An analysis of the precarious livelihoods of Zimbabwean migrants in the informal economy in Makhanda, South Africa
- Authors: Nderere, Nompumelelo Agnes
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/466262 , vital:76712
- Description: The movement of people across borders is a complex phenomenon that has far-reaching social, political, and economic implications. In recent years, Zimbabwean migrants have become increasingly visible in the informal economy across South Africa. Through qualitative data collection methods, this study sought to broaden our understanding of the precarious livelihoods of Zimbabwean migrants working in the informal economy in South Africa. This study examined Zimbabwean migrants in the informal economy in Makhanda, Eastern Cape in South Africa. Underpinned by the Sustainable Livelihoods Approach (SLA) as the theoretical anchor, this thesis offers a comprehensive examination of not only the challenges but also the opportunities faced and presented to Zimbabwean migrants in the informal economy in Makhanda. The Sustainable Livelihoods Approach was used as a framework to guide the analysis aimed at understanding the precarious livelihoods of Zimbabwean migrants working in the informal economy in terms of the vulnerability context they find themselves in, the assets they use, the organizations or institutions that affect their activities and the results they get out of their efforts in the informal economy. Data was collected from a sample of 10 participants, consisting of 4 self-employed participants and 6 “employed” in the informal economy. Through in-depth interviews and thematic analysis, this thesis examined the strategies that the migrants adopt to cope with the challenges they face and the impact that these strategies have on their livelihoods. The findings suggest that working in the informal economy evolves as a sustainable livelihood strategy, which depends on external support for it to flourish. , Thesis (MSocSci) -- Faculty of Humanities, Sociology, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Nderere, Nompumelelo Agnes
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/466262 , vital:76712
- Description: The movement of people across borders is a complex phenomenon that has far-reaching social, political, and economic implications. In recent years, Zimbabwean migrants have become increasingly visible in the informal economy across South Africa. Through qualitative data collection methods, this study sought to broaden our understanding of the precarious livelihoods of Zimbabwean migrants working in the informal economy in South Africa. This study examined Zimbabwean migrants in the informal economy in Makhanda, Eastern Cape in South Africa. Underpinned by the Sustainable Livelihoods Approach (SLA) as the theoretical anchor, this thesis offers a comprehensive examination of not only the challenges but also the opportunities faced and presented to Zimbabwean migrants in the informal economy in Makhanda. The Sustainable Livelihoods Approach was used as a framework to guide the analysis aimed at understanding the precarious livelihoods of Zimbabwean migrants working in the informal economy in terms of the vulnerability context they find themselves in, the assets they use, the organizations or institutions that affect their activities and the results they get out of their efforts in the informal economy. Data was collected from a sample of 10 participants, consisting of 4 self-employed participants and 6 “employed” in the informal economy. Through in-depth interviews and thematic analysis, this thesis examined the strategies that the migrants adopt to cope with the challenges they face and the impact that these strategies have on their livelihoods. The findings suggest that working in the informal economy evolves as a sustainable livelihood strategy, which depends on external support for it to flourish. , Thesis (MSocSci) -- Faculty of Humanities, Sociology, 2024
- Full Text:
- Date Issued: 2024-10-11
Cocrystals, salts and eutectics of anti-tuberculosis medicines
- Authors: Matlapeng, Tsebang Alice
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464521 , vital:76518
- Description: Tuberculosis remains as a prominent cause of death worldwide. This infectious disease is treated with first and second line drugs. However, challenges of multi drug resistant tuberculosis and adverse side effects such as depletion of essential B group vitamins in the body by first line drugs, as well as poor physicochemical properties of second line drugs persist. Cocrystallisation of anti-tubercular drugs with various coformers has therefore been used as an alternative method to improve the physicochemical properties of active pharmaceutical ingredients (API) while maintaining their efficacy. The main objective of this study was to carry out cocrystal screening of anti-tubercular API and vitamin B coformers to make drug-drug or drug-vitamin multicomponent complexes. Preparation of the multicomponent complexes was carried out by mechanochemical grinding (neat grinding (NG), liquid assisted grinding (LAG) and slow evaporation. All complexes were characterised using Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and crystal structures were elucidated using single-crystal X-ray diffraction (SCXRD). The cocrystal screening resulted in the formation of various solid forms, which included cocrystals, salts and eutectic products. Two cocrystals of 4-aminosalicylic acid (PAS) were isolated and characterised. The cocrystal of PAS with isoniazid (INH) demonstrated similar characteristics for both the bulk crystalline material and milled materials. The cocrystal of PAS and pyrazinamide (PYR) prepared using mechanochemical synthesis was met with challenges, while difficulties were also encountered in obtaining suitable crystals for SCXRD analysis. The ground and recrystallised samples of the PAS and pyrazinecarboxylic acid (PCBA) showed distinct differences in their thermal behaviour, with SCXRD revealing the decomposition product phenolammonium-pyrazinecarboxylate salt ‘sans’ the CO2 moiety. Salt formation involving pyridoxine (PN) yielded a salt hydrate with PAS (PN-PAS) and an anhydrous salt with PCBA (PN-PCBA). Both salts exhibited very complex packing arrangements with equally complex thermal behaviour depending on the solvent used during preparation, and the method of preparation. Three eutectic systems involving INH with PYR, PN and pyridoxine hydrochloride (PNꞏHCl) were identified, and their phase diagrams were constructed from DSC data. The eutectic compositions obtained were 1:1 for INH:PYR, 1:1 for INH:PN and 6:4 for INH:PNꞏHCl. Finally, a total of eight multicomponent complexes were prepared using selected API and vitamin B6 components. The results presented here provide motivation for further investigation and evaluation of the pharmacochemical properties of these API. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Matlapeng, Tsebang Alice
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464521 , vital:76518
- Description: Tuberculosis remains as a prominent cause of death worldwide. This infectious disease is treated with first and second line drugs. However, challenges of multi drug resistant tuberculosis and adverse side effects such as depletion of essential B group vitamins in the body by first line drugs, as well as poor physicochemical properties of second line drugs persist. Cocrystallisation of anti-tubercular drugs with various coformers has therefore been used as an alternative method to improve the physicochemical properties of active pharmaceutical ingredients (API) while maintaining their efficacy. The main objective of this study was to carry out cocrystal screening of anti-tubercular API and vitamin B coformers to make drug-drug or drug-vitamin multicomponent complexes. Preparation of the multicomponent complexes was carried out by mechanochemical grinding (neat grinding (NG), liquid assisted grinding (LAG) and slow evaporation. All complexes were characterised using Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and crystal structures were elucidated using single-crystal X-ray diffraction (SCXRD). The cocrystal screening resulted in the formation of various solid forms, which included cocrystals, salts and eutectic products. Two cocrystals of 4-aminosalicylic acid (PAS) were isolated and characterised. The cocrystal of PAS with isoniazid (INH) demonstrated similar characteristics for both the bulk crystalline material and milled materials. The cocrystal of PAS and pyrazinamide (PYR) prepared using mechanochemical synthesis was met with challenges, while difficulties were also encountered in obtaining suitable crystals for SCXRD analysis. The ground and recrystallised samples of the PAS and pyrazinecarboxylic acid (PCBA) showed distinct differences in their thermal behaviour, with SCXRD revealing the decomposition product phenolammonium-pyrazinecarboxylate salt ‘sans’ the CO2 moiety. Salt formation involving pyridoxine (PN) yielded a salt hydrate with PAS (PN-PAS) and an anhydrous salt with PCBA (PN-PCBA). Both salts exhibited very complex packing arrangements with equally complex thermal behaviour depending on the solvent used during preparation, and the method of preparation. Three eutectic systems involving INH with PYR, PN and pyridoxine hydrochloride (PNꞏHCl) were identified, and their phase diagrams were constructed from DSC data. The eutectic compositions obtained were 1:1 for INH:PYR, 1:1 for INH:PN and 6:4 for INH:PNꞏHCl. Finally, a total of eight multicomponent complexes were prepared using selected API and vitamin B6 components. The results presented here provide motivation for further investigation and evaluation of the pharmacochemical properties of these API. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
“But we are shying all of us away, from that thing”: the Coronavirus Pandemic and the crisis of teenage pregnancies in Kenya
- Authors: Kipury, Siraiyion Soinda
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/465989 , vital:76674
- Description: This thesis historicises the post-colonial discourse on teenage pregnancy in Kenya. The coronavirus pandemic lockdowns in 2020 led to an increase in sexual violence perpetrated largely against teenage girls, resulting in pregnancy. This crisis revealed that the current discourse has created silence around sex and rape. It therefore does not consider the circumstances surrounding the pregnancies of teenage girls and for that reason perpetuates stereotypes of them being poor, irresponsible, dropouts. It finds that these ideas materialise in the form of adolescent sexual and reproductive health legislation which has real effects on pregnant teenage girls. Through a lack of law and policy enforcement, the discourse legitimises itself in a cyclic fashion. It argues that understanding the way the discourse has perpetuated itself from the past into the present is key to transforming this legislation and therefore their experiences. It uses an Oral History methodology to centre the perspectives of women who had teenage pregnancies in the past, and uses their stories to develop an understanding of how the discourse functions. It identifies news media and legislation as two major sites of discourse, carrying out an analysis of the language and content exhibited to observe the way cultural stereotypes around teenage pregnancy are preserved and re-created. It draws parallels between past and present sexual and reproductive health laws (1963-2020) to demonstrate the longevity of gendered and misogynistic ideologies surrounding women’s sexuality. It finds that language, blame/shame, and exclusion are the means through which the discourse has impressed itself upon Kenyan society throughout the post-colonial period. This thesis concludes that becoming aware of these means renders the discourse abnormal and unnatural, therefore creating the possibility of opening it up to change. , Thesis (MA) -- Faculty of Humanities, History, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Kipury, Siraiyion Soinda
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/465989 , vital:76674
- Description: This thesis historicises the post-colonial discourse on teenage pregnancy in Kenya. The coronavirus pandemic lockdowns in 2020 led to an increase in sexual violence perpetrated largely against teenage girls, resulting in pregnancy. This crisis revealed that the current discourse has created silence around sex and rape. It therefore does not consider the circumstances surrounding the pregnancies of teenage girls and for that reason perpetuates stereotypes of them being poor, irresponsible, dropouts. It finds that these ideas materialise in the form of adolescent sexual and reproductive health legislation which has real effects on pregnant teenage girls. Through a lack of law and policy enforcement, the discourse legitimises itself in a cyclic fashion. It argues that understanding the way the discourse has perpetuated itself from the past into the present is key to transforming this legislation and therefore their experiences. It uses an Oral History methodology to centre the perspectives of women who had teenage pregnancies in the past, and uses their stories to develop an understanding of how the discourse functions. It identifies news media and legislation as two major sites of discourse, carrying out an analysis of the language and content exhibited to observe the way cultural stereotypes around teenage pregnancy are preserved and re-created. It draws parallels between past and present sexual and reproductive health laws (1963-2020) to demonstrate the longevity of gendered and misogynistic ideologies surrounding women’s sexuality. It finds that language, blame/shame, and exclusion are the means through which the discourse has impressed itself upon Kenyan society throughout the post-colonial period. This thesis concludes that becoming aware of these means renders the discourse abnormal and unnatural, therefore creating the possibility of opening it up to change. , Thesis (MA) -- Faculty of Humanities, History, 2024
- Full Text:
- Date Issued: 2024-10-11
Towards a possible future solution against Multidrug Resistance: An in silico exploration of the Multidrug and Toxic compound Extrusion (MATE) transporter proteins as potential antimicrobial drug targets
- Authors: Damji, Amira Mahamood
- Date: 2024-04-04
- Subjects: Multidrug resistance , Multidrug and toxic compound extrusion family, eukaryotic , Docking , Molecular dynamics , Drug development , Transmembrane protein
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/435009 , vital:73123
- Description: The rise of multidrug resistance (MDR) has become a pressing global issue, hindering the treatment of cancers and infectious diseases, and imposing a burden on healthcare systems and the economy. The Multidrug and Toxic compound Extrusion (MATE) superfamily of membrane efflux transporters is one of the key players contributing to MDR due to their ability to export a wide range of cationic and hydrophilic xenobiotics, including treatment drugs, from cells, diminishing their efficacy. Targeting MATE transporters holds great promise in achieving some cellular control over MDR, but first, a deeper understanding of their structure-function-dynamics link is required. This study aimed to explore the MATE transporters as potential antimicrobial drug targets using a two-fold in silico approach. First, virtual screening of compounds from the South African Natural Compounds Database (SANCDB) was performed to identify prospective lead inhibitory compounds against the MATE transporters using molecular docking, and top hits were selected based on their binding energy and interaction with the active site on the N-lobe of the protein. Second, to investigate the molecular-level dynamics of their extrusion mechanism, the MATE transporter structures were embedded in a POPC membrane bilayer using the CHARMM-GUI online tool and then subjected to MD simulations for 100 ns with the CHARMM 36m force field using GROMACS. The resulting trajectories were evaluated using three standard metrics – RMSD, RMSF, and Rg; significant global structural changes were observed and key functional regions in both membrane- and non-membrane transmembrane (TM) segments were identified, containing more dynamic and flexible residues than other regions. Furthermore, the MATE transporters showed more of a loosely-packed structure, providing flexibility to allow for conformational switching during their substrate-transport cycle, which is typical for proteins whose secondary structures are composed of all α-helices. The scope of this study lied in the preliminary stages of the computer-aided drug design process, and provided insights that can be used to guide the development of strategies aimed at regulating or inhibiting the function of the MATE transporters, offering a possible future solution to the growing challenge of MDR. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2024
- Full Text:
- Date Issued: 2024-04-04
- Authors: Damji, Amira Mahamood
- Date: 2024-04-04
- Subjects: Multidrug resistance , Multidrug and toxic compound extrusion family, eukaryotic , Docking , Molecular dynamics , Drug development , Transmembrane protein
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/435009 , vital:73123
- Description: The rise of multidrug resistance (MDR) has become a pressing global issue, hindering the treatment of cancers and infectious diseases, and imposing a burden on healthcare systems and the economy. The Multidrug and Toxic compound Extrusion (MATE) superfamily of membrane efflux transporters is one of the key players contributing to MDR due to their ability to export a wide range of cationic and hydrophilic xenobiotics, including treatment drugs, from cells, diminishing their efficacy. Targeting MATE transporters holds great promise in achieving some cellular control over MDR, but first, a deeper understanding of their structure-function-dynamics link is required. This study aimed to explore the MATE transporters as potential antimicrobial drug targets using a two-fold in silico approach. First, virtual screening of compounds from the South African Natural Compounds Database (SANCDB) was performed to identify prospective lead inhibitory compounds against the MATE transporters using molecular docking, and top hits were selected based on their binding energy and interaction with the active site on the N-lobe of the protein. Second, to investigate the molecular-level dynamics of their extrusion mechanism, the MATE transporter structures were embedded in a POPC membrane bilayer using the CHARMM-GUI online tool and then subjected to MD simulations for 100 ns with the CHARMM 36m force field using GROMACS. The resulting trajectories were evaluated using three standard metrics – RMSD, RMSF, and Rg; significant global structural changes were observed and key functional regions in both membrane- and non-membrane transmembrane (TM) segments were identified, containing more dynamic and flexible residues than other regions. Furthermore, the MATE transporters showed more of a loosely-packed structure, providing flexibility to allow for conformational switching during their substrate-transport cycle, which is typical for proteins whose secondary structures are composed of all α-helices. The scope of this study lied in the preliminary stages of the computer-aided drug design process, and provided insights that can be used to guide the development of strategies aimed at regulating or inhibiting the function of the MATE transporters, offering a possible future solution to the growing challenge of MDR. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2024
- Full Text:
- Date Issued: 2024-04-04
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
Variables associated with run out opportunities in cricket: coaches’ perceptions versus video analyses of the Indian Premier League 2018/2019 seasons
- Authors: Sholto-Douglas, Robert
- Date: 2022-10-14
- Subjects: Indian Premier League , Cricket Coaching , Video analysis , Fielding , Run out
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365014 , vital:65670
- Description: The purpose of this investigation was to add a scientific element to the understanding of run out opportunities in T20 (twenty/twenty) formats, which would in turn, provide recommendations to players and coaches around the topic of run outs. Due to a lack of research in this field, the study was two-fold, as there is little research known on this topic. Firstly, surveying experienced coaches on what they would expect to take place during run out opportunities from different areas of the field in a T20 game. Secondly, the study looked at what happened during successful and unsuccessful run outs from different areas of the field in two Indian Premier League (IPL) seasons. The aim of the study was to determine what variables, within an area of fielding, led to a successful or non-successful run out from different zones in the field. Coaches were required to fill out a survey which asked them to give their expectations on run out opportunities during a T20 competition. The data from the questionnaire would be used to gain a greater understanding of the way coaches understand different characteristics of run outs and whether this matched the findings of the second part of this study. The second part of the study investigated run out opportunities in two consecutive IPL seasons, based on video footage, looking at how different variables impacted successful or marginally missed run out opportunities in different areas of the field and at different times of the game. The areas were put into four different zones. Zone 1 being close to the batter, zone 2 being in the inner ring, zone 3 being on the edge of the ring and zone 4 being boundary fielders. Most of the coaches believed that in zone 1 of the field, the bowler would have the most opportunities, where in fact, based on the video footage, these fell to the wicket-keeper. In zone 2 there were a larger range of fielding positions (10) that run outs fell to when analysing video footage. The coaches supported this by often naming the same fielding positions. There was a divide in zone 3. Most run out opportunities from the video footage came to extra cover, where most coaches didn’t believe that would be the case and rather mentioned mid-off and mid-on. When analysing video footage in zone 4, it had two fielding positions (long on and deep mid-wicket) make up the majority of run out chances in this area and these two positions were quoted by most of the coaches as having the most run out opportunities fall to them. Throughout the findings, as concluded from the video footage, there were some results that matched the coaches’ expectation and some results where findings from the video footage differed from the coaches’ expectations. These findings are all useful. Firstly, it validates coaching practices. Secondly, it provides coaches with greater insight as to where they aren’t getting it correct in their fielding training. In conclusion, this study found that although coaches perceptions, for the most part, matched what took place on the field, there were instances where we saw the opposite action take place. This has important practical implications for coaching and practice. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Sholto-Douglas, Robert
- Date: 2022-10-14
- Subjects: Indian Premier League , Cricket Coaching , Video analysis , Fielding , Run out
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365014 , vital:65670
- Description: The purpose of this investigation was to add a scientific element to the understanding of run out opportunities in T20 (twenty/twenty) formats, which would in turn, provide recommendations to players and coaches around the topic of run outs. Due to a lack of research in this field, the study was two-fold, as there is little research known on this topic. Firstly, surveying experienced coaches on what they would expect to take place during run out opportunities from different areas of the field in a T20 game. Secondly, the study looked at what happened during successful and unsuccessful run outs from different areas of the field in two Indian Premier League (IPL) seasons. The aim of the study was to determine what variables, within an area of fielding, led to a successful or non-successful run out from different zones in the field. Coaches were required to fill out a survey which asked them to give their expectations on run out opportunities during a T20 competition. The data from the questionnaire would be used to gain a greater understanding of the way coaches understand different characteristics of run outs and whether this matched the findings of the second part of this study. The second part of the study investigated run out opportunities in two consecutive IPL seasons, based on video footage, looking at how different variables impacted successful or marginally missed run out opportunities in different areas of the field and at different times of the game. The areas were put into four different zones. Zone 1 being close to the batter, zone 2 being in the inner ring, zone 3 being on the edge of the ring and zone 4 being boundary fielders. Most of the coaches believed that in zone 1 of the field, the bowler would have the most opportunities, where in fact, based on the video footage, these fell to the wicket-keeper. In zone 2 there were a larger range of fielding positions (10) that run outs fell to when analysing video footage. The coaches supported this by often naming the same fielding positions. There was a divide in zone 3. Most run out opportunities from the video footage came to extra cover, where most coaches didn’t believe that would be the case and rather mentioned mid-off and mid-on. When analysing video footage in zone 4, it had two fielding positions (long on and deep mid-wicket) make up the majority of run out chances in this area and these two positions were quoted by most of the coaches as having the most run out opportunities fall to them. Throughout the findings, as concluded from the video footage, there were some results that matched the coaches’ expectation and some results where findings from the video footage differed from the coaches’ expectations. These findings are all useful. Firstly, it validates coaching practices. Secondly, it provides coaches with greater insight as to where they aren’t getting it correct in their fielding training. In conclusion, this study found that although coaches perceptions, for the most part, matched what took place on the field, there were instances where we saw the opposite action take place. This has important practical implications for coaching and practice. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-10-14
Health Expenditure and Economic Performance in Selected Southern African Development Community (SADC) Countries
- Authors: Qoko, Alungile
- Date: 2022-00
- Subjects: Expenditure and economic performance
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/10235 , vital:74951
- Description: The study examined the relationship between health expenditure and economic performance in 14 Southern African Development Community (SADC) countries using annual panel data for the period of 15 years (2005-2019). Economic performance was the dependent variable with gross domestic product (GDP) per capita used as the proxy for economic performance. The other determinants of economic performance used in this study include labour force participation rate, institutional quality, and trade openness. All variables were examined logged to eliminate possibility of outliers. To test for stationarity of the series, the study employed two panel unit root tests which are the Levin, Lien and Chu (2002) commonly known as LLC, and also Im, Pesaran and Shin (2003) popularly known as IPS. The finding revealed that the series were integrated of different orders including I(0) and I(1) but not I(2). To test for a long-run relationship, Pedroni and Kao panel cointegration tests were carried out. The findings revealed there was cointegration. Based on these findings, panel auto regressive sistributed lag (ARDL), using Pooled Mean Group analysis as the best estimator for the model, was chosen to test for both long-run and short-run relationships. The empirical findings showed that there was a negative and significant relationship between health expenditure and economic performance in the 14 selected SADC countries. Governments in the SADC region should enact and enforce laws that deal with leakages in the health sector to ensure that health expenditure improves economic performance. , Thesis (Masters) -- Faculty of Economics and Finacial Sciences, 2022
- Full Text:
- Date Issued: 2022-00
- Authors: Qoko, Alungile
- Date: 2022-00
- Subjects: Expenditure and economic performance
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/10235 , vital:74951
- Description: The study examined the relationship between health expenditure and economic performance in 14 Southern African Development Community (SADC) countries using annual panel data for the period of 15 years (2005-2019). Economic performance was the dependent variable with gross domestic product (GDP) per capita used as the proxy for economic performance. The other determinants of economic performance used in this study include labour force participation rate, institutional quality, and trade openness. All variables were examined logged to eliminate possibility of outliers. To test for stationarity of the series, the study employed two panel unit root tests which are the Levin, Lien and Chu (2002) commonly known as LLC, and also Im, Pesaran and Shin (2003) popularly known as IPS. The finding revealed that the series were integrated of different orders including I(0) and I(1) but not I(2). To test for a long-run relationship, Pedroni and Kao panel cointegration tests were carried out. The findings revealed there was cointegration. Based on these findings, panel auto regressive sistributed lag (ARDL), using Pooled Mean Group analysis as the best estimator for the model, was chosen to test for both long-run and short-run relationships. The empirical findings showed that there was a negative and significant relationship between health expenditure and economic performance in the 14 selected SADC countries. Governments in the SADC region should enact and enforce laws that deal with leakages in the health sector to ensure that health expenditure improves economic performance. , Thesis (Masters) -- Faculty of Economics and Finacial Sciences, 2022
- Full Text:
- Date Issued: 2022-00
Chemical composition and in vitro ruminal degradation of diets containing Vachellia karro leaf meal and their effect on physiological responses of indigenous Xhosa lop-eared goats
- Authors: Mfisi, Khanyisa
- Date: 2021-09
- Subjects: Ruminants--Feeding and feeds , Animal nutrition
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20719 , vital:46460
- Description: The objective of this study was to determine the chemical composition and in vitro ruminal dry matter degradation (DMD) of Vachellia karro leaf meal-containing diets and their effect on feed intake and physiological responses of indigenous Xhosa lop-eared goats. Experimental diets containing 0 percent (Treatment 1), 15 percent (Treatment 2) and 30 percent (Treatment 3) Vachellia karroo leaf meal were mixed with grass hay and crushed maize. Samples of each diet were analysed for chemical composition and in vitro ruminal DM degradability. A total of 18 eight-month-old indigenous Xhosa lop-eared goats, initially weighing 20.81 ± 1.83 kg were randomly assigned to each diet in a Completely Randomized Design. The goats were confined in individual well-ventilated roofed pens and each dietary treatment had a total of 6 goats. The feed was offered at a rate of 3 percent of live weight twice a day, at 08:00 in the morning and at 16:00 in the afternoon. The experimental feeding trial lasted for 80 days, where 10 days was allowed for adaptation. Goat live weight, Average daily feed intake (ADFI), and Body condition scores (BCS) were recorded weekly FAMACHA scores and fecal eggs counts were also determined weekly. Blood samples were collected via vein puncture on the last day of the feeding trial for determination of glucose, total cholesterol, albumin and blood urea. Significantly higher (P < 0.05) crude protein (CP) and condensed tannins (CT) levels were observed in Vachellia karroo containing diets., while acid detergent fibre (ADF) and neutral detergent fibre (NDF) were significantly higher (P < 0.05) in the control diet. During early hours of incubation, DMD was similar (P > 0.05) across all dietary treatments. At 12 to 72 hours, the DMD was significantly higher (P < 0.05) in Vachellia karroo containing diets except at 48 hours. Correlation between DMD and NDF, ADF and fat was only visible at 24 hours. Fibre (ADF and NDF) were negatively related to DMD, while fat was positively related. A positive correlation was observed between DMD and DM, CP and ADFI. The body weight and BCS of goats was similar (P > 0.05) in all dietary treatments (P > 0.05). The ADFI was significantly higher (P < 0.05) in Vachellia karroo supplemented goats. Faecal egg count and FAMACHA scores were significantly higher (P< 0.05) in the control group compared to the Vachellia karroo supplemented treatments; while glucose levels were significantly higher in goats supplemented with Vachellia karroo compared to non-supplemented goats. Cholesterol levels were similar (P > 0.05) across all experimental groups. Goats consuming 30 percent of Vachellia karroo leaf meal had higher (P < 0.05) creatinine levels than the non-supplemented treatment. Urea levels were significantly higher (P < 0.05) in goats fed 30 percent of Vachellia karroo leaf meal than other treatments. It was concluded that the inclusion of Vachellia karroo leaves improves diet quality, diet degradability, average daily feed intake and physiological responses. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Mfisi, Khanyisa
- Date: 2021-09
- Subjects: Ruminants--Feeding and feeds , Animal nutrition
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20719 , vital:46460
- Description: The objective of this study was to determine the chemical composition and in vitro ruminal dry matter degradation (DMD) of Vachellia karro leaf meal-containing diets and their effect on feed intake and physiological responses of indigenous Xhosa lop-eared goats. Experimental diets containing 0 percent (Treatment 1), 15 percent (Treatment 2) and 30 percent (Treatment 3) Vachellia karroo leaf meal were mixed with grass hay and crushed maize. Samples of each diet were analysed for chemical composition and in vitro ruminal DM degradability. A total of 18 eight-month-old indigenous Xhosa lop-eared goats, initially weighing 20.81 ± 1.83 kg were randomly assigned to each diet in a Completely Randomized Design. The goats were confined in individual well-ventilated roofed pens and each dietary treatment had a total of 6 goats. The feed was offered at a rate of 3 percent of live weight twice a day, at 08:00 in the morning and at 16:00 in the afternoon. The experimental feeding trial lasted for 80 days, where 10 days was allowed for adaptation. Goat live weight, Average daily feed intake (ADFI), and Body condition scores (BCS) were recorded weekly FAMACHA scores and fecal eggs counts were also determined weekly. Blood samples were collected via vein puncture on the last day of the feeding trial for determination of glucose, total cholesterol, albumin and blood urea. Significantly higher (P < 0.05) crude protein (CP) and condensed tannins (CT) levels were observed in Vachellia karroo containing diets., while acid detergent fibre (ADF) and neutral detergent fibre (NDF) were significantly higher (P < 0.05) in the control diet. During early hours of incubation, DMD was similar (P > 0.05) across all dietary treatments. At 12 to 72 hours, the DMD was significantly higher (P < 0.05) in Vachellia karroo containing diets except at 48 hours. Correlation between DMD and NDF, ADF and fat was only visible at 24 hours. Fibre (ADF and NDF) were negatively related to DMD, while fat was positively related. A positive correlation was observed between DMD and DM, CP and ADFI. The body weight and BCS of goats was similar (P > 0.05) in all dietary treatments (P > 0.05). The ADFI was significantly higher (P < 0.05) in Vachellia karroo supplemented goats. Faecal egg count and FAMACHA scores were significantly higher (P< 0.05) in the control group compared to the Vachellia karroo supplemented treatments; while glucose levels were significantly higher in goats supplemented with Vachellia karroo compared to non-supplemented goats. Cholesterol levels were similar (P > 0.05) across all experimental groups. Goats consuming 30 percent of Vachellia karroo leaf meal had higher (P < 0.05) creatinine levels than the non-supplemented treatment. Urea levels were significantly higher (P < 0.05) in goats fed 30 percent of Vachellia karroo leaf meal than other treatments. It was concluded that the inclusion of Vachellia karroo leaves improves diet quality, diet degradability, average daily feed intake and physiological responses. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-09
Antibiotics combination therapy option for the control of antimicrobial-resistant non-cholera causing Vibrio species recovered from environmental niches of Eastern Cape, South Africa
- Authors: Ayodele, Oluwakemi Victoria
- Date: 2021-04
- Subjects: Drug resistance in microorganisms , Vibrio cholerae
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20396 , vital:45661
- Description: Increased rate of antibiotic resistance (AR) poses a serious threat with a resultant notion of a possible end of the antibiotics era, making it a problem of concern to public health and a great implication on the world economy and human society. Despite many approaches developed to curb this menace, antibiotics resistance is still a challenge worldwide. This has made the use of combined therapy as one of the options in many cases. This study was conducted to assess antibiotics combination therapy as an option for the control of antimicrobial-resistant non-cholera causing Vibrio species that were recovered from the environment in the Eastern Cape, South Africa. Two hundred and twenty-eight Vibrio species were recovered from the environment in the Province, and these were deposited in the archive of AEMREG. PCR was used to identify target Vibrio species. Disc diffusion method was used to evaluate the antibiotic susceptibility profile of the confirmed isolates against 11 antibiotics commonly used against infections. MIC and MBC were determined using antibiotics (imipenem, tetracycline, and nalidixic acid) that high resistance was discovered. Checkerboard assay was used to carry out antibiotics combination assay, and the FICI was calculated. Rate of kill was also determined using ½ × MIC, 1 × MIC, and 2 × MIC concentrations of the combined antibiotics at 2 hr intervals. One hundred of the isolates were confirmed to be Vibrio parahaemolyticus, 82 were Vibrio vulnificus and 46 were Vibrio fluvialis. Twenty-two (22) percent of the Vibrio parahaemolyticus isolates showed resistance against tetracycline and their resistance against other antimicrobials is as follows; nalidixic acid (16 percent), ampicillin (14 percent), cefotaxime (14 percent), chloramphenicol (12 percent) and amikacin (11 percent). For Vibrio vulnificus, prevalence of resistance was as follows: imipenem (40 percent), tetracycline (22 percent), ampicillin (18 percent), meropenem (15 percent), and chloramphenicol (11 percent). Vibrio fluvialis showed the following resistance profile: nalidixic acid (28 percent), tetracycline (28percent), ampicillin (20 percent), chloramphenicol (15 percent), amikacin (11 percent) and cefotaxime (11 percent). About 38 multiple antibiotic resistance phenotypes (MARP) were recorded in all species that were evaluated. About 23 percent were resistant to over 3 antibiotics used. The multiple antibiotic resistant indices (MARI) ranged between 0.3 and 0.8. MIC and MBC were carried against isolates that were resistant to the two most common antibiotics tested. MIC and MBC were determined in the following order: tetracycline and nalidixic acid at concentrations ranging from 16 μg/ml to 1024 μg/ml for Vibrio parahaemolyticus and 32 μg/ml to 2048 μg/ml for Vibrio fluvialis. Also, the MIC and MBC of imipenem and tetracycline at concentrations ranging from 8 μg/ml to 256 μg/ml for Vibrio vulnificus were determined. Antibiotics combination therapy was carried out and synergistic activity was observed in 3 of the 16 resistant V. parahaemolyticus isolates, 3 of the16 resistant V. vulnificus isolates and 2 of the 13 resistant V. fluvialis isolates. Antagonism was not observed across all the drug combinations. Rate of kill was also determined and at 6 hr exposure time, the highest concentration (2 × MIC) exhibited bactericidal effect across all three Vibrio species. The result derived in this research, therefore, propose that combination therapy is a promising solution to antimicrobial resistance in Vibrio species. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Ayodele, Oluwakemi Victoria
- Date: 2021-04
- Subjects: Drug resistance in microorganisms , Vibrio cholerae
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20396 , vital:45661
- Description: Increased rate of antibiotic resistance (AR) poses a serious threat with a resultant notion of a possible end of the antibiotics era, making it a problem of concern to public health and a great implication on the world economy and human society. Despite many approaches developed to curb this menace, antibiotics resistance is still a challenge worldwide. This has made the use of combined therapy as one of the options in many cases. This study was conducted to assess antibiotics combination therapy as an option for the control of antimicrobial-resistant non-cholera causing Vibrio species that were recovered from the environment in the Eastern Cape, South Africa. Two hundred and twenty-eight Vibrio species were recovered from the environment in the Province, and these were deposited in the archive of AEMREG. PCR was used to identify target Vibrio species. Disc diffusion method was used to evaluate the antibiotic susceptibility profile of the confirmed isolates against 11 antibiotics commonly used against infections. MIC and MBC were determined using antibiotics (imipenem, tetracycline, and nalidixic acid) that high resistance was discovered. Checkerboard assay was used to carry out antibiotics combination assay, and the FICI was calculated. Rate of kill was also determined using ½ × MIC, 1 × MIC, and 2 × MIC concentrations of the combined antibiotics at 2 hr intervals. One hundred of the isolates were confirmed to be Vibrio parahaemolyticus, 82 were Vibrio vulnificus and 46 were Vibrio fluvialis. Twenty-two (22) percent of the Vibrio parahaemolyticus isolates showed resistance against tetracycline and their resistance against other antimicrobials is as follows; nalidixic acid (16 percent), ampicillin (14 percent), cefotaxime (14 percent), chloramphenicol (12 percent) and amikacin (11 percent). For Vibrio vulnificus, prevalence of resistance was as follows: imipenem (40 percent), tetracycline (22 percent), ampicillin (18 percent), meropenem (15 percent), and chloramphenicol (11 percent). Vibrio fluvialis showed the following resistance profile: nalidixic acid (28 percent), tetracycline (28percent), ampicillin (20 percent), chloramphenicol (15 percent), amikacin (11 percent) and cefotaxime (11 percent). About 38 multiple antibiotic resistance phenotypes (MARP) were recorded in all species that were evaluated. About 23 percent were resistant to over 3 antibiotics used. The multiple antibiotic resistant indices (MARI) ranged between 0.3 and 0.8. MIC and MBC were carried against isolates that were resistant to the two most common antibiotics tested. MIC and MBC were determined in the following order: tetracycline and nalidixic acid at concentrations ranging from 16 μg/ml to 1024 μg/ml for Vibrio parahaemolyticus and 32 μg/ml to 2048 μg/ml for Vibrio fluvialis. Also, the MIC and MBC of imipenem and tetracycline at concentrations ranging from 8 μg/ml to 256 μg/ml for Vibrio vulnificus were determined. Antibiotics combination therapy was carried out and synergistic activity was observed in 3 of the 16 resistant V. parahaemolyticus isolates, 3 of the16 resistant V. vulnificus isolates and 2 of the 13 resistant V. fluvialis isolates. Antagonism was not observed across all the drug combinations. Rate of kill was also determined and at 6 hr exposure time, the highest concentration (2 × MIC) exhibited bactericidal effect across all three Vibrio species. The result derived in this research, therefore, propose that combination therapy is a promising solution to antimicrobial resistance in Vibrio species. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
Impact of feeding milk once-a-day on growth and development of jersey calves
- Authors: Myburgh, Albertus Petrus
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Calves -- Feeding and feeds
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52095 , vital:43438
- Description: In conventional calf rearing systems calves are fed milk twice a day. Calves are normally housed in a calf shed, kept in individual pens or in groups. The goal should be to limit mor-talities to less than 5% from birth to 30 days. This can be achieved by reducing animal stress, controlling diseases and feeding the animals properly. The immune function can be de-pressed by inadequate nutrition which will increase susceptibility to diseases. Key objective on a dairy farm should be to rear a healthy calf until the calf reaches the optimum mating weight. Digestive disorders and respiratory diseases are the main causes of mortalities of young calves. Jersey calves at Outeniqua Research Farm are kept in movable hutches out-side, for 8 weeks and whole milk is fed only once a day. Although it is common practice to feed milk to calves twice-a-day, Jersey calves are raised with great success by feeding whole milk once-a-day, but proven data was never collected to indicate that feeding whole milk to Jersey calves does not compromise growth or development of calves. Much research was done on feeding of milk to Holstein calves, but little was done on Jersey calves. Research also shows results on feeding of milk replacer rather than whole milk. This raised the question of can whole milk be fed once-a-day successfully to Jersey calves with-out compromising growth and development and what are the advantages of feeding whole milk once-a-day to Jersey calves? , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text: false
- Date Issued: 2021-04
- Authors: Myburgh, Albertus Petrus
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Calves -- Feeding and feeds
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52095 , vital:43438
- Description: In conventional calf rearing systems calves are fed milk twice a day. Calves are normally housed in a calf shed, kept in individual pens or in groups. The goal should be to limit mor-talities to less than 5% from birth to 30 days. This can be achieved by reducing animal stress, controlling diseases and feeding the animals properly. The immune function can be de-pressed by inadequate nutrition which will increase susceptibility to diseases. Key objective on a dairy farm should be to rear a healthy calf until the calf reaches the optimum mating weight. Digestive disorders and respiratory diseases are the main causes of mortalities of young calves. Jersey calves at Outeniqua Research Farm are kept in movable hutches out-side, for 8 weeks and whole milk is fed only once a day. Although it is common practice to feed milk to calves twice-a-day, Jersey calves are raised with great success by feeding whole milk once-a-day, but proven data was never collected to indicate that feeding whole milk to Jersey calves does not compromise growth or development of calves. Much research was done on feeding of milk to Holstein calves, but little was done on Jersey calves. Research also shows results on feeding of milk replacer rather than whole milk. This raised the question of can whole milk be fed once-a-day successfully to Jersey calves with-out compromising growth and development and what are the advantages of feeding whole milk once-a-day to Jersey calves? , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text: false
- Date Issued: 2021-04
The relationship between financial development and economic growth in Eswatini (formerly Swaziland)
- Fakudze, Siphe-okuhlehttps://orcid.org/0000-0001-7928-5552
- Authors: Fakudze, Siphe-okuhlehttps://orcid.org/0000-0001-7928-5552
- Date: 2019-12
- Subjects: Economic development -- Eswatini , Eswatini -- Economic conditions
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19704 , vital:43170
- Description: The study empirically examined the relationship between financial development and economic growth in Eswatini using quarterly time series data covering the period 1996 to 2018. Auto Regressive Distributed Lag bounds test technique and Granger causality test were used. The ratio of credit to the private sector to economic growth, openness to trade, revealed a positive relationship with economic growth in the long-run and short-run dynamics. Money supply displayed a negative association with real output in the long-run and short-run. Government size as a ratio of GDP highlighted a negative linkage with economic growth in the long-run and temporary positive association in the short-run. The Granger Causality test results displayed unidirectional causality running from financial development to economic growth, supporting the demand following causality hypothesis in Eswatini. The study recommends developing policies aimed at enhancing credit to the private sector to stimulate investment; reprioritise Government expenditure to minimise fiscal gap and support supply side reforms focusing on infrastructure development; control domestic liquidity and develop market securities attractive to the private sector; strengthen trade intensity to bolster growth; and improve regulatory framework to develop the non-bank financial industry. , Thesis (MCom) -- Faculty of Management and Commerce, 2019
- Full Text:
- Date Issued: 2019-12
- Authors: Fakudze, Siphe-okuhlehttps://orcid.org/0000-0001-7928-5552
- Date: 2019-12
- Subjects: Economic development -- Eswatini , Eswatini -- Economic conditions
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19704 , vital:43170
- Description: The study empirically examined the relationship between financial development and economic growth in Eswatini using quarterly time series data covering the period 1996 to 2018. Auto Regressive Distributed Lag bounds test technique and Granger causality test were used. The ratio of credit to the private sector to economic growth, openness to trade, revealed a positive relationship with economic growth in the long-run and short-run dynamics. Money supply displayed a negative association with real output in the long-run and short-run. Government size as a ratio of GDP highlighted a negative linkage with economic growth in the long-run and temporary positive association in the short-run. The Granger Causality test results displayed unidirectional causality running from financial development to economic growth, supporting the demand following causality hypothesis in Eswatini. The study recommends developing policies aimed at enhancing credit to the private sector to stimulate investment; reprioritise Government expenditure to minimise fiscal gap and support supply side reforms focusing on infrastructure development; control domestic liquidity and develop market securities attractive to the private sector; strengthen trade intensity to bolster growth; and improve regulatory framework to develop the non-bank financial industry. , Thesis (MCom) -- Faculty of Management and Commerce, 2019
- Full Text:
- Date Issued: 2019-12
Production, purification, and characterisation of proteases from an ericoid mycorrhizal fungus, Oidiodendron maius
- Authors: Manyumwa, Colleen Varaidzo
- Date: 2018
- Subjects: Ascomycetes , Mycorrhizal fungi , Ericaceae , Proteolytic enzymes , Silver Recycling
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/62833 , vital:28298
- Description: The aim of this study was to produce, purify and characterise proteases from the ericoid mycorrhizal fungus, Oidiodendron maius (CafRU082b/KP119480), as well as to explore their potential application in the recovery of silver from X-ray film. Firstly, the growth of the ericoid mycorrhizal fungus, Oidiodendron maius (CafRU082b), was studied, and its ability to produce proteolytic enzymes was investigated. O. maius proved to grow well in the dark, submerged in Modified Melin Norkran’s liquid medium at a pH of 5 and at 25°C. Pure cultures of the fungus were maintained on Potato Dextrose Agar (PDA). The fungus grew on PDA plates containing different substrates including haemoglobin, casein, gelatin as well as azocasein. Zones of clearance, however, were only observed on plates containing gelatin after treatment with mercuric chloride, HgCl2. Proteases were successfully produced after 14 days when gelatin was incorporated into the growth medium. After production of the proteases, purification and characterisation of the enzymes was performed. Purification of the enzymes was performed by acetone precipitation followed by ultrafiltration with 50 kDa and 30 kDa cut off membrane filters. A final purification fold of approximately 37.6 was achieved. Unusual yields of above 100% were observed after each purification step with the final yield achieved being 196% with a final specific activity of 2707 U/mg. SDS-PAGE revealed a protease band of 35 kDa which was also visible on the zymogram at approximately 36 kDa. The zymogram showed clear hydrolysis bands against a blue background after staining with Coomassie Brilliant Blue. Physico-chemical characterisation of the protease revealed its pH optimum to be pH 3.0 and its temperature optimum 68°C. Another peak was observed on the pH profile at pH 7.0. The protease exhibited high thermostability at temperatures 37°C, 80°C as well as 100°C with the enzyme retaining close to 50% of its initial activity after 4 h of exposure to all three temperatures. All ions tested for their effects on the proteases, except Ca2+, enhanced protease activity. Ca2+ did not exhibit any significant effect on the enzyme’s activity while Zn2+ had the highest effect, enhancing enzyme activity by 305%. The proteases, however, were not significantly inhibited by EDTA, a metal chelating agent and a known metalloprotease inhibitor. The enzyme was classified as an aspartic protease due to complete inhibition by 25 μM of pepstatin A, coupled to its low pH optimum of 3.0. Addition of trans-Epoxysuccinyl-L-leucylamido-(4-guanidino)butane (E-64), a cysteine protease inhibitor, and 2-mercaptoethanol increased protease activity. The proteases exhibited a narrow substrate specificity towards gelatin and no other substrate. Substrate kinetics values were plotted on a Michaelis-Menten Graph and showed that the enzyme had a Vmax of 55.25 U/ml and a Km of 2.7 mg/ml gelatin. A low Km indicated that the protease had a high affinity for gelatin. Silver recovery studies from X-ray film revealed the proteases’ capability to remove silver from X-ray film, leaving the film intact. The recovery of silver was perceived visually, by film observation, as well as by scan electron microscopy (SEM) images, where clearance of the film was observed after incubation with the enzyme. Energy dispersive X-ray spectroscopy (EDS) profiles also confirmed removal of silver from the film, with a Ag peak showing on the profile of the film before treatment with the proteases and no peak after treatment. The crude protease sample was, however, catalytically more efficient compared to the partially purified sample. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2018
- Authors: Manyumwa, Colleen Varaidzo
- Date: 2018
- Subjects: Ascomycetes , Mycorrhizal fungi , Ericaceae , Proteolytic enzymes , Silver Recycling
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/62833 , vital:28298
- Description: The aim of this study was to produce, purify and characterise proteases from the ericoid mycorrhizal fungus, Oidiodendron maius (CafRU082b/KP119480), as well as to explore their potential application in the recovery of silver from X-ray film. Firstly, the growth of the ericoid mycorrhizal fungus, Oidiodendron maius (CafRU082b), was studied, and its ability to produce proteolytic enzymes was investigated. O. maius proved to grow well in the dark, submerged in Modified Melin Norkran’s liquid medium at a pH of 5 and at 25°C. Pure cultures of the fungus were maintained on Potato Dextrose Agar (PDA). The fungus grew on PDA plates containing different substrates including haemoglobin, casein, gelatin as well as azocasein. Zones of clearance, however, were only observed on plates containing gelatin after treatment with mercuric chloride, HgCl2. Proteases were successfully produced after 14 days when gelatin was incorporated into the growth medium. After production of the proteases, purification and characterisation of the enzymes was performed. Purification of the enzymes was performed by acetone precipitation followed by ultrafiltration with 50 kDa and 30 kDa cut off membrane filters. A final purification fold of approximately 37.6 was achieved. Unusual yields of above 100% were observed after each purification step with the final yield achieved being 196% with a final specific activity of 2707 U/mg. SDS-PAGE revealed a protease band of 35 kDa which was also visible on the zymogram at approximately 36 kDa. The zymogram showed clear hydrolysis bands against a blue background after staining with Coomassie Brilliant Blue. Physico-chemical characterisation of the protease revealed its pH optimum to be pH 3.0 and its temperature optimum 68°C. Another peak was observed on the pH profile at pH 7.0. The protease exhibited high thermostability at temperatures 37°C, 80°C as well as 100°C with the enzyme retaining close to 50% of its initial activity after 4 h of exposure to all three temperatures. All ions tested for their effects on the proteases, except Ca2+, enhanced protease activity. Ca2+ did not exhibit any significant effect on the enzyme’s activity while Zn2+ had the highest effect, enhancing enzyme activity by 305%. The proteases, however, were not significantly inhibited by EDTA, a metal chelating agent and a known metalloprotease inhibitor. The enzyme was classified as an aspartic protease due to complete inhibition by 25 μM of pepstatin A, coupled to its low pH optimum of 3.0. Addition of trans-Epoxysuccinyl-L-leucylamido-(4-guanidino)butane (E-64), a cysteine protease inhibitor, and 2-mercaptoethanol increased protease activity. The proteases exhibited a narrow substrate specificity towards gelatin and no other substrate. Substrate kinetics values were plotted on a Michaelis-Menten Graph and showed that the enzyme had a Vmax of 55.25 U/ml and a Km of 2.7 mg/ml gelatin. A low Km indicated that the protease had a high affinity for gelatin. Silver recovery studies from X-ray film revealed the proteases’ capability to remove silver from X-ray film, leaving the film intact. The recovery of silver was perceived visually, by film observation, as well as by scan electron microscopy (SEM) images, where clearance of the film was observed after incubation with the enzyme. Energy dispersive X-ray spectroscopy (EDS) profiles also confirmed removal of silver from the film, with a Ag peak showing on the profile of the film before treatment with the proteases and no peak after treatment. The crude protease sample was, however, catalytically more efficient compared to the partially purified sample. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Date Issued: 2018
Assessing the potential role of microorganisms in the production of seedlings for the restoration of Albany Thicket
- Authors: Mpama, Nelisa
- Date: 2017
- Subjects: Vesicular-arbuscular mycorrhizas , Rhizobacteria , Restoration ecology South Africa Albany , Microorganisms
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/64555 , vital:28558
- Description: The role of microorganisms in restoration of the Albany Thicket has not been well documented, although the benefits to plants of these various interactions has been well documented. Microorganisms are chief ecological engineers and assist in resolving environmental problems and act to restore degraded ecosystem function by forming mutual relationships with the roots of the plants. The aim of this study was to assess the potential of microorganisms for the improved biomass production of selected woody and succulent seedlings used in mesic thicket restoration. Three tree species were selected for propagation in this study namely; Mystroxylon aethiopicum Scutia myrtina and Aloe ferox. Soil samples were collected from a degraded and intact thicket site from Bathurst, South Africa. Soils were evaluated for number of arbuscular mycorrhizal (AM) spores, mycorrhizal infectivity potential and nutrient availability both before and after seedling propagation. Pasteurized soil from the degraded site was used in a pot trial. Ten replicates seedling for plant species were planted and subjected to four treatments which included inoculation with AM fungi and the rhizobacterium, Enterobacter sp., alone and in combination; the fourth treatment was an un-inouclated control. Plant growth parameters were recorded at regular intervals where appropriate and seedlings were harvested after 24 weeks for biomass measurements and AM colonisation assessments. Although generally low (< 1 spore per gram) the density of AM fungal spores was significantly higher in soils from the intact site when compared with soils from the degraded site. The mycorrhizal potential of the soils was however not significantly different. Mystroxylon aethiopicum seedling shoot height, canopy diameter and shoot biomass showed a significant increase when inoculated with AM fungi while S. myrtina seedlings showed increased shoot height when inoculated with both AM fungi and Enterobacter sp. Aloe ferox seedlings did not respond to microbial inoculation. The concentration of soil P and Na increased in treatments with Enterobacter sp. alone and in combination with AM fungi. Mystroxylon aethiopicum and S. myrtina seedlings showed a dependency on microbial inoculants indicating the importance of inoculation in the nursery before planting out into the field. Overall AM fungal inoculants applied to seedlings can be used to compensate for nutrient deficiency in soils. Although the Enterobacter isolate used was known to have various plant growth promoting capabilities. It is recommended that other rhizobacterial isolates be investigated. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2017
- Full Text:
- Date Issued: 2017
- Authors: Mpama, Nelisa
- Date: 2017
- Subjects: Vesicular-arbuscular mycorrhizas , Rhizobacteria , Restoration ecology South Africa Albany , Microorganisms
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/64555 , vital:28558
- Description: The role of microorganisms in restoration of the Albany Thicket has not been well documented, although the benefits to plants of these various interactions has been well documented. Microorganisms are chief ecological engineers and assist in resolving environmental problems and act to restore degraded ecosystem function by forming mutual relationships with the roots of the plants. The aim of this study was to assess the potential of microorganisms for the improved biomass production of selected woody and succulent seedlings used in mesic thicket restoration. Three tree species were selected for propagation in this study namely; Mystroxylon aethiopicum Scutia myrtina and Aloe ferox. Soil samples were collected from a degraded and intact thicket site from Bathurst, South Africa. Soils were evaluated for number of arbuscular mycorrhizal (AM) spores, mycorrhizal infectivity potential and nutrient availability both before and after seedling propagation. Pasteurized soil from the degraded site was used in a pot trial. Ten replicates seedling for plant species were planted and subjected to four treatments which included inoculation with AM fungi and the rhizobacterium, Enterobacter sp., alone and in combination; the fourth treatment was an un-inouclated control. Plant growth parameters were recorded at regular intervals where appropriate and seedlings were harvested after 24 weeks for biomass measurements and AM colonisation assessments. Although generally low (< 1 spore per gram) the density of AM fungal spores was significantly higher in soils from the intact site when compared with soils from the degraded site. The mycorrhizal potential of the soils was however not significantly different. Mystroxylon aethiopicum seedling shoot height, canopy diameter and shoot biomass showed a significant increase when inoculated with AM fungi while S. myrtina seedlings showed increased shoot height when inoculated with both AM fungi and Enterobacter sp. Aloe ferox seedlings did not respond to microbial inoculation. The concentration of soil P and Na increased in treatments with Enterobacter sp. alone and in combination with AM fungi. Mystroxylon aethiopicum and S. myrtina seedlings showed a dependency on microbial inoculants indicating the importance of inoculation in the nursery before planting out into the field. Overall AM fungal inoculants applied to seedlings can be used to compensate for nutrient deficiency in soils. Although the Enterobacter isolate used was known to have various plant growth promoting capabilities. It is recommended that other rhizobacterial isolates be investigated. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2017
- Full Text:
- Date Issued: 2017
Synthesis, characterisation and evaluation of benzoxaborole-based hybrids as antiplasmodial agents
- Authors: Gumbo, Maureen
- Date: 2017
- Subjects: Malaria Chemotherapy , Antimalarials , Boron compounds , Drug resistance , Plasmodium falciparum , Drug development
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59193 , vital:27456
- Description: Malaria is a mosquito-borne disease, which continues to pose a threat to the entire humanity. About 40% of the world population is estimated to be at risk of infections by malaria. Despite efforts undertaken by scientific community, government entities and international organizations, malaria is still rampant. The major problem is drug resistance, where the Plasmodium spp have over the past decades developed drug resistance against available drugs. In order to counter this problem, novel antimalarial drugs that are efficacious and with novel mode of action are of great necessity. Benzoxaborole derivatives have been shown to exhibit promising antimalarial activity against Plasmodium falciparum strains. Previous studies reported on the compounds such as 6-(2- (alkoxycarbonyl)pyrazinyl-5-oxy)-1,3-dihydro-1-hydroxy-2,1-benzoxaboroles, which showed good antimalarial activity against both W7 and 3D7 strains without significant toxicity. On the other hand, chloroquine (CQ) and cinnamic acids have a wide variety of biological activity including antimalarial activity. Herein, a hybridisation strategy was employed to synthesise new CQ-benzoxaborole and cinnamoyl-benzoxaborole hybrids. CQ-Benzoxaborole 2.12a-c and cinnamoylbenzoxaborole 2.11a-g hydrid molecules were synthesised in low to good yields. Their structural identities were confirmed using conventional spectroscopic techniques (1H and 13C NMR, and mass spectrometry). CQ-benzoxaborole compounds, however, showed instability, and only 2.12b was used for in vitro biological assay and showed activity comparable to CQ. Furthermore, in vitro biological assay revealed that compounds 2.11a-g poorly inhibited the growth of P. falciparum parasites. Interestingly, these compounds, however, exhibited satisfactory activity against Trypanosoma brucei with IC50 = 0.052 μM for compound 2.11g. The cell cytotoxicity assay of all final compounds confirmed that all CQ-benzoxaborole 2.12b and cinnamoyl-benzoxaborole 2.11a-g hybrids were non-toxic against HeLa cell lines. However, efforts to further expand the structure-activity relationship (SAR) of CQbenzoxaborole by increasing the length of the linker with one extra carbon (Scheme 2.10) were not possible as an important precursor 6-formylbenzoxaborole 2.29 could not be synthesized in sufficient yields. , Thesis (MSc) -- Faculty of Faculty of Science, Chemistry, 2017
- Full Text:
- Date Issued: 2017
- Authors: Gumbo, Maureen
- Date: 2017
- Subjects: Malaria Chemotherapy , Antimalarials , Boron compounds , Drug resistance , Plasmodium falciparum , Drug development
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59193 , vital:27456
- Description: Malaria is a mosquito-borne disease, which continues to pose a threat to the entire humanity. About 40% of the world population is estimated to be at risk of infections by malaria. Despite efforts undertaken by scientific community, government entities and international organizations, malaria is still rampant. The major problem is drug resistance, where the Plasmodium spp have over the past decades developed drug resistance against available drugs. In order to counter this problem, novel antimalarial drugs that are efficacious and with novel mode of action are of great necessity. Benzoxaborole derivatives have been shown to exhibit promising antimalarial activity against Plasmodium falciparum strains. Previous studies reported on the compounds such as 6-(2- (alkoxycarbonyl)pyrazinyl-5-oxy)-1,3-dihydro-1-hydroxy-2,1-benzoxaboroles, which showed good antimalarial activity against both W7 and 3D7 strains without significant toxicity. On the other hand, chloroquine (CQ) and cinnamic acids have a wide variety of biological activity including antimalarial activity. Herein, a hybridisation strategy was employed to synthesise new CQ-benzoxaborole and cinnamoyl-benzoxaborole hybrids. CQ-Benzoxaborole 2.12a-c and cinnamoylbenzoxaborole 2.11a-g hydrid molecules were synthesised in low to good yields. Their structural identities were confirmed using conventional spectroscopic techniques (1H and 13C NMR, and mass spectrometry). CQ-benzoxaborole compounds, however, showed instability, and only 2.12b was used for in vitro biological assay and showed activity comparable to CQ. Furthermore, in vitro biological assay revealed that compounds 2.11a-g poorly inhibited the growth of P. falciparum parasites. Interestingly, these compounds, however, exhibited satisfactory activity against Trypanosoma brucei with IC50 = 0.052 μM for compound 2.11g. The cell cytotoxicity assay of all final compounds confirmed that all CQ-benzoxaborole 2.12b and cinnamoyl-benzoxaborole 2.11a-g hybrids were non-toxic against HeLa cell lines. However, efforts to further expand the structure-activity relationship (SAR) of CQbenzoxaborole by increasing the length of the linker with one extra carbon (Scheme 2.10) were not possible as an important precursor 6-formylbenzoxaborole 2.29 could not be synthesized in sufficient yields. , Thesis (MSc) -- Faculty of Faculty of Science, Chemistry, 2017
- Full Text:
- Date Issued: 2017
An investigation into the biological treatment of platinum refinery effluent using the plant Azolla Filiculoides
- Authors: Marran, Vernon Edward
- Date: 2003
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193453 , vital:45333
- Description: In order to understand the effects of metals contained in effluent and to define effluent quality suitable for safe discharge to natural water streams, it is essential to understand the effects of the interaction of metal ions with plants. The availability of metal ions and their ability to bind to plants are dependent on the chemical speciation of metals and on the biological factors governing the availability of metals within the plant cells. This thesis will address both aspects and thereby propose a combination of an appropriate chemical and biological approach to the investigation of bioaccumulation of the plant Azolla Filiculoides. Laboratory studies have shown that varying concentrations of free metal ions in solution determine efficiency of metal uptake and that metal toxicity can also be detrimental to plant life and efficiency of metal recovery from solution. Many questions however, remain unanswered with regard to the application of a biological treatment for effluent discharge. This thesis includes the determination of metal speciation combined with the study of bioaccumulation of metals in plants and their effects from test- work utilising effluent generated from a Precious Metals Refinery (PMR). Plant species are known to differ widely in their tolerance to metals, however despite an abundant knowledge on molecular, biochemical and physiological effects of metals to plants, only a few general principles have been proposed to guide the prediction of tolerance differences. The properties of protective cellular responses as well as of the molecular target sites are important components in determining the intrinsic tolerance of a particular species to a metal. The role of the whole assembly of cellular ligands in buffering metal ions within the cells will be evaluated. Standard preparation methods combined with use of Inductively Coupled Plasma Emission Spectrophotometer (1CP) used for analytical analysis will be included to reflect analytical data in providing evidence to support a conclusion. The outcome of the test work utilising the aquatic plant Azoila has proven that it can be used as a process step to re-mediate effluent generated from Precious Metal Refining operations. This process offers an alternative to the classical chemical methods widely used in the Precious Metals Refining industry proving economically viable and ensuring environmental sustainability in comparison to the current known methods of effluent treatment. , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology and Biotechnology, 2003
- Full Text:
- Date Issued: 2003
- Authors: Marran, Vernon Edward
- Date: 2003
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193453 , vital:45333
- Description: In order to understand the effects of metals contained in effluent and to define effluent quality suitable for safe discharge to natural water streams, it is essential to understand the effects of the interaction of metal ions with plants. The availability of metal ions and their ability to bind to plants are dependent on the chemical speciation of metals and on the biological factors governing the availability of metals within the plant cells. This thesis will address both aspects and thereby propose a combination of an appropriate chemical and biological approach to the investigation of bioaccumulation of the plant Azolla Filiculoides. Laboratory studies have shown that varying concentrations of free metal ions in solution determine efficiency of metal uptake and that metal toxicity can also be detrimental to plant life and efficiency of metal recovery from solution. Many questions however, remain unanswered with regard to the application of a biological treatment for effluent discharge. This thesis includes the determination of metal speciation combined with the study of bioaccumulation of metals in plants and their effects from test- work utilising effluent generated from a Precious Metals Refinery (PMR). Plant species are known to differ widely in their tolerance to metals, however despite an abundant knowledge on molecular, biochemical and physiological effects of metals to plants, only a few general principles have been proposed to guide the prediction of tolerance differences. The properties of protective cellular responses as well as of the molecular target sites are important components in determining the intrinsic tolerance of a particular species to a metal. The role of the whole assembly of cellular ligands in buffering metal ions within the cells will be evaluated. Standard preparation methods combined with use of Inductively Coupled Plasma Emission Spectrophotometer (1CP) used for analytical analysis will be included to reflect analytical data in providing evidence to support a conclusion. The outcome of the test work utilising the aquatic plant Azoila has proven that it can be used as a process step to re-mediate effluent generated from Precious Metal Refining operations. This process offers an alternative to the classical chemical methods widely used in the Precious Metals Refining industry proving economically viable and ensuring environmental sustainability in comparison to the current known methods of effluent treatment. , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology and Biotechnology, 2003
- Full Text:
- Date Issued: 2003
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