A transportation management framework for the Polokwane local municipality during Zion Christian Church (ZCC) Easter weekend pilgrimage
- Authors: Mathebula, Andrew Mabila
- Date: 2020
- Subjects: Transportation -- Management , Urban transportation -- Planning Urban transportation -- Management Christian pilgrims and pilgrimages
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/46152 , vital:39509
- Description: The study investigated the impact of the high volume of vehicular traffic on pilgrims and the community during the Zion Christian Church (ZCC) Easter weekend pilgrimage. The researcher adopted an interpretivist research philosophy, and thus attempted to understand policy, planning, and management of the ZCC Easter pilgrimage through meanings that municipal officials assign to them. The study employed the action research approach by collaborating with the Polokwane Local Municipality (PLM) with a view to evolving lasting solutions to traffic congestion during the Easter weekend. The researchers used the seven-step model proposed by Van Tonder and Dietrichsen (Van Tonder and Dietrichsen, 2008). The justification of the model is that it is aligned with the action research model of Organisational Development (OD). It requires that a diagnosis process should be collaborative and participative towards offering solutions to organisational challenges as opposed to imposing a unilateral theoretical generated solution. This model also fits the ontological stance of the researchers which assumes that reality is co-constructed through engagement with other stakeholders. The researcher conducted semi-structured individual and focus groups discussion (FGD) using openended guides. The data from the informants were collected until a point of saturation. In addition to facilitation FGD discussion, the researcher made his own personal reflection of the participatory action research (PAR). A content analysis method was used to synthesise the qualitative data. The contents were extracted from transcribed interviews. The researcher carefully reviewed the notes several times and coded the notes independently. After that, the researcher coded the codes with each other for any potential contradiction. These codes were converted into themes and sub-themes. The qualitative content analysis process, led by the researcher, was both inductive and deductive. Prior to the inductive process, the researcher listened carefully to the audio recordings transcriptions to get a general understanding of participants’ experiences. The findings indicate that the South African transportation planning approach is ossified and divorced from reality. There is a lacuna to address peak traffic challenges during the Easter weekend and the festive season. It is notable that the government-led seasonal road safety campaigns such as ‘Arrive Alive’ are curiously inadequate to address peak traffic and road accidents challenges in South Africa during the ZCC Easter pilgrimage. The transportation management framework for the PLM as well as a peak traffic standard were developed as part of the study recommendations. These recommendations augur a shift to transport planning in South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Mathebula, Andrew Mabila
- Date: 2020
- Subjects: Transportation -- Management , Urban transportation -- Planning Urban transportation -- Management Christian pilgrims and pilgrimages
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/46152 , vital:39509
- Description: The study investigated the impact of the high volume of vehicular traffic on pilgrims and the community during the Zion Christian Church (ZCC) Easter weekend pilgrimage. The researcher adopted an interpretivist research philosophy, and thus attempted to understand policy, planning, and management of the ZCC Easter pilgrimage through meanings that municipal officials assign to them. The study employed the action research approach by collaborating with the Polokwane Local Municipality (PLM) with a view to evolving lasting solutions to traffic congestion during the Easter weekend. The researchers used the seven-step model proposed by Van Tonder and Dietrichsen (Van Tonder and Dietrichsen, 2008). The justification of the model is that it is aligned with the action research model of Organisational Development (OD). It requires that a diagnosis process should be collaborative and participative towards offering solutions to organisational challenges as opposed to imposing a unilateral theoretical generated solution. This model also fits the ontological stance of the researchers which assumes that reality is co-constructed through engagement with other stakeholders. The researcher conducted semi-structured individual and focus groups discussion (FGD) using openended guides. The data from the informants were collected until a point of saturation. In addition to facilitation FGD discussion, the researcher made his own personal reflection of the participatory action research (PAR). A content analysis method was used to synthesise the qualitative data. The contents were extracted from transcribed interviews. The researcher carefully reviewed the notes several times and coded the notes independently. After that, the researcher coded the codes with each other for any potential contradiction. These codes were converted into themes and sub-themes. The qualitative content analysis process, led by the researcher, was both inductive and deductive. Prior to the inductive process, the researcher listened carefully to the audio recordings transcriptions to get a general understanding of participants’ experiences. The findings indicate that the South African transportation planning approach is ossified and divorced from reality. There is a lacuna to address peak traffic challenges during the Easter weekend and the festive season. It is notable that the government-led seasonal road safety campaigns such as ‘Arrive Alive’ are curiously inadequate to address peak traffic and road accidents challenges in South Africa during the ZCC Easter pilgrimage. The transportation management framework for the PLM as well as a peak traffic standard were developed as part of the study recommendations. These recommendations augur a shift to transport planning in South Africa.
- Full Text:
- Date Issued: 2020
Activity of diverse chalcones against several targets: statistical analysis of a high-throughput virtual screen of a custom chalcone library
- Authors: Sarron, Arthur F D
- Date: 2020
- Subjects: Acetophenone , Benzaldehyde , Ketones , Pyruvate kinase , Drug development , Aromatic compounds , Heat shock proteins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/116028 , vital:34291
- Description: Chalcone family molecules are well known to have therapeutic proprieties (anti-inflammatory, anti-microbial or anti-cancer, etc). However the mechanism of action in some cases is not well known. A virtual library of this family of compounds was constructed using custom scripts, based on the aldol condensation, and this library was modified further to analogues by expansion of the α,β-unsaturated ketone linker. Acetophenone and benzaldehyde derivatives which are available and purchasable were used as a base to design the chalcone virtual library. 8063 chalcones were constructed and geometrically optimized with Gaussian 09. Their physicochemical characteristics linked to the Lipinski rules were analyzed with Knime and CDK. The entire library was after docked against several targets including HIV-1 integrase, MRSA pyruvate kinase, HSP90, COX-1, COX-2, ALR2, MAOA, MAOB, acetylcholinesterase, butyrylcholinesterase and PLA2. With the exception of MAOA, which does not have a crystal structure ligand, all dockings were validated by redocking the original ligand provided by the literature. These targets are known in the literature to be inhibited by chalcone-derivatives. However, specificity of the particular known chalcone inhibitors to the particular targets is not known. To this end the performance of the generated chalcone library against the list of targets was of interest. The binding energy of ligand-protein complexes was generally good across the library. Statistical analysis including principal component analysis and hierarchical clustering analysis were made in order to investigate for any physical/chemical characteristics which might explain what chalcone features affect the binding energy of the ligand-protein complexes. The spherical polar coordinates defining the orientation of the binding poses were also calculated and used in the statistical analysis. The statistical analysis has allowed us to hypothesize the importance of these radial distances and the polar angles of key atoms in the chalcones in binding to the pyruvate kinase crystal structure. This was validated by the docking of another small library of compound models in which the α,β-unsaturated ketone chain of the chalcone was replaced by incrementally longer conjugated chains. Further studies on the chalcones themselves reveal rotameric systems in both cis and trans-configurations (which may impact binding), and also studied was the effect of Topliss-based modification and its impact of binding to HSP90. Molecular dynamics confirmed good binding of identified chalcone hits.
- Full Text:
- Date Issued: 2020
- Authors: Sarron, Arthur F D
- Date: 2020
- Subjects: Acetophenone , Benzaldehyde , Ketones , Pyruvate kinase , Drug development , Aromatic compounds , Heat shock proteins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/116028 , vital:34291
- Description: Chalcone family molecules are well known to have therapeutic proprieties (anti-inflammatory, anti-microbial or anti-cancer, etc). However the mechanism of action in some cases is not well known. A virtual library of this family of compounds was constructed using custom scripts, based on the aldol condensation, and this library was modified further to analogues by expansion of the α,β-unsaturated ketone linker. Acetophenone and benzaldehyde derivatives which are available and purchasable were used as a base to design the chalcone virtual library. 8063 chalcones were constructed and geometrically optimized with Gaussian 09. Their physicochemical characteristics linked to the Lipinski rules were analyzed with Knime and CDK. The entire library was after docked against several targets including HIV-1 integrase, MRSA pyruvate kinase, HSP90, COX-1, COX-2, ALR2, MAOA, MAOB, acetylcholinesterase, butyrylcholinesterase and PLA2. With the exception of MAOA, which does not have a crystal structure ligand, all dockings were validated by redocking the original ligand provided by the literature. These targets are known in the literature to be inhibited by chalcone-derivatives. However, specificity of the particular known chalcone inhibitors to the particular targets is not known. To this end the performance of the generated chalcone library against the list of targets was of interest. The binding energy of ligand-protein complexes was generally good across the library. Statistical analysis including principal component analysis and hierarchical clustering analysis were made in order to investigate for any physical/chemical characteristics which might explain what chalcone features affect the binding energy of the ligand-protein complexes. The spherical polar coordinates defining the orientation of the binding poses were also calculated and used in the statistical analysis. The statistical analysis has allowed us to hypothesize the importance of these radial distances and the polar angles of key atoms in the chalcones in binding to the pyruvate kinase crystal structure. This was validated by the docking of another small library of compound models in which the α,β-unsaturated ketone chain of the chalcone was replaced by incrementally longer conjugated chains. Further studies on the chalcones themselves reveal rotameric systems in both cis and trans-configurations (which may impact binding), and also studied was the effect of Topliss-based modification and its impact of binding to HSP90. Molecular dynamics confirmed good binding of identified chalcone hits.
- Full Text:
- Date Issued: 2020
Addressing flux suppression, radio frequency interference, and selection of optimal solution intervals during radio interferometric calibration
- Authors: Sob, Ulrich Armel Mbou
- Date: 2020
- Subjects: CubiCal (Software) , Radio -- Interference , Imaging systems in astronomy , Algorithms , Astronomical instruments -- Calibration , Astronomy -- Data processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/147714 , vital:38663
- Description: The forthcoming Square Kilometre Array is expected to provide answers to some of the most intriguing questions about our Universe. However, as it is already noticeable from MeerKAT and other precursors, the amounts of data produced by these new instruments are significantly challenging to calibrate and image. Calibration of radio interferometric data is usually biased by incomplete sky models and radio frequency interference (RFI) resulting in calibration artefacts that limit the dynamic range and image fidelity of the resulting images. One of the most noticeable of these artefacts is the formation of spurious sources which causes suppression of real emissions. Fortunately, it has been shown that calibration algorithms employing heavy-tailed likelihood functions are less susceptible to this due to their robustness against outliers. Leveraging on recent developments in the field of complex optimisation, we implement a robust calibration algorithm using a Student’s t likelihood function and Wirtinger derivatives. The new algorithm, dubbed the robust solver, is incorporated as a subroutine into the newly released calibration software package CubiCal. We perform statistical analysis on the distribution of visibilities and provide an insight into the functioning of the robust solver and describe different scenarios where it will improve calibration. We use simulations to show that the robust solver effectively reduces the amount of flux suppressed from unmodelled sources both in direction independent and direction dependent calibration. Furthermore, the robust solver is shown to successfully mitigate the effects of low-level RFI when applied to a simulated and a real VLA dataset. Finally, we demonstrate that there are close links between the amount of flux suppressed from sources, the effects of the RFI and the employed solution interval during radio interferometric calibration. Hence, we investigate the effects of solution intervals and the different factors to consider in order to select adequate solution intervals. Furthermore, we propose a practical brute force method for selecting optimal solution intervals. The proposed method is successfully applied to a VLA dataset.
- Full Text:
- Date Issued: 2020
- Authors: Sob, Ulrich Armel Mbou
- Date: 2020
- Subjects: CubiCal (Software) , Radio -- Interference , Imaging systems in astronomy , Algorithms , Astronomical instruments -- Calibration , Astronomy -- Data processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/147714 , vital:38663
- Description: The forthcoming Square Kilometre Array is expected to provide answers to some of the most intriguing questions about our Universe. However, as it is already noticeable from MeerKAT and other precursors, the amounts of data produced by these new instruments are significantly challenging to calibrate and image. Calibration of radio interferometric data is usually biased by incomplete sky models and radio frequency interference (RFI) resulting in calibration artefacts that limit the dynamic range and image fidelity of the resulting images. One of the most noticeable of these artefacts is the formation of spurious sources which causes suppression of real emissions. Fortunately, it has been shown that calibration algorithms employing heavy-tailed likelihood functions are less susceptible to this due to their robustness against outliers. Leveraging on recent developments in the field of complex optimisation, we implement a robust calibration algorithm using a Student’s t likelihood function and Wirtinger derivatives. The new algorithm, dubbed the robust solver, is incorporated as a subroutine into the newly released calibration software package CubiCal. We perform statistical analysis on the distribution of visibilities and provide an insight into the functioning of the robust solver and describe different scenarios where it will improve calibration. We use simulations to show that the robust solver effectively reduces the amount of flux suppressed from unmodelled sources both in direction independent and direction dependent calibration. Furthermore, the robust solver is shown to successfully mitigate the effects of low-level RFI when applied to a simulated and a real VLA dataset. Finally, we demonstrate that there are close links between the amount of flux suppressed from sources, the effects of the RFI and the employed solution interval during radio interferometric calibration. Hence, we investigate the effects of solution intervals and the different factors to consider in order to select adequate solution intervals. Furthermore, we propose a practical brute force method for selecting optimal solution intervals. The proposed method is successfully applied to a VLA dataset.
- Full Text:
- Date Issued: 2020
An analysis of how visualisation capabilities in dynamic geometric software develop meaning-making of mathematical concepts in selected Grade 11 learners
- Authors: Mavani, Deepack Pravin
- Date: 2020
- Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa , Mathematics -- Computer programs , Mathematics -- Study and teaching (Secondary) -- South Africa -- Case studies , Mathematics -- Study and teaching -- Activity programs , Educational technology , Visualization
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/143213 , vital:38211
- Description: Visualisation plays a central role in developing mathematical ideas because it can be used to make these ideas explicit and visible, and thus has the potential to advance understanding. This study centred around the GeoGebra Literacy Initiative Project (GLIP), a teacher development initiative in Mthatha that aimed to grow and develop appropriate Information and Communication Technology (ICT) skills in teachers, to harness the teaching and learning potential of GeoGebra. GeoGebra is a dynamic geometric software package that is very interactive and makes use of powerful features to create images which can be moved around the computer screen for mathematical exploration. This research project was located within GLIP and analysed how GeoGebra applets develop conceptual and procedural understanding in selected Grade 11 learners. One aspect of GLIP was for teachers to use GeoGebra applets that they had developed themselves and implemented in their classrooms in pre-determined cycles that were aligned to the curriculum. My study specifically focused on how the selected learners made use of these applets and explored how learning had taken place in terms of developing mathematical meaning-making. This interpretive research study was designed as a case study. The case was a cohort of selected Grade 11 learners who had been taught by GLIP teachers, and my unit of analysis was the learners’ interaction with the applets. A screen capturing software package was used to capture learners’ interactions with the GeoGebra. My data consisted mainly of recorded observations and interviews. An analytical framework derived from the works of Kilpatrick, Swafford, and Findell (2001) and Carter et al. (2009) guided and informed the data analysis of the learners’ activities with the GeoGebra. The theoretical orientation of this study was constructivist learning. An in-depth analysis and detailed descriptions of the participants’ interactions enabled me to gain a comprehensive understanding of their meaning-making processes in a technological classroom context. An analysis across the participants identified distinguishable patterns or differences in the development of the learners’ mathematical proficiency and making sense of mathematical ideas. The research argued that technology enabled visualisation was a powerful tool to not only enrich mathematically activities, but to also enrich conceptual and procedural understanding. The findings recognised that exploration of, or manipulation on mathematical objects in GeoGebra was a key activity in the participants’ meaning-making process. It also enabled learners to offer self-proclaimed theories
- Full Text:
- Date Issued: 2020
- Authors: Mavani, Deepack Pravin
- Date: 2020
- Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa , Mathematics -- Computer programs , Mathematics -- Study and teaching (Secondary) -- South Africa -- Case studies , Mathematics -- Study and teaching -- Activity programs , Educational technology , Visualization
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/143213 , vital:38211
- Description: Visualisation plays a central role in developing mathematical ideas because it can be used to make these ideas explicit and visible, and thus has the potential to advance understanding. This study centred around the GeoGebra Literacy Initiative Project (GLIP), a teacher development initiative in Mthatha that aimed to grow and develop appropriate Information and Communication Technology (ICT) skills in teachers, to harness the teaching and learning potential of GeoGebra. GeoGebra is a dynamic geometric software package that is very interactive and makes use of powerful features to create images which can be moved around the computer screen for mathematical exploration. This research project was located within GLIP and analysed how GeoGebra applets develop conceptual and procedural understanding in selected Grade 11 learners. One aspect of GLIP was for teachers to use GeoGebra applets that they had developed themselves and implemented in their classrooms in pre-determined cycles that were aligned to the curriculum. My study specifically focused on how the selected learners made use of these applets and explored how learning had taken place in terms of developing mathematical meaning-making. This interpretive research study was designed as a case study. The case was a cohort of selected Grade 11 learners who had been taught by GLIP teachers, and my unit of analysis was the learners’ interaction with the applets. A screen capturing software package was used to capture learners’ interactions with the GeoGebra. My data consisted mainly of recorded observations and interviews. An analytical framework derived from the works of Kilpatrick, Swafford, and Findell (2001) and Carter et al. (2009) guided and informed the data analysis of the learners’ activities with the GeoGebra. The theoretical orientation of this study was constructivist learning. An in-depth analysis and detailed descriptions of the participants’ interactions enabled me to gain a comprehensive understanding of their meaning-making processes in a technological classroom context. An analysis across the participants identified distinguishable patterns or differences in the development of the learners’ mathematical proficiency and making sense of mathematical ideas. The research argued that technology enabled visualisation was a powerful tool to not only enrich mathematically activities, but to also enrich conceptual and procedural understanding. The findings recognised that exploration of, or manipulation on mathematical objects in GeoGebra was a key activity in the participants’ meaning-making process. It also enabled learners to offer self-proclaimed theories
- Full Text:
- Date Issued: 2020
An audience perception of pentecostal churches’ television programmes on star times and dstv in lagos, Nigeria
- Authors: Olaoye, Adewale Titus
- Date: 2020
- Subjects: Religious broadcasting -- Christianity Television in religion Mass media in religion
- Language: English
- Type: Thesis , Doctoral , PhD (Communication)
- Identifier: http://hdl.handle.net/10353/11418 , vital:39070
- Description: Pentecostal churches in Nigeria are leveraging traditional and new media technologies such as cable or digital satellite television, to broadcast services and programmes to their regular and a growing community of virtual worshippers. Critics of this type of religious outreach now known as televangelism have challenged its predominant, if not exclusive focus on miracle and prosperity message. Using the mixed-method research design involving focus group discussions, key informant interviews and a survey of 255 respondents, this study sought to ascertain Lagos audiences‘ perceptions of Pentecostal Television programmes on two satellite stations, Start Times and DSTV. The findings revealed that audience members perceive Pentecostal churches programme as primarily focused on converting the audience members to the Christian faith. The result revealed that miracle sessions are a common feature of televangelism. Respondents see the miracles as manipulations largely intended to woo and often, hoodwink audience members. The findings revealed that although some of the Pentecostal churches‘ programmes dwell more on the word of God compared to the mainline churches, the programmes and teachings, however, often tended to promote the leadership of the church and not the gospel of Christ. Generally, the study indicates the majority of the audience members are aware of and identify with the atrocities the Pentecostal Churches are accused of perpetrating through their TV programmes. The findings revealed poor awareness and knowledge about the role of the Nigeria Broadcasting Corporation (NBC). The results suggest participants do not believe the NBC is living up to its responsibilities. The findings of this study highlight the need for the NBC, the Christian Association of Nigeria (CAN) and Pentecostal Fellowship of Nigeria (PFN) to work together in formulating new regulations for controlling religious broadcast on television, Pentecostal TV broadcasts, in particular. This is the only way to safeguard vulnerable members of the audience from being manipulated and brainwashed.
- Full Text:
- Date Issued: 2020
- Authors: Olaoye, Adewale Titus
- Date: 2020
- Subjects: Religious broadcasting -- Christianity Television in religion Mass media in religion
- Language: English
- Type: Thesis , Doctoral , PhD (Communication)
- Identifier: http://hdl.handle.net/10353/11418 , vital:39070
- Description: Pentecostal churches in Nigeria are leveraging traditional and new media technologies such as cable or digital satellite television, to broadcast services and programmes to their regular and a growing community of virtual worshippers. Critics of this type of religious outreach now known as televangelism have challenged its predominant, if not exclusive focus on miracle and prosperity message. Using the mixed-method research design involving focus group discussions, key informant interviews and a survey of 255 respondents, this study sought to ascertain Lagos audiences‘ perceptions of Pentecostal Television programmes on two satellite stations, Start Times and DSTV. The findings revealed that audience members perceive Pentecostal churches programme as primarily focused on converting the audience members to the Christian faith. The result revealed that miracle sessions are a common feature of televangelism. Respondents see the miracles as manipulations largely intended to woo and often, hoodwink audience members. The findings revealed that although some of the Pentecostal churches‘ programmes dwell more on the word of God compared to the mainline churches, the programmes and teachings, however, often tended to promote the leadership of the church and not the gospel of Christ. Generally, the study indicates the majority of the audience members are aware of and identify with the atrocities the Pentecostal Churches are accused of perpetrating through their TV programmes. The findings revealed poor awareness and knowledge about the role of the Nigeria Broadcasting Corporation (NBC). The results suggest participants do not believe the NBC is living up to its responsibilities. The findings of this study highlight the need for the NBC, the Christian Association of Nigeria (CAN) and Pentecostal Fellowship of Nigeria (PFN) to work together in formulating new regulations for controlling religious broadcast on television, Pentecostal TV broadcasts, in particular. This is the only way to safeguard vulnerable members of the audience from being manipulated and brainwashed.
- Full Text:
- Date Issued: 2020
An evaluation of programme management with reference to inner -city problem buildings: The case of Nelson Mandela Bay Metropolitan Municipality ,South Africa
- Conradie, Hendrik Francois, Shaidi,Walter
- Authors: Conradie, Hendrik Francois , Shaidi,Walter
- Date: 2020
- Subjects: Municipal government -- South Africa -- Port Elizabeth , Finance,Public --South Africa --Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46670 , vital:39607
- Description: This research study is qualitative and cross-sectional in nature. Programme management by South African city governments is investigated and evaluated, as related to inner-city decay and problem (derelict; hijacked; dilapidated; overcrowded) buildings. A case study approach, focusing on the Nelson Mandela Bay Municipality in Port Elizabeth, South Africa, is utilised to understand the phenomenon, and to answer the research question. The significant challenge of inner-city and central business district problem buildings in major South African cities has prompted the study; no scientific research has previously been conducted or published on this topic The study started out with this research question, asked in a case study context: to what extent are programmes dealing with inner-city problem buildings and decay managed effectively by city government in South Africa? In the literature review the researcher focused on programme management theory, emphasising the usefulness of project management principles and practice in public sector programme management contexts. In a subsequent chapter the applicable constitutional and legislative frameworks were presented. The researcher developed, as outcome, strategic remedial legal options available to city governments when dealing with transgressing owners of problematic buildings. Problem building by-laws were dealt with in detail. A qualitative research approach, including semi-structured in-depth interviews with political and managerial leaders at the case study city government, assisted the researcher in effective data generation. Data analysis was performed with vigour, based on thematic content analysis.relevant coding practices were utilised in analysis and interpretation of data.
- Full Text:
- Date Issued: 2020
- Authors: Conradie, Hendrik Francois , Shaidi,Walter
- Date: 2020
- Subjects: Municipal government -- South Africa -- Port Elizabeth , Finance,Public --South Africa --Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46670 , vital:39607
- Description: This research study is qualitative and cross-sectional in nature. Programme management by South African city governments is investigated and evaluated, as related to inner-city decay and problem (derelict; hijacked; dilapidated; overcrowded) buildings. A case study approach, focusing on the Nelson Mandela Bay Municipality in Port Elizabeth, South Africa, is utilised to understand the phenomenon, and to answer the research question. The significant challenge of inner-city and central business district problem buildings in major South African cities has prompted the study; no scientific research has previously been conducted or published on this topic The study started out with this research question, asked in a case study context: to what extent are programmes dealing with inner-city problem buildings and decay managed effectively by city government in South Africa? In the literature review the researcher focused on programme management theory, emphasising the usefulness of project management principles and practice in public sector programme management contexts. In a subsequent chapter the applicable constitutional and legislative frameworks were presented. The researcher developed, as outcome, strategic remedial legal options available to city governments when dealing with transgressing owners of problematic buildings. Problem building by-laws were dealt with in detail. A qualitative research approach, including semi-structured in-depth interviews with political and managerial leaders at the case study city government, assisted the researcher in effective data generation. Data analysis was performed with vigour, based on thematic content analysis.relevant coding practices were utilised in analysis and interpretation of data.
- Full Text:
- Date Issued: 2020
An evaluation of the cytotoxic activities of novel artemisinin derivatives: towards targeted therapies for triple-negative breast cancers (TNBC)
- Authors: Kajewole, Deborah Ifeoluwa
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/163329 , vital:41029 , doi:10.21504/10962/163329
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020.
- Full Text:
- Date Issued: 2020
- Authors: Kajewole, Deborah Ifeoluwa
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/163329 , vital:41029 , doi:10.21504/10962/163329
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020.
- Full Text:
- Date Issued: 2020
An examination of practices and experiences of teacher educators in the supervision of a national early childhood home based programme
- Authors: Annatolia, Misi
- Date: 2020
- Subjects: Early childhood education -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49362 , vital:41695
- Description: Zimbabwean teacher educators are, by the nature of their job description, required to supervise student teachers doing teaching practicum for the 0-3 home based programme. However, analysis of supervision reports of the home based programme indicates some inconsistencies in comments made by different supervisors, whereby the descriptors and supervision overall scores do not tally. It seems the supervision of the home based teacher education programme is not being implemented as expected. Hence, the purpose of this qualitative case study was to examine practices and experiences of teacher educators in the supervision of a National Early Childhood Development Home Based Teacher Education Programme (NECDHBTEP). The objective of the study was to address the key question: ‘What are the practices and experiences of teacher educators in the supervision of a NECDHBTEP. In addressing the question, the researcher used supervision as a conceptual framework. The theoretical framework which informed the study was Contextual Supervision (CS) which has its philosophical foundations in constructivism, beneficence and justice. Purposive sampling was employed in the study where two primary teachers’ colleges were selected. From each college, ten teacher educators were selected for semi-structured interviews, two focus group discussions and document analysis on teacher educators’ supervision reports. Triangulation of the data was done so as to enhance its trustworthiness. Three major themes emerged from the study, namely, the influence of home context, experience of supervisors on NECDHBTEP and supervision approaches. The study discovered that the home context, to some extent, influences supervision of the NECDHBTEP. The study also established that teacher educators face multiple challenges when supervising student teachers on the ECD home based programme. The researcher made some recommendations from the findings. One of the recommendations was for colleges to develop a specific supervision instrument for the home based ECD supervision (0-3 years category). Furthermore, there is need for Zimbabwean primary teachers’ colleges to engage in rigorous in-service training for lecturers who are not knowledgeable about the NECDHBTEP.
- Full Text:
- Date Issued: 2020
- Authors: Annatolia, Misi
- Date: 2020
- Subjects: Early childhood education -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49362 , vital:41695
- Description: Zimbabwean teacher educators are, by the nature of their job description, required to supervise student teachers doing teaching practicum for the 0-3 home based programme. However, analysis of supervision reports of the home based programme indicates some inconsistencies in comments made by different supervisors, whereby the descriptors and supervision overall scores do not tally. It seems the supervision of the home based teacher education programme is not being implemented as expected. Hence, the purpose of this qualitative case study was to examine practices and experiences of teacher educators in the supervision of a National Early Childhood Development Home Based Teacher Education Programme (NECDHBTEP). The objective of the study was to address the key question: ‘What are the practices and experiences of teacher educators in the supervision of a NECDHBTEP. In addressing the question, the researcher used supervision as a conceptual framework. The theoretical framework which informed the study was Contextual Supervision (CS) which has its philosophical foundations in constructivism, beneficence and justice. Purposive sampling was employed in the study where two primary teachers’ colleges were selected. From each college, ten teacher educators were selected for semi-structured interviews, two focus group discussions and document analysis on teacher educators’ supervision reports. Triangulation of the data was done so as to enhance its trustworthiness. Three major themes emerged from the study, namely, the influence of home context, experience of supervisors on NECDHBTEP and supervision approaches. The study discovered that the home context, to some extent, influences supervision of the NECDHBTEP. The study also established that teacher educators face multiple challenges when supervising student teachers on the ECD home based programme. The researcher made some recommendations from the findings. One of the recommendations was for colleges to develop a specific supervision instrument for the home based ECD supervision (0-3 years category). Furthermore, there is need for Zimbabwean primary teachers’ colleges to engage in rigorous in-service training for lecturers who are not knowledgeable about the NECDHBTEP.
- Full Text:
- Date Issued: 2020
An exploration of how Grade 3 Foundation Phase teachers develop basic scientific process skills using an inquiry-based approach in their classrooms
- Authors: Nhase, Zukiswa
- Date: 2020
- Subjects: Elementary school teaching-- South Africa , Elementary school teachers -- South Africa , Elementary school teachers -- In-service training -- South Africa , Science -- Study and teaching (Elementary) -- South Africa , Learning, Psychology of , Cognition in children , Inquiry-based learning -- South Africa , Active learning -- South Africa , Pedagogical content knowledge -- South Africa , Educational change -- South Africa , Socio-cultural theory
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145181 , vital:38416
- Description: Some studies have looked at Foundation Phase teachers’ perspectives on the teaching of science in this phase. Such studies have highlighted various challenges on the teaching of science in the Foundation Phase. They pointed out issues such as large class numbers, lack of resources and lack of science knowledge from Foundation Phase teachers. However, none of these studies have looked at how Foundation Phase teachers are using an Inquiry-Based Approach in their classrooms instead few studies have looked at the Foundation Phase teachers’ perspectives about scientific inquiry in this phase. Even though many scholars have presented several challenges to the teaching of science both at secondary and primary level, the argument is strongly made that Foundation Phase learners should be exposed to the learning of science. Generally, children at the Foundation Phase level naturally enjoy observing and thinking about nature; exposing learners to science develops positive attitudes towards science; the use of scientifically informed language at an early age influences the eventual development of scientific concepts; children can understand scientific concepts and reason scientifically; and science is an efficient means for developing scientific thinking. It is within these arguments and discussions that this interpretive case study research sought to explore the Pedagogical Content Knowledge of four Foundation Phase teachers in developing the Scientific Process Skills using an Inquiry-Based Approach in their classrooms and subsequently, the significance of this research study. The socio-cultural theory, Topic Specific Pedagogical Content Knowledge, Zaretskii’s six conditions for development during mediation and the principles of an Inquiry-Based Approach were used as analytical lenses in this research. To use an Inquiry-Based Approach, generally teachers have to understand its principles and know how to develop basic Scientific Process Skills while teaching the science content. In the Foundation Phase, the Natural Sciences component or content is embedded in the Beginning Knowledge study area of the Life Skills subject and this can create difficulties for teachers to even recognise the scientific concepts in the Life Skills. The four IsiXhosa female teachers used the home language of learners as the language of instruction to implement an Inquiry-Based Approach in their classrooms. Data were generated in four phases. Phase one was baseline data through document analysis. Three of the phases were directed by the research question asked. Data were generated using questionnaires, interviews (semi-structured and stimulated recall), lesson observations (videotaped) and group reflections and discussions. From the work of Vygotsky, Zaretskii formulated six conditions that can be used to develop learners’ zone of proximal development in learning and these were used as analytical lenses to analyse data to understand how teachers mediated learning and development of Scientific Inquiry in their Grade 3 classrooms. In addition, the principles of an Inquiry-Based Approach were used as analytical lenses as to how teachers implemented the scientific inquiry approach. The categories or components of Topic Specific Pedagogical Content Knowledge were used as analytical lenses as to how these teachers dealt with science concepts or content when using an inquiry-based Approach in their classrooms. Using the home language of learners as an instructional tool, data showed that learners were afforded the opportunity to freely engage in activities and as a result, the context of learning was non-threatening for both teachers and learners. Although learning activities could be improved, teachers created social spaces for learners to take part in learning. In addition, the use of learners’ environments in the observed lessons made it comfortable for learners to act as young scientists. The new knowledge in this research was presented by the use of the adapted analytical tool, which combined diverse components of theory and literature that aligned with each other. The reflection space for the participants did not only afford the participants to discuss about each other’s lessons or experiences in this research, it allowed the participants to engage with the research objectives. The reflection space strengthened the research ethics if this study. Hence, the concept that says, ‘Absenting the absences’. In conclusion, the study thus recommends further professional development spaces that promote community of practice in using an Inquiry-Based Approach in the Foundation Phase.
- Full Text:
- Date Issued: 2020
- Authors: Nhase, Zukiswa
- Date: 2020
- Subjects: Elementary school teaching-- South Africa , Elementary school teachers -- South Africa , Elementary school teachers -- In-service training -- South Africa , Science -- Study and teaching (Elementary) -- South Africa , Learning, Psychology of , Cognition in children , Inquiry-based learning -- South Africa , Active learning -- South Africa , Pedagogical content knowledge -- South Africa , Educational change -- South Africa , Socio-cultural theory
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145181 , vital:38416
- Description: Some studies have looked at Foundation Phase teachers’ perspectives on the teaching of science in this phase. Such studies have highlighted various challenges on the teaching of science in the Foundation Phase. They pointed out issues such as large class numbers, lack of resources and lack of science knowledge from Foundation Phase teachers. However, none of these studies have looked at how Foundation Phase teachers are using an Inquiry-Based Approach in their classrooms instead few studies have looked at the Foundation Phase teachers’ perspectives about scientific inquiry in this phase. Even though many scholars have presented several challenges to the teaching of science both at secondary and primary level, the argument is strongly made that Foundation Phase learners should be exposed to the learning of science. Generally, children at the Foundation Phase level naturally enjoy observing and thinking about nature; exposing learners to science develops positive attitudes towards science; the use of scientifically informed language at an early age influences the eventual development of scientific concepts; children can understand scientific concepts and reason scientifically; and science is an efficient means for developing scientific thinking. It is within these arguments and discussions that this interpretive case study research sought to explore the Pedagogical Content Knowledge of four Foundation Phase teachers in developing the Scientific Process Skills using an Inquiry-Based Approach in their classrooms and subsequently, the significance of this research study. The socio-cultural theory, Topic Specific Pedagogical Content Knowledge, Zaretskii’s six conditions for development during mediation and the principles of an Inquiry-Based Approach were used as analytical lenses in this research. To use an Inquiry-Based Approach, generally teachers have to understand its principles and know how to develop basic Scientific Process Skills while teaching the science content. In the Foundation Phase, the Natural Sciences component or content is embedded in the Beginning Knowledge study area of the Life Skills subject and this can create difficulties for teachers to even recognise the scientific concepts in the Life Skills. The four IsiXhosa female teachers used the home language of learners as the language of instruction to implement an Inquiry-Based Approach in their classrooms. Data were generated in four phases. Phase one was baseline data through document analysis. Three of the phases were directed by the research question asked. Data were generated using questionnaires, interviews (semi-structured and stimulated recall), lesson observations (videotaped) and group reflections and discussions. From the work of Vygotsky, Zaretskii formulated six conditions that can be used to develop learners’ zone of proximal development in learning and these were used as analytical lenses to analyse data to understand how teachers mediated learning and development of Scientific Inquiry in their Grade 3 classrooms. In addition, the principles of an Inquiry-Based Approach were used as analytical lenses as to how teachers implemented the scientific inquiry approach. The categories or components of Topic Specific Pedagogical Content Knowledge were used as analytical lenses as to how these teachers dealt with science concepts or content when using an inquiry-based Approach in their classrooms. Using the home language of learners as an instructional tool, data showed that learners were afforded the opportunity to freely engage in activities and as a result, the context of learning was non-threatening for both teachers and learners. Although learning activities could be improved, teachers created social spaces for learners to take part in learning. In addition, the use of learners’ environments in the observed lessons made it comfortable for learners to act as young scientists. The new knowledge in this research was presented by the use of the adapted analytical tool, which combined diverse components of theory and literature that aligned with each other. The reflection space for the participants did not only afford the participants to discuss about each other’s lessons or experiences in this research, it allowed the participants to engage with the research objectives. The reflection space strengthened the research ethics if this study. Hence, the concept that says, ‘Absenting the absences’. In conclusion, the study thus recommends further professional development spaces that promote community of practice in using an Inquiry-Based Approach in the Foundation Phase.
- Full Text:
- Date Issued: 2020
An integrative approach to understanding vulnerability of an alpine range-restricted bird to climate warming
- Authors: Oswald, Krista Natasha
- Date: 2020
- Subjects: Passeriformes -- South Africa -- Western Cape , Passeriformes -- Physiology -- South Africa -- Western Cape , Passeriformes -- Behavior -- Climatic factors -- South Africa -- Western Cape , Passeriformes -- Reproduction -- Climatic factors -- South Africa -- Western Cape , Passeriformes -- Dispersal -- South Africa -- Western Cape , Passeriformes -- Food -- South Africa -- Western Cape , Passeriformes -- Nests-- South Africa -- Western Cape , Blue Hill Nature Reserve , Cape Rockjumper -- Climatic factors , Chaetops frenatus
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/148517 , vital:38746
- Description: Understanding species' vulnerability to climate change requires an integrative ecological approach involving, at minimum, physiology, behaviour, reproductive success, and limitations on dispersal. In this thesis I determined potential negative effects of increasing temperatures on behaviour, reproduction, and ability to disperse in an alpine-restricted bird, the Cape Rockjumper Chaetops frenatus ("Rockjumper"). Here I provide a comprehensive ecological set of data for understanding the link between Rockjumper population declines and warming habitats. I tested whether Rockjumper microsite-use at high temperatures resulted in decreased time spent on important behaviours, such as foraging. I found Rockjumpers made increased use of rock-shade as air temperature increased and so spent less time panting, but birds in rock-shade foraged less. Birds may be constrained to foraging in sun at high temperatures to sustain energy or water requirements, despite risks of high thermal load, or else face lost foraging opportunities by remaining in rock-shade. I determined if adult nest attendance and causes of nest failure were related to high temperatures. I filmed nests over two breeding seasons to examine temperature-effects on adult time in nests, provisioning rate, and resultant nestling daily mass gain. The only temperature effect I found was decreased percent daily change in body mass for older nestlings at hotter temperatures. I also examined causes of nest failure over three breeding seasons in relation to nest concealment and habitat openness by observing failure/success. Nests in more open territories (i.e. early post-fire habitat) had greater success, and the main cause of predation came from Boomslang Dispholydus typus. Importantly, the probability of Boomslang predation increased significantly at hotter temperatures. These findings show there may be direct negative effects of increasing temperatures on reproductive success and population recruitment, and so hotter temperature during the breeding season may be at least partly responsible for observed population declines. Lastly, I examined genetic structure of populations across mountain ranges separated from one another by lowland habitat unsuitable for Rockjumpers. I predicted I would find little evidence for dispersal between mountain ranges separated by unsuitable lowland habitat, but instead found Rockjumpers show little evidence for inbreeding. I also found evidence for a past bottleneck event or founder effect, and little overall genetic diversity (possibly as their specialized niche exerts selective pressure). Low diversity may limit Rockjumpers' ability to adapt to a changing environment. Adult physiological and behavioural thresholds to increasing temperatures are often used to create predictions of climate change effects. My past physiological research and current behavioural research suggest no particularly strong evidence that temperature-related population declines are driven by poor physiological capacity to tolerate heat or negative behaviour trade-offs. Instead, my current research shows that understanding negative effects of increasing temperatures may require a more in-depth approach involving investigation of fine-scale ecological interactions. No single one of my chapters provides the insight necessary for understanding Rockjumper population declines at warming temperatures. Instead, I show how an integrative approach may be necessary for assessing species' vulnerability to climate change by examining multiple ecological aspects of a single sentinel species, using an alpine species with a narrow thermal range and highly specialized habitat niche.
- Full Text:
- Date Issued: 2020
- Authors: Oswald, Krista Natasha
- Date: 2020
- Subjects: Passeriformes -- South Africa -- Western Cape , Passeriformes -- Physiology -- South Africa -- Western Cape , Passeriformes -- Behavior -- Climatic factors -- South Africa -- Western Cape , Passeriformes -- Reproduction -- Climatic factors -- South Africa -- Western Cape , Passeriformes -- Dispersal -- South Africa -- Western Cape , Passeriformes -- Food -- South Africa -- Western Cape , Passeriformes -- Nests-- South Africa -- Western Cape , Blue Hill Nature Reserve , Cape Rockjumper -- Climatic factors , Chaetops frenatus
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/148517 , vital:38746
- Description: Understanding species' vulnerability to climate change requires an integrative ecological approach involving, at minimum, physiology, behaviour, reproductive success, and limitations on dispersal. In this thesis I determined potential negative effects of increasing temperatures on behaviour, reproduction, and ability to disperse in an alpine-restricted bird, the Cape Rockjumper Chaetops frenatus ("Rockjumper"). Here I provide a comprehensive ecological set of data for understanding the link between Rockjumper population declines and warming habitats. I tested whether Rockjumper microsite-use at high temperatures resulted in decreased time spent on important behaviours, such as foraging. I found Rockjumpers made increased use of rock-shade as air temperature increased and so spent less time panting, but birds in rock-shade foraged less. Birds may be constrained to foraging in sun at high temperatures to sustain energy or water requirements, despite risks of high thermal load, or else face lost foraging opportunities by remaining in rock-shade. I determined if adult nest attendance and causes of nest failure were related to high temperatures. I filmed nests over two breeding seasons to examine temperature-effects on adult time in nests, provisioning rate, and resultant nestling daily mass gain. The only temperature effect I found was decreased percent daily change in body mass for older nestlings at hotter temperatures. I also examined causes of nest failure over three breeding seasons in relation to nest concealment and habitat openness by observing failure/success. Nests in more open territories (i.e. early post-fire habitat) had greater success, and the main cause of predation came from Boomslang Dispholydus typus. Importantly, the probability of Boomslang predation increased significantly at hotter temperatures. These findings show there may be direct negative effects of increasing temperatures on reproductive success and population recruitment, and so hotter temperature during the breeding season may be at least partly responsible for observed population declines. Lastly, I examined genetic structure of populations across mountain ranges separated from one another by lowland habitat unsuitable for Rockjumpers. I predicted I would find little evidence for dispersal between mountain ranges separated by unsuitable lowland habitat, but instead found Rockjumpers show little evidence for inbreeding. I also found evidence for a past bottleneck event or founder effect, and little overall genetic diversity (possibly as their specialized niche exerts selective pressure). Low diversity may limit Rockjumpers' ability to adapt to a changing environment. Adult physiological and behavioural thresholds to increasing temperatures are often used to create predictions of climate change effects. My past physiological research and current behavioural research suggest no particularly strong evidence that temperature-related population declines are driven by poor physiological capacity to tolerate heat or negative behaviour trade-offs. Instead, my current research shows that understanding negative effects of increasing temperatures may require a more in-depth approach involving investigation of fine-scale ecological interactions. No single one of my chapters provides the insight necessary for understanding Rockjumper population declines at warming temperatures. Instead, I show how an integrative approach may be necessary for assessing species' vulnerability to climate change by examining multiple ecological aspects of a single sentinel species, using an alpine species with a narrow thermal range and highly specialized habitat niche.
- Full Text:
- Date Issued: 2020
An intervention on supporting teachers’ understanding of and mediation of learning of stoichiometry in selected schools in the Zambezi Region
- Authors: Denuga, Desalu Dedayo
- Date: 2020
- Subjects: Stoichiometry -- Study and teaching (Secondary) -- Namibia , Chemistry -- Study and teaching (Secondary) -- Namibia , Participant observation -- Namibia , Constructivism (Education) -- Namibia , Pedagogical content knowledge -- Namibia , Continuing education -- Namibia , Teachers -- In-service training -- Namibia
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/103855 , vital:32315
- Description: This study has been triggered by the results on stoichiometry questions in the Directorate of Namibian Examination Assessment’s (DNEA) scripts. As highlighted in the examiners’ reports, stoichiometry is an ongoing annual problem for most students in Namibia. It is against this background that I decided to explore the possibility of an intervention in the form of continuing professional development (CPD) and collaboration workshops to improve the understanding and the mediation of learning of stoichiometry by Physical Science teachers in the Zambezi Region of Namibia. The study was underpinned by an interpretive paradigm and within this paradigm a qualitative case study approach was adopted. Since this study was in a form of an intervention, a participatory action research (PAR) approach was employed within the community of practice (CoP). I used document analysis, workshop discussions, observations and videotaped lessons, interviews (semi-structured and stimulated recall interviews) and reflections to gather data. The study was carried out at three senior secondary schools and six Physical Science teachers were involved. The study drew on the theory of constructivism as a theoretical framework, namely, Piaget’s cognitive constructivism and Vygotsky‘s social constructivism as well as Shulman’s pedagogical content knowledge (PCK). Within PCK, Mavhunga and Rollnick’s Topic Specific Pedagogical Content Knowledge (TSPCK) was used as an analytical lens (Appendix L) in this study. The findings reveal that the use of a diagnostic test on learners made the Physical Science teachers aware of the learners’ challenges and what was difficult for them to understand in stoichiometry. It also helped in their understanding of the use of prior knowledge, one of the tenets of TSPCK, to access what learners knew about stoichiometry. Further findings of the study illuminate that the Physical Science teachers’ subject matter knowledge, pedagogical content knowledge and skills had shifted as a result of their participation in the intervention workshops. The findings of this study indicate that the CoP members acquired the professional transformations which were important breakthroughs in their careers. The study thus recommends that teachers should develop effective teacher professional development activities such as study teams, exemplary lessons, cluster teaching, and peer coaching where teachers are expected to examine their assumptions and practices continuously. The implication of my study is that the developed exemplary lesson during the intervention workshops by CoP members could be useful to other Physical Science teachers in the teaching of stoichiometry in all the schools in the Zambezi Region.
- Full Text:
- Date Issued: 2020
- Authors: Denuga, Desalu Dedayo
- Date: 2020
- Subjects: Stoichiometry -- Study and teaching (Secondary) -- Namibia , Chemistry -- Study and teaching (Secondary) -- Namibia , Participant observation -- Namibia , Constructivism (Education) -- Namibia , Pedagogical content knowledge -- Namibia , Continuing education -- Namibia , Teachers -- In-service training -- Namibia
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/103855 , vital:32315
- Description: This study has been triggered by the results on stoichiometry questions in the Directorate of Namibian Examination Assessment’s (DNEA) scripts. As highlighted in the examiners’ reports, stoichiometry is an ongoing annual problem for most students in Namibia. It is against this background that I decided to explore the possibility of an intervention in the form of continuing professional development (CPD) and collaboration workshops to improve the understanding and the mediation of learning of stoichiometry by Physical Science teachers in the Zambezi Region of Namibia. The study was underpinned by an interpretive paradigm and within this paradigm a qualitative case study approach was adopted. Since this study was in a form of an intervention, a participatory action research (PAR) approach was employed within the community of practice (CoP). I used document analysis, workshop discussions, observations and videotaped lessons, interviews (semi-structured and stimulated recall interviews) and reflections to gather data. The study was carried out at three senior secondary schools and six Physical Science teachers were involved. The study drew on the theory of constructivism as a theoretical framework, namely, Piaget’s cognitive constructivism and Vygotsky‘s social constructivism as well as Shulman’s pedagogical content knowledge (PCK). Within PCK, Mavhunga and Rollnick’s Topic Specific Pedagogical Content Knowledge (TSPCK) was used as an analytical lens (Appendix L) in this study. The findings reveal that the use of a diagnostic test on learners made the Physical Science teachers aware of the learners’ challenges and what was difficult for them to understand in stoichiometry. It also helped in their understanding of the use of prior knowledge, one of the tenets of TSPCK, to access what learners knew about stoichiometry. Further findings of the study illuminate that the Physical Science teachers’ subject matter knowledge, pedagogical content knowledge and skills had shifted as a result of their participation in the intervention workshops. The findings of this study indicate that the CoP members acquired the professional transformations which were important breakthroughs in their careers. The study thus recommends that teachers should develop effective teacher professional development activities such as study teams, exemplary lessons, cluster teaching, and peer coaching where teachers are expected to examine their assumptions and practices continuously. The implication of my study is that the developed exemplary lesson during the intervention workshops by CoP members could be useful to other Physical Science teachers in the teaching of stoichiometry in all the schools in the Zambezi Region.
- Full Text:
- Date Issued: 2020
An investigation into the nature and adequacy of tax compliance tools available to assist small businesses in the state of Oklahoma in the United States of America
- Authors: Cary, Cindi L
- Date: 2020
- Subjects: Tax administration and procedure -- United States , United States. Internal Revenue Service , Small business -- Oklahoma , Small business -- United States , Taxpayer compliance -- Oklahoma , Taxpayer compliance -- United States
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/141015 , vital:37937
- Description: This study identifies and analyses the effectiveness of the tax tools available to the small businesses that make up more than 99 per cent of all businesses in the United States and the state of Oklahoma through an extensive investigation of the small business resources offered by federal and state government agencies, higher education institutions and the professional accounting community. The study uses numerous measurements in order to acquire multiple perspectives and relies on the examination of government websites and documents, interviews, experiments, surveys, and questionnaires to determine the existing small business tax tools and their limitations. The research offers an in-depth analysis of the facts and limitations of the small business services offered by the Internal Revenue Service (IRS). The IRS is determined the largest source of small business tax tools, but limitations plague their effectiveness. Higher education is found guilty of not providing small business education in business or accounting disciplines, leaving college graduates ill-prepared to assist small businesses. Higher education is urged to implement a small business accounting curriculum that couples field experience with classroom lectures and textbooks. This study finds the accounting profession apathetic with regard to informing small businesses of accounting services and presses certified public accountants to be more involved in the education of future small business accountants. The study concludes with recommendations to reduce the small business tax burden by improving the existing small business tax tools.
- Full Text:
- Date Issued: 2020
- Authors: Cary, Cindi L
- Date: 2020
- Subjects: Tax administration and procedure -- United States , United States. Internal Revenue Service , Small business -- Oklahoma , Small business -- United States , Taxpayer compliance -- Oklahoma , Taxpayer compliance -- United States
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/141015 , vital:37937
- Description: This study identifies and analyses the effectiveness of the tax tools available to the small businesses that make up more than 99 per cent of all businesses in the United States and the state of Oklahoma through an extensive investigation of the small business resources offered by federal and state government agencies, higher education institutions and the professional accounting community. The study uses numerous measurements in order to acquire multiple perspectives and relies on the examination of government websites and documents, interviews, experiments, surveys, and questionnaires to determine the existing small business tax tools and their limitations. The research offers an in-depth analysis of the facts and limitations of the small business services offered by the Internal Revenue Service (IRS). The IRS is determined the largest source of small business tax tools, but limitations plague their effectiveness. Higher education is found guilty of not providing small business education in business or accounting disciplines, leaving college graduates ill-prepared to assist small businesses. Higher education is urged to implement a small business accounting curriculum that couples field experience with classroom lectures and textbooks. This study finds the accounting profession apathetic with regard to informing small businesses of accounting services and presses certified public accountants to be more involved in the education of future small business accountants. The study concludes with recommendations to reduce the small business tax burden by improving the existing small business tax tools.
- Full Text:
- Date Issued: 2020
An investigation of the experiences of psychotherapists regarding Ubuntu in their psychotherapy practice: an interpretative phenomenological analysis
- Authors: Qangule, Lumka Sybil
- Date: 2020
- Subjects: Ubuntu (Philosophy) , Psychotherapy -- Cross-cultural studies , Psychoanalysis and culture -- South Africa , Xhosa (African people) -- Psychology , Xhosa (African people) -- Mental health , Black people -- South Africa -- Psychology , Black people -- South Africa -- Mental health , Psychotherapists -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146923 , vital:38577
- Description: Psychotherapy is a Eurocentric concept and practice that has migrated to South Africa with technology, as part of the general transfer of knowledge (Mkhize, 2003). It has embedded Eurocentric principles that sometimes do not easily accommodate working with Africans. It has been practised by psychotherapists of African origin with clients of African origin, but is based upon Eurocentric ideas and guidelines for practice. Many African people consider their core values to be uBuntu, rooted in a principle ‘umntu ngumntu ngabantu’ (translated as ‘a human being is a human being because of other human beings’). Some important features of uBuntu are interdependence, respect, spirituality and the primacy of communality as an approach to life. Some of the ways in which these impact on daily functioning are not foregrounded by adherence to Western principles. The use of only Eurocentric principles when working with clients of African origin may thus not lead to the desired outcomes in psychotherapy. However, these Eurocentric principles are recognised and enforced by the authoritative bodies in the field of psychology, such as the Health Professions Council of South Africa. A distinction will be made between the more inflexible ethical principles of psychology and the ideas of therapy frames. Therapy frames are not seen as being as rigid as ethical codes and they could be augmented, to be appropriate for the context, particularly in the commonly multicultural settings that are found here. Psychotherapists of African origin are torn between abiding by the ethical principles that they have been taught and practising in the way that they, together with their clients, have been socialised. Abiding by the principles as described in the codes is safe because it does not pose any threat of being sanctioned by the regulator of practice, but clients may be let down and there may be limited success with certain clients. This clash of ideas of ways of practice poses dissonance and many dilemmas among psychotherapists of African origin. Due to the nature of this study, Interpretative Phenomenological Analysis (IPA) was adopted as a suitable methodology, where eight practising amaXhosa psychotherapists were interviewed about their experiences of incorporating uBuntu in their psychotherapy practice. The raw data from initial interviews were analysed and the findings concluded that although psychotherapists were trained in Western ways of practice, they included some practices of uBuntu in their practice as well as upholding some Eurocentric principles that seemed to be helpful for their clientele. Subsequently a summary of the findings were discussed with participants in a focus group setting, where participants endorsed and expanded upon their original responses. With the above in mind, a psychotherapy model called uBuntu-Centred Psychotherapy was created, which reflects the principles and therapy frames that have been found to be useful in treating clients of African origin. This modality is more congruent with the worldviews and style of living of many South Africans, in the post-apartheid era. It embraces some Eurocentric principles that are relevant for Africans, while it is embedded in the phenomena and way of life reflected in uBuntu, a predominant mode of functioning for the group that was the focus of this study, the amaXhosa. The study ends by making recommendations for practice, as well as highlighting the need for further and more extensive research to contribute to the project of Africanising psychotherapy.
- Full Text:
- Date Issued: 2020
- Authors: Qangule, Lumka Sybil
- Date: 2020
- Subjects: Ubuntu (Philosophy) , Psychotherapy -- Cross-cultural studies , Psychoanalysis and culture -- South Africa , Xhosa (African people) -- Psychology , Xhosa (African people) -- Mental health , Black people -- South Africa -- Psychology , Black people -- South Africa -- Mental health , Psychotherapists -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146923 , vital:38577
- Description: Psychotherapy is a Eurocentric concept and practice that has migrated to South Africa with technology, as part of the general transfer of knowledge (Mkhize, 2003). It has embedded Eurocentric principles that sometimes do not easily accommodate working with Africans. It has been practised by psychotherapists of African origin with clients of African origin, but is based upon Eurocentric ideas and guidelines for practice. Many African people consider their core values to be uBuntu, rooted in a principle ‘umntu ngumntu ngabantu’ (translated as ‘a human being is a human being because of other human beings’). Some important features of uBuntu are interdependence, respect, spirituality and the primacy of communality as an approach to life. Some of the ways in which these impact on daily functioning are not foregrounded by adherence to Western principles. The use of only Eurocentric principles when working with clients of African origin may thus not lead to the desired outcomes in psychotherapy. However, these Eurocentric principles are recognised and enforced by the authoritative bodies in the field of psychology, such as the Health Professions Council of South Africa. A distinction will be made between the more inflexible ethical principles of psychology and the ideas of therapy frames. Therapy frames are not seen as being as rigid as ethical codes and they could be augmented, to be appropriate for the context, particularly in the commonly multicultural settings that are found here. Psychotherapists of African origin are torn between abiding by the ethical principles that they have been taught and practising in the way that they, together with their clients, have been socialised. Abiding by the principles as described in the codes is safe because it does not pose any threat of being sanctioned by the regulator of practice, but clients may be let down and there may be limited success with certain clients. This clash of ideas of ways of practice poses dissonance and many dilemmas among psychotherapists of African origin. Due to the nature of this study, Interpretative Phenomenological Analysis (IPA) was adopted as a suitable methodology, where eight practising amaXhosa psychotherapists were interviewed about their experiences of incorporating uBuntu in their psychotherapy practice. The raw data from initial interviews were analysed and the findings concluded that although psychotherapists were trained in Western ways of practice, they included some practices of uBuntu in their practice as well as upholding some Eurocentric principles that seemed to be helpful for their clientele. Subsequently a summary of the findings were discussed with participants in a focus group setting, where participants endorsed and expanded upon their original responses. With the above in mind, a psychotherapy model called uBuntu-Centred Psychotherapy was created, which reflects the principles and therapy frames that have been found to be useful in treating clients of African origin. This modality is more congruent with the worldviews and style of living of many South Africans, in the post-apartheid era. It embraces some Eurocentric principles that are relevant for Africans, while it is embedded in the phenomena and way of life reflected in uBuntu, a predominant mode of functioning for the group that was the focus of this study, the amaXhosa. The study ends by making recommendations for practice, as well as highlighting the need for further and more extensive research to contribute to the project of Africanising psychotherapy.
- Full Text:
- Date Issued: 2020
An investigation of the link between Financial sector development and economic growth in Zimbabwe from 1980 -2016
- Authors: Machokoto, Sydney
- Date: 2020
- Subjects: Financial institutions-- Zimbambwe , Economic growth, development,planning -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49894 , vital:41814
- Description: This study investigated the link between financial sector development and economic growth in Zimbabwe from 1980 to 2016 using the Auto Regressive Distributed Lag model. Market capitalization as a ratio of gross domestic product (GDP), bank credit to the private sector as a ratio of GDP and financial assets of microfinance as a ratio of GDP were used as proxy variables for financial sector development. Economic growth was measured by real GDP. The Granger causality test indicated bi-directional causality between access to financial services and economic growth in Zimbabwe in the long run. Market capitalization and bank credit to the private sector did not Granger cause economic growth in Zimbabwe. It was recommended that the government should promote the functioning of the capital market as it is the conduit for providing long term capital to businesses. Bank credit to the private sector was found to be statistically significant. It was recommended that the government should promote decentralization of the banking sector to rural areas. The proxy variables of financial development used were statistically significant in influencing economic growth. The findings from the study led to the recommendation to open additional microfinance companies in remote areas and to increase the supply of financial services and products. Empirical evidence indicates that the link between financial development and economic growth depends on the proxy variables of financial sector development used in econometric modelling. The model was tested for heteroscedasticity, serial correlation, stability and normality. The econometric tests conducted were all satisfactory. This made the model ideal for policy formulation and recommendation.
- Full Text:
- Date Issued: 2020
- Authors: Machokoto, Sydney
- Date: 2020
- Subjects: Financial institutions-- Zimbambwe , Economic growth, development,planning -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49894 , vital:41814
- Description: This study investigated the link between financial sector development and economic growth in Zimbabwe from 1980 to 2016 using the Auto Regressive Distributed Lag model. Market capitalization as a ratio of gross domestic product (GDP), bank credit to the private sector as a ratio of GDP and financial assets of microfinance as a ratio of GDP were used as proxy variables for financial sector development. Economic growth was measured by real GDP. The Granger causality test indicated bi-directional causality between access to financial services and economic growth in Zimbabwe in the long run. Market capitalization and bank credit to the private sector did not Granger cause economic growth in Zimbabwe. It was recommended that the government should promote the functioning of the capital market as it is the conduit for providing long term capital to businesses. Bank credit to the private sector was found to be statistically significant. It was recommended that the government should promote decentralization of the banking sector to rural areas. The proxy variables of financial development used were statistically significant in influencing economic growth. The findings from the study led to the recommendation to open additional microfinance companies in remote areas and to increase the supply of financial services and products. Empirical evidence indicates that the link between financial development and economic growth depends on the proxy variables of financial sector development used in econometric modelling. The model was tested for heteroscedasticity, serial correlation, stability and normality. The econometric tests conducted were all satisfactory. This made the model ideal for policy formulation and recommendation.
- Full Text:
- Date Issued: 2020
Analysing emergent time within an isolated Universe through the application of interactions in the conditional probability approach
- Authors: Bryan, Kate Louise Halse
- Date: 2020
- Subjects: Space and time , Quantum gravity , Quantum theory , Relativity (Physics)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146676 , vital:38547
- Description: Time remains a frequently discussed issue in physics and philosophy. One interpretation of growing popularity is the ‘timeless’ view which states that our experience of time is only an illusion. The isolated Universe model, provided by the Wheeler-DeWitt equation, supports this interpretation by describing time using clocks in the conditional probability interpretation (CPI). However, the CPI customarily dismisses interaction effects as negligible creating a potential blind spot which overlooks the potential influence of interaction effects. Accounting for interactions opens up a new avenue of analysis and a potential challenge to the interpretation of time. In aid of our assessment of the impact interaction effects have on the CPI, we present rudimentary definitions of time and its associated concepts. Defined in a minimalist manner, time is argued to require a postulate of causality as a means of accounting for temporal ordering in physical theories. Several of these theories are discussed here in terms of their respective approaches to time and, despite their differences, there are indications that the accounts of time are unified in a more fundamental theory. An analytic analysis of the CPI, incorporating two different clock choices, and a qualitative analysis both confirm that interactions have a necessary role within the CPI. The consequence of removing interactions is a maximised uncertainty in any measurement of the clock and a restriction to a two-state system, as indicated by the results of the toy models and qualitative argument respectively. The philosophical implication is that we are not restricted to the timeless view since including interactions as agents of causal interventions between systems provides an account of time as a real phenomenon. This result highlights the reliance on a postulate of causality which forms a pressing problem in explaining our experience of time.
- Full Text:
- Date Issued: 2020
- Authors: Bryan, Kate Louise Halse
- Date: 2020
- Subjects: Space and time , Quantum gravity , Quantum theory , Relativity (Physics)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146676 , vital:38547
- Description: Time remains a frequently discussed issue in physics and philosophy. One interpretation of growing popularity is the ‘timeless’ view which states that our experience of time is only an illusion. The isolated Universe model, provided by the Wheeler-DeWitt equation, supports this interpretation by describing time using clocks in the conditional probability interpretation (CPI). However, the CPI customarily dismisses interaction effects as negligible creating a potential blind spot which overlooks the potential influence of interaction effects. Accounting for interactions opens up a new avenue of analysis and a potential challenge to the interpretation of time. In aid of our assessment of the impact interaction effects have on the CPI, we present rudimentary definitions of time and its associated concepts. Defined in a minimalist manner, time is argued to require a postulate of causality as a means of accounting for temporal ordering in physical theories. Several of these theories are discussed here in terms of their respective approaches to time and, despite their differences, there are indications that the accounts of time are unified in a more fundamental theory. An analytic analysis of the CPI, incorporating two different clock choices, and a qualitative analysis both confirm that interactions have a necessary role within the CPI. The consequence of removing interactions is a maximised uncertainty in any measurement of the clock and a restriction to a two-state system, as indicated by the results of the toy models and qualitative argument respectively. The philosophical implication is that we are not restricted to the timeless view since including interactions as agents of causal interventions between systems provides an account of time as a real phenomenon. This result highlights the reliance on a postulate of causality which forms a pressing problem in explaining our experience of time.
- Full Text:
- Date Issued: 2020
Application of In Vitro Release Testing (IVRT) and a dermatopharmacokinetic approach (tape stripping) for the assessment of Metronidazole topical formulations
- Rath, Seeprarani Prabirkumar
- Authors: Rath, Seeprarani Prabirkumar
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164617 , vital:41148 , doi:10.21504/10962/164617
- Description: Thesis (PhD)--Rhodes University, Faculty of Pharmacy, Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020
- Authors: Rath, Seeprarani Prabirkumar
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164617 , vital:41148 , doi:10.21504/10962/164617
- Description: Thesis (PhD)--Rhodes University, Faculty of Pharmacy, Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020
Application of machine learning, molecular modelling and structural data mining against antiretroviral drug resistance in HIV-1
- Sheik Amamuddy, Olivier Serge André
- Authors: Sheik Amamuddy, Olivier Serge André
- Date: 2020
- Subjects: Machine learning , Molecules -- Models , Data mining , Neural networks (Computer science) , Antiretroviral agents , Protease inhibitors , Drug resistance , Multidrug resistance , Molecular dynamics , Renin-angiotensin system , HIV (Viruses) -- South Africa , HIV (Viruses) -- Social aspects -- South Africa , South African Natural Compounds Database
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115964 , vital:34282
- Description: Millions are affected with the Human Immunodeficiency Virus (HIV) world wide, even though the death toll is on the decline. Antiretrovirals (ARVs), more specifically protease inhibitors have shown tremendous success since their introduction into therapy since the mid 1990’s by slowing down progression to the Acquired Immune Deficiency Syndrome (AIDS). However, Drug Resistance Mutations (DRMs) are constantly selected for due to viral adaptation, making drugs less effective over time. The current challenge is to manage the infection optimally with a limited set of drugs, with differing associated levels of toxicities in the face of a virus that (1) exists as a quasispecies, (2) may transmit acquired DRMs to drug-naive individuals and (3) that can manifest class-wide resistance due to similarities in design. The presence of latent reservoirs, unawareness of infection status, education and various socio-economic factors make the problem even more complex. Adequate timing and choice of drug prescription together with treatment adherence are very important as drug toxicities, drug failure and sub-optimal treatment regimens leave room for further development of drug resistance. While CD4 cell count and the determination of viral load from patients in resource-limited settings are very helpful to track how well a patient’s immune system is able to keep the virus in check, they can be lengthy in determining whether an ARV is effective. Phenosense assay kits answer this problem using viruses engineered to contain the patient sequences and evaluating their growth in the presence of different ARVs, but this can be expensive and too involved for routine checks. As a cheaper and faster alternative, genotypic assays provide similar information from HIV pol sequences obtained from blood samples, inferring ARV efficacy on the basis of drug resistance mutation patterns. However, these are inherently complex and the various methods of in silico prediction, such as Geno2pheno, REGA and Stanford HIVdb do not always agree in every case, even though this gap decreases as the list of resistance mutations is updated. A major gap in HIV treatment is that the information used for predicting drug resistance is mainly computed from data containing an overwhelming majority of B subtype HIV, when these only comprise about 12% of the worldwide HIV infections. In addition to growing evidence that drug resistance is subtype-related, it is intuitive to hypothesize that as subtyping is a phylogenetic classification, the more divergent a subtype is from the strains used in training prediction models, the less their resistance profiles would correlate. For the aforementioned reasons, we used a multi-faceted approach to attack the virus in multiple ways. This research aimed to (1) improve resistance prediction methods by focusing solely on the available subtype, (2) mine structural information pertaining to resistance in order to find any exploitable weak points and increase knowledge of the mechanistic processes of drug resistance in HIV protease. Finally, (3) we screen for protease inhibitors amongst a database of natural compounds [the South African natural compound database (SANCDB)] to find molecules or molecular properties usable to come up with improved inhibition against the drug target. In this work, structural information was mined using the Anisotropic Network Model, Dynamics Cross-Correlation, Perturbation Response Scanning, residue contact network analysis and the radius of gyration. These methods failed to give any resistance-associated patterns in terms of natural movement, internal correlated motions, residue perturbation response, relational behaviour and global compaction respectively. Applications of drug docking, homology-modelling and energy minimization for generating features suitable for machine-learning were not very promising, and rather suggest that the value of binding energies by themselves from Vina may not be very reliable quantitatively. All these failures lead to a refinement that resulted in a highly sensitive statistically-guided network construction and analysis, which leads to key findings in the early dynamics associated with resistance across all PI drugs. The latter experiment unravelled a conserved lateral expansion motion occurring at the flap elbows, and an associated contraction that drives the base of the dimerization domain towards the catalytic site’s floor in the case of drug resistance. Interestingly, we found that despite the conserved movement, bond angles were degenerate. Alongside, 16 Artificial Neural Network models were optimised for HIV proteases and reverse transcriptase inhibitors, with performances on par with Stanford HIVdb. Finally, we prioritised 9 compounds with potential protease inhibitory activity using virtual screening and molecular dynamics (MD) to additionally suggest a promising modification to one of the compounds. This yielded another molecule inhibiting equally well both opened and closed receptor target conformations, whereby each of the compounds had been selected against an array of multi-drug-resistant receptor variants. While a main hurdle was a lack of non-B subtype data, our findings, especially from the statistically-guided network analysis, may extrapolate to a certain extent to them as the level of conservation was very high within subtype B, despite all the present variations. This network construction method lays down a sensitive approach for analysing a pair of alternate phenotypes for which complex patterns prevail, given a sufficient number of experimental units. During the course of research a weighted contact mapping tool was developed to compare renin-angiotensinogen variants and packaged as part of the MD-TASK tool suite. Finally the functionality, compatibility and performance of the MODE-TASK tool were evaluated and confirmed for both Python2.7.x and Python3.x, for the analysis of normals modes from single protein structures and essential modes from MD trajectories. These techniques and tools collectively add onto the conventional means of MD analysis.
- Full Text:
- Date Issued: 2020
- Authors: Sheik Amamuddy, Olivier Serge André
- Date: 2020
- Subjects: Machine learning , Molecules -- Models , Data mining , Neural networks (Computer science) , Antiretroviral agents , Protease inhibitors , Drug resistance , Multidrug resistance , Molecular dynamics , Renin-angiotensin system , HIV (Viruses) -- South Africa , HIV (Viruses) -- Social aspects -- South Africa , South African Natural Compounds Database
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115964 , vital:34282
- Description: Millions are affected with the Human Immunodeficiency Virus (HIV) world wide, even though the death toll is on the decline. Antiretrovirals (ARVs), more specifically protease inhibitors have shown tremendous success since their introduction into therapy since the mid 1990’s by slowing down progression to the Acquired Immune Deficiency Syndrome (AIDS). However, Drug Resistance Mutations (DRMs) are constantly selected for due to viral adaptation, making drugs less effective over time. The current challenge is to manage the infection optimally with a limited set of drugs, with differing associated levels of toxicities in the face of a virus that (1) exists as a quasispecies, (2) may transmit acquired DRMs to drug-naive individuals and (3) that can manifest class-wide resistance due to similarities in design. The presence of latent reservoirs, unawareness of infection status, education and various socio-economic factors make the problem even more complex. Adequate timing and choice of drug prescription together with treatment adherence are very important as drug toxicities, drug failure and sub-optimal treatment regimens leave room for further development of drug resistance. While CD4 cell count and the determination of viral load from patients in resource-limited settings are very helpful to track how well a patient’s immune system is able to keep the virus in check, they can be lengthy in determining whether an ARV is effective. Phenosense assay kits answer this problem using viruses engineered to contain the patient sequences and evaluating their growth in the presence of different ARVs, but this can be expensive and too involved for routine checks. As a cheaper and faster alternative, genotypic assays provide similar information from HIV pol sequences obtained from blood samples, inferring ARV efficacy on the basis of drug resistance mutation patterns. However, these are inherently complex and the various methods of in silico prediction, such as Geno2pheno, REGA and Stanford HIVdb do not always agree in every case, even though this gap decreases as the list of resistance mutations is updated. A major gap in HIV treatment is that the information used for predicting drug resistance is mainly computed from data containing an overwhelming majority of B subtype HIV, when these only comprise about 12% of the worldwide HIV infections. In addition to growing evidence that drug resistance is subtype-related, it is intuitive to hypothesize that as subtyping is a phylogenetic classification, the more divergent a subtype is from the strains used in training prediction models, the less their resistance profiles would correlate. For the aforementioned reasons, we used a multi-faceted approach to attack the virus in multiple ways. This research aimed to (1) improve resistance prediction methods by focusing solely on the available subtype, (2) mine structural information pertaining to resistance in order to find any exploitable weak points and increase knowledge of the mechanistic processes of drug resistance in HIV protease. Finally, (3) we screen for protease inhibitors amongst a database of natural compounds [the South African natural compound database (SANCDB)] to find molecules or molecular properties usable to come up with improved inhibition against the drug target. In this work, structural information was mined using the Anisotropic Network Model, Dynamics Cross-Correlation, Perturbation Response Scanning, residue contact network analysis and the radius of gyration. These methods failed to give any resistance-associated patterns in terms of natural movement, internal correlated motions, residue perturbation response, relational behaviour and global compaction respectively. Applications of drug docking, homology-modelling and energy minimization for generating features suitable for machine-learning were not very promising, and rather suggest that the value of binding energies by themselves from Vina may not be very reliable quantitatively. All these failures lead to a refinement that resulted in a highly sensitive statistically-guided network construction and analysis, which leads to key findings in the early dynamics associated with resistance across all PI drugs. The latter experiment unravelled a conserved lateral expansion motion occurring at the flap elbows, and an associated contraction that drives the base of the dimerization domain towards the catalytic site’s floor in the case of drug resistance. Interestingly, we found that despite the conserved movement, bond angles were degenerate. Alongside, 16 Artificial Neural Network models were optimised for HIV proteases and reverse transcriptase inhibitors, with performances on par with Stanford HIVdb. Finally, we prioritised 9 compounds with potential protease inhibitory activity using virtual screening and molecular dynamics (MD) to additionally suggest a promising modification to one of the compounds. This yielded another molecule inhibiting equally well both opened and closed receptor target conformations, whereby each of the compounds had been selected against an array of multi-drug-resistant receptor variants. While a main hurdle was a lack of non-B subtype data, our findings, especially from the statistically-guided network analysis, may extrapolate to a certain extent to them as the level of conservation was very high within subtype B, despite all the present variations. This network construction method lays down a sensitive approach for analysing a pair of alternate phenotypes for which complex patterns prevail, given a sufficient number of experimental units. During the course of research a weighted contact mapping tool was developed to compare renin-angiotensinogen variants and packaged as part of the MD-TASK tool suite. Finally the functionality, compatibility and performance of the MODE-TASK tool were evaluated and confirmed for both Python2.7.x and Python3.x, for the analysis of normals modes from single protein structures and essential modes from MD trajectories. These techniques and tools collectively add onto the conventional means of MD analysis.
- Full Text:
- Date Issued: 2020
Applied phylogeography : mapping the genetic resource of Honeybush across the Cape Floristic Region
- Authors: Galuszynski, Nicholas C
- Date: 2020
- Subjects: Phylogeography -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46771 , vital:39655
- Description: Aim: Honeybush tea is a herbal infusion made from members of the Cape Floristic Region (CFR) endemic Cyclopia Vent. Consting of 21 extant species, six are anthropogenically redistributed across the CFR for Honeybush cultivation. However, with no information regarding the distribution and levels of genetic diversity among wild Honeybush populations, anthropogenic translocation of cultivated genotypes may risk disrupting natural genetic diversity patterns. In this thesis, an applied phylogeographic approach is used to provide baseline insights into the spatial structuring of Honeybush genetic diversity. Location: The Cape Floristic Region (CFR), located along the southern Cape of South Africa. Methods: Spatial structuring of evolutionary lineages within Cyclopia are explored at a genus level using data generated from the combination of Anchored Hybrid Enrichment library preparation and high through put sequencing. A High Resolution Melt analysis (HRM) toolkit is then developed to screen haplotype variation across three non-coding chloroplast loci. This HRM toolkit coupled with haplotype confirmation Sanger sequencing is then applied to describe the spatial structuring of genetic diversity in wild populations for two Honeybush species (C. intermedia and C. subternata) and to compare genetic diversity among wild and cultivated populations of three Honeybush species (C. intermedia, C. subternata, and C. longifolia). A reanalysis of published phylogeographic data focusing on CFR plant taxa is used to test if phylogeographic breaks occur across the boundaries among adjacent Centers of Endemism (CoEs). Finally, the low-copy nuclear data set generated via AHE and high throughput sequencing is summarized. Results: Phylogeographic structuring was detected at the inter- and intraspecific levels in Cyclopia. The genus level analysis revealed a strong phylogenetic split between western CFR and eastern CFR endemic species in the nuclear and chloroplast genomes. At the intraspecific level, HRM proved to be a high throughput and accurate tool for haplotype detection, revealing phylogeographic structuring of genetic diversity in C.intermediaand C.subternata. This genetic diversity and structuring was not detected in cultivated Honeybush populations, which appear to have originated from a small number of founding individuals and have experienced a genetic bottleneck. Spatial structuring of genetic lineages is common among CFR plant taxa and the reanalysis of existing data found a significant trend for phylogeographic breaks tooccuracrosstheboundariesamongadjacentCoEs. Finally, over200000baseswere sequenced across 445 low-copy nuclear loci for 14 Cyclopia species. Conclusions: This thesis provides important baseline information on the spatial distribution of wild Honeybush genetic diversity. Phylogeographic structuring is present in wild Honeybush populations. This however is not accounted for in cultivated populations, which may place wild genetic diversity at risk of being disrupted if geneflow among wild and cultivated populations occurs. The results from this thesis should therefore be used to develop precautionary guidelines for the anthropogenic redistribution of Honeybush genetic material for cultivation. Furthermore, the novel insights into regional patterns of phylogeohraphic structuring of plant populations should encourage more efficient and hypothesis driven sampling designs in future phylogeographic work in the CFR. The high throughput sequence data generated in this thesis should transform Cyclopia to a model organism for the study of molecular evolution in the CFR.
- Full Text:
- Date Issued: 2020
- Authors: Galuszynski, Nicholas C
- Date: 2020
- Subjects: Phylogeography -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46771 , vital:39655
- Description: Aim: Honeybush tea is a herbal infusion made from members of the Cape Floristic Region (CFR) endemic Cyclopia Vent. Consting of 21 extant species, six are anthropogenically redistributed across the CFR for Honeybush cultivation. However, with no information regarding the distribution and levels of genetic diversity among wild Honeybush populations, anthropogenic translocation of cultivated genotypes may risk disrupting natural genetic diversity patterns. In this thesis, an applied phylogeographic approach is used to provide baseline insights into the spatial structuring of Honeybush genetic diversity. Location: The Cape Floristic Region (CFR), located along the southern Cape of South Africa. Methods: Spatial structuring of evolutionary lineages within Cyclopia are explored at a genus level using data generated from the combination of Anchored Hybrid Enrichment library preparation and high through put sequencing. A High Resolution Melt analysis (HRM) toolkit is then developed to screen haplotype variation across three non-coding chloroplast loci. This HRM toolkit coupled with haplotype confirmation Sanger sequencing is then applied to describe the spatial structuring of genetic diversity in wild populations for two Honeybush species (C. intermedia and C. subternata) and to compare genetic diversity among wild and cultivated populations of three Honeybush species (C. intermedia, C. subternata, and C. longifolia). A reanalysis of published phylogeographic data focusing on CFR plant taxa is used to test if phylogeographic breaks occur across the boundaries among adjacent Centers of Endemism (CoEs). Finally, the low-copy nuclear data set generated via AHE and high throughput sequencing is summarized. Results: Phylogeographic structuring was detected at the inter- and intraspecific levels in Cyclopia. The genus level analysis revealed a strong phylogenetic split between western CFR and eastern CFR endemic species in the nuclear and chloroplast genomes. At the intraspecific level, HRM proved to be a high throughput and accurate tool for haplotype detection, revealing phylogeographic structuring of genetic diversity in C.intermediaand C.subternata. This genetic diversity and structuring was not detected in cultivated Honeybush populations, which appear to have originated from a small number of founding individuals and have experienced a genetic bottleneck. Spatial structuring of genetic lineages is common among CFR plant taxa and the reanalysis of existing data found a significant trend for phylogeographic breaks tooccuracrosstheboundariesamongadjacentCoEs. Finally, over200000baseswere sequenced across 445 low-copy nuclear loci for 14 Cyclopia species. Conclusions: This thesis provides important baseline information on the spatial distribution of wild Honeybush genetic diversity. Phylogeographic structuring is present in wild Honeybush populations. This however is not accounted for in cultivated populations, which may place wild genetic diversity at risk of being disrupted if geneflow among wild and cultivated populations occurs. The results from this thesis should therefore be used to develop precautionary guidelines for the anthropogenic redistribution of Honeybush genetic material for cultivation. Furthermore, the novel insights into regional patterns of phylogeohraphic structuring of plant populations should encourage more efficient and hypothesis driven sampling designs in future phylogeographic work in the CFR. The high throughput sequence data generated in this thesis should transform Cyclopia to a model organism for the study of molecular evolution in the CFR.
- Full Text:
- Date Issued: 2020
Assessment of the microbial quality of various domestic rainwater harvesting systems and the suitability of a nano based treatment method
- Authors: Malema, Mokaba Shirley
- Date: 2020
- Language: English
- Type: thesis , text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/110218 , vital:33249 , https://dx.doi.org/10.21504/10962/110218
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Chemistry, 2020.
- Full Text: false
- Date Issued: 2020
- Authors: Malema, Mokaba Shirley
- Date: 2020
- Language: English
- Type: thesis , text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/110218 , vital:33249 , https://dx.doi.org/10.21504/10962/110218
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Chemistry, 2020.
- Full Text: false
- Date Issued: 2020
Attention-deficit/hyperactivity disorder (ADHD) in South Africa: diagnosis and treatment from childhood to adulthood
- Munasur-Naidoo, Ashmitha Premchand
- Authors: Munasur-Naidoo, Ashmitha Premchand
- Date: 2020
- Subjects: Attention-deficit hyperactivity disorder
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46398 , vital:39603
- Description: Background: Historically Attention-Deficit/hyperactivity disorder (ADHD) was, considered to be a condition that affected mainly children. Over a period of time, there has been a greater understanding to recognize that this condition is also present in the adult population. Globally, treatment for adults has been established as is evident from the various guidelines available. In South Africa, however,healthcare is split into the public and private sectors, which results in differences in the extent of diagnosis and treatment for adults with ADHD.Aim: The primary aim of the study was to evaluate ADHD in South Africa from childhood to adulthood and to determine to what extent adults are being diagnosed and treated.Method: This study comprised of two facets, namely, a drug utilization review and a questionnaire survey. The first part comprised of a retrospective drug utilization study evaluating the consumption and cost of medication used in the treatment of ADHD. The questionnaire was undertaken using a survey methodology amongst selected healthcare professionals in South Africa involved in the diagnosis and treatment of adult ADHD. The data generated from this study together with available guidelines was assessed and a proposed framework for the treatment and diagnosis of adult ADHD was developed for use in the South African public healthcare sector. Results: Based on the registered medication available to treat ADHD, the consumption of methylphenidate and atomoxetine in the private healthcare sector using the Intercontinental Marketing Service database from 2013 to 2016was established. Despite the controversy regarding stimulant medication, methylphenidate was shown to be the medication of choice in South Africa. The consumption of methylphenidate (95.85%) was higher when compared to atomoxetine (4.15%) in 2013 and very slight changes were observed in 2016 were the consumption was 96.40% and 3.60%, respectively. Similarly, over a four-year period, the spend on ADHD medication increased in 2013 to 2016 by 62.63%. Furthermore, the market share for ADHD is dominated by extended-release methylphenidate tablets (59.53%). The questionnaire survey amongst selected healthcare professionals in South Africa involved in the diagnosis and treatment of adult ADHDhighlighted the tools used for diagnosis, pharmacological and non-pharmacological treatment options, which treatment has been found to be most successful, difference in treatment between genders, incorporation of supplementation into the management of patients, difficulties experienced by patients and which co-morbid conditions were also prevalent with ADHD. Based on the data collated in this study and an evaluation of the available guidelines, a framework for treatment of adult patients in the public healthcare sector has been proposed for South Africa at a provincial and national level. Conclusion: In South Africa treatment for ADHD is increasing in the private healthcare sector. The cost and consumption of methylphenidate and atomoxetine has risen over a short period. The treatment of adults in the private sector has also garnered interest, however, the public sector has not yet published guidelines enabling access to diagnosis and treatment for these adult patients. Given the chronic, costly, and debilitating nature of this condition more needs to be done to assist those affected by it. Further studies in this area of neuropsychiatry in South Africa is required to enable access to diagnosis and treatment in the public healthcare sector.
- Full Text:
- Date Issued: 2020
- Authors: Munasur-Naidoo, Ashmitha Premchand
- Date: 2020
- Subjects: Attention-deficit hyperactivity disorder
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46398 , vital:39603
- Description: Background: Historically Attention-Deficit/hyperactivity disorder (ADHD) was, considered to be a condition that affected mainly children. Over a period of time, there has been a greater understanding to recognize that this condition is also present in the adult population. Globally, treatment for adults has been established as is evident from the various guidelines available. In South Africa, however,healthcare is split into the public and private sectors, which results in differences in the extent of diagnosis and treatment for adults with ADHD.Aim: The primary aim of the study was to evaluate ADHD in South Africa from childhood to adulthood and to determine to what extent adults are being diagnosed and treated.Method: This study comprised of two facets, namely, a drug utilization review and a questionnaire survey. The first part comprised of a retrospective drug utilization study evaluating the consumption and cost of medication used in the treatment of ADHD. The questionnaire was undertaken using a survey methodology amongst selected healthcare professionals in South Africa involved in the diagnosis and treatment of adult ADHD. The data generated from this study together with available guidelines was assessed and a proposed framework for the treatment and diagnosis of adult ADHD was developed for use in the South African public healthcare sector. Results: Based on the registered medication available to treat ADHD, the consumption of methylphenidate and atomoxetine in the private healthcare sector using the Intercontinental Marketing Service database from 2013 to 2016was established. Despite the controversy regarding stimulant medication, methylphenidate was shown to be the medication of choice in South Africa. The consumption of methylphenidate (95.85%) was higher when compared to atomoxetine (4.15%) in 2013 and very slight changes were observed in 2016 were the consumption was 96.40% and 3.60%, respectively. Similarly, over a four-year period, the spend on ADHD medication increased in 2013 to 2016 by 62.63%. Furthermore, the market share for ADHD is dominated by extended-release methylphenidate tablets (59.53%). The questionnaire survey amongst selected healthcare professionals in South Africa involved in the diagnosis and treatment of adult ADHDhighlighted the tools used for diagnosis, pharmacological and non-pharmacological treatment options, which treatment has been found to be most successful, difference in treatment between genders, incorporation of supplementation into the management of patients, difficulties experienced by patients and which co-morbid conditions were also prevalent with ADHD. Based on the data collated in this study and an evaluation of the available guidelines, a framework for treatment of adult patients in the public healthcare sector has been proposed for South Africa at a provincial and national level. Conclusion: In South Africa treatment for ADHD is increasing in the private healthcare sector. The cost and consumption of methylphenidate and atomoxetine has risen over a short period. The treatment of adults in the private sector has also garnered interest, however, the public sector has not yet published guidelines enabling access to diagnosis and treatment for these adult patients. Given the chronic, costly, and debilitating nature of this condition more needs to be done to assist those affected by it. Further studies in this area of neuropsychiatry in South Africa is required to enable access to diagnosis and treatment in the public healthcare sector.
- Full Text:
- Date Issued: 2020