Semantic segmentation of astronomical radio images: a computer vision approach
- Authors: Kupa, Ramadimetse Sydil
- Date: 2023-03-29
- Subjects: Semantic segmentation , Radio astronomy , Radio telescopes , Deep learning (Machine learning) , Image segmentation
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422378 , vital:71937
- Description: The new generation of radio telescopes, such as the MeerKAT, ASKAP (Australian Square Kilometre Array Pathfinder) and the future Square Kilometre Array (SKA), are expected to produce vast amounts of data and images in the petabyte region. Therefore, the amount of incoming data at a specific point in time will overwhelm any current traditional data analysis method being deployed. Deep learning architectures have been applied in many fields, such as, in computer vision, machine vision, natural language processing, social network filtering, speech recognition, machine translation, bioinformatics, medical image analysis, and board game programs. They have produced results which are comparable to human expert performance. Hence, it is appealing to apply it to radio astronomy data. Image segmentation is one such area where deep learning techniques are prominent. The images from the new generation of telescopes have a high density of radio sources, making it difficult to classify the sources in the image. Identifying and segmenting sources from radio images is a pre-processing step that occurs before sources are put into different classes. There is thus a need for automatic segmentation of the sources from the images before they can be classified. This work uses the Unet architecture (originally developed for biomedical image segmentation) to segment radio sources from radio astronomical images with 99.8% accuracy. After segmenting the sources we use OpenCV tools to detect the sources on the mask images, then the detection is translated to the original image where borders are drawn around each detected source. This process automates and simplifies the pre-processing of images for classification tools and any other post-processing tool that requires a specific source as an input. , Thesis (MSc) -- Faculty of Science, Physics and Electronics, 2023
- Full Text:
- Date Issued: 2023-03-29
- Authors: Kupa, Ramadimetse Sydil
- Date: 2023-03-29
- Subjects: Semantic segmentation , Radio astronomy , Radio telescopes , Deep learning (Machine learning) , Image segmentation
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422378 , vital:71937
- Description: The new generation of radio telescopes, such as the MeerKAT, ASKAP (Australian Square Kilometre Array Pathfinder) and the future Square Kilometre Array (SKA), are expected to produce vast amounts of data and images in the petabyte region. Therefore, the amount of incoming data at a specific point in time will overwhelm any current traditional data analysis method being deployed. Deep learning architectures have been applied in many fields, such as, in computer vision, machine vision, natural language processing, social network filtering, speech recognition, machine translation, bioinformatics, medical image analysis, and board game programs. They have produced results which are comparable to human expert performance. Hence, it is appealing to apply it to radio astronomy data. Image segmentation is one such area where deep learning techniques are prominent. The images from the new generation of telescopes have a high density of radio sources, making it difficult to classify the sources in the image. Identifying and segmenting sources from radio images is a pre-processing step that occurs before sources are put into different classes. There is thus a need for automatic segmentation of the sources from the images before they can be classified. This work uses the Unet architecture (originally developed for biomedical image segmentation) to segment radio sources from radio astronomical images with 99.8% accuracy. After segmenting the sources we use OpenCV tools to detect the sources on the mask images, then the detection is translated to the original image where borders are drawn around each detected source. This process automates and simplifies the pre-processing of images for classification tools and any other post-processing tool that requires a specific source as an input. , Thesis (MSc) -- Faculty of Science, Physics and Electronics, 2023
- Full Text:
- Date Issued: 2023-03-29
A biography on inkosi Albert John Mvumbi Luthuli as an African intellectual
- Mngadi, Samkelo Ntobeko Vukani
- Authors: Mngadi, Samkelo Ntobeko Vukani
- Date: 2022-04-07
- Subjects: Luthuli, A J (Albert John), 1898-1967 , Luthuli, A J (Albert John), 1898-1967 Political and social views , Africans Intellectual life , South Africa History , South Africa Politics and government , African National Congress Biography , Apartheid South Africa , Political activists South Africa Biography , Intellectuals Political activity South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/294493 , vital:57226
- Description: [Excerpt taken from Introduction] The purpose of this study is to take a look at one of these African leaders, inkosi Albert Luthuli through a biographical lens to assess whether he should be recognised as an African intellectual. Sifiso Mxolisi Ndlovu states that inkosi Luthuli is recognised as the father of South Africa’s non-racialism. He used his moral authority in a historic fashion to influence the liberation movement to adopt non-violent resistance. During his time as President-General, he became the beacon of non-violent resistance. As the president of the liberation organisation, he delivered speeches that steered the African National Congress (ANC) and the liberation movement when the State escalated its oppression against Africans. The State retaliated by deposing him as an elected Chief, imprisoned him, imposed multiple bans on him in attempts to silence him. His intellect proved to be a threat to the State. He spoke out boldly against the apartheid state and advocated for chiefs, African people, African women, sugar farmers, and all oppressed racial groups. Inkosi Luthuli used his speeches to deliver political concepts like non-racialism, multiracialism, African nationalism and democracy into the public space. He cemented ANC’s cooperation policy that created the environment for the existence of the Congress Alliance that produced the Freedom Charter. He spoke out against the oppression of not just South Africans but Africa and all oppressed groups internationally. He illustrated that he possessed geopolitics that would gain the attention of the world. He illustrated his geopolitics through his internationalism philosophy gained the international community’s attention. Inkosi Luthuli was revered and respected by his Groutville community, the African community, South Africans of all racial groups and the international community. His impact can be seen through him being the first African-born Nobel Peace Prize recipient. He pushed for the international community to place economic sanctions and believed that international sanctions were the appropriate non-violent method the global community could get involved in fighting apartheid.5 The purpose of this study will be to explore how a Christian Zulu Chief’s intellectual thinking was able to move South Africa towards a multiracial democracy using non-violent resistance as a strategy to gain Africa and the world’s attention—looking at him from the vantage point of being an African intellectual. , Thesis (MA) -- Faculty of Humanities, History, 2022
- Full Text:
- Date Issued: 2022-04-07
- Authors: Mngadi, Samkelo Ntobeko Vukani
- Date: 2022-04-07
- Subjects: Luthuli, A J (Albert John), 1898-1967 , Luthuli, A J (Albert John), 1898-1967 Political and social views , Africans Intellectual life , South Africa History , South Africa Politics and government , African National Congress Biography , Apartheid South Africa , Political activists South Africa Biography , Intellectuals Political activity South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/294493 , vital:57226
- Description: [Excerpt taken from Introduction] The purpose of this study is to take a look at one of these African leaders, inkosi Albert Luthuli through a biographical lens to assess whether he should be recognised as an African intellectual. Sifiso Mxolisi Ndlovu states that inkosi Luthuli is recognised as the father of South Africa’s non-racialism. He used his moral authority in a historic fashion to influence the liberation movement to adopt non-violent resistance. During his time as President-General, he became the beacon of non-violent resistance. As the president of the liberation organisation, he delivered speeches that steered the African National Congress (ANC) and the liberation movement when the State escalated its oppression against Africans. The State retaliated by deposing him as an elected Chief, imprisoned him, imposed multiple bans on him in attempts to silence him. His intellect proved to be a threat to the State. He spoke out boldly against the apartheid state and advocated for chiefs, African people, African women, sugar farmers, and all oppressed racial groups. Inkosi Luthuli used his speeches to deliver political concepts like non-racialism, multiracialism, African nationalism and democracy into the public space. He cemented ANC’s cooperation policy that created the environment for the existence of the Congress Alliance that produced the Freedom Charter. He spoke out against the oppression of not just South Africans but Africa and all oppressed groups internationally. He illustrated that he possessed geopolitics that would gain the attention of the world. He illustrated his geopolitics through his internationalism philosophy gained the international community’s attention. Inkosi Luthuli was revered and respected by his Groutville community, the African community, South Africans of all racial groups and the international community. His impact can be seen through him being the first African-born Nobel Peace Prize recipient. He pushed for the international community to place economic sanctions and believed that international sanctions were the appropriate non-violent method the global community could get involved in fighting apartheid.5 The purpose of this study will be to explore how a Christian Zulu Chief’s intellectual thinking was able to move South Africa towards a multiracial democracy using non-violent resistance as a strategy to gain Africa and the world’s attention—looking at him from the vantage point of being an African intellectual. , Thesis (MA) -- Faculty of Humanities, History, 2022
- Full Text:
- Date Issued: 2022-04-07
A decision-making model to guide securing blockchain deployments
- Authors: Cronje, Gerhard Roets
- Date: 2021-10-29
- Subjects: Blockchains (Databases) , Bitcoin , Cryptocurrencies , Distributed databases , Computer networks Security measures , Computer networks Security measures Decision making , Ethereum
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188865 , vital:44793
- Description: Satoshi Nakamoto, the pseudo-identity accredit with the paper that sparked the implementation of Bitcoin, is famously quoted as remarking, electronically of course, that “If you don’t believe it or don’t get it, I don’t have time to try and convince you, sorry” (Tsapis, 2019, p. 1). What is noticeable, 12 years after the famed Satoshi paper that initiated Bitcoin (Nakamoto, 2008), is that blockchain at the very least has staying power and potentially wide application. A lesser known figure Marc Kenisberg, founder of Bitcoin Chaser which is one of the many companies formed around the Bitcoin ecosystem, summarised it well saying “…Blockchain is the tech - Bitcoin is merely the first mainstream manifestation of its potential” (Tsapis, 2019, p. 1). With blockchain still trying to reach its potential and still maturing on its way towards a mainstream technology the main question that arises for security professionals is how do I ensure we do it securely? This research seeks to address that question by proposing a decision-making model that can be used by a security professional to guide them through ensuring appropriate security for blockchain deployments. This research is certainly not the first attempt at discussing the security of the blockchain and will not be the last, as the technology around blockchain and distributed ledger technology is still rapidly evolving. What this research does try to achieve is not to delve into extremely specific areas of blockchain security, or get bogged down in technical details, but to provide a reference framework that aims to cover all the major areas to be considered. The approach followed was to review the literature regarding blockchain and to identify the main security areas to be addressed. It then proposes a decision-making model and tests the model against a fictitious but relevant real-world example. It concludes with learnings from this research. The reader can be the judge, but the model aims to be a practical valuable resource to be used by any security professional, to navigate the security aspects logically and understandably when being involved in a blockchain deployment. In contrast to the Satoshi quote, this research tries to convince the reader and assist him/her in understanding the security choices related to every blockchain deployment. , Thesis (MSc) -- Faculty of Science, Computer Science, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Cronje, Gerhard Roets
- Date: 2021-10-29
- Subjects: Blockchains (Databases) , Bitcoin , Cryptocurrencies , Distributed databases , Computer networks Security measures , Computer networks Security measures Decision making , Ethereum
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188865 , vital:44793
- Description: Satoshi Nakamoto, the pseudo-identity accredit with the paper that sparked the implementation of Bitcoin, is famously quoted as remarking, electronically of course, that “If you don’t believe it or don’t get it, I don’t have time to try and convince you, sorry” (Tsapis, 2019, p. 1). What is noticeable, 12 years after the famed Satoshi paper that initiated Bitcoin (Nakamoto, 2008), is that blockchain at the very least has staying power and potentially wide application. A lesser known figure Marc Kenisberg, founder of Bitcoin Chaser which is one of the many companies formed around the Bitcoin ecosystem, summarised it well saying “…Blockchain is the tech - Bitcoin is merely the first mainstream manifestation of its potential” (Tsapis, 2019, p. 1). With blockchain still trying to reach its potential and still maturing on its way towards a mainstream technology the main question that arises for security professionals is how do I ensure we do it securely? This research seeks to address that question by proposing a decision-making model that can be used by a security professional to guide them through ensuring appropriate security for blockchain deployments. This research is certainly not the first attempt at discussing the security of the blockchain and will not be the last, as the technology around blockchain and distributed ledger technology is still rapidly evolving. What this research does try to achieve is not to delve into extremely specific areas of blockchain security, or get bogged down in technical details, but to provide a reference framework that aims to cover all the major areas to be considered. The approach followed was to review the literature regarding blockchain and to identify the main security areas to be addressed. It then proposes a decision-making model and tests the model against a fictitious but relevant real-world example. It concludes with learnings from this research. The reader can be the judge, but the model aims to be a practical valuable resource to be used by any security professional, to navigate the security aspects logically and understandably when being involved in a blockchain deployment. In contrast to the Satoshi quote, this research tries to convince the reader and assist him/her in understanding the security choices related to every blockchain deployment. , Thesis (MSc) -- Faculty of Science, Computer Science, 2021
- Full Text:
- Date Issued: 2021-10-29
An interpretation of the deeming provisions in legislation in the context of a good tax system: a South African perspective
- Authors: Mostert, Tarita
- Date: 2021-10-29
- Subjects: Organisation for Economic Co-operation and Development , Taxation Law and legislation South Africa , South Africa. Income Tax Act, 1962 , Taxpayer compliance South Africa , Tax evasion (International law) , Deeming provisions
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/190897 , vital:45039 , 10.21504/10962/190897
- Description: The goal of this thesis is to analyse the relationship between deeming provisions in legislation and the principles of a good tax system. The need for a positive relationship between deeming provisions and the principles of a good tax system is demonstrated in the thesis. The research explains the historical development of deeming provisions, legal principles relevant to the interpretation of tax legislation, as well as the principles of a good tax system. Approaches to the interpretation of legislation are then described and illustrated by means of case law. Following this, the research focuses on a selection of provisions in the South African Income Tax Act, 58 of 1962, to determine whether the deeming provisions included in the Act reflect the application of the principles of a good tax system. In addition to the analysis of the selected statutory provisions, related case law is discussed, again in relation to the deeming provisions. A discussion of deeming provisions in two publications of the Organisation for Economic Co-Operation and Development (OECD) – the OECD Model Tax Convention and the OECD Multilateral Convention to Implement Tax Treaty Measures to Prevent Base Erosion and Profit Shifting – follows, with an analysis of two related deeming provisions in the Income Tax Act, to illustrate the international approach to deeming provisions and the principles of a good tax system. Finally, the administration of tax legislation is discussed, together with organisations whose mission is to promote the principles of a good tax system in tax administration. The research is qualitative in nature and follows a legal doctrinal research methodology. This methodology is both reform-oriented and theoretical and focuses on understanding the application of the legal concepts: deeming provisions, legal principles and principles of a good tax system. The research concludes that, from a theoretical perspective, a positive relationship exists between deeming provisions in the Income Tax Act and the OECD Model Tax Convention and the principles of a good tax system, and therefore creates a positive environment for tax compliance. , Thesis (PhD) -- Faculty of Commerce, Accounting, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Mostert, Tarita
- Date: 2021-10-29
- Subjects: Organisation for Economic Co-operation and Development , Taxation Law and legislation South Africa , South Africa. Income Tax Act, 1962 , Taxpayer compliance South Africa , Tax evasion (International law) , Deeming provisions
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/190897 , vital:45039 , 10.21504/10962/190897
- Description: The goal of this thesis is to analyse the relationship between deeming provisions in legislation and the principles of a good tax system. The need for a positive relationship between deeming provisions and the principles of a good tax system is demonstrated in the thesis. The research explains the historical development of deeming provisions, legal principles relevant to the interpretation of tax legislation, as well as the principles of a good tax system. Approaches to the interpretation of legislation are then described and illustrated by means of case law. Following this, the research focuses on a selection of provisions in the South African Income Tax Act, 58 of 1962, to determine whether the deeming provisions included in the Act reflect the application of the principles of a good tax system. In addition to the analysis of the selected statutory provisions, related case law is discussed, again in relation to the deeming provisions. A discussion of deeming provisions in two publications of the Organisation for Economic Co-Operation and Development (OECD) – the OECD Model Tax Convention and the OECD Multilateral Convention to Implement Tax Treaty Measures to Prevent Base Erosion and Profit Shifting – follows, with an analysis of two related deeming provisions in the Income Tax Act, to illustrate the international approach to deeming provisions and the principles of a good tax system. Finally, the administration of tax legislation is discussed, together with organisations whose mission is to promote the principles of a good tax system in tax administration. The research is qualitative in nature and follows a legal doctrinal research methodology. This methodology is both reform-oriented and theoretical and focuses on understanding the application of the legal concepts: deeming provisions, legal principles and principles of a good tax system. The research concludes that, from a theoretical perspective, a positive relationship exists between deeming provisions in the Income Tax Act and the OECD Model Tax Convention and the principles of a good tax system, and therefore creates a positive environment for tax compliance. , Thesis (PhD) -- Faculty of Commerce, Accounting, 2021
- Full Text:
- Date Issued: 2021-10-29
Establishing a water resources assessment system for Eswatini (Swaziland) incorporating data and modelling uncertainty
- Authors: Ndzabandzaba, Coli
- Date: 2021-10-29
- Subjects: Water resources development Eswatini , Water-supply Eswatini Management , Hydrologic models Eswatini , Runoff Mathematical models , Rain and rainfall Mathematical models , Pitman model
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/189009 , vital:44806 , 10.21504/10962/189009
- Description: The uneven distribution of water resources availability globally puts pressure on environmental and human or socio-economic systems and has complex implications for the interactions within these systems. The natural environment and water resources are increasingly threatened by development, and water management crises are still occurring. This is exacerbated by the lack of accurate and adequate information on these systems. In Eswatini, for example, the pressure on the available water resources is mounting due to increasing water demand for irrigation while information about natural hydrological conditions and levels of water resources developments are uncertain. In addition, the practical application of hydrological models for water resources assessments that incorporate uncertainty in Eswatini has yet to be realised. The aim of the study, therefore, was to develop a water resource assessment system that is based on both observed and simulated information and that includes uncertainty. This study focusses on a regional water resource assessment using an uncertainty version of the Pitman monthly rainfall-runoff model whose outputs are constrained by six indices of natural hydrological response (i.e., mean monthly runoff, mean monthly groundwater recharge, Q10, Q50 and Q90 percentage points of the flow duration curve and % time of zero flows) for each of the 122 sub-basins of the transboundary catchments of Eswatini. A 2-step uncertainty modelling approach was tested, validated and then applied to all the sub-basins of Eswatini. The first step of the model run establishes behavioural, but uncertain model parameter ranges for natural incremental sub-basin hydrological responses and the model is typically run 100 000 times for each sub-basin. The parameter space that defines the uncertainty in parameter estimation is sampled based on simple Monte Carlo approach. The second step links all the sub-basin outputs and allows for water use parameters to be incorporated, where necessary, in order to generate cumulative sub-basin outflows. The results from the constraint index analysis have proved to be useful in constraining the model outputs. Generally, the behavioural model outputs produced realistic uncertainty estimates as well as acceptable simulations based on the assessment of the flow duration curves. The modelling results indicated that there is some degree of uncertainty that cannot be easily accounted for due to some identified data issues. The results also showed that there is still a possibility to improve the simulations provided such issues are resolved. The issues about the simulation of stream flow that were detected are mainly related to availability of data to estimate water use parameters. Another challenge in setting up the model was associated with establishing constraints that match the parameters for natural hydrological conditions for specific sub-basins and maintaining consistency in the adjustment of the model output constraints for other sub-basins. In an attempt to overcome this problem, the study recommends additional hydrological response constraints to be used with the Pitman model. Another main recommendation relates to the strong cooperation of relevant catchment management authorities and stakeholders including scientists in order to make information more available to users. The new hydrological insight is derived from the analysis of hydrological indices which highlighted the regional variations in hydrological processes and sub-basin response across the transboundary basins of Eswatini. The adopted modelling approach provides further insight into all the uncertainties associated with quantifying the available water resources of the country. The study has provided further understanding of the spatial variability of the hydrological response and existing development impacts than was previously available. It is envisaged that these new insights will provide an improved basis for future water management in Eswatini. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Ndzabandzaba, Coli
- Date: 2021-10-29
- Subjects: Water resources development Eswatini , Water-supply Eswatini Management , Hydrologic models Eswatini , Runoff Mathematical models , Rain and rainfall Mathematical models , Pitman model
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/189009 , vital:44806 , 10.21504/10962/189009
- Description: The uneven distribution of water resources availability globally puts pressure on environmental and human or socio-economic systems and has complex implications for the interactions within these systems. The natural environment and water resources are increasingly threatened by development, and water management crises are still occurring. This is exacerbated by the lack of accurate and adequate information on these systems. In Eswatini, for example, the pressure on the available water resources is mounting due to increasing water demand for irrigation while information about natural hydrological conditions and levels of water resources developments are uncertain. In addition, the practical application of hydrological models for water resources assessments that incorporate uncertainty in Eswatini has yet to be realised. The aim of the study, therefore, was to develop a water resource assessment system that is based on both observed and simulated information and that includes uncertainty. This study focusses on a regional water resource assessment using an uncertainty version of the Pitman monthly rainfall-runoff model whose outputs are constrained by six indices of natural hydrological response (i.e., mean monthly runoff, mean monthly groundwater recharge, Q10, Q50 and Q90 percentage points of the flow duration curve and % time of zero flows) for each of the 122 sub-basins of the transboundary catchments of Eswatini. A 2-step uncertainty modelling approach was tested, validated and then applied to all the sub-basins of Eswatini. The first step of the model run establishes behavioural, but uncertain model parameter ranges for natural incremental sub-basin hydrological responses and the model is typically run 100 000 times for each sub-basin. The parameter space that defines the uncertainty in parameter estimation is sampled based on simple Monte Carlo approach. The second step links all the sub-basin outputs and allows for water use parameters to be incorporated, where necessary, in order to generate cumulative sub-basin outflows. The results from the constraint index analysis have proved to be useful in constraining the model outputs. Generally, the behavioural model outputs produced realistic uncertainty estimates as well as acceptable simulations based on the assessment of the flow duration curves. The modelling results indicated that there is some degree of uncertainty that cannot be easily accounted for due to some identified data issues. The results also showed that there is still a possibility to improve the simulations provided such issues are resolved. The issues about the simulation of stream flow that were detected are mainly related to availability of data to estimate water use parameters. Another challenge in setting up the model was associated with establishing constraints that match the parameters for natural hydrological conditions for specific sub-basins and maintaining consistency in the adjustment of the model output constraints for other sub-basins. In an attempt to overcome this problem, the study recommends additional hydrological response constraints to be used with the Pitman model. Another main recommendation relates to the strong cooperation of relevant catchment management authorities and stakeholders including scientists in order to make information more available to users. The new hydrological insight is derived from the analysis of hydrological indices which highlighted the regional variations in hydrological processes and sub-basin response across the transboundary basins of Eswatini. The adopted modelling approach provides further insight into all the uncertainties associated with quantifying the available water resources of the country. The study has provided further understanding of the spatial variability of the hydrological response and existing development impacts than was previously available. It is envisaged that these new insights will provide an improved basis for future water management in Eswatini. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2021
- Full Text:
- Date Issued: 2021-10-29
Integrative systematic structuring of the widespread psammophiid snakes (Psammophiidae): a multi-evidence species delineation approach
- Authors: Keates, Chad
- Date: 2021-10-29
- Subjects: Psammophis South Africa , Herpetology , Herpetology Africa , Molecular biology , Psammophis Classification , Psammophis Genetics , Psammophis Morphology , Psammophis Phylogeny , Morphology Mathematics , Psammophylax
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/295077 , vital:57288 , DOI 10.21504/10962/295079
- Description: Species form the foundations upon which we build our understanding of the natural world. Although a focus of much scientific attention, our understanding of species is stunted by the intrinsic ‘fuzziness’ of boundaries within nature. Due to the complexity of the evolutionary process, coupled with an ever-changing abiotic landscape, species are hard to delineate, even at the best of times. Whilst various species concepts and sophisticated delimitation methods have helped scientists tease apart species, many species complexes persist. This is because taxonomy is a discrete ordering system imposed upon the continuous and intercalated structure of life. To improve our understanding of a wide-ranging family of snakes, I investigated the taxonomy and evolutionary structuring within Psammophiidae using both molecular and morphological approaches, employing phylogenetic, phylogeographic, and morphometric analyses on the group. The systematic complexity of the family (as evidenced by past research) coupled with the group’s widespread distribution and ecological importance, made the taxon an ideal candidate for a broad-sweeping multi-level systematic analysis using multiple species delimitation methods. Additionally, in this thesis I attempted to build on the ground-breaking work of Christopher Kelly by addressing several knowledge gaps identified within the family, and in so doing, produce the most thorough evolutionary and taxonomic study of Psammophiidae possible. Given the taxonomic uncertainty associated with the family, Chapter Two used a representative sampling from every available species (near complete taxon sampling approach) in the family. The chapter used both standard and time-calibrated phylogenetic modelling and distance/threshold-based species delimitation, to elucidate the finer-level structuring within the family. Geometric morphometrics was used to determine whether there were diagnosable differences in head structure between the different genera. The final phylogenetic tree incorporated 320 samples, representing the most comprehensive phylogenetic reconstruction of the family to date. By using a near-complete taxon sampling approach, I was able to resolve previously unsupported relationships within the family whilst also identifying several novel instances of an under- and over-appreciation of species diversity within the family. Geometric morphometrics also identified clear distinctions between genera based on head shape (head width and ‘beakedness’). This chapter showcased the importance of complete taxon sampling and robust methodology for species delimitation and the deleterious effect of species concepts when implemented in isolation. In Chapter Three, I narrowed the scope of the study to focus on the genus level. Psammophylax (Fitzinger 1843) is an abundant, yet poorly studied genus of grass snakes, endemic to Africa. The generalist nature of the genus and wide-spanning distributions of the constituent species has given rise to several subspecies and a poor understanding of the taxonomic structuring within the genus. The overlapping distributions (sympatry) of many of Psammophylax species, coupled with the potential for cryptic speciation via mechanisms such as convergent evolution, made the group the ideal candidate for a broad-sweeping systematic study (as evidenced in Chapter Two). By applying the suite of analyses used in Chapter Two to the generic level, we aimed to determine the effectiveness of a multi-evidence species delineation approach when tackling systematic problems at lower taxonomic levels. A genetic phylogeny of six of the seven species was estimated using multiple phylogenetic and distance/ threshold-based species delimitation methods. To support the molecular analyses, we conducted morphological analyses on the body (traditional morphology) and head (geometric morphometrics) separately. Phylogenetic analyses recovered a similar topology to past studies, but with better resolution and node support. I found substantial genetic structuring within the genus, supported by significantly different head shapes between Ps. a. acutus and other Psammophylax species. Psammophylax a. acutus was recovered as sister to its congeners, and sequence divergence values and morphometrics supported its recognition as a new genus. Increased sampling in East Africa (Tanzania, Kenya, and Ethiopia) revealed that Psammophylax multisquamis is polyphyletic, necessitating the description of a new, morphologically cryptic, species from northern Tanzania. The distribution of Ps. multisquamis sensu stricto is likely restricted to Kenya and Ethiopia. Within this chapter, taxon-specific phylogenetic analyses yielded stronger intrageneric support as compared to Chapter Two, allowing for more defensible conclusions about taxonomical amendments. Geometric morphometrics proved similarly useful (as compared to Chapter Two) in teasing apart genera within the family but lacked the robustness to delineate species within Psammophylax with confidence, highlighting the apparent convergence of form within the genus. In Chapter Four, I investigated the evolutionary structuring within the Southern African endemic Psammophylax rhombeatus. The structural and environmental heterogeneity within the region has given rise to many morphological forms distributed throughout the country, with previous studies neglecting the associated molecular significance of these forms. Irrespective of their small sample sizes, both Chapter Two and Three identified substantial phylogenetic structuring within the species, making Ps. rhombeatus the ideal candidate for a multi-faceted systematic review, using a combination of phylogenetics, geometric morphometrics and, for the first time in this species, phylogeographic analyses. By investigating a single species, in detail, I was able to assess the effectiveness of the methodologies implemented in previous chapters on systematic sorting using the multi-evidence species delineation approach. Phylogenetic and haplotype analysis retrieved four well-supported clades: southeast South Africa (SESA), southwest South Africa (SWSA), north-eastern South Africa (NESA) and western South Africa (WSA). Although not variable enough to warrant taxonomic re-evaluation, the clades represented important genetic hotspots, with relatively high intraspecific genetic divergence values separating them, irrespective of the small geographic distances separating populations. This is likely a product of the taxon’s habitat-generalist lifestyle, enabling them to bypass vicariant barriers that might otherwise cause speciation in less versatile species. The clades are also geographically distinct, with little overlap, indicating previous vicariance, a finding that is supported by the split of Ps. rhombeatus from Ps. ocellatus in the mid-Pliocene, followed by the diversification of Ps. rhombeatus into four clades throughout the Pleistocene. The genetic structuring observed in Ps. rhombeatus may be a product of population expansion following ancient refugial isolation (potentially Last Glacial Maximum [LGM]). The molecular distinctiveness of the clades was not replicated in the morphological component of this chapter, with neither dorsal nor lateral geometric morphometric analyses of head shape showing any discernible distinctiveness based on geography. Whilst head shape has not been shown to be an effective delineator of evolutionary units at the species level (within this taxon), body colour, scalation, and snout-vent length has been linked to morphotypes within the species based on the work of Broadley (1966). These morphological groupings are loosely attributable to the molecular clades identified in the phylogenetic analyses, highlighting the complex interplay of genetic and morphological characteristics in the process of speciation, and their representation in systematic accounts. This thesis represents the most thorough evolutionary and systematic study of the family currently possible. In addition to identifying and describing both a new genus and species, this thesis also highlighted several instances of an over- and under-appreciation of species diversity within Psammophiidae. By applying a multi-evidence species delineation approach to this thesis, I show the intricacy of the evolutionary process (at various taxonomic levels) and showcase the ease to which species boundaries can be confounded when species concepts are implemented in isolation. These findings also highlighted the importance of sample size, sample range, species delimitation method on the outcome of taxonomic analyses, and their interpretation. Lastly, this thesis addressed the knowledge gaps left by Christopher Kelly’s PhD work and investigated the findings of recent papers that attempted to do the same. Whilst this study answers the questions of old, the taxon-intensive focus revealed several new knowledge gaps within the family, highlighting how much we know about snake systematics, and furthermore, how much we still need to learn about evolutionary structuring. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Keates, Chad
- Date: 2021-10-29
- Subjects: Psammophis South Africa , Herpetology , Herpetology Africa , Molecular biology , Psammophis Classification , Psammophis Genetics , Psammophis Morphology , Psammophis Phylogeny , Morphology Mathematics , Psammophylax
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/295077 , vital:57288 , DOI 10.21504/10962/295079
- Description: Species form the foundations upon which we build our understanding of the natural world. Although a focus of much scientific attention, our understanding of species is stunted by the intrinsic ‘fuzziness’ of boundaries within nature. Due to the complexity of the evolutionary process, coupled with an ever-changing abiotic landscape, species are hard to delineate, even at the best of times. Whilst various species concepts and sophisticated delimitation methods have helped scientists tease apart species, many species complexes persist. This is because taxonomy is a discrete ordering system imposed upon the continuous and intercalated structure of life. To improve our understanding of a wide-ranging family of snakes, I investigated the taxonomy and evolutionary structuring within Psammophiidae using both molecular and morphological approaches, employing phylogenetic, phylogeographic, and morphometric analyses on the group. The systematic complexity of the family (as evidenced by past research) coupled with the group’s widespread distribution and ecological importance, made the taxon an ideal candidate for a broad-sweeping multi-level systematic analysis using multiple species delimitation methods. Additionally, in this thesis I attempted to build on the ground-breaking work of Christopher Kelly by addressing several knowledge gaps identified within the family, and in so doing, produce the most thorough evolutionary and taxonomic study of Psammophiidae possible. Given the taxonomic uncertainty associated with the family, Chapter Two used a representative sampling from every available species (near complete taxon sampling approach) in the family. The chapter used both standard and time-calibrated phylogenetic modelling and distance/threshold-based species delimitation, to elucidate the finer-level structuring within the family. Geometric morphometrics was used to determine whether there were diagnosable differences in head structure between the different genera. The final phylogenetic tree incorporated 320 samples, representing the most comprehensive phylogenetic reconstruction of the family to date. By using a near-complete taxon sampling approach, I was able to resolve previously unsupported relationships within the family whilst also identifying several novel instances of an under- and over-appreciation of species diversity within the family. Geometric morphometrics also identified clear distinctions between genera based on head shape (head width and ‘beakedness’). This chapter showcased the importance of complete taxon sampling and robust methodology for species delimitation and the deleterious effect of species concepts when implemented in isolation. In Chapter Three, I narrowed the scope of the study to focus on the genus level. Psammophylax (Fitzinger 1843) is an abundant, yet poorly studied genus of grass snakes, endemic to Africa. The generalist nature of the genus and wide-spanning distributions of the constituent species has given rise to several subspecies and a poor understanding of the taxonomic structuring within the genus. The overlapping distributions (sympatry) of many of Psammophylax species, coupled with the potential for cryptic speciation via mechanisms such as convergent evolution, made the group the ideal candidate for a broad-sweeping systematic study (as evidenced in Chapter Two). By applying the suite of analyses used in Chapter Two to the generic level, we aimed to determine the effectiveness of a multi-evidence species delineation approach when tackling systematic problems at lower taxonomic levels. A genetic phylogeny of six of the seven species was estimated using multiple phylogenetic and distance/ threshold-based species delimitation methods. To support the molecular analyses, we conducted morphological analyses on the body (traditional morphology) and head (geometric morphometrics) separately. Phylogenetic analyses recovered a similar topology to past studies, but with better resolution and node support. I found substantial genetic structuring within the genus, supported by significantly different head shapes between Ps. a. acutus and other Psammophylax species. Psammophylax a. acutus was recovered as sister to its congeners, and sequence divergence values and morphometrics supported its recognition as a new genus. Increased sampling in East Africa (Tanzania, Kenya, and Ethiopia) revealed that Psammophylax multisquamis is polyphyletic, necessitating the description of a new, morphologically cryptic, species from northern Tanzania. The distribution of Ps. multisquamis sensu stricto is likely restricted to Kenya and Ethiopia. Within this chapter, taxon-specific phylogenetic analyses yielded stronger intrageneric support as compared to Chapter Two, allowing for more defensible conclusions about taxonomical amendments. Geometric morphometrics proved similarly useful (as compared to Chapter Two) in teasing apart genera within the family but lacked the robustness to delineate species within Psammophylax with confidence, highlighting the apparent convergence of form within the genus. In Chapter Four, I investigated the evolutionary structuring within the Southern African endemic Psammophylax rhombeatus. The structural and environmental heterogeneity within the region has given rise to many morphological forms distributed throughout the country, with previous studies neglecting the associated molecular significance of these forms. Irrespective of their small sample sizes, both Chapter Two and Three identified substantial phylogenetic structuring within the species, making Ps. rhombeatus the ideal candidate for a multi-faceted systematic review, using a combination of phylogenetics, geometric morphometrics and, for the first time in this species, phylogeographic analyses. By investigating a single species, in detail, I was able to assess the effectiveness of the methodologies implemented in previous chapters on systematic sorting using the multi-evidence species delineation approach. Phylogenetic and haplotype analysis retrieved four well-supported clades: southeast South Africa (SESA), southwest South Africa (SWSA), north-eastern South Africa (NESA) and western South Africa (WSA). Although not variable enough to warrant taxonomic re-evaluation, the clades represented important genetic hotspots, with relatively high intraspecific genetic divergence values separating them, irrespective of the small geographic distances separating populations. This is likely a product of the taxon’s habitat-generalist lifestyle, enabling them to bypass vicariant barriers that might otherwise cause speciation in less versatile species. The clades are also geographically distinct, with little overlap, indicating previous vicariance, a finding that is supported by the split of Ps. rhombeatus from Ps. ocellatus in the mid-Pliocene, followed by the diversification of Ps. rhombeatus into four clades throughout the Pleistocene. The genetic structuring observed in Ps. rhombeatus may be a product of population expansion following ancient refugial isolation (potentially Last Glacial Maximum [LGM]). The molecular distinctiveness of the clades was not replicated in the morphological component of this chapter, with neither dorsal nor lateral geometric morphometric analyses of head shape showing any discernible distinctiveness based on geography. Whilst head shape has not been shown to be an effective delineator of evolutionary units at the species level (within this taxon), body colour, scalation, and snout-vent length has been linked to morphotypes within the species based on the work of Broadley (1966). These morphological groupings are loosely attributable to the molecular clades identified in the phylogenetic analyses, highlighting the complex interplay of genetic and morphological characteristics in the process of speciation, and their representation in systematic accounts. This thesis represents the most thorough evolutionary and systematic study of the family currently possible. In addition to identifying and describing both a new genus and species, this thesis also highlighted several instances of an over- and under-appreciation of species diversity within Psammophiidae. By applying a multi-evidence species delineation approach to this thesis, I show the intricacy of the evolutionary process (at various taxonomic levels) and showcase the ease to which species boundaries can be confounded when species concepts are implemented in isolation. These findings also highlighted the importance of sample size, sample range, species delimitation method on the outcome of taxonomic analyses, and their interpretation. Lastly, this thesis addressed the knowledge gaps left by Christopher Kelly’s PhD work and investigated the findings of recent papers that attempted to do the same. Whilst this study answers the questions of old, the taxon-intensive focus revealed several new knowledge gaps within the family, highlighting how much we know about snake systematics, and furthermore, how much we still need to learn about evolutionary structuring. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2021
- Full Text:
- Date Issued: 2021-10-29
Synthesis, characterization and antiparasitic evaluation of chalcone hybrids
- Authors: Zulu, Ayanda Ignatia
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192853 , vital:45271
- Description: Thesis (PhD) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Zulu, Ayanda Ignatia
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192853 , vital:45271
- Description: Thesis (PhD) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10-29
Phylogeography and reproductive isolation of the brown mussel, Perna perna, on the South African coastline
- Authors: Barker, Cassandra
- Date: 2021-10
- Subjects: Mexilhao mussel South Africa , Phylogeography South Africa , Mexilhao mussel Reproduction , Mexilhao mussel Genetics , Intertidal organisms South Africa , Mexilhao mussel Climatic factors South Africa , Cytochrome oxidase , Mitochondrial DNA , Haplotype network
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190041 , vital:44958
- Description: Maintenance of a species’ abundance and adaptive potential is partially dependent on its genetic diversity. Distinct genetic lineages within a species can differ significantly in their resistance and resilience to environmental pressure. An assessment of such differences is key to grasp the adaptive potential of a species. Physical environmental conditions are significant determinants of the distribution of species and their genetic lineages. Under climate change scenarios, the assessment of the temporal stability of the spatial distribution of genetic structure has important consequences for conservation as it offers key insights into the adaptive potential and evolutionary capacity of a species. This thesis investigated the phylogeography and reproductive isolation of Perna perna, the brown mussel. This species is an ecologically and economically important intertidal mussel on South Africa’s coastline. It was determined in 2007 that there were two distinct genetic lineages of P. perna present on South Africa’s coastline, the Eastern and Western lineage. This thesis compared mitochondrial DNA between samples collected in 2007 and samples collected in 2019 to determine differences in genetic structure of P. perna over time. This thesis further investigated the reproductive timing of the two lineages to determine if this contributes to the maintenance of the genetic structure of this species. The results show that there is a shift in the distribution of the Eastern lineage since 2007, an increase in the range of the overlap region, and there was a change in genetic diversity in the form of private haplotypes between 2007 and 2019. The lineages have unsynchronised spawning and reproductive patterns are more closely linked to changes in temperature. While the lineages have shown slight distributional changes over time, the influence of environmental conditions and the predicted changes in sea surface temperatures could see a change in future populations’ fitness and dispersal. Thus, changes in sea surface temperature could affect reproductive timing and the future genetic stability of the species. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Barker, Cassandra
- Date: 2021-10
- Subjects: Mexilhao mussel South Africa , Phylogeography South Africa , Mexilhao mussel Reproduction , Mexilhao mussel Genetics , Intertidal organisms South Africa , Mexilhao mussel Climatic factors South Africa , Cytochrome oxidase , Mitochondrial DNA , Haplotype network
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190041 , vital:44958
- Description: Maintenance of a species’ abundance and adaptive potential is partially dependent on its genetic diversity. Distinct genetic lineages within a species can differ significantly in their resistance and resilience to environmental pressure. An assessment of such differences is key to grasp the adaptive potential of a species. Physical environmental conditions are significant determinants of the distribution of species and their genetic lineages. Under climate change scenarios, the assessment of the temporal stability of the spatial distribution of genetic structure has important consequences for conservation as it offers key insights into the adaptive potential and evolutionary capacity of a species. This thesis investigated the phylogeography and reproductive isolation of Perna perna, the brown mussel. This species is an ecologically and economically important intertidal mussel on South Africa’s coastline. It was determined in 2007 that there were two distinct genetic lineages of P. perna present on South Africa’s coastline, the Eastern and Western lineage. This thesis compared mitochondrial DNA between samples collected in 2007 and samples collected in 2019 to determine differences in genetic structure of P. perna over time. This thesis further investigated the reproductive timing of the two lineages to determine if this contributes to the maintenance of the genetic structure of this species. The results show that there is a shift in the distribution of the Eastern lineage since 2007, an increase in the range of the overlap region, and there was a change in genetic diversity in the form of private haplotypes between 2007 and 2019. The lineages have unsynchronised spawning and reproductive patterns are more closely linked to changes in temperature. While the lineages have shown slight distributional changes over time, the influence of environmental conditions and the predicted changes in sea surface temperatures could see a change in future populations’ fitness and dispersal. Thus, changes in sea surface temperature could affect reproductive timing and the future genetic stability of the species. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-10
A content analysis of fan perceptions of the South African soap opera 7de Laan
- Authors: Tsewu, Xola
- Date: 2021-05
- Subjects: Television soap operas , Television program genres
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23226 , vital:56477
- Description: Soap operas are no longer only televised but the producers or content creators are branching out to other media, to make their content available to all kinds of audience. Increasingly, soap opera episodes can be shared not only on TV but also on the internet and this means its audience reach is extended. The focus of the study was on online audience of the South African soap opera 7de Laan, this exploratory study was conducted to assess the participation and activities of an online fan community. The study focused on a convenience sample of 10 asynchronous commentary forums attached to the 7de Laan YouTube channel. The sample included 1011 participants collectively providing 2312 comments. User names are not used in this study. The study intended to achieve the following objectives: 1. To conduct a qualitative content analysis of references to characters during the course of the ten episodes; 2. To find out what the users say about those characters and the plots in which they occur; and 3. To measure the coding in order to gain an impression of the interests and concerns of participants making up the online audience with respect to the soap opera narrative. The data set was coded and explored by means of the Qualitative data analysis programme NVivo 10. The raw material was collated into individual files for each participant, and imported into analysis programme. The analysis proceeded as three stages. The first stage revealed those characters that interested participants, ranging from those who attracted the most interest, to those who attracted the least. The second stage aimed to find out what themes coincided with these characters. The third stage aimed to find out what participants through about the soap opera 7de Laan itself. These stages correspond to three sets of appendices. The findings show a close correspondence between the relative airing of the five sub-plots that constitute the soap opera narrative, and the interest that online audience participants show through their comments. , Thesis (MSoc Sci) (Communication) --Faculty of Social Science and Humanities , 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Tsewu, Xola
- Date: 2021-05
- Subjects: Television soap operas , Television program genres
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23226 , vital:56477
- Description: Soap operas are no longer only televised but the producers or content creators are branching out to other media, to make their content available to all kinds of audience. Increasingly, soap opera episodes can be shared not only on TV but also on the internet and this means its audience reach is extended. The focus of the study was on online audience of the South African soap opera 7de Laan, this exploratory study was conducted to assess the participation and activities of an online fan community. The study focused on a convenience sample of 10 asynchronous commentary forums attached to the 7de Laan YouTube channel. The sample included 1011 participants collectively providing 2312 comments. User names are not used in this study. The study intended to achieve the following objectives: 1. To conduct a qualitative content analysis of references to characters during the course of the ten episodes; 2. To find out what the users say about those characters and the plots in which they occur; and 3. To measure the coding in order to gain an impression of the interests and concerns of participants making up the online audience with respect to the soap opera narrative. The data set was coded and explored by means of the Qualitative data analysis programme NVivo 10. The raw material was collated into individual files for each participant, and imported into analysis programme. The analysis proceeded as three stages. The first stage revealed those characters that interested participants, ranging from those who attracted the most interest, to those who attracted the least. The second stage aimed to find out what themes coincided with these characters. The third stage aimed to find out what participants through about the soap opera 7de Laan itself. These stages correspond to three sets of appendices. The findings show a close correspondence between the relative airing of the five sub-plots that constitute the soap opera narrative, and the interest that online audience participants show through their comments. , Thesis (MSoc Sci) (Communication) --Faculty of Social Science and Humanities , 2021
- Full Text:
- Date Issued: 2021-05
An analysis of orthographic errors in isiXhosa texts: a case of grade 11 isiXhosa home language (l1) in the Western Cape
- Authors: Titi, Nonzolo
- Date: 2021-05
- Subjects: Language and languages -- Orthography and spelling
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22210 , vital:51998
- Description: This case study reveals that the written language of a group of Grade 11 isiXhosa first language (L1) learners presents errors which seem to have serious implications for their linguistic competence, performance in their learning, language development and language conservation. These errors include different regular language components, such as grammar, spelling, word division, punctuation, vocabulary, capitalization, syntax and semantics. Additional to these errors are the newly discovered categories of anomalies, such as new lexical items, incomplete words, incorrect word construction, inter-categorical range, multiple deviations and writing inconsistencies. The writing of these learners not only reflects various orthographic errors and inconsistency in their usage of isiXhosa, which translates into language deficiency, but also implies gaps within the education system and its policies, as well as inefficient isiXhosa curriculum design as some of the factors contributing to the existence of these errors. Possible causes of these errors include educational causes; lack of orthographic knowledge and limited reading, socio-cultural causes; interference of other languages and the influence of the media, and attitudinal causes; lack of respect and contempt for the language and lack of learner interest in the language. Adopting a combined mixed method with a predominantly qualitative approach, this study examines errors presented in the writings of Grade 11 isiXhosa L1 learners with a view to establishing the nature and scope of these errors. The key objectives of this study were investigated by means of scientific papers both published and publishable as book chapters, books, dissertations, education policies, online publications and journal articles - both international and accredited journals. Drawing on various conceptual and analytical frameworks (Hymes 1972; Corder 1981), the study scrutinizes the contents and presents observations of the elements and themes that emanate from the eighteen (18) learners’ isiXhosa essays and seven (7) voice-recorded isiXhosa teachers and subject advisers’ interviews which were used as data. Findings reveal that learners struggle to master some language aspects, with their usage reflecting serious deviations from the standard orthography. These findings have serious implications for language teaching and learning as these errors tend to affect the learners’ linguistic competence and performance, language development, as well as language conservation. Also, serious violations of the standard orthographic rules are noticeable; and this observation raises concerns about the fate and sustainability of the language. It is recommended that interventions and strategies be applied in respect of the teaching and learning of isiXhosa in order to maintain its standard orthography, to preserve the language, improve the learning and teaching of the language, maintain communicative competence and facilitate appropriate application of the language in a learning context, especially in speaking and writing. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Titi, Nonzolo
- Date: 2021-05
- Subjects: Language and languages -- Orthography and spelling
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22210 , vital:51998
- Description: This case study reveals that the written language of a group of Grade 11 isiXhosa first language (L1) learners presents errors which seem to have serious implications for their linguistic competence, performance in their learning, language development and language conservation. These errors include different regular language components, such as grammar, spelling, word division, punctuation, vocabulary, capitalization, syntax and semantics. Additional to these errors are the newly discovered categories of anomalies, such as new lexical items, incomplete words, incorrect word construction, inter-categorical range, multiple deviations and writing inconsistencies. The writing of these learners not only reflects various orthographic errors and inconsistency in their usage of isiXhosa, which translates into language deficiency, but also implies gaps within the education system and its policies, as well as inefficient isiXhosa curriculum design as some of the factors contributing to the existence of these errors. Possible causes of these errors include educational causes; lack of orthographic knowledge and limited reading, socio-cultural causes; interference of other languages and the influence of the media, and attitudinal causes; lack of respect and contempt for the language and lack of learner interest in the language. Adopting a combined mixed method with a predominantly qualitative approach, this study examines errors presented in the writings of Grade 11 isiXhosa L1 learners with a view to establishing the nature and scope of these errors. The key objectives of this study were investigated by means of scientific papers both published and publishable as book chapters, books, dissertations, education policies, online publications and journal articles - both international and accredited journals. Drawing on various conceptual and analytical frameworks (Hymes 1972; Corder 1981), the study scrutinizes the contents and presents observations of the elements and themes that emanate from the eighteen (18) learners’ isiXhosa essays and seven (7) voice-recorded isiXhosa teachers and subject advisers’ interviews which were used as data. Findings reveal that learners struggle to master some language aspects, with their usage reflecting serious deviations from the standard orthography. These findings have serious implications for language teaching and learning as these errors tend to affect the learners’ linguistic competence and performance, language development, as well as language conservation. Also, serious violations of the standard orthographic rules are noticeable; and this observation raises concerns about the fate and sustainability of the language. It is recommended that interventions and strategies be applied in respect of the teaching and learning of isiXhosa in order to maintain its standard orthography, to preserve the language, improve the learning and teaching of the language, maintain communicative competence and facilitate appropriate application of the language in a learning context, especially in speaking and writing. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-05
An evaluation of agricultural extension as a measure to improve broad-based Black economic empowerment in -the Eastern Cape Province: the case of orTambo District Municipality.
- Authors: Mambila, Lawrence Nzimeni
- Date: 2021-05
- Subjects: Food security , Agricultural extension work , Land tenure
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21333 , vital:48486
- Description: This research evaluates the extent to which broad-based black economic empowerment has been achieved as a result of the implementation of different agricultural · extension programmes in Mthatha. The overall analysis and interpretation of the findings imply that to a significant extent, broad-based black economic empowerment has been_ achieved as a result of the implementation of different agricultural extension programmes in Mthatha. This is attributable to the fact that as much as some of the respondents disagreed, most of the - 97 sampled farmers were also ·found to agree that the implementation of different agricultural extension programmes in Mthatha has influenced increased farm ownership by black farmers increase in land ownership by black farmers, the development of farming skills of black farmers and increased embracement of agriculture, as a business. Some of the sampled 97 farmers also acknowledged that such agricultural extension programmes have influenced improvement in productivity and production to boost the socio-economic development of the communities in Mthatha, expansion of numerous employment opportunities .to catalyse increase in sources of income for communities in Mthatha and improvement in food security to leverage the economic independence of communities in Mthatha. However, despite some significant progress, findings imply that there are challenges that are marring the achievement of broad-based black economic empowerment. It emerged from the findings that challenges of implementation of agricultural extension programmes, as mechanisms for achieving broad-based black economic empowerment in Mthatha, arise from lack of financial capital, poor support from government, low motivation among the population and emergence of natural calamities such as stronger sunshine that causes draught. To address the above challenges, the survey explored the opinions of the participants on intervention measures that can be undertaken. The survey results indicated that measures used for ensuring that the implementation of agricultural extension programmes impact on the improvement of broad-based black economic empowerment encompass constant training and visit by agricultural specialists from Mthatha Department of Agriculture, the use of ordinary farmers as trainers, encouragement of farmers to form groups, as a basis for training community members and frequent intervention from the district, if needed. , Thesis (MCom) (Development Studies) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Mambila, Lawrence Nzimeni
- Date: 2021-05
- Subjects: Food security , Agricultural extension work , Land tenure
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21333 , vital:48486
- Description: This research evaluates the extent to which broad-based black economic empowerment has been achieved as a result of the implementation of different agricultural · extension programmes in Mthatha. The overall analysis and interpretation of the findings imply that to a significant extent, broad-based black economic empowerment has been_ achieved as a result of the implementation of different agricultural extension programmes in Mthatha. This is attributable to the fact that as much as some of the respondents disagreed, most of the - 97 sampled farmers were also ·found to agree that the implementation of different agricultural extension programmes in Mthatha has influenced increased farm ownership by black farmers increase in land ownership by black farmers, the development of farming skills of black farmers and increased embracement of agriculture, as a business. Some of the sampled 97 farmers also acknowledged that such agricultural extension programmes have influenced improvement in productivity and production to boost the socio-economic development of the communities in Mthatha, expansion of numerous employment opportunities .to catalyse increase in sources of income for communities in Mthatha and improvement in food security to leverage the economic independence of communities in Mthatha. However, despite some significant progress, findings imply that there are challenges that are marring the achievement of broad-based black economic empowerment. It emerged from the findings that challenges of implementation of agricultural extension programmes, as mechanisms for achieving broad-based black economic empowerment in Mthatha, arise from lack of financial capital, poor support from government, low motivation among the population and emergence of natural calamities such as stronger sunshine that causes draught. To address the above challenges, the survey explored the opinions of the participants on intervention measures that can be undertaken. The survey results indicated that measures used for ensuring that the implementation of agricultural extension programmes impact on the improvement of broad-based black economic empowerment encompass constant training and visit by agricultural specialists from Mthatha Department of Agriculture, the use of ordinary farmers as trainers, encouragement of farmers to form groups, as a basis for training community members and frequent intervention from the district, if needed. , Thesis (MCom) (Development Studies) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
Application of geophysical methods to investigate the subsurface geology of Kuruman and Kono areas in Griqualand West Basin, South Africa
- Authors: Mthintweni, Sylvia Lwandisa
- Date: 2021-05
- Subjects: Geology , Soil surveys--Geophysical methods
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22555 , vital:52456
- Description: Kono and Kuruman areas belong to the geology of the Campbell Rand and Asbestos Hills Subgroups, Ghaap Group in the Griqualand West Basin. Campbell Rand Subgroup comprises interbedded chert, limestone and dolomite rocks of dominantly the Kogelbeen Formation covered with a thick regolith of red sand and weathered material. The Asbestos Hills Subgroup consists of a banded iron formation (BIF) of the Kuruman Formation overlain by the Kalahari sands. Petrographic and mineralogical analyses and various geophysical methods were utilised to investigate the surface and subsurface conditions of the study areas. This study was done to characterize and understand the geology of Kuruman and Kono and identify the structural lineaments. Rock samples of varying lithology were collected in the field for laboratory analyses that include preparation of thin sections and petrographic analyses and density and porosity determinations. Both the petrographic results and XRF analyses revealed that iron oxide (Fe2O3) and silica (SiO2) are the most abundant minerals in BIF. Iron oxide and silica percentages range between 21.17-39.97 wt % and 59.03-78.01 wt %, respectively. BIF has an average density of 3.0 g/cm3 and porosity of 2.51% and dolomite has an average density of 2.8 g/cm3 and porosity of 0.17%. The Bouguer anomaly values range between - 119.00 mGal and -1 17.29 mGals. High gravity anomalies are attributed to shallow fresh bedrock and this was confirmed by the seismic line that cuts across the map. The gravity high observed in the Kuruman profile coincides with the thick BIF body observed in the field. The gravity analytic signal indicates a width of about 1125 m for the BIF and inferred two normal faults at about 675 m and 1500 m. The high magnetic anomalies in the ground magnetic map correspond to chert rich dolomite ridges in the field and the intermediate to lows correspond to dolomitic terrains. A geological map was superimposed on an aeromagnetic map to correlate the two. The linear magnetic high trending from NW – SE coincide with BIF. Older dykes trending east-west were intruded by younger dykes trending north-south. The total counts channel map for Kono area shows the measured total gamma radiation count in the study area and the concentrations of radioelements range between 51.84 and 94.64 counts/sec. The concentrations of potassium, thorium and uranium range from 0.12 – 0.51%, 0.83 – 5.23 ppm and 0.06 – 2.27 ppm, respectively. A high concentration of radiometric elements cutting through the central part of the map stretching from northwest to southeast was observed in a ternary map and this could be associated with chert rich dolomite outcrops. Seismic refraction tomography (SRT) cross-section for study area 1 in Kono revealed 3 different layers. The topmost layer comprises sand and loose material and has a velocity ranging from 614 – 1194 m/s. It is underlain by highly to slightly weathered dolomite with a velocity that ranges from 1774 – 2354 m/s. Layer 3 is the fresh bedrock dolomite and has a velocity of 2934 m/s. Three layers were observed in study area 2 for Kuruman. Layer 1 had a velocity of 300 – 750 m/s, the second layer had a velocity of 1200 – 2100 m/s and the bottom layer’s velocity was 2500 – 2999 m/s. An inferred fault is indicated on the western side of the seismic section at about 650 m. The dipole-dipole resistivity model for the main survey line in Kono revealed that the area is underlain by fractured bedrock with high resistivity in places. A thick conductive stratum was observed at the beginning of the line. The resistivity models for the sinkhole in Kono were characterized into three resistivity zones. High resistivity values (1000 – 134202 Ωm) are due to slightly weathered to fresh bedrock, intermediate values (24 – 5770 Ωm) are interpreted to be due to highly weathered dolomite and compacted dolomitic soils and very low resistivity zones (4 – 397 Ωm) are inferred to be karstic cavities. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Mthintweni, Sylvia Lwandisa
- Date: 2021-05
- Subjects: Geology , Soil surveys--Geophysical methods
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22555 , vital:52456
- Description: Kono and Kuruman areas belong to the geology of the Campbell Rand and Asbestos Hills Subgroups, Ghaap Group in the Griqualand West Basin. Campbell Rand Subgroup comprises interbedded chert, limestone and dolomite rocks of dominantly the Kogelbeen Formation covered with a thick regolith of red sand and weathered material. The Asbestos Hills Subgroup consists of a banded iron formation (BIF) of the Kuruman Formation overlain by the Kalahari sands. Petrographic and mineralogical analyses and various geophysical methods were utilised to investigate the surface and subsurface conditions of the study areas. This study was done to characterize and understand the geology of Kuruman and Kono and identify the structural lineaments. Rock samples of varying lithology were collected in the field for laboratory analyses that include preparation of thin sections and petrographic analyses and density and porosity determinations. Both the petrographic results and XRF analyses revealed that iron oxide (Fe2O3) and silica (SiO2) are the most abundant minerals in BIF. Iron oxide and silica percentages range between 21.17-39.97 wt % and 59.03-78.01 wt %, respectively. BIF has an average density of 3.0 g/cm3 and porosity of 2.51% and dolomite has an average density of 2.8 g/cm3 and porosity of 0.17%. The Bouguer anomaly values range between - 119.00 mGal and -1 17.29 mGals. High gravity anomalies are attributed to shallow fresh bedrock and this was confirmed by the seismic line that cuts across the map. The gravity high observed in the Kuruman profile coincides with the thick BIF body observed in the field. The gravity analytic signal indicates a width of about 1125 m for the BIF and inferred two normal faults at about 675 m and 1500 m. The high magnetic anomalies in the ground magnetic map correspond to chert rich dolomite ridges in the field and the intermediate to lows correspond to dolomitic terrains. A geological map was superimposed on an aeromagnetic map to correlate the two. The linear magnetic high trending from NW – SE coincide with BIF. Older dykes trending east-west were intruded by younger dykes trending north-south. The total counts channel map for Kono area shows the measured total gamma radiation count in the study area and the concentrations of radioelements range between 51.84 and 94.64 counts/sec. The concentrations of potassium, thorium and uranium range from 0.12 – 0.51%, 0.83 – 5.23 ppm and 0.06 – 2.27 ppm, respectively. A high concentration of radiometric elements cutting through the central part of the map stretching from northwest to southeast was observed in a ternary map and this could be associated with chert rich dolomite outcrops. Seismic refraction tomography (SRT) cross-section for study area 1 in Kono revealed 3 different layers. The topmost layer comprises sand and loose material and has a velocity ranging from 614 – 1194 m/s. It is underlain by highly to slightly weathered dolomite with a velocity that ranges from 1774 – 2354 m/s. Layer 3 is the fresh bedrock dolomite and has a velocity of 2934 m/s. Three layers were observed in study area 2 for Kuruman. Layer 1 had a velocity of 300 – 750 m/s, the second layer had a velocity of 1200 – 2100 m/s and the bottom layer’s velocity was 2500 – 2999 m/s. An inferred fault is indicated on the western side of the seismic section at about 650 m. The dipole-dipole resistivity model for the main survey line in Kono revealed that the area is underlain by fractured bedrock with high resistivity in places. A thick conductive stratum was observed at the beginning of the line. The resistivity models for the sinkhole in Kono were characterized into three resistivity zones. High resistivity values (1000 – 134202 Ωm) are due to slightly weathered to fresh bedrock, intermediate values (24 – 5770 Ωm) are interpreted to be due to highly weathered dolomite and compacted dolomitic soils and very low resistivity zones (4 – 397 Ωm) are inferred to be karstic cavities. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
Aspects of the ecology of the estuarine round-herring Gilchristella aestuaria (Pisces: Clupeidae) and its small-scale fishery potential
- Zvavahera, Munetsi https://orcid.org/0000-0002-5337-1943
- Authors: Zvavahera, Munetsi https://orcid.org/0000-0002-5337-1943
- Date: 2021-05
- Subjects: Small-scale fisheries , Silversides
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22765 , vital:52752
- Description: In the past two decades, there has been increasing pressure for small-scale inland fisheries to play a central role in food and nutrient security for poor communities in South Africa. For decades, South African inland fisheries have focussed on the exploitation of large fish species and generally ignored the exploitation of inland small fish species (SFS). This research aimed to assess the ecology and small-scale fishery potential of the estuarine round-herring, Gilchristella aestuaria. To understand the ecology of G. aestuaria better, morphometric trait analysis and fish condition of populations in relation to environmental variables (salinity, pH, temperature, turbidity and chlorophyll-a) were done. Fish were supplemented with samples acquired from the SAIAB collection facility for 14 sites to cover all the three South African biogeographic regions, stretching from Lake Sibaya (KZN) to the Orange River estuary in the western parts of the country. The morphometric trait analysis showed that G. aestuaria populations can be distinguished based on the trait variation, however there were many overlaps for populations that are interconnected, with distant/ geographically separated populations showing clear differences. Morphometric traits of the G. aestuaria population were significantly different, however there was no strong directional relationship with environmental variables and variation in morphometric traits. However, fish condition as measured by Fulton’s condition (K) and relative weight (Wr) showed variation between populations found in different environments. These differences suggest that these populations must be managed differently if G. aestuaria is to be exploited in managed fisheries. To determine the potential nutrient value of G. aestuaria to the human diet, samples from two freshwater sites and five estuarine sites were analysed for essential macro and micronutrients. The nutrient content of G. aestuaria revealed there is potential for exploitation, as the species has a high macro (protein and fat) and micronutrient composition (calcium, iron and zinc). Mean ± SD of selected nutrients were protein (61.7±5.0 g/100g), fat (20.4±3.7g/ 100g), calcium (3507.5±314.0mg), iron (40.37±14.0mg/ 100g), zinc (22.47±5.6mg/ 100) and vitamin A (37.3±44.4 RAE/ 100g). The nutrient composition of fish collected from freshwater sites was comparable to those collected from estuarine environments. Using the recommended dietary allowances (RDA) from literature, the mass of fish and the number of fish that would provide a minimum amount for each nutrient were calculated. A child would require only 13.4g of dry G. aestuaria or approximately 74 dried fish to meet the daily requirements of zinc. Other minerals such as iron and calcium also showed a similar low weight or number of fish required to meet daily requirements for the different categories. A small number of G. aestuaria are needed to meet RDA for groups (children, adult men, adult women, pregnant women and lactating mothers). A comparison was done for the nutrient composition of G. aestuaria with reference species that are already harvested for human consumption in some African and Asian countries. The protein content of G. aestuaria was comparable to Chisense (Microthrissa moeruensis) and Kapenta Limnothrissa miodon), while the fat composition was more than twice Chisense and Kapenta. Comparing the mineral composition, G. aestuaria had more than three times higher calcium than Mola (Amblypharyngodon mola) and Puti (Puntius sophore). Zinc composition was four times higher than M. moeruensis and L. miodon. Further exploration of the ecology of G. aestuaria was studied using the Sundays River irrigations ponds as a case study that would represent small impoundments across South Africa. Species rank abundance curve and catch per unit effort (CPUE) on the Sundays Irrigation ponds revealed that G. aestuaria dominated numerically and biomass in the Sundays River irrigation ponds. To assess the potential of harvesting G. aestuaria harvesting experiments were conducted using depletion (removal) sampling. Catchweight (kg) ranged from 2.16 (1.03; 3.28) to 61.25 (44.40; 78.09) kg and the estimated biomass from the depletion model ranged from 1.05 to 40.19 kg/ha for September 2019. The depletion model revealed that small impoundments have high biomass per hectare of G. aestuaria ranging from which indicates that the species may not support a commercial fishery but small-scale fisheries. In conclusion, G. aestuaria could become a meaningful contribution to the food and nutrient security of poor communities where available as a food source through small-scale fishery exploitation. The extent of this contribution may depend on its production potential in various regions and environments. More research is however needed to determine the long-term sustainability of harvesting of G aestuaria by looking at how populations respond to harvesting. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Zvavahera, Munetsi https://orcid.org/0000-0002-5337-1943
- Date: 2021-05
- Subjects: Small-scale fisheries , Silversides
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22765 , vital:52752
- Description: In the past two decades, there has been increasing pressure for small-scale inland fisheries to play a central role in food and nutrient security for poor communities in South Africa. For decades, South African inland fisheries have focussed on the exploitation of large fish species and generally ignored the exploitation of inland small fish species (SFS). This research aimed to assess the ecology and small-scale fishery potential of the estuarine round-herring, Gilchristella aestuaria. To understand the ecology of G. aestuaria better, morphometric trait analysis and fish condition of populations in relation to environmental variables (salinity, pH, temperature, turbidity and chlorophyll-a) were done. Fish were supplemented with samples acquired from the SAIAB collection facility for 14 sites to cover all the three South African biogeographic regions, stretching from Lake Sibaya (KZN) to the Orange River estuary in the western parts of the country. The morphometric trait analysis showed that G. aestuaria populations can be distinguished based on the trait variation, however there were many overlaps for populations that are interconnected, with distant/ geographically separated populations showing clear differences. Morphometric traits of the G. aestuaria population were significantly different, however there was no strong directional relationship with environmental variables and variation in morphometric traits. However, fish condition as measured by Fulton’s condition (K) and relative weight (Wr) showed variation between populations found in different environments. These differences suggest that these populations must be managed differently if G. aestuaria is to be exploited in managed fisheries. To determine the potential nutrient value of G. aestuaria to the human diet, samples from two freshwater sites and five estuarine sites were analysed for essential macro and micronutrients. The nutrient content of G. aestuaria revealed there is potential for exploitation, as the species has a high macro (protein and fat) and micronutrient composition (calcium, iron and zinc). Mean ± SD of selected nutrients were protein (61.7±5.0 g/100g), fat (20.4±3.7g/ 100g), calcium (3507.5±314.0mg), iron (40.37±14.0mg/ 100g), zinc (22.47±5.6mg/ 100) and vitamin A (37.3±44.4 RAE/ 100g). The nutrient composition of fish collected from freshwater sites was comparable to those collected from estuarine environments. Using the recommended dietary allowances (RDA) from literature, the mass of fish and the number of fish that would provide a minimum amount for each nutrient were calculated. A child would require only 13.4g of dry G. aestuaria or approximately 74 dried fish to meet the daily requirements of zinc. Other minerals such as iron and calcium also showed a similar low weight or number of fish required to meet daily requirements for the different categories. A small number of G. aestuaria are needed to meet RDA for groups (children, adult men, adult women, pregnant women and lactating mothers). A comparison was done for the nutrient composition of G. aestuaria with reference species that are already harvested for human consumption in some African and Asian countries. The protein content of G. aestuaria was comparable to Chisense (Microthrissa moeruensis) and Kapenta Limnothrissa miodon), while the fat composition was more than twice Chisense and Kapenta. Comparing the mineral composition, G. aestuaria had more than three times higher calcium than Mola (Amblypharyngodon mola) and Puti (Puntius sophore). Zinc composition was four times higher than M. moeruensis and L. miodon. Further exploration of the ecology of G. aestuaria was studied using the Sundays River irrigations ponds as a case study that would represent small impoundments across South Africa. Species rank abundance curve and catch per unit effort (CPUE) on the Sundays Irrigation ponds revealed that G. aestuaria dominated numerically and biomass in the Sundays River irrigation ponds. To assess the potential of harvesting G. aestuaria harvesting experiments were conducted using depletion (removal) sampling. Catchweight (kg) ranged from 2.16 (1.03; 3.28) to 61.25 (44.40; 78.09) kg and the estimated biomass from the depletion model ranged from 1.05 to 40.19 kg/ha for September 2019. The depletion model revealed that small impoundments have high biomass per hectare of G. aestuaria ranging from which indicates that the species may not support a commercial fishery but small-scale fisheries. In conclusion, G. aestuaria could become a meaningful contribution to the food and nutrient security of poor communities where available as a food source through small-scale fishery exploitation. The extent of this contribution may depend on its production potential in various regions and environments. More research is however needed to determine the long-term sustainability of harvesting of G aestuaria by looking at how populations respond to harvesting. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
Assessing Drought Conditions using NDVI, Land Surface Temperature and Precipitation in Amathole District Municipality, Eastern Cape, Province, South Africa
- Authors: Dyosi, Masonwabe
- Date: 2021-05
- Subjects: Remote sensing , Earth sciences--Remote sensing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20793 , vital:46570
- Description: The world is faced with unprecedented environmental changes, which can be linked to population growth, and economic development. Several studies have indicated that these changes are likely to accelerate in the future and cause adverse impact on the environment. To this end, the Eastern Cape Province and in particular the Amathole District Municipality (ADM) has recorded high number of climate change related disasters such as prolonged drought conditions witnessed during the winter season of 2008, 2009, 2014 and 2015 among others. To this end, this study aimed to use remote sensing imagery to assess and document drought occurrences in the ADM from 2007 to 2017. To accomplish the aim, the Normalized Difference Vegetation Index, Land Surface Temperature and Precipitation were explored to assess drought spatiotemporal occurrences. To assess the relationship between abovementioned variables, the Pearson’s correlation was used. For the analysis a total of 396 satellite imagery (MODIS NDVI and Land Surface Temperature as well as TRMM precipitation) were used. The study results revealed that different correlations exist between the three variables. The strength of correlations differed by season. Furthermore, it was revealed that the drought conditions in the district differed in the spatial distribution. The study accurately identified the drought episodes which occurred in the ADM in the years 2008, 2009, 2014, 2015 and 2016. The chosen methodology and variables proved to be suitable for analysing drought conditions offering space and temporal variation dimension, which is vital in monitoring disasters such as drought. , Thesis (MSc) (Geography) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Dyosi, Masonwabe
- Date: 2021-05
- Subjects: Remote sensing , Earth sciences--Remote sensing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20793 , vital:46570
- Description: The world is faced with unprecedented environmental changes, which can be linked to population growth, and economic development. Several studies have indicated that these changes are likely to accelerate in the future and cause adverse impact on the environment. To this end, the Eastern Cape Province and in particular the Amathole District Municipality (ADM) has recorded high number of climate change related disasters such as prolonged drought conditions witnessed during the winter season of 2008, 2009, 2014 and 2015 among others. To this end, this study aimed to use remote sensing imagery to assess and document drought occurrences in the ADM from 2007 to 2017. To accomplish the aim, the Normalized Difference Vegetation Index, Land Surface Temperature and Precipitation were explored to assess drought spatiotemporal occurrences. To assess the relationship between abovementioned variables, the Pearson’s correlation was used. For the analysis a total of 396 satellite imagery (MODIS NDVI and Land Surface Temperature as well as TRMM precipitation) were used. The study results revealed that different correlations exist between the three variables. The strength of correlations differed by season. Furthermore, it was revealed that the drought conditions in the district differed in the spatial distribution. The study accurately identified the drought episodes which occurred in the ADM in the years 2008, 2009, 2014, 2015 and 2016. The chosen methodology and variables proved to be suitable for analysing drought conditions offering space and temporal variation dimension, which is vital in monitoring disasters such as drought. , Thesis (MSc) (Geography) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
Coastal urban climate change adaptation and disaster risk reduction assessment: the case of East London city, South Africa
- Busayo, Emmanuel Tolulope https://orcid.org/ 0000-0002-9274-2145
- Authors: Busayo, Emmanuel Tolulope https://orcid.org/ 0000-0002-9274-2145
- Date: 2021-05
- Subjects: Climate change mitigation , Climatic changes , Emergency management
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20938 , vital:46756
- Description: The increasing incidences of climate change and its registered negative effects have disturbed the entire world, with the coastal areas being the worst hit. Given the fact that coastal areas are becoming centres of global population settlement. An attempt to explore climate change-related disasters and risks is an important aspect in building communities' adaptation and resilience, especially for the most vulnerable global south. Consequently, climate change adaptation (CCA) and disaster risk reduction (DRR) have become fundamentally linked to offering sustainable solutions to address climate change and related disaster risk problems witnessed frequently in recent years. However, the assessment of synergy between CCA and DRR for coastal areas remains fragmented, vague and limited, especially for Sub-Saharan Africa and thus the need for exploration. Furthermore, the urban populace and planning stakeholders are grappling with the challenges of seeking ways to integrate adaptation measures into human livelihoods and planning systems. Also, considering complex issues inhibiting sustainable planning, for example, poor communication of climate risks affecting coastal areas, little records of hazards disclosure and disaster history, inundation and/or sea level rise etc warranted further investigation. Accordingly, the synergies between CCA and DRR in addressing various climate change-related disaster risks, especially for the coastal areas and cities was explored in this study. To this end, given the complexity of CCA and DRR, trio-theories were adopted, which included Resilience Theory (RT), Social Vulnerability Theory (SVT) and Protective Motivation Theory (PMT) as the study’s theoretical underpinnings using East London Coastal City as a case study. Consequently, a multi-method approach was employed using a review of literature, bibliometric analysis, field survey, geographic information system (GIS), and remote sensing. The first objective reveals that there is a need for convergence and harmonisation of CCA and DRR policy, programme, and practice to improve sustainable planning outcomes. Accordingly, the study proposed the adoption of a problem analysis model (PAM) for place function sustainability and local or community level resilience building. The second objective revealed that the Sendai framework for disaster risk reduction has not been fully operationalised at the local and global scales. However, in South Africa, there are efforts to streamline DRR across manifold sectors through the Integrated Urban Development Framework (IUDF). Therefore, disaster risk managers and climate change adaptation stakeholders at the local level need to embrace the position of the SFDRR to possibly offer sound and sustainable results to the most vulnerable. In addition, a bibliometric analysis on climate change adaptation from 1996 – 2019 highlights the need for more African countries' engagement and cross-collaboration between developing and developed countries in CCA research to advance sustainable solutions and improve resilience. The third objective revealed the need for more awareness, flexibility, and adaptability among stakeholders at various levels as fundamental ingredients for CCA and DRR sustainable planning outcomes. The fourth objective highlighted that floods were recorded as the most predominant hydro-meteorological hazard (n=118, 81.9percent) in the East London, coastal city. Finally, the fifth objective portrayed that many communities, populace, buildings (types), and areas are exposed to flood disaster risks, especially, communities such as Nahoon Park Valley, Sunrise on Sea, Beacon Bay, Buffalo, Gonubie, and East London are among the most vulnerable. The study recommends that early action and warning systems should be adopted, and allocation proper building codes to boost awareness to reduce the potential flood disaster risks. Moreover, the study reveals the significance of local flood disaster risk mapping in advancing CCA and DRR to ensure the implementation of coherent spatial planning for sustainable planning outcomes. The overall lessons learnt from this study are vital in contributing to the attainment of the sustainable development goals (SDGs) such as goal 11: sustainable cities and communities, and goal 13: climate action, including the seven targets and four priorities for action of the Sendai framework at a local level. The study results are deemed critical in guiding city planners, decision-makers, disaster risk managers, local communities among others towards the development of a more resilient coastal community. In general, the study calls for the integration of CCA and DRR initiatives to be premised on PAM for sustainable planning outcomes to achieve sustainable development goals and reduction of fatalities from climate-related disasters. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Busayo, Emmanuel Tolulope https://orcid.org/ 0000-0002-9274-2145
- Date: 2021-05
- Subjects: Climate change mitigation , Climatic changes , Emergency management
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20938 , vital:46756
- Description: The increasing incidences of climate change and its registered negative effects have disturbed the entire world, with the coastal areas being the worst hit. Given the fact that coastal areas are becoming centres of global population settlement. An attempt to explore climate change-related disasters and risks is an important aspect in building communities' adaptation and resilience, especially for the most vulnerable global south. Consequently, climate change adaptation (CCA) and disaster risk reduction (DRR) have become fundamentally linked to offering sustainable solutions to address climate change and related disaster risk problems witnessed frequently in recent years. However, the assessment of synergy between CCA and DRR for coastal areas remains fragmented, vague and limited, especially for Sub-Saharan Africa and thus the need for exploration. Furthermore, the urban populace and planning stakeholders are grappling with the challenges of seeking ways to integrate adaptation measures into human livelihoods and planning systems. Also, considering complex issues inhibiting sustainable planning, for example, poor communication of climate risks affecting coastal areas, little records of hazards disclosure and disaster history, inundation and/or sea level rise etc warranted further investigation. Accordingly, the synergies between CCA and DRR in addressing various climate change-related disaster risks, especially for the coastal areas and cities was explored in this study. To this end, given the complexity of CCA and DRR, trio-theories were adopted, which included Resilience Theory (RT), Social Vulnerability Theory (SVT) and Protective Motivation Theory (PMT) as the study’s theoretical underpinnings using East London Coastal City as a case study. Consequently, a multi-method approach was employed using a review of literature, bibliometric analysis, field survey, geographic information system (GIS), and remote sensing. The first objective reveals that there is a need for convergence and harmonisation of CCA and DRR policy, programme, and practice to improve sustainable planning outcomes. Accordingly, the study proposed the adoption of a problem analysis model (PAM) for place function sustainability and local or community level resilience building. The second objective revealed that the Sendai framework for disaster risk reduction has not been fully operationalised at the local and global scales. However, in South Africa, there are efforts to streamline DRR across manifold sectors through the Integrated Urban Development Framework (IUDF). Therefore, disaster risk managers and climate change adaptation stakeholders at the local level need to embrace the position of the SFDRR to possibly offer sound and sustainable results to the most vulnerable. In addition, a bibliometric analysis on climate change adaptation from 1996 – 2019 highlights the need for more African countries' engagement and cross-collaboration between developing and developed countries in CCA research to advance sustainable solutions and improve resilience. The third objective revealed the need for more awareness, flexibility, and adaptability among stakeholders at various levels as fundamental ingredients for CCA and DRR sustainable planning outcomes. The fourth objective highlighted that floods were recorded as the most predominant hydro-meteorological hazard (n=118, 81.9percent) in the East London, coastal city. Finally, the fifth objective portrayed that many communities, populace, buildings (types), and areas are exposed to flood disaster risks, especially, communities such as Nahoon Park Valley, Sunrise on Sea, Beacon Bay, Buffalo, Gonubie, and East London are among the most vulnerable. The study recommends that early action and warning systems should be adopted, and allocation proper building codes to boost awareness to reduce the potential flood disaster risks. Moreover, the study reveals the significance of local flood disaster risk mapping in advancing CCA and DRR to ensure the implementation of coherent spatial planning for sustainable planning outcomes. The overall lessons learnt from this study are vital in contributing to the attainment of the sustainable development goals (SDGs) such as goal 11: sustainable cities and communities, and goal 13: climate action, including the seven targets and four priorities for action of the Sendai framework at a local level. The study results are deemed critical in guiding city planners, decision-makers, disaster risk managers, local communities among others towards the development of a more resilient coastal community. In general, the study calls for the integration of CCA and DRR initiatives to be premised on PAM for sustainable planning outcomes to achieve sustainable development goals and reduction of fatalities from climate-related disasters. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
Development of a Mobile-Based Livestock Breeding Management System for Communal Farmers in Eastern Cape, South Africa
- Authors: Aduradola, Oluwatobi John
- Date: 2021-05
- Subjects: Mobile communication systems , Mobile computing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20600 , vital:46364
- Description: More than a decade ago, South Africa realized the significance of Information and Communication Technology (ICT) and its use in delivering several services; there are still several challenges that block implementing an ICT-based system to deliver services and information better. Since communal development is still one of the country's biggest concerns, ICT is among several advances and views recognized for speeding up communal development and providing for the country's economic growth. This research aimed to investigate and implement ICT tools for communal farmers in the context of information needs and information dissemination. The research concentrated on the technical tools and skills needed to implement an ICT tool for communal farmers and other stakeholders. A prototyping methodology was used in this research in the development of the required prototype. A study was then conducted to understand the present state and the information needs of communal farmers where the questionnaire was administered. The research results demonstrated the critical need for communal farmers to get information timely at their convenience. A mobile database system was then designed and developed that suits communal farmers' nature. This system was an offline android application that assists with their information need and its dissemination, and it allows the sharing of the communal farmer's data to other stakeholders. , Thesis (MSc) (Computer Science)-- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Aduradola, Oluwatobi John
- Date: 2021-05
- Subjects: Mobile communication systems , Mobile computing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20600 , vital:46364
- Description: More than a decade ago, South Africa realized the significance of Information and Communication Technology (ICT) and its use in delivering several services; there are still several challenges that block implementing an ICT-based system to deliver services and information better. Since communal development is still one of the country's biggest concerns, ICT is among several advances and views recognized for speeding up communal development and providing for the country's economic growth. This research aimed to investigate and implement ICT tools for communal farmers in the context of information needs and information dissemination. The research concentrated on the technical tools and skills needed to implement an ICT tool for communal farmers and other stakeholders. A prototyping methodology was used in this research in the development of the required prototype. A study was then conducted to understand the present state and the information needs of communal farmers where the questionnaire was administered. The research results demonstrated the critical need for communal farmers to get information timely at their convenience. A mobile database system was then designed and developed that suits communal farmers' nature. This system was an offline android application that assists with their information need and its dissemination, and it allows the sharing of the communal farmer's data to other stakeholders. , Thesis (MSc) (Computer Science)-- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
Marketing the Pentecostal churches in Zimbabwe: A critical study of selected churches in Harare
- Hove, Charity https://orcid.org/0000-0001-5579-0992
- Authors: Hove, Charity https://orcid.org/0000-0001-5579-0992
- Date: 2021-05
- Subjects: Pentecostalism , Religion and sociology
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21167 , vital:47216
- Description: Pentecostalism has spread rapidly worldwide and continues to do so, thereby generating scholarly interest on how much church growth was attained through marketing. In Zimbabwe, it is evident that marketing communication has become an essential part of church activities to attract the society. In the case of Pentecostal churches, both church and marketing activities are interrelated, as seen through the increased usage of digital communication marketing strategies to attract followers, especially on social media. With effective marketing, people can be attached to a church, in the same way, they would be attached to a brand. In this regard, this study therefore examined whether fundamental marketing principles apply to the marketing of Pentecostal religiosity in Zimbabwe - focusing on how the churches, church services or products, and prophets are marketed. The study also explored how such church marketing attributes to the popularity of these churches and how ultimately the church marketing communication affects society. Theoretically, Pentecostal churches can utilise Porter’s Five Forces, Marketing Communication Mix, and AIDA Model to maintain a favourable marketing standing. With the presence of communication technologies and the media, the applicability of these marketing theories is effortless, hence the marketing of Pentecostal churches has flourished. This study used a qualitative research design and was conducted on three Pentecostal churches namely the Prophetic Healing and Deliverance Ministries, United Family International Church, and Spirit Embassy (The Good News Church) in Harare, Zimbabwe. The data was gathered from the churches’ Facebook pages, websites, and newspaper articles reporting about the churches. In addition, interviews with church marketing personnel from each church, 30 church members and focus group interviews with 30 non-church members residing close to the Pentecostal churches were conducted. The findings reveal that the Pentecostal churches in Zimbabwe are actively involved in church marketing and have various marketing strategies as any business entity would. However, the churches’ image and efforts aimed at fulfilling social mandates are tainted by several marketing strategies which are used, especially on digital media. In addition, church marketing has promoted commercialised religion and the Pentecostal fraternity is certainly morphing into businesses at the expense of spirituality and religiosity, which is simply an epitome of secularising the sacred. Furthermore, it was established that the marketing strategies used are influential to target markets, such as church members, and the effects are adverse. Hence, this study recommends regulation of Pentecostal churches and proposes three models that illustrate regulation at government level, collective level, and individual level through policy regulation, collective action, and self-regulation respectively. This will encourage churches to conduct ethical church marketing and protect religious consumers. , Thesis (PhD) -- Faculty of Social Science and Humanities, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Hove, Charity https://orcid.org/0000-0001-5579-0992
- Date: 2021-05
- Subjects: Pentecostalism , Religion and sociology
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21167 , vital:47216
- Description: Pentecostalism has spread rapidly worldwide and continues to do so, thereby generating scholarly interest on how much church growth was attained through marketing. In Zimbabwe, it is evident that marketing communication has become an essential part of church activities to attract the society. In the case of Pentecostal churches, both church and marketing activities are interrelated, as seen through the increased usage of digital communication marketing strategies to attract followers, especially on social media. With effective marketing, people can be attached to a church, in the same way, they would be attached to a brand. In this regard, this study therefore examined whether fundamental marketing principles apply to the marketing of Pentecostal religiosity in Zimbabwe - focusing on how the churches, church services or products, and prophets are marketed. The study also explored how such church marketing attributes to the popularity of these churches and how ultimately the church marketing communication affects society. Theoretically, Pentecostal churches can utilise Porter’s Five Forces, Marketing Communication Mix, and AIDA Model to maintain a favourable marketing standing. With the presence of communication technologies and the media, the applicability of these marketing theories is effortless, hence the marketing of Pentecostal churches has flourished. This study used a qualitative research design and was conducted on three Pentecostal churches namely the Prophetic Healing and Deliverance Ministries, United Family International Church, and Spirit Embassy (The Good News Church) in Harare, Zimbabwe. The data was gathered from the churches’ Facebook pages, websites, and newspaper articles reporting about the churches. In addition, interviews with church marketing personnel from each church, 30 church members and focus group interviews with 30 non-church members residing close to the Pentecostal churches were conducted. The findings reveal that the Pentecostal churches in Zimbabwe are actively involved in church marketing and have various marketing strategies as any business entity would. However, the churches’ image and efforts aimed at fulfilling social mandates are tainted by several marketing strategies which are used, especially on digital media. In addition, church marketing has promoted commercialised religion and the Pentecostal fraternity is certainly morphing into businesses at the expense of spirituality and religiosity, which is simply an epitome of secularising the sacred. Furthermore, it was established that the marketing strategies used are influential to target markets, such as church members, and the effects are adverse. Hence, this study recommends regulation of Pentecostal churches and proposes three models that illustrate regulation at government level, collective level, and individual level through policy regulation, collective action, and self-regulation respectively. This will encourage churches to conduct ethical church marketing and protect religious consumers. , Thesis (PhD) -- Faculty of Social Science and Humanities, 2021
- Full Text:
- Date Issued: 2021-05
Modelling internet network intrusion detection in smart city ecosystems
- Authors: Mfenguza, Wandisa
- Date: 2021-05
- Subjects: Ecosystem management , Smart cities
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22501 , vital:52382
- Description: Smart city systems are intended to enhance the lives of citizens through the design of systems that promote resource efficiency and the real-time provisioning of resources in cities. The benefits offered by smart cities include the use of internet of things (IoT) sensors to gather useful data such as power demand to inhibit blackouts and the average speed of vehicles to alleviate traffic congestion. Nonetheless, earlier studies have indicated a substantial increase in cyber-security issues due to the increase in the deployment of smart city ecosystems. Consequently, IoT cyber-security is recognised as an area that requires crucial scrutiny. This study begins by investigating the current state of intrusion detection in smart city ecosystems. Current intrusion detection frameworks lack the capability to operate under extremely limiting settings such as conditions of low processing power and fast response times. Moreover, the study also identifies that, despite intrusion detection being a highly researched thematic area, a plethora of previous studies tend to propose intrusion detection frameworks that are more suitable for traditional computer networks rather than wireless sensor networks (WSNs) which consist of heterogeneous settings with diverse devices and communication protocols. Subsequently, this study developed two candidate deep learning models, namely a convolutional neural network (CNN) and a long short-term memory (LSTM) network and presents evidence on their robustness and predictive power. Results have indicated that, unlike the CNN model, the LSTM model can quickly converge and offer high predictive power without the vigorous application of regularisation techniques. The proposed LSTM classification model obtained a remarkable 100% in detection rates and further reported 0% in false alarm and false negative rates. This study gives a broad overview of the current state of intrusion detection mechanisms for smart city ecosystems to guide future studies. The study also demonstrates that existing intrusion detection systems (IDSs) can be enhanced through the development of more robust and lightweight models that offer high detection rates and minimal false alarm rates to prevent security risks in smart city ecosystems to ensure sustainable and safe smart cities. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Mfenguza, Wandisa
- Date: 2021-05
- Subjects: Ecosystem management , Smart cities
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22501 , vital:52382
- Description: Smart city systems are intended to enhance the lives of citizens through the design of systems that promote resource efficiency and the real-time provisioning of resources in cities. The benefits offered by smart cities include the use of internet of things (IoT) sensors to gather useful data such as power demand to inhibit blackouts and the average speed of vehicles to alleviate traffic congestion. Nonetheless, earlier studies have indicated a substantial increase in cyber-security issues due to the increase in the deployment of smart city ecosystems. Consequently, IoT cyber-security is recognised as an area that requires crucial scrutiny. This study begins by investigating the current state of intrusion detection in smart city ecosystems. Current intrusion detection frameworks lack the capability to operate under extremely limiting settings such as conditions of low processing power and fast response times. Moreover, the study also identifies that, despite intrusion detection being a highly researched thematic area, a plethora of previous studies tend to propose intrusion detection frameworks that are more suitable for traditional computer networks rather than wireless sensor networks (WSNs) which consist of heterogeneous settings with diverse devices and communication protocols. Subsequently, this study developed two candidate deep learning models, namely a convolutional neural network (CNN) and a long short-term memory (LSTM) network and presents evidence on their robustness and predictive power. Results have indicated that, unlike the CNN model, the LSTM model can quickly converge and offer high predictive power without the vigorous application of regularisation techniques. The proposed LSTM classification model obtained a remarkable 100% in detection rates and further reported 0% in false alarm and false negative rates. This study gives a broad overview of the current state of intrusion detection mechanisms for smart city ecosystems to guide future studies. The study also demonstrates that existing intrusion detection systems (IDSs) can be enhanced through the development of more robust and lightweight models that offer high detection rates and minimal false alarm rates to prevent security risks in smart city ecosystems to ensure sustainable and safe smart cities. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
Raising a child with an intellectual disability in a township: The lived experiences of black South African parents
- Authors: Sothoane, Relebogile Happy
- Date: 2021-05
- Subjects: Intelligence levels , Intellectual disability , Developmental disabilities
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23238 , vital:56483
- Description: This study was conducted to explore and understand how black South African parents residing in a township, experience raising a child with an intellectual disability. It was important to investigate this under-researched phenomenon to have a holistic understanding of the personal experiences and meanings that black South African parents have over the years attached to, and experienced in their journeys of raising a child with intellectual impairments in low economic areas. An Interpretive qualitative approach was adopted to explore and understand the experiences of raising a child with an intellectual disability in a township by black South African parents. Non-probability snowball and purposive sampling methods were used to develop the sample for this study. Four parents residing in two townships (Mdantsane and Ducan Village) around the Buffalo City Municipality which is situated in the Eastern Cape province participated in this study. Data was collected through personal, face to face and individual interviews which were audio-recorded and transcribed verbatim. Braun and Clarke’s six steps of thematic analysis was employed to analyse the data that was collected. The results of this study showed that raising children with intellectual disabilities in a township is challenging. Parents tend to feel that they are alone on this journey because of the lack of support, acceptance and understanding they receive from family members, the community and even teachers. Furthermore, the study found that being financially disadvantaged is a challenge when it comes to raising a child with an intellectual disability. Participants in this study indicated that the unconditional love they have for their children motivates them daily to raise their children and that they have hopes and dreams for their children despite the children’s impairments. This study recommends that the department of education hold more psychoeducation workshops on intellectual disability, especially for teachers in mainstream and inclusive schools who educate children with intellectual disabilities. Furthermore, more awareness campaigns in townships to educate the community on intellectual disability are recommended. , Thesis (MSoc Sci) (Counselling Psychology) --Faculty of Social Science and Humanities, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Sothoane, Relebogile Happy
- Date: 2021-05
- Subjects: Intelligence levels , Intellectual disability , Developmental disabilities
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23238 , vital:56483
- Description: This study was conducted to explore and understand how black South African parents residing in a township, experience raising a child with an intellectual disability. It was important to investigate this under-researched phenomenon to have a holistic understanding of the personal experiences and meanings that black South African parents have over the years attached to, and experienced in their journeys of raising a child with intellectual impairments in low economic areas. An Interpretive qualitative approach was adopted to explore and understand the experiences of raising a child with an intellectual disability in a township by black South African parents. Non-probability snowball and purposive sampling methods were used to develop the sample for this study. Four parents residing in two townships (Mdantsane and Ducan Village) around the Buffalo City Municipality which is situated in the Eastern Cape province participated in this study. Data was collected through personal, face to face and individual interviews which were audio-recorded and transcribed verbatim. Braun and Clarke’s six steps of thematic analysis was employed to analyse the data that was collected. The results of this study showed that raising children with intellectual disabilities in a township is challenging. Parents tend to feel that they are alone on this journey because of the lack of support, acceptance and understanding they receive from family members, the community and even teachers. Furthermore, the study found that being financially disadvantaged is a challenge when it comes to raising a child with an intellectual disability. Participants in this study indicated that the unconditional love they have for their children motivates them daily to raise their children and that they have hopes and dreams for their children despite the children’s impairments. This study recommends that the department of education hold more psychoeducation workshops on intellectual disability, especially for teachers in mainstream and inclusive schools who educate children with intellectual disabilities. Furthermore, more awareness campaigns in townships to educate the community on intellectual disability are recommended. , Thesis (MSoc Sci) (Counselling Psychology) --Faculty of Social Science and Humanities, 2021
- Full Text:
- Date Issued: 2021-05
Sedimentology, reservoir properties and hydrocarbon potential of the southern Bredasdorp Basin, offshore of the Western Cape Province, South Africa
- Authors: Baiyegunhi, Temitope Love
- Date: 2021-05
- Subjects: Sediments (Geology) , Hydrocarbon reservoirs
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20753 , vital:46546
- Description: The Bredasdorp Basin has become the focus for exploration activity (i.e., seismic exploration and drilling) since the discovery of gas-condensate and oil reservoirs in the early 1980s. The basin has proven hydrocarbon reserves and potential for future discoveries. However, uncertainty about the sedimentological and petrographic characteristics, reservoir qualities, thermal maturity and hydrocarbon potential of the source/reservoir rocks has hindered further exploration, particularly in the southern part of the basin. To date, this part of the basin remains unexplored and partially understood with respect to petroleum systems evolution when compared to the central and northern parts of the basin. To fill the research gaps, exploration wells E-AH1, E-AJ1, E-BA1, E-BB1 and E-D3 were investigated so as to unravel the petrographic characteristics, depositional processes and paleoenvironment, tectonic provenance, paleoweathering, hydrocarbon potential, thermal maturity, diagenetic characterisitcs and reservoir qualities of the southern Bredasdorp Basin. The grain size textural parameters revealed that the southern Bredasdorp Basin sandstones are unimodal, predominantly fine-grained, moderately well sorted, mesokurtic and near-symmetrical. The bivariate plots of grain size textural parameters indicate that the depositional environments had been influenced mainly by river/beach/coastal dune conditions. The linear discriminate functions (LDF) diagrams show that the sediments are turbidity current deposits in a shallow marine environment. The Passega diagram revealed that the studied sandstones were mainly deposited by traction currents and beach process. In addition, the grain size log-probability curves and Passega diagram show the predominance of saltation and suspension modes of sediment transportation. Based on the inter-relationship of the various statistical parameters, it is deduced that the southern Bredasdorp Basin are mainly shallow marine deposits with signature of beach and coastal river processes. Based on the lithofacies analysis of the southern Bredasdorp Basin borehole cores, thirteen lithofacies were identified and grouped into six facies associations (FAs). The facies associations are: matrix supported conglomerate and massive sandstone (FA 1), ripple cross laminated, trough cross bedded and bioturbated sandstone (FA 2), massive sandstone with mudstone and shale interbeds (FA 3), alternating laminated to interbedded sandstone/siltstone and mudstone (FA 4), massive mudstone with minor interlamination of clay-rich sandstones and siltstone (FA 5), and carbonaceous laminated shale and mudstone with occasional siltstone laminae (FA 6). Facies associations FA1, FA2, FA3, FA4, FA5 and FA6 are interpreted as submarine channel-fills, submarine channel-levee, submarine sheet lobe, submarine lobe fring/overflow, basin plain deposits and deep sea floor/basin plain deposits, respectively. Sedimentological evidences from lithofacies interpretation revealed shallow marine environment as the main depositional environment, with minor contribution from the deep marine environment. Petrographic studies show that the southern Bredasdorp Basin sandstones chiefly consist of quartz (52.2–68.0percent), feldspar (10.0–18.0percent), and lithic fragments (5.0–10.2percent). The modal composition analysis revealed that the sandstones could be classified as subarkosic arenite and lithic arkose. The provenance ternary diagrams revealed that the rocks are mainly of continental block provenances (stable shields and basement uplifted areas) and complemented by recycled sands from an associated platform. The tectonic provenance studies show that the sandstones are typically rift-derived arenites and have undergone long-distance transport from the source area along the rift. In the regional context of the evolution of the Bredasdorp Basin, the results suggested that the basin developed on a passive rift setting (trailing edge) of the stable continental margins. The provenance discrimination diagrams based on major oxide geochemistry revealed that the sandstones are mainly of quartzose sedimentary provenance, while the mudrocks are of quartzose sedimentary and intermediate igneous provenances. The discrimination diagrams indicate that the southern Bredasdorp Basin sediments were mostly derived from a cratonic interior or recycled orogen. The bivariate plots of TiO2 versus Ni, TiO2 against Zr and La/Th versus Hf as well as the ternary diagrams of V–Ni–Th×10 suggest that the mudrocks and sandstones were derived from felsic igneous rocks. The tectonic setting discrimination diagrams support passive-active continental margin setting of the provenance. Chemical index of alteration (CIA) indices observed in the sandstones suggest that their source area underwent low to moderate degree of chemical weathering. However, the mudrocks have high CIA indices suggesting that the source area underwent more intense chemical weathering, possibly due to climatic and/or tectonic variations. The organic geochemistry results show that these rocks have total organic carbon, TOC contents ranging from 0.14 to 7.03 wt.percent. The hydrogen index (HI), oxygen index (OI), and hydrocarbon index (S2/S3) values vary between 24–263 mg HC/g TOC, 4–78 mg CO2/g TOC, and 0.01–18 mgHC/mgCO2 TOC, respectively, indicating predominantly Type III and IV kerogen with a minor amount of mixed Type II/III kerogen. The mean vitrinite reflectance values vary from 0.60–1.20percent, indicating that the samples are in the oil-generation window. The Tmax and PI values are consistent with the mean vitrinite reflectance values, indicating that the southern Bredasdorp Basin source rocks have entered the oil window and are considered as effective source rocks in the southern Bredasdorp Basin. The hydrocarbon genetic potential (SP), normalized oil content (NOC) and production index (PI) values all indicate poor to fair hydrocarbon generative potential. The main diagenetic processes that have affected the reservoir quality of the southern Bredasdorp Basin rocks are cementation by authigenic clay, carbonate and silica, growth of authigenic glauconite, dissolution of minerals and load compaction. These aforementioned diagenetic processes act differently in each borehole and at different depths. The influence of cementation and compaction is complex with no particular pattern with increasing depth, suggesting that diagenesis is the main challenge to reservoir characterization in the southern Bredasdorp Basin. The clays in the sandstones act as pore choking cement, which reduces porosity and permeability of the reservoir rocks. Reservoir quality of the sandstones has been improved to various extents due to the development of secondary porosity as a result of partial to complete dissolution of early calcite cement and some detrital grains (feldspars) and also affected by grain fracturing. The scattered plots of porosity and permeability versus cement+clays show good inverse correlations, suggesting that the reservoir quality is mainly controlled by cementation and authigenic clays. Based on the diagenetic study, it can be inferred that the potential reservoir quality of the southern Bredasdorp Basin sandstones is poor-moderate. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Baiyegunhi, Temitope Love
- Date: 2021-05
- Subjects: Sediments (Geology) , Hydrocarbon reservoirs
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20753 , vital:46546
- Description: The Bredasdorp Basin has become the focus for exploration activity (i.e., seismic exploration and drilling) since the discovery of gas-condensate and oil reservoirs in the early 1980s. The basin has proven hydrocarbon reserves and potential for future discoveries. However, uncertainty about the sedimentological and petrographic characteristics, reservoir qualities, thermal maturity and hydrocarbon potential of the source/reservoir rocks has hindered further exploration, particularly in the southern part of the basin. To date, this part of the basin remains unexplored and partially understood with respect to petroleum systems evolution when compared to the central and northern parts of the basin. To fill the research gaps, exploration wells E-AH1, E-AJ1, E-BA1, E-BB1 and E-D3 were investigated so as to unravel the petrographic characteristics, depositional processes and paleoenvironment, tectonic provenance, paleoweathering, hydrocarbon potential, thermal maturity, diagenetic characterisitcs and reservoir qualities of the southern Bredasdorp Basin. The grain size textural parameters revealed that the southern Bredasdorp Basin sandstones are unimodal, predominantly fine-grained, moderately well sorted, mesokurtic and near-symmetrical. The bivariate plots of grain size textural parameters indicate that the depositional environments had been influenced mainly by river/beach/coastal dune conditions. The linear discriminate functions (LDF) diagrams show that the sediments are turbidity current deposits in a shallow marine environment. The Passega diagram revealed that the studied sandstones were mainly deposited by traction currents and beach process. In addition, the grain size log-probability curves and Passega diagram show the predominance of saltation and suspension modes of sediment transportation. Based on the inter-relationship of the various statistical parameters, it is deduced that the southern Bredasdorp Basin are mainly shallow marine deposits with signature of beach and coastal river processes. Based on the lithofacies analysis of the southern Bredasdorp Basin borehole cores, thirteen lithofacies were identified and grouped into six facies associations (FAs). The facies associations are: matrix supported conglomerate and massive sandstone (FA 1), ripple cross laminated, trough cross bedded and bioturbated sandstone (FA 2), massive sandstone with mudstone and shale interbeds (FA 3), alternating laminated to interbedded sandstone/siltstone and mudstone (FA 4), massive mudstone with minor interlamination of clay-rich sandstones and siltstone (FA 5), and carbonaceous laminated shale and mudstone with occasional siltstone laminae (FA 6). Facies associations FA1, FA2, FA3, FA4, FA5 and FA6 are interpreted as submarine channel-fills, submarine channel-levee, submarine sheet lobe, submarine lobe fring/overflow, basin plain deposits and deep sea floor/basin plain deposits, respectively. Sedimentological evidences from lithofacies interpretation revealed shallow marine environment as the main depositional environment, with minor contribution from the deep marine environment. Petrographic studies show that the southern Bredasdorp Basin sandstones chiefly consist of quartz (52.2–68.0percent), feldspar (10.0–18.0percent), and lithic fragments (5.0–10.2percent). The modal composition analysis revealed that the sandstones could be classified as subarkosic arenite and lithic arkose. The provenance ternary diagrams revealed that the rocks are mainly of continental block provenances (stable shields and basement uplifted areas) and complemented by recycled sands from an associated platform. The tectonic provenance studies show that the sandstones are typically rift-derived arenites and have undergone long-distance transport from the source area along the rift. In the regional context of the evolution of the Bredasdorp Basin, the results suggested that the basin developed on a passive rift setting (trailing edge) of the stable continental margins. The provenance discrimination diagrams based on major oxide geochemistry revealed that the sandstones are mainly of quartzose sedimentary provenance, while the mudrocks are of quartzose sedimentary and intermediate igneous provenances. The discrimination diagrams indicate that the southern Bredasdorp Basin sediments were mostly derived from a cratonic interior or recycled orogen. The bivariate plots of TiO2 versus Ni, TiO2 against Zr and La/Th versus Hf as well as the ternary diagrams of V–Ni–Th×10 suggest that the mudrocks and sandstones were derived from felsic igneous rocks. The tectonic setting discrimination diagrams support passive-active continental margin setting of the provenance. Chemical index of alteration (CIA) indices observed in the sandstones suggest that their source area underwent low to moderate degree of chemical weathering. However, the mudrocks have high CIA indices suggesting that the source area underwent more intense chemical weathering, possibly due to climatic and/or tectonic variations. The organic geochemistry results show that these rocks have total organic carbon, TOC contents ranging from 0.14 to 7.03 wt.percent. The hydrogen index (HI), oxygen index (OI), and hydrocarbon index (S2/S3) values vary between 24–263 mg HC/g TOC, 4–78 mg CO2/g TOC, and 0.01–18 mgHC/mgCO2 TOC, respectively, indicating predominantly Type III and IV kerogen with a minor amount of mixed Type II/III kerogen. The mean vitrinite reflectance values vary from 0.60–1.20percent, indicating that the samples are in the oil-generation window. The Tmax and PI values are consistent with the mean vitrinite reflectance values, indicating that the southern Bredasdorp Basin source rocks have entered the oil window and are considered as effective source rocks in the southern Bredasdorp Basin. The hydrocarbon genetic potential (SP), normalized oil content (NOC) and production index (PI) values all indicate poor to fair hydrocarbon generative potential. The main diagenetic processes that have affected the reservoir quality of the southern Bredasdorp Basin rocks are cementation by authigenic clay, carbonate and silica, growth of authigenic glauconite, dissolution of minerals and load compaction. These aforementioned diagenetic processes act differently in each borehole and at different depths. The influence of cementation and compaction is complex with no particular pattern with increasing depth, suggesting that diagenesis is the main challenge to reservoir characterization in the southern Bredasdorp Basin. The clays in the sandstones act as pore choking cement, which reduces porosity and permeability of the reservoir rocks. Reservoir quality of the sandstones has been improved to various extents due to the development of secondary porosity as a result of partial to complete dissolution of early calcite cement and some detrital grains (feldspars) and also affected by grain fracturing. The scattered plots of porosity and permeability versus cement+clays show good inverse correlations, suggesting that the reservoir quality is mainly controlled by cementation and authigenic clays. Based on the diagenetic study, it can be inferred that the potential reservoir quality of the southern Bredasdorp Basin sandstones is poor-moderate. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05