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The use of the cochineal insect, Dactylopius tomentosus Lamarck, as a biological control agent for the invasive alien thistle cholla, Cylindropuntia pallida (Rose) F.M. Knuth in South Africa
- Authors: Zozo, Ekhona
- Date: 2022-04-06
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/233823 , vital:50131
- Description: Cylindropuntia pallida (Rose) F.M. Knuth (Cactaceae) is an invasive alien plant in South Africa indigenous in the southern U.S.A. and Mexico. Large infestations of this species can be found in the Kalahari and arid Karoo regions of South Africa, which is also present in Namibia. Because it is a very spiny cactus, dense infestations have a negative impact on agriculture and natural ecosystems. This cactus has become naturalised to the extent that eradication is impossible and the negative impacts are steadily increasing due to its increasing distribution and density. The cochineal insect, Dactylopius tomentosus Lamarck (Dactylopiidae), is native in Mexico and parts of North America, such as Texas, Arizona, and New Mexico in the U.S.A. This cochineal species is highly specialized and associated only with Cylindropuntia species, a group of cacti that are primarily restricted to the same areas. It has been introduced into Australia and South Africa as a biological control agent to control various invasive alien Cylindropuntia species. This cochineal species has several biotypes specific to certain Cylindropuntia species hosts. A biotype is a clade that cannot be differentiated morphologically from others but has different host ranges and impacts depending on the host plant species. Included amongst biotypes that have been released in South Africa are D. tomentosus ‘imbricata’ and D. tomentosus ‘cholla’ for the biological control of Cylindropuntia imbricata (Haw.) F.M. Knuth (Cactaceae) and Cylindropuntia fulgida (Engelmann) F.M. Knuth var. mamillata (Schott ex Engelmann) Backeb. (Cactaceae), respectively. These biotypes have resulted in both host plants being under substantial control in South Africa. The first part of this thesis evaluated which of the two D. tomentosus biotypes already in use in South Africa could be an effective biological control agent for C. pallida. This was done by assessing the fitness of the cochineals on the three cactus species and assessing the impact that each of the cochineals has on each of the target weed species. Should these biotypes prove ineffective, there is a third biotype, namely D. tomentosus ‘californica var. parkerii’, which researchers in Australia have worked on and have found to be suitably host-specific for release in Australia and suitably damaging to C. pallida in that country. Therefore, this new biotype could be released in South Africa if it is required. Sexually compatible biological control agents, especially those closely related and occurring in close spatial proximity to one another, may interbreed and the impacts of this hybridisation are difficult to predict. It is important to understand the outcomes of the hybridisation of cochineal because it can affect the impact of the biological control agents and thus the control of the target weed. The second part of this thesis investigated the impacts of the hybridisation of the two cochineal biotypes by assessing the damage the agents would have on the target weed, and on C. imbricata and C. fulgida var. mamillata, in the presence of one or both cochineal biotypes. The ‘cholla’ biotype performed better on C. pallida than the ‘imbricata’ biotype, but neither biotype could control C. pallida to an extent similar to the control they provide for their respective target weeds, C. imbricata and C. fulgida var. mamillata. Both the ‘cholla’ biotype and hybrids of the two biotypes of cochineal were effective at killing C. pallida when both C. imbricata and C. fulgida var. mamillata were also present. This suggests that the ‘cholla’ or hybrids may be effective at controlling C. pallida when either C. imbricata or C. fulgida var. mamillata are also present in the field due to the high population density of cochineal that results under these circumstances. There are, however, many C. pallida infestations in South Africa where the plant is problematic and is isolated from other Cylindropuntia species, and these populations are unlikely to be controlled by the ‘cholla’ biotype or the hybrids. Neither of the cochineal biotypes that are used for biological control in South Africa are suitably damaging to C. pallida to warrant their use as biological control agents for this species. Dactylopius tomentosus ‘californica var. parkerii’ is therefore recommended for release based on its host-specificity and impact to C. pallida in Australia. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Zozo, Ekhona
- Date: 2022-04-06
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/233823 , vital:50131
- Description: Cylindropuntia pallida (Rose) F.M. Knuth (Cactaceae) is an invasive alien plant in South Africa indigenous in the southern U.S.A. and Mexico. Large infestations of this species can be found in the Kalahari and arid Karoo regions of South Africa, which is also present in Namibia. Because it is a very spiny cactus, dense infestations have a negative impact on agriculture and natural ecosystems. This cactus has become naturalised to the extent that eradication is impossible and the negative impacts are steadily increasing due to its increasing distribution and density. The cochineal insect, Dactylopius tomentosus Lamarck (Dactylopiidae), is native in Mexico and parts of North America, such as Texas, Arizona, and New Mexico in the U.S.A. This cochineal species is highly specialized and associated only with Cylindropuntia species, a group of cacti that are primarily restricted to the same areas. It has been introduced into Australia and South Africa as a biological control agent to control various invasive alien Cylindropuntia species. This cochineal species has several biotypes specific to certain Cylindropuntia species hosts. A biotype is a clade that cannot be differentiated morphologically from others but has different host ranges and impacts depending on the host plant species. Included amongst biotypes that have been released in South Africa are D. tomentosus ‘imbricata’ and D. tomentosus ‘cholla’ for the biological control of Cylindropuntia imbricata (Haw.) F.M. Knuth (Cactaceae) and Cylindropuntia fulgida (Engelmann) F.M. Knuth var. mamillata (Schott ex Engelmann) Backeb. (Cactaceae), respectively. These biotypes have resulted in both host plants being under substantial control in South Africa. The first part of this thesis evaluated which of the two D. tomentosus biotypes already in use in South Africa could be an effective biological control agent for C. pallida. This was done by assessing the fitness of the cochineals on the three cactus species and assessing the impact that each of the cochineals has on each of the target weed species. Should these biotypes prove ineffective, there is a third biotype, namely D. tomentosus ‘californica var. parkerii’, which researchers in Australia have worked on and have found to be suitably host-specific for release in Australia and suitably damaging to C. pallida in that country. Therefore, this new biotype could be released in South Africa if it is required. Sexually compatible biological control agents, especially those closely related and occurring in close spatial proximity to one another, may interbreed and the impacts of this hybridisation are difficult to predict. It is important to understand the outcomes of the hybridisation of cochineal because it can affect the impact of the biological control agents and thus the control of the target weed. The second part of this thesis investigated the impacts of the hybridisation of the two cochineal biotypes by assessing the damage the agents would have on the target weed, and on C. imbricata and C. fulgida var. mamillata, in the presence of one or both cochineal biotypes. The ‘cholla’ biotype performed better on C. pallida than the ‘imbricata’ biotype, but neither biotype could control C. pallida to an extent similar to the control they provide for their respective target weeds, C. imbricata and C. fulgida var. mamillata. Both the ‘cholla’ biotype and hybrids of the two biotypes of cochineal were effective at killing C. pallida when both C. imbricata and C. fulgida var. mamillata were also present. This suggests that the ‘cholla’ or hybrids may be effective at controlling C. pallida when either C. imbricata or C. fulgida var. mamillata are also present in the field due to the high population density of cochineal that results under these circumstances. There are, however, many C. pallida infestations in South Africa where the plant is problematic and is isolated from other Cylindropuntia species, and these populations are unlikely to be controlled by the ‘cholla’ biotype or the hybrids. Neither of the cochineal biotypes that are used for biological control in South Africa are suitably damaging to C. pallida to warrant their use as biological control agents for this species. Dactylopius tomentosus ‘californica var. parkerii’ is therefore recommended for release based on its host-specificity and impact to C. pallida in Australia. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-04-06
A framework for guiding the interdisciplinary design of mHealth intervention apps for physical activity behaviour change
- Authors: Thomson, Callie Deborah
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/232193 , vital:49970 , DOI http://doi.org/10.21504/10962/232193
- Description: The global pandemic of noncommunicable diseases and its associated premature mortality rates and socioeconomic burden have led to increasingly intensified efforts towards designing and delivering health promotion interventions aimed at addressing the leading modifiable health risk behaviours, such as physical inactivity. Developing physical activity behaviour change interventions that target individuals at the dual intra-interpersonal socioecological levels of health promotion has become a key objective worldwide. Digital and mobile technology is revolutionising the ways in which health behaviour change interventions are delivered to individuals across the world, with mobile health applications (mHealth apps) increasingly recognised as a powerful means of promoting physical activity behaviour change. However, with the growth and opportunities of mHealth apps, come several design challenges. Key design challenges concern the integration of theory, the incorporation of evidence-based behaviour change techniques, the application of persuasive systems design principles, and the importance of multi- and interdisciplinary collaborative design, development and evaluation approaches. These key challenges influence the output product design and effectiveness of mHealth physical activity behaviour change intervention apps. There exists a paucity of approaches for guiding and supporting the multi- and interdisciplinary collaborative design, development and evaluation of mHealth physical activity behaviour change intervention apps. To address this gap, this research study proposes an Interdisciplinary mHealth App Design Framework, framed by a novel boundary object view. This view considers the diverse communities of practice, boundary objects and supporting artefacts, process activities, and knowledge sharing practices necessary and relevant to the design of effective mHealth physical activity behaviour change intervention apps. The framework’s development is guided by a Design Science Research (DSR) approach. Its core components are based on the findings of a critical theoretical analysis of twenty existing multi- and interdisciplinary digital health development approaches. Once developed, the framework is evaluated using a qualitative DSR linguistic interpretivist approach, with semi-structured interviews as the research instrument. The thematic analysis findings from interviews with thirty-one international academic researchers and industry practitioners informs the iterative modification and revision of an enhanced Interdisciplinary mHealth App Design Framework, constituting the main DSR artefact contribution of the research study. In addition, four theoretical contributions are made to the mHealth intervention app design body of knowledge, and a practical contribution is made through the provision of guideline recommendations for academics and industry practitioners. Methodological contributions are also made in terms of applying DSR, adopting a hybrid cognitive reasoning strategy, and employing a qualitative linguistic interpretivist approach to evaluation within a DSR project. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Thomson, Callie Deborah
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/232193 , vital:49970 , DOI http://doi.org/10.21504/10962/232193
- Description: The global pandemic of noncommunicable diseases and its associated premature mortality rates and socioeconomic burden have led to increasingly intensified efforts towards designing and delivering health promotion interventions aimed at addressing the leading modifiable health risk behaviours, such as physical inactivity. Developing physical activity behaviour change interventions that target individuals at the dual intra-interpersonal socioecological levels of health promotion has become a key objective worldwide. Digital and mobile technology is revolutionising the ways in which health behaviour change interventions are delivered to individuals across the world, with mobile health applications (mHealth apps) increasingly recognised as a powerful means of promoting physical activity behaviour change. However, with the growth and opportunities of mHealth apps, come several design challenges. Key design challenges concern the integration of theory, the incorporation of evidence-based behaviour change techniques, the application of persuasive systems design principles, and the importance of multi- and interdisciplinary collaborative design, development and evaluation approaches. These key challenges influence the output product design and effectiveness of mHealth physical activity behaviour change intervention apps. There exists a paucity of approaches for guiding and supporting the multi- and interdisciplinary collaborative design, development and evaluation of mHealth physical activity behaviour change intervention apps. To address this gap, this research study proposes an Interdisciplinary mHealth App Design Framework, framed by a novel boundary object view. This view considers the diverse communities of practice, boundary objects and supporting artefacts, process activities, and knowledge sharing practices necessary and relevant to the design of effective mHealth physical activity behaviour change intervention apps. The framework’s development is guided by a Design Science Research (DSR) approach. Its core components are based on the findings of a critical theoretical analysis of twenty existing multi- and interdisciplinary digital health development approaches. Once developed, the framework is evaluated using a qualitative DSR linguistic interpretivist approach, with semi-structured interviews as the research instrument. The thematic analysis findings from interviews with thirty-one international academic researchers and industry practitioners informs the iterative modification and revision of an enhanced Interdisciplinary mHealth App Design Framework, constituting the main DSR artefact contribution of the research study. In addition, four theoretical contributions are made to the mHealth intervention app design body of knowledge, and a practical contribution is made through the provision of guideline recommendations for academics and industry practitioners. Methodological contributions are also made in terms of applying DSR, adopting a hybrid cognitive reasoning strategy, and employing a qualitative linguistic interpretivist approach to evaluation within a DSR project. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2022
- Full Text:
- Date Issued: 2022-04
A multispectral and machine learning approach to early stress classification in plants
- Authors: Poole, Louise Carmen
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232410 , vital:49989
- Description: Crop loss and failure can impact both a country’s economy and food security, often to devastating effects. As such, the importance of successfully detecting plant stresses early in their development is essential to minimize spread and damage to crop production. Identification of the stress and the stress-causing agent is the most critical and challenging step in plant and crop protection. With the development of and increase in ease of access to new equipment and technology in recent years, the use of spectroscopy in the early detection of plant diseases has become notably popular. This thesis narrows down the most suitable multispectral imaging techniques and machine learning algorithms for early stress detection. Datasets were collected of visible images and multispectral images. Dehydration was selected as the plant stress type for the main experiments, and data was collected from six plant species typically used in agriculture. Key contributions of this thesis include multispectral and visible datasets showing plant dehydration as well as a separate preliminary dataset on plant disease. Promising results on dehydration showed statistically significant accuracy improvements in the multispectral imaging compared to visible imaging for early stress detection, with multispectral input obtaining a 92.50% accuracy over visible input’s 77.50% on general plant species. The system was effective at stress detection on known plant species, with multispectral imaging introducing greater improvement to early stress detection than advanced stress detection. Furthermore, strong species discrimination was achieved when exclusively testing either early or advanced dehydration against healthy species. , Thesis (MSc) -- Faculty of Science, Ichthyology & Fisheries Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Poole, Louise Carmen
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232410 , vital:49989
- Description: Crop loss and failure can impact both a country’s economy and food security, often to devastating effects. As such, the importance of successfully detecting plant stresses early in their development is essential to minimize spread and damage to crop production. Identification of the stress and the stress-causing agent is the most critical and challenging step in plant and crop protection. With the development of and increase in ease of access to new equipment and technology in recent years, the use of spectroscopy in the early detection of plant diseases has become notably popular. This thesis narrows down the most suitable multispectral imaging techniques and machine learning algorithms for early stress detection. Datasets were collected of visible images and multispectral images. Dehydration was selected as the plant stress type for the main experiments, and data was collected from six plant species typically used in agriculture. Key contributions of this thesis include multispectral and visible datasets showing plant dehydration as well as a separate preliminary dataset on plant disease. Promising results on dehydration showed statistically significant accuracy improvements in the multispectral imaging compared to visible imaging for early stress detection, with multispectral input obtaining a 92.50% accuracy over visible input’s 77.50% on general plant species. The system was effective at stress detection on known plant species, with multispectral imaging introducing greater improvement to early stress detection than advanced stress detection. Furthermore, strong species discrimination was achieved when exclusively testing either early or advanced dehydration against healthy species. , Thesis (MSc) -- Faculty of Science, Ichthyology & Fisheries Sciences, 2022
- Full Text:
- Date Issued: 2022-04
A Smaller Circle
- Authors: Bhikha, Nasira
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232427 , vital:49991
- Description: My thesis is a collection of prose forms weaving my identity as a South African woman of colour, my observations of life through personal, cultural and sociological lenses, where traditions are constantly challenged and evolving. The collection focuses on the untold and unresolved, using fiction as a tool of pushback and psychological reflection. I am motivated by writers who use what I would term reflective expressionism to evoke empathy by tapping into innate, universal emotions. In particular Tiff Holland’s vivid telling of family in the novella Betty Superman where she navigates complex relationships, and bell hooks’ memoirs Bone Black: Memories of Girlhood written as poetic vignettes in fluctuating points of view to draw attention to the intricacies of social structures. Joanna Walsh’s Vertigo has strongly influenced my approach to writing through her compelling imagery and use of motif in fragmented prose that delves into the psyche of her characters. I am also inspired by Lidia Yuknavitch’s visceral use of language, identifying with her invitation: “You deserve to sit at the table. The radiance falls on all of us.” , Thesis (MACW) -- Faculty of Humanities, School of Languages, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Bhikha, Nasira
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232427 , vital:49991
- Description: My thesis is a collection of prose forms weaving my identity as a South African woman of colour, my observations of life through personal, cultural and sociological lenses, where traditions are constantly challenged and evolving. The collection focuses on the untold and unresolved, using fiction as a tool of pushback and psychological reflection. I am motivated by writers who use what I would term reflective expressionism to evoke empathy by tapping into innate, universal emotions. In particular Tiff Holland’s vivid telling of family in the novella Betty Superman where she navigates complex relationships, and bell hooks’ memoirs Bone Black: Memories of Girlhood written as poetic vignettes in fluctuating points of view to draw attention to the intricacies of social structures. Joanna Walsh’s Vertigo has strongly influenced my approach to writing through her compelling imagery and use of motif in fragmented prose that delves into the psyche of her characters. I am also inspired by Lidia Yuknavitch’s visceral use of language, identifying with her invitation: “You deserve to sit at the table. The radiance falls on all of us.” , Thesis (MACW) -- Faculty of Humanities, School of Languages, 2022
- Full Text:
- Date Issued: 2022-04
Adolescents and coaches/trainers perspectives of ergogenic sports supplement use within South African private high schools
- Authors: Butler, Nicholas John
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232443 , vital:49992
- Description: Sports supplements, also referred to as ergogenic aids, are used because of the assertion that they can enhance physical or athletic performance and/or physical appearance. Commonly used sports supplements include creatines, proteins, amino acids, stimulants, and in some cases pro-hormones. There is a relatively high and increasing prevalence of sports supplement use by the general population globally and in South Africa, particularly among adolescents and young adults due to various factors. While some research has explored supplement use among adolescents in a school setting, no study has explored this across the private school system in South Africa. Additionally, given the important role that coaches/trainers play in adolescent development, it is critical to also understand the role that they play regarding adolescent supplement use, given that there has been limited research around this topic in South Africa. Therefore, there were two aims of this study; Firstly, this study explored the prevalence and perceptions (knowledge; attitudes; beliefs) of sports supplements among South African private high school adolescents. Secondly, this study explored the perceptions (knowledge; attitudes; application of knowledge) towards sports supplements among adolescent coaches/trainers in South African private high schools. Considering the dual aim of this study, this thesis was structured as a two-part research study. Both parts took the form of a cross-sectional design, using an online questionnaire to collect qualitative and quantitative data. In total, a cohort of n=50 adolescents and n=49 coaches/trainers participated. Adolescent participants reported a high prevalence of sports supplement use (62%) with their main reasons for using them being recovery and performance. Adolescents were primarily influenced/advised by friends and coaches/trainers to start using sports supplements. Coaches/trainers primarily relied on other coaches/trainers and internet advertising/sites as a main source of information. Less than half of the participants from both groups reported having any formal education or training related to sports nutrition or sports supplements. Both groups thought that these products are being misused by adolescents, which may account for why a portion of the adolescent participants reported experiencing adverse side-effects from using sports supplements, and a few coach/trainer participants reported witnessing this in their practice. This may be a result of the professionalisation of school sport which places pressure on athletes and their coaches/trainers to perform and may in turn be the reason why some adolescents reported that they would use, and some coaches/trainers reported they would recommend the use of sports supplements even if they were aware of risk/dangers involved. Thus, there is a need for education/training among South African high school adolescents and their coaches/trainers with respect to the use of sports supplements, so that they can make informed decisions from reliable sources of information or advice in order to use these products safely and effectively. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Butler, Nicholas John
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232443 , vital:49992
- Description: Sports supplements, also referred to as ergogenic aids, are used because of the assertion that they can enhance physical or athletic performance and/or physical appearance. Commonly used sports supplements include creatines, proteins, amino acids, stimulants, and in some cases pro-hormones. There is a relatively high and increasing prevalence of sports supplement use by the general population globally and in South Africa, particularly among adolescents and young adults due to various factors. While some research has explored supplement use among adolescents in a school setting, no study has explored this across the private school system in South Africa. Additionally, given the important role that coaches/trainers play in adolescent development, it is critical to also understand the role that they play regarding adolescent supplement use, given that there has been limited research around this topic in South Africa. Therefore, there were two aims of this study; Firstly, this study explored the prevalence and perceptions (knowledge; attitudes; beliefs) of sports supplements among South African private high school adolescents. Secondly, this study explored the perceptions (knowledge; attitudes; application of knowledge) towards sports supplements among adolescent coaches/trainers in South African private high schools. Considering the dual aim of this study, this thesis was structured as a two-part research study. Both parts took the form of a cross-sectional design, using an online questionnaire to collect qualitative and quantitative data. In total, a cohort of n=50 adolescents and n=49 coaches/trainers participated. Adolescent participants reported a high prevalence of sports supplement use (62%) with their main reasons for using them being recovery and performance. Adolescents were primarily influenced/advised by friends and coaches/trainers to start using sports supplements. Coaches/trainers primarily relied on other coaches/trainers and internet advertising/sites as a main source of information. Less than half of the participants from both groups reported having any formal education or training related to sports nutrition or sports supplements. Both groups thought that these products are being misused by adolescents, which may account for why a portion of the adolescent participants reported experiencing adverse side-effects from using sports supplements, and a few coach/trainer participants reported witnessing this in their practice. This may be a result of the professionalisation of school sport which places pressure on athletes and their coaches/trainers to perform and may in turn be the reason why some adolescents reported that they would use, and some coaches/trainers reported they would recommend the use of sports supplements even if they were aware of risk/dangers involved. Thus, there is a need for education/training among South African high school adolescents and their coaches/trainers with respect to the use of sports supplements, so that they can make informed decisions from reliable sources of information or advice in order to use these products safely and effectively. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-04
An analysis of inland fisheries resource use in the Eastern Cape, South Africa
- Authors: Matam, Ncumisa Yanga
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232215 , vital:49972
- Description: South Africa’s Draft Inland Fisheries Policy identifies inland fisheries as an opportunity for socio-economic benefits such as jobs, food security and economic development, based on small-scale fishing and recreational value chains. Using roving creel surveys, this study examined various fishing groups in publicly accessible dams in both an urban and a rural settlement in the Makana Municipal area, Eastern Cape, South Africa. While inland fisheries are particularly relevant for rural communities, there is very little information on the current use of these resources, irrespective of inland fisheries’ importance. This thesis presents a conceptual framework for a study that: (1) reviews available information of inland fisheries and development attempts in South Africa; (2) provides an assessment of the use of inland fisheries on publicly accessible dams in the Makana Municipal area and (3) evaluates case studies of current and past utilization of selected inland fisheries initiatives in the Eastern Cape. The results of this project provide insights into the current conditions and development potentials of inland fisheries in the Eastern Cape. There was a difference in species composition between the dams, but no difference in the CPUE between dams. For example, in Grey dam many species were present, but as the dam size is only one hectare, this would result in an estimated yield harvest of only 207 kg/ha/year. Anglers were encountered at all dams, although fish were only retrieved by anglers in the rural dams of Committees Drift. Dam usage in the rural area was mostly subsistence angling, and this was significantly greater than in the urban area. Subsistence fishers utilised the fish to sustain themselves and their families and for better livelihoods. Anglers from outside the area tended to utilise the dam for recreational angling. Dams found in the urban area were also mostly used by subsistence anglers, though there were a few uses for aesthetic purposes. The urban dams were also utilised recreationally (picnics, year-end functions, swimming), as opposed to the rural dams which were only used for angling. A total of 10 interviews were administered to key respondents in the form of a questionnaires to determine the importance of the fisheries to them. Catch documented from the questionnaires, interviews and logbooks constituted 1238 species and 978 020 kg. Of all the anglers encountered from the interviews, the gill net catch species varied by dam. The fate of fish caught by anglers was dependent on employment status, with most unemployed anglers selling their fish for income and most employed anglers consuming their catch. The findings show that dams were used mostly by small-scale fishers and recreational anglers. Ichthyological surveys revealed that popular fish harvested were moggel, common carp, largemouth bass and Mozambique tilapia. The results are discussed in the context of appropriate development of fisheries in small dams in the province, with recommendations to continue monitored surveys to better inform the inland fisheries policy. The findings from this thesis show that having small scale fisheries in place and providing good access to the dams is essential for rural populations, in turn, providing better livelihoods through hunger alleviation and generating household income. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Matam, Ncumisa Yanga
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232215 , vital:49972
- Description: South Africa’s Draft Inland Fisheries Policy identifies inland fisheries as an opportunity for socio-economic benefits such as jobs, food security and economic development, based on small-scale fishing and recreational value chains. Using roving creel surveys, this study examined various fishing groups in publicly accessible dams in both an urban and a rural settlement in the Makana Municipal area, Eastern Cape, South Africa. While inland fisheries are particularly relevant for rural communities, there is very little information on the current use of these resources, irrespective of inland fisheries’ importance. This thesis presents a conceptual framework for a study that: (1) reviews available information of inland fisheries and development attempts in South Africa; (2) provides an assessment of the use of inland fisheries on publicly accessible dams in the Makana Municipal area and (3) evaluates case studies of current and past utilization of selected inland fisheries initiatives in the Eastern Cape. The results of this project provide insights into the current conditions and development potentials of inland fisheries in the Eastern Cape. There was a difference in species composition between the dams, but no difference in the CPUE between dams. For example, in Grey dam many species were present, but as the dam size is only one hectare, this would result in an estimated yield harvest of only 207 kg/ha/year. Anglers were encountered at all dams, although fish were only retrieved by anglers in the rural dams of Committees Drift. Dam usage in the rural area was mostly subsistence angling, and this was significantly greater than in the urban area. Subsistence fishers utilised the fish to sustain themselves and their families and for better livelihoods. Anglers from outside the area tended to utilise the dam for recreational angling. Dams found in the urban area were also mostly used by subsistence anglers, though there were a few uses for aesthetic purposes. The urban dams were also utilised recreationally (picnics, year-end functions, swimming), as opposed to the rural dams which were only used for angling. A total of 10 interviews were administered to key respondents in the form of a questionnaires to determine the importance of the fisheries to them. Catch documented from the questionnaires, interviews and logbooks constituted 1238 species and 978 020 kg. Of all the anglers encountered from the interviews, the gill net catch species varied by dam. The fate of fish caught by anglers was dependent on employment status, with most unemployed anglers selling their fish for income and most employed anglers consuming their catch. The findings show that dams were used mostly by small-scale fishers and recreational anglers. Ichthyological surveys revealed that popular fish harvested were moggel, common carp, largemouth bass and Mozambique tilapia. The results are discussed in the context of appropriate development of fisheries in small dams in the province, with recommendations to continue monitored surveys to better inform the inland fisheries policy. The findings from this thesis show that having small scale fisheries in place and providing good access to the dams is essential for rural populations, in turn, providing better livelihoods through hunger alleviation and generating household income. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2022
- Full Text:
- Date Issued: 2022-04
An eco-physiological investigation of fisheries-induced evolution: comparing the resilience of larvae from exploited and unexploited commercial reef fish populations to projected ocean acidification
- Authors: Muller, Cuen
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232579 , vital:50004 , DOI 10.21504/10962/232579
- Description: It is now accepted that anthropogenic-induced climate change is resulting in unprecedented rates of change to marine environments. Marine organisms are being challenged by rapidly increasing temperatures, acidification, expansion of oxygen dead zones, and higher frequencies and magnitudes of extreme weather events. Exploited fish populations are also undergoing selective harvesting. Certain traits, such as large size, fast growth, and/or bold/active behaviours, are being actively targeted and removed from the population gene pool. This selective removal of individuals may compromise the capacity of fish populations to resist or recover from environmental disturbances and reduce their ability to adapt to a changing environment as many of these traits are heritable. As most marine fishes' embryonic and larval stages represent the period when individuals are most sensitive to environmental disturbances, they are a critical bottleneck to population persistence in the face of exploitation and climate change. This thesis aimed to quantify and compare the metabolic physiology, growth, and development of an exploited and endemic sparid, the roman seabream Chrysoblephus laticeps, during the early larval stages under 1) ocean acidification conditions expected by the year 2100 and 2) from populations experiencing dissimilar rates of exploitation. To quantify and compare the physiology of larvae, adult C. laticeps from an exploited population were captured and field-spawned. Fertilised eggs were placed into either control/present-day conditions (pH = 8.03, pCO2 ≈ 420 μatm) or high-pCO2/hypercapnic treatment conditions (pH = 7.63, pCO2 ≈ 1400 μatm). The metabolic physiology of individual larvae was determined using a novel rolling-regression technique on static respirometry data. Here, estimates of the minimum and maximum oxygen consumption rates (VO2) could be determined with high test-retest reliability. The very early developmental stages (yolk-sac stage) appeared resilient to high pCO2 conditions despite being exposed to treatment conditions throughout the embryonic stage. Preflexion larvae showed sensitivity to treatment conditions by exhibiting reduced metabolic and growth rates, consistent with metabolic depression, associated with environmental stress. However, by the onset of flexion, which coincides with gill development, acid-base regulation, and muscle differentiation, metabolic and growth rates of treatment larvae were significantly greater than that of controls. This suggests that acid-base regulation imposes a high cost to maintain internal pH homeostasis. Importantly, these elevated metabolic costs were likely mediated through increased feeding rates in experimental conditions where food was ad libitum. In natural conditions, where food availability may be varied, high pCO2 conditions could be associated with higher mortality rates. Based on evidence that protected/unexploited populations are more genetically diverse and are composed of individuals representing a greater range of metabolic phenotypes, offspring were collected from a protected population experiencing otherwise similar environmental conditions to the exploited population. Metabolic rates of control larvae were generally similar to those of the exploited population. However, minimum rates of VO2 were typically higher for larvae from the protected population at comparable life stages. Preflexion treatment larvae from the protected population did not appear to undergo a period of reduced metabolism or growth compared to their control counterparts. While metabolic rates at the onset of flexion were significantly higher for treatment larvae, this was not associated with growth differences. Growth over-compensation following periods of growth depression is often associated with deleterious effects, such as organ damage and body or developmental malformations. This suggests somewhat improved resilience to ocean acidification conditions. This thesis found evidence that larval C. laticeps are sensitive to ocean acidification conditions expected by 2100. When this stressor is combined with increasing thermal variability, changing current coastal regimes, and heterogeneous food availability, also expected to occur by 2100, ocean acidification may compromise the population persistence of this species. However, an energetics approach to stress-tolerance suggests that larvae from the protected population may inherently show greater resilience to climate change-related environmental stressors. Evidence that exploitation affects the resilience of fish larvae to climate change highlights the need for an evolutionary approach to fisheries management and the importance of spatial protection in maintaining larger and more resilient populations while providing the raw material essential for adaptation. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Muller, Cuen
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232579 , vital:50004 , DOI 10.21504/10962/232579
- Description: It is now accepted that anthropogenic-induced climate change is resulting in unprecedented rates of change to marine environments. Marine organisms are being challenged by rapidly increasing temperatures, acidification, expansion of oxygen dead zones, and higher frequencies and magnitudes of extreme weather events. Exploited fish populations are also undergoing selective harvesting. Certain traits, such as large size, fast growth, and/or bold/active behaviours, are being actively targeted and removed from the population gene pool. This selective removal of individuals may compromise the capacity of fish populations to resist or recover from environmental disturbances and reduce their ability to adapt to a changing environment as many of these traits are heritable. As most marine fishes' embryonic and larval stages represent the period when individuals are most sensitive to environmental disturbances, they are a critical bottleneck to population persistence in the face of exploitation and climate change. This thesis aimed to quantify and compare the metabolic physiology, growth, and development of an exploited and endemic sparid, the roman seabream Chrysoblephus laticeps, during the early larval stages under 1) ocean acidification conditions expected by the year 2100 and 2) from populations experiencing dissimilar rates of exploitation. To quantify and compare the physiology of larvae, adult C. laticeps from an exploited population were captured and field-spawned. Fertilised eggs were placed into either control/present-day conditions (pH = 8.03, pCO2 ≈ 420 μatm) or high-pCO2/hypercapnic treatment conditions (pH = 7.63, pCO2 ≈ 1400 μatm). The metabolic physiology of individual larvae was determined using a novel rolling-regression technique on static respirometry data. Here, estimates of the minimum and maximum oxygen consumption rates (VO2) could be determined with high test-retest reliability. The very early developmental stages (yolk-sac stage) appeared resilient to high pCO2 conditions despite being exposed to treatment conditions throughout the embryonic stage. Preflexion larvae showed sensitivity to treatment conditions by exhibiting reduced metabolic and growth rates, consistent with metabolic depression, associated with environmental stress. However, by the onset of flexion, which coincides with gill development, acid-base regulation, and muscle differentiation, metabolic and growth rates of treatment larvae were significantly greater than that of controls. This suggests that acid-base regulation imposes a high cost to maintain internal pH homeostasis. Importantly, these elevated metabolic costs were likely mediated through increased feeding rates in experimental conditions where food was ad libitum. In natural conditions, where food availability may be varied, high pCO2 conditions could be associated with higher mortality rates. Based on evidence that protected/unexploited populations are more genetically diverse and are composed of individuals representing a greater range of metabolic phenotypes, offspring were collected from a protected population experiencing otherwise similar environmental conditions to the exploited population. Metabolic rates of control larvae were generally similar to those of the exploited population. However, minimum rates of VO2 were typically higher for larvae from the protected population at comparable life stages. Preflexion treatment larvae from the protected population did not appear to undergo a period of reduced metabolism or growth compared to their control counterparts. While metabolic rates at the onset of flexion were significantly higher for treatment larvae, this was not associated with growth differences. Growth over-compensation following periods of growth depression is often associated with deleterious effects, such as organ damage and body or developmental malformations. This suggests somewhat improved resilience to ocean acidification conditions. This thesis found evidence that larval C. laticeps are sensitive to ocean acidification conditions expected by 2100. When this stressor is combined with increasing thermal variability, changing current coastal regimes, and heterogeneous food availability, also expected to occur by 2100, ocean acidification may compromise the population persistence of this species. However, an energetics approach to stress-tolerance suggests that larvae from the protected population may inherently show greater resilience to climate change-related environmental stressors. Evidence that exploitation affects the resilience of fish larvae to climate change highlights the need for an evolutionary approach to fisheries management and the importance of spatial protection in maintaining larger and more resilient populations while providing the raw material essential for adaptation. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04
An epistemic justice account of students’ experiences of feedback
- Authors: Vilakazi, Bella Phetheni
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232599 , vital:50006 , DOI 10.21504/10962/232599
- Description: I am a storyteller. I believe in the power of stories to share experiences and to elucidate thoughts and ideas and to help us to make sense of complex social practices. This thesis includes the stories of five young women who were learning to become teachers. As they shared their stories with me, I share them with you. This study includes their stories of receiving feedback. These stories are structured within the Narrative Inquiry dimensions of temporality, place and context. These dimensions suggest that stories are historical and move through time, stories are shaped by place and the context in which they unfold (Clandinin, 2013). Furthermore, these stories demonstrate how feedback can serve to give access to powerful knowledge and can serve to recognise who our students are and what they bring to the academy (Hordern, 2018). But feedback can also serve to misrecognise. Much has been written and reported about the barriers preventing students from acting on the feedback on their assignment tasks in higher education. In this study, I argue that feedback is a pedagogic practice that can support students to gain epistemic access. Feedback can only achieve this if it makes the expectations explicit for students to make sense of and make meaning for themselves and if it is offered in a dialogical format which recognises the students, their attempts, their identities, and their knowledge. The research question of this study, ‘How do experiences of forms of feedback affect female undergraduate student teachers’ chances of epistemic access?’, is not unusual. There have been many research projects that have been carried out that examine students’ experiences of feedback (for example, Evans, 2013; Basey, Maines, & Francis, 2014; Nicol et al.; 2014; Carless, 2019; Winstone et al., 2021). But I identified a gap where feedback has not, to my knowledge, been studied directly through the lenses of Epistemic Justice towards Parity of Participation. This study interpreted five undergraduate student teachers’ feedback experiences through these lenses. Narrative inquiry enabled me to design this study in ways that foregrounded experience. Data was collected through multiple conversations during which I organised the participants’ life stories of feedback within the dimensions of temporality, place and context, and sociality. Miranda Fricker’s (2007) theory of Epistemic Justice and Fraser’s norm of Parity of Participation (2000) framed this study. I engaged with Fricker and Fraser’s literature meaningfully as a reader and researcher. I established an understanding of how the lenses offered by Fraser and Fricker allowed me to make sense of the literature more generally, in social life and on the pedagogic practice of feedback. Fricker’s theory of Epistemic Justice considers the epistemically unjust, gendered, raced and classed, experiences of epistemic agents. Fricker (2007) draws on two central concepts to account for epistemic injustices: Testimonial Injustice and Hermeneutical Injustice. Fricker (2007; 2003) explains that testimonial injustice occurs within a testimonial exchange setting, when an epistemic agent as a speaker gives testimony of the epistemic agent’s experiences and knowledge but is not awarded the credibility the speaker deserves (Fricker, 2003). Epistemic agents who participate in a testimonial exchange need to overcome bias and prejudice in order to evaluate testimonies with the degree of fairness the testimony deserves (Fricker, 2013; 2016). Hermeneutical injustice occurs when an epistemic agent is unable to make sense and make meaning of their social experiences. Hermeneutical injustice strengthens when the epistemic agent is prevented from gaining access to resources that might help with sense making and meaning making of these social experiences (Dielman, 2012; Fricker, 2016). To ensure that meaning can be made between people and groups of people, there needs to be some shared understandings of the purpose and process of sense making and meaning-making – or a willingness to co-create such shared understandings. Fraser’s norm of Participatory Parity enabled a consideration of the larger world of political and economic systems that give rise to social injustice. In this study, the theories of Fricker and Fraser are used to illuminate experiences of feedback of the five undergraduate student teachers who are the participants in this study and how these translate to epistemic and social injustice. The norm of Participatory Parity is considered where feedback allowed or restricted participants from participating on an equal footing in the feedback process. Narrative inquiry, a research methodology that is used to study experiences, was used to inform research strategies of this study. Participants’ experiences, data collection and organising the narratives demonstrated the dimensions of temporality and space. The thesis includes biographical vignettes for each of the participants in the study, interspersed with data from across all five participants. The key findings of this study show that feedback generally operates at the surface levels of grammar correction. In light of the theoretical lenses of this study, I argue that the feedback experiences they shared generally did not recognise their attempts and the identities and knowledges they brought to the tasks. Because the focus was on superficial correction of the specific task, the feedback failed to create conditions for the (re)distribution of knowledge. At times the feedback exerted power on participants. Because the feedback was generally in the form of one directional correction (with little space for interaction with the feedback or dialogue with the assessor), this caused status subordination of participants in the epistemic spaces of teaching practice. Lastly, the lack of clarity of feedback was harmful to the potential for dialogical feedback. Such feedback caused participants to experience forms of epistemic injustice in the form of hermeneutical injustice where it failed to create conditions for the distribution of knowledge. Feedback also caused participants to experience testimonial injustice where it failed to create conditions for recognising participants’ processes of sense-making and meaning-making in the various assignment tasks. Participatory Parity could not occur because the processes of recognition and redistribution were constrained. Feedback then created fertile conditions of epistemic injustice to occur, and participants were likely to have failed to gain the much needed epistemic access. This study is not the story of bad, uncaring academics; the study acknowledges the context of large classes and heavy workloads in which feedback is or is not given. Rather, this is the story of five women trying to make their way through the university and out into the world as teachers. The study calls for better theorising of feedback and more support for both academics and students to develop feedback literacy so that feedback might serve as a dialogical pedagogic practice that enables epistemic justice. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Vilakazi, Bella Phetheni
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232599 , vital:50006 , DOI 10.21504/10962/232599
- Description: I am a storyteller. I believe in the power of stories to share experiences and to elucidate thoughts and ideas and to help us to make sense of complex social practices. This thesis includes the stories of five young women who were learning to become teachers. As they shared their stories with me, I share them with you. This study includes their stories of receiving feedback. These stories are structured within the Narrative Inquiry dimensions of temporality, place and context. These dimensions suggest that stories are historical and move through time, stories are shaped by place and the context in which they unfold (Clandinin, 2013). Furthermore, these stories demonstrate how feedback can serve to give access to powerful knowledge and can serve to recognise who our students are and what they bring to the academy (Hordern, 2018). But feedback can also serve to misrecognise. Much has been written and reported about the barriers preventing students from acting on the feedback on their assignment tasks in higher education. In this study, I argue that feedback is a pedagogic practice that can support students to gain epistemic access. Feedback can only achieve this if it makes the expectations explicit for students to make sense of and make meaning for themselves and if it is offered in a dialogical format which recognises the students, their attempts, their identities, and their knowledge. The research question of this study, ‘How do experiences of forms of feedback affect female undergraduate student teachers’ chances of epistemic access?’, is not unusual. There have been many research projects that have been carried out that examine students’ experiences of feedback (for example, Evans, 2013; Basey, Maines, & Francis, 2014; Nicol et al.; 2014; Carless, 2019; Winstone et al., 2021). But I identified a gap where feedback has not, to my knowledge, been studied directly through the lenses of Epistemic Justice towards Parity of Participation. This study interpreted five undergraduate student teachers’ feedback experiences through these lenses. Narrative inquiry enabled me to design this study in ways that foregrounded experience. Data was collected through multiple conversations during which I organised the participants’ life stories of feedback within the dimensions of temporality, place and context, and sociality. Miranda Fricker’s (2007) theory of Epistemic Justice and Fraser’s norm of Parity of Participation (2000) framed this study. I engaged with Fricker and Fraser’s literature meaningfully as a reader and researcher. I established an understanding of how the lenses offered by Fraser and Fricker allowed me to make sense of the literature more generally, in social life and on the pedagogic practice of feedback. Fricker’s theory of Epistemic Justice considers the epistemically unjust, gendered, raced and classed, experiences of epistemic agents. Fricker (2007) draws on two central concepts to account for epistemic injustices: Testimonial Injustice and Hermeneutical Injustice. Fricker (2007; 2003) explains that testimonial injustice occurs within a testimonial exchange setting, when an epistemic agent as a speaker gives testimony of the epistemic agent’s experiences and knowledge but is not awarded the credibility the speaker deserves (Fricker, 2003). Epistemic agents who participate in a testimonial exchange need to overcome bias and prejudice in order to evaluate testimonies with the degree of fairness the testimony deserves (Fricker, 2013; 2016). Hermeneutical injustice occurs when an epistemic agent is unable to make sense and make meaning of their social experiences. Hermeneutical injustice strengthens when the epistemic agent is prevented from gaining access to resources that might help with sense making and meaning making of these social experiences (Dielman, 2012; Fricker, 2016). To ensure that meaning can be made between people and groups of people, there needs to be some shared understandings of the purpose and process of sense making and meaning-making – or a willingness to co-create such shared understandings. Fraser’s norm of Participatory Parity enabled a consideration of the larger world of political and economic systems that give rise to social injustice. In this study, the theories of Fricker and Fraser are used to illuminate experiences of feedback of the five undergraduate student teachers who are the participants in this study and how these translate to epistemic and social injustice. The norm of Participatory Parity is considered where feedback allowed or restricted participants from participating on an equal footing in the feedback process. Narrative inquiry, a research methodology that is used to study experiences, was used to inform research strategies of this study. Participants’ experiences, data collection and organising the narratives demonstrated the dimensions of temporality and space. The thesis includes biographical vignettes for each of the participants in the study, interspersed with data from across all five participants. The key findings of this study show that feedback generally operates at the surface levels of grammar correction. In light of the theoretical lenses of this study, I argue that the feedback experiences they shared generally did not recognise their attempts and the identities and knowledges they brought to the tasks. Because the focus was on superficial correction of the specific task, the feedback failed to create conditions for the (re)distribution of knowledge. At times the feedback exerted power on participants. Because the feedback was generally in the form of one directional correction (with little space for interaction with the feedback or dialogue with the assessor), this caused status subordination of participants in the epistemic spaces of teaching practice. Lastly, the lack of clarity of feedback was harmful to the potential for dialogical feedback. Such feedback caused participants to experience forms of epistemic injustice in the form of hermeneutical injustice where it failed to create conditions for the distribution of knowledge. Feedback also caused participants to experience testimonial injustice where it failed to create conditions for recognising participants’ processes of sense-making and meaning-making in the various assignment tasks. Participatory Parity could not occur because the processes of recognition and redistribution were constrained. Feedback then created fertile conditions of epistemic injustice to occur, and participants were likely to have failed to gain the much needed epistemic access. This study is not the story of bad, uncaring academics; the study acknowledges the context of large classes and heavy workloads in which feedback is or is not given. Rather, this is the story of five women trying to make their way through the university and out into the world as teachers. The study calls for better theorising of feedback and more support for both academics and students to develop feedback literacy so that feedback might serve as a dialogical pedagogic practice that enables epistemic justice. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2022
- Full Text:
- Date Issued: 2022-04
An ethnographic exploration of black lesbians rape survivors’ access to support services in Cape Town South Africa
- Wilson, Kaythrine Esther Jacqueline
- Authors: Wilson, Kaythrine Esther Jacqueline
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/232646 , vital:50010
- Description: Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Wilson, Kaythrine Esther Jacqueline
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/232646 , vital:50010
- Description: Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Date Issued: 2022-04
An evaluation of osteoarthritis rehabilitative practices within a South African multidisciplinary rehabilitation setting
- Authors: Gilchrist, Robynne Claire
- Date: 2022-04
- Subjects: Osteoarthritis --Physical therapy --South Africa , Osteoarthritis –Patients--Treatment --South Africa , Medical rehabilitation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55278 , vital:51441
- Description: A multifaceted condition such as osteoarthritis is ideally suited in the realm of multidisciplinary management which focuses on holistic patient care. Literature has identified a bio-psycho-social approach to osteoarthritis management, however a lack of adherence to evidence-based guidelines is a concern previously found in the South African healthcare system. Aim: To evaluate and describe osteoarthritis rehabilitative practices among clinical and rehabilitative practitioners within a South African setting, thereby identifying current trends within a multidisciplinary rehabilitation landscape. Methods: A descriptive research methodology with a cross-sectional study design and a convenience sampling technique was used. The target population consisted of practitioners located within the South African public and private healthcare sectors. The professions included biokinetics, dietetics, general medicine, occupational therapy, personal training, pharmacy, physiotherapy, psychology and specialised medicine. A self-administered, online questionnaire surveyed practitioners’ management modalities, patient referral trends and views on multidisciplinary management. Descriptive data were presented as means (95 CIs) for categorical data and mean ± standard deviation for normally distributed data. Data were assessed for normality using the Shapiro-Wilk test. Significant results Conclusion: Practitioners recognised the value of a multidisciplinary approach, however the implementation of such an approach was fragmented. This disjointed management was facilitated by referral systems that do not fit with the theory of a bio-psycho-social approach. Poor communication among the different healthcare professions and practitioners may have exacerbated disjointed management. This study aimed to contribute to the mutual appreciation of the different professions in the multidisciplinary team and prevent trespassing on the roles of other professions by disseminating guidelines to facilitate the translation of evidence-based recommendations into clinical practice for the benefit of the osteoarthritis patient. , Thesis (MA) -- Faculty of Health Sciences, Human Movement Science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Gilchrist, Robynne Claire
- Date: 2022-04
- Subjects: Osteoarthritis --Physical therapy --South Africa , Osteoarthritis –Patients--Treatment --South Africa , Medical rehabilitation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55278 , vital:51441
- Description: A multifaceted condition such as osteoarthritis is ideally suited in the realm of multidisciplinary management which focuses on holistic patient care. Literature has identified a bio-psycho-social approach to osteoarthritis management, however a lack of adherence to evidence-based guidelines is a concern previously found in the South African healthcare system. Aim: To evaluate and describe osteoarthritis rehabilitative practices among clinical and rehabilitative practitioners within a South African setting, thereby identifying current trends within a multidisciplinary rehabilitation landscape. Methods: A descriptive research methodology with a cross-sectional study design and a convenience sampling technique was used. The target population consisted of practitioners located within the South African public and private healthcare sectors. The professions included biokinetics, dietetics, general medicine, occupational therapy, personal training, pharmacy, physiotherapy, psychology and specialised medicine. A self-administered, online questionnaire surveyed practitioners’ management modalities, patient referral trends and views on multidisciplinary management. Descriptive data were presented as means (95 CIs) for categorical data and mean ± standard deviation for normally distributed data. Data were assessed for normality using the Shapiro-Wilk test. Significant results Conclusion: Practitioners recognised the value of a multidisciplinary approach, however the implementation of such an approach was fragmented. This disjointed management was facilitated by referral systems that do not fit with the theory of a bio-psycho-social approach. Poor communication among the different healthcare professions and practitioners may have exacerbated disjointed management. This study aimed to contribute to the mutual appreciation of the different professions in the multidisciplinary team and prevent trespassing on the roles of other professions by disseminating guidelines to facilitate the translation of evidence-based recommendations into clinical practice for the benefit of the osteoarthritis patient. , Thesis (MA) -- Faculty of Health Sciences, Human Movement Science, 2022
- Full Text:
- Date Issued: 2022-04
An investigation of traveling ionospheric disturbances (TIDs) in the SANAE HF radar data
- Authors: Atilaw, Tsige Yared
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232377 , vital:49986 , DOI 10.21504/10962/232377
- Description: This thesis aims to study the characteristics of traveling ionospheric disturbances (TIDs) as identified in the radar data of the South African National Antarctic Expedition (SANAE) Super Dual Auroral Radar Network (SuperDARN) radar located in Antarctica. For this project, 22 TIDs were identified from visual inspection of range time-intensity (RTI) plots of backscattered power and Doppler velocity parameters of the SANAE radar between 2005âAS2015. These events were studied to determine their characteristics and driving mechanisms. Where good quality data were available, the SANAE HF radar data were supplemented by Halley radar data, which has large area of overlapping field of view (FOV) with the SANAE radar, and also by GPS TEC data. This provided a multi-instrument data analysis of some TID events. Different spectral analysis methods, namely the multitaper method (MTM), Fast Fourier transform (FFT) and the Lomb-Scargle periodogram were used to obtain spectral information of the observed waves. The advantage of using multiple windowing in MTM over the traditional windowing method was illustrated using one of the TID events. In addition, the analytic signal of the wave from the MTM method was used to estimate the instantaneous phase velocity and propagation azimuth of the wave, which was able to track the change in the characteristics of the medium-scale TID (MSTID) efficiently throughout the duration of the event. This is a clear advantage over other windowing techniques. The energy contribution by this MSTID through Joule heating was estimated over the region where spectral analysis of both SANAE and Halley data showed it to be present. The majority of the TIDs (65.4%) could be classified as MSTIDs with periods of 20–60 minutes, velocities of 50–333 ms1 and wavelengths of 129–833 km. The TID occurrence rate was high around the March equinox with 12 out of the 16 event days being during March–May. March had a particularly high number of occurrences of TIDs (46%). The majority of the TIDs observed during this month propagated northward or southeastward. In terms of prevailing geomagnetic conditions, 6 out of 16 event days were geomagnetically quiet, while 10 occurred during geomagnetic storms and substorms. During quiet conditions, TIDs could be linked to Es and polarised electric fields in 2 of these events. The other quiet time events could not be related to Es instability and polarised electric field either because their exact propagation direction could not be determined or data quality from the Es region scatter was too poor to perform spectral analysis. The storm-/substorm-related TIDs are possibly generated through Joule heating, the Lorentz force and energetic particle precipitation. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Atilaw, Tsige Yared
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232377 , vital:49986 , DOI 10.21504/10962/232377
- Description: This thesis aims to study the characteristics of traveling ionospheric disturbances (TIDs) as identified in the radar data of the South African National Antarctic Expedition (SANAE) Super Dual Auroral Radar Network (SuperDARN) radar located in Antarctica. For this project, 22 TIDs were identified from visual inspection of range time-intensity (RTI) plots of backscattered power and Doppler velocity parameters of the SANAE radar between 2005âAS2015. These events were studied to determine their characteristics and driving mechanisms. Where good quality data were available, the SANAE HF radar data were supplemented by Halley radar data, which has large area of overlapping field of view (FOV) with the SANAE radar, and also by GPS TEC data. This provided a multi-instrument data analysis of some TID events. Different spectral analysis methods, namely the multitaper method (MTM), Fast Fourier transform (FFT) and the Lomb-Scargle periodogram were used to obtain spectral information of the observed waves. The advantage of using multiple windowing in MTM over the traditional windowing method was illustrated using one of the TID events. In addition, the analytic signal of the wave from the MTM method was used to estimate the instantaneous phase velocity and propagation azimuth of the wave, which was able to track the change in the characteristics of the medium-scale TID (MSTID) efficiently throughout the duration of the event. This is a clear advantage over other windowing techniques. The energy contribution by this MSTID through Joule heating was estimated over the region where spectral analysis of both SANAE and Halley data showed it to be present. The majority of the TIDs (65.4%) could be classified as MSTIDs with periods of 20–60 minutes, velocities of 50–333 ms1 and wavelengths of 129–833 km. The TID occurrence rate was high around the March equinox with 12 out of the 16 event days being during March–May. March had a particularly high number of occurrences of TIDs (46%). The majority of the TIDs observed during this month propagated northward or southeastward. In terms of prevailing geomagnetic conditions, 6 out of 16 event days were geomagnetically quiet, while 10 occurred during geomagnetic storms and substorms. During quiet conditions, TIDs could be linked to Es and polarised electric fields in 2 of these events. The other quiet time events could not be related to Es instability and polarised electric field either because their exact propagation direction could not be determined or data quality from the Es region scatter was too poor to perform spectral analysis. The storm-/substorm-related TIDs are possibly generated through Joule heating, the Lorentz force and energetic particle precipitation. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2022
- Full Text:
- Date Issued: 2022-04
Be more than a bystander, break the silence on violence: a discursive analysis of student responses to anti-rape poster campaigns
- Authors: Skae, Shannon Lalla Rookh
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232866 , vital:50033
- Description: University students are a population vulnerable to sex and gender-based violence (SGBV). The use of alcohol is prominent in university life and is argued to contribute significantly to SGBV in South Africa and worldwide. Interventions to reduce SGBV at South African universities are thus a relevant social concern. One increasingly popular approach to addressing SGBV on university campuses is the bystander intervention. The bystander intervention goes to the cause of SGBV by targeting peer acceptance as the primary foundation supporting rape; arguing that witnesses to SGBV can be empowered to interrupt potential SGBV situations. The aim of this thesis was to investigate student responses to anti-rape intervention campaigns of various kinds. Different theories were examined, and this research then proceeded from a social constructionist theoretical perspective, which was relevant as it is about what individuals say, the societies formed, the rules made, the language used to pass on knowledge and the interactions experienced with others and how they all form the reality people inhabit. The study focused on the individual constructions and talk about the posters and the discursive positions he or she took up in relation to them, which is what social constructionism is interested in, as it is concerned with the language and talk people use and how these are molded by society. Forty five student volunteer participants were shown two examples of anti-rape poster campaigns (one using the bystander approach and the other not), and were asked to respond to a structured open-ended questionnaire. Responses to the questionnaire were subjected to Foucauldian Discourse Analysis (FDA). The analysis revealed the ways in which the constructions of sexual violence, perpetrators and victims in the poster campaigns shaped and limited participant responses and talk about SGBV in different ways, according to which of the two posters were being responded to. Key findings of this study showed that the bystander intervention poster produced more positive change in response to dominant discursive constructions in relation to the SGBV poster than did the non-bystander intervention poster. This means the establishment of the potential for success of the bystander intervention in helping to prevent SGBV in a South African context. , Thesis (MA) -- Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Skae, Shannon Lalla Rookh
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232866 , vital:50033
- Description: University students are a population vulnerable to sex and gender-based violence (SGBV). The use of alcohol is prominent in university life and is argued to contribute significantly to SGBV in South Africa and worldwide. Interventions to reduce SGBV at South African universities are thus a relevant social concern. One increasingly popular approach to addressing SGBV on university campuses is the bystander intervention. The bystander intervention goes to the cause of SGBV by targeting peer acceptance as the primary foundation supporting rape; arguing that witnesses to SGBV can be empowered to interrupt potential SGBV situations. The aim of this thesis was to investigate student responses to anti-rape intervention campaigns of various kinds. Different theories were examined, and this research then proceeded from a social constructionist theoretical perspective, which was relevant as it is about what individuals say, the societies formed, the rules made, the language used to pass on knowledge and the interactions experienced with others and how they all form the reality people inhabit. The study focused on the individual constructions and talk about the posters and the discursive positions he or she took up in relation to them, which is what social constructionism is interested in, as it is concerned with the language and talk people use and how these are molded by society. Forty five student volunteer participants were shown two examples of anti-rape poster campaigns (one using the bystander approach and the other not), and were asked to respond to a structured open-ended questionnaire. Responses to the questionnaire were subjected to Foucauldian Discourse Analysis (FDA). The analysis revealed the ways in which the constructions of sexual violence, perpetrators and victims in the poster campaigns shaped and limited participant responses and talk about SGBV in different ways, according to which of the two posters were being responded to. Key findings of this study showed that the bystander intervention poster produced more positive change in response to dominant discursive constructions in relation to the SGBV poster than did the non-bystander intervention poster. This means the establishment of the potential for success of the bystander intervention in helping to prevent SGBV in a South African context. , Thesis (MA) -- Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-04
Bioethical analysis of COVID19, WASH/waste and related disaster management implications
- Authors: Iheanetu, Chidinma
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232250 , vital:49975
- Description: Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Iheanetu, Chidinma
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232250 , vital:49975
- Description: Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2022
- Full Text:
- Date Issued: 2022-04
Characterising the sleep-wake behaviour of adolescents in a sample of South African high school students in Makhanda, Eastern Cape
- Authors: Mandondo, Nathasha Luleka
- Date: 2022-04
- Subjects: Sleep-wake cycle South Africa Makhanda , Sleep deprivation South Africa Makhanda , Academic achievement South Africa Makhanda , Mood (Psychology) South Africa Makhanda , High school students Conduct of life , Teenagers Health and hygiene South Africa Makhanda , Teenagers Sleep South Africa Makhanda , Depression in adolescence South Africa Makhanda
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/245714 , vital:51398
- Description: Sleep plays a significant role during adolescence. Overall, sleep is essential for growth and development, cognitive function, memory consolidation, concentration, alertness, mental and physical health, as well as the overall quality of life. During adolescence though, sleep-wake behaviour has been shown to undergo drastic changes, progressing from the early ages of 11-13 years through to late adolescence while attending school. During this period, adolescents experience later bedtimes, earlier waketimes, and less than recommended sleep durations, especially on weekdays during the school term. On weekends, however, adolescents tend to further delay their bed and wake times, resulting in discrepancies between week-and-weekend sleep-wake behavior. These changes are driven by a variety of systemic factors, that include biological, psychosocial, school, and behavioural changes that adolescents experience. The interaction of systematic factors has been described as the “Perfect Storm of insufficient and inappropriately-timed sleep” (Carskadon, 2011a; Crowley et al., 2018). While previous research on adolescent sleep has been focused mainly in countries of the Global North, there has been comparatively less research in the Global South, particularly in countries like South Africa, and in out of large city centres like Johannesburg and Cape Town. It is also not known what the impact of certain demographic factors, such as learner sex, boarding/day schooling, and public/private schooling is on sleep-wake habits. Therefore, the purpose of this study was to explore the sleep-wake behaviour of a sample of late adolescents from public and private schools in Makhanda in the Eastern Cape of South Africa and to make comparisons between different groups within. Method: This study is comprised of two phases. Phase one adopted a cross-sectional design to characterise Grade 12 learners' (final year students) sleep-wake behaviour across various public and private schools. This was achieved through the administration of an amended version of the School Sleep Habits Survey (SSHS). The SSHS included questions that capture demographic information, academic performance, sleep duration at different times of the week and also incorporated scales to assess daytime sleepiness, sleep-wake behavior problems, depressive mood, and chronotype. Phase two adopted an observational descriptive design. The sleep-wake behaviour of a sample of Grade 11 learners was tracked for 9 days using the Core Consensus Sleep Diary and Actigraphy. Data were not normally distributed and were thus analysed using non-parametric statistics and all data were displayed as the median and interquartile range (no 1-3). Results: Analysed surveys totalled 231. All participants were Grade 12s (final year of high school), aged between 17-19, from three private schools (n=152) and two public schools (n=79). The sample consisted of students identifying as females (n=94) and males (n=137). Participants self-identified as either Black/African (n=73), White (n=125), Colored (n=32) and as Indian (n=1). Over half of the sample lived in boarding houses/hostels (n=130) and slightly less than half (n=95) were day scholars. For Phase One, the median obtained for self-reported sleep duration on weekdays was 07hrs (06hrs-07hrs:18min) and 08hrs (07hrs-09hrs) on the weekend (p<0.01; z=10). The median for self-reported bedtime on weeknights was 11:00 (10:30-11:30) p.m., while on the weekends, it was an hour later i.e., 12:00 a.m. (11:00 p.m. -12:37 a.m.; p<0.01; z=9.4). Self-reported waketime on weekdays was 06:20 (06:00-06:30) a.m. and it was one-hour forty minutes later on weekends i.e., 08:00 (07:00-09:00) a.m. (p<0.01; z=13). With regards to sex differences on school mornings, females reported waking up 14 minutes later than their male counterparts (p<0.01; z=-3.1). On school mornings, day scholars reported significantly earlier waketimes than boarders (p<0.01; z=8.1). The opposite was found on weekends with day scholars reporting significantly later waketimes than boarders (p<0.01; z=-4.1) while day scholars reported going to bed significantly later than boarders during weekends (p<0.01; z=-2.7). There were noteworthy differences between types of schools with public school learners reporting earlier bed (p<0.01; z=3.9) and wake times (p<0.01; z=10) than private school learners on weekdays. On the weekend, however, public school learners reporting later bed (p=0.01; z=-2.7) and wake times (p<0.01; z=-4.4) than private school learners. Overall, the Grade 12 learners scored 12 (11-15) on the depressed mood scale indicating a trend towards high self-reported depressive symptoms, and 26 (23-30) on the ME scale, which demonstrated that this sample population reflects a preference for neither evenings nor mornings. The majority (75 %; n=174) of the Grade12 learners perceived themselves as getting too little sleep, 59% (n=134) reported waking up at least once during the night and 92% (n=213) reported experiencing varying degrees of daytime sleepiness. There was a relationship between caffeine consumption and usage of electronic devices (EDs) before bedtime and some sleep parameters. Specifically, the frequency of consumption of coffee/tea and soda had a medium and positive correlation with sleep onset latency as well as to the scale of sleep-wake problems. Academic performance was also positively and significantly correlated with self-reported mean weekday waketime and negatively correlated with mean weekend sleep duration as well as Weekend Waketime Delay (WWD). For Phase Two, the median self-reported sleep duration for 14 female boarders recorded in sleep diaries i.e.,07:32 (07:22-07:55) and the total sleep time (TST) recorded by the actigraphy i.e., 07:06 (06:54-07:35) and was less than the recommended sleep duration of 8-10 hours for adolescents and not significantly different (p=0.18; z=1.3). However, median sleep duration on the weekend was significantly longer on both actigraphs (08:16; 07:22-08:40) and sleep diaries (08:24; 07:59-08:51) and not significantly different (p=0.3; z=1.1). Overall, bedtimes, waketimes, and sleep onset latency, for both weekdays and weekends, did not differ significantly between the sleep diary responses and actigraph recordings. Discussion: Adolescents in this cohort, like many around the world report weekday sleep durations that are shorter than the recommended 8-10 hours. This may probably partly be explained by later bedtimes influenced by academic obligations, bedtime autonomy, and screen time as well as early waketimes influenced by school start times as indicated in the reasons given for bedtimes. Insufficient sleep during school nights, in this cohort, likely resulted in an accumulated sleep debt which may explain the extended sleep duration and later waketimes on weekends. Weekday waketimes were probably determined by commuting and school-related demands, specifically, school start times as indicated in the reasons given for waketimes. Thus, the results of this study do, in part, align with the factors outlined in the Perfect Storm model of poorly timed and insufficient sleep in adolescents proposed by Carskadon (2011a). Personal characteristics or contextual factors, such as being a boarder or a day scholar, attending a public or private school as well sex differences, accompanied by lifestyle factors such as the consumption of caffeine and usage of electrical devices may have interacted and influenced bed and wake times, resulting in what has been termed “a Perfect Storm of insufficient and inappropriately-timed sleep” in this cohort. Conclusion: The current study provided new insight into the sleep-wake behaviour of late adolescents in Makhanda, Eastern Cape of South Africa. More research is encouraged in the South African context. This knowledge can be used to implement contextually appropriate sleep hygiene education programs in the school curriculum and on an individual level. Furthermore, the results point to the fact that early school start times, in concert with other lifestyle and personal factors may be contributing to insufficient sleep in this group. These results, therefore, highlight the need for schools in this context to consider interventions such as delaying school start times to possibly improve sleep in this context. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Mandondo, Nathasha Luleka
- Date: 2022-04
- Subjects: Sleep-wake cycle South Africa Makhanda , Sleep deprivation South Africa Makhanda , Academic achievement South Africa Makhanda , Mood (Psychology) South Africa Makhanda , High school students Conduct of life , Teenagers Health and hygiene South Africa Makhanda , Teenagers Sleep South Africa Makhanda , Depression in adolescence South Africa Makhanda
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/245714 , vital:51398
- Description: Sleep plays a significant role during adolescence. Overall, sleep is essential for growth and development, cognitive function, memory consolidation, concentration, alertness, mental and physical health, as well as the overall quality of life. During adolescence though, sleep-wake behaviour has been shown to undergo drastic changes, progressing from the early ages of 11-13 years through to late adolescence while attending school. During this period, adolescents experience later bedtimes, earlier waketimes, and less than recommended sleep durations, especially on weekdays during the school term. On weekends, however, adolescents tend to further delay their bed and wake times, resulting in discrepancies between week-and-weekend sleep-wake behavior. These changes are driven by a variety of systemic factors, that include biological, psychosocial, school, and behavioural changes that adolescents experience. The interaction of systematic factors has been described as the “Perfect Storm of insufficient and inappropriately-timed sleep” (Carskadon, 2011a; Crowley et al., 2018). While previous research on adolescent sleep has been focused mainly in countries of the Global North, there has been comparatively less research in the Global South, particularly in countries like South Africa, and in out of large city centres like Johannesburg and Cape Town. It is also not known what the impact of certain demographic factors, such as learner sex, boarding/day schooling, and public/private schooling is on sleep-wake habits. Therefore, the purpose of this study was to explore the sleep-wake behaviour of a sample of late adolescents from public and private schools in Makhanda in the Eastern Cape of South Africa and to make comparisons between different groups within. Method: This study is comprised of two phases. Phase one adopted a cross-sectional design to characterise Grade 12 learners' (final year students) sleep-wake behaviour across various public and private schools. This was achieved through the administration of an amended version of the School Sleep Habits Survey (SSHS). The SSHS included questions that capture demographic information, academic performance, sleep duration at different times of the week and also incorporated scales to assess daytime sleepiness, sleep-wake behavior problems, depressive mood, and chronotype. Phase two adopted an observational descriptive design. The sleep-wake behaviour of a sample of Grade 11 learners was tracked for 9 days using the Core Consensus Sleep Diary and Actigraphy. Data were not normally distributed and were thus analysed using non-parametric statistics and all data were displayed as the median and interquartile range (no 1-3). Results: Analysed surveys totalled 231. All participants were Grade 12s (final year of high school), aged between 17-19, from three private schools (n=152) and two public schools (n=79). The sample consisted of students identifying as females (n=94) and males (n=137). Participants self-identified as either Black/African (n=73), White (n=125), Colored (n=32) and as Indian (n=1). Over half of the sample lived in boarding houses/hostels (n=130) and slightly less than half (n=95) were day scholars. For Phase One, the median obtained for self-reported sleep duration on weekdays was 07hrs (06hrs-07hrs:18min) and 08hrs (07hrs-09hrs) on the weekend (p<0.01; z=10). The median for self-reported bedtime on weeknights was 11:00 (10:30-11:30) p.m., while on the weekends, it was an hour later i.e., 12:00 a.m. (11:00 p.m. -12:37 a.m.; p<0.01; z=9.4). Self-reported waketime on weekdays was 06:20 (06:00-06:30) a.m. and it was one-hour forty minutes later on weekends i.e., 08:00 (07:00-09:00) a.m. (p<0.01; z=13). With regards to sex differences on school mornings, females reported waking up 14 minutes later than their male counterparts (p<0.01; z=-3.1). On school mornings, day scholars reported significantly earlier waketimes than boarders (p<0.01; z=8.1). The opposite was found on weekends with day scholars reporting significantly later waketimes than boarders (p<0.01; z=-4.1) while day scholars reported going to bed significantly later than boarders during weekends (p<0.01; z=-2.7). There were noteworthy differences between types of schools with public school learners reporting earlier bed (p<0.01; z=3.9) and wake times (p<0.01; z=10) than private school learners on weekdays. On the weekend, however, public school learners reporting later bed (p=0.01; z=-2.7) and wake times (p<0.01; z=-4.4) than private school learners. Overall, the Grade 12 learners scored 12 (11-15) on the depressed mood scale indicating a trend towards high self-reported depressive symptoms, and 26 (23-30) on the ME scale, which demonstrated that this sample population reflects a preference for neither evenings nor mornings. The majority (75 %; n=174) of the Grade12 learners perceived themselves as getting too little sleep, 59% (n=134) reported waking up at least once during the night and 92% (n=213) reported experiencing varying degrees of daytime sleepiness. There was a relationship between caffeine consumption and usage of electronic devices (EDs) before bedtime and some sleep parameters. Specifically, the frequency of consumption of coffee/tea and soda had a medium and positive correlation with sleep onset latency as well as to the scale of sleep-wake problems. Academic performance was also positively and significantly correlated with self-reported mean weekday waketime and negatively correlated with mean weekend sleep duration as well as Weekend Waketime Delay (WWD). For Phase Two, the median self-reported sleep duration for 14 female boarders recorded in sleep diaries i.e.,07:32 (07:22-07:55) and the total sleep time (TST) recorded by the actigraphy i.e., 07:06 (06:54-07:35) and was less than the recommended sleep duration of 8-10 hours for adolescents and not significantly different (p=0.18; z=1.3). However, median sleep duration on the weekend was significantly longer on both actigraphs (08:16; 07:22-08:40) and sleep diaries (08:24; 07:59-08:51) and not significantly different (p=0.3; z=1.1). Overall, bedtimes, waketimes, and sleep onset latency, for both weekdays and weekends, did not differ significantly between the sleep diary responses and actigraph recordings. Discussion: Adolescents in this cohort, like many around the world report weekday sleep durations that are shorter than the recommended 8-10 hours. This may probably partly be explained by later bedtimes influenced by academic obligations, bedtime autonomy, and screen time as well as early waketimes influenced by school start times as indicated in the reasons given for bedtimes. Insufficient sleep during school nights, in this cohort, likely resulted in an accumulated sleep debt which may explain the extended sleep duration and later waketimes on weekends. Weekday waketimes were probably determined by commuting and school-related demands, specifically, school start times as indicated in the reasons given for waketimes. Thus, the results of this study do, in part, align with the factors outlined in the Perfect Storm model of poorly timed and insufficient sleep in adolescents proposed by Carskadon (2011a). Personal characteristics or contextual factors, such as being a boarder or a day scholar, attending a public or private school as well sex differences, accompanied by lifestyle factors such as the consumption of caffeine and usage of electrical devices may have interacted and influenced bed and wake times, resulting in what has been termed “a Perfect Storm of insufficient and inappropriately-timed sleep” in this cohort. Conclusion: The current study provided new insight into the sleep-wake behaviour of late adolescents in Makhanda, Eastern Cape of South Africa. More research is encouraged in the South African context. This knowledge can be used to implement contextually appropriate sleep hygiene education programs in the school curriculum and on an individual level. Furthermore, the results point to the fact that early school start times, in concert with other lifestyle and personal factors may be contributing to insufficient sleep in this group. These results, therefore, highlight the need for schools in this context to consider interventions such as delaying school start times to possibly improve sleep in this context. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-04
Composition portfolio
- Authors: Lemmer, Elizabeth Kate
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232624 , vital:50008
- Description: In this portfolio I reflect on issues Covid-19 has brought to our communities and the possibilities of creating a brighter future. My music reflects the struggle that most people have faced in the last two years, the emotions and the conspiracies surrounding the experience, and the effect of solitude. In a time such as this it is almost inevitable that the music being composed is connected to the struggle in society at large. For ma composition is a journal of the heart. The pandemic has created a situation where most are out of touch with each other, have lost all previous routine and structure, where relationships are broken due to lack of personal contact, and almost everyone has unwillingly (or unwittingly) been thrust into self-reflection. Every day sees a new struggle to squeeze in all those pre-pandemic ideals so that some normalcy can be obtained, but this is not a time to be looking back. It’s a time to understand what we are going through, build new joy and excitement for this different life and learn to live the best we can with the opportunities we are given. There has not been a more important time to foster some form of connection with friends and family, and to be as strong and supportive as possible. The portfolio begins with a solo violin piece, Unwelcome Solitude, which exemplifies the loneliness and sadness during the various lockdowns over the last two years, with hints of the past and the difficulties in trying to resurrect pre-Covid-19 times. There are some unusual expressive markings to add to the descriptive effect within the piece. This is followed by The Pandemic, two serialism works: Panic and Pain scored for a string quartet. Both of these pieces apply a flexible use of serialism to emphasize out the emotional aspects of the music, and quite simply; the panic and the pain caused by Covid-19 and the country’s response to the pandemic as a whole. Finally there is a three movement chamber piece titled A Storm Series which quite literally represents the series of events that occur from the upcoming to the closure of a typical Highveld storm. Further than this, these pieces represent the series of events that occurred in South Africa from the first rumour of the Covid-19 virus starting to circle around the world, through the various lockdowns and progression of events in our country and abroad. The final movement of this series, Re-awakening, ends on a positive note representing the rainbow at the end of the storm, and the positive outlook for South Africa to keep persevering through the pandemic. , Thesis (MMus) -- Faculty of Humanities, Music and Musicology, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Lemmer, Elizabeth Kate
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232624 , vital:50008
- Description: In this portfolio I reflect on issues Covid-19 has brought to our communities and the possibilities of creating a brighter future. My music reflects the struggle that most people have faced in the last two years, the emotions and the conspiracies surrounding the experience, and the effect of solitude. In a time such as this it is almost inevitable that the music being composed is connected to the struggle in society at large. For ma composition is a journal of the heart. The pandemic has created a situation where most are out of touch with each other, have lost all previous routine and structure, where relationships are broken due to lack of personal contact, and almost everyone has unwillingly (or unwittingly) been thrust into self-reflection. Every day sees a new struggle to squeeze in all those pre-pandemic ideals so that some normalcy can be obtained, but this is not a time to be looking back. It’s a time to understand what we are going through, build new joy and excitement for this different life and learn to live the best we can with the opportunities we are given. There has not been a more important time to foster some form of connection with friends and family, and to be as strong and supportive as possible. The portfolio begins with a solo violin piece, Unwelcome Solitude, which exemplifies the loneliness and sadness during the various lockdowns over the last two years, with hints of the past and the difficulties in trying to resurrect pre-Covid-19 times. There are some unusual expressive markings to add to the descriptive effect within the piece. This is followed by The Pandemic, two serialism works: Panic and Pain scored for a string quartet. Both of these pieces apply a flexible use of serialism to emphasize out the emotional aspects of the music, and quite simply; the panic and the pain caused by Covid-19 and the country’s response to the pandemic as a whole. Finally there is a three movement chamber piece titled A Storm Series which quite literally represents the series of events that occur from the upcoming to the closure of a typical Highveld storm. Further than this, these pieces represent the series of events that occurred in South Africa from the first rumour of the Covid-19 virus starting to circle around the world, through the various lockdowns and progression of events in our country and abroad. The final movement of this series, Re-awakening, ends on a positive note representing the rainbow at the end of the storm, and the positive outlook for South Africa to keep persevering through the pandemic. , Thesis (MMus) -- Faculty of Humanities, Music and Musicology, 2022
- Full Text:
- Date Issued: 2022-04
Demersal fish distribution in the shallow marine nearshore and estuarine seascape of Algoa Bay: Nursery areas and the effect of environmental drivers
- Authors: Nodo, Phakama
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232399 , vital:49988 , DOI 10.21504/10962/232399
- Description: Estuaries and shallow marine nearshore areas are highly productive and valuable ecosystems, which provide numerous habitats for fish and support fundamental ecological links with other environments. Assessing fish distribution across estuarine and marine nearshore habitats is important to identify ecologically important habitats and develop effective management strategies for coastal fishes, many of which are important fishery species. Despite this, only a few studies have focussed on fish community patterns across an estuary and marine nearshore gradient concurrently, particularly including early life history stages, to determine the nursery value of both environments, and to examine whether these two coastal environments have distinct fish assemblages in relation to physical factors. The main aim of this study was to assess the environmental drivers of demersal fish communities in soft-bottom benthic habitats in two permanently open estuaries and adjacent marine nearshore areas (5 – 10 m) of Algoa Bay, South Africa, as well as to assess the relative roles of these two habitats as settlement and nursery areas for demersal fish species. A 1.5 m, conical shoeless beam trawl net was used to sample the demersal fish community concurrently in each habitat between July 2017 and September 2019. Sampling was conducted in July 2017, February, March, May, July, August, October and November 2019 and February, April and September 2019. DNA barcoding was used to verify identification of the early life history stages of fish caught in the estuarine and marine nearshore areas of Algoa Bay. In addition, since the two estuaries (Swartkops and Sundays) are heavily polluted, the effect of low dissolved oxygen and hypoxia and associated shifts in spatial distribution of demersal species was investigated. The two sampled estuaries had a higher abundance of demersal fishes, with a total of 6437 fishes (28 species) caught (3752 and 2685 individuals with 24 and 20 species recorded in the Sundays and Swartkops estuaries, respectively). Species richness was higher in the marine nearshore of Algoa Bay, with 29 species (797 individuals) caught. Of the 7234 individuals caught, the identification of 100 specimens, in either a larval or early juvenile phase, were uncertain and therefore DNA barcoding was used to verify their identification. Of these 100 individuals, 86 were positively identified to species level using COI sequences. Fourteen failed to amplify by PCR and could only be identified morphologically. The marine nearshore sites were dominated by species which spawn in the marine environment and are not dependent on estuaries (marine species and marine estuary-opportunists), whilst the estuaries were dominated by estuarine spawners or marine spawners dependent on estuaries to some degree. Two discrete demersal fish assemblages were identified representing the marine nearshore and the estuary, with no significant differences observed between the two estuaries (Sundays and Swartkops). The differences observed between the marine nearshore and estuary were mostly driven by salinity, turbidity, silt and organic content of the sediment. These distinct fish assemblages might be considered as indicators for the respective environments they inhabit. Both habitats were dominated by early life history stages (larvae to juveniles), indicating the nursery function of both habitats. Early life stages collectively comprised 97% of the catch in the marine nearshore and 68% in the estuary. Young-of-the-year (YOY) juveniles (< 1-year-old juveniles) and transformation stages (when changes in body shape and pigment pattern occur) dominated the total catch in the marine nearshore, while YOY juveniles dominated the estuarine fish assemblages. Ariidae Galeichthys feliceps, Haemulidae Pomadasys olivaceus, Sciaenidae Argyrosomus inodorus and Cynoglossidae Cynoglossus zanzibarensis, comprised the largest proportion of YOY juveniles in the marine nearshore. The transformation stage in the marine nearshore was numerically dominated by P. olivaceus and G. feliceps. In the estuarine environment, YOY juveniles were mostly dominated by Sparidae Rhabdosargus holubi, Soleidae Heteromycteris capensis and Gobiidae Caffrogobius gilchristi. The greatest abundance of early life stage fishes was observed in the lower reaches of the Sundays Estuary and the upper reaches of the Swartkops Estuary, as well as nearshore sites located in close proximity to the estuary mouths, particularly during spring and summer. Despite the fact that these coastal ecosystems are important nursery areas, they are threatened by a number of factors, including habitat loss and modification due to urban development, intensification of agriculture and subsequent eutrophication, climate change, and overfishing, all of which reduce ecosystem functioning and reduce the ecological and economic value of these habitats around the world. Hypoxia is one of the major threats to the functioning of coastal ecosystems, particularly estuaries. The Sundays and Swartkops estuaries both experience persistent eutrophic conditions, with frequent phytoplankton blooms (> 20 μg Chl-a l-1) that result in instances of bottom water oxygen depletion (< 4 mg/l). During the present study in the Sundays Estuary, low oxygen waters were recorded in the middle reaches (Site S5) mostly during summer (four months of low DO conditions). In the Swartkops Estuary, low dissolved oxygen was recorded in the upper reaches during spring. The lowest dissolved oxygen concentration recorded was 0.5 mg/l and 2.4 mg/l in the bottom waters of the Sundays and Swartkops estuaries, respectively. Selected dominant species were only absent from areas where dissolved oxygen was < 1 mg/l and present in the adjacent sites (for example Site S4, and S3) where DO was higher mostly during January 2019. As such, the low dissolved oxygen concentrations recorded in the Swartkops Estuary did not have a noticeable impact on fish distribution, although the total abundance of species did show a slight decline when dissolved oxygen was < 3 mg/l. This study demonstrates the importance of concurrently examining estuarine and nearshore marine habitats in order to identify ecologically important habitats, which has important implications for the development of effective management strategies for coastal fish populations, particularly in the light of anthropogenic change. In addition, in order to identify nursery hotspots it is crucial to correctly identify all the species occupying these areas. As such, this study confirms the importance of also using DNA barcoding for fish identification, particularly for the early life history stages of cryptic species (e.g. Argyrosomus inodorus and Argyrosomus japonicus). , Thesis (PhD) -- Faculty of Science, Ichthyology & Fisheries Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Nodo, Phakama
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232399 , vital:49988 , DOI 10.21504/10962/232399
- Description: Estuaries and shallow marine nearshore areas are highly productive and valuable ecosystems, which provide numerous habitats for fish and support fundamental ecological links with other environments. Assessing fish distribution across estuarine and marine nearshore habitats is important to identify ecologically important habitats and develop effective management strategies for coastal fishes, many of which are important fishery species. Despite this, only a few studies have focussed on fish community patterns across an estuary and marine nearshore gradient concurrently, particularly including early life history stages, to determine the nursery value of both environments, and to examine whether these two coastal environments have distinct fish assemblages in relation to physical factors. The main aim of this study was to assess the environmental drivers of demersal fish communities in soft-bottom benthic habitats in two permanently open estuaries and adjacent marine nearshore areas (5 – 10 m) of Algoa Bay, South Africa, as well as to assess the relative roles of these two habitats as settlement and nursery areas for demersal fish species. A 1.5 m, conical shoeless beam trawl net was used to sample the demersal fish community concurrently in each habitat between July 2017 and September 2019. Sampling was conducted in July 2017, February, March, May, July, August, October and November 2019 and February, April and September 2019. DNA barcoding was used to verify identification of the early life history stages of fish caught in the estuarine and marine nearshore areas of Algoa Bay. In addition, since the two estuaries (Swartkops and Sundays) are heavily polluted, the effect of low dissolved oxygen and hypoxia and associated shifts in spatial distribution of demersal species was investigated. The two sampled estuaries had a higher abundance of demersal fishes, with a total of 6437 fishes (28 species) caught (3752 and 2685 individuals with 24 and 20 species recorded in the Sundays and Swartkops estuaries, respectively). Species richness was higher in the marine nearshore of Algoa Bay, with 29 species (797 individuals) caught. Of the 7234 individuals caught, the identification of 100 specimens, in either a larval or early juvenile phase, were uncertain and therefore DNA barcoding was used to verify their identification. Of these 100 individuals, 86 were positively identified to species level using COI sequences. Fourteen failed to amplify by PCR and could only be identified morphologically. The marine nearshore sites were dominated by species which spawn in the marine environment and are not dependent on estuaries (marine species and marine estuary-opportunists), whilst the estuaries were dominated by estuarine spawners or marine spawners dependent on estuaries to some degree. Two discrete demersal fish assemblages were identified representing the marine nearshore and the estuary, with no significant differences observed between the two estuaries (Sundays and Swartkops). The differences observed between the marine nearshore and estuary were mostly driven by salinity, turbidity, silt and organic content of the sediment. These distinct fish assemblages might be considered as indicators for the respective environments they inhabit. Both habitats were dominated by early life history stages (larvae to juveniles), indicating the nursery function of both habitats. Early life stages collectively comprised 97% of the catch in the marine nearshore and 68% in the estuary. Young-of-the-year (YOY) juveniles (< 1-year-old juveniles) and transformation stages (when changes in body shape and pigment pattern occur) dominated the total catch in the marine nearshore, while YOY juveniles dominated the estuarine fish assemblages. Ariidae Galeichthys feliceps, Haemulidae Pomadasys olivaceus, Sciaenidae Argyrosomus inodorus and Cynoglossidae Cynoglossus zanzibarensis, comprised the largest proportion of YOY juveniles in the marine nearshore. The transformation stage in the marine nearshore was numerically dominated by P. olivaceus and G. feliceps. In the estuarine environment, YOY juveniles were mostly dominated by Sparidae Rhabdosargus holubi, Soleidae Heteromycteris capensis and Gobiidae Caffrogobius gilchristi. The greatest abundance of early life stage fishes was observed in the lower reaches of the Sundays Estuary and the upper reaches of the Swartkops Estuary, as well as nearshore sites located in close proximity to the estuary mouths, particularly during spring and summer. Despite the fact that these coastal ecosystems are important nursery areas, they are threatened by a number of factors, including habitat loss and modification due to urban development, intensification of agriculture and subsequent eutrophication, climate change, and overfishing, all of which reduce ecosystem functioning and reduce the ecological and economic value of these habitats around the world. Hypoxia is one of the major threats to the functioning of coastal ecosystems, particularly estuaries. The Sundays and Swartkops estuaries both experience persistent eutrophic conditions, with frequent phytoplankton blooms (> 20 μg Chl-a l-1) that result in instances of bottom water oxygen depletion (< 4 mg/l). During the present study in the Sundays Estuary, low oxygen waters were recorded in the middle reaches (Site S5) mostly during summer (four months of low DO conditions). In the Swartkops Estuary, low dissolved oxygen was recorded in the upper reaches during spring. The lowest dissolved oxygen concentration recorded was 0.5 mg/l and 2.4 mg/l in the bottom waters of the Sundays and Swartkops estuaries, respectively. Selected dominant species were only absent from areas where dissolved oxygen was < 1 mg/l and present in the adjacent sites (for example Site S4, and S3) where DO was higher mostly during January 2019. As such, the low dissolved oxygen concentrations recorded in the Swartkops Estuary did not have a noticeable impact on fish distribution, although the total abundance of species did show a slight decline when dissolved oxygen was < 3 mg/l. This study demonstrates the importance of concurrently examining estuarine and nearshore marine habitats in order to identify ecologically important habitats, which has important implications for the development of effective management strategies for coastal fish populations, particularly in the light of anthropogenic change. In addition, in order to identify nursery hotspots it is crucial to correctly identify all the species occupying these areas. As such, this study confirms the importance of also using DNA barcoding for fish identification, particularly for the early life history stages of cryptic species (e.g. Argyrosomus inodorus and Argyrosomus japonicus). , Thesis (PhD) -- Faculty of Science, Ichthyology & Fisheries Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Design, synthesis, characterization and evaluation of Chitosan-based hydrogel for controlled drug delivery system
- Authors: Safari, Justin Bazibuhe
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232182 , vital:49969
- Description: Hepatitis B infection is a deadly infectious disease caused by the hepatitis B virus and is responsible for many deaths every year worldwide. Despite medication and vaccines against hepatitis B infection, it still presents high morbidity and mortality among populations. This is partly due to factors such as a long medication period of the existing treatments, resulting in poor patient compliance and leading to treatment failure. In addition, this situation can be responsible for the observed emerging drug resistance. Hence, novel drugs and drug delivery systems are needed to tackle this matter. Many strategies have been used to develop long-acting drug delivery systems treatment for several infectious diseases. Hydrogel drug delivery systems have shown interesting results as controlled drug delivery systems for several drugs. Therefore, the present study aimed to develop chitosan grafted poly (acrylamide-co-acrylic acid) hydrogel and apply it as a pH-sensitive controlled delivery system of tenofovir disoproxil fumarate (TDF). TDF is a nucleoside reverse transcriptase inhibitor used as first-line treatment of hepatitis B chronic infection and in the treatment of other viral infections. The free-radical polymerization method was utilized to modify chitosan by grafting acrylamide and acrylic acid and using N, N’-methylene bisacrylamide as the crosslinking agent to prepare the hydrogel, followed by an optimization of parameters that could affect the swelling capacity. The prepared chitosan-g-poly(acrylamide-co-acrylic acid) hydrogel was characterized using Fourier Transmission Infra-red spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermal Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Energy-dispersive X-ray spectroscopy (EDS), Scanning Electron Microscopy (SEM), and was evaluated for cytotoxicity using a HeLa cell assay. TDF was used as a drug model, it was loaded by the swelling equilibrium method, following by the investigation of the release profile of TDF-loaded hydrogel at pH 1.2 and 7.4. A successful synthesis of chitosan grafted poly(acrylamide-co-acrylic acid) hydrogel was confirmed by Fourier Transmission Infra-red spectroscopy (FTIR), X-Ray Diffraction Spectroscopy (XRD), Thermal Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Energy-dispersive X-ray spectroscopy (EDS) and Scanning Electron Microscopy (SEM). Optimization results showed that the ratio of monomers impacted the swelling ratio of the hydrogel and both the concentration of the crosslinking agent, and the reaction initiator also affected the swelling ratio. The synthesized hydrogels were sensitive to pH and ionic strength. Hydrogel swelling was lower in acidic solutions and higher in neutral and basic solutions and decreased with the increasing ionic strength. Furthermore, SEM results revealed that hydrogel have a rough and fibrous surface structure with numerous pores. Cytotoxicity studies demonstrated that the hydrogel was non-cytotoxic at 50 μg/ml against HeLa cells which suggested a good biocompatibility of the material. TDF was loaded and released from the hydrogels and showed an encapsulation efficiency and drug loading percentage ranging from 81-96% and 8-10%, respectively. TDF release profile was found to be low in buffer solution of pH 1.2 (in the range of 5-10%) and much higher (38-53%) at pH 7.4 within 96 hours. TDF maintained its chemical integrity after release and the hydrogels can therefore be proposed as a new controlled-release drug delivery system for hepatitis B treatment. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Safari, Justin Bazibuhe
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232182 , vital:49969
- Description: Hepatitis B infection is a deadly infectious disease caused by the hepatitis B virus and is responsible for many deaths every year worldwide. Despite medication and vaccines against hepatitis B infection, it still presents high morbidity and mortality among populations. This is partly due to factors such as a long medication period of the existing treatments, resulting in poor patient compliance and leading to treatment failure. In addition, this situation can be responsible for the observed emerging drug resistance. Hence, novel drugs and drug delivery systems are needed to tackle this matter. Many strategies have been used to develop long-acting drug delivery systems treatment for several infectious diseases. Hydrogel drug delivery systems have shown interesting results as controlled drug delivery systems for several drugs. Therefore, the present study aimed to develop chitosan grafted poly (acrylamide-co-acrylic acid) hydrogel and apply it as a pH-sensitive controlled delivery system of tenofovir disoproxil fumarate (TDF). TDF is a nucleoside reverse transcriptase inhibitor used as first-line treatment of hepatitis B chronic infection and in the treatment of other viral infections. The free-radical polymerization method was utilized to modify chitosan by grafting acrylamide and acrylic acid and using N, N’-methylene bisacrylamide as the crosslinking agent to prepare the hydrogel, followed by an optimization of parameters that could affect the swelling capacity. The prepared chitosan-g-poly(acrylamide-co-acrylic acid) hydrogel was characterized using Fourier Transmission Infra-red spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermal Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Energy-dispersive X-ray spectroscopy (EDS), Scanning Electron Microscopy (SEM), and was evaluated for cytotoxicity using a HeLa cell assay. TDF was used as a drug model, it was loaded by the swelling equilibrium method, following by the investigation of the release profile of TDF-loaded hydrogel at pH 1.2 and 7.4. A successful synthesis of chitosan grafted poly(acrylamide-co-acrylic acid) hydrogel was confirmed by Fourier Transmission Infra-red spectroscopy (FTIR), X-Ray Diffraction Spectroscopy (XRD), Thermal Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Energy-dispersive X-ray spectroscopy (EDS) and Scanning Electron Microscopy (SEM). Optimization results showed that the ratio of monomers impacted the swelling ratio of the hydrogel and both the concentration of the crosslinking agent, and the reaction initiator also affected the swelling ratio. The synthesized hydrogels were sensitive to pH and ionic strength. Hydrogel swelling was lower in acidic solutions and higher in neutral and basic solutions and decreased with the increasing ionic strength. Furthermore, SEM results revealed that hydrogel have a rough and fibrous surface structure with numerous pores. Cytotoxicity studies demonstrated that the hydrogel was non-cytotoxic at 50 μg/ml against HeLa cells which suggested a good biocompatibility of the material. TDF was loaded and released from the hydrogels and showed an encapsulation efficiency and drug loading percentage ranging from 81-96% and 8-10%, respectively. TDF release profile was found to be low in buffer solution of pH 1.2 (in the range of 5-10%) and much higher (38-53%) at pH 7.4 within 96 hours. TDF maintained its chemical integrity after release and the hydrogels can therefore be proposed as a new controlled-release drug delivery system for hepatitis B treatment. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04
Diski 9 Nine and Other Stories (and Things)
- Authors: Mahlabe, Stoffel
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232283 , vital:49978
- Description: My thesis is a collection of short stories that reflects the everyday lives of ordinary people. They touch on issues of morality within the current context, in such a way as to both entertain and educate. As a child I learned to imitate the wildly comical, sometimes dark dinoonwane and dithamalakwane stories I heard from elders. In my thesis, I draw on Amos Tutuola’s exuberant style of retelling Yoruba folktales and balance this with the languid candour of Jose Saramago’s Blindness. Stories such as Bessora’s The Milka Cow, and Micah Dean Hicks’s Crawfish Noon have impressed me deeply for their incredible, wild narrative strategies that still, however, emulate realism. Dambudzo Marechera and Can Themba are also present influences. Both have sprinklings of erudition in their writing, but in an earthy kind of way. Their writing contains transliterations that have a ring of the vernacular languages, an idiom that Africanises the English language. , Thesis (MA) -- Faculty of Humanities, School of Languages, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Mahlabe, Stoffel
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232283 , vital:49978
- Description: My thesis is a collection of short stories that reflects the everyday lives of ordinary people. They touch on issues of morality within the current context, in such a way as to both entertain and educate. As a child I learned to imitate the wildly comical, sometimes dark dinoonwane and dithamalakwane stories I heard from elders. In my thesis, I draw on Amos Tutuola’s exuberant style of retelling Yoruba folktales and balance this with the languid candour of Jose Saramago’s Blindness. Stories such as Bessora’s The Milka Cow, and Micah Dean Hicks’s Crawfish Noon have impressed me deeply for their incredible, wild narrative strategies that still, however, emulate realism. Dambudzo Marechera and Can Themba are also present influences. Both have sprinklings of erudition in their writing, but in an earthy kind of way. Their writing contains transliterations that have a ring of the vernacular languages, an idiom that Africanises the English language. , Thesis (MA) -- Faculty of Humanities, School of Languages, 2022
- Full Text:
- Date Issued: 2022-04
Effects of hydraulic fracking fluid on soil microbial composition and diversity
- Authors: Sianyuka, Nicolette
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232366 , vital:49985
- Description: Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Sianyuka, Nicolette
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232366 , vital:49985
- Description: Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-04
Environmental governance, agency and multi-actor dynamics in Southern Africa
- Authors: Falayi, Menelisi
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232355 , vital:49984 , DOI 10.21504/10962/232355
- Description: Natural resources have, since the beginning of time, played a central role in supporting human wellbeing. In southern Africa resource consumption has drastically increased over the past 50 years, resulting in biodiversity loss and land degradation. To reduce land degradation and biodiversity loss rates in the region, great emphasis has been placed on building effective governance structures that can deliver environmentally and socially sustainable outcomes. However, environmental governance continues to be a major challenge in the management and conservation of natural resources in the region. Thus, there is renewed scientific and policy interest in strengthening the capacity of governance systems. This thesis is timely; there is an increasing desire by policymakers and land users in the region to develop governance options that enhance multi-actor participation and collaboration. Therefore, this thesis explores the dynamics that influence the capacity of natural resource governance systems in southern Africa, predominately in Machubeni, South Africa (chapters 3 and 4) and in State forests in Zimbabwe (chapter 5). To achieve this aim, four stand-alone manuscripts that answer the following questions are included: 1. How have governance challenges manifested in natural resource management between 2010 and 2020 in southern Africa? 2. How were the governance objectives and attributes applied per historical period and what were the influencing drivers? a. What key drivers influenced rangeland condition over time in Machubeni? 3. How have multi-actor ties changed since the external investment in landscape governance and management in Machubeni, South Africa? 4. What role has agency played in the effectiveness of co-management initiatives in southern Africa? To answer the questions, I applied Bennett and Satterfield’s practical framework for understanding the objectives, attributes and elements of governance and Archer’s ii morphogenetic framework. The study employed a mixed-methods approach which included a scoping review methodology (chapter 2), household surveys, historical records, life history interviews, focus group discussions (chapters 3 and 4), social network analysis (chapter 4) and secondary data analysis (chapter 5). Results from the scoping review (chapter 2) show that research on governance challenges has not increased since 2010. Results suggest that governance challenges related to the maintenance of system integrity and functioning, specifically lack of coordination, accountability, skills, and resources to define effective natural resource management, were the most reported in the literature. Chapter 3 elucidates the importance of history in evaluating the application of governance objectives and rangeland condition in resource-poor areas. The results show that the residual impacts of the ‘ghost of environmental history’ still influence governance dynamics in Machubeni, South Africa. Furthermore, contemporary challenges are linked to history. Chapter 4 shows that transformative spaces enhance collaboration and knowledge sharing between land users, government, and researchers. Finally, chapter 5 employs the morphogenetic framework to assess how agency (the capacity of people and organisations to make choices and decisions about their lives) influenced the effectiveness of co-management initiatives in southern Africa. The results suggest that in attempts to shift governance towards greater effectiveness, more attention should be paid to building individual and group agency. Based on the results from the empirical chapters, the study identified three key focus areas that require more attention in order to build effective landscape governance and management in southern Africa:(i) acknowledging the role of historical legacies and context,(ii) building and developing agency, capacity and trust amongst actors and (iii) the development of sustainable landscape financing mechanisms that will enable governance systems to deliver socially and environmentally sustainable outcomes. , Ubutyebi bendalo buqhubekile budlala indima ebalulekileyo ekuxhaseni impilo-ntle yoluntu. Ngenxa yokubaluleka kobutyebi bendalo kubomi babantu, ukusetyenziswa kobutyebi kuye kwanda kakhulu kule minyaka eyi-50 idlulileyo, okubangela ulahleko lweentlobo-ntlobo yezityalo nezilwanyana eziphilayo kunye nokhukhuliseko komhlaba kumazantsi e-Afrika. Ukunciphisa ukhukhuliseko komhlaba kunye namazinga alahleko eentlobo-ntlobo zezityalo nezilwanyana eziphilayo kummandla, ugxininiso olukhulu luye lwabekwa ekwakhiweni kweziseko zolawulo ezisebenzayo ezinokuzisa iziphumo ezizinzileyo ngokwemeko yendalo nentlalo. Nangona kunjalo, ulawulo lwendalo lusaqhubeka lungumceli mngeni omkhulu kulawulo nolondolozo lobutyebi bendalo kulo mmandla. Ngoko ke, kukho umdla ohlaziyiweyo wenzululwazi nomgaqo-nkqubo ekomelezeni isakhono seenkqubo zolawulo. Le ithisisi ifike ngexesha kuba kukho umnqweno okhulayo kummandla ngabaqulunqi bomgaqo-nkqubo kunye nabasebenzisi bomhlaba ukuphuhlisa iinketho zolawulo eziphakamisa ukuthatha inxaxheba kwabantu abaninzi kunye nentsebenziswano. Ke ngoko, le ithisisi iphonononga izinto eziphembelela isakhono seenkqubo zolawulo lobutyebi bendalo kumazantsi eAfrika, ikakhulu eMachubeni, eMzantsi Afrika (isahluko 3 no 4) nakumahlathi kaRhulumente eZimbabwe (isahluko 5). Ukuphumeza le njongo, kufakwe layo: 1. Ibonakaliswe njani imiceli mngeni yolawulo kulawulo lwendalo phakathi ko-2010 no 2020 kumazantsi eAfrika? 2. Zeziphi injongo zolawulo kunye neempawu ezisetyenzisiweyo ngokwexesha lembali? a. Zeziphi ezona zinto eziqhuba phambili eziphembelele ukusetyenziswa kweenjongo zolawulo kunye neempawu ngokuhamba kwexesha? b. Zeziphi iindlela ezibalulekileyo ezichaphazele ngayo iimeko zamadlelo ekuhambeni kwexesha? 3. Atshintshe njani amakhonkco obudlelwane phakathi kwabathathi-nxaxheba ukusukela oko kutyalo-mali lwangaphandle kulawulo lobume bomhlaba eMachubeni, eMzantsi Afrika? 4. Yiyiphi indima edlalwe sisakhono sokwenza ukhetho kunye nezigqibo malunga nobomi bakho ekusebenzeni ngempumelelo kwamalinge olawulo ngokubambisana kumazantsi e-Afrika? Ukuphendula imibuzo, ndisebenzise isakhelo esisebenzayo sikaBennett kunye noSatterfield ukuqonda iinjongo kunye neempawu zolawulo kunye nesakhelo se-Archer's morphogenetic. Uphononongo lusebenzise iindlela ezixubeneyo ezibandakanya indlela yokuphonononga iincwadi zophando (isahluko 2), uphando lwamakhaya, iirekhodi zembali, udliwano-ndlebe lwembali yobomi, iingxoxo zeqela eligxininisiweyo (isahluko 3 kunye no 4), uhlalutyo lonxibelelwano nobudlelwane boluntu (isahluko 4) kunye nohlalutyo lwedatha ethathwe ngomnye umntu. (isahluko 5). Iziphumo ezivela kuphononongo lweencwadi zophando (isahluko 2) zibonakalisa ukuba uphando ngemiceli mngeni yolawulo alunyukanga ukusukela ngo-2010. Iziphumo zibonisa ukuba imiceli mngeni yolawulo enxulumene nokugcinwa kwemfezeko nokusebenza kwenkqubo, ngokukodwa ukungabikho kolungelelwaniso, uxanduva, izakhono, kunye nezibonelelo zokuchaza ulawulo lwemithombo yendalo olusebenzayo, yayiyeyona ichazwe kwiincwadi. Isahluko sesi-3 sicacisa ukubaluleka kwembali ekuvavanyeni ukusetyenziswa kweenjongo zolawulo kunye nemeko yemihlaba ekwiindawo ezihlwempuzekileyo ngezibonelelo. Iziphumo zibonisa ukuba uchaphazeleko oshiyekileyo we-‘ghost of environmental history’ zisenefuthe kulawulo lwenguquko eMachubeni, eMzantsi Afrika. Ngaphezu koko, imiceli mngeni yangoku inxulunyaniswa nembali. Isahluko sesi-4 sibonisa ukuba iindawo eziguqulayo ziphucula intsebenziswano nokwabelana ngolwazi phakathi kwabasebenzisi bomhlaba, urhulumente nabaphandi. Ekugqibeleni, isahluko sesi-5 sisebenzisa isakhelo se-morphogenetic ukuvavanya indlela isakhono sabantu kunye nemibutho sokwenza ukhetho kunye nezigqibo malunga nobomi babo ibe nefuthe ekusebenzeni kwamanyathelo olawulo ngokubambisana kumazantsi e-Afrika. Iziphumo zibonisa ukuba kwiinzame zokutshintsha ulawulo ukuze lusebenze kangangoko, ingqwalasela engaphezulu kufuneka ibekwe ekwakheni isakhono, somntu neseqela, sokwenza ukhetho kunye nezigqibo malunga nobomi babo. Ngokusekelwe kwiziphumo ezivela kwizahluko zobungqina, uphononongo luchonge imiba emithathu engundoqo ekugxilwe kuzo ezifuna ingqwalaselo ethe kratya ukuze kwakhiwe ulawulo lwemihlaba olusebenzayo kumazantsi e-Afrika. Ngokukodwa: (i) ukuqaphela indima yelifa lembali kunye nomxholo (ii) ukwakha nokuphuhlisa isakhono v sokwenza ukhetho kunye nezigqibo malunga nobomi, isakhono kunye nokuthembana phakathi kwabathathi-nxaxheba kunye (iii) nokuphuhliswa kweendlela ezizinzileyo zenkxaso-mali yendawo eziya kwenza ukuba iinkqubo zolawulo zinike iziphumo ezizinzileyo ngokwentlalo nendalo. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Falayi, Menelisi
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232355 , vital:49984 , DOI 10.21504/10962/232355
- Description: Natural resources have, since the beginning of time, played a central role in supporting human wellbeing. In southern Africa resource consumption has drastically increased over the past 50 years, resulting in biodiversity loss and land degradation. To reduce land degradation and biodiversity loss rates in the region, great emphasis has been placed on building effective governance structures that can deliver environmentally and socially sustainable outcomes. However, environmental governance continues to be a major challenge in the management and conservation of natural resources in the region. Thus, there is renewed scientific and policy interest in strengthening the capacity of governance systems. This thesis is timely; there is an increasing desire by policymakers and land users in the region to develop governance options that enhance multi-actor participation and collaboration. Therefore, this thesis explores the dynamics that influence the capacity of natural resource governance systems in southern Africa, predominately in Machubeni, South Africa (chapters 3 and 4) and in State forests in Zimbabwe (chapter 5). To achieve this aim, four stand-alone manuscripts that answer the following questions are included: 1. How have governance challenges manifested in natural resource management between 2010 and 2020 in southern Africa? 2. How were the governance objectives and attributes applied per historical period and what were the influencing drivers? a. What key drivers influenced rangeland condition over time in Machubeni? 3. How have multi-actor ties changed since the external investment in landscape governance and management in Machubeni, South Africa? 4. What role has agency played in the effectiveness of co-management initiatives in southern Africa? To answer the questions, I applied Bennett and Satterfield’s practical framework for understanding the objectives, attributes and elements of governance and Archer’s ii morphogenetic framework. The study employed a mixed-methods approach which included a scoping review methodology (chapter 2), household surveys, historical records, life history interviews, focus group discussions (chapters 3 and 4), social network analysis (chapter 4) and secondary data analysis (chapter 5). Results from the scoping review (chapter 2) show that research on governance challenges has not increased since 2010. Results suggest that governance challenges related to the maintenance of system integrity and functioning, specifically lack of coordination, accountability, skills, and resources to define effective natural resource management, were the most reported in the literature. Chapter 3 elucidates the importance of history in evaluating the application of governance objectives and rangeland condition in resource-poor areas. The results show that the residual impacts of the ‘ghost of environmental history’ still influence governance dynamics in Machubeni, South Africa. Furthermore, contemporary challenges are linked to history. Chapter 4 shows that transformative spaces enhance collaboration and knowledge sharing between land users, government, and researchers. Finally, chapter 5 employs the morphogenetic framework to assess how agency (the capacity of people and organisations to make choices and decisions about their lives) influenced the effectiveness of co-management initiatives in southern Africa. The results suggest that in attempts to shift governance towards greater effectiveness, more attention should be paid to building individual and group agency. Based on the results from the empirical chapters, the study identified three key focus areas that require more attention in order to build effective landscape governance and management in southern Africa:(i) acknowledging the role of historical legacies and context,(ii) building and developing agency, capacity and trust amongst actors and (iii) the development of sustainable landscape financing mechanisms that will enable governance systems to deliver socially and environmentally sustainable outcomes. , Ubutyebi bendalo buqhubekile budlala indima ebalulekileyo ekuxhaseni impilo-ntle yoluntu. Ngenxa yokubaluleka kobutyebi bendalo kubomi babantu, ukusetyenziswa kobutyebi kuye kwanda kakhulu kule minyaka eyi-50 idlulileyo, okubangela ulahleko lweentlobo-ntlobo yezityalo nezilwanyana eziphilayo kunye nokhukhuliseko komhlaba kumazantsi e-Afrika. Ukunciphisa ukhukhuliseko komhlaba kunye namazinga alahleko eentlobo-ntlobo zezityalo nezilwanyana eziphilayo kummandla, ugxininiso olukhulu luye lwabekwa ekwakhiweni kweziseko zolawulo ezisebenzayo ezinokuzisa iziphumo ezizinzileyo ngokwemeko yendalo nentlalo. Nangona kunjalo, ulawulo lwendalo lusaqhubeka lungumceli mngeni omkhulu kulawulo nolondolozo lobutyebi bendalo kulo mmandla. Ngoko ke, kukho umdla ohlaziyiweyo wenzululwazi nomgaqo-nkqubo ekomelezeni isakhono seenkqubo zolawulo. Le ithisisi ifike ngexesha kuba kukho umnqweno okhulayo kummandla ngabaqulunqi bomgaqo-nkqubo kunye nabasebenzisi bomhlaba ukuphuhlisa iinketho zolawulo eziphakamisa ukuthatha inxaxheba kwabantu abaninzi kunye nentsebenziswano. Ke ngoko, le ithisisi iphonononga izinto eziphembelela isakhono seenkqubo zolawulo lobutyebi bendalo kumazantsi eAfrika, ikakhulu eMachubeni, eMzantsi Afrika (isahluko 3 no 4) nakumahlathi kaRhulumente eZimbabwe (isahluko 5). Ukuphumeza le njongo, kufakwe layo: 1. Ibonakaliswe njani imiceli mngeni yolawulo kulawulo lwendalo phakathi ko-2010 no 2020 kumazantsi eAfrika? 2. Zeziphi injongo zolawulo kunye neempawu ezisetyenzisiweyo ngokwexesha lembali? a. Zeziphi ezona zinto eziqhuba phambili eziphembelele ukusetyenziswa kweenjongo zolawulo kunye neempawu ngokuhamba kwexesha? b. Zeziphi iindlela ezibalulekileyo ezichaphazele ngayo iimeko zamadlelo ekuhambeni kwexesha? 3. Atshintshe njani amakhonkco obudlelwane phakathi kwabathathi-nxaxheba ukusukela oko kutyalo-mali lwangaphandle kulawulo lobume bomhlaba eMachubeni, eMzantsi Afrika? 4. Yiyiphi indima edlalwe sisakhono sokwenza ukhetho kunye nezigqibo malunga nobomi bakho ekusebenzeni ngempumelelo kwamalinge olawulo ngokubambisana kumazantsi e-Afrika? Ukuphendula imibuzo, ndisebenzise isakhelo esisebenzayo sikaBennett kunye noSatterfield ukuqonda iinjongo kunye neempawu zolawulo kunye nesakhelo se-Archer's morphogenetic. Uphononongo lusebenzise iindlela ezixubeneyo ezibandakanya indlela yokuphonononga iincwadi zophando (isahluko 2), uphando lwamakhaya, iirekhodi zembali, udliwano-ndlebe lwembali yobomi, iingxoxo zeqela eligxininisiweyo (isahluko 3 kunye no 4), uhlalutyo lonxibelelwano nobudlelwane boluntu (isahluko 4) kunye nohlalutyo lwedatha ethathwe ngomnye umntu. (isahluko 5). Iziphumo ezivela kuphononongo lweencwadi zophando (isahluko 2) zibonakalisa ukuba uphando ngemiceli mngeni yolawulo alunyukanga ukusukela ngo-2010. Iziphumo zibonisa ukuba imiceli mngeni yolawulo enxulumene nokugcinwa kwemfezeko nokusebenza kwenkqubo, ngokukodwa ukungabikho kolungelelwaniso, uxanduva, izakhono, kunye nezibonelelo zokuchaza ulawulo lwemithombo yendalo olusebenzayo, yayiyeyona ichazwe kwiincwadi. Isahluko sesi-3 sicacisa ukubaluleka kwembali ekuvavanyeni ukusetyenziswa kweenjongo zolawulo kunye nemeko yemihlaba ekwiindawo ezihlwempuzekileyo ngezibonelelo. Iziphumo zibonisa ukuba uchaphazeleko oshiyekileyo we-‘ghost of environmental history’ zisenefuthe kulawulo lwenguquko eMachubeni, eMzantsi Afrika. Ngaphezu koko, imiceli mngeni yangoku inxulunyaniswa nembali. Isahluko sesi-4 sibonisa ukuba iindawo eziguqulayo ziphucula intsebenziswano nokwabelana ngolwazi phakathi kwabasebenzisi bomhlaba, urhulumente nabaphandi. Ekugqibeleni, isahluko sesi-5 sisebenzisa isakhelo se-morphogenetic ukuvavanya indlela isakhono sabantu kunye nemibutho sokwenza ukhetho kunye nezigqibo malunga nobomi babo ibe nefuthe ekusebenzeni kwamanyathelo olawulo ngokubambisana kumazantsi e-Afrika. Iziphumo zibonisa ukuba kwiinzame zokutshintsha ulawulo ukuze lusebenze kangangoko, ingqwalasela engaphezulu kufuneka ibekwe ekwakheni isakhono, somntu neseqela, sokwenza ukhetho kunye nezigqibo malunga nobomi babo. Ngokusekelwe kwiziphumo ezivela kwizahluko zobungqina, uphononongo luchonge imiba emithathu engundoqo ekugxilwe kuzo ezifuna ingqwalaselo ethe kratya ukuze kwakhiwe ulawulo lwemihlaba olusebenzayo kumazantsi e-Afrika. Ngokukodwa: (i) ukuqaphela indima yelifa lembali kunye nomxholo (ii) ukwakha nokuphuhlisa isakhono v sokwenza ukhetho kunye nezigqibo malunga nobomi, isakhono kunye nokuthembana phakathi kwabathathi-nxaxheba kunye (iii) nokuphuhliswa kweendlela ezizinzileyo zenkxaso-mali yendawo eziya kwenza ukuba iinkqubo zolawulo zinike iziphumo ezizinzileyo ngokwentlalo nendalo. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2022
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- Date Issued: 2022-04