A skin that took them through
- Authors: Kgame, Mbali
- Date: 2020
- Subjects: South African fiction (English) -- 21st century , African fiction (English) -- History and criticism , Short stories, South African (English) -- 21st century , Diaries -- Authorship
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/147638 , vital:38656
- Description: This project comprises of interlinked fictional short stories capturing experiences of the “invisibilised’’ young people- the street kids, drug addicts, cashiers, childminders, the sick, first graduates etc. These stories are a way to interrogate the fallacy of a “free and fair” South Africa by noting events taking place within homes, communities and countrywide. Told in a playful, innocent, curious, childlike voice and reasoning, my work draws inspiration from Werewere Likings ‘The Amputated Memory,’ for its ability to narrate the current without divorcing the past. I draw inspiration from Liking’s way of writing family connectivity and employing an emerging voice of the narrator starting from being a child scribbling to later becoming an elder. Nana Kwame Adjei-Brenyah’s ‘Black Friday’ for scanning into young black people’s experiences in a society where their bodies move as misfits. My work also draws from Lesley Nneka Arimah’s ‘What It Means When a Man Falls from the Sky’ for the interlinked stories. Lastly the stories in this project take from Sindiwe Magona’s Mother to Mother for humanising bodies that have been reduced to frames.
- Full Text:
- Date Issued: 2020
- Authors: Kgame, Mbali
- Date: 2020
- Subjects: South African fiction (English) -- 21st century , African fiction (English) -- History and criticism , Short stories, South African (English) -- 21st century , Diaries -- Authorship
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/147638 , vital:38656
- Description: This project comprises of interlinked fictional short stories capturing experiences of the “invisibilised’’ young people- the street kids, drug addicts, cashiers, childminders, the sick, first graduates etc. These stories are a way to interrogate the fallacy of a “free and fair” South Africa by noting events taking place within homes, communities and countrywide. Told in a playful, innocent, curious, childlike voice and reasoning, my work draws inspiration from Werewere Likings ‘The Amputated Memory,’ for its ability to narrate the current without divorcing the past. I draw inspiration from Liking’s way of writing family connectivity and employing an emerging voice of the narrator starting from being a child scribbling to later becoming an elder. Nana Kwame Adjei-Brenyah’s ‘Black Friday’ for scanning into young black people’s experiences in a society where their bodies move as misfits. My work also draws from Lesley Nneka Arimah’s ‘What It Means When a Man Falls from the Sky’ for the interlinked stories. Lastly the stories in this project take from Sindiwe Magona’s Mother to Mother for humanising bodies that have been reduced to frames.
- Full Text:
- Date Issued: 2020
Economic evaluation of chemical and biological control methods on four aquatic weeds in South Africa
- Authors: Maluleke, Mary
- Date: 2020
- Subjects: Invasive plants -- Biological control -- Economic aspects -- South Africa , Introduced organisms -- Biological control -- Economic aspects -- South Africa , Aquatic weeds -- Biological control -- Economic aspects -- South Africa , Aquatic weeds -- Control -- Economic aspects -- South Africa , Aquatic resources -- Management , Cost effectiveness , Net present value , Herbicides -- Cost effectiveness , Working for Water Programme , Water conservation -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/145953 , vital:38481
- Description: Invasive alien plants (IAPs) of various kinds pose a threat to ecosystems, biodiversity, conservation and overall economy. In a world experiencing exponential increase in IAPs – this issue has become endemic, especially for developing countries such as South Africa. South Africa is a water scarce country and IAPs increase water stress. Thus, South Africa must invest in a more realistic, environmentally and economically inclusive policy outlook on the management of IAPs including aquatic weeds. This is especially urgent when considering the changing global climate, which is predicted to further reduce the quantity and quality of potable water. The Working for Water Programme (WfW) in South Africa aimed at addressing the issue of IAPs in a way that protects the environment as well as produces maximum return to society through poverty alleviation. As such, the aquatic weeds management strategy put in place for four of South Africa’s aquatic weeds Pista stratiotes, Salvinia molesta, Azolla filiculoides and Myriophyllum aquaticum - should be one that is cost-effective, efficient and sustainable; yielding the best possible return on investment. Since these four weeds are already under complete biological control, in the absence of biological agents, the WfW programme would have used herbicides to control these weeds. As such, this thesis conducted a retrospective analysis of the relative herbicide cost-saving associated with the use of biological control. To do this, due to existing limitations, E. crassipes was used as a surrogate weed and its herbicide control costs were used as proxy for the herbicide control cost estimates of the four selected weeds; with reasonable conversion factors applied to cater for the biological difference of the five weeds. Using the cost benefit analysis (CBA) framework, the net present cost (NPC) of each control method was calculated to which the relative cost-saving was considered to represent the avoided cost of using biological control instead of chemical control on these weeds. The avoided cost was used as the main benefit component when deriving the relative benefit cost ratios (BCR). Two scenarios were used, one assuming no follow-up requirement and the other assuming one follow-up requirement for chemical control. Using an 8% discount rate, the study found that the estimated cost of the biological control method on all four aquatic weeds was about R7,843,205 while for chemical control the estimated costs would have costed R149,580,142, R268,264,838 and R881,711,738 for application by means of a boat, bakkie and knapsack. Chemical control cost estimates would have increased to about R164,538,052, R295,216,120 and R1,008,761,000 for boat, bakkie and knapsack approach respectively when including a possible follow-up programme. These would have led to positive BCRs of 90.24:1, 164.97:1 and 557.99:1 across the three chemical control approaches without a follow-up (with BCR of about 99.67:1, 182.00:1 and 631.56:1 for the boat, bakkie and knapsack approach respectively with the accepted follow-up programme). When running a sensitivity test with varying discount rates of 5% and 10%, these results remained robust. As such, failing to reject the dominant hypothesis in literature, the main conclusion of the study is that biological control is indeed the more cost-effective management option compared to chemical control with respect to herbicide cost-saving. Further, biological control is most-likely to produce more environmental cost-saving and water-saving over chemical control. The study recommends the continued use of the biological control investment on the four aquatic weeds under study as well as on emerging aquatic weeds such as Iris pseudacorus, Nymphaea mexicana and Sagittaria platyphylla in South Africa.
- Full Text:
- Date Issued: 2020
Economic evaluation of chemical and biological control methods on four aquatic weeds in South Africa
- Authors: Maluleke, Mary
- Date: 2020
- Subjects: Invasive plants -- Biological control -- Economic aspects -- South Africa , Introduced organisms -- Biological control -- Economic aspects -- South Africa , Aquatic weeds -- Biological control -- Economic aspects -- South Africa , Aquatic weeds -- Control -- Economic aspects -- South Africa , Aquatic resources -- Management , Cost effectiveness , Net present value , Herbicides -- Cost effectiveness , Working for Water Programme , Water conservation -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/145953 , vital:38481
- Description: Invasive alien plants (IAPs) of various kinds pose a threat to ecosystems, biodiversity, conservation and overall economy. In a world experiencing exponential increase in IAPs – this issue has become endemic, especially for developing countries such as South Africa. South Africa is a water scarce country and IAPs increase water stress. Thus, South Africa must invest in a more realistic, environmentally and economically inclusive policy outlook on the management of IAPs including aquatic weeds. This is especially urgent when considering the changing global climate, which is predicted to further reduce the quantity and quality of potable water. The Working for Water Programme (WfW) in South Africa aimed at addressing the issue of IAPs in a way that protects the environment as well as produces maximum return to society through poverty alleviation. As such, the aquatic weeds management strategy put in place for four of South Africa’s aquatic weeds Pista stratiotes, Salvinia molesta, Azolla filiculoides and Myriophyllum aquaticum - should be one that is cost-effective, efficient and sustainable; yielding the best possible return on investment. Since these four weeds are already under complete biological control, in the absence of biological agents, the WfW programme would have used herbicides to control these weeds. As such, this thesis conducted a retrospective analysis of the relative herbicide cost-saving associated with the use of biological control. To do this, due to existing limitations, E. crassipes was used as a surrogate weed and its herbicide control costs were used as proxy for the herbicide control cost estimates of the four selected weeds; with reasonable conversion factors applied to cater for the biological difference of the five weeds. Using the cost benefit analysis (CBA) framework, the net present cost (NPC) of each control method was calculated to which the relative cost-saving was considered to represent the avoided cost of using biological control instead of chemical control on these weeds. The avoided cost was used as the main benefit component when deriving the relative benefit cost ratios (BCR). Two scenarios were used, one assuming no follow-up requirement and the other assuming one follow-up requirement for chemical control. Using an 8% discount rate, the study found that the estimated cost of the biological control method on all four aquatic weeds was about R7,843,205 while for chemical control the estimated costs would have costed R149,580,142, R268,264,838 and R881,711,738 for application by means of a boat, bakkie and knapsack. Chemical control cost estimates would have increased to about R164,538,052, R295,216,120 and R1,008,761,000 for boat, bakkie and knapsack approach respectively when including a possible follow-up programme. These would have led to positive BCRs of 90.24:1, 164.97:1 and 557.99:1 across the three chemical control approaches without a follow-up (with BCR of about 99.67:1, 182.00:1 and 631.56:1 for the boat, bakkie and knapsack approach respectively with the accepted follow-up programme). When running a sensitivity test with varying discount rates of 5% and 10%, these results remained robust. As such, failing to reject the dominant hypothesis in literature, the main conclusion of the study is that biological control is indeed the more cost-effective management option compared to chemical control with respect to herbicide cost-saving. Further, biological control is most-likely to produce more environmental cost-saving and water-saving over chemical control. The study recommends the continued use of the biological control investment on the four aquatic weeds under study as well as on emerging aquatic weeds such as Iris pseudacorus, Nymphaea mexicana and Sagittaria platyphylla in South Africa.
- Full Text:
- Date Issued: 2020
Either way you die: a collection of short stories
- Authors: Sithole, Sipho
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145081 , vital:38406
- Description: Part A: Thesis (Creative Work); Part B: Portfolio.
- Full Text:
- Date Issued: 2020
- Authors: Sithole, Sipho
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145081 , vital:38406
- Description: Part A: Thesis (Creative Work); Part B: Portfolio.
- Full Text:
- Date Issued: 2020
Explored Vygotsky’s concept of mediation in a biliteracy project in the foundation phase of a township school
- Authors: Frans, Nompumelelo Grace
- Date: 2020
- Subjects: Literacy -- South Africa -- Case studies , Education, Elementary -- South Africa -- Case studies , Education, Bilingual -- South Africa -- Case studies , Vygotskiĭ, L S (Lev Semenovich), 1896-1934 , Biliteracy Project (South Africa)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/147204 , vital:38602
- Description: The research reported on in this thesis explored teacher mediation when a biliteracy approach through task-based teaching and learning is used in a Foundation Phase classroom in a township school in the Eastern Cape. It is an action research aimed at understanding and systematically investigating how and what it means to work with bilingual mediation to ensure cognition, with emphasis on task design, facilitation for cognition, mediation forms and language use. This thesis was motivated by three issues that are still not being adequately addressed: the low level of cognitive work in South African schools, the failure to use the home languages of children throughout schooling as a medium of instruction and assessment (while providing excellent access to English as subject), and a top-down approach to both policy development and teacher professionalisation. These three issues drove me to explore theories that can help address them, and that is how I came to rely mostly on mediation, biliteracy and a task-based approach to teaching. For this research, on data handling I prepared and taught six lessons, but only three of the six lessons were recorded, transcribed and analysed for empirical data. I chose data handling, as in my previous experience I found it to include all the mathematical problem-solving skills which involve addition subtraction, analysing and comparing information. It also offered opportunities for language use, and meaningful interactive co-construction and acquiring of knowledge in the process of teaching and learning. This turned into a form of theory-driven action research, which was also developmental. I was critically reflective on my practices, and my facilitation for cognition and how I use language to make cognition possible. I also looked at the types of activities that I gave learners to help reach maximum development. The data collected from the classroom interactions, shows how I, in some instances, would take decisions, implement them and then find them not to be effective. It also shows some of the challenges I came across, from myself and the learners. Learners challenges were, unfamiliarity with the systematic build-up of data handling, filling in tables, transferring information from one form into a different form, and constructing and analysing bar graphs. This was part of pedagogynot the policy, which indicated inadequate teacher development. This could be because data handling is allocated minimal weighting from the CAPS document, and teachers do not go as in depth as they need to in dealing with data handling. My challenge was to prepare the grade 3 class for more data handling encounters in the higher grades. I had to ensure they grasped data handling concepts in their mother tongue before the switch to English as LoLT, as prescribed by policy. Learners proved to have little or no knowledge with regards to data handling concepts, which meant I had to start from the basics, as I had nothing to build on, and then progress to grade 3 level in one year. This study suggests that for any concept that has to be taught, cognition must be a priority, and strategies on how to facilitate that needs to be well thought out. Teachers need to be aware of theories that can positively impact on their practices. Teacher development is key to improvement of education, especially in the Eastern Cape. That cannot be done in isolation, but in partnership with relevant stakeholders.
- Full Text:
- Date Issued: 2020
- Authors: Frans, Nompumelelo Grace
- Date: 2020
- Subjects: Literacy -- South Africa -- Case studies , Education, Elementary -- South Africa -- Case studies , Education, Bilingual -- South Africa -- Case studies , Vygotskiĭ, L S (Lev Semenovich), 1896-1934 , Biliteracy Project (South Africa)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/147204 , vital:38602
- Description: The research reported on in this thesis explored teacher mediation when a biliteracy approach through task-based teaching and learning is used in a Foundation Phase classroom in a township school in the Eastern Cape. It is an action research aimed at understanding and systematically investigating how and what it means to work with bilingual mediation to ensure cognition, with emphasis on task design, facilitation for cognition, mediation forms and language use. This thesis was motivated by three issues that are still not being adequately addressed: the low level of cognitive work in South African schools, the failure to use the home languages of children throughout schooling as a medium of instruction and assessment (while providing excellent access to English as subject), and a top-down approach to both policy development and teacher professionalisation. These three issues drove me to explore theories that can help address them, and that is how I came to rely mostly on mediation, biliteracy and a task-based approach to teaching. For this research, on data handling I prepared and taught six lessons, but only three of the six lessons were recorded, transcribed and analysed for empirical data. I chose data handling, as in my previous experience I found it to include all the mathematical problem-solving skills which involve addition subtraction, analysing and comparing information. It also offered opportunities for language use, and meaningful interactive co-construction and acquiring of knowledge in the process of teaching and learning. This turned into a form of theory-driven action research, which was also developmental. I was critically reflective on my practices, and my facilitation for cognition and how I use language to make cognition possible. I also looked at the types of activities that I gave learners to help reach maximum development. The data collected from the classroom interactions, shows how I, in some instances, would take decisions, implement them and then find them not to be effective. It also shows some of the challenges I came across, from myself and the learners. Learners challenges were, unfamiliarity with the systematic build-up of data handling, filling in tables, transferring information from one form into a different form, and constructing and analysing bar graphs. This was part of pedagogynot the policy, which indicated inadequate teacher development. This could be because data handling is allocated minimal weighting from the CAPS document, and teachers do not go as in depth as they need to in dealing with data handling. My challenge was to prepare the grade 3 class for more data handling encounters in the higher grades. I had to ensure they grasped data handling concepts in their mother tongue before the switch to English as LoLT, as prescribed by policy. Learners proved to have little or no knowledge with regards to data handling concepts, which meant I had to start from the basics, as I had nothing to build on, and then progress to grade 3 level in one year. This study suggests that for any concept that has to be taught, cognition must be a priority, and strategies on how to facilitate that needs to be well thought out. Teachers need to be aware of theories that can positively impact on their practices. Teacher development is key to improvement of education, especially in the Eastern Cape. That cannot be done in isolation, but in partnership with relevant stakeholders.
- Full Text:
- Date Issued: 2020
Modelling and investigating primary beam effects of reflector antenna arrays
- Authors: Iheanetu, Kelachukwu
- Date: 2020
- Subjects: Antennas, Reflector , Radio telescopes , Astronomical instruments -- Calibration , Holography , Polynomials , Very large array telescopes -- South Africa , Astronomy -- Data processing , Primary beam effects , Jacobi-Bessel pattern , Cassbeam software , MeerKAT telescope
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/147425 , vital:38635
- Description: Signals received by a radio telescope are always affected by propagation and instrumental effects. These effects need to be modelled and accounted for during the process of calibration. The primary beam (PB) of the antenna is one major instrumental effect that needs to be accounted for during calibration. Producing accurate models of the radio antenna PB is crucial, and many approaches (like electromagnetic and optical simulations) have been used to model it. The cos³ function, Jacobi-Bessel pattern, characteristic basis function patterns (CBFP) and Cassbeam software (which uses optical ray-tracing with antenna parameters) have also been used to model it. These models capture the basic PB effects. Real-life PB patterns differ from these models due to various subtle effects such as mechanical deformation and effects introduced into the PB due to standing waves that exist in reflector antennas. The actual patterns can be measured via a process called astro-holography (or holography), but this is subject to noise, radio frequency interference, and other measurement errors. In our approach, we use principal component analysis and Zernike polynomials to model the PBs of the Very Large Array (VLA) and the MeerKAT telescopes from their holography measured data. The models have reconstruction errors of less than 5% at a compression factor of approximately 98% for both arrays. We also present steps that can be used to generate accurate beam models for any telescope (independent of its design) based on holography measured data. Analysis of the VLA measured PBs revealed that the graph of the beam sizes (and centre offset positions) have a fast oscillating trend (superimposed on a slow trend) with frequency. This spectral behaviour we termed ripple or characteristic effects. Most existing PB models that are used in calibrating VLA data do not incorporate these direction dependent effects (DDEs). We investigate the impact of using PB models that ignore this DDE in continuum calibration and imaging via simulations. Our experiments show that, although these effects translate into less than 10% errors in source flux recovery, they do lead to 30% reduction in the dynamic range. To prepare data for Hi and radio halo (faint emissions) science analysis requires carrying out foreground subtraction of bright (continuum) sources. We investigate the impact of using beam models that ignore these ripple effects during continuum subtraction. These show that using PB models which completely ignore the ripple effects in continuum subtraction could translate to error of more to 30% in the recovered Hi spectral properties. This implies that science inferences drawn from the results for Hi studies could have errors of the same magnitude.
- Full Text:
- Date Issued: 2020
- Authors: Iheanetu, Kelachukwu
- Date: 2020
- Subjects: Antennas, Reflector , Radio telescopes , Astronomical instruments -- Calibration , Holography , Polynomials , Very large array telescopes -- South Africa , Astronomy -- Data processing , Primary beam effects , Jacobi-Bessel pattern , Cassbeam software , MeerKAT telescope
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/147425 , vital:38635
- Description: Signals received by a radio telescope are always affected by propagation and instrumental effects. These effects need to be modelled and accounted for during the process of calibration. The primary beam (PB) of the antenna is one major instrumental effect that needs to be accounted for during calibration. Producing accurate models of the radio antenna PB is crucial, and many approaches (like electromagnetic and optical simulations) have been used to model it. The cos³ function, Jacobi-Bessel pattern, characteristic basis function patterns (CBFP) and Cassbeam software (which uses optical ray-tracing with antenna parameters) have also been used to model it. These models capture the basic PB effects. Real-life PB patterns differ from these models due to various subtle effects such as mechanical deformation and effects introduced into the PB due to standing waves that exist in reflector antennas. The actual patterns can be measured via a process called astro-holography (or holography), but this is subject to noise, radio frequency interference, and other measurement errors. In our approach, we use principal component analysis and Zernike polynomials to model the PBs of the Very Large Array (VLA) and the MeerKAT telescopes from their holography measured data. The models have reconstruction errors of less than 5% at a compression factor of approximately 98% for both arrays. We also present steps that can be used to generate accurate beam models for any telescope (independent of its design) based on holography measured data. Analysis of the VLA measured PBs revealed that the graph of the beam sizes (and centre offset positions) have a fast oscillating trend (superimposed on a slow trend) with frequency. This spectral behaviour we termed ripple or characteristic effects. Most existing PB models that are used in calibrating VLA data do not incorporate these direction dependent effects (DDEs). We investigate the impact of using PB models that ignore this DDE in continuum calibration and imaging via simulations. Our experiments show that, although these effects translate into less than 10% errors in source flux recovery, they do lead to 30% reduction in the dynamic range. To prepare data for Hi and radio halo (faint emissions) science analysis requires carrying out foreground subtraction of bright (continuum) sources. We investigate the impact of using beam models that ignore these ripple effects during continuum subtraction. These show that using PB models which completely ignore the ripple effects in continuum subtraction could translate to error of more to 30% in the recovered Hi spectral properties. This implies that science inferences drawn from the results for Hi studies could have errors of the same magnitude.
- Full Text:
- Date Issued: 2020
Sectoral co-integration and portfolio diversification benefits: a business cycle examination of South African equity sectors
- Authors: Hofisi, Tinashe S
- Date: 2020
- Subjects: Portfolio management -- South Africa , Investments -- South Africa , Investments, South African , Stocks -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/146379 , vital:38521
- Description: The onset of globalisation and simultaneous changes in financial technology and financial reforms dissipated hurdles once faced in financial transactions among stock markets. Hence, stock markets around the world became increasingly integrated because there was a free flow of cross border investments. Consequently, international diversification diminished thereby undermining the ability of investors to diversify investments across borders. For that reason, recent literature on portfolio diversification is urging investors to shift their focus to domestic portfolio diversification as an alternative. On that account, this study aims to examine the co-integration and dynamic causalities between South African equity market sectors in order to ascertain the sectoral diversification opportunities available to domestic investors over time. The study was examined over the different phases of the business cycle as well as the full sample, i.e. 2004 – 2018, with a view to shedding light on the inter-sectoral diversification opportunities of domestic investors over the South African business cycle. The phases of the business cycle applied are a| expansion and boom; b| recession and recovery phase and c| stagnation phase. The Johansen co-integration and Granger-causality tests were employed. The hypothesis of the study is that, if sectors are not cointegrated, then diversification benefits can be reaped by constructing a portfolio that combines stocks from the respective sectors. On the whole, the findings of this study show that there are both long-run and short-run diversification opportunities across the different phases of the South African business cycle as well as the full sample. However, there are lesser diversification opportunities in the recession and recovery phase over both the long-run and short-run. These results indicate that domestic sectoral portfolio diversification is least effective when it is needed the most (i.e. in a period of heightened volatility such as recession and recovery phase). This study will contribute to the existing literature in two ways; firstly, to investors who intend to diversify their portfolios domestically rather than internationally and, secondly, after reasonably thorough research it was evident that there is scant literature on domestic sectoral diversification in South Africa. As a result, the study attempts to address this gap. Additionally, the essence of the business cycle in this study is to make investors aware of potential diversification opportunities when positioning their portfolios for the next shift in the business cycle.
- Full Text:
- Date Issued: 2020
- Authors: Hofisi, Tinashe S
- Date: 2020
- Subjects: Portfolio management -- South Africa , Investments -- South Africa , Investments, South African , Stocks -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/146379 , vital:38521
- Description: The onset of globalisation and simultaneous changes in financial technology and financial reforms dissipated hurdles once faced in financial transactions among stock markets. Hence, stock markets around the world became increasingly integrated because there was a free flow of cross border investments. Consequently, international diversification diminished thereby undermining the ability of investors to diversify investments across borders. For that reason, recent literature on portfolio diversification is urging investors to shift their focus to domestic portfolio diversification as an alternative. On that account, this study aims to examine the co-integration and dynamic causalities between South African equity market sectors in order to ascertain the sectoral diversification opportunities available to domestic investors over time. The study was examined over the different phases of the business cycle as well as the full sample, i.e. 2004 – 2018, with a view to shedding light on the inter-sectoral diversification opportunities of domestic investors over the South African business cycle. The phases of the business cycle applied are a| expansion and boom; b| recession and recovery phase and c| stagnation phase. The Johansen co-integration and Granger-causality tests were employed. The hypothesis of the study is that, if sectors are not cointegrated, then diversification benefits can be reaped by constructing a portfolio that combines stocks from the respective sectors. On the whole, the findings of this study show that there are both long-run and short-run diversification opportunities across the different phases of the South African business cycle as well as the full sample. However, there are lesser diversification opportunities in the recession and recovery phase over both the long-run and short-run. These results indicate that domestic sectoral portfolio diversification is least effective when it is needed the most (i.e. in a period of heightened volatility such as recession and recovery phase). This study will contribute to the existing literature in two ways; firstly, to investors who intend to diversify their portfolios domestically rather than internationally and, secondly, after reasonably thorough research it was evident that there is scant literature on domestic sectoral diversification in South Africa. As a result, the study attempts to address this gap. Additionally, the essence of the business cycle in this study is to make investors aware of potential diversification opportunities when positioning their portfolios for the next shift in the business cycle.
- Full Text:
- Date Issued: 2020
The current nature of intra-regional trade in the proposed tripartite free trade area
- Authors: Chibuta, Chisengele
- Date: 2020
- Subjects: Customs unions -- Africa, Southern -- Economic integration , Africa, Southern -- Economic policy , Africa, Southern -- Economic integration , Africa, Southern -- Economic conditions , Tripartite Free Trade Area , Free trade -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/146744 , vital:38553
- Description: This thesis examines and analyses the current nature of intra-regional trade between member states of the proposed Tripartite Free Trade Area in order to contribute to an understanding of the potential for intra-regional trade within the region to increase. Trade Complementarity Indexes were used to determine how well the structures of the three founding blocs’ major imports and exports match. The results show that there is a high degree of trade complementarity in the trade of the top 5 major products traded between the regional groups. With the proposed TFTA in place, high trade complementarity could lead to increased trade between the regional groups. Trade Intensity Indexes were used to determine how intensively the three founding blocs trade with one another. Results from the indexes help determine the extent to which the blocs currently view each other as important trading partners and the implications of this for the proposed TFTA. Results show that EAC and SADC as well as EAC and COMESA viewed each other as significant trading partners while SADC and COMESA did not for the majority of the years from 2001 to 2018. With the TFTA in place, intra-regional trade could be strengthened among the members who currently trade intensively because tariffs between them would be progressively eliminated as required by the TFTA Agreement. Revealed Comparative Advantage Indexes were used to gain insights on whether member states have any comparative advantage in their top 5 exports. Results from the indexes were used to determine whether member states have comparative advantage in similar or dissimilar major exports and the implications of this for the proposed TFTA. Results show that member states have revealed comparative advantage in similar products and these products present opportunities for joint-production among member states as well as sectors for product development once the proposed TFTA is in place. Revealed Trade Barrier Indexes were used to gain insights into the extent of ease of market access into each regional bloc’s market. Results from the indexes indicate whether major products imported from each other receive possibly discriminatory or preferential treatment. The results indicate that the majority of the top 5 imports sourced from each region receive preferential treatment. This indicates that there is ease of market access for the top 5 imports sourced from each other and this could promote increased intra-regional trade among member states in these product categories because tariff and non-tariff barriers to trade will be progressively eliminated once the TFTA is in place.
- Full Text:
- Date Issued: 2020
- Authors: Chibuta, Chisengele
- Date: 2020
- Subjects: Customs unions -- Africa, Southern -- Economic integration , Africa, Southern -- Economic policy , Africa, Southern -- Economic integration , Africa, Southern -- Economic conditions , Tripartite Free Trade Area , Free trade -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/146744 , vital:38553
- Description: This thesis examines and analyses the current nature of intra-regional trade between member states of the proposed Tripartite Free Trade Area in order to contribute to an understanding of the potential for intra-regional trade within the region to increase. Trade Complementarity Indexes were used to determine how well the structures of the three founding blocs’ major imports and exports match. The results show that there is a high degree of trade complementarity in the trade of the top 5 major products traded between the regional groups. With the proposed TFTA in place, high trade complementarity could lead to increased trade between the regional groups. Trade Intensity Indexes were used to determine how intensively the three founding blocs trade with one another. Results from the indexes help determine the extent to which the blocs currently view each other as important trading partners and the implications of this for the proposed TFTA. Results show that EAC and SADC as well as EAC and COMESA viewed each other as significant trading partners while SADC and COMESA did not for the majority of the years from 2001 to 2018. With the TFTA in place, intra-regional trade could be strengthened among the members who currently trade intensively because tariffs between them would be progressively eliminated as required by the TFTA Agreement. Revealed Comparative Advantage Indexes were used to gain insights on whether member states have any comparative advantage in their top 5 exports. Results from the indexes were used to determine whether member states have comparative advantage in similar or dissimilar major exports and the implications of this for the proposed TFTA. Results show that member states have revealed comparative advantage in similar products and these products present opportunities for joint-production among member states as well as sectors for product development once the proposed TFTA is in place. Revealed Trade Barrier Indexes were used to gain insights into the extent of ease of market access into each regional bloc’s market. Results from the indexes indicate whether major products imported from each other receive possibly discriminatory or preferential treatment. The results indicate that the majority of the top 5 imports sourced from each region receive preferential treatment. This indicates that there is ease of market access for the top 5 imports sourced from each other and this could promote increased intra-regional trade among member states in these product categories because tariff and non-tariff barriers to trade will be progressively eliminated once the TFTA is in place.
- Full Text:
- Date Issued: 2020
The exploration of ARF1 screening assays to determine the drug status of ARF1 in cancer and malaria
- Authors: Ntlantsana, Apelele
- Date: 2020
- Subjects: ADP ribosylation , Golgi apparatus , Guanosine triphosphatase , G proteins , Malariotherapy , Malaria -- Research , Cancer -- Chemotherapy , Malaria -- Chemotherpay
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167232 , vital:41458
- Description: ARF GTPases are key regulators of the secretory and endocytic pathways. ARF1 is involved in the secretory pathway. ARF1 has been implicated in the endoplasmic reticulum to Golgi transport, function of the Golgi apparatus and transport from the trans-Golgi network to endosomes. ARFs cycle between active GTP-bound and inactive GDP-bound conformations. GDP/GTP cycling is regulated by large families of guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs). ARF GEFs facilitate the activation of ARFs by mediating the exchange of GDP for GTP, while ARF GAPs terminate ARF function by stimulating the hydrolysis of the terminal phosphate group of GTP. Based on existing evidence gained from gene manipulation and cell biological investigations, ARF1 has been shown to be fundamentally important for cancer cell proliferation and metastasis and may be a promising target for the development of anti-cancer drugs. Additionally, the conservation of ARFs in eukaryotic organisms leads to an interesting question of whether a single drug target can be used to target multiple diseases. In this case, can a human cancer drug employed for cancer therapy be used in anti-malarial drug therapies? To confirm the drug target status of ARFs using chemical validation experiments, novel inhibitory compounds are needed. This requires the development of complex in vitro protein- protein interaction assays that can be used to screen chemical libraries for ARF GTPase inhibitors. In this study, we developed a fluorescence resonance energy transfer (FRET) assay and a novel in vitro colorimetric plate-based assay to detect the activation status of truncated human and Plasmodium falciparum ARF1. In the case of the FRET assay, active (GTP-bound) and inactive (GDP-bound) ARF1 could be distinguished with Z-factor values >0.5, suggesting that further development of the assay format to identify GEF and GAP inhibitors may be feasible. In the case of the colorimetric assay, robust signals could be detected and the assay was useful for detecting the activation status of ARF1. However, although the activation of ARF1 by the Sec7 domains of the BIG1 and ARNO was detectable, signals were not robust enough to employ in screening campaigns.
- Full Text:
- Date Issued: 2020
- Authors: Ntlantsana, Apelele
- Date: 2020
- Subjects: ADP ribosylation , Golgi apparatus , Guanosine triphosphatase , G proteins , Malariotherapy , Malaria -- Research , Cancer -- Chemotherapy , Malaria -- Chemotherpay
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167232 , vital:41458
- Description: ARF GTPases are key regulators of the secretory and endocytic pathways. ARF1 is involved in the secretory pathway. ARF1 has been implicated in the endoplasmic reticulum to Golgi transport, function of the Golgi apparatus and transport from the trans-Golgi network to endosomes. ARFs cycle between active GTP-bound and inactive GDP-bound conformations. GDP/GTP cycling is regulated by large families of guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs). ARF GEFs facilitate the activation of ARFs by mediating the exchange of GDP for GTP, while ARF GAPs terminate ARF function by stimulating the hydrolysis of the terminal phosphate group of GTP. Based on existing evidence gained from gene manipulation and cell biological investigations, ARF1 has been shown to be fundamentally important for cancer cell proliferation and metastasis and may be a promising target for the development of anti-cancer drugs. Additionally, the conservation of ARFs in eukaryotic organisms leads to an interesting question of whether a single drug target can be used to target multiple diseases. In this case, can a human cancer drug employed for cancer therapy be used in anti-malarial drug therapies? To confirm the drug target status of ARFs using chemical validation experiments, novel inhibitory compounds are needed. This requires the development of complex in vitro protein- protein interaction assays that can be used to screen chemical libraries for ARF GTPase inhibitors. In this study, we developed a fluorescence resonance energy transfer (FRET) assay and a novel in vitro colorimetric plate-based assay to detect the activation status of truncated human and Plasmodium falciparum ARF1. In the case of the FRET assay, active (GTP-bound) and inactive (GDP-bound) ARF1 could be distinguished with Z-factor values >0.5, suggesting that further development of the assay format to identify GEF and GAP inhibitors may be feasible. In the case of the colorimetric assay, robust signals could be detected and the assay was useful for detecting the activation status of ARF1. However, although the activation of ARF1 by the Sec7 domains of the BIG1 and ARNO was detectable, signals were not robust enough to employ in screening campaigns.
- Full Text:
- Date Issued: 2020
Understanding the underlying resistance mechanism of Mycobacterium tuberculosis against Rifampicin by analyzing mutant DNA - directed RNA polymerase proteins via bioinformatics approaches
- Authors: Monama, Mokgerwa Zacharia
- Date: 2020
- Subjects: Mycobacterium tuberculosis , Rifampin , Drug resistance , Homology (Biology) , Tuberculosis -- Chemotherapy
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167508 , vital:41487
- Description: Tuberculosis or TB is an airborne disease caused by the non-motile bacilli, Mycobacterium tuberculosis (MTB). There are two main forms of TB, namely, latent TB or LTB, asymptomatic and non-contagious version which according to the World Health Organization (WHO) is estimated to afflict over a third of the world’s population; and active TB or ATB, a symptomatic and contagious version which continues to spread, affecting millions worldwide. With the already high reported prevalence of TB, the emergence of drug-resistant strains has prompted the development of novel approaches to enhance the efficacy of known drugs and a desperate search for novel compounds to combat MTB infections. It was for this very purpose that this study was conducted. A look into the resistance mechanism of Rifampicin (Rifampin or RIF), one of the more potent first-line drugs, might prove beneficial in predicting the consequence of an introduced mutation (which usually occur as single nucleotide polymorphisms or SNPs) and perhaps even overcome it using appropriate therapeutic interventions that improve RIF’s efficacy. To accomplish this task, models of acceptable quality were generated for the WT and clinically relevant, RIF resistance conferring, SNPs occurring at codon positions D516, H526 and S531 (E .coli numbering system) using MODELLER. The models were accordingly ranked using GA341 and z-DOPE score, and subsequently validated with QMEAN, PROCHECK and VERIFY3D. MD simulations spanning 100 ns were run for RIF-bound (complex) and RIF-free (holo) DNA-directed RNA polymerase (DDRP) protein systems for the WT and SNP mutants using GROMACS. The MD frames were analyzed using RMSD, Rg and RMSF. For further analysis, MD-TASK was used to analyze the calculated dynamic residue networks (DRNs) from the generated MD frames, determining both change in average shortest path (ΔL) and betweenness centrality (ΔBC). The RMSD analysis revealed that all of the SNP complex models displayed a level instability higher than that of the WT complex. A majority of the SNP complex models were also observed to have similar compactness to the WT holo when looking at the calculated Rg. The RMSF results also hinted towards possible physiological consequences of the mutations (generally referred to as a fitness cost) highlighted by the increased fluctuations of the zinc-binding domain and the MTB SI α helical coiled coil. For the first time, to the knowledge of the authors, DRN analysis was employed for the DDRP protein for both holo and complex systems, revealing insightful information about the residues that play a key role in the change in distance between residue pairs along with residues that play an essential role in protein communication within the calculated RIN. Overall, the data supported the conclusions drawn by a recent study that only concentrated on RIF-resistance in rpoB models which suggested that the binding pocket for the SNP models may result in the changed coordination of RIF which may be the main contributor to its impaired efficacy.
- Full Text:
- Date Issued: 2020
- Authors: Monama, Mokgerwa Zacharia
- Date: 2020
- Subjects: Mycobacterium tuberculosis , Rifampin , Drug resistance , Homology (Biology) , Tuberculosis -- Chemotherapy
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167508 , vital:41487
- Description: Tuberculosis or TB is an airborne disease caused by the non-motile bacilli, Mycobacterium tuberculosis (MTB). There are two main forms of TB, namely, latent TB or LTB, asymptomatic and non-contagious version which according to the World Health Organization (WHO) is estimated to afflict over a third of the world’s population; and active TB or ATB, a symptomatic and contagious version which continues to spread, affecting millions worldwide. With the already high reported prevalence of TB, the emergence of drug-resistant strains has prompted the development of novel approaches to enhance the efficacy of known drugs and a desperate search for novel compounds to combat MTB infections. It was for this very purpose that this study was conducted. A look into the resistance mechanism of Rifampicin (Rifampin or RIF), one of the more potent first-line drugs, might prove beneficial in predicting the consequence of an introduced mutation (which usually occur as single nucleotide polymorphisms or SNPs) and perhaps even overcome it using appropriate therapeutic interventions that improve RIF’s efficacy. To accomplish this task, models of acceptable quality were generated for the WT and clinically relevant, RIF resistance conferring, SNPs occurring at codon positions D516, H526 and S531 (E .coli numbering system) using MODELLER. The models were accordingly ranked using GA341 and z-DOPE score, and subsequently validated with QMEAN, PROCHECK and VERIFY3D. MD simulations spanning 100 ns were run for RIF-bound (complex) and RIF-free (holo) DNA-directed RNA polymerase (DDRP) protein systems for the WT and SNP mutants using GROMACS. The MD frames were analyzed using RMSD, Rg and RMSF. For further analysis, MD-TASK was used to analyze the calculated dynamic residue networks (DRNs) from the generated MD frames, determining both change in average shortest path (ΔL) and betweenness centrality (ΔBC). The RMSD analysis revealed that all of the SNP complex models displayed a level instability higher than that of the WT complex. A majority of the SNP complex models were also observed to have similar compactness to the WT holo when looking at the calculated Rg. The RMSF results also hinted towards possible physiological consequences of the mutations (generally referred to as a fitness cost) highlighted by the increased fluctuations of the zinc-binding domain and the MTB SI α helical coiled coil. For the first time, to the knowledge of the authors, DRN analysis was employed for the DDRP protein for both holo and complex systems, revealing insightful information about the residues that play a key role in the change in distance between residue pairs along with residues that play an essential role in protein communication within the calculated RIN. Overall, the data supported the conclusions drawn by a recent study that only concentrated on RIF-resistance in rpoB models which suggested that the binding pocket for the SNP models may result in the changed coordination of RIF which may be the main contributor to its impaired efficacy.
- Full Text:
- Date Issued: 2020
Visualising Chinese presence: an analysis of the contemporary arts of Zambia and Zimbabwe
- Authors: Zhang, Lifang
- Date: 2020
- Subjects: Art, Modern -- 21st century , Art, Modern -- 21st century -- Chinese influences , China -- Relations -- Zambia , China -- Relations -- Zimbabwe , Art and society -- Zambia , Social practice (Art) -- Zambia , Art and globalization -- Zambia , Art and society -- Zimbabwe , Social practice (Art) -- Zimbabwe , Art and globalization -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/146618 , vital:38542
- Description: With the revival and rapid growth of relations between China and African countries in the present century, the “China-Africa relationship” has become a topic of close attention globally and the media and politicians have been dominating the mainstream discourses with dichotomised narratives. China-Africa engagement has also spurred academic research, most of which is oriented toward large-scale economic, political, and strategic concerns. In this context, it is significant to conduct in-depth research exploring specific engagement between Chinese and African people on the ground. Contemporary artists based in Africa have started to represent, through artworks and performances, their experiences and expressions of relations between China and various African countries. However, an examination of twenty-first century connections between Africa and China in relation to the contemporary visual arts is a new area of study and only a limited number of scholarly works exist. To contribute to the research in this area, this thesis explores the ways in which artists engage with specific realities and lived-experiences of Chinese presence through their artistic practices, with a focus on a selection of artists from Zambia and Zimbabwe. Through visual analysis, interviews and field work, this thesis provides a systematic investigation of contemporary arts of Zambia and Zimbabwe in relation to Africa- China encounters, engaging with four aspects: the discursive field, the material presence, individual experiences of encounters, and the broader relational connections within the arts. This thesis argues that, motivated by the histories and realities of African societies, artists from Zambia and Zimbabwe, through their artistic practices, form part of the Africa-China engagement and insert their agencies in the south-south relations between Africans and Chinese. Therefore, this thesis demonstrates the value in approaching the broader discussion on Africa-China engagements from the perspective of contemporary art, arguing that, with the social concerns of the artists and the expressive capacity of creative forms, visual arts are able to embrace diversity, dynamics, complexities and contradictions, and, therefore, can develop the topic beyond the stereotypical narratives about Africa-China relations to a more nuanced understanding of African-Chinese encounters in specific contexts.
- Full Text:
- Date Issued: 2020
- Authors: Zhang, Lifang
- Date: 2020
- Subjects: Art, Modern -- 21st century , Art, Modern -- 21st century -- Chinese influences , China -- Relations -- Zambia , China -- Relations -- Zimbabwe , Art and society -- Zambia , Social practice (Art) -- Zambia , Art and globalization -- Zambia , Art and society -- Zimbabwe , Social practice (Art) -- Zimbabwe , Art and globalization -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/146618 , vital:38542
- Description: With the revival and rapid growth of relations between China and African countries in the present century, the “China-Africa relationship” has become a topic of close attention globally and the media and politicians have been dominating the mainstream discourses with dichotomised narratives. China-Africa engagement has also spurred academic research, most of which is oriented toward large-scale economic, political, and strategic concerns. In this context, it is significant to conduct in-depth research exploring specific engagement between Chinese and African people on the ground. Contemporary artists based in Africa have started to represent, through artworks and performances, their experiences and expressions of relations between China and various African countries. However, an examination of twenty-first century connections between Africa and China in relation to the contemporary visual arts is a new area of study and only a limited number of scholarly works exist. To contribute to the research in this area, this thesis explores the ways in which artists engage with specific realities and lived-experiences of Chinese presence through their artistic practices, with a focus on a selection of artists from Zambia and Zimbabwe. Through visual analysis, interviews and field work, this thesis provides a systematic investigation of contemporary arts of Zambia and Zimbabwe in relation to Africa- China encounters, engaging with four aspects: the discursive field, the material presence, individual experiences of encounters, and the broader relational connections within the arts. This thesis argues that, motivated by the histories and realities of African societies, artists from Zambia and Zimbabwe, through their artistic practices, form part of the Africa-China engagement and insert their agencies in the south-south relations between Africans and Chinese. Therefore, this thesis demonstrates the value in approaching the broader discussion on Africa-China engagements from the perspective of contemporary art, arguing that, with the social concerns of the artists and the expressive capacity of creative forms, visual arts are able to embrace diversity, dynamics, complexities and contradictions, and, therefore, can develop the topic beyond the stereotypical narratives about Africa-China relations to a more nuanced understanding of African-Chinese encounters in specific contexts.
- Full Text:
- Date Issued: 2020
- «
- ‹
- 1
- ›
- »