The role of Facebook in a survivor’s post-assault life: rape on campuses, women activists, and mental health
- Authors: Witi, Sinethemba Juliet
- Date: 2022-10-14
- Subjects: Online social networks , Rape in universities and colleges South Africa Makhanda , Student movements South Africa Makhanda , College students Mental health South Africa Makhanda , Sex crimes South Africa Makhanda , Social media and college students South Africa Makhanda , Intersectionality (Sociology) , Womanism
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405952 , vital:70222
- Description: The rise of Social Networking Sites (SNSs) has raised concerns about the negative impact social media platforms, and in particular Facebook, has on their users. Research has linked the excessive use of Facebook with mental health challenges such as loneliness, depression, and stress. This research examined how Yolanda Dyantyi, a gender rights activist registered as a student from 2015 to 2017 at Rhodes University, used Facebook as an outlet following the #RUreferencelist protests and her subsequent permanent exclusion from the institution for her role in the protests. The study explored Dyanti’s use of Facebook, examining in particular her ongoing activism, her mental health challenges, and her struggles to re-establish herself in a community after the exclusion from Rhodes. The study employed an intersectional feminist theoretical framework and drew on a qualitative content analysis, a semi-structured interview, and the scroll back method to review the Facebook posts she had made. A thematic analysis of the data showed that Dyantyi is a multifaceted, and evolving Facebook user and contrary to existing research her prolific use of Facebook has had positive effects on her mental health and has enabled her to build social capital. The study suggests that activism is an important component to research alongside studies of mental health on such media platforms. , Thesis (MA) -- Faculty of Humanities, School of Journalism and Media Studies, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Witi, Sinethemba Juliet
- Date: 2022-10-14
- Subjects: Online social networks , Rape in universities and colleges South Africa Makhanda , Student movements South Africa Makhanda , College students Mental health South Africa Makhanda , Sex crimes South Africa Makhanda , Social media and college students South Africa Makhanda , Intersectionality (Sociology) , Womanism
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405952 , vital:70222
- Description: The rise of Social Networking Sites (SNSs) has raised concerns about the negative impact social media platforms, and in particular Facebook, has on their users. Research has linked the excessive use of Facebook with mental health challenges such as loneliness, depression, and stress. This research examined how Yolanda Dyantyi, a gender rights activist registered as a student from 2015 to 2017 at Rhodes University, used Facebook as an outlet following the #RUreferencelist protests and her subsequent permanent exclusion from the institution for her role in the protests. The study explored Dyanti’s use of Facebook, examining in particular her ongoing activism, her mental health challenges, and her struggles to re-establish herself in a community after the exclusion from Rhodes. The study employed an intersectional feminist theoretical framework and drew on a qualitative content analysis, a semi-structured interview, and the scroll back method to review the Facebook posts she had made. A thematic analysis of the data showed that Dyantyi is a multifaceted, and evolving Facebook user and contrary to existing research her prolific use of Facebook has had positive effects on her mental health and has enabled her to build social capital. The study suggests that activism is an important component to research alongside studies of mental health on such media platforms. , Thesis (MA) -- Faculty of Humanities, School of Journalism and Media Studies, 2022
- Full Text:
- Date Issued: 2022-10-14
An investigation into stakeholder inclusivity and the board’s ability to create competitive advantage at South Africa’s “big five” retail banks
- Authors: Wolhuter, Darren Wilfred
- Date: 2022-04-06
- Subjects: Stakeholder management South Africa , Strategic planning South Africa , Banks and banking South Africa , Corporate governance South Africa , Competition , Resource-based theory
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284548 , vital:56073
- Description: Stakeholder theory has long put forth the concept that managerial attention must be given to all stakeholders towards the realisation of value creation opportunities. Through the process of stakeholder engagement, and through the adoption of stakeholder inclusivity principles, an organisation can position itself to reap the benefits of understanding the legitimate needs and interests of all its stakeholders by seeking to satisfy all its stakeholders in turn. This study analysed the integrated reports of five retail banks, whose main base of operations were in South Africa, to assess the board’s ability to create value for its stakeholders through adopting a stakeholder inclusive approach to corporate governance as advocated for by the King Code on Corporate Governance in South Africa – King IV™. This assessment was done through an examination of a selection of outcomes relevant to the banking industry and related to each of the six capitals that form part of the value creation process as indicated for in the Integrated Reporting Framework (IIRC, 2013): 1) Financial Capital, 2) Manufactured Capital; 3) Intellectual Capital; 4) Human Capital; 5) Social and Relationship Capital, and; 6) Natural Capital. The results obtained, over a three-year period – 2018 to 2020, revealed that while the directors had a firm understanding of who their material stakeholders were, they struggled to create value that catered to all their stakeholders collectively. In addition, the directors were also unable to create sustainable value over the assessment period. As a result of this, most banks, with the exception of one, were unable to realise the value creation opportunities that could have led to a potential source of competitive advantage. The study concludes that while no observable sustainable competitive advantage was evident over the period of assessment, the concept of stakeholder inclusivity is an important corporate governance principle that drives value creation and, as such, warrants more attention from the director’s point of view. This research is intended to contribute to the growing knowledge on the importance of stakeholder inclusivity in corporate governance execution. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Wolhuter, Darren Wilfred
- Date: 2022-04-06
- Subjects: Stakeholder management South Africa , Strategic planning South Africa , Banks and banking South Africa , Corporate governance South Africa , Competition , Resource-based theory
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284548 , vital:56073
- Description: Stakeholder theory has long put forth the concept that managerial attention must be given to all stakeholders towards the realisation of value creation opportunities. Through the process of stakeholder engagement, and through the adoption of stakeholder inclusivity principles, an organisation can position itself to reap the benefits of understanding the legitimate needs and interests of all its stakeholders by seeking to satisfy all its stakeholders in turn. This study analysed the integrated reports of five retail banks, whose main base of operations were in South Africa, to assess the board’s ability to create value for its stakeholders through adopting a stakeholder inclusive approach to corporate governance as advocated for by the King Code on Corporate Governance in South Africa – King IV™. This assessment was done through an examination of a selection of outcomes relevant to the banking industry and related to each of the six capitals that form part of the value creation process as indicated for in the Integrated Reporting Framework (IIRC, 2013): 1) Financial Capital, 2) Manufactured Capital; 3) Intellectual Capital; 4) Human Capital; 5) Social and Relationship Capital, and; 6) Natural Capital. The results obtained, over a three-year period – 2018 to 2020, revealed that while the directors had a firm understanding of who their material stakeholders were, they struggled to create value that catered to all their stakeholders collectively. In addition, the directors were also unable to create sustainable value over the assessment period. As a result of this, most banks, with the exception of one, were unable to realise the value creation opportunities that could have led to a potential source of competitive advantage. The study concludes that while no observable sustainable competitive advantage was evident over the period of assessment, the concept of stakeholder inclusivity is an important corporate governance principle that drives value creation and, as such, warrants more attention from the director’s point of view. This research is intended to contribute to the growing knowledge on the importance of stakeholder inclusivity in corporate governance execution. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
- Full Text:
- Date Issued: 2022-04-06
Quantifying feed intake and feeding intensity using two experimental conditions and the effect of different feeding strategies on the production parameters of farmed South African abalone, haliotis midae
- Authors: Wortley, Ross Michael
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/${Handle} , vital:71932
- Description: As abalone are slow-growing animals there is a high investment of capital, running costs and labour in commercial abalone farming. Revenue needs to be maximised by achieving fast growth rates. A foremost driver of abalone growth is feed intake and feeding intensity of the abalone as well as the feeding regimen a farm utilises. While feed intake is well-documented in H. midae, there is a paucity of information regarding this aspect in abalone above 70 g and the relationship between feeding intensity, feed conversion rate (FCR) and daily growth rate needs to be documented. Similarly, there are a limited number of studies dealing with the effects of different pellet types of the same formulation, that differ only in shape and size, on feed intake and production in H. midae. This study made use of both a controlled laboratory experiment and commercial-scale farm experiment with the aim of testing whether feed intake information produced under laboratory conditions can provide good estimates of feed intake under farming conditions, which can further be implemented into feeding strategies on abalone farms. This study quantified daily feed intake (F) in 10 – 20 g, 100 – 110 g and 150 – 160 g abalone weight classes using two different pellet types and determined the relationship between the duration of feed availability and feed intake under laboratory conditions. The effect of three different pellet type strategies (fed daily: a leaf-only strategy = L d-1, a short-pellet only strategy = SP d-1, and a strategy that used both = B d-1) on abalone production parameters under farming conditions such as growth rate, feed conversion ratio (FCR), feeding intensity (FI) and weight variation of 30 – 40 g H. midae was also investigated. A commercial-scale farm study was designed to test the effect of four commercially relevant feeding regimens (three size-specific regimens and one commercially practiced feeding method) on the growth, FCR, feeding intensity and weight variation of these three abalone weight classes while taking into account an economic model to assess the profitability of each feeding regimen. Daily feed intake as a percentage of body mass (% BM d-1) was a function of abalone weight class between the 10 – 20 g and two larger weight classes 100 – 110 g and 150 – 160 g p < 0.0001), however feed intake was not different between the 100 – 110 g and 150 – 160 g weight classes. Pellet type did not affect feed intake in all abalone weight classes (p = 0.15). Feed intake (F) was positively linearly correlated with duration of feed availability (h) in the 10 – 20 g weight class (r2 = 0.76, p <0.00001) and logarithmically correlated in the 100 – 110 g (r2 = 0.25, p < 0.02) and 150 – 160 g (r2 = 0.52, p < 0.0001) weight classes (10 – 20 g abalone-1: 3 F (% BM) = 0.02(h) + 0.1976, 100 – 110 g abalone-1: F (% BM) = log10(h)*0.17 + 0.17, 150 – 160 g abalone-1: F (% BM) = log10(h)*0.36 + 0.07). There was no significant difference in monthly average abalone weight, daily growth rate (G), FCR and feeding intensity between each pellet type strategy (G: p = 0.60, FCR: p = 0.62, FI: p = 0.54 ). However, abalone grew well over the 112-day growth period with average abalone weight increasing significantly between each monthly sample time (pooled pellet type strategy: Huynh-Feldt correction; p < 0.00001). Furthermore, abalone fed the leaf-only pellet type strategy (L d-1) fell into higher weight classes after a 112-day growth period (Z test: 50 – 70 g: 72%) which was 16.1 % higher compared to the SP d-1 and B d-1 strategies. Daily growth rate (r2 = 0.34, p < 0.01) and FCR (r2 = 0.42, p < 0.004) was negatively correlated and FCR was positively correlated with daily feeding intensity, respectively (G = - 2.59 (FI) + 1.526, FCR = 8.8082 (FI) – 2.7108). Feeding regimen affected the production parameters of three abalone weight classes. The method practiced on the farm resulted in the best growth in the 10 – 20 g abalone weight class. The farm feeding method resulted in slower yet more efficient growth rates (lowest FCR values) in the abalone weight classes, 100 – 110 g and 150 – 160 g abalone- 1. However, size-specific feeding regimens resulted in the fastest growth rates but resulted in higher FCR values (less efficient). The relationship between feeding intensity, daily growth rate and FCR all showed that an increase in feeding intensity results in increased daily growth rates and FCR values. The economic model suggests that the higher FCR values associated with size-specific regimens, which have higher associated costs to producing abalone, were greatly outweighed by the growth attained by the abalone in the 100 – 110 g and 150 – 160 g weight classes. The size-specific regimens generated a higher potential monetary value of abalone after a 112-day period, which would consequently result in higher income for abalone farms. For abalone ranging from 100 – 110 and 150 – 160 grams, the economic model suggested that in a quarterly grading schedule (112 days) that abalone be fed the size specific daily rations, which is a function of body mass, at 0.35 % BM d-1 and 0.352 % BM d-1, respectively. The two experimental conditions used in this study produced feed intake and production parameter information that is beneficial to South African abalone farmers. The small-scale laboratory study produced information on feed intake that can be used as reference values as to what abalone in these weight classes can consume on a daily basis. The laboratory study can provide estimates of feed intake under farming conditions but should only be used as minimum 4 values when determining size-specific feeding regimens. To maximise abalone growth, farmers should utilise size-specific feeding regimens for abalone above 30 g. Daily growth rate and FCR can be predicted as a function of the abalone’s feeding intensity. Further studies are needed to determine the effects of abalone weight class on production parameters when testing different pellet types as well as an exploration into behavioural studies focusing on diet preferences. Additionally, future studies need to take into consideration abalone above the weight of 100 g with additional focus of research on behavioural, genetic and environmental aspects on abalone feed intake. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-03-29
- Authors: Wortley, Ross Michael
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/${Handle} , vital:71932
- Description: As abalone are slow-growing animals there is a high investment of capital, running costs and labour in commercial abalone farming. Revenue needs to be maximised by achieving fast growth rates. A foremost driver of abalone growth is feed intake and feeding intensity of the abalone as well as the feeding regimen a farm utilises. While feed intake is well-documented in H. midae, there is a paucity of information regarding this aspect in abalone above 70 g and the relationship between feeding intensity, feed conversion rate (FCR) and daily growth rate needs to be documented. Similarly, there are a limited number of studies dealing with the effects of different pellet types of the same formulation, that differ only in shape and size, on feed intake and production in H. midae. This study made use of both a controlled laboratory experiment and commercial-scale farm experiment with the aim of testing whether feed intake information produced under laboratory conditions can provide good estimates of feed intake under farming conditions, which can further be implemented into feeding strategies on abalone farms. This study quantified daily feed intake (F) in 10 – 20 g, 100 – 110 g and 150 – 160 g abalone weight classes using two different pellet types and determined the relationship between the duration of feed availability and feed intake under laboratory conditions. The effect of three different pellet type strategies (fed daily: a leaf-only strategy = L d-1, a short-pellet only strategy = SP d-1, and a strategy that used both = B d-1) on abalone production parameters under farming conditions such as growth rate, feed conversion ratio (FCR), feeding intensity (FI) and weight variation of 30 – 40 g H. midae was also investigated. A commercial-scale farm study was designed to test the effect of four commercially relevant feeding regimens (three size-specific regimens and one commercially practiced feeding method) on the growth, FCR, feeding intensity and weight variation of these three abalone weight classes while taking into account an economic model to assess the profitability of each feeding regimen. Daily feed intake as a percentage of body mass (% BM d-1) was a function of abalone weight class between the 10 – 20 g and two larger weight classes 100 – 110 g and 150 – 160 g p < 0.0001), however feed intake was not different between the 100 – 110 g and 150 – 160 g weight classes. Pellet type did not affect feed intake in all abalone weight classes (p = 0.15). Feed intake (F) was positively linearly correlated with duration of feed availability (h) in the 10 – 20 g weight class (r2 = 0.76, p <0.00001) and logarithmically correlated in the 100 – 110 g (r2 = 0.25, p < 0.02) and 150 – 160 g (r2 = 0.52, p < 0.0001) weight classes (10 – 20 g abalone-1: 3 F (% BM) = 0.02(h) + 0.1976, 100 – 110 g abalone-1: F (% BM) = log10(h)*0.17 + 0.17, 150 – 160 g abalone-1: F (% BM) = log10(h)*0.36 + 0.07). There was no significant difference in monthly average abalone weight, daily growth rate (G), FCR and feeding intensity between each pellet type strategy (G: p = 0.60, FCR: p = 0.62, FI: p = 0.54 ). However, abalone grew well over the 112-day growth period with average abalone weight increasing significantly between each monthly sample time (pooled pellet type strategy: Huynh-Feldt correction; p < 0.00001). Furthermore, abalone fed the leaf-only pellet type strategy (L d-1) fell into higher weight classes after a 112-day growth period (Z test: 50 – 70 g: 72%) which was 16.1 % higher compared to the SP d-1 and B d-1 strategies. Daily growth rate (r2 = 0.34, p < 0.01) and FCR (r2 = 0.42, p < 0.004) was negatively correlated and FCR was positively correlated with daily feeding intensity, respectively (G = - 2.59 (FI) + 1.526, FCR = 8.8082 (FI) – 2.7108). Feeding regimen affected the production parameters of three abalone weight classes. The method practiced on the farm resulted in the best growth in the 10 – 20 g abalone weight class. The farm feeding method resulted in slower yet more efficient growth rates (lowest FCR values) in the abalone weight classes, 100 – 110 g and 150 – 160 g abalone- 1. However, size-specific feeding regimens resulted in the fastest growth rates but resulted in higher FCR values (less efficient). The relationship between feeding intensity, daily growth rate and FCR all showed that an increase in feeding intensity results in increased daily growth rates and FCR values. The economic model suggests that the higher FCR values associated with size-specific regimens, which have higher associated costs to producing abalone, were greatly outweighed by the growth attained by the abalone in the 100 – 110 g and 150 – 160 g weight classes. The size-specific regimens generated a higher potential monetary value of abalone after a 112-day period, which would consequently result in higher income for abalone farms. For abalone ranging from 100 – 110 and 150 – 160 grams, the economic model suggested that in a quarterly grading schedule (112 days) that abalone be fed the size specific daily rations, which is a function of body mass, at 0.35 % BM d-1 and 0.352 % BM d-1, respectively. The two experimental conditions used in this study produced feed intake and production parameter information that is beneficial to South African abalone farmers. The small-scale laboratory study produced information on feed intake that can be used as reference values as to what abalone in these weight classes can consume on a daily basis. The laboratory study can provide estimates of feed intake under farming conditions but should only be used as minimum 4 values when determining size-specific feeding regimens. To maximise abalone growth, farmers should utilise size-specific feeding regimens for abalone above 30 g. Daily growth rate and FCR can be predicted as a function of the abalone’s feeding intensity. Further studies are needed to determine the effects of abalone weight class on production parameters when testing different pellet types as well as an exploration into behavioural studies focusing on diet preferences. Additionally, future studies need to take into consideration abalone above the weight of 100 g with additional focus of research on behavioural, genetic and environmental aspects on abalone feed intake. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-03-29
Philosophical inquiry into the value of liberal education
- Authors: Wotshela, Siphosihle
- Date: 2023-03-30
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408954 , vital:70540
- Description: Throughout history, scholars have offered numerous conceptions of liberal education, with each scholar providing a slightly and sometimes extremely different idea of what liberal education actually is, what it entails, and what value one stands to gain by partaking in this particular type of education. In this thesis, I inquire into the topic of liberal education in an attempt to clearly understand what value partaking in this type of education offers the contemporary South African. In the process, I offer a defence against what I refer to as the societal context problem—a problem that questions the possibility of a universal benefit that can be obtained by partaking in liberal education. I also offer a comprehensive argument for the preference of Jacob Klein’s conception of liberal education, making the claim that Klein’s conception and the value he identifies with his conception is more convincing than that offered by other scholars because Klein’s conception and the value associated with the conception is universal in a way that allows it to remain relevant even when confronted with the problem of societal context. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2023
- Full Text:
- Date Issued: 2023-03-30
- Authors: Wotshela, Siphosihle
- Date: 2023-03-30
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/408954 , vital:70540
- Description: Throughout history, scholars have offered numerous conceptions of liberal education, with each scholar providing a slightly and sometimes extremely different idea of what liberal education actually is, what it entails, and what value one stands to gain by partaking in this particular type of education. In this thesis, I inquire into the topic of liberal education in an attempt to clearly understand what value partaking in this type of education offers the contemporary South African. In the process, I offer a defence against what I refer to as the societal context problem—a problem that questions the possibility of a universal benefit that can be obtained by partaking in liberal education. I also offer a comprehensive argument for the preference of Jacob Klein’s conception of liberal education, making the claim that Klein’s conception and the value he identifies with his conception is more convincing than that offered by other scholars because Klein’s conception and the value associated with the conception is universal in a way that allows it to remain relevant even when confronted with the problem of societal context. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2023
- Full Text:
- Date Issued: 2023-03-30
Native-range studies on insect herbivores associated with African Lovegrass (Eragrostis curvula) in South Africa: prospects for biological control in Australia
- Authors: Yell, Liam Dougal
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424446 , vital:72154
- Description: Eragrostis curvula (Schrad.) Nees. (African Lovegrass) is an African native species of grass that was intentionally introduced for pasture in Australia. It has since escaped cultivation and has become widespread and highly invasive. Eragrostis curvula has been recorded in every state and territory in Australia where it has altered fire regimes, disrupted nutrient cycles and can reduce livestock carrying capacity by up to 50%. The Centre for Biological Control at Rhodes University and the New South Wales Department of Primary Industries have been working in collaboration to identify and screen herbivorous insects as biological control agents for E. curvula in Australia. Native-range surveys were conducted between 2021 and 2022 on E. curvula at twenty-two sites across South Africa to identify herbivorous natural enemies associated with it. Species accumulation curves were generated to ensure adequate sampling was performed to identify all the insects associated with E. curvula. Twenty-nine non-target grass species were surveyed simultaneously to determine the field-host range of the natural enemies associated with the target weed. Herbivorous natural enemies were prioritised as possible biological control agents against E. curvula in Australia based on field-host range, predicted efficacy and climatic suitability. Four insect species were consistently found on E. curvula, two of which were herbivorous, as well as a parasitoid and a detritivore. Species accumulation curves show that the insect community was adequately sampled in South Africa. The two herbivorous insects were identified to the lowest taxonomic level using COI barcoding. Both species are undescribed phytophagous wasps in the genus Tetramesa (Hymenoptera: Eurytomidae). Because Tetramesa species have been shown to be host specific and highly damaging in previous biological control programs for other invasive grass weeds, we assessed their suitability as candidate biological control agents for use on E. curvula in Australia. Both Tetramesa species (“sp. 4” and “sp. 5”) were found on several native congeners under field conditions in South Africa. Congeneric South African-native non-target grass species were used as phylogenetic proxies to assess the risk posed to Australian native Eragrostis species. This highlighted three non-target Australian native Eragrostis species, namely: E. parviflora (R. Br.) Trin., E. leptocarpa Benth. fl., and E. trachycarpa Benth., that are at risk of being attacked by the two candidate agents based on their phylogenetic proximity to E. curvula. Predicted efficacy trials were conducted at five long-term repeat survey sites and revealed that Tetramesa sp. 4 does not reduce the probability of E. curvula tiller survival or reproduction, while Tetramesa sp. 5 does not reduce the probability of tiller reproduction but does increase the probability of tiller survival. This result was unexpected and may be a plant compensatory response to herbivory. The sites where both Tetramesa species were collected in South Africa are climatically similar to the invaded range of E. curvula in Australia, and as such, the Tetramesa spp. are likely to be suitably adapted to the climate where they would be released in Australia. These results suggest that both Tetramesa species associated with E. curvula may have too broad a host range to be used as biological control agents in Australia. However, further quarantine-based host-range assessments on Australian native Eragrostis species are recommended to confirm this. The field-based methods used in this study have reduced the number of insect and plant species that host-range assessments will be required to be performed on, thus preventing wasted resources. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Yell, Liam Dougal
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424446 , vital:72154
- Description: Eragrostis curvula (Schrad.) Nees. (African Lovegrass) is an African native species of grass that was intentionally introduced for pasture in Australia. It has since escaped cultivation and has become widespread and highly invasive. Eragrostis curvula has been recorded in every state and territory in Australia where it has altered fire regimes, disrupted nutrient cycles and can reduce livestock carrying capacity by up to 50%. The Centre for Biological Control at Rhodes University and the New South Wales Department of Primary Industries have been working in collaboration to identify and screen herbivorous insects as biological control agents for E. curvula in Australia. Native-range surveys were conducted between 2021 and 2022 on E. curvula at twenty-two sites across South Africa to identify herbivorous natural enemies associated with it. Species accumulation curves were generated to ensure adequate sampling was performed to identify all the insects associated with E. curvula. Twenty-nine non-target grass species were surveyed simultaneously to determine the field-host range of the natural enemies associated with the target weed. Herbivorous natural enemies were prioritised as possible biological control agents against E. curvula in Australia based on field-host range, predicted efficacy and climatic suitability. Four insect species were consistently found on E. curvula, two of which were herbivorous, as well as a parasitoid and a detritivore. Species accumulation curves show that the insect community was adequately sampled in South Africa. The two herbivorous insects were identified to the lowest taxonomic level using COI barcoding. Both species are undescribed phytophagous wasps in the genus Tetramesa (Hymenoptera: Eurytomidae). Because Tetramesa species have been shown to be host specific and highly damaging in previous biological control programs for other invasive grass weeds, we assessed their suitability as candidate biological control agents for use on E. curvula in Australia. Both Tetramesa species (“sp. 4” and “sp. 5”) were found on several native congeners under field conditions in South Africa. Congeneric South African-native non-target grass species were used as phylogenetic proxies to assess the risk posed to Australian native Eragrostis species. This highlighted three non-target Australian native Eragrostis species, namely: E. parviflora (R. Br.) Trin., E. leptocarpa Benth. fl., and E. trachycarpa Benth., that are at risk of being attacked by the two candidate agents based on their phylogenetic proximity to E. curvula. Predicted efficacy trials were conducted at five long-term repeat survey sites and revealed that Tetramesa sp. 4 does not reduce the probability of E. curvula tiller survival or reproduction, while Tetramesa sp. 5 does not reduce the probability of tiller reproduction but does increase the probability of tiller survival. This result was unexpected and may be a plant compensatory response to herbivory. The sites where both Tetramesa species were collected in South Africa are climatically similar to the invaded range of E. curvula in Australia, and as such, the Tetramesa spp. are likely to be suitably adapted to the climate where they would be released in Australia. These results suggest that both Tetramesa species associated with E. curvula may have too broad a host range to be used as biological control agents in Australia. However, further quarantine-based host-range assessments on Australian native Eragrostis species are recommended to confirm this. The field-based methods used in this study have reduced the number of insect and plant species that host-range assessments will be required to be performed on, thus preventing wasted resources. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
- Full Text:
- Date Issued: 2023-10-13
Marine plastic pollution impacts on ecosystem services and livelihoods in South Africa: a review and stakeholder perceptions
- Authors: Yose, Papama
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424743 , vital:72180
- Description: Marine plastic pollution is one of the major environmental problems globally, with adverse impacts on marine ecosystem services, functions and benefits and people. Yet, compared to plastic pollution impacts on terrestrial ecosystems, the impacts of plastic waste on marine ecosystems are little studied and poorly understood in South Africa. In response, research interest on the ecological and economic impacts of marine plastic pollution has grown rapidly but socio-cultural impacts remain poorly conceptualized and little understudied. This trend is arguably driven by the dominance of a quantitative paradigm which is arguably inadequate to respond to dynamic socio-cultural issues and contexts. Further, in South Africa, marine ecosystems are used by diverse groups of people ranging from subsistence users, tourism operators, commercial fishers and recreational users, meaning that addressing marine plastic pollution requires a multi-stakeholder approach. However, few studies explore the perceptions of diverse stakeholders regarding marine plastic pollution, its impacts and potential interventions. Against this background, the objective of the thesis are twofold: (a) to argue for a more nuanced understanding of marine plastic pollution impacts on human well-being in order to strengthen conceptualization of impacts that goes beyond direct and quantitatively measured impacts (ecological, health and economic) but considers the socio-cultural dimensions of impacts (lifestyle disruptions, mental health costs and cultural and heritage impacts), and (b) examine stakeholders’ perceptions of marine plastic pollution, its impacts and potential interventions in South Africa. Drawing on case studies, this study provides a working definition of the socio-cultural impacts of marine plastic pollution and a conceptual framework for categorizing the impacts. It highlights three dimensions of the socio-cultural impacts of marine plastic pollution (lifestyle, mental health, and cultural and heritage impacts). It also illustrates connections between marine ecosystems and marine-based livelihood activities with the social and cultural dimensions of human wellbeing to show the links between marine environments and socio-cultural contexts. Concerning stakeholder perceptions, the study showed a tendency to associate marine plastic pollution with immediate, noticeable and easily quantifiable ecological impacts such as entanglement and ingestion of marine organisms, economic impacts and social impacts (e.g., loss of aesthetic appeal). However, secondary impacts such as loss of marine biodiversity and social impacts such as human health, were largely unknown. Moreover, there was heterogeneity in perceptions of marine plastic pollution impacts among the stakeholder groups. Prospective studies researching marine plastic pollution impacts should consider divergent and diverse perceptions of different stakeholders to capture the real costs of marine plastic pollution. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Yose, Papama
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424743 , vital:72180
- Description: Marine plastic pollution is one of the major environmental problems globally, with adverse impacts on marine ecosystem services, functions and benefits and people. Yet, compared to plastic pollution impacts on terrestrial ecosystems, the impacts of plastic waste on marine ecosystems are little studied and poorly understood in South Africa. In response, research interest on the ecological and economic impacts of marine plastic pollution has grown rapidly but socio-cultural impacts remain poorly conceptualized and little understudied. This trend is arguably driven by the dominance of a quantitative paradigm which is arguably inadequate to respond to dynamic socio-cultural issues and contexts. Further, in South Africa, marine ecosystems are used by diverse groups of people ranging from subsistence users, tourism operators, commercial fishers and recreational users, meaning that addressing marine plastic pollution requires a multi-stakeholder approach. However, few studies explore the perceptions of diverse stakeholders regarding marine plastic pollution, its impacts and potential interventions. Against this background, the objective of the thesis are twofold: (a) to argue for a more nuanced understanding of marine plastic pollution impacts on human well-being in order to strengthen conceptualization of impacts that goes beyond direct and quantitatively measured impacts (ecological, health and economic) but considers the socio-cultural dimensions of impacts (lifestyle disruptions, mental health costs and cultural and heritage impacts), and (b) examine stakeholders’ perceptions of marine plastic pollution, its impacts and potential interventions in South Africa. Drawing on case studies, this study provides a working definition of the socio-cultural impacts of marine plastic pollution and a conceptual framework for categorizing the impacts. It highlights three dimensions of the socio-cultural impacts of marine plastic pollution (lifestyle, mental health, and cultural and heritage impacts). It also illustrates connections between marine ecosystems and marine-based livelihood activities with the social and cultural dimensions of human wellbeing to show the links between marine environments and socio-cultural contexts. Concerning stakeholder perceptions, the study showed a tendency to associate marine plastic pollution with immediate, noticeable and easily quantifiable ecological impacts such as entanglement and ingestion of marine organisms, economic impacts and social impacts (e.g., loss of aesthetic appeal). However, secondary impacts such as loss of marine biodiversity and social impacts such as human health, were largely unknown. Moreover, there was heterogeneity in perceptions of marine plastic pollution impacts among the stakeholder groups. Prospective studies researching marine plastic pollution impacts should consider divergent and diverse perceptions of different stakeholders to capture the real costs of marine plastic pollution. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2023
- Full Text:
- Date Issued: 2023-10-13
In silico substrate binding profiling for SARS-COV-2 main protease (mpro) using hexapeptide substrates
- Authors: Zabo, Sophakama
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365566 , vital:65760
- Description: COVID-19, as a disease resulting from SARS-CoV-2 infection, and a pandemic has had a devastating effect on the world. There are limited effective measures that control the spread and treatment of COVID-19 illness. The homodimeric cysteine main protease (Mpro) is crucial to the life cycle of the virus, as it cleaves the large polyproteins 1a and 1ab into matured, functional non-structural proteins. The Mpro exhibits high degrees of conservation in sequence, structure and specificity across coronavirus species, making it an ideal drug target. The Mpro substrate-binding profiles remain, despite the resolution of its recognition sequence and cleavage points (Leu-Gln↓(Ser/Ala/Gly)). In this study, a series of hexapeptide sequences containing the appropriate recognition sequence and cleavage points were generated and screened against the Mpro to study these binding profiles, and to further be the basis for efficiency-driven drug design. A multi-conformer hexapeptide substrate library comprising optimised 81000 models of 810 unique sequences was generated using RDKit within the context of python. Terminal capping with ACE and NMe was effected using SMILES and SMARTS matching. Multiple hexapeptides were complexed with chain B of crystallographic Mpro (PDS ID: 6XHM), following the validation of chain B for this purpose using AutoDock Vina at high levels of exhaustiveness (480). The resulting Vina scores ranged between -8.7 and -7.0 kcal.mol-1, and the reproducibility of best poses was validated through redocking. Ligand efficiency indices were calculated to identify substrate residues with high binding efficiency at their respective positions, revealing Val (P3), Ala (P1′); and Gly and Ala (P2′ and P3′) as leading efficient binders. Binding efficiencies were lowered by molecular weight. Substrate recognition was assessed by mapping of binding subsites, and Mpro specificity was evaluated through the resolution of intermolecular interaction at the binding interface. Molecular dynamics simulations for 20 ns were performed to assess the stability and behaviour of 132 Mpro systems complexed with KLQ*** substrates. Principal component analysis (PCA), was performed to assess II protein motions and conformational changes during the simulations. A strategy was formulated to classify and evaluate relations in the Mpro PCA motions, revealing four main clades of similarity. Similarity within a clade (Group 2) and dissimilarity between clades were confirmed. Trajectory visualisation revealed complex stability, substrate unbinding and dimer dissociation for various Mpro systems. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Zabo, Sophakama
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365566 , vital:65760
- Description: COVID-19, as a disease resulting from SARS-CoV-2 infection, and a pandemic has had a devastating effect on the world. There are limited effective measures that control the spread and treatment of COVID-19 illness. The homodimeric cysteine main protease (Mpro) is crucial to the life cycle of the virus, as it cleaves the large polyproteins 1a and 1ab into matured, functional non-structural proteins. The Mpro exhibits high degrees of conservation in sequence, structure and specificity across coronavirus species, making it an ideal drug target. The Mpro substrate-binding profiles remain, despite the resolution of its recognition sequence and cleavage points (Leu-Gln↓(Ser/Ala/Gly)). In this study, a series of hexapeptide sequences containing the appropriate recognition sequence and cleavage points were generated and screened against the Mpro to study these binding profiles, and to further be the basis for efficiency-driven drug design. A multi-conformer hexapeptide substrate library comprising optimised 81000 models of 810 unique sequences was generated using RDKit within the context of python. Terminal capping with ACE and NMe was effected using SMILES and SMARTS matching. Multiple hexapeptides were complexed with chain B of crystallographic Mpro (PDS ID: 6XHM), following the validation of chain B for this purpose using AutoDock Vina at high levels of exhaustiveness (480). The resulting Vina scores ranged between -8.7 and -7.0 kcal.mol-1, and the reproducibility of best poses was validated through redocking. Ligand efficiency indices were calculated to identify substrate residues with high binding efficiency at their respective positions, revealing Val (P3), Ala (P1′); and Gly and Ala (P2′ and P3′) as leading efficient binders. Binding efficiencies were lowered by molecular weight. Substrate recognition was assessed by mapping of binding subsites, and Mpro specificity was evaluated through the resolution of intermolecular interaction at the binding interface. Molecular dynamics simulations for 20 ns were performed to assess the stability and behaviour of 132 Mpro systems complexed with KLQ*** substrates. Principal component analysis (PCA), was performed to assess II protein motions and conformational changes during the simulations. A strategy was formulated to classify and evaluate relations in the Mpro PCA motions, revealing four main clades of similarity. Similarity within a clade (Group 2) and dissimilarity between clades were confirmed. Trajectory visualisation revealed complex stability, substrate unbinding and dimer dissociation for various Mpro systems. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Racism against Black soccer players in the English Premier League
- Authors: Zinyemba, Douglas Takudzwa
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425300 , vital:72227
- Description: This study analyses racism against black players in the English Premier League. To that end, this thesis studies online articles published between 2018 and 2021 by two British tabloids, namely, The Daily Mail and The Sun, to make sense of the various ways in which black soccer players experience racism. This thesis uses the theoretical concept of “racial xenophobia” to analyse and understand expressions of antipathy towards black players playing in the Premier League. A key finding in the thesis suggests that fans and players racially abuse black players in the stadiums by liking them to animals and treating them as sub-human. Another finding in the study is that fans use the bad performances of black players as an excuse to racially abuse them via social media platforms. Social media in the 21st century has now accelerated the rate at which racism is perpetrated as fans now have more access to players through their accounts. The study also found that tabloids do not only report about racist abuse but are also guilty of portraying black players in racially stereotypical ways. This research concludes that racism against black players remains a constant feature of football in the English Premier League from the time black players started to feature in the sport in the 1970s. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Zinyemba, Douglas Takudzwa
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425300 , vital:72227
- Description: This study analyses racism against black players in the English Premier League. To that end, this thesis studies online articles published between 2018 and 2021 by two British tabloids, namely, The Daily Mail and The Sun, to make sense of the various ways in which black soccer players experience racism. This thesis uses the theoretical concept of “racial xenophobia” to analyse and understand expressions of antipathy towards black players playing in the Premier League. A key finding in the thesis suggests that fans and players racially abuse black players in the stadiums by liking them to animals and treating them as sub-human. Another finding in the study is that fans use the bad performances of black players as an excuse to racially abuse them via social media platforms. Social media in the 21st century has now accelerated the rate at which racism is perpetrated as fans now have more access to players through their accounts. The study also found that tabloids do not only report about racist abuse but are also guilty of portraying black players in racially stereotypical ways. This research concludes that racism against black players remains a constant feature of football in the English Premier League from the time black players started to feature in the sport in the 1970s. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
Leveraging LTSP to deploy a sustainable e-infrastructure for poor communities in South Africa
- Authors: Zvidzayi, Tichaona Manyara
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365577 , vital:65761
- Description: Poverty alleviation is one of the main challenges the South African government is facing. Information and knowledge are key strategic resources for both social and economic development, and nowadays they most often rely on Information and Communication Technologies (ICTs). Poor communities have limited or no access to functioning e-infrastructure, which underpins ICT. The Siyakhula Living Lab (SLL) is a joint project between the universities of Rhodes and Fort Hare that has been running for over 15 years now. The SLL solution is currently implemented in schools in the Eastern Cape’s Dwesa-Mbhashe municipality as well as schools in Makhanda (formerly Grahamstown). Over the years, a number of blueprints for the meaningful connection of poor communities was developed. The research reported in this thesis sought to review and improve the Siyakhula Living Lab (SLL) blueprint regarding fixed computing infrastructure (as opposed to networking and applications). The review confirmed the viability of the GNU/Linux Terminal Server Project (LTSP) based computing infrastructure deployed in schools to serve the surrounding community. In 2019 LTSP was redesigned and rewritten to improve on the previous version. Amongst other improvements, LTSP19+ has a smaller memory footprint and supports a graphical way to prepare and maintain the client’s image using virtual machines. These improvements increase the potential life of ICT projects implementing the SLL solution, increasing the participation of members of the community (especially teachers) to the maintenance of the computing installations. The review recommends the switching from thin clients deployments to full ("thick") clients deployments, still booting from the network and mounting their file systems on a central server. The switch is motivated by reasons that go from cost-effectiveness to the ability to survive the sudden unavailability of the central server. From experience in the previous deployment, electrical power surge protection should be mandatory. Also, UPS to protect the file system of the central server should be configured to start the shutdown immediately on electrical power loss in order to protect the life of the UPS battery (and make it possible to use cheaper UPS that report only on network power loss). The research study contributed to one real-life computing infrastructure deployment in the Ntsika school in Makhanda and one re-deployment in the Ngwane school in the Dwesa-Mbhashe area. For about two years, the research also supported continuous maintenance for the Ntsika, Ngwane and Mpume schools. , Thesis (MSc) -- Faculty of Science, Computer Science, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Zvidzayi, Tichaona Manyara
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365577 , vital:65761
- Description: Poverty alleviation is one of the main challenges the South African government is facing. Information and knowledge are key strategic resources for both social and economic development, and nowadays they most often rely on Information and Communication Technologies (ICTs). Poor communities have limited or no access to functioning e-infrastructure, which underpins ICT. The Siyakhula Living Lab (SLL) is a joint project between the universities of Rhodes and Fort Hare that has been running for over 15 years now. The SLL solution is currently implemented in schools in the Eastern Cape’s Dwesa-Mbhashe municipality as well as schools in Makhanda (formerly Grahamstown). Over the years, a number of blueprints for the meaningful connection of poor communities was developed. The research reported in this thesis sought to review and improve the Siyakhula Living Lab (SLL) blueprint regarding fixed computing infrastructure (as opposed to networking and applications). The review confirmed the viability of the GNU/Linux Terminal Server Project (LTSP) based computing infrastructure deployed in schools to serve the surrounding community. In 2019 LTSP was redesigned and rewritten to improve on the previous version. Amongst other improvements, LTSP19+ has a smaller memory footprint and supports a graphical way to prepare and maintain the client’s image using virtual machines. These improvements increase the potential life of ICT projects implementing the SLL solution, increasing the participation of members of the community (especially teachers) to the maintenance of the computing installations. The review recommends the switching from thin clients deployments to full ("thick") clients deployments, still booting from the network and mounting their file systems on a central server. The switch is motivated by reasons that go from cost-effectiveness to the ability to survive the sudden unavailability of the central server. From experience in the previous deployment, electrical power surge protection should be mandatory. Also, UPS to protect the file system of the central server should be configured to start the shutdown immediately on electrical power loss in order to protect the life of the UPS battery (and make it possible to use cheaper UPS that report only on network power loss). The research study contributed to one real-life computing infrastructure deployment in the Ntsika school in Makhanda and one re-deployment in the Ngwane school in the Dwesa-Mbhashe area. For about two years, the research also supported continuous maintenance for the Ntsika, Ngwane and Mpume schools. , Thesis (MSc) -- Faculty of Science, Computer Science, 2022
- Full Text:
- Date Issued: 2022-10-14