Exploration of remote work and wellbeing of academics in a South African tertiary institution
- Authors: Chikutu, Michelle
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405963 , vital:70223
- Description: Thesis embargoed. To be released in 2024. , Thesis (MA) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Chikutu, Michelle
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405963 , vital:70223
- Description: Thesis embargoed. To be released in 2024. , Thesis (MA) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-10-14
Exploring the political economy of the broadcast and distribution of the Mzansi Super League in South Africa
- Authors: Pettitt, Stephen John
- Date: 2021-10-29
- Subjects: Cricket Political aspects South Africa , Discrimination in sports South Africa , South Africa Social conditions , South Africa Economic conditions , Broadcasting South Africa , Cricket South Africa (Organization) , Television broadcasting of sports , Free-to-air broadcasting (FTA) South Africa , Mzansi Super League
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192308 , vital:45215
- Description: This thesis is a critical political economy analysis of the role played by the broadcast and distribution of the Mzansi Super League (MSL), a T20 cricket tournament in South Africa, in the transformation project of Cricket South Africa (CSA). The case study methodology is based on the four-leaf clover framework developed by Ruth Teer-Tomaselli. Cricket in South Africa is often viewed as a white and middle-class dominated sport, and CSA has been mandated to redress the historical racially segregated sport through a transformation agenda that focuses on changing the demographics of cricket. This paper investigates how the broadcast of a cricket tournament like the MSL on a Public Service Broadcaster (PSB) can have a positive effect on transformation due to the increased access and wider distribution. The broadcast regulations acknowledge this, as is seen in the introduction of ICASA draft regulations seeking to make more sport available on PSBs. The South African sports broadcast landscape is dominated by MultiChoice’s SuperSport, which has acquired a monopoly on sports broadcasting. The South African Broadcast Corporation (SABC) cannot compete, given its financial difficulties. A fall-out between CSA and SuperSport meant the SABC broadcast the MSL tournament, which lost CSA revenue but gained it a bigger audience. This thesis uses lived experiences and examples to illustrate that despite a financial loss, the wider media distribution of cricket will have positive effects on transformation that could counter the financial loss, especially if CSA creates new streams of income so that it relies less on broadcast revenue. In the current climate, however, compounded by internal financial and management issues, CSA cannot afford to forego the revenue from a private broadcaster and thus has no choice but to pursue a deal with a private broadcaster and lose out on the potential benefits of a wider audience. , Thesis (MA) -- Faculty of Humanities, Journalism and Media Studies, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Pettitt, Stephen John
- Date: 2021-10-29
- Subjects: Cricket Political aspects South Africa , Discrimination in sports South Africa , South Africa Social conditions , South Africa Economic conditions , Broadcasting South Africa , Cricket South Africa (Organization) , Television broadcasting of sports , Free-to-air broadcasting (FTA) South Africa , Mzansi Super League
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192308 , vital:45215
- Description: This thesis is a critical political economy analysis of the role played by the broadcast and distribution of the Mzansi Super League (MSL), a T20 cricket tournament in South Africa, in the transformation project of Cricket South Africa (CSA). The case study methodology is based on the four-leaf clover framework developed by Ruth Teer-Tomaselli. Cricket in South Africa is often viewed as a white and middle-class dominated sport, and CSA has been mandated to redress the historical racially segregated sport through a transformation agenda that focuses on changing the demographics of cricket. This paper investigates how the broadcast of a cricket tournament like the MSL on a Public Service Broadcaster (PSB) can have a positive effect on transformation due to the increased access and wider distribution. The broadcast regulations acknowledge this, as is seen in the introduction of ICASA draft regulations seeking to make more sport available on PSBs. The South African sports broadcast landscape is dominated by MultiChoice’s SuperSport, which has acquired a monopoly on sports broadcasting. The South African Broadcast Corporation (SABC) cannot compete, given its financial difficulties. A fall-out between CSA and SuperSport meant the SABC broadcast the MSL tournament, which lost CSA revenue but gained it a bigger audience. This thesis uses lived experiences and examples to illustrate that despite a financial loss, the wider media distribution of cricket will have positive effects on transformation that could counter the financial loss, especially if CSA creates new streams of income so that it relies less on broadcast revenue. In the current climate, however, compounded by internal financial and management issues, CSA cannot afford to forego the revenue from a private broadcaster and thus has no choice but to pursue a deal with a private broadcaster and lose out on the potential benefits of a wider audience. , Thesis (MA) -- Faculty of Humanities, Journalism and Media Studies, 2021
- Full Text:
- Date Issued: 2021-10-29
The impact of the BBB-EE policy instrument on wealth inequality : A case study on the banking sector of South Africa
- Moshikaro, Kei Kgaogelo Felia
- Authors: Moshikaro, Kei Kgaogelo Felia
- Date: 2021-10
- Subjects: Black Economic Empowerment (Program : South Africa) , Income distribution South Africa , South Africa Economic policy , South Africa Economic conditions 1991- , Banks and banking South Africa , South Africa. Financial Sector Regulation Act, 2017
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191035 , vital:45052
- Description: It has been recognised that, whether measured in terms of income or wealth, South Africa remains as one of the most unequal societies in the world. Reducing these high levels of inequalities has been an important area of focus through the formulation of policy instruments by South African policy makers. Within a specific focus on the South African banking sector, the objective of this research is to ascertaining the extent to which addressing inequalities was in fact achieved through the changing of wealth ownerships under the Broad Based Black Economic Empowerment policy instrument. To contextualise, the thesis surveys literature on two stylised economic hypotheses on both income and wealth to understand the potential causes of their respective inequalities. An exploration of both income, wealth measurements and their distributions in South Africa are presented, in addition to policy instruments designed to ameliorate income and wealth inequalities in South Africa. The thesis further presents brief case studies from the literature on Brazil’s success in reducing its high income inequality and the Malaysian National Economic Policy empowerment program to effect wealth economic transformation, as comparatives to the South African experience. The thesis findings indicate that contrary to the objectives of the BBB-EE instrument and wealth transfers, the program within the banking sector resulted in highly unequal wealth shares and equally high concentration levels. The richest top one per cent of individuals participating in the BEE transactions in the banking sector captured 79 per cent of the total wealth transfers, this providing indications of extremely high concentrations of wealth. Further, wealth meaningfully cumulates at only the 50 percentage level of the wealth distribution, this additionally suggesting that wealth transfers featured less in the bottom half of the wealth distribution. The banking BBB-EE wealth Gini coefficient of 0.88 is evidence of the extremely high levels of inequality that resulted from the BBB-EE program within the banking sector. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Moshikaro, Kei Kgaogelo Felia
- Date: 2021-10
- Subjects: Black Economic Empowerment (Program : South Africa) , Income distribution South Africa , South Africa Economic policy , South Africa Economic conditions 1991- , Banks and banking South Africa , South Africa. Financial Sector Regulation Act, 2017
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191035 , vital:45052
- Description: It has been recognised that, whether measured in terms of income or wealth, South Africa remains as one of the most unequal societies in the world. Reducing these high levels of inequalities has been an important area of focus through the formulation of policy instruments by South African policy makers. Within a specific focus on the South African banking sector, the objective of this research is to ascertaining the extent to which addressing inequalities was in fact achieved through the changing of wealth ownerships under the Broad Based Black Economic Empowerment policy instrument. To contextualise, the thesis surveys literature on two stylised economic hypotheses on both income and wealth to understand the potential causes of their respective inequalities. An exploration of both income, wealth measurements and their distributions in South Africa are presented, in addition to policy instruments designed to ameliorate income and wealth inequalities in South Africa. The thesis further presents brief case studies from the literature on Brazil’s success in reducing its high income inequality and the Malaysian National Economic Policy empowerment program to effect wealth economic transformation, as comparatives to the South African experience. The thesis findings indicate that contrary to the objectives of the BBB-EE instrument and wealth transfers, the program within the banking sector resulted in highly unequal wealth shares and equally high concentration levels. The richest top one per cent of individuals participating in the BEE transactions in the banking sector captured 79 per cent of the total wealth transfers, this providing indications of extremely high concentrations of wealth. Further, wealth meaningfully cumulates at only the 50 percentage level of the wealth distribution, this additionally suggesting that wealth transfers featured less in the bottom half of the wealth distribution. The banking BBB-EE wealth Gini coefficient of 0.88 is evidence of the extremely high levels of inequality that resulted from the BBB-EE program within the banking sector. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2021
- Full Text:
- Date Issued: 2021-10
A novel o/w microemulsion fixed dose combination of efavirenz, emtricitabine and tenofovir disoproxil fumarate: development and characterisation
- Authors: Mabvira, Samantha
- Date: 2022-04-06
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232925 , vital:50038
- Description: Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Mabvira, Samantha
- Date: 2022-04-06
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232925 , vital:50038
- Description: Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2022
- Full Text:
- Date Issued: 2022-04-06
Analysis of corporate failures: a case study of two South African banks
- Mqomboti, Xitshembiso Pronacia
- Authors: Mqomboti, Xitshembiso Pronacia
- Date: 2023-02
- Subjects: Business failures South Africa , Corporate governance South Africa , Risk management , Operational risk , Business ethics , Bank management South Africa , Banks and banking South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419151 , vital:71620
- Description: This study analysed the factors that contributed to the failure of Venda Building Society Mutual Bank (VBS) and African Bank Limited and the impact it had on their key stakeholders. The specific objectives of this study were to evaluate African Bank and VBS bank's operational risk management processes and controls, the role of ethical failures at VBS bank and African Bank; and assess how the failures affected their stakeholders. The population sample of the study included African Bank and VBS. The study adopted a qualitative research method. Existing reports from both African Bank and VBS were used to collect data. The study adopted a thematic data analysis method, which includes data coding and the development of themes. The data analysis framework was derived from a defined set of research propositions and seven (7) themes were derived from this analysis method. The failure in operational controls of both banks and ineffective risk management structures including unethical conduct by the executive management and board of VBS bank, irregular financial transactions and weakened external auditing function resulted in an unaccountable executive relationship and reckless lending decision-making. This research study will expand on the existing body of knowledge on the failures and near-failures of banks in the South African banking sector. The South African banking industry and its regulatory bodies will be better equipped to strengthen their corporate governance in risk controls to mitigate future collapses and near collapses of banks. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
- Date Issued: 2023-02
- Authors: Mqomboti, Xitshembiso Pronacia
- Date: 2023-02
- Subjects: Business failures South Africa , Corporate governance South Africa , Risk management , Operational risk , Business ethics , Bank management South Africa , Banks and banking South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419151 , vital:71620
- Description: This study analysed the factors that contributed to the failure of Venda Building Society Mutual Bank (VBS) and African Bank Limited and the impact it had on their key stakeholders. The specific objectives of this study were to evaluate African Bank and VBS bank's operational risk management processes and controls, the role of ethical failures at VBS bank and African Bank; and assess how the failures affected their stakeholders. The population sample of the study included African Bank and VBS. The study adopted a qualitative research method. Existing reports from both African Bank and VBS were used to collect data. The study adopted a thematic data analysis method, which includes data coding and the development of themes. The data analysis framework was derived from a defined set of research propositions and seven (7) themes were derived from this analysis method. The failure in operational controls of both banks and ineffective risk management structures including unethical conduct by the executive management and board of VBS bank, irregular financial transactions and weakened external auditing function resulted in an unaccountable executive relationship and reckless lending decision-making. This research study will expand on the existing body of knowledge on the failures and near-failures of banks in the South African banking sector. The South African banking industry and its regulatory bodies will be better equipped to strengthen their corporate governance in risk controls to mitigate future collapses and near collapses of banks. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
- Date Issued: 2023-02
The biology and movement patterns of non-native common carp, cyprinus carpio (l) in Groenvlei, South Africa
- Authors: Mukhari, Dinah Lorraine
- Date: 2022-04-06
- Subjects: Carp South Africa Goukamma Nature Reserve , Introduced fishes South Africa Goukamma Nature Reserve , Carp Behavior South Africa Goukamma Nature Reserve , Carp South Africa Goukamma Nature Reserve Growth , Carp Habitat South Africa Goukamma Nature Reserve , Carp South Africa Goukamma Nature Reserve Reproduction , Habitat conservation South Africa Goukamma Nature Reserve , Aquatic resources conservation South Africa Goukamma Nature Reserve
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291233 , vital:56834
- Description: The common carp, Cyprinus carpio is a highly invasive fish species, first introduced into South Africa in the late nineteen century, and now widely spread throughout the country. In 1991 carp were illegally introduced to Groenvlei, within the Goukamma Nature Reserve in the Western Cape Province. Decreases in water quality and declines in biota have been attributed to the now large numbers of carp. Management measures have commenced to reduce the carp population, however these are not underpinned by science as little is known about the biology and movement patterns of resident carp. The age, growth and maturity of carp within the lake was determined using oxytetracycline hydrochloride marked asteriscus otoliths and macroscopic gonad development staging methods. The results showed that carp in Groenvlei had similar growth characteristics to the invasive populations in North America and Australia; fast growth during the first three to five years and reproductive maturity attained between the ages of two to three years, and are long lived (maximum age of 20 years old). Their growth however differed from the only other study on a South African population. Six acoustically tagged carp were manually tracked in order to report on their movement patterns and habitat use. Carp moved much greater distances in February compared to October and November, and occupied different areas of the lake. In November they were found to aggregate in backwaters which corresponds with their breeding activities. Literature on global carp control shows that whilst eradication of this fish can be achieved in small isolated waters using icthyocides and water drawdowns, in conservation priority areas such as Groenvlei where this is not possible, mechanical removal using multiple gears targeting vulnerable life stages can most efficient at controlling carp. This study identified where and when these methods could be focused to optimise control efforts. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Mukhari, Dinah Lorraine
- Date: 2022-04-06
- Subjects: Carp South Africa Goukamma Nature Reserve , Introduced fishes South Africa Goukamma Nature Reserve , Carp Behavior South Africa Goukamma Nature Reserve , Carp South Africa Goukamma Nature Reserve Growth , Carp Habitat South Africa Goukamma Nature Reserve , Carp South Africa Goukamma Nature Reserve Reproduction , Habitat conservation South Africa Goukamma Nature Reserve , Aquatic resources conservation South Africa Goukamma Nature Reserve
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291233 , vital:56834
- Description: The common carp, Cyprinus carpio is a highly invasive fish species, first introduced into South Africa in the late nineteen century, and now widely spread throughout the country. In 1991 carp were illegally introduced to Groenvlei, within the Goukamma Nature Reserve in the Western Cape Province. Decreases in water quality and declines in biota have been attributed to the now large numbers of carp. Management measures have commenced to reduce the carp population, however these are not underpinned by science as little is known about the biology and movement patterns of resident carp. The age, growth and maturity of carp within the lake was determined using oxytetracycline hydrochloride marked asteriscus otoliths and macroscopic gonad development staging methods. The results showed that carp in Groenvlei had similar growth characteristics to the invasive populations in North America and Australia; fast growth during the first three to five years and reproductive maturity attained between the ages of two to three years, and are long lived (maximum age of 20 years old). Their growth however differed from the only other study on a South African population. Six acoustically tagged carp were manually tracked in order to report on their movement patterns and habitat use. Carp moved much greater distances in February compared to October and November, and occupied different areas of the lake. In November they were found to aggregate in backwaters which corresponds with their breeding activities. Literature on global carp control shows that whilst eradication of this fish can be achieved in small isolated waters using icthyocides and water drawdowns, in conservation priority areas such as Groenvlei where this is not possible, mechanical removal using multiple gears targeting vulnerable life stages can most efficient at controlling carp. This study identified where and when these methods could be focused to optimise control efforts. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04-06
Recruitment disruptors: an exploratory study on the perception of artificial intelligence amongst selected Eastern Cape Province recruiters
- Authors: Sobekwa, Sinazo
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232238 , vital:49974
- Description: Thesis (MA) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Sobekwa, Sinazo
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232238 , vital:49974
- Description: Thesis (MA) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-04
A case study of role conflict experienced by middle management during organizational change
- Authors: Sepeng, Mugabe
- Date: 2023-10-13
- Subjects: Role conflict , Change management , Middle managers , Middle management , ISO 9001 Standard Implementation of
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419189 , vital:71624
- Description: This research investigation is based on continuous improvement changes arising from - and related to - ISO 9001 implementation at Sundays River Citrus Company (SRCC), which is one of the biggest packers, marketers, and exporters of citrus fruit in South Africa. The Board of SRCC adopted ISO 9001 to ensure organizational efficiency and sustainability while improving quality control, customer service, teamwork and leadership. However, research indicates not all organizations that have Implemented ISO 9001 realize the intended benefits. While no research was available on the citrus agriculture industry, research in the tourism industry indicates that not only did some companies not realize the expected benefits, but also incurred substantial investment costs. It is estimated that approximately thirty to ninety percent of change initiatives fail to meet their objectives, and research studies also indicate that middle managers play a critical role that can influence the outcomes of a change project. However, Balogun (2003) indicates that middle managers play a complex role and are exposed to role conflict, which can influence the outcomes of change initiatives. In this context, this research study aimed to investigate the role conflicts experienced by middle managers during the process of an ISO 9001 continuous improvement change. The study draws on role theory, applying it to their management of change. The following role conflict types were investigated: (1) intra-sender conflict, (2) inter-sender role conflict, (3) inter-role conflict, (4) role ambiguity and (5) role strain. The research approach is qualitative, and has adopted a post-positivist paradigm, utilizing a deductive qualitative method. The study adopted a case study approach. Data was gathered mainly from interviews and supported by organizational documents. Semi structured interviews were conducted with questions formulated through the use of the coding manual (See Appendix C) to ensure alignment of data collection with the research propositions derived from literature. A deductive thematic analysis method was used to analyze the interview data. The research findings confirmed that during continuous improvement change, as middle managers strived to satisfy the incompatible expectations of role senders (mainly senior and junior managers), they experienced the five role conflict types. The study findings also indicate that middle managers experience conflicts due to the incompatible expectations of other role senders such as quality and marketing departments. The findings suggest that middle managers are managing these conflicts, but notes that they do require some assistance and support from senior management. The study concludes with managerial and research recommendations. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Sepeng, Mugabe
- Date: 2023-10-13
- Subjects: Role conflict , Change management , Middle managers , Middle management , ISO 9001 Standard Implementation of
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419189 , vital:71624
- Description: This research investigation is based on continuous improvement changes arising from - and related to - ISO 9001 implementation at Sundays River Citrus Company (SRCC), which is one of the biggest packers, marketers, and exporters of citrus fruit in South Africa. The Board of SRCC adopted ISO 9001 to ensure organizational efficiency and sustainability while improving quality control, customer service, teamwork and leadership. However, research indicates not all organizations that have Implemented ISO 9001 realize the intended benefits. While no research was available on the citrus agriculture industry, research in the tourism industry indicates that not only did some companies not realize the expected benefits, but also incurred substantial investment costs. It is estimated that approximately thirty to ninety percent of change initiatives fail to meet their objectives, and research studies also indicate that middle managers play a critical role that can influence the outcomes of a change project. However, Balogun (2003) indicates that middle managers play a complex role and are exposed to role conflict, which can influence the outcomes of change initiatives. In this context, this research study aimed to investigate the role conflicts experienced by middle managers during the process of an ISO 9001 continuous improvement change. The study draws on role theory, applying it to their management of change. The following role conflict types were investigated: (1) intra-sender conflict, (2) inter-sender role conflict, (3) inter-role conflict, (4) role ambiguity and (5) role strain. The research approach is qualitative, and has adopted a post-positivist paradigm, utilizing a deductive qualitative method. The study adopted a case study approach. Data was gathered mainly from interviews and supported by organizational documents. Semi structured interviews were conducted with questions formulated through the use of the coding manual (See Appendix C) to ensure alignment of data collection with the research propositions derived from literature. A deductive thematic analysis method was used to analyze the interview data. The research findings confirmed that during continuous improvement change, as middle managers strived to satisfy the incompatible expectations of role senders (mainly senior and junior managers), they experienced the five role conflict types. The study findings also indicate that middle managers experience conflicts due to the incompatible expectations of other role senders such as quality and marketing departments. The findings suggest that middle managers are managing these conflicts, but notes that they do require some assistance and support from senior management. The study concludes with managerial and research recommendations. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
- Date Issued: 2023-10-13
The depositional history and evaluation of two late quaternary, diamondiferous pocket beaches, south-western Namibia
- Authors: Milad, Micael George
- Date: 2004-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/420934 , vital:71795
- Description: The two Late Quaternary, diamondiferous pocket beach deposits studied here are situated along a 10 km stretch of the storm-dominated, Atlantic coastline of the Sperrgebiet, south-western Namibia. The pocket beaches are approximately 130 km north of the Orange River mouth, which is widely accepted as a long-lived point source for diamonds sourced from the interior of southern Africa. A total of fourteen pocket beach deposits were recently evaluated in this area, but only two of these, namely Site 2 (to the south) and Site 3 (to the north), are considered here. The main diamondbearing horizons are beach gravels, which occur within, and form part of, the pocket beach sequences. The beach gravels are mostly blanketed by sand overburden, meaning that exposures available for study were limited, and much reliance was placed on borehole logging and observations of evaluation sample tailings. The main aims are to unravel the depositional history of the pocket beach sequences, identify the controls on diamond mineralisation in the beach gravels, and critically examine two different methods of estimating average diamond size for the deposits. In pursuit of these aims, sedimentological characteristics of the unconsolidated pocket beach deposits were recorded using small diameter drill holes, hydraulic grab bulk samples, trench exposures and surface outcrops. The surface geology, geomorphology and modern wave patterns were mapped using high-resolution, Airborne Laser Survey imagery coupled with extensive field checking. Three-dimensional geological modeling software was used to gain insight into the subsurface morphology of the deposits. Fossil shell samples were used to aid interpretation of ancient depositional environments and to date parts of the pocket beach sequences. Variations in diamond concentration and the size of diamonds were recorded using bulk samples, some of which were taken from a trench, but most of which were excavated using a hydraulic grab tool called the GB50. Finally, by using diamond size data from Site 3, sample data from diamondiferous beach gravels to the south of the study area and sample campaign simulations, two alternative methods of evaluating average diamond size in marine gravel deposits were appraised.The pocket beach sequences occur within north-south trending valleys of a major deflation basin and are separated from one another by rocky headlands. The ridge-and-valley topography of the deflation basin has resulted from differential erosion of Late Proterozoic basement rock units, alternating layers of which differ greatly in their resistance to the long-lived, local denudationalprocesses. On the basis of the stratigraphic information collected from the unconsolidated pocket beach valley fills, interpreted within the context of global, Late Pleistocene sea level records, the following depositional history is deduced : a) Deposition of sheetflood gravels by ephemeral streams, activated during a regressive phase. b) Transgression, culminating in the deposition of a gravel beach, representing a sea level highstand of +4 metres above mean sea level (mamsl) at between 120 000 and 130 000 BP. c)A regressive phase, resulting in deflation of former valley fills to the bedrock valley floor and accompanied by re-activation of ephemeral stream activity to form sheetflood deposits; this represents a protracted period of subaerial exposure of the +4 m gravel beach deposit. d) Deposition of a great volume of sediment in the valleys during the latter stages of the transgression from the Last Glacial Maximum (LGM). The sequence generated during this phase, which started at ca. 9 000 BP, contains : i) pan/coastal sabkha sediments, ii) shallow, sheltered bay sediments, iii) back-barrier lagoonal sediments, iv) a gravel beach deposit representing a sea level stillstand at -5 mamsl, laid down between 7 600 and 5 600 BP, v) another gravel beach deposit representing the well-known Middle Holocene sea level highstand at +2 to +3 mamsl, laid down at ca. 5 000 BP, and which terminated the transgression from the LGM. e) A minor regression to the current sea level, accompanied by progradation of the shoreline to its current position. This progradational marine unit consists almost entirely of sand and grit, reflecting the lack of gravel supply to this part of the coastline in the most recent past. f) Deposition of modern coastal dunes, which cap the pocket beach sequence and are the youngest sediments in the study area. Using trench and hydraulic grab evaluation sample results, in combination with analysis of wave patterns and field observations, the following local controls on the density distribution (ie. concentration) and size distribution of diamonds in the gravel beach deposits (+4, -5 and +2 to +3 mamsl stands) are recognised: a) Gravel beach depositional processes, which are responsible for clast sorting on the beach, have influenced the density and size distribution of diamonds. The infill zone, or beach toe, favours maximum diamond concentration while diamond size decreases from the imbricate zone (intertidal) to the infill zone (subtidal). b) Wave energy is identified as the dominant local control on diamond size distribution, but has also influenced diamond concentration to a limited degree. Larger diamonds are intimately associated with coarser beach gravels, both of which are a reflection of increased wave energy. Higher concentrations of diamonds are sometimes associated with zones of coarser gravel and therefore greater wave energy. c) The time of deposition of the host gravel beach is seen to be the dominant controlling factor with respect to diamond concentration. This is seen as evidence of significant temporal variation in the availability of diamonds in the littoral evironment. A significant reduction (20%) in average diamond size from Site 2 to Site 3, over a distance of only 6 km, is evident. The following were identified as reasons for this reduction in diamond size : a) Longshore sorting processes, of which the long-lived northerly littoral drift is a key part, are known to have played a role in the diminution of diamond size northwards from the Orange River mouth point source. However, it is believed that this can only partly account for the observed 20% reduction in diamond size. b) Input of sediment and smaller diamonds at Site 3, reworked out of an older, Eocene-aged marine succession in the hinterland, is recognised as a possible additional reason for the large reduction in diamond size from Site 2 to Site 3. It is also speculated that the large size of the pocket beach at Site 3, relative to Site 2, may have resulted in lower average wave energy at Site 3, with consequent reduced average diamond size. Diamond size in the beach gravels of Site 3, as well as in beach gravels elsewhere in the Sperrgebiet, is seen to be lognormally-distributed within geologically homogeneous zones. In theory, lognormal mean estimators represent the best method of estimating average diamond size in such cases, whereas the arithmetic mean estimator has the tendency to overestimate when large outlier values occur. Lognormal mean estimators have the added benefit of providing for the calculation of confidence limits, which are becoming increasingly more important as financial lending institutions insist on better quantification of the risk involved in resource estimates. Sample campaign simulations demonstrate, for the kinds of diamond size-frequency distributions typical of beach gravel deposits at Site 3, that there is no significant improvement in the accuracy of average diamond size estimates when lognormal mean estimators are used instead of the arithmetic mean estimator. This is because the variance (a ) of the diamond populations is low, and large outlier values are extremely unlikely to occur. However, simulation of a diamond population with high variance, drawn from a sample of beach gravels near the Orange River mouth, shows that lognormal estimators produce significantly more accurate results when a is large. Since individual diamond weights were not recorded during evaluation sampling of Site 3, numerical solution of lognormal estimators is not possible, and these would need to be solved using a less accurate graphical method. It is therefore recommended that individual diamond weights are recorded in future sampling campaigns, allowing for the use of lognormal mean estimators, and the calculation of confidence limits for average diamond size estimates. , Thesis (MSc) -- Science, Geology, 2004
- Full Text:
- Date Issued: 2004-03
- Authors: Milad, Micael George
- Date: 2004-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/420934 , vital:71795
- Description: The two Late Quaternary, diamondiferous pocket beach deposits studied here are situated along a 10 km stretch of the storm-dominated, Atlantic coastline of the Sperrgebiet, south-western Namibia. The pocket beaches are approximately 130 km north of the Orange River mouth, which is widely accepted as a long-lived point source for diamonds sourced from the interior of southern Africa. A total of fourteen pocket beach deposits were recently evaluated in this area, but only two of these, namely Site 2 (to the south) and Site 3 (to the north), are considered here. The main diamondbearing horizons are beach gravels, which occur within, and form part of, the pocket beach sequences. The beach gravels are mostly blanketed by sand overburden, meaning that exposures available for study were limited, and much reliance was placed on borehole logging and observations of evaluation sample tailings. The main aims are to unravel the depositional history of the pocket beach sequences, identify the controls on diamond mineralisation in the beach gravels, and critically examine two different methods of estimating average diamond size for the deposits. In pursuit of these aims, sedimentological characteristics of the unconsolidated pocket beach deposits were recorded using small diameter drill holes, hydraulic grab bulk samples, trench exposures and surface outcrops. The surface geology, geomorphology and modern wave patterns were mapped using high-resolution, Airborne Laser Survey imagery coupled with extensive field checking. Three-dimensional geological modeling software was used to gain insight into the subsurface morphology of the deposits. Fossil shell samples were used to aid interpretation of ancient depositional environments and to date parts of the pocket beach sequences. Variations in diamond concentration and the size of diamonds were recorded using bulk samples, some of which were taken from a trench, but most of which were excavated using a hydraulic grab tool called the GB50. Finally, by using diamond size data from Site 3, sample data from diamondiferous beach gravels to the south of the study area and sample campaign simulations, two alternative methods of evaluating average diamond size in marine gravel deposits were appraised.The pocket beach sequences occur within north-south trending valleys of a major deflation basin and are separated from one another by rocky headlands. The ridge-and-valley topography of the deflation basin has resulted from differential erosion of Late Proterozoic basement rock units, alternating layers of which differ greatly in their resistance to the long-lived, local denudationalprocesses. On the basis of the stratigraphic information collected from the unconsolidated pocket beach valley fills, interpreted within the context of global, Late Pleistocene sea level records, the following depositional history is deduced : a) Deposition of sheetflood gravels by ephemeral streams, activated during a regressive phase. b) Transgression, culminating in the deposition of a gravel beach, representing a sea level highstand of +4 metres above mean sea level (mamsl) at between 120 000 and 130 000 BP. c)A regressive phase, resulting in deflation of former valley fills to the bedrock valley floor and accompanied by re-activation of ephemeral stream activity to form sheetflood deposits; this represents a protracted period of subaerial exposure of the +4 m gravel beach deposit. d) Deposition of a great volume of sediment in the valleys during the latter stages of the transgression from the Last Glacial Maximum (LGM). The sequence generated during this phase, which started at ca. 9 000 BP, contains : i) pan/coastal sabkha sediments, ii) shallow, sheltered bay sediments, iii) back-barrier lagoonal sediments, iv) a gravel beach deposit representing a sea level stillstand at -5 mamsl, laid down between 7 600 and 5 600 BP, v) another gravel beach deposit representing the well-known Middle Holocene sea level highstand at +2 to +3 mamsl, laid down at ca. 5 000 BP, and which terminated the transgression from the LGM. e) A minor regression to the current sea level, accompanied by progradation of the shoreline to its current position. This progradational marine unit consists almost entirely of sand and grit, reflecting the lack of gravel supply to this part of the coastline in the most recent past. f) Deposition of modern coastal dunes, which cap the pocket beach sequence and are the youngest sediments in the study area. Using trench and hydraulic grab evaluation sample results, in combination with analysis of wave patterns and field observations, the following local controls on the density distribution (ie. concentration) and size distribution of diamonds in the gravel beach deposits (+4, -5 and +2 to +3 mamsl stands) are recognised: a) Gravel beach depositional processes, which are responsible for clast sorting on the beach, have influenced the density and size distribution of diamonds. The infill zone, or beach toe, favours maximum diamond concentration while diamond size decreases from the imbricate zone (intertidal) to the infill zone (subtidal). b) Wave energy is identified as the dominant local control on diamond size distribution, but has also influenced diamond concentration to a limited degree. Larger diamonds are intimately associated with coarser beach gravels, both of which are a reflection of increased wave energy. Higher concentrations of diamonds are sometimes associated with zones of coarser gravel and therefore greater wave energy. c) The time of deposition of the host gravel beach is seen to be the dominant controlling factor with respect to diamond concentration. This is seen as evidence of significant temporal variation in the availability of diamonds in the littoral evironment. A significant reduction (20%) in average diamond size from Site 2 to Site 3, over a distance of only 6 km, is evident. The following were identified as reasons for this reduction in diamond size : a) Longshore sorting processes, of which the long-lived northerly littoral drift is a key part, are known to have played a role in the diminution of diamond size northwards from the Orange River mouth point source. However, it is believed that this can only partly account for the observed 20% reduction in diamond size. b) Input of sediment and smaller diamonds at Site 3, reworked out of an older, Eocene-aged marine succession in the hinterland, is recognised as a possible additional reason for the large reduction in diamond size from Site 2 to Site 3. It is also speculated that the large size of the pocket beach at Site 3, relative to Site 2, may have resulted in lower average wave energy at Site 3, with consequent reduced average diamond size. Diamond size in the beach gravels of Site 3, as well as in beach gravels elsewhere in the Sperrgebiet, is seen to be lognormally-distributed within geologically homogeneous zones. In theory, lognormal mean estimators represent the best method of estimating average diamond size in such cases, whereas the arithmetic mean estimator has the tendency to overestimate when large outlier values occur. Lognormal mean estimators have the added benefit of providing for the calculation of confidence limits, which are becoming increasingly more important as financial lending institutions insist on better quantification of the risk involved in resource estimates. Sample campaign simulations demonstrate, for the kinds of diamond size-frequency distributions typical of beach gravel deposits at Site 3, that there is no significant improvement in the accuracy of average diamond size estimates when lognormal mean estimators are used instead of the arithmetic mean estimator. This is because the variance (a ) of the diamond populations is low, and large outlier values are extremely unlikely to occur. However, simulation of a diamond population with high variance, drawn from a sample of beach gravels near the Orange River mouth, shows that lognormal estimators produce significantly more accurate results when a is large. Since individual diamond weights were not recorded during evaluation sampling of Site 3, numerical solution of lognormal estimators is not possible, and these would need to be solved using a less accurate graphical method. It is therefore recommended that individual diamond weights are recorded in future sampling campaigns, allowing for the use of lognormal mean estimators, and the calculation of confidence limits for average diamond size estimates. , Thesis (MSc) -- Science, Geology, 2004
- Full Text:
- Date Issued: 2004-03
An investigation into water and sanitation in the Eastern Cape Province and potential for implementation of biotechnology platforms
- Authors: Gumunyu, Wilbert
- Date: 2022-10-14
- Subjects: Sewage South Africa Eastern Cape , Sanitation South Africa Eastern Cape , Algae Biotechnology , Biotechnology , Sewage Purification Biological treatment , Algal biofuels
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362830 , vital:65366
- Description: In contemporary South Africa, a country in transition, destruction rather than reconstruction seems commonplace. Electricity supply is at an all-time low and ‘load shedding’ is an almost daily occurrence. Similarly, more fragility of water delivery and sanitation service is being reported with the likelihood of ‘water shedding’ a soon-to-be reality. In view of the ever-increasing reported mismanagement of South Africa’s water and sanitation infrastructure, which is likely nearing the point of collapse if not already collapsed, this thesis set out to interrogate at a provincial and municipal level the status of water and sanitation in Chris Hani District Municipality (CHDM), Eastern Cape Province. One major driver behind this study was to evaluate provincial and municipal water/wastewater infrastructure as a platform to support implementation of locally developed bioprocess technologies. First, publicly available historical data was used to derive a baseline or benchmark from which to determine gains/losses in compliance, water quality and efficiency. The period 2009-2013/4 during which Blue and Green Drop reporting was routine, was used as an appropriate start point. Data thus derived indicated that, at provincial and district municipality (DM) level, potable water supply was by bulk water schemes and, sanitation was typically by waste stabilization pond (WSP) treatment of municipal sewage. The derived benchmark for the period 2009-2013/14 indicated that most plants were not compliant (~75% of the Eastern Cape Province water treatment plants (WTP) operating between average performance to critical state), operated either at- or above design capacity (Eastern Cape Province, 16%; CHDM, 19%). A large number of plants for the province (62.4%) and district (81.25%) had hydraulic design capacity or average daily flows that were unknown (information not provided in available literature or plant reports) and final effluent did not always meet the general standard (70.3% of the CHDM wastewater treatment works (WWTW)). To determine the contemporary state (2020 - 2022) of water and sanitation within CHDM, a scoping exercise of WTP and WWTW in selected local municipalities was carried out. This was done along a west-east transect by appraising WTP and WWTW in the towns of Cradock, Tarkastad, Komani, Tsomo, Cacadu, and Ngcobo. Furthermore, targeted assessment of the Queenstown WTP and the Cradock WWTW was used to derive real-time data on the status of water and sanitation infrastructure. Results showed that water and sanitation services within CHDM had, in the years between 2009-2013/14 to date, deteriorated. Freshwater demand significantly exceeded capability of water supply schemes, where demand was as much as three times greater than reported available supply. For most WWTW, operation was in excess of capacity and between 1.52 and 12 times installed hydraulic loading. The targeted scoping exercise revealed that Queenstown WTP is a moderate risk plant (Cumulative risk rating, CRR = 11 and maximum risk rating, MRR = 47.8%), whereas Cradock WWTW was in working condition but with challenges and some infrastructural dysfunction. Assessment of water/effluent quality revealed that turbidity and TOC were above SANS 241 general limit. Non-compliance in terms of nitrate/nitrite-N, ammonium-N, phosphate-P, TSS, total coliforms, E. Coli, and free chlorine was evident at Cradock WWTW. Unstructured interviews with plant operators corroborated these findings. The overwhelming support for bulk schemes for potable water provision and WSP for sanitation indicated a partially water secure municipal district but derelict in terms of its sanitation services. The later, it was concluded, in particular provides an ideal opportunity for implementation of platform technologies to support bioprocesses for entrepreneurship, employment, economic benefit and to secure a closed circular economy for regional water and sanitation through valorisation of co-product streams. Among the co-product streams considered in this thesis are biomass, biogas, biofertilizers, biofuels and several high value chemical products. , Thesis (MSc) -- Faculty of Science, Institute for Environmental Biotechnology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Gumunyu, Wilbert
- Date: 2022-10-14
- Subjects: Sewage South Africa Eastern Cape , Sanitation South Africa Eastern Cape , Algae Biotechnology , Biotechnology , Sewage Purification Biological treatment , Algal biofuels
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362830 , vital:65366
- Description: In contemporary South Africa, a country in transition, destruction rather than reconstruction seems commonplace. Electricity supply is at an all-time low and ‘load shedding’ is an almost daily occurrence. Similarly, more fragility of water delivery and sanitation service is being reported with the likelihood of ‘water shedding’ a soon-to-be reality. In view of the ever-increasing reported mismanagement of South Africa’s water and sanitation infrastructure, which is likely nearing the point of collapse if not already collapsed, this thesis set out to interrogate at a provincial and municipal level the status of water and sanitation in Chris Hani District Municipality (CHDM), Eastern Cape Province. One major driver behind this study was to evaluate provincial and municipal water/wastewater infrastructure as a platform to support implementation of locally developed bioprocess technologies. First, publicly available historical data was used to derive a baseline or benchmark from which to determine gains/losses in compliance, water quality and efficiency. The period 2009-2013/4 during which Blue and Green Drop reporting was routine, was used as an appropriate start point. Data thus derived indicated that, at provincial and district municipality (DM) level, potable water supply was by bulk water schemes and, sanitation was typically by waste stabilization pond (WSP) treatment of municipal sewage. The derived benchmark for the period 2009-2013/14 indicated that most plants were not compliant (~75% of the Eastern Cape Province water treatment plants (WTP) operating between average performance to critical state), operated either at- or above design capacity (Eastern Cape Province, 16%; CHDM, 19%). A large number of plants for the province (62.4%) and district (81.25%) had hydraulic design capacity or average daily flows that were unknown (information not provided in available literature or plant reports) and final effluent did not always meet the general standard (70.3% of the CHDM wastewater treatment works (WWTW)). To determine the contemporary state (2020 - 2022) of water and sanitation within CHDM, a scoping exercise of WTP and WWTW in selected local municipalities was carried out. This was done along a west-east transect by appraising WTP and WWTW in the towns of Cradock, Tarkastad, Komani, Tsomo, Cacadu, and Ngcobo. Furthermore, targeted assessment of the Queenstown WTP and the Cradock WWTW was used to derive real-time data on the status of water and sanitation infrastructure. Results showed that water and sanitation services within CHDM had, in the years between 2009-2013/14 to date, deteriorated. Freshwater demand significantly exceeded capability of water supply schemes, where demand was as much as three times greater than reported available supply. For most WWTW, operation was in excess of capacity and between 1.52 and 12 times installed hydraulic loading. The targeted scoping exercise revealed that Queenstown WTP is a moderate risk plant (Cumulative risk rating, CRR = 11 and maximum risk rating, MRR = 47.8%), whereas Cradock WWTW was in working condition but with challenges and some infrastructural dysfunction. Assessment of water/effluent quality revealed that turbidity and TOC were above SANS 241 general limit. Non-compliance in terms of nitrate/nitrite-N, ammonium-N, phosphate-P, TSS, total coliforms, E. Coli, and free chlorine was evident at Cradock WWTW. Unstructured interviews with plant operators corroborated these findings. The overwhelming support for bulk schemes for potable water provision and WSP for sanitation indicated a partially water secure municipal district but derelict in terms of its sanitation services. The later, it was concluded, in particular provides an ideal opportunity for implementation of platform technologies to support bioprocesses for entrepreneurship, employment, economic benefit and to secure a closed circular economy for regional water and sanitation through valorisation of co-product streams. Among the co-product streams considered in this thesis are biomass, biogas, biofertilizers, biofuels and several high value chemical products. , Thesis (MSc) -- Faculty of Science, Institute for Environmental Biotechnology, 2022
- Full Text:
- Date Issued: 2022-10-14
Tetra 4-(propargyloxy)phenoxy phthalocyanines: synthesis, spectroscopic, nonlinear optical and electrocatalytic properties
- Authors: Mwanza, Daniel
- Date: 2017
- Subjects: Phthalocyanines , Nonlinear optics , Electrocatalysis , Spectrum analysis , Thermogravimetry , Phthalocyanines Spectra
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65144 , vital:28695
- Description: This study presents the synthesis, spectroscopic, photophysical and theoretical characterisation of metal-free (H2TPrOPhOPc), cobalt (CoTPrOPhOPc) and manganese (MnTPrOPhOPc) tetra 4-(4-propargyloxy) phenoxy phthalocyanines. Thermal analysis using thermogravimetric analysis (TGA) confirmed the excellent thermal stability of synthesized tetra 4-(4- propargyloxy) phenoxy phthalocyanines. The metal complexes, CoTPrOPhOPc and MnTPrOPhOPc, exhibited better thermal stability when compared to H2TPrOPhOPc. The residual percentage weight remaining was approximately 70% for CoTPrOPhOPc and MnTPrOPhOPc and 45% for H2TPrOPhOPc after 600°C, clearly confirming the stability of the metal complexes. The MTPrOPhOPcs (where M = H2, Co and Mn) complexes exhibited excellent nonlinear optical properties with strong reverse saturable absorption (RSA), especially when 560 nm excitation laser was used. Their nonlinear optical properties followed this trend: H2TPrOPhOPc > CoTPrOPhOPc > MnTPrOPhOPc. According to the trend observed, the H2TPrOPhOPc was an excellent nonlinear optical limiter when compared to the CoTPrOPhOPc and MnTPrOPhOPc. All the investigated complexes exhibited optical limiting properties comparable to the phthalocyanine complexes reported in the literature. The MTPrOPhOPc complexes were further studied for their electrocatalytic and electroanalytical properties towards the detection of hydrogen peroxide. For the electrocatalytic studies, the synthesized complexes were immobilized onto gold electrode surfaces pre-functionalized with phenylazide (Au-PAz) monolayer. Copper (I) catalyzed alkynyl-azide cycloaddition reaction was used to covalently immobilize the MTPrOPhOPcs onto the gold electrode surfaces to form Au-PAz-MTPrOPhOPc. The MTPrOPhOPcs modified gold surfaces (Au-PAz-MTPrOPhOPc) exhibited good reproducibility and stability in various electrolyte conditions. Electrochemical and surface characterisation of the functionalised gold electrode surfaces confirmed the presence of the MTPrOPhOPcs and their electroanalysis was excellent towards electrocatalytic reduction of H2O2, with the limit of detection (LoD) and limit of quantification (LoQ) in the ^M range. The electrocatalytic reduction peaks for H2O2 were observed at -0.37 V for Au-PAz-MnTPrOPhOPc and -0.31 V for Au-PAz-CoTPrOPhOPc when Ag|AgCl pseudo-reference electrode was used. The Au-PAz-MnTPrOPhOPc and Au- PAz-CoTPrOPhOPc gold electrode surfaces showed good sensitivity and reproducibility towards the electrocatalytic reduction of hydrogen peroxide in pH 7.4 phosphate buffer solution. , Thesis (MSc) -- Faculty of Science, Chemistry, 2017
- Full Text:
- Date Issued: 2017
- Authors: Mwanza, Daniel
- Date: 2017
- Subjects: Phthalocyanines , Nonlinear optics , Electrocatalysis , Spectrum analysis , Thermogravimetry , Phthalocyanines Spectra
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65144 , vital:28695
- Description: This study presents the synthesis, spectroscopic, photophysical and theoretical characterisation of metal-free (H2TPrOPhOPc), cobalt (CoTPrOPhOPc) and manganese (MnTPrOPhOPc) tetra 4-(4-propargyloxy) phenoxy phthalocyanines. Thermal analysis using thermogravimetric analysis (TGA) confirmed the excellent thermal stability of synthesized tetra 4-(4- propargyloxy) phenoxy phthalocyanines. The metal complexes, CoTPrOPhOPc and MnTPrOPhOPc, exhibited better thermal stability when compared to H2TPrOPhOPc. The residual percentage weight remaining was approximately 70% for CoTPrOPhOPc and MnTPrOPhOPc and 45% for H2TPrOPhOPc after 600°C, clearly confirming the stability of the metal complexes. The MTPrOPhOPcs (where M = H2, Co and Mn) complexes exhibited excellent nonlinear optical properties with strong reverse saturable absorption (RSA), especially when 560 nm excitation laser was used. Their nonlinear optical properties followed this trend: H2TPrOPhOPc > CoTPrOPhOPc > MnTPrOPhOPc. According to the trend observed, the H2TPrOPhOPc was an excellent nonlinear optical limiter when compared to the CoTPrOPhOPc and MnTPrOPhOPc. All the investigated complexes exhibited optical limiting properties comparable to the phthalocyanine complexes reported in the literature. The MTPrOPhOPc complexes were further studied for their electrocatalytic and electroanalytical properties towards the detection of hydrogen peroxide. For the electrocatalytic studies, the synthesized complexes were immobilized onto gold electrode surfaces pre-functionalized with phenylazide (Au-PAz) monolayer. Copper (I) catalyzed alkynyl-azide cycloaddition reaction was used to covalently immobilize the MTPrOPhOPcs onto the gold electrode surfaces to form Au-PAz-MTPrOPhOPc. The MTPrOPhOPcs modified gold surfaces (Au-PAz-MTPrOPhOPc) exhibited good reproducibility and stability in various electrolyte conditions. Electrochemical and surface characterisation of the functionalised gold electrode surfaces confirmed the presence of the MTPrOPhOPcs and their electroanalysis was excellent towards electrocatalytic reduction of H2O2, with the limit of detection (LoD) and limit of quantification (LoQ) in the ^M range. The electrocatalytic reduction peaks for H2O2 were observed at -0.37 V for Au-PAz-MnTPrOPhOPc and -0.31 V for Au-PAz-CoTPrOPhOPc when Ag|AgCl pseudo-reference electrode was used. The Au-PAz-MnTPrOPhOPc and Au- PAz-CoTPrOPhOPc gold electrode surfaces showed good sensitivity and reproducibility towards the electrocatalytic reduction of hydrogen peroxide in pH 7.4 phosphate buffer solution. , Thesis (MSc) -- Faculty of Science, Chemistry, 2017
- Full Text:
- Date Issued: 2017
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
An evaluation of the impact of the Rhodes University Master of Education in Mathematics Education Programme in Namibia from the perspectives of its graduates
- Authors: David, Johannes
- Date: 2021-10-29
- Subjects: Master of education degree Namibia , Rhodes University. Department of Education , Mathematics Study and teaching , Critical thinking , Master of education degree Evaluation , Career development Namibia , Educational change Namibia , College students Attitudes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191942 , vital:45181
- Description: Rhodes University (RU) has been offering a MEdME (Masters in Education, Mathematics Education) degree in Namibia for over 12 years without evaluating its success and impact. This study aimed to evaluate the MEdME programme’s impact on the graduates and on mathematics education in Namibia from the perspectives of its graduates. The study also evaluated the factors that enabled or limited the impact of the programme from the perspective of RU staff members. A three-phased research study was implemented to achieve this. Phase I was a MEdME theses audit to analyze what each graduate researched which then guided the sampling process. Phase II was a distribution of a questionnaire to willing MEdME graduates to elicit their views about the programme's impact. In Phase III, selected graduates were interviewed to follow up on the questionnaire. The RU academic staff members were also interviewed about the programme's design and rationale, as well as their perspectives on its impact on graduates' professional lives. The study found that graduates believed that the programme made them more critical reflexive practitioners (CRPs) who: are now self-introspective, can reflect in context and are competent researchers. This is a sign of the programme attaining its objectives of developing and growing CRPs and graduates, who have advanced in their fields, including their ability to do research. The programme also created opportunities for graduates to study further and/or publish papers. The programme further opened up opportunities for graduates’ promotion into positions of influence in the Ministry of Education where they can positively impact on mathematics education transformation in Namibia (METN). The graduates consequently noticed improvements in some areas but they also noticed room for improvement in other areas of mathematics education in Namibia. This study therefore suggests that more mathematics teachers study further, improve their research capacity and contribute more to METN. The study also suggests a national campaign to increase mathematics teachers' content knowledge. Furthermore, the programme should reintroduce coursework to address students’ subject content knowledge. RU is also advised to explore offering a Professional MEd in Namibia for students who want to focus more on improving their mathematics content knowledge. It is also proposed that Namibia establish a research bank where researchers can upload their theses for wider dissemination. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: David, Johannes
- Date: 2021-10-29
- Subjects: Master of education degree Namibia , Rhodes University. Department of Education , Mathematics Study and teaching , Critical thinking , Master of education degree Evaluation , Career development Namibia , Educational change Namibia , College students Attitudes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191942 , vital:45181
- Description: Rhodes University (RU) has been offering a MEdME (Masters in Education, Mathematics Education) degree in Namibia for over 12 years without evaluating its success and impact. This study aimed to evaluate the MEdME programme’s impact on the graduates and on mathematics education in Namibia from the perspectives of its graduates. The study also evaluated the factors that enabled or limited the impact of the programme from the perspective of RU staff members. A three-phased research study was implemented to achieve this. Phase I was a MEdME theses audit to analyze what each graduate researched which then guided the sampling process. Phase II was a distribution of a questionnaire to willing MEdME graduates to elicit their views about the programme's impact. In Phase III, selected graduates were interviewed to follow up on the questionnaire. The RU academic staff members were also interviewed about the programme's design and rationale, as well as their perspectives on its impact on graduates' professional lives. The study found that graduates believed that the programme made them more critical reflexive practitioners (CRPs) who: are now self-introspective, can reflect in context and are competent researchers. This is a sign of the programme attaining its objectives of developing and growing CRPs and graduates, who have advanced in their fields, including their ability to do research. The programme also created opportunities for graduates to study further and/or publish papers. The programme further opened up opportunities for graduates’ promotion into positions of influence in the Ministry of Education where they can positively impact on mathematics education transformation in Namibia (METN). The graduates consequently noticed improvements in some areas but they also noticed room for improvement in other areas of mathematics education in Namibia. This study therefore suggests that more mathematics teachers study further, improve their research capacity and contribute more to METN. The study also suggests a national campaign to increase mathematics teachers' content knowledge. Furthermore, the programme should reintroduce coursework to address students’ subject content knowledge. RU is also advised to explore offering a Professional MEd in Namibia for students who want to focus more on improving their mathematics content knowledge. It is also proposed that Namibia establish a research bank where researchers can upload their theses for wider dissemination. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
In silico identification of natural inhibitory compounds against the Mycobacterium tuberculosis Enzyme Pyrazinamidase using high-throughput virtual screening techniques
- Authors: Kenyon, Thomas
- Date: 2021-10-29
- Subjects: Mycobacterium tuberculosis , Pyrazinamide , Molecular dynamics , High throughput screening (Drug development) , Mutagenesis , South African Natural Compounds database (SANCDB)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192074 , vital:45193
- Description: Tuberculosis (TB) is most commonly a pulmonary infection caused by the bacterium Mycobacterium tuberculosis. With the exception of the COVID-19 pandemic, TB was the most common cause of death due to an infectious disease for a number of years up until 2020. In 2019, 10 million people fell ill with TB worldwide and 1.4 million people died (WHO, 2020a). Additionally, multidrug-resistant TB (MDR-TB) remains a public health crisis and a health security threat. A global total of 206 030 people with multidrug- or rifampicin-resistant TB (MDR/RR-TB) were reported in 2019, a 10% increase from 186 883 in 2018. South Africa is ranked among the 48 high TB burden countries, with an estimated 360 000 people falling ill in 2019, resulting in 58 000 deaths, the majority of which being among people living with HIV. Unlike HIV, however, TB is a curable disease when managed correctly with long durations of antitubercular chemotherapy. Pyrazinamide (PZA) is an important first-line tuberculosis drug unique for its activity against latent TB. PZA is a prodrug, being converted into its active form, pyrazinoic acid (POA) by the Mtb gene pncA, coding for the pyrazinamidase enzyme (PZase). TB resistance to first-line drugs such as PZA is commonly associated with mutations in the pncA/PZase enzyme. This study aimed to identify potential novel inhibitors that bind to the active site of PZase. By making use of molecular docking studies and molecular dynamics (MD) simulations, high throughput virtual screening was performed on 623 compounds from the South African Natural Compounds database (SANCDB; https://sancdb.rubi.ru.ac.za). Ligands that selectively bound to the PZase active site were identified using docking studies, followed by MD simulations to assess ligand-PZase complex stability, Finally, hit compounds identified from the first round of MD simulations were screened again against PZase structures with high confidence point mutations known to infer PZA resistance in order to identify any novel compounds which had inhibitory potential against both WT and mutant forms of the PZase enzyme. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Kenyon, Thomas
- Date: 2021-10-29
- Subjects: Mycobacterium tuberculosis , Pyrazinamide , Molecular dynamics , High throughput screening (Drug development) , Mutagenesis , South African Natural Compounds database (SANCDB)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192074 , vital:45193
- Description: Tuberculosis (TB) is most commonly a pulmonary infection caused by the bacterium Mycobacterium tuberculosis. With the exception of the COVID-19 pandemic, TB was the most common cause of death due to an infectious disease for a number of years up until 2020. In 2019, 10 million people fell ill with TB worldwide and 1.4 million people died (WHO, 2020a). Additionally, multidrug-resistant TB (MDR-TB) remains a public health crisis and a health security threat. A global total of 206 030 people with multidrug- or rifampicin-resistant TB (MDR/RR-TB) were reported in 2019, a 10% increase from 186 883 in 2018. South Africa is ranked among the 48 high TB burden countries, with an estimated 360 000 people falling ill in 2019, resulting in 58 000 deaths, the majority of which being among people living with HIV. Unlike HIV, however, TB is a curable disease when managed correctly with long durations of antitubercular chemotherapy. Pyrazinamide (PZA) is an important first-line tuberculosis drug unique for its activity against latent TB. PZA is a prodrug, being converted into its active form, pyrazinoic acid (POA) by the Mtb gene pncA, coding for the pyrazinamidase enzyme (PZase). TB resistance to first-line drugs such as PZA is commonly associated with mutations in the pncA/PZase enzyme. This study aimed to identify potential novel inhibitors that bind to the active site of PZase. By making use of molecular docking studies and molecular dynamics (MD) simulations, high throughput virtual screening was performed on 623 compounds from the South African Natural Compounds database (SANCDB; https://sancdb.rubi.ru.ac.za). Ligands that selectively bound to the PZase active site were identified using docking studies, followed by MD simulations to assess ligand-PZase complex stability, Finally, hit compounds identified from the first round of MD simulations were screened again against PZase structures with high confidence point mutations known to infer PZA resistance in order to identify any novel compounds which had inhibitory potential against both WT and mutant forms of the PZase enzyme. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-10-29
A proposed management framework for water stewardship for small business in South Africa
- Authors: Huxtable, Collette
- Date: 2022-12-12
- Subjects: Water-supply Management , Small business South Africa , Water-supply Economic aspects , Triple bottom line , Sustainable development reporting , Competitive advantage
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419090 , vital:71615
- Description: Climate change, severe weather events, population growth and, urbanisation are just a few of the leading causes contributing to the global water crisis. This global water crisis is negatively impacting the environment, and society, which includes business (large and small). Businesses are facing many water risks and challenges in their daily operations, such as water scarcity, water stress and water pollution, which are resulting in them being negatively impacted financially. For all business to overcome these risks and challenges which are negatively impacting their operations and to assist in protecting the scarce water resources left on the planet, the implementation of water stewardship practices will play a very important role. The literature has fallen short in addressing water stewardship frameworks and practices for small business. Through a sustainability lens underpinned by Natural Resource Based View Theory, this research study sets out to develop a water stewardship framework for implementation by small business to provide them with a competitive advantage. By reviewing the current literature and frameworks available to large business organisations, the insights gained allowed for a draft water stewardship framework to be developed from this literature, suitable for small business. This draft water stewardship framework for small business was used to gather further information on its suitability for small business, through an interview process. A qualitative interview process with seven small businesses in Makhanda (South Africa), allowed for data to be gathered and used to refine and adjust the draft water stewardship framework for small business. The findings from this research study show that small business do not have a global awareness of water problems and are not aware of the concept of water stewardship. Small business were very receptive to the draft water stewardship framework for small business and felt that its implementation would make a difference in saving scarce water resources and create a competitive advantage for them. The study concludes by recommending a water stewardship framework for small business (WSF4SB), who will play a leading role in fighting the water crisis. The implementation of the WSF4SB aims to provide small business with a sustainable competitive advantage by looking after scarce water resources ensuring there is sufficient water for current and future generations. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
- Date Issued: 2022-12-12
- Authors: Huxtable, Collette
- Date: 2022-12-12
- Subjects: Water-supply Management , Small business South Africa , Water-supply Economic aspects , Triple bottom line , Sustainable development reporting , Competitive advantage
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419090 , vital:71615
- Description: Climate change, severe weather events, population growth and, urbanisation are just a few of the leading causes contributing to the global water crisis. This global water crisis is negatively impacting the environment, and society, which includes business (large and small). Businesses are facing many water risks and challenges in their daily operations, such as water scarcity, water stress and water pollution, which are resulting in them being negatively impacted financially. For all business to overcome these risks and challenges which are negatively impacting their operations and to assist in protecting the scarce water resources left on the planet, the implementation of water stewardship practices will play a very important role. The literature has fallen short in addressing water stewardship frameworks and practices for small business. Through a sustainability lens underpinned by Natural Resource Based View Theory, this research study sets out to develop a water stewardship framework for implementation by small business to provide them with a competitive advantage. By reviewing the current literature and frameworks available to large business organisations, the insights gained allowed for a draft water stewardship framework to be developed from this literature, suitable for small business. This draft water stewardship framework for small business was used to gather further information on its suitability for small business, through an interview process. A qualitative interview process with seven small businesses in Makhanda (South Africa), allowed for data to be gathered and used to refine and adjust the draft water stewardship framework for small business. The findings from this research study show that small business do not have a global awareness of water problems and are not aware of the concept of water stewardship. Small business were very receptive to the draft water stewardship framework for small business and felt that its implementation would make a difference in saving scarce water resources and create a competitive advantage for them. The study concludes by recommending a water stewardship framework for small business (WSF4SB), who will play a leading role in fighting the water crisis. The implementation of the WSF4SB aims to provide small business with a sustainable competitive advantage by looking after scarce water resources ensuring there is sufficient water for current and future generations. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
- Date Issued: 2022-12-12
What is political corruption?: A philosophical analysis
- Authors: Onah, Gideon Owogeka
- Date: 2021-10-29
- Subjects: Political corruption , Political ethics , Political science Philosophy , Philp, Mark , Thompson, Dennis F (Dennis Frank), 1940- , Miller, Seumas
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192298 , vital:45213
- Description: The concept of political corruption is crucial in political discourses. Since the 1990s, there has been a massive resurgence of focus on political corruption. Definitional accounts of the concept have been proposed. This work is a critique of the accounts that have since been provided. I argue that these definitions are inadequate, offering an alternative. The predominant definition of the concept is that it refers to public officials’ violations of public office rules due to their respective interests in private gain. I consider this wrong for three reasons. First, politics includes more than the activities of public officials. Second, that is not the only behaviour that is contrary to the moral imperatives of politics. Third, the lack of political integrity is not just about acting wrongly. It also includes the possession of political vices. Observing the inadequacy of the dominant perspective, Seumas Miller offers a more comprehensive definition. He defines political corruption as any act that despoils the moral character of political actors and undermines the processes and purposes of legitimate political institutions. However, his definition is also insufficient. First, he includes some immoral non-political acts as examples of political corruption, although he agrees that political corruption entails immorality in politics. Second, he unjustifiably excludes some immoral political actions as denoting political corruption. In contrast, I define political corruption as possessing political vices or acting contrary to moral, political imperatives. This definition is a comprehensive reflection of what it means to lack political integrity. My thesis begins with a critical account of politics and its moral imperatives. That is the criteria for determining what political corruption is. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Onah, Gideon Owogeka
- Date: 2021-10-29
- Subjects: Political corruption , Political ethics , Political science Philosophy , Philp, Mark , Thompson, Dennis F (Dennis Frank), 1940- , Miller, Seumas
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192298 , vital:45213
- Description: The concept of political corruption is crucial in political discourses. Since the 1990s, there has been a massive resurgence of focus on political corruption. Definitional accounts of the concept have been proposed. This work is a critique of the accounts that have since been provided. I argue that these definitions are inadequate, offering an alternative. The predominant definition of the concept is that it refers to public officials’ violations of public office rules due to their respective interests in private gain. I consider this wrong for three reasons. First, politics includes more than the activities of public officials. Second, that is not the only behaviour that is contrary to the moral imperatives of politics. Third, the lack of political integrity is not just about acting wrongly. It also includes the possession of political vices. Observing the inadequacy of the dominant perspective, Seumas Miller offers a more comprehensive definition. He defines political corruption as any act that despoils the moral character of political actors and undermines the processes and purposes of legitimate political institutions. However, his definition is also insufficient. First, he includes some immoral non-political acts as examples of political corruption, although he agrees that political corruption entails immorality in politics. Second, he unjustifiably excludes some immoral political actions as denoting political corruption. In contrast, I define political corruption as possessing political vices or acting contrary to moral, political imperatives. This definition is a comprehensive reflection of what it means to lack political integrity. My thesis begins with a critical account of politics and its moral imperatives. That is the criteria for determining what political corruption is. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2021
- Full Text:
- Date Issued: 2021-10-29
Movement patterns of the iconic giant kingfish Caranx ignobilis from Southern Africa
- Authors: Dixon, Russell Bruce
- Date: 2022-10-14
- Subjects: Caranx Africa, Southern , Caranx Migration , Underwater acoustic telemetry , Carangidae Africa, Southern , Fish tagging
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362797 , vital:65363
- Description: Giant kingfish Caranx ignobilis, the largest species in the family Carangidae, are global icons as apex marine predators. They are widespread in tropical to subtropical regions globally, where they are of high importance to ecosystems and fisheries. During summer, adults aggregate for spawning, making them vulnerable to overfishing. The world’s largest recorded C. ignobilis aggregation is in southern Mozambique. Some of these aggregating individuals (an unknown proportion) have been recorded passing into South African waters. Furthermore, a unique aggregation of adult C. ignobilis in South Africa’s Mtentu Estuary has attracted global attention but remains unexplained, hence warranting investigation. Research on C. ignobilis globally has shown relatively small home ranges. Research in southern Africa has been limited and inconclusive. Thus, the broad aim of this study is to describe the movement patterns of C. ignobilis from southern Africa. Long-term (36 years) mark-recapture data from the Oceanographic Research Institute’s Co-operative Fish Tagging Project, comprising 3 729 tagged C. ignobilis and 144 recaptures, were analysed. While 74% of recaptures were recorded < 1 km from the tagging location, long-distance movements of up to 419 km were also recorded (mean = 15 km). Although adults moved significantly (p < 0.01) greater distances than juveniles, they also displayed high levels of site fidelity. Seasonal trends included evidence of a summer migration; however, there was still considerable uncertainty regarding exact movements. Therefore, 43 C. ignobilis were acoustically tagged and subsequently monitored along the east coast for over five years with the Acoustic Tracking Array Platform’s passive receiver array. All acoustically tagged adult C. ignobilis migrated to southern Mozambique each year (with minor exceptions), from distances of up to 632 km. When not migrating, South African-based fish showed consistent inter-annual fidelity to individual home ranges. Although coastal home range length (excluding migrations) varied considerably between individuals, even the mean length (92 km) was greater than any previously recorded C. ignobilis home range, globally. In contrast to the southern Mozambique aggregation, the Mtentu Estuary aggregation seems to comprise of individuals showing fidelity to that region. The passive tracking of eight acoustically tagged individuals in the Mtentu Estuary revealed clear trends. Statistical modelling showed that estuarine presence was strongly associated with periods of cold coastal upwelling. Diel movement patterns showed that the utilisation of warm surface waters ~ 4 km upstream during the day was followed by nightly departures to the mouth or sea. Thus, it is likely that this majestic aggregation is for thermal refuge; specifically, for daily re-warming after feeding in cold waters at night. Findings from this study are of global ecological interest and have direct applications for local fisheries management and the development of sustainable eco-tourism. Protecting these vulnerable aggregations is of the utmost importance for the future of this species in southern Africa. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Dixon, Russell Bruce
- Date: 2022-10-14
- Subjects: Caranx Africa, Southern , Caranx Migration , Underwater acoustic telemetry , Carangidae Africa, Southern , Fish tagging
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362797 , vital:65363
- Description: Giant kingfish Caranx ignobilis, the largest species in the family Carangidae, are global icons as apex marine predators. They are widespread in tropical to subtropical regions globally, where they are of high importance to ecosystems and fisheries. During summer, adults aggregate for spawning, making them vulnerable to overfishing. The world’s largest recorded C. ignobilis aggregation is in southern Mozambique. Some of these aggregating individuals (an unknown proportion) have been recorded passing into South African waters. Furthermore, a unique aggregation of adult C. ignobilis in South Africa’s Mtentu Estuary has attracted global attention but remains unexplained, hence warranting investigation. Research on C. ignobilis globally has shown relatively small home ranges. Research in southern Africa has been limited and inconclusive. Thus, the broad aim of this study is to describe the movement patterns of C. ignobilis from southern Africa. Long-term (36 years) mark-recapture data from the Oceanographic Research Institute’s Co-operative Fish Tagging Project, comprising 3 729 tagged C. ignobilis and 144 recaptures, were analysed. While 74% of recaptures were recorded < 1 km from the tagging location, long-distance movements of up to 419 km were also recorded (mean = 15 km). Although adults moved significantly (p < 0.01) greater distances than juveniles, they also displayed high levels of site fidelity. Seasonal trends included evidence of a summer migration; however, there was still considerable uncertainty regarding exact movements. Therefore, 43 C. ignobilis were acoustically tagged and subsequently monitored along the east coast for over five years with the Acoustic Tracking Array Platform’s passive receiver array. All acoustically tagged adult C. ignobilis migrated to southern Mozambique each year (with minor exceptions), from distances of up to 632 km. When not migrating, South African-based fish showed consistent inter-annual fidelity to individual home ranges. Although coastal home range length (excluding migrations) varied considerably between individuals, even the mean length (92 km) was greater than any previously recorded C. ignobilis home range, globally. In contrast to the southern Mozambique aggregation, the Mtentu Estuary aggregation seems to comprise of individuals showing fidelity to that region. The passive tracking of eight acoustically tagged individuals in the Mtentu Estuary revealed clear trends. Statistical modelling showed that estuarine presence was strongly associated with periods of cold coastal upwelling. Diel movement patterns showed that the utilisation of warm surface waters ~ 4 km upstream during the day was followed by nightly departures to the mouth or sea. Thus, it is likely that this majestic aggregation is for thermal refuge; specifically, for daily re-warming after feeding in cold waters at night. Findings from this study are of global ecological interest and have direct applications for local fisheries management and the development of sustainable eco-tourism. Protecting these vulnerable aggregations is of the utmost importance for the future of this species in southern Africa. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-10-14
Prosecution of forced marriage by international courts and tribunals in light of the principle of legality
- Okeyo, Julian Rebecca Atieno
- Authors: Okeyo, Julian Rebecca Atieno
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/420720 , vital:71772
- Description: Thesis embargoed. Probable release date in 2024. , Thesis (LLM) -- Faculty of Law, Law, 2023
- Full Text:
- Date Issued: 2023-03-29
- Authors: Okeyo, Julian Rebecca Atieno
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/420720 , vital:71772
- Description: Thesis embargoed. Probable release date in 2024. , Thesis (LLM) -- Faculty of Law, Law, 2023
- Full Text:
- Date Issued: 2023-03-29
The de novo biosynthesis of biotin is required for the optimal growth of Salmonella enterica serovar Typhimurium in the intracellular environment
- Authors: McLaughlin, Claire
- Date: 2021-10-29
- Subjects: Salmonella , Biotin , Biosynthesis , Salmonella typhimurium , Antibacterial agents , Anti-infective agents , Pathogenic bacteria , Salmonella food poisoning
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192097 , vital:45195
- Description: Salmonella enterica serovar Typhimurium (S. Typhimurium) is a foodborne pathogen infecting humans and animals, contributing to significant morbidity and mortality worldwide each year. The increase in antibiotic-resistant S. Typhimurium infections in recent years has highlighted the need for new antibacterial drugs and drug targets. S. Typhimurium can acquire biotin through de novo biosynthesis or via transport from its extracellular environment. The importance of the vitamin for bacterial survival, coupled with the absence of the biotin biosynthetic pathway in humans, makes the biotin biosynthetic enzymes attractive targets for drug discovery. The study's primary aim was to determine the relative importance of the biotin biosynthesis and transport pathways for the in vitro and ex vivo growth and survival of S. Typhimurium, with the goal of validating the pathways as valid targets for antimicrobial drug development. In order to achieve this aim, we generated S. Typhimurium mutant strains harbouring deletions in either the biotin biosynthetic gene, bioB, or putative high-affinity biotin transporter, yigM (ΔbioB and ΔyigM, respectively), as well as a double mutant in which the two mutations were combined (ΔbioB ΔyigM). Since the simultaneous disruption of biotin biosynthesis and transport in the double mutant may form a synthetic lethal combination, preventing further analysis of the strain, we also constructed a conditional mutant in which the promoter of the yigM gene was replaced by the arabinose-regulatable, PBAD promoter in the ΔbioB background (ΔbioB PBAD::yigM). Since the expression of the YigM in this strain is arabinose-regulatable, its role as a biotin transporter can be evaluated by altering the arabinose concentration in the growth media. Once the mutant strains were isolated and verified genetically, their growth and that of their genetically complemented counterparts were analysed in liquid and/or solid M9 minimal medium in the absence of biotin. Consistent with previous observations, the ΔbioB auxotrophic mutant's growth was severely compromised in minimal media in the absence of biotin. The growth of the strain could, however, be restored by supplementation with exogenous biotin or expression of the wild type bioB gene from an episomal plasmid. The ability of biotin to reverse the growth defect of the ΔbioB mutant strain was, however, dependent on the presence of a functional YigM, since biotin supplementation did not affect the growth of the ΔbioB ΔyigM double mutant strain. The introduction of a second copy of the yigM gene in the ΔbioB ΔyigM background, however, restored the growth of the strain in the presence, but not absence, of biotin. The dependence of the double mutant on both YigM and biotin for growth supports the idea that the protein functions as the sole or primary biotin transporter in S. Typhimurium, as it has recently been shown for E. coli (Ringsletter, 2010; Finkenwirth et al, 2013). The essentiality of YigM for biotin transport was subsequently verified by two independent means. Firstly, the growth of the ΔbioB PBAD::yigM promoter-replacement mutant was strictly dependent on the inclusion of arabinose in biotin-supplemented M9 minimal media supplemented, indicating that the expression of YigM from the PBAD promoter is essential for biotin transport. Secondly, following treatment with a known small-molecule inhibitor of the biotin biosynthesis, MAC-13772, exogenous biotin was capable of restoring the growth defect of the YigM+ wild type S. Typhimurium strain, but not the YigM− ΔyigM mutant. Taken together, these findings confirm that YigM serves as the biotin transporter for S. Typhimurium and that the corresponding ΔyigM mutant is, as a result, defective for biotin transport. Having confirmed the genotypes and phenotypes of the ΔbioB, ΔyigM, and ΔbioB ΔyigM mutants, we next analysed the importance of the biotin biosynthesis and transport pathways for the growth and survival of S. Typhimurium within the intracellular environment. To this end, we determined the proliferation of each of the mutant strains following infection of HeLa epithelial and RAW264.7 macrophage-like cell lines. Our results revealed that the de novo biosynthesis of biotin is required for the optimal growth of S. Typhimurium following infection of both epithelial and macrophage-like cell lines. Disruption of biotin transport, by contrast, had no significant effect on the intracellular proliferation of S. Typhimurium when a functional pathway for the biosynthesis of biotin was present. The simultaneous disruption of biotin biosynthesis and transport, however, resulted in significant attenuation of S. Typhimurium in epithelial cells, while bacterial survival in macrophages decreased to below the limit of detection. Overall, our results suggest the S. Typhimurium relies primarily on biotin produced by the de novo biosynthesis pathway to support its growth in the intracellular environment. While YigM-mediated biotin transport is essential for sustaining the viability of intracellular S. Typhimurium in the absence of de novo biosynthesis, it appears to play a relatively minor role in the acquisition of biotin during growth in the nutrient-limited Salmonella containing vacuole. Our findings suggest that inhibiting biotin biosynthesis may be a viable strategy for combating systemic infections caused by Salmonella, as has been recently proposed for other medically important bacterial pathogens (Carfrae et al., 2020). , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: McLaughlin, Claire
- Date: 2021-10-29
- Subjects: Salmonella , Biotin , Biosynthesis , Salmonella typhimurium , Antibacterial agents , Anti-infective agents , Pathogenic bacteria , Salmonella food poisoning
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192097 , vital:45195
- Description: Salmonella enterica serovar Typhimurium (S. Typhimurium) is a foodborne pathogen infecting humans and animals, contributing to significant morbidity and mortality worldwide each year. The increase in antibiotic-resistant S. Typhimurium infections in recent years has highlighted the need for new antibacterial drugs and drug targets. S. Typhimurium can acquire biotin through de novo biosynthesis or via transport from its extracellular environment. The importance of the vitamin for bacterial survival, coupled with the absence of the biotin biosynthetic pathway in humans, makes the biotin biosynthetic enzymes attractive targets for drug discovery. The study's primary aim was to determine the relative importance of the biotin biosynthesis and transport pathways for the in vitro and ex vivo growth and survival of S. Typhimurium, with the goal of validating the pathways as valid targets for antimicrobial drug development. In order to achieve this aim, we generated S. Typhimurium mutant strains harbouring deletions in either the biotin biosynthetic gene, bioB, or putative high-affinity biotin transporter, yigM (ΔbioB and ΔyigM, respectively), as well as a double mutant in which the two mutations were combined (ΔbioB ΔyigM). Since the simultaneous disruption of biotin biosynthesis and transport in the double mutant may form a synthetic lethal combination, preventing further analysis of the strain, we also constructed a conditional mutant in which the promoter of the yigM gene was replaced by the arabinose-regulatable, PBAD promoter in the ΔbioB background (ΔbioB PBAD::yigM). Since the expression of the YigM in this strain is arabinose-regulatable, its role as a biotin transporter can be evaluated by altering the arabinose concentration in the growth media. Once the mutant strains were isolated and verified genetically, their growth and that of their genetically complemented counterparts were analysed in liquid and/or solid M9 minimal medium in the absence of biotin. Consistent with previous observations, the ΔbioB auxotrophic mutant's growth was severely compromised in minimal media in the absence of biotin. The growth of the strain could, however, be restored by supplementation with exogenous biotin or expression of the wild type bioB gene from an episomal plasmid. The ability of biotin to reverse the growth defect of the ΔbioB mutant strain was, however, dependent on the presence of a functional YigM, since biotin supplementation did not affect the growth of the ΔbioB ΔyigM double mutant strain. The introduction of a second copy of the yigM gene in the ΔbioB ΔyigM background, however, restored the growth of the strain in the presence, but not absence, of biotin. The dependence of the double mutant on both YigM and biotin for growth supports the idea that the protein functions as the sole or primary biotin transporter in S. Typhimurium, as it has recently been shown for E. coli (Ringsletter, 2010; Finkenwirth et al, 2013). The essentiality of YigM for biotin transport was subsequently verified by two independent means. Firstly, the growth of the ΔbioB PBAD::yigM promoter-replacement mutant was strictly dependent on the inclusion of arabinose in biotin-supplemented M9 minimal media supplemented, indicating that the expression of YigM from the PBAD promoter is essential for biotin transport. Secondly, following treatment with a known small-molecule inhibitor of the biotin biosynthesis, MAC-13772, exogenous biotin was capable of restoring the growth defect of the YigM+ wild type S. Typhimurium strain, but not the YigM− ΔyigM mutant. Taken together, these findings confirm that YigM serves as the biotin transporter for S. Typhimurium and that the corresponding ΔyigM mutant is, as a result, defective for biotin transport. Having confirmed the genotypes and phenotypes of the ΔbioB, ΔyigM, and ΔbioB ΔyigM mutants, we next analysed the importance of the biotin biosynthesis and transport pathways for the growth and survival of S. Typhimurium within the intracellular environment. To this end, we determined the proliferation of each of the mutant strains following infection of HeLa epithelial and RAW264.7 macrophage-like cell lines. Our results revealed that the de novo biosynthesis of biotin is required for the optimal growth of S. Typhimurium following infection of both epithelial and macrophage-like cell lines. Disruption of biotin transport, by contrast, had no significant effect on the intracellular proliferation of S. Typhimurium when a functional pathway for the biosynthesis of biotin was present. The simultaneous disruption of biotin biosynthesis and transport, however, resulted in significant attenuation of S. Typhimurium in epithelial cells, while bacterial survival in macrophages decreased to below the limit of detection. Overall, our results suggest the S. Typhimurium relies primarily on biotin produced by the de novo biosynthesis pathway to support its growth in the intracellular environment. While YigM-mediated biotin transport is essential for sustaining the viability of intracellular S. Typhimurium in the absence of de novo biosynthesis, it appears to play a relatively minor role in the acquisition of biotin during growth in the nutrient-limited Salmonella containing vacuole. Our findings suggest that inhibiting biotin biosynthesis may be a viable strategy for combating systemic infections caused by Salmonella, as has been recently proposed for other medically important bacterial pathogens (Carfrae et al., 2020). , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-10-29
Protecting the right to identity against catfishing
- Authors: Ndyulo, Lisa Neliswa Latima
- Date: 2022-04-06
- Subjects: Catfishing South Africa , False personation Law and legislation South Africa , Torts South Africa , Mass media and publicity South Africa , Social media Law and legislation South Africa , Identity theft Law and legislation South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290767 , vital:56782
- Description: Catfishing is a form of impersonation occurring on social media that interferes with a person’s right to identity. It involves creating a fake profile online using another person’s images. The facets of the right to identity are image, name, and likeness, among others. Catfishing affects a person’s right to identity and human dignity. Hence, the thesis aims to determine whether the right to identity adequately protects individuals against catfishing. This thesis is a desktop analysis considering the South African legal framework related to the right to identity, including the common law, the Constitution of the Republic of South Africa, 1996, and legislation. The thesis is also a comparative analysis assessing the adequacy of addressing catfishing through the right to identity. The study evaluates the right to identity’s adequacy by juxtaposing the South African legal framework with California and Oklahoma’s common law and statutory interventions. The study reveals that the right to identity protects South African social networking website users against catfishing. Like the common law right of privacy in California and Oklahoma, a person infringes the right to identity when they use another person’s identity facets to portray them in a false light, and like the statutory right of publicity in California and Oklahoma, a person infringes identity when they appropriate facets of another person’s identity for commercial gain. The infringement of the right to identity entitles a person to legal remedies, including a claim for damages, among other things. The thesis also considers principles of conflict of laws to determine the operative law in an instance where a victim resides in South Africa and the perpetrator resides in the US, or vice versa. The study recommends that developing the common law to recognise that identity can be infringed by mere appropriation not linked to a commercial purpose would be beneficial for addressing catfishing adequately in South Africa. Legal development contributes to the constitutional imperative to align the common law with society’s shifting needs and address novel legal issues, such as catfishing. , Thesis (LLM) -- Faculty of Law, Law, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Ndyulo, Lisa Neliswa Latima
- Date: 2022-04-06
- Subjects: Catfishing South Africa , False personation Law and legislation South Africa , Torts South Africa , Mass media and publicity South Africa , Social media Law and legislation South Africa , Identity theft Law and legislation South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290767 , vital:56782
- Description: Catfishing is a form of impersonation occurring on social media that interferes with a person’s right to identity. It involves creating a fake profile online using another person’s images. The facets of the right to identity are image, name, and likeness, among others. Catfishing affects a person’s right to identity and human dignity. Hence, the thesis aims to determine whether the right to identity adequately protects individuals against catfishing. This thesis is a desktop analysis considering the South African legal framework related to the right to identity, including the common law, the Constitution of the Republic of South Africa, 1996, and legislation. The thesis is also a comparative analysis assessing the adequacy of addressing catfishing through the right to identity. The study evaluates the right to identity’s adequacy by juxtaposing the South African legal framework with California and Oklahoma’s common law and statutory interventions. The study reveals that the right to identity protects South African social networking website users against catfishing. Like the common law right of privacy in California and Oklahoma, a person infringes the right to identity when they use another person’s identity facets to portray them in a false light, and like the statutory right of publicity in California and Oklahoma, a person infringes identity when they appropriate facets of another person’s identity for commercial gain. The infringement of the right to identity entitles a person to legal remedies, including a claim for damages, among other things. The thesis also considers principles of conflict of laws to determine the operative law in an instance where a victim resides in South Africa and the perpetrator resides in the US, or vice versa. The study recommends that developing the common law to recognise that identity can be infringed by mere appropriation not linked to a commercial purpose would be beneficial for addressing catfishing adequately in South Africa. Legal development contributes to the constitutional imperative to align the common law with society’s shifting needs and address novel legal issues, such as catfishing. , Thesis (LLM) -- Faculty of Law, Law, 2022
- Full Text:
- Date Issued: 2022-04-06