeholders for preparation of the change. ■ Resources in all material forms were not made available for the change to take off, this means that there was no organizational capacity to execute the change. The study draws the conclusion that lack of organizational capacity, organizational harmony and a proper consultation process for stakeholders are the main reasons why the restructuring of the Nelson Mandela Academic Hospital is not yielding the desired results. The study recommends that organizations should implement a multidimensional approach for any change initiative to be successful and that organizations must ensure the availability of the necessary resources when embarking on change.
- Full Text:
- Date Issued: 2018
Geometry of deformed special relativity
- Authors: Sixaba, Vuyile
- Date: 2018
- Subjects: Special relativity (Physics) , Quantum gravity , Quantum theory , Geometry , Heisenberg uncertainty principle
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/59478 , vital:27615
- Description: We undertake a study of the classical regime in which Planck's constant and Newton's gravitational constant are negligible, but not their ratio, the Planck mass, in hopes that this could possibly lead to testable quantum gravity (QG) effects in a classical regime. In this quest for QG phenomenology we consider modifications of the standard dispersion relation of a free particle known as deformed special relativity (DSR). We try to geometrize DSR to find the geometric origin of the spacetime and momentum space. In particular, we adopt the framework of Hamilton geometry which is set up on phase space, as the cotangent bundle of configuration space in order to derive a purely phase space formulation of DSR. This is necessary when one wants to understand potential links of DSR with modifications of quantum mechanics such as Generalised Uncertainty Principles. It is subsequently observed that space-time and momentum space emerge naturally as curved and intertwined spaces. In conclusion we mention examples and applications of this framework as well as potential future developments.
- Full Text:
- Date Issued: 2018
- Authors: Sixaba, Vuyile
- Date: 2018
- Subjects: Special relativity (Physics) , Quantum gravity , Quantum theory , Geometry , Heisenberg uncertainty principle
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/59478 , vital:27615
- Description: We undertake a study of the classical regime in which Planck's constant and Newton's gravitational constant are negligible, but not their ratio, the Planck mass, in hopes that this could possibly lead to testable quantum gravity (QG) effects in a classical regime. In this quest for QG phenomenology we consider modifications of the standard dispersion relation of a free particle known as deformed special relativity (DSR). We try to geometrize DSR to find the geometric origin of the spacetime and momentum space. In particular, we adopt the framework of Hamilton geometry which is set up on phase space, as the cotangent bundle of configuration space in order to derive a purely phase space formulation of DSR. This is necessary when one wants to understand potential links of DSR with modifications of quantum mechanics such as Generalised Uncertainty Principles. It is subsequently observed that space-time and momentum space emerge naturally as curved and intertwined spaces. In conclusion we mention examples and applications of this framework as well as potential future developments.
- Full Text:
- Date Issued: 2018
Graphene quantum dots and their metallophthalocyanines nanoconjugates as novel photoluminescent nanosensors
- Authors: Achadu, Ojodomo John
- Date: 2018
- Subjects: Quantum dots , Graphene , Phthalocyanines , Nanoconjugates , Novel photoluminescent nanosensors , Metallophthalocyanines
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60719 , vital:27821
- Description: The fabrication and application of graphene quantum dots (GQDs)-based photoluminescent probes for the detection of analytes is presented. GQDs were functionalized with complexes such as metallophthalocyanines (MPcs), metal nanoparticles (Au@Ag NPs), 2,2,6,6-tetramethyl(piperidin-1-yl)oxyl (TEMPO), maleimide and thymine for the sensing of target analytes such as ascorbic acid (AA), biothiols (cysteine, homocysteine and glutathione) and mercury ion (Hg²+). The design strategy and approach was based on the quenching of the fluorescence of the GQDs upon functionalization with the above-mentioned complexes, which could be restored in the presence of the target analytes (due to their specific interaction affinity with the complexes). For the detection of AA, GQDs were covalently and/or non-covalently conjugated to TEMPO-bearing complexes to form GQDs-4A-TEMPO and GQDs-TEMPO-MPc systems with nanomolar limits of detection. For the detection of biothiols, Au@Ag NPs and maleimide-bearing complexes (MPc), which have specific affinity to interact with biothiols, were deployed. Hg²+ detection involved the use of GQDs and/or MPcs with thiol and thymine groups, respectively. In addition, a smart sensing platform was designed for the dual detection of biothiols and Hg²+ using supramolecular hybrid of polyethyleneimine functionalized-GQDs and MPc-Au@Ag conjugate. The probe could detect, in a sequential manner, Hg²+ and biothiols with high sensitivity. Results obtained from the LODs of the probes showed that GQDs sensing performances could be enhanced in the presence of MPcs. The probes designed in this work were successfully deployed in the assays of the target analytes in real samples and the recoveries obtained confirmed the analytical applicability of the probes.
- Full Text:
- Date Issued: 2018
- Authors: Achadu, Ojodomo John
- Date: 2018
- Subjects: Quantum dots , Graphene , Phthalocyanines , Nanoconjugates , Novel photoluminescent nanosensors , Metallophthalocyanines
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60719 , vital:27821
- Description: The fabrication and application of graphene quantum dots (GQDs)-based photoluminescent probes for the detection of analytes is presented. GQDs were functionalized with complexes such as metallophthalocyanines (MPcs), metal nanoparticles (Au@Ag NPs), 2,2,6,6-tetramethyl(piperidin-1-yl)oxyl (TEMPO), maleimide and thymine for the sensing of target analytes such as ascorbic acid (AA), biothiols (cysteine, homocysteine and glutathione) and mercury ion (Hg²+). The design strategy and approach was based on the quenching of the fluorescence of the GQDs upon functionalization with the above-mentioned complexes, which could be restored in the presence of the target analytes (due to their specific interaction affinity with the complexes). For the detection of AA, GQDs were covalently and/or non-covalently conjugated to TEMPO-bearing complexes to form GQDs-4A-TEMPO and GQDs-TEMPO-MPc systems with nanomolar limits of detection. For the detection of biothiols, Au@Ag NPs and maleimide-bearing complexes (MPc), which have specific affinity to interact with biothiols, were deployed. Hg²+ detection involved the use of GQDs and/or MPcs with thiol and thymine groups, respectively. In addition, a smart sensing platform was designed for the dual detection of biothiols and Hg²+ using supramolecular hybrid of polyethyleneimine functionalized-GQDs and MPc-Au@Ag conjugate. The probe could detect, in a sequential manner, Hg²+ and biothiols with high sensitivity. Results obtained from the LODs of the probes showed that GQDs sensing performances could be enhanced in the presence of MPcs. The probes designed in this work were successfully deployed in the assays of the target analytes in real samples and the recoveries obtained confirmed the analytical applicability of the probes.
- Full Text:
- Date Issued: 2018
Factors that shape learner achievement in socially disadvantaged and rural contexts: a social realist study in two rural senior secondary schools in Omusati region, Namibia
- Authors: Shilongo, Erica
- Date: 2018
- Subjects: Academic achievement Namibia Omusati , High school students Namibia Omusati Social conditions , Rural schools Namibia Omusati , Education, Rural Namibia Omusati , Social realism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62240 , vital:28146
- Description: Learners’ performance and the reasons for either achievement or failure in school has lo ng been a topic of debate. In early research on academic achievement, theorists, educators, biologists and psychologists traditionally focused on the learners from socially disadvantaged family backgrounds who underachieve. Much of the debate internationally centred on whether learner academic achievement / underachievement is a product of hereditary traits or the social context. In particular, arguments for and against whether the reasons for the achievement / underachievement of children from socially disadvantaged families are genetic or the social context in which they find themselves continue unabated. Such explanations do not provide insight into why it is that despite familial (genetic) and social circumstances (social disadvantage), some children succeed and/or are able to act outside expectations of failure. Little research has focused on those in the same or similar contexts who are achieving academic success despite their limiting circumstances and the reasons for their success. This study used a social realist lens to investigate the factors that shape the academic achievement of 12 learners in two rural senior secondary schools in Omusati region, Namibia. All 12 learners are from low socioeconomic family backgrounds. The data was collected through survey, interviews with learners, parents and teachers, field notes and document analysis. The main finding of the study show that contrary to research that portrayed learners’ achievement as determined either by heredity or social contexts, the 12 learners constantly used their agentic possibilities to navigate constraining structural and cultural conditions at regional, familial and school levels to achieve academic success. Their agency was shaped by the socioeconomic conditions in their lives, namely, socioeconomic deprivation; large extended families in rural households, lack of amenities and utilities in their families, participation in household chores, experience of family tragedies and of changes when they were young.
- Full Text:
- Date Issued: 2018
- Authors: Shilongo, Erica
- Date: 2018
- Subjects: Academic achievement Namibia Omusati , High school students Namibia Omusati Social conditions , Rural schools Namibia Omusati , Education, Rural Namibia Omusati , Social realism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62240 , vital:28146
- Description: Learners’ performance and the reasons for either achievement or failure in school has lo ng been a topic of debate. In early research on academic achievement, theorists, educators, biologists and psychologists traditionally focused on the learners from socially disadvantaged family backgrounds who underachieve. Much of the debate internationally centred on whether learner academic achievement / underachievement is a product of hereditary traits or the social context. In particular, arguments for and against whether the reasons for the achievement / underachievement of children from socially disadvantaged families are genetic or the social context in which they find themselves continue unabated. Such explanations do not provide insight into why it is that despite familial (genetic) and social circumstances (social disadvantage), some children succeed and/or are able to act outside expectations of failure. Little research has focused on those in the same or similar contexts who are achieving academic success despite their limiting circumstances and the reasons for their success. This study used a social realist lens to investigate the factors that shape the academic achievement of 12 learners in two rural senior secondary schools in Omusati region, Namibia. All 12 learners are from low socioeconomic family backgrounds. The data was collected through survey, interviews with learners, parents and teachers, field notes and document analysis. The main finding of the study show that contrary to research that portrayed learners’ achievement as determined either by heredity or social contexts, the 12 learners constantly used their agentic possibilities to navigate constraining structural and cultural conditions at regional, familial and school levels to achieve academic success. Their agency was shaped by the socioeconomic conditions in their lives, namely, socioeconomic deprivation; large extended families in rural households, lack of amenities and utilities in their families, participation in household chores, experience of family tragedies and of changes when they were young.
- Full Text:
- Date Issued: 2018
BODIPY dyes for singlet oxygen and optical limiting applications
- Authors: Harris, Jessica
- Date: 2018
- Subjects: Photosensitizing compounds , Active oxygen -- Physiological effect , Photochemotherapy , Cancer -- Treatment , Nonlinear optics , BODIPY (Boron-dipyrromethene)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/58002 , vital:27014
- Description: A series of structurally related BODIPY dyes were synthesised and characterised. Their photophysical properties were studied in order to determine whether they would be suitable candidates for use as photosensitisers in the photodynamic therapy (PDT) treatment of cancer. The synthesis of two highly fluorescent BODIPY cores was achieved via the acid-catalysed condensation of a pyrrole and a functionalised aldehyde. In order to promote intersystem crossing, and hence improve the singlet oxygen generation of these dyes, bromine atoms were added at the 2,6-positions of the BODIPY core. These dibrominated analogues showed good singlet oxygen quantum yields, and excellent photostability in ethanol. In order to red-shift the main spectral bands of the BODIPY dyes towards the therapeutic window, vinyl/ styryl groups were introduced at the 3-, 5-, and 7-positions via a modified Knoevengal condensation reaction. The addition of vinyl/ styryl groups to the BODIPY core caused an increase in fluorescence quantum yield as well as a decrease in singlet oxygen quantum yield with respect to the dibrominated analogues. However, two of the red-shifted BODIPY dyes still showed moderate singlet oxygen quantum yields. The use of BODIPY dyes in nonlinear optics (NLO) was explored. The nonlinear optical characterisations and optical limiting properties of a series of 3,5-dithienylenevinylene BODIPY dyes were studied, both in dimethylformamide (DMF) solution and when embedded in poly(bisphenol A carbonate) (PBC) as thin films. The 3,5-dithienylenevinylene BODIPY dyes showed typical nonlinear absorption behaviour, with reverse saturable absorption (RSA) profiles, indicating that they have potential as optical limiters. The second-order hyperpolarizability (Y), and third-order nonlinear susceptibility (/m[/(3)]) values are also reported for these dyes. The optical limiting values of one of the BODIPY dyes in solution, and two of the BODIPY-embedded PBC films, were below the maximum threshold of 0.95 J-cm-2. The effect of addition of substituents on the electronic structure of the BODIPY dyes was investigated using TD-DFT calculations. The calculated trends closely followed those determined experimentally.
- Full Text:
- Date Issued: 2018
- Authors: Harris, Jessica
- Date: 2018
- Subjects: Photosensitizing compounds , Active oxygen -- Physiological effect , Photochemotherapy , Cancer -- Treatment , Nonlinear optics , BODIPY (Boron-dipyrromethene)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/58002 , vital:27014
- Description: A series of structurally related BODIPY dyes were synthesised and characterised. Their photophysical properties were studied in order to determine whether they would be suitable candidates for use as photosensitisers in the photodynamic therapy (PDT) treatment of cancer. The synthesis of two highly fluorescent BODIPY cores was achieved via the acid-catalysed condensation of a pyrrole and a functionalised aldehyde. In order to promote intersystem crossing, and hence improve the singlet oxygen generation of these dyes, bromine atoms were added at the 2,6-positions of the BODIPY core. These dibrominated analogues showed good singlet oxygen quantum yields, and excellent photostability in ethanol. In order to red-shift the main spectral bands of the BODIPY dyes towards the therapeutic window, vinyl/ styryl groups were introduced at the 3-, 5-, and 7-positions via a modified Knoevengal condensation reaction. The addition of vinyl/ styryl groups to the BODIPY core caused an increase in fluorescence quantum yield as well as a decrease in singlet oxygen quantum yield with respect to the dibrominated analogues. However, two of the red-shifted BODIPY dyes still showed moderate singlet oxygen quantum yields. The use of BODIPY dyes in nonlinear optics (NLO) was explored. The nonlinear optical characterisations and optical limiting properties of a series of 3,5-dithienylenevinylene BODIPY dyes were studied, both in dimethylformamide (DMF) solution and when embedded in poly(bisphenol A carbonate) (PBC) as thin films. The 3,5-dithienylenevinylene BODIPY dyes showed typical nonlinear absorption behaviour, with reverse saturable absorption (RSA) profiles, indicating that they have potential as optical limiters. The second-order hyperpolarizability (Y), and third-order nonlinear susceptibility (/m[/(3)]) values are also reported for these dyes. The optical limiting values of one of the BODIPY dyes in solution, and two of the BODIPY-embedded PBC films, were below the maximum threshold of 0.95 J-cm-2. The effect of addition of substituents on the electronic structure of the BODIPY dyes was investigated using TD-DFT calculations. The calculated trends closely followed those determined experimentally.
- Full Text:
- Date Issued: 2018
The impact of the cultural and creative industries on the economic growth and development of small cities and towns - guidelines for creating a regional cultural policy
- Authors: Ndhlovu, Raymond
- Date: 2018
- Subjects: Cultural industries -- South Africa , Cultural industries -- Economic aspects -- South Africa , Cultural policy , South Africa -- Economic conditions , Economic development -- South Africa -- Eastern Cape , South Africa. Department of Arts and Culture , Standard Bank National Arts Festival
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/61524 , vital:28032
- Description: The arts and cultural sector has come under even more financial strain than it previously was, as it has to compete with other sectors of the economy for the very limited public funding that is available. It is in this context that the economic impact, and the role, of the arts and cultural sector towards advancing economic growth and development, needs be examined. This thesis investigates the potential for the positive impact of the cultural and creative industries (CCIs) on growth and development of small cities and towns. Furthermore, it also provides guidelines for the development of regional cultural policy in small cities and towns. The CCIs have also been touted as a catalyst for economic growth and economic development, hence the global rise in their interest. For example, the CCIs have been used to redevelop and revive urban areas that have been rundown. CCIs, however, tend to develop in clusters, and additionally, they cluster around large cities. However, the lack of reliance of some CCIs on long supply chains or high-technology inputs may make them suitable candidates for investment in small cities and towns. Additionally, the link that small cities and towns have with rural and isolated areas makes them potential engines for driving growth, development, as well as employment creation for these areas, given their decline as a result of the transition from the traditional agricultural economy, to the knowledge economy. As CCIs have the propensity to drive government’s macroeconomic objectives such as efficiency, equity, economic growth and job creation, it is necessary to develop cultural policy that regards this. The tendency of CCIs to cluster and develop around large cities inevitably means that very little research into cultural policy directed towards regions without large cities and towns has been done. By the same token, very little research has also been conducted on how to craft cultural policy for such areas. In order then, for cultural policy for regions without large cities and towns to be developed, it is necessary to investigate, and provide, guidelines on, how to develop cultural policy for such regions. As a case study, the Sarah Baartman District Municipality (SBDM) in the Eastern Cape was chosen. The SBDM has no large cities and towns, but the District Municipality has identified the CCIs as a potential growth sector, and is in the process of developing a regional cultural policy. The area also includes Grahamstown, which not only hosts the National Arts Festival, which is the largest arts event of its type in Africa, but is also piloting the “Creative City” project in South Africa. An audit and mapping study was conducted on the CCIs in the SBDM; this was based on a national mapping study commissioned by the Department of Arts and Culture. Further internet searches, as well as consultations with the provincial and regional Department of Arts of Culture, coupled with snowball sampling, also aided in the identification of CCIs, and consequently, the “creative hotspots” within the SBDM. Two random samples of stakeholders were chosen; the CCI owners and practitioners, as well as key stakeholders such as government officials, and interviews conducted with both groups, in order to get a first-hand perspective on the operations, activities, challenges, and opportunities that are faced by the CCIs. The study found that there were at least 441 CCIs in the SBDM, with two local municipalities (Dr. Beyers Naude and Makana) hosting the largest share of these (145 and 113 CCIs in each local municipality respectively), which indicates some support for the ‘clustering’ theory. It was also found that the local municipalities that had the largest number of CCIs also experienced better socio-economic welfare. Furthermore, based on the UNESCO Framework for Cultural Statistics (FCS) domains, the Visual Arts and Crafts; Information, Books and Press; and, Cultural Heritage domains were the largest domains represented in the SBDM. It was concluded that cultural policy that is developed, ought to take advantage of, and build on, these existing clusters, as well as the domains that are most prevalent in the region. To demonstrate the impact of cultural festivals on growth and development, a socio-economic impact study was undertaken at the 2016 National Arts Festival (NAF) in Grahamstown. Face to interviews, as well as self-completion questionnaires were used, with respondents at different venues, attending a variety of shows, and across a range of demographics, being interviewed, in order to get a representative sample of Festival attendees. It was found that the economic impact of the 2016 NAF on the city of Grahamstown was R94.4 million. Over and above the economic value of the NAF, it was also found that there were nonmarket benefits (social and intrinsic values) of the NAF, that included audience development, education of the arts and culture, social cohesion, and community development. The inability to directly track and measure social and intrinsic values proved to be a challenge. The study concluded that in order for successful cultural policy to be developed in regions without large cities and towns, it is first necessary to carry out a study to identify what resources are present, and where they are. Locating resources enables cluster identification - as clusters encourage comparative and competitive advantage, it is worthwhile to invest in areas where there are clusters. Therefore, in the allocation of scarce public funds, cultural policy needs to guide investment in to areas where established clusters indicate existing comparative advantage. In terms of equity and transformation, it is also necessary to evaluate labour markets and ownership patterns when developing cultural policy. Beyond the analysis of physical and human resources, the study also found that a crucial step towards developing successful cultural policy is identification of opportunities and challenges faced by the practitioners themselves; the policy ought to capitalise on the opportunities, whilst attempting to correct the challenges faced. Also of importance is aligning the proposed policy and its objectives with regional, provincial and national aims and objectives. Finally, it is important to include a monitoring and evaluation tool that will evaluate the performance of the policy against its stated aims and objectives.
- Full Text:
- Date Issued: 2018
- Authors: Ndhlovu, Raymond
- Date: 2018
- Subjects: Cultural industries -- South Africa , Cultural industries -- Economic aspects -- South Africa , Cultural policy , South Africa -- Economic conditions , Economic development -- South Africa -- Eastern Cape , South Africa. Department of Arts and Culture , Standard Bank National Arts Festival
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/61524 , vital:28032
- Description: The arts and cultural sector has come under even more financial strain than it previously was, as it has to compete with other sectors of the economy for the very limited public funding that is available. It is in this context that the economic impact, and the role, of the arts and cultural sector towards advancing economic growth and development, needs be examined. This thesis investigates the potential for the positive impact of the cultural and creative industries (CCIs) on growth and development of small cities and towns. Furthermore, it also provides guidelines for the development of regional cultural policy in small cities and towns. The CCIs have also been touted as a catalyst for economic growth and economic development, hence the global rise in their interest. For example, the CCIs have been used to redevelop and revive urban areas that have been rundown. CCIs, however, tend to develop in clusters, and additionally, they cluster around large cities. However, the lack of reliance of some CCIs on long supply chains or high-technology inputs may make them suitable candidates for investment in small cities and towns. Additionally, the link that small cities and towns have with rural and isolated areas makes them potential engines for driving growth, development, as well as employment creation for these areas, given their decline as a result of the transition from the traditional agricultural economy, to the knowledge economy. As CCIs have the propensity to drive government’s macroeconomic objectives such as efficiency, equity, economic growth and job creation, it is necessary to develop cultural policy that regards this. The tendency of CCIs to cluster and develop around large cities inevitably means that very little research into cultural policy directed towards regions without large cities and towns has been done. By the same token, very little research has also been conducted on how to craft cultural policy for such areas. In order then, for cultural policy for regions without large cities and towns to be developed, it is necessary to investigate, and provide, guidelines on, how to develop cultural policy for such regions. As a case study, the Sarah Baartman District Municipality (SBDM) in the Eastern Cape was chosen. The SBDM has no large cities and towns, but the District Municipality has identified the CCIs as a potential growth sector, and is in the process of developing a regional cultural policy. The area also includes Grahamstown, which not only hosts the National Arts Festival, which is the largest arts event of its type in Africa, but is also piloting the “Creative City” project in South Africa. An audit and mapping study was conducted on the CCIs in the SBDM; this was based on a national mapping study commissioned by the Department of Arts and Culture. Further internet searches, as well as consultations with the provincial and regional Department of Arts of Culture, coupled with snowball sampling, also aided in the identification of CCIs, and consequently, the “creative hotspots” within the SBDM. Two random samples of stakeholders were chosen; the CCI owners and practitioners, as well as key stakeholders such as government officials, and interviews conducted with both groups, in order to get a first-hand perspective on the operations, activities, challenges, and opportunities that are faced by the CCIs. The study found that there were at least 441 CCIs in the SBDM, with two local municipalities (Dr. Beyers Naude and Makana) hosting the largest share of these (145 and 113 CCIs in each local municipality respectively), which indicates some support for the ‘clustering’ theory. It was also found that the local municipalities that had the largest number of CCIs also experienced better socio-economic welfare. Furthermore, based on the UNESCO Framework for Cultural Statistics (FCS) domains, the Visual Arts and Crafts; Information, Books and Press; and, Cultural Heritage domains were the largest domains represented in the SBDM. It was concluded that cultural policy that is developed, ought to take advantage of, and build on, these existing clusters, as well as the domains that are most prevalent in the region. To demonstrate the impact of cultural festivals on growth and development, a socio-economic impact study was undertaken at the 2016 National Arts Festival (NAF) in Grahamstown. Face to interviews, as well as self-completion questionnaires were used, with respondents at different venues, attending a variety of shows, and across a range of demographics, being interviewed, in order to get a representative sample of Festival attendees. It was found that the economic impact of the 2016 NAF on the city of Grahamstown was R94.4 million. Over and above the economic value of the NAF, it was also found that there were nonmarket benefits (social and intrinsic values) of the NAF, that included audience development, education of the arts and culture, social cohesion, and community development. The inability to directly track and measure social and intrinsic values proved to be a challenge. The study concluded that in order for successful cultural policy to be developed in regions without large cities and towns, it is first necessary to carry out a study to identify what resources are present, and where they are. Locating resources enables cluster identification - as clusters encourage comparative and competitive advantage, it is worthwhile to invest in areas where there are clusters. Therefore, in the allocation of scarce public funds, cultural policy needs to guide investment in to areas where established clusters indicate existing comparative advantage. In terms of equity and transformation, it is also necessary to evaluate labour markets and ownership patterns when developing cultural policy. Beyond the analysis of physical and human resources, the study also found that a crucial step towards developing successful cultural policy is identification of opportunities and challenges faced by the practitioners themselves; the policy ought to capitalise on the opportunities, whilst attempting to correct the challenges faced. Also of importance is aligning the proposed policy and its objectives with regional, provincial and national aims and objectives. Finally, it is important to include a monitoring and evaluation tool that will evaluate the performance of the policy against its stated aims and objectives.
- Full Text:
- Date Issued: 2018
Developing a citizen technician based approach to suspended sediment monitoring in the Tsitsa River catchment, Eastern Cape, South Africa
- Authors: Bannatyne, Laura Joan
- Date: 2018
- Subjects: Sediments (Geology) -- Management , Sediments (Geology) -- South Africa -- Eastern Cape , Watersheds -- South Africa -- Eastern Cape , Suspended sediments -- South Africa -- Eastern Cape , Suspended sediments -- Monitoring -- Citizen participation , Tsitsa River
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/62593 , vital:28211
- Description: Suspended sediment (SS) in channels is spatiotemporally heterogeneous and, over the long term, is known to be moved predominantly by flood flows with return periods of ~1 - 1.5 years. Flood flows in the Tsitsa catchment (Eastern Cape Province, South Africa) are unpredictable, and display a wide range of discharges. Direct, flood-focused SS sampling at sub-catchment scale was required to provide a SS baseline against which to monitor the impact on SS of catchment rehabilitation interventions, to determine the relative contributions of sub-catchments to SS loads and yields at the site of the proposed Ntabelanga Dam wall, and to verify modelled SS baselines, loads and yields. Approaches to SS sampling relying on researcher presence and/or installed equipment to adequately monitor SS through flood flows were precluded by cost, and the physical and socioeconomic conditions in the project area. A citizen technician (CT)-based flood-focused approach to direct SS sampling was developed and implemented. It was assessed in terms of its efficiency and effectiveness, the proficiency of the laboratory analysis methods, and the accuracy of the resulting SS data. A basic laboratory protocol for SSC analysis was developed, but is not the focus of this thesis. Using basic sampling equipment and smartphone-based reporting protocols, local residents at eleven points on the Tsitsa River and its major tributaries were employed as CTs. They were paid to take water samples during daylight hours at sub-daily timestep, with the emphasis on sampling through flood flows. The method was innovative in that it opted for manual sampling against a global trend towards instrumentation. Whilst the management of CTs formed a significant project component, the CTs benefitted directly through remuneration and work experience opportunities. The sampling method was evaluated at four sites from December 2015 - May 2016. The CTs were found to have efficiently and effectively sampled SS through a range of water levels, particularly in the main Tsitsa channel. An acceptable level of proficiency and accuracy was achieved, and many flood events were successfully defined by multiple data points. The method was chiefly limited by the inability of CTs to sample overnight rises and peaks occurring as a result of afternoon thunderstorms, particularly in small tributaries. The laboratory process was responsible for some losses in proficiency and accuracy. Improved laboratory quality control was therefore recommended. The CT-based approach can be adapted to other spatial and temporal scales in other areas, and to other environmental monitoring applications.
- Full Text:
- Date Issued: 2018
- Authors: Bannatyne, Laura Joan
- Date: 2018
- Subjects: Sediments (Geology) -- Management , Sediments (Geology) -- South Africa -- Eastern Cape , Watersheds -- South Africa -- Eastern Cape , Suspended sediments -- South Africa -- Eastern Cape , Suspended sediments -- Monitoring -- Citizen participation , Tsitsa River
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/62593 , vital:28211
- Description: Suspended sediment (SS) in channels is spatiotemporally heterogeneous and, over the long term, is known to be moved predominantly by flood flows with return periods of ~1 - 1.5 years. Flood flows in the Tsitsa catchment (Eastern Cape Province, South Africa) are unpredictable, and display a wide range of discharges. Direct, flood-focused SS sampling at sub-catchment scale was required to provide a SS baseline against which to monitor the impact on SS of catchment rehabilitation interventions, to determine the relative contributions of sub-catchments to SS loads and yields at the site of the proposed Ntabelanga Dam wall, and to verify modelled SS baselines, loads and yields. Approaches to SS sampling relying on researcher presence and/or installed equipment to adequately monitor SS through flood flows were precluded by cost, and the physical and socioeconomic conditions in the project area. A citizen technician (CT)-based flood-focused approach to direct SS sampling was developed and implemented. It was assessed in terms of its efficiency and effectiveness, the proficiency of the laboratory analysis methods, and the accuracy of the resulting SS data. A basic laboratory protocol for SSC analysis was developed, but is not the focus of this thesis. Using basic sampling equipment and smartphone-based reporting protocols, local residents at eleven points on the Tsitsa River and its major tributaries were employed as CTs. They were paid to take water samples during daylight hours at sub-daily timestep, with the emphasis on sampling through flood flows. The method was innovative in that it opted for manual sampling against a global trend towards instrumentation. Whilst the management of CTs formed a significant project component, the CTs benefitted directly through remuneration and work experience opportunities. The sampling method was evaluated at four sites from December 2015 - May 2016. The CTs were found to have efficiently and effectively sampled SS through a range of water levels, particularly in the main Tsitsa channel. An acceptable level of proficiency and accuracy was achieved, and many flood events were successfully defined by multiple data points. The method was chiefly limited by the inability of CTs to sample overnight rises and peaks occurring as a result of afternoon thunderstorms, particularly in small tributaries. The laboratory process was responsible for some losses in proficiency and accuracy. Improved laboratory quality control was therefore recommended. The CT-based approach can be adapted to other spatial and temporal scales in other areas, and to other environmental monitoring applications.
- Full Text:
- Date Issued: 2018