Symmetry and asymmetry in electrocatalysis: enhancing the electrocatalytic activity of phthalocyanines through synergy with doped graphene quantum dots
- Nkhahle, Reitumetse Precious
- Authors: Nkhahle, Reitumetse Precious
- Date: 2020
- Subjects: Phthalocyanines , Quantum dots , Graphene
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/117585 , vital:34529
- Description: An exploration on the enhancement of the electrocatalytic activity of phthalocyanines (Pcs) through coupling with a series of graphene quantum dots (GQDs) is undertaken. The preliminary studies using symmetrical Pcs, a cobalt and an iron chloride tetra substituted diethylaminophenoxy Pc (complexes 1 and 2), for the electro-oxidation of nitrite revealed through the various sequential modifications that doped GQDs fare better than their pristine counterparts with respect to improving the electrocatalytic behaviour of Pcs, in particular, the nitrogen-doped GQDs (NGQDs). Following up on this, a series of asymmetric Pc complexes; 2,9,16-tris-(4-tert-butylphenoxy) mono carboxyphenoxy phthalocyanato cobalt (II) (3), 2,9,16-tris-(4-tert-butylphenoxy) mono aminophenoxy phthalocyanato cobalt (II) (4), 2,9,16-tris-(3-diethylamino)phenoxy) mono carboxyphenoxy phthalocyanato cobalt (II) (5) and 2,9,16-tris-(3-diethylamino)phenoxy) mono aminophenoxy phthalocyanato cobalt (II) (6) was prepared in which push-pull systems were compared to other asymmetric complexes that lack this effect towards the electrocatalytic sensing of hydrazine. All asymmetric complexes (3-6) were π-stacked to the NGQDs while those with an NH2 group (4 and 6), were also covalently linked to the NGQDs. These complexes and their corresponding conjugates were characterized accordingly and applied as electrocatalysts in the oxidation of hydrazine. The electrochemical studies revealed that π π stacking yields better responses (higher sensitivities and lower limits of detection) than covalent linking because there are less forces acting on the graphene network. Covalent linking introduces both tensile and compressive forces which in turn results in an increase in the ID/IG ratio and that is unfavourable for electrocatalysis. In comparing the electrodes composed of the π-stacked conjugates to those altered through sequential modifications, despite the conditions not being the same, it can be inferred that the magnitude of the electrostatic forces between the Pcs and the GQDs also plays a significant role in electrocatalysis. The π-stacked conjugates, owing to the manner in which they were prepared, have stronger electrostatic forces acting between the Pc and GQDs hence they were able to elicit a better electrochemical response than the sequentially modified electrodes. In addition to that, it appears that asymmetric Pcs are better electrocatalysts in comparison to the symmetric Pcs.
- Full Text:
- Date Issued: 2020
- Authors: Nkhahle, Reitumetse Precious
- Date: 2020
- Subjects: Phthalocyanines , Quantum dots , Graphene
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/117585 , vital:34529
- Description: An exploration on the enhancement of the electrocatalytic activity of phthalocyanines (Pcs) through coupling with a series of graphene quantum dots (GQDs) is undertaken. The preliminary studies using symmetrical Pcs, a cobalt and an iron chloride tetra substituted diethylaminophenoxy Pc (complexes 1 and 2), for the electro-oxidation of nitrite revealed through the various sequential modifications that doped GQDs fare better than their pristine counterparts with respect to improving the electrocatalytic behaviour of Pcs, in particular, the nitrogen-doped GQDs (NGQDs). Following up on this, a series of asymmetric Pc complexes; 2,9,16-tris-(4-tert-butylphenoxy) mono carboxyphenoxy phthalocyanato cobalt (II) (3), 2,9,16-tris-(4-tert-butylphenoxy) mono aminophenoxy phthalocyanato cobalt (II) (4), 2,9,16-tris-(3-diethylamino)phenoxy) mono carboxyphenoxy phthalocyanato cobalt (II) (5) and 2,9,16-tris-(3-diethylamino)phenoxy) mono aminophenoxy phthalocyanato cobalt (II) (6) was prepared in which push-pull systems were compared to other asymmetric complexes that lack this effect towards the electrocatalytic sensing of hydrazine. All asymmetric complexes (3-6) were π-stacked to the NGQDs while those with an NH2 group (4 and 6), were also covalently linked to the NGQDs. These complexes and their corresponding conjugates were characterized accordingly and applied as electrocatalysts in the oxidation of hydrazine. The electrochemical studies revealed that π π stacking yields better responses (higher sensitivities and lower limits of detection) than covalent linking because there are less forces acting on the graphene network. Covalent linking introduces both tensile and compressive forces which in turn results in an increase in the ID/IG ratio and that is unfavourable for electrocatalysis. In comparing the electrodes composed of the π-stacked conjugates to those altered through sequential modifications, despite the conditions not being the same, it can be inferred that the magnitude of the electrostatic forces between the Pcs and the GQDs also plays a significant role in electrocatalysis. The π-stacked conjugates, owing to the manner in which they were prepared, have stronger electrostatic forces acting between the Pc and GQDs hence they were able to elicit a better electrochemical response than the sequentially modified electrodes. In addition to that, it appears that asymmetric Pcs are better electrocatalysts in comparison to the symmetric Pcs.
- Full Text:
- Date Issued: 2020
Towards a capability maturity model for a cyber range
- Authors: Aschmann, Michael Joseph
- Date: 2020
- Subjects: Computer software -- Development , Computer security
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/163142 , vital:41013
- Description: This work describes research undertaken towards the development of a Capability Maturity Model (CMM) for Cyber Ranges (CRs) focused on cyber security. Global cyber security needs are on the rise, and the need for attribution within the cyber domain is of particular concern. This has prompted major efforts to enhance cyber capabilities within organisations to increase their total cyber resilience posture. These efforts include, but are not limited to, the testing of computational devices, networks, and applications, and cyber skills training focused on prevention, detection and cyber attack response. A cyber range allows for the testing of the computational environment. By developing cyber events within a confined virtual or sand-boxed cyber environment, a cyber range can prepare the next generation of cyber security specialists to handle a variety of potential cyber attacks. Cyber ranges have different purposes, each designed to fulfil a different computational testing and cyber training goal; consequently, cyber ranges can vary greatly in the level of variety, capability, maturity and complexity. As cyber ranges proliferate and become more and more valued as tools for cyber security, a method to classify or rate them becomes essential. Yet while a universal criteria for measuring cyber ranges in terms of their capability maturity levels becomes more critical, there are currently very limited resources for researchers aiming to perform this kind of work. For this reason, this work proposes and describes a CMM, designed to give organisations the ability to benchmark the capability maturity of a given cyber range. This research adopted a synthesised approach to the development of a CMM, grounded in prior research and focused on the production of a conceptual model that provides a useful level of abstraction. In order to achieve this goal, the core capability elements of a cyber range are defined with their relative importance, allowing for the development of a proposed classification cyber range levels. An analysis of data gathered during the course of an expert review, together with other research, further supported the development of the conceptual model. In the context of cyber range capability, classification will include the ability of the cyber range to perform its functions optimally with different core capability elements, focusing on the Measurement of Capability (MoC) with its elements, namely effect, performance and threat ability. Cyber range maturity can evolve over time and can be defined through the Measurement of Maturity (MoM) with its elements, namely people, processes, technology. The combination of these measurements utilising the CMM for a CR determines the capability maturity level of a CR. The primary outcome of this research is the proposed level-based CMM framework for a cyber range, developed using adopted and synthesised CMMs, the analysis of an expert review, and the mapping of the results.
- Full Text:
- Date Issued: 2020
- Authors: Aschmann, Michael Joseph
- Date: 2020
- Subjects: Computer software -- Development , Computer security
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/163142 , vital:41013
- Description: This work describes research undertaken towards the development of a Capability Maturity Model (CMM) for Cyber Ranges (CRs) focused on cyber security. Global cyber security needs are on the rise, and the need for attribution within the cyber domain is of particular concern. This has prompted major efforts to enhance cyber capabilities within organisations to increase their total cyber resilience posture. These efforts include, but are not limited to, the testing of computational devices, networks, and applications, and cyber skills training focused on prevention, detection and cyber attack response. A cyber range allows for the testing of the computational environment. By developing cyber events within a confined virtual or sand-boxed cyber environment, a cyber range can prepare the next generation of cyber security specialists to handle a variety of potential cyber attacks. Cyber ranges have different purposes, each designed to fulfil a different computational testing and cyber training goal; consequently, cyber ranges can vary greatly in the level of variety, capability, maturity and complexity. As cyber ranges proliferate and become more and more valued as tools for cyber security, a method to classify or rate them becomes essential. Yet while a universal criteria for measuring cyber ranges in terms of their capability maturity levels becomes more critical, there are currently very limited resources for researchers aiming to perform this kind of work. For this reason, this work proposes and describes a CMM, designed to give organisations the ability to benchmark the capability maturity of a given cyber range. This research adopted a synthesised approach to the development of a CMM, grounded in prior research and focused on the production of a conceptual model that provides a useful level of abstraction. In order to achieve this goal, the core capability elements of a cyber range are defined with their relative importance, allowing for the development of a proposed classification cyber range levels. An analysis of data gathered during the course of an expert review, together with other research, further supported the development of the conceptual model. In the context of cyber range capability, classification will include the ability of the cyber range to perform its functions optimally with different core capability elements, focusing on the Measurement of Capability (MoC) with its elements, namely effect, performance and threat ability. Cyber range maturity can evolve over time and can be defined through the Measurement of Maturity (MoM) with its elements, namely people, processes, technology. The combination of these measurements utilising the CMM for a CR determines the capability maturity level of a CR. The primary outcome of this research is the proposed level-based CMM framework for a cyber range, developed using adopted and synthesised CMMs, the analysis of an expert review, and the mapping of the results.
- Full Text:
- Date Issued: 2020
A comparative analysis of social media brand image of insurance companies in South Africa: a longitudinal study
- Authors: Gudu, Daniel
- Date: 2020
- Subjects: Social media -- South Africa , Internet marketing -- South Africa , Chernoff faces , Ínsurance companies -- South Africa -- Marketing , Insurance companies -- South Africa -- Case studies , Multivariate analysis -- Graphic methods
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/144277 , vital:38327
- Description: Social media is changing the way business is conducted. Almost five billion videos are watched on YouTube every single day. Social media has an extensive worldwide presence. Out of the total global population of over 7,5 billion people, over 4 billion are internet users. Of these, over 3 billion are active on social media. Social media is very influential in today's decision-making processes. Businesses must integrate social media into their strategies. The purpose of this research was to investigate the use of a novel method, Chernoff Faces, to assess and compare the social media brand images of six insurance companies in South Africa based on social conversation measurement. The intention of research was towards observing existing situations at hand and pointing out the game changers that can provide the industry with a new leap. Social media are multidimensional and understanding them requires tracking different measures simultaneously. Integrating social media into a communication strategy leads to a problem in finding the best way to portray and communicate multivariate data. It is essential to find the best way to represent and transmit the data so that marketing executives can quickly and easily monitor changes in brand images. Previous studies have successfully proved the possibility of using this method to gauge a "snapshot in time." This study took the concept further by closely monitoring the results for a set of brands over a period to account for the dynamic nature of social media. Accordingly, the study was a longitudinal study of 30 days. Data on the insurance companies was collected from Social Mention, a social media search and analysis platform that aggregates user-generated content into a single stream of information. A tool in the statistical software Stata, Chernoff's faces, was used to analyse the results by generating facial expressions to the metrics associated with the social mentions of each of the insurance companies. The resulting facial expressions were then analysed to recognise the more favourable and stable brands and those that need appropriate risk management. Managing Social Media is challenging as managers must always keep it as positive as possible. Brand managers, therefore, need a better tool to gauge the mood in social media conversations due to the fast-changing nature of social media and the importance of social media to business especially insurance.
- Full Text:
- Date Issued: 2020
- Authors: Gudu, Daniel
- Date: 2020
- Subjects: Social media -- South Africa , Internet marketing -- South Africa , Chernoff faces , Ínsurance companies -- South Africa -- Marketing , Insurance companies -- South Africa -- Case studies , Multivariate analysis -- Graphic methods
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/144277 , vital:38327
- Description: Social media is changing the way business is conducted. Almost five billion videos are watched on YouTube every single day. Social media has an extensive worldwide presence. Out of the total global population of over 7,5 billion people, over 4 billion are internet users. Of these, over 3 billion are active on social media. Social media is very influential in today's decision-making processes. Businesses must integrate social media into their strategies. The purpose of this research was to investigate the use of a novel method, Chernoff Faces, to assess and compare the social media brand images of six insurance companies in South Africa based on social conversation measurement. The intention of research was towards observing existing situations at hand and pointing out the game changers that can provide the industry with a new leap. Social media are multidimensional and understanding them requires tracking different measures simultaneously. Integrating social media into a communication strategy leads to a problem in finding the best way to portray and communicate multivariate data. It is essential to find the best way to represent and transmit the data so that marketing executives can quickly and easily monitor changes in brand images. Previous studies have successfully proved the possibility of using this method to gauge a "snapshot in time." This study took the concept further by closely monitoring the results for a set of brands over a period to account for the dynamic nature of social media. Accordingly, the study was a longitudinal study of 30 days. Data on the insurance companies was collected from Social Mention, a social media search and analysis platform that aggregates user-generated content into a single stream of information. A tool in the statistical software Stata, Chernoff's faces, was used to analyse the results by generating facial expressions to the metrics associated with the social mentions of each of the insurance companies. The resulting facial expressions were then analysed to recognise the more favourable and stable brands and those that need appropriate risk management. Managing Social Media is challenging as managers must always keep it as positive as possible. Brand managers, therefore, need a better tool to gauge the mood in social media conversations due to the fast-changing nature of social media and the importance of social media to business especially insurance.
- Full Text:
- Date Issued: 2020
Disco
- Authors: Trantraal, Nathan
- Date: 2020
- Subjects: South African fiction (English) -- 21st century , South African poetry (English) -- 21st century , Afrikaans fiction -- 21st century , Afrikaans poetry -- 21st century
- Language: Afrikaans , English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145217 , vital:38419
- Description: Creative writing portfolio.
- Full Text:
- Date Issued: 2020
- Authors: Trantraal, Nathan
- Date: 2020
- Subjects: South African fiction (English) -- 21st century , South African poetry (English) -- 21st century , Afrikaans fiction -- 21st century , Afrikaans poetry -- 21st century
- Language: Afrikaans , English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145217 , vital:38419
- Description: Creative writing portfolio.
- Full Text:
- Date Issued: 2020
Guidelines for the user interface design of electronic medical records in optometry
- Authors: Nathoo, Dina
- Date: 2020
- Subjects: User interfaces (Computer systems) , Medical records -- Data processing , Optometry -- South Africa -- Eastern Cape , System design , Workflow management systems
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/148782 , vital:38773
- Description: With the prevalence of digitalisation in the medical industry, e-health systems have largely replaced the traditional paper-based recording methods. At the centre of these e-health systems are Electronic Health Records (EHRs) and Electronic Medical Records (EMRs), whose benefits significantly improve physician workflows. However, provision for user interface designs (UIDs) of these systems have been so poor that they have severely hindered physician usability, disrupted their workflows and risked patient safety. UID and usability guidelines have been provided, but have been very high level and general, mostly suitable for EHRs (which are used in general practices and hospitals). These guidelines have thus been ineffective in applicability for EMRs, which are typically used in niche medical environments. Within the niche field of Optometry, physicians experience disrupted workflows as a result of poor EMR UID and usability, of which EMR guidelines to improve these challenges are scarce. Hence, the need for this research arose, aiming to create UID guidelines for EMRs in Optometry, which will help improve the usability of the optometrists’ EMR. The main research question was successfully answered to produce the set of UID Guidelines for EMRs in Optometry, which includes guidelines built upon from literature and made contextually relevant, as well as some new additions, which are more patient focused. Design Science Research (DSR) was chosen as a suitable approach, and the phased Design Science Research Process Model (DSRPM) was used to guide this research. A literature review was conducted, including EHR and EMR, usability, UIDs, Optometry, related fields, and studies previously conducted to provide guidelines, frameworks and models. The review also included studying usability problems reported on the systems and the methods to overcome them. Task Analysis (TA) was used to observe and understand the optometrists’ workflows and their interactions with their EMRs during patient appointments, also identifying EMR problem areas. To address these problems, Focus Groups (FGs) were used to brainstorm solutions in the form of EMR UID features that optometrists’ required to improve their usability. From the literature review, TAs and FGs, proposed guidelines were created. The created guidelines informed the UID of an EMR prototype, which was successfully demonstrated to optometrists during Usability Testing sessions for the evaluation. Surveys were also used for the evaluation. The results proved the guidelines were successful, and were usable, effective, efficient and of good quality. A revised, final set of guidelines was then presented. Future researchers and designers may benefit from the contributions made from this research, which are both theoretical and practical.
- Full Text:
- Date Issued: 2020
- Authors: Nathoo, Dina
- Date: 2020
- Subjects: User interfaces (Computer systems) , Medical records -- Data processing , Optometry -- South Africa -- Eastern Cape , System design , Workflow management systems
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/148782 , vital:38773
- Description: With the prevalence of digitalisation in the medical industry, e-health systems have largely replaced the traditional paper-based recording methods. At the centre of these e-health systems are Electronic Health Records (EHRs) and Electronic Medical Records (EMRs), whose benefits significantly improve physician workflows. However, provision for user interface designs (UIDs) of these systems have been so poor that they have severely hindered physician usability, disrupted their workflows and risked patient safety. UID and usability guidelines have been provided, but have been very high level and general, mostly suitable for EHRs (which are used in general practices and hospitals). These guidelines have thus been ineffective in applicability for EMRs, which are typically used in niche medical environments. Within the niche field of Optometry, physicians experience disrupted workflows as a result of poor EMR UID and usability, of which EMR guidelines to improve these challenges are scarce. Hence, the need for this research arose, aiming to create UID guidelines for EMRs in Optometry, which will help improve the usability of the optometrists’ EMR. The main research question was successfully answered to produce the set of UID Guidelines for EMRs in Optometry, which includes guidelines built upon from literature and made contextually relevant, as well as some new additions, which are more patient focused. Design Science Research (DSR) was chosen as a suitable approach, and the phased Design Science Research Process Model (DSRPM) was used to guide this research. A literature review was conducted, including EHR and EMR, usability, UIDs, Optometry, related fields, and studies previously conducted to provide guidelines, frameworks and models. The review also included studying usability problems reported on the systems and the methods to overcome them. Task Analysis (TA) was used to observe and understand the optometrists’ workflows and their interactions with their EMRs during patient appointments, also identifying EMR problem areas. To address these problems, Focus Groups (FGs) were used to brainstorm solutions in the form of EMR UID features that optometrists’ required to improve their usability. From the literature review, TAs and FGs, proposed guidelines were created. The created guidelines informed the UID of an EMR prototype, which was successfully demonstrated to optometrists during Usability Testing sessions for the evaluation. Surveys were also used for the evaluation. The results proved the guidelines were successful, and were usable, effective, efficient and of good quality. A revised, final set of guidelines was then presented. Future researchers and designers may benefit from the contributions made from this research, which are both theoretical and practical.
- Full Text:
- Date Issued: 2020
Investigating visual literacy development through advertisements: a case of Grade 7 English Language Teaching in Mount Frere District, Eastern Cape
- Authors: Mbuqe, Zolile Patrick
- Date: 2020
- Subjects: Visual literacy , English language -- Study and teaching -- Audio-visual aids , Second language acquisition -- South Africa , English language -- Study and teaching -- Activity programs , Advertising -- Study and teaching , Visual learning , English language -- Study and teaching -- South Africa
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/143458 , vital:38248
- Description: Although the Curriculum and Assessment Policy Statement lists visual literacy as one of the aspects of English First Additional Language in Grades 4-12, many teachers face challenges in teaching it. This study aimed to investigate visual literacy development through advertisements. Drawing on Cultural Historical Activity Theory, this qualitative intervention designed two research phases in which data was collected and analysed. The first phase, a pre-intervention, included lesson observation, analysis of documents and post-lesson semi-structured interviews. Based on Phase One findings and using advertisements as an entry point in developing visual literacy, Phase Two occurred at a change laboratory workshop and engaged eight teachers with the dynamics of meaning making and teaching. This data was analysed using elements of social semiotics and Serafini’s resource practices. The key findings are that despite low visual literacy understanding and practices, rigorous formative intervention indicated advancement in teachers’ understanding of visual literacy. In addition, through this intervention, teachers developed agency in dealing with schooling adversities such as lack of resources and knowledge hence further formative intervention research in visual literacy is recommended for both EFAL subject advisors and teachers.
- Full Text:
- Date Issued: 2020
- Authors: Mbuqe, Zolile Patrick
- Date: 2020
- Subjects: Visual literacy , English language -- Study and teaching -- Audio-visual aids , Second language acquisition -- South Africa , English language -- Study and teaching -- Activity programs , Advertising -- Study and teaching , Visual learning , English language -- Study and teaching -- South Africa
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/143458 , vital:38248
- Description: Although the Curriculum and Assessment Policy Statement lists visual literacy as one of the aspects of English First Additional Language in Grades 4-12, many teachers face challenges in teaching it. This study aimed to investigate visual literacy development through advertisements. Drawing on Cultural Historical Activity Theory, this qualitative intervention designed two research phases in which data was collected and analysed. The first phase, a pre-intervention, included lesson observation, analysis of documents and post-lesson semi-structured interviews. Based on Phase One findings and using advertisements as an entry point in developing visual literacy, Phase Two occurred at a change laboratory workshop and engaged eight teachers with the dynamics of meaning making and teaching. This data was analysed using elements of social semiotics and Serafini’s resource practices. The key findings are that despite low visual literacy understanding and practices, rigorous formative intervention indicated advancement in teachers’ understanding of visual literacy. In addition, through this intervention, teachers developed agency in dealing with schooling adversities such as lack of resources and knowledge hence further formative intervention research in visual literacy is recommended for both EFAL subject advisors and teachers.
- Full Text:
- Date Issued: 2020
Exploring affordances and hindrances when indigenous knowledge is integrated in the topic on waves and sound in a Grade 10 Physical Sciences township class
- Authors: Manyana, Xolani Justice
- Date: 2020
- Subjects: Physical sciences -- Study and teaching (Secondary) -- South Africa , Physical sciences -- Study and teaching (Secondary) -- South Africa -- Case studies , Ethnoscience -- Study and teaching -- South Africa , Schools -- South Africa -- Curricula , Social change
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/142889 , vital:38173
- Description: The lack of interest and hence the decline in the number of learners doing Science in schools, is attributed in part to the decontextualised ways in which Science is taught. As an attempt to address this challenge, the new South African National Curriculum Policy Statement (CAPS) encourages Science teachers to use culturally responsive pedagogies through integrating local or indigenous knowledge (IK) in Science lessons to make it accessible and relevant to learners. But, it does not explicitly state how Science teachers should go about enacting this. It is against this caveat that this study aimed at finding out indigenous practices and knowledge in the community and from two community members that could be integrated into the topic on waves and sound in Grade 10 Physical Sciences lessons with the view to establishing its influence (or not) on learners’ conceptions and dispositions towards Science. The study was conducted at Buyelembo Combined School (pseudonym), a township school in the Sarah Baartman District, in the Eastern Cape in South Africa. The research participants were 18 Grade 10 Physical Sciences learners, two Physical Sciences teachers and two community members. Data were generated using the learners’ group activity, discussions and presentations, observations (participatory observations and lesson observations), stimulated recall interviews and reflections. A thematic and inductive-deductive approach to data analysis was employed to come up with sub-themes and themes. Underpinned by an interpretivist perspective and informed by Vygotsky’s socio-cultural theory, a qualitative case study approach was adopted. Additionally, Ogunniyi’s Contiguity Argumentative Theory (CAT) was used as an analytical framework. The five cognitive states of CAT were employed to analyse data during the social interactions to surface any contradictions. The findings from this study revealed that there are indigenous practices and knowledge in relation to the sea that can be integrated into the topic on waves and sound in Grade 10 Physical Sciences lessons. However, regarding relevance of those indigenous practices and knowledge to science, the study revealed that the learners found no relevance at all but discussions and argumentation were enhanced. In addition, findings from this study revealed that the learners’ conceptions, dispositions, and sense-making in science were influenced positively through using hands-on practical activities when teaching Science concepts. Lastly, the study revealed that the use of mother tongue by the community members, learners and the teachers together with the language of learning and teaching promoted learner talk. Based on the findings of this study, I recommend that there is a need to support teachers on how to integrate indigenous practices and knowledge in their teaching, particularly when teaching Physical Sciences.
- Full Text:
- Date Issued: 2020
- Authors: Manyana, Xolani Justice
- Date: 2020
- Subjects: Physical sciences -- Study and teaching (Secondary) -- South Africa , Physical sciences -- Study and teaching (Secondary) -- South Africa -- Case studies , Ethnoscience -- Study and teaching -- South Africa , Schools -- South Africa -- Curricula , Social change
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/142889 , vital:38173
- Description: The lack of interest and hence the decline in the number of learners doing Science in schools, is attributed in part to the decontextualised ways in which Science is taught. As an attempt to address this challenge, the new South African National Curriculum Policy Statement (CAPS) encourages Science teachers to use culturally responsive pedagogies through integrating local or indigenous knowledge (IK) in Science lessons to make it accessible and relevant to learners. But, it does not explicitly state how Science teachers should go about enacting this. It is against this caveat that this study aimed at finding out indigenous practices and knowledge in the community and from two community members that could be integrated into the topic on waves and sound in Grade 10 Physical Sciences lessons with the view to establishing its influence (or not) on learners’ conceptions and dispositions towards Science. The study was conducted at Buyelembo Combined School (pseudonym), a township school in the Sarah Baartman District, in the Eastern Cape in South Africa. The research participants were 18 Grade 10 Physical Sciences learners, two Physical Sciences teachers and two community members. Data were generated using the learners’ group activity, discussions and presentations, observations (participatory observations and lesson observations), stimulated recall interviews and reflections. A thematic and inductive-deductive approach to data analysis was employed to come up with sub-themes and themes. Underpinned by an interpretivist perspective and informed by Vygotsky’s socio-cultural theory, a qualitative case study approach was adopted. Additionally, Ogunniyi’s Contiguity Argumentative Theory (CAT) was used as an analytical framework. The five cognitive states of CAT were employed to analyse data during the social interactions to surface any contradictions. The findings from this study revealed that there are indigenous practices and knowledge in relation to the sea that can be integrated into the topic on waves and sound in Grade 10 Physical Sciences lessons. However, regarding relevance of those indigenous practices and knowledge to science, the study revealed that the learners found no relevance at all but discussions and argumentation were enhanced. In addition, findings from this study revealed that the learners’ conceptions, dispositions, and sense-making in science were influenced positively through using hands-on practical activities when teaching Science concepts. Lastly, the study revealed that the use of mother tongue by the community members, learners and the teachers together with the language of learning and teaching promoted learner talk. Based on the findings of this study, I recommend that there is a need to support teachers on how to integrate indigenous practices and knowledge in their teaching, particularly when teaching Physical Sciences.
- Full Text:
- Date Issued: 2020
“Womxn like me are made”: politics and poetics in Claudia Rankine’s Citizen
- Authors: Wilken, Chelsey
- Date: 2020
- Subjects: Rankine, Claudia, 1963- Citizen , Putuma, Koleka -- Collective amnesia , Black people -- Race identity , Black people in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145735 , vital:38462
- Description: This thesis utilises an interdisciplinary approach to understand the political significance of the experimental poetics used by Claudia Rankine in Citizen: An American Lyric and Koleka Putuma in Collective Amnesia. Rankine and Putuma offer contemporary reflections on what it means to occupy marginalised spaces in society. These artists experiment with formal and conventional aspects of literature to explore and create new definitions of what it means to be Black in society. Their works and techniques allow for thinking outside of dominant ideologies of race and posit alternative Black identities that are not found within canonical theory on Blackness. This project reflects on existing theories of Black subjectivity as evident in Frantz Fanon’s Black Skin, White Masks and Aimé Césaire’s Notebook on the Return to My Native Land. While these theorists did not reject the role of Black women in Western civilisation, they should be read as a moment in a series of counter-discourse to the Black Other rather than the finite canon of Black subjectivity. The emergence of Rankine and Putuma’s experimental poetics works to disrupt the conflation of the Black subject with the Black heteronormative male. Using Michelle M. Wright’s Physics of Blackness as its primary theoretical framework, this project advocates alternative and disruptive readings of Blackness that potentially shift Blackness away from its conflation with nationalism, masculinity and heteronormativity. This thesis uses a dialogical approach between political theory and literature which allows for Citizen and Collective Amnesia to be read as acts of resistance to epistemological erasure and as articulations of the politics relevant to the poets’ lived experiences. Both the United States and South Africa have a history of institutionalised racial segregation, which allows Rankine and Putuma to be read in relation to one another. Where the Civil Rights movement and the anti-apartheid struggle were both foregrounded as male-lead liberation movements contemporary social movements including #blacklivesmatter and #feesmustfall have initiated a return to the androcentric philosophies of Malcom X and Steve Biko, for example. As such Rankine and Putuma’s literature and art marks a reclamation of female empowerment and visibility in the face of a political rhetoric that continues to be masculine and nationalist in nature. In the absence of a space where Black female and queer bodies are adequately recognised, the poetry they write creates a space of self-representation and recognition.
- Full Text:
- Date Issued: 2020
- Authors: Wilken, Chelsey
- Date: 2020
- Subjects: Rankine, Claudia, 1963- Citizen , Putuma, Koleka -- Collective amnesia , Black people -- Race identity , Black people in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145735 , vital:38462
- Description: This thesis utilises an interdisciplinary approach to understand the political significance of the experimental poetics used by Claudia Rankine in Citizen: An American Lyric and Koleka Putuma in Collective Amnesia. Rankine and Putuma offer contemporary reflections on what it means to occupy marginalised spaces in society. These artists experiment with formal and conventional aspects of literature to explore and create new definitions of what it means to be Black in society. Their works and techniques allow for thinking outside of dominant ideologies of race and posit alternative Black identities that are not found within canonical theory on Blackness. This project reflects on existing theories of Black subjectivity as evident in Frantz Fanon’s Black Skin, White Masks and Aimé Césaire’s Notebook on the Return to My Native Land. While these theorists did not reject the role of Black women in Western civilisation, they should be read as a moment in a series of counter-discourse to the Black Other rather than the finite canon of Black subjectivity. The emergence of Rankine and Putuma’s experimental poetics works to disrupt the conflation of the Black subject with the Black heteronormative male. Using Michelle M. Wright’s Physics of Blackness as its primary theoretical framework, this project advocates alternative and disruptive readings of Blackness that potentially shift Blackness away from its conflation with nationalism, masculinity and heteronormativity. This thesis uses a dialogical approach between political theory and literature which allows for Citizen and Collective Amnesia to be read as acts of resistance to epistemological erasure and as articulations of the politics relevant to the poets’ lived experiences. Both the United States and South Africa have a history of institutionalised racial segregation, which allows Rankine and Putuma to be read in relation to one another. Where the Civil Rights movement and the anti-apartheid struggle were both foregrounded as male-lead liberation movements contemporary social movements including #blacklivesmatter and #feesmustfall have initiated a return to the androcentric philosophies of Malcom X and Steve Biko, for example. As such Rankine and Putuma’s literature and art marks a reclamation of female empowerment and visibility in the face of a political rhetoric that continues to be masculine and nationalist in nature. In the absence of a space where Black female and queer bodies are adequately recognised, the poetry they write creates a space of self-representation and recognition.
- Full Text:
- Date Issued: 2020
Carnivore intra-guild competition in Selati Game Reserve, Limpopo Province, South Africa
- Authors: Comley, Jessica
- Date: 2020
- Subjects: Hyenas -- Behavior -- South Africa , Hyenas -- South Africa , Hyenas -- Ecology -- South Africa , Top predators -- South Africa , Top predators -- Ecology -- South Africa , Animal communities -- South Africa , Animal behavior -- South Africa , Mutualism (Biology) -- South Africa , Coexistence of species -- South Africa , Game farms -- South Africa , Selati Game Reserve (South Africa)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115558 , vital:34163
- Description: Carnivore intra-guild interactions can be important drivers of carnivore community composition and ecosystem functioning. Large carnivores are particularly important since they occupy the highest trophic levels and can exert extensive influences on subordinate carnivores and prey species. Given Africa’s rapidly expanding human population, enclosed reserves such as those found in South Africa, may become increasingly important for carnivore conservation. A major concern, however, is that the interactions and co-existence of multiple carnivores in these systems is poorly understood. Additionally, the majority of reserves in South Africa are small ( 400km²), potentially increasing the likelihood of competition. My research aimed to provide insight into the interactions and co-existence of a multi-carnivore community within a small, enclosed reserve in South Africa (Selati Game Reserve). I tackled this task by using a combination of field techniques including camera trap surveys, ungulate transect surveys, aerial count surveys, location data collected from collared large carnivores and scat and kill site analyses. I found that carnivore-carnivore interactions, and their associated impacts, varied within the carnivore guild and that co-existence may be due to trade-offs between various risks (i.e. interference and exploitative competition) and benefits (i.e. resources such as food and space). My findings also revealed that large carnivores, such as lions (Panthera leo), spotted hyaenas (Crocuta crocuta) and leopards (Panthera pardus) do not have homogenous effects and that site-specific research on multiple-carnivores is integral for conserving biodiversity and ecosystem dynamics. Lions were the dominant large carnivore (in terms of intra-guild predation, space use and resource use) despite being outnumbered seven to one by spotted hyaenas. Leopard occupancy was negatively influenced by lions and leopard diet overlapped almost completely (91%) with spotted hyaenas, suggesting increased kleptoparasitism of leopard kills by spotted hyaenas. While my study provides valuable insight into the complexity of carnivore intra-guild competition in a small, enclosed reserve it also highlights major research gaps and emphasises the need for ecosystem-based research throughout southern Africa to fully understand how multiple sympatric carnivores co-exist in these systems.
- Full Text:
- Date Issued: 2020
- Authors: Comley, Jessica
- Date: 2020
- Subjects: Hyenas -- Behavior -- South Africa , Hyenas -- South Africa , Hyenas -- Ecology -- South Africa , Top predators -- South Africa , Top predators -- Ecology -- South Africa , Animal communities -- South Africa , Animal behavior -- South Africa , Mutualism (Biology) -- South Africa , Coexistence of species -- South Africa , Game farms -- South Africa , Selati Game Reserve (South Africa)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115558 , vital:34163
- Description: Carnivore intra-guild interactions can be important drivers of carnivore community composition and ecosystem functioning. Large carnivores are particularly important since they occupy the highest trophic levels and can exert extensive influences on subordinate carnivores and prey species. Given Africa’s rapidly expanding human population, enclosed reserves such as those found in South Africa, may become increasingly important for carnivore conservation. A major concern, however, is that the interactions and co-existence of multiple carnivores in these systems is poorly understood. Additionally, the majority of reserves in South Africa are small ( 400km²), potentially increasing the likelihood of competition. My research aimed to provide insight into the interactions and co-existence of a multi-carnivore community within a small, enclosed reserve in South Africa (Selati Game Reserve). I tackled this task by using a combination of field techniques including camera trap surveys, ungulate transect surveys, aerial count surveys, location data collected from collared large carnivores and scat and kill site analyses. I found that carnivore-carnivore interactions, and their associated impacts, varied within the carnivore guild and that co-existence may be due to trade-offs between various risks (i.e. interference and exploitative competition) and benefits (i.e. resources such as food and space). My findings also revealed that large carnivores, such as lions (Panthera leo), spotted hyaenas (Crocuta crocuta) and leopards (Panthera pardus) do not have homogenous effects and that site-specific research on multiple-carnivores is integral for conserving biodiversity and ecosystem dynamics. Lions were the dominant large carnivore (in terms of intra-guild predation, space use and resource use) despite being outnumbered seven to one by spotted hyaenas. Leopard occupancy was negatively influenced by lions and leopard diet overlapped almost completely (91%) with spotted hyaenas, suggesting increased kleptoparasitism of leopard kills by spotted hyaenas. While my study provides valuable insight into the complexity of carnivore intra-guild competition in a small, enclosed reserve it also highlights major research gaps and emphasises the need for ecosystem-based research throughout southern Africa to fully understand how multiple sympatric carnivores co-exist in these systems.
- Full Text:
- Date Issued: 2020
A critical investigation of leadership in a Technical, Vocational Education and Training college in the Eastern Cape
- Authors: Chagi, Nonkonzo
- Date: 2020
- Subjects: Technical education -- South Africa , Vocational education -- South Africa , Educational leadership -- South Africa , Postsecondary education -- South Africa -- Administration
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/140045 , vital:37827
- Description: Far-reaching reforms of the TVET college system – including a merger and frequent revisioning of the colleges’ role in the educational landscape of South Africa – have focused renewed attention on this sector. The fact that the sector has been plagued by poor performance – even to the extent that several colleges have been placed under administration – suggests problems at the level of leadership. This study sought to explore key role-players’ understanding of the leadership and management challenges faced by a TVET college and, by examining responses to these challenges, develop a sense of what leadership means in the sector. The study drew on three leadership theories – distributed leadership, transactional leadership as depicted in political models of management, and critical leadership – to help make sense of the findings. A qualitative case study design was used to explore key respondents’ views and lived experiences. The respondents were the principal, two deputy principals, a council member, three campus managers and a programme head. Interviews, questionnaires and document analysis were the chief data collection tools. The study found that critical leadership was the dominant approach at the college. This was revealed in the college leadership’s awareness of broader societal needs and its own role in operating in a socially just manner. College leadership also revealed signs of rejecting the status quo and opposing state control and bureaucracy, in favour of reactionary initiatives. There was limited evidence of distributed and transactional leadership. In fact, ‘leadership’ as such, seemed not to be part of the college discourse, suggesting that the concept and habit of leadership was not broadly discussed, shared and promoted. This sense was strengthened by the fact that at the time of the study, the college was headed by a charismatic and visionary leader. Indeed, the problem at the college seemed to be the Department of Higher Education and Training, which has failed the college in a number of ways.
- Full Text:
- Date Issued: 2020
- Authors: Chagi, Nonkonzo
- Date: 2020
- Subjects: Technical education -- South Africa , Vocational education -- South Africa , Educational leadership -- South Africa , Postsecondary education -- South Africa -- Administration
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/140045 , vital:37827
- Description: Far-reaching reforms of the TVET college system – including a merger and frequent revisioning of the colleges’ role in the educational landscape of South Africa – have focused renewed attention on this sector. The fact that the sector has been plagued by poor performance – even to the extent that several colleges have been placed under administration – suggests problems at the level of leadership. This study sought to explore key role-players’ understanding of the leadership and management challenges faced by a TVET college and, by examining responses to these challenges, develop a sense of what leadership means in the sector. The study drew on three leadership theories – distributed leadership, transactional leadership as depicted in political models of management, and critical leadership – to help make sense of the findings. A qualitative case study design was used to explore key respondents’ views and lived experiences. The respondents were the principal, two deputy principals, a council member, three campus managers and a programme head. Interviews, questionnaires and document analysis were the chief data collection tools. The study found that critical leadership was the dominant approach at the college. This was revealed in the college leadership’s awareness of broader societal needs and its own role in operating in a socially just manner. College leadership also revealed signs of rejecting the status quo and opposing state control and bureaucracy, in favour of reactionary initiatives. There was limited evidence of distributed and transactional leadership. In fact, ‘leadership’ as such, seemed not to be part of the college discourse, suggesting that the concept and habit of leadership was not broadly discussed, shared and promoted. This sense was strengthened by the fact that at the time of the study, the college was headed by a charismatic and visionary leader. Indeed, the problem at the college seemed to be the Department of Higher Education and Training, which has failed the college in a number of ways.
- Full Text:
- Date Issued: 2020
The lived experiences of women with human immunodeficiency virus (HIV) in Malawi: an interpretative phenomenological analysis (IPA)
- Authors: Nkhalamba, Mathero Michelle
- Date: 2020
- Subjects: HIV-positive women -- Malawi , HIV infections -- Sex factors -- Malawi , HIV infections -- Social aspects -- Malawi , HIV-positive women -- Malawi -- Social conditions , HIV-positive women -- Malawi -- Economic conditions , Poverty -- Malawi , Antiretroviral agents -- Malawi , Phenomenological psychology
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145291 , vital:38425
- Description: Research on African women and HIV, particularly research that investigates their experiences of living with the virus, has been relatively peripheral. As a response to the apparent knowledge and research gaps, this project is a qualitative study involving women living with human immunodeficiency virus (WLHIV) and attending an anti-retroviral treatment (ART) clinic at Zomba Central Hospital in Southern Malawi. The study utilised an interpretative phenomenological analysis (IPA) approach, which informed all aspects of the data-collection and data-analysis processes. Using purposive sampling, 12 women were recruited and interviewed on three occasions over a period of six months. The interviews were conducted in Chichewa and audio recorded and later transcribed into English. Fourteen superordinate themes emerged from the analysis representing the women’s prominent life experiences, how they received their diagnosis, and how they contained the trauma of their diagnosis. The analysis also developed themes regarding how they coped with the challenges of living with the human immunodeficiency virus (HIV) and made sense of their experiences. The results showed that the women struggled with multiple challenges experienced through their various identities as WLHIV. The findings also pointed to interlocking disadvantages that put the women at risk of infection, and which were present from childhood. This has implications for more structural and multidisciplinary interventions for WLHIV.
- Full Text:
- Date Issued: 2020
- Authors: Nkhalamba, Mathero Michelle
- Date: 2020
- Subjects: HIV-positive women -- Malawi , HIV infections -- Sex factors -- Malawi , HIV infections -- Social aspects -- Malawi , HIV-positive women -- Malawi -- Social conditions , HIV-positive women -- Malawi -- Economic conditions , Poverty -- Malawi , Antiretroviral agents -- Malawi , Phenomenological psychology
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145291 , vital:38425
- Description: Research on African women and HIV, particularly research that investigates their experiences of living with the virus, has been relatively peripheral. As a response to the apparent knowledge and research gaps, this project is a qualitative study involving women living with human immunodeficiency virus (WLHIV) and attending an anti-retroviral treatment (ART) clinic at Zomba Central Hospital in Southern Malawi. The study utilised an interpretative phenomenological analysis (IPA) approach, which informed all aspects of the data-collection and data-analysis processes. Using purposive sampling, 12 women were recruited and interviewed on three occasions over a period of six months. The interviews were conducted in Chichewa and audio recorded and later transcribed into English. Fourteen superordinate themes emerged from the analysis representing the women’s prominent life experiences, how they received their diagnosis, and how they contained the trauma of their diagnosis. The analysis also developed themes regarding how they coped with the challenges of living with the human immunodeficiency virus (HIV) and made sense of their experiences. The results showed that the women struggled with multiple challenges experienced through their various identities as WLHIV. The findings also pointed to interlocking disadvantages that put the women at risk of infection, and which were present from childhood. This has implications for more structural and multidisciplinary interventions for WLHIV.
- Full Text:
- Date Issued: 2020
Petrography, metamorphism, deformation and P-T conditions in the western arm of the Lufilian Arc - Zambezi, north-western Zambia
- Authors: Chilekwa, Mwango
- Date: 2020
- Subjects: Petrogenesis -- Zambia -- Zambezi District , Metamorphism (Geology) -- Zambia -- Zambezi District , Petrology -- Zambia -- Zambezi District , Formations (Geology) -- Zambia -- Zambezi District , Rock deformation -- Zambia -- Zambezi District , Lufilian Arc , Neoproterozoic Katangan R.A.T. (Roches Argilo Talqueuse) Subgroup
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/161971 , vital:40699
- Description: The Zambezi area in north-western Zambia is underlain by Neoproterozoic Katanga Supergroup and older, Archean to Mesoproterozoic Basement Supergroup rocks. The area lies within the Domes Region, which is a structural domain of the Lufilian Arc. The stratigraphic succession within Zambezi area is dominated by the Grand Conglomerate Formation (GC) and Mwashia Group which are the most extensive units, and the less abundant Lower and Upper Roan Groups of the Katanga Supergroup. They wrap around the domal Basement Supergroup units. The mineral assemblage of the Mwashia and the GC schists commonly contains garnet, anthophyllite and biotite. GC rocks show remnants of primary structures such as clasts and sedimentary features. Anthophyllite, garnet and biotite are the dominant Mg-Fe rich metamorphic minerals. However, these are iron rich for each mineral phase and has been attributed to iron rich protoliths. The earliest recognised deformation episode (D1) formed NE-SW S1 foliations within GC which is consistent with the regional structural trend in the western Lufilian Arc. S1 was later affected by D2 that generated downward facing F2 folds and S2 foliations. The other associated feature to D2 is garnet that grew as the result of pro-grade metamorphism. The D3 deformation fabric is not developed and did not affect much of the structural geometry of the Zambezi area. The peak assemblages of the Basement Supergroup and the Katanga Supergroup formed at mid-amphibolite facies conditions of 590 °C and 630 °C at an average pressure of 4.0 kbar. The Basement Supergroup has undergone retrograde metamorphism to greenschist facies condition indicated by presence of chlorite and also determined by biotite-anorthite isopleth in THERIAK DOMINO. At the eastern part of Zambezi area, the Katanga Supergroup rocks were retrogressed in the upper greenschist facies at about ~470°C and ~4.0 kbar due to isobaric cooling.
- Full Text:
- Date Issued: 2020
- Authors: Chilekwa, Mwango
- Date: 2020
- Subjects: Petrogenesis -- Zambia -- Zambezi District , Metamorphism (Geology) -- Zambia -- Zambezi District , Petrology -- Zambia -- Zambezi District , Formations (Geology) -- Zambia -- Zambezi District , Rock deformation -- Zambia -- Zambezi District , Lufilian Arc , Neoproterozoic Katangan R.A.T. (Roches Argilo Talqueuse) Subgroup
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/161971 , vital:40699
- Description: The Zambezi area in north-western Zambia is underlain by Neoproterozoic Katanga Supergroup and older, Archean to Mesoproterozoic Basement Supergroup rocks. The area lies within the Domes Region, which is a structural domain of the Lufilian Arc. The stratigraphic succession within Zambezi area is dominated by the Grand Conglomerate Formation (GC) and Mwashia Group which are the most extensive units, and the less abundant Lower and Upper Roan Groups of the Katanga Supergroup. They wrap around the domal Basement Supergroup units. The mineral assemblage of the Mwashia and the GC schists commonly contains garnet, anthophyllite and biotite. GC rocks show remnants of primary structures such as clasts and sedimentary features. Anthophyllite, garnet and biotite are the dominant Mg-Fe rich metamorphic minerals. However, these are iron rich for each mineral phase and has been attributed to iron rich protoliths. The earliest recognised deformation episode (D1) formed NE-SW S1 foliations within GC which is consistent with the regional structural trend in the western Lufilian Arc. S1 was later affected by D2 that generated downward facing F2 folds and S2 foliations. The other associated feature to D2 is garnet that grew as the result of pro-grade metamorphism. The D3 deformation fabric is not developed and did not affect much of the structural geometry of the Zambezi area. The peak assemblages of the Basement Supergroup and the Katanga Supergroup formed at mid-amphibolite facies conditions of 590 °C and 630 °C at an average pressure of 4.0 kbar. The Basement Supergroup has undergone retrograde metamorphism to greenschist facies condition indicated by presence of chlorite and also determined by biotite-anorthite isopleth in THERIAK DOMINO. At the eastern part of Zambezi area, the Katanga Supergroup rocks were retrogressed in the upper greenschist facies at about ~470°C and ~4.0 kbar due to isobaric cooling.
- Full Text:
- Date Issued: 2020
Observations of diffuse radio emission in the Perseus Galaxy Cluster
- Authors: Mungwariri, Clemence
- Date: 2020
- Subjects: Galaxies -- Clusters , Radio sources (Astronomy) , Radio interferometers , Perseus Galaxy Cluster , Diffuse radio emission
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/143325 , vital:38233
- Description: In this thesis we analysed Westerbork observations of the Perseus Galaxy Cluster at 1380 MHz. Observations consist of two different pointings, covering a total of ∼ 0.5 square degrees, one including the known mini halo and the source 3C 84, the other centred on the source 3C 83.1 B. We obtained images with 83 μJy beam⁻¹ and 240 μJy beam⁻¹ noise rms for the two pointings respectively. We achieved a 60000 : 1 dynamic range in the image containing the bright 3C 84 source. We imaged the mini halo surrounding 3C 84 at high sensitivity, measuring its diameter to be ∼140 kpc and its power 4 x 10²⁴ W Hz⁻¹. Its morphology agrees quite well with that observed at 240 MHz (e.g. Gendron-Marsolais et al., 2017). We measured the flux density of 3C 84 to be 20.5 ± 0.4 Jy at the 2007 epoch, consistent with a factor of ∼2 increase since the 1960s.
- Full Text:
- Date Issued: 2020
- Authors: Mungwariri, Clemence
- Date: 2020
- Subjects: Galaxies -- Clusters , Radio sources (Astronomy) , Radio interferometers , Perseus Galaxy Cluster , Diffuse radio emission
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/143325 , vital:38233
- Description: In this thesis we analysed Westerbork observations of the Perseus Galaxy Cluster at 1380 MHz. Observations consist of two different pointings, covering a total of ∼ 0.5 square degrees, one including the known mini halo and the source 3C 84, the other centred on the source 3C 83.1 B. We obtained images with 83 μJy beam⁻¹ and 240 μJy beam⁻¹ noise rms for the two pointings respectively. We achieved a 60000 : 1 dynamic range in the image containing the bright 3C 84 source. We imaged the mini halo surrounding 3C 84 at high sensitivity, measuring its diameter to be ∼140 kpc and its power 4 x 10²⁴ W Hz⁻¹. Its morphology agrees quite well with that observed at 240 MHz (e.g. Gendron-Marsolais et al., 2017). We measured the flux density of 3C 84 to be 20.5 ± 0.4 Jy at the 2007 epoch, consistent with a factor of ∼2 increase since the 1960s.
- Full Text:
- Date Issued: 2020
Development of graphene materials and phthalocyanines for application in dye-sensitized solar cells
- Authors: Chindeka, Francis
- Date: 2020
- Subjects: Dye-sensitized solar cells , Graphene , Phthalocyanines , Molecular orbitals , Impedance spectroscopy
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/166092 , vital:41328
- Description: Two sets of dye-sensitized solar cells (DSSCs) were fabricated. In the first set, dye-sensitized solar cells (DSSC) were fabricated by incorporating graphene materials as catalysts at the counter electrode. Platinum was also used as a catalyst for comparative purposes. Different phthalocyanines: hydroxyl indium tetracarboxyphenoxy phthalocyanine (1), chloro indium octacarboxy phthalocyanine (2) and dibenzoic acid silicon phthalocyanine (3) were used as dyes. Complex 3 gave the highest power conversion efficiency (η) of 3.19% when using nitrogen doped reduced graphene oxide nanosheets (NrGONS) as a catalyst at the counter electrode, and TiO2 containing rGONS at the anode. The value obtained is close to 3.8% obtained when using Pt catalyst instead of NrGONS at the cathode, thus confirming that NrGONS is a promising candidate to replace the more expensive Pt. The study also shows that placing rGONS on both the anode and cathode improves efficiency. In the second set, DSSCs were fabricated by using 2(3,5-biscarboxyphenoxy), 9(10), 16(17), 23(24)-tri(tertbutyl) phthalocyaninato Cu (4) and Zn (5) complexes as dyes on the ITO-TiO2 photoanodes containing reduced graphene oxide nanosheets (rGONS) or nitrogen-doped rGONS (NrGONS). The evaluation of the assembled DSSCs revealed that using ITO-TiO2-NrGONS-CuPc (4) photoanode had the highest fill factor (FF) and power conversion efficiency (ɳ) of 69 % and 4.36 % respectively. These results show that the asymmetrical phthalocyanine complexes (4) and (5) showed significant improvement on the performance of the DSSC compared to previous work on symmetrical carboxylated phthalocyanines with ɳ = 3.19%.
- Full Text:
- Date Issued: 2020
- Authors: Chindeka, Francis
- Date: 2020
- Subjects: Dye-sensitized solar cells , Graphene , Phthalocyanines , Molecular orbitals , Impedance spectroscopy
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/166092 , vital:41328
- Description: Two sets of dye-sensitized solar cells (DSSCs) were fabricated. In the first set, dye-sensitized solar cells (DSSC) were fabricated by incorporating graphene materials as catalysts at the counter electrode. Platinum was also used as a catalyst for comparative purposes. Different phthalocyanines: hydroxyl indium tetracarboxyphenoxy phthalocyanine (1), chloro indium octacarboxy phthalocyanine (2) and dibenzoic acid silicon phthalocyanine (3) were used as dyes. Complex 3 gave the highest power conversion efficiency (η) of 3.19% when using nitrogen doped reduced graphene oxide nanosheets (NrGONS) as a catalyst at the counter electrode, and TiO2 containing rGONS at the anode. The value obtained is close to 3.8% obtained when using Pt catalyst instead of NrGONS at the cathode, thus confirming that NrGONS is a promising candidate to replace the more expensive Pt. The study also shows that placing rGONS on both the anode and cathode improves efficiency. In the second set, DSSCs were fabricated by using 2(3,5-biscarboxyphenoxy), 9(10), 16(17), 23(24)-tri(tertbutyl) phthalocyaninato Cu (4) and Zn (5) complexes as dyes on the ITO-TiO2 photoanodes containing reduced graphene oxide nanosheets (rGONS) or nitrogen-doped rGONS (NrGONS). The evaluation of the assembled DSSCs revealed that using ITO-TiO2-NrGONS-CuPc (4) photoanode had the highest fill factor (FF) and power conversion efficiency (ɳ) of 69 % and 4.36 % respectively. These results show that the asymmetrical phthalocyanine complexes (4) and (5) showed significant improvement on the performance of the DSSC compared to previous work on symmetrical carboxylated phthalocyanines with ɳ = 3.19%.
- Full Text:
- Date Issued: 2020
Formulation development, manufacture and evaluation of a lamivudine-zidovudine nano co-crystal thermo-responsive suspension
- Authors: Witika, Bwalya Angel
- Date: 2020
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/140546 , vital:37897 , http://dx.doi.org/10.21504/10962/140546
- Description: Expected release date-April 2021
- Full Text:
- Date Issued: 2020
- Authors: Witika, Bwalya Angel
- Date: 2020
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/140546 , vital:37897 , http://dx.doi.org/10.21504/10962/140546
- Description: Expected release date-April 2021
- Full Text:
- Date Issued: 2020
A gendered analysis of conditional cash based transfers: a case study of Puntland Technical Vocational Skills Training Programme, Somalia
- Authors: Chitombi, Rumbidzai
- Date: 2020
- Subjects: Puntland Technical Vocational Skills Training Programme , Transfer payments -- Somalia -- Case studies , Economic assistance, Domestic -- Somalia , Economic development -- Social aspects -- Somalia , Women -- Somalia -- Social conditions
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167335 , vital:41469
- Description: As part of the worldwide development system, conditional cash transfer (CCT) programmes have become an increasingly popular policy and development approach in seeking to address poverty, especially in developing countries. Under the CCT programmes, beneficiaries are given assistance in the form of either cash or cash vouchers after fulfilling certain obligations of the development programme, such as attending training, enacting proper health care, or ensuring regular school attendance of children. The programmes have been described as a ‘double-edged sword’ since they aim to address poverty and, at the same time, reduce reliance on government largesse. In this regard, they are seen as potentially effective, and more empowering, alternatives to more traditional social assistance programmes whereby poor people receive welfare assistance in the form of ‘in kind’ and ‘unconditional’ assistance, receiving this as either food or shelter commodities, and without having to meet any conditions in doing so. This ‘traditional’ way of assisting poor people has largely been criticised for creating a dependency syndrome amongst the beneficiaries. In certain cases, CCT programmes focus specifically on women, either in receiving the cash transfer or in meeting the conditions attached to the programme, or both. In this context, considerable debate exists in the scholarly literature about the effects of such CCT programmes on the situation and status of women, specifically in terms of possibly empowering women. While some scholars claim that these programmes enhance the human and financial assets of women, others argue that focusing specifically on women, and as care-givers within households, tends to reproduce gender-based inequalities and subordination. Since gender equality and female empowerment are now key issues in global development spheres, and at national levels, this thesis aims to contribute to literature on the effects of CCTs on gender and women’s empowerment. This is pursued by way of a gendered perspective on CCTs as a development methodology for empowering women with reference to Somalia, using the Puntland Technical Vocational Skills Training programme as a case study. This programme focused, in the main, on internally-displaced people in Somalia, with a particular emphasis on women in meeting the programme conditions (i.e. participating in a training programme) and in being the cash recipients. The study used both quantitative and qualitative approaches for data collection and analysis, focusing on sixty selected beneficiaries who participated in the Puntland Technical Vocational skills training programme in Somalia from 2013. The thesis examines the prevailing structures (including cultural dynamics and socio-economic factors) in Somalia which lead to women’s subordination, notably in the light of significant internal displacement because of war and conflict and the emergence of internally-displaced camps. On this basis, from a gendered perspective, there is a critical appraisal of the manner in which the Puntland CCT programme affected women’s subordinate status, including how it may have led to the restructuring of gendered relations at both household and community levels. In offering this appraisal with reference to the Puntland programme, the thesis argues that women’s subordination and, by extension, women’s empowerment, is multi-faceted, and that continuity and change along the dimensions of subordination is often uneven and contradictory. Further, as also demonstrated in the Puntland case study, women’s subordination (as a social totality) is not a totalising system, such that women regularly make use of gaps in the system as opportunities to enhance their well-being without confronting the totality of the system.
- Full Text:
- Date Issued: 2020
- Authors: Chitombi, Rumbidzai
- Date: 2020
- Subjects: Puntland Technical Vocational Skills Training Programme , Transfer payments -- Somalia -- Case studies , Economic assistance, Domestic -- Somalia , Economic development -- Social aspects -- Somalia , Women -- Somalia -- Social conditions
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167335 , vital:41469
- Description: As part of the worldwide development system, conditional cash transfer (CCT) programmes have become an increasingly popular policy and development approach in seeking to address poverty, especially in developing countries. Under the CCT programmes, beneficiaries are given assistance in the form of either cash or cash vouchers after fulfilling certain obligations of the development programme, such as attending training, enacting proper health care, or ensuring regular school attendance of children. The programmes have been described as a ‘double-edged sword’ since they aim to address poverty and, at the same time, reduce reliance on government largesse. In this regard, they are seen as potentially effective, and more empowering, alternatives to more traditional social assistance programmes whereby poor people receive welfare assistance in the form of ‘in kind’ and ‘unconditional’ assistance, receiving this as either food or shelter commodities, and without having to meet any conditions in doing so. This ‘traditional’ way of assisting poor people has largely been criticised for creating a dependency syndrome amongst the beneficiaries. In certain cases, CCT programmes focus specifically on women, either in receiving the cash transfer or in meeting the conditions attached to the programme, or both. In this context, considerable debate exists in the scholarly literature about the effects of such CCT programmes on the situation and status of women, specifically in terms of possibly empowering women. While some scholars claim that these programmes enhance the human and financial assets of women, others argue that focusing specifically on women, and as care-givers within households, tends to reproduce gender-based inequalities and subordination. Since gender equality and female empowerment are now key issues in global development spheres, and at national levels, this thesis aims to contribute to literature on the effects of CCTs on gender and women’s empowerment. This is pursued by way of a gendered perspective on CCTs as a development methodology for empowering women with reference to Somalia, using the Puntland Technical Vocational Skills Training programme as a case study. This programme focused, in the main, on internally-displaced people in Somalia, with a particular emphasis on women in meeting the programme conditions (i.e. participating in a training programme) and in being the cash recipients. The study used both quantitative and qualitative approaches for data collection and analysis, focusing on sixty selected beneficiaries who participated in the Puntland Technical Vocational skills training programme in Somalia from 2013. The thesis examines the prevailing structures (including cultural dynamics and socio-economic factors) in Somalia which lead to women’s subordination, notably in the light of significant internal displacement because of war and conflict and the emergence of internally-displaced camps. On this basis, from a gendered perspective, there is a critical appraisal of the manner in which the Puntland CCT programme affected women’s subordinate status, including how it may have led to the restructuring of gendered relations at both household and community levels. In offering this appraisal with reference to the Puntland programme, the thesis argues that women’s subordination and, by extension, women’s empowerment, is multi-faceted, and that continuity and change along the dimensions of subordination is often uneven and contradictory. Further, as also demonstrated in the Puntland case study, women’s subordination (as a social totality) is not a totalising system, such that women regularly make use of gaps in the system as opportunities to enhance their well-being without confronting the totality of the system.
- Full Text:
- Date Issued: 2020
Repurposing a polymer precursor scaffold for medicinal application: Synthesis, characterization and biological evaluation of ferrocenyl 1,3-benzoxazine derivatives as potential antiprotozoal and anticancer agents
- Authors: Mbaba, Mziyanda
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/164502 , vital:41124 , DOI 10.21504/10962/164502
- Description: The benzoxazines are a prominent class of heterocyclic compounds that possess a multitude of properties. To this end, benzoxazine derivatives have been used as versatile compounds for various utilities ranging from biological applications to the fabrication of polymers. Particularly, the 1,3-benzoxazine scaffold has featured in several bioactive compounds showing antimalarial, anticancer and antibacterial activities. Traditionally, it has been employed as a substrate in the synthesis of polymers with appealing physical and chemical properties. Due to the increasing interest in the polymer application of 1,3-benzoxazines, research of the 1,3-benzoxazine motif for polymer synthesis has been prioritized over other applications including its medicinal potential. The continuous development of resistance to clinical anticancer and antimalarial drugs has necessitated the need for the search of innovative bioactive compounds as potential alternative medicinal agents. To address this, the field of medicinal chemistry is adapting new approaches to counter resistance by incorporating nonconventional chemical moieties such as organometallic complexes, like ferrocene, into bioactive chemical motifs to serve as novel compounds with medicinal benefits. Incorporation of ferrocene into known bioactive chemical moieties has been shown to impart beneficial biological effects into the resultant compounds, which include the introduction of novel, and sometimes varied, mechanistic modalities and enhanced potency. Presented with the benefits of this strategy, the current work aims to design and evaluate the pharmaceutical capacity of novel derivatives containing 1,3-benzoxazine scaffold (traditionally applied in polymer synthesis) hybridized with the organometallic ferrocene unit as bioactive agents. Using a combination of expedient synthetic procedures such as the Burke three-component Mannich-type condensation, Vilsmeier-Haack formylation and reductive amination, four series of ferrocenyl 1,3-benzoxazine derivatives were synthesized and their structures confirmed by common spectroscopic techniques: nuclear magnetic resonance (NMR), infrared spectroscopy (IR) and high-resolution mass spectrometry (HRMS). The target compounds were evaluated in vitro for potential antimalarial and anticancer activities against strains of the malaria parasite (Plasmodium falciparum 3D7 and Dd2) and the triple-negative breast cancer cell line HCC70. Compounds exhibited higher potency towards the Plasmodium falciparum strains with IC50 values in the low and sub-micromolar range in comparison to the breast cancer cell line against for which mid-molar activities were observed. To gain insight into the possible mode of action of ferrocenyl 1,3-benzoxazines, representative compounds showing most efficacy from each series were assessed for DNA binding affinity by employing UV-Vis and fluorescence DNA titration experiments. The selected compounds were found to interact with the DNA by binding to the minor groove, and these findings were confirmed by in silico ligand docking studies using a B-DNA structure as the receptor. Compound 3.16c (IC50: 0.261 μM [3D7], 0.599 μM [Dd2], 11.0 μM [HCC70]), which emerged as the most promising compound, was found to induce DNA damage in HCC70 cancer cells when investigated for effects of DNA interaction. Additionally, compound 3.16c displayed a higher binding constant (Kb) against DNA isolated from 3D7 Plasmodium falciparum trophozoites (Kb = 1.88×106 M-1) than the mammalian DNA (Kb = 6.33×104 M-1) from calf thymus, thus explaining the preferred selectivity of the compounds for the malaria parasite. Moreover, the investigated compounds demonstrated binding affinity for synthetic hemozoin, β-hematin. Collectively, these data suggest that the compounds possess a dual mode of action for antimalarial activity involving DNA interaction and hemozoin inhibition. , Thesis (PhD) -- Faculty of Science, Chemistry, 2020
- Full Text:
- Date Issued: 2020
- Authors: Mbaba, Mziyanda
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/164502 , vital:41124 , DOI 10.21504/10962/164502
- Description: The benzoxazines are a prominent class of heterocyclic compounds that possess a multitude of properties. To this end, benzoxazine derivatives have been used as versatile compounds for various utilities ranging from biological applications to the fabrication of polymers. Particularly, the 1,3-benzoxazine scaffold has featured in several bioactive compounds showing antimalarial, anticancer and antibacterial activities. Traditionally, it has been employed as a substrate in the synthesis of polymers with appealing physical and chemical properties. Due to the increasing interest in the polymer application of 1,3-benzoxazines, research of the 1,3-benzoxazine motif for polymer synthesis has been prioritized over other applications including its medicinal potential. The continuous development of resistance to clinical anticancer and antimalarial drugs has necessitated the need for the search of innovative bioactive compounds as potential alternative medicinal agents. To address this, the field of medicinal chemistry is adapting new approaches to counter resistance by incorporating nonconventional chemical moieties such as organometallic complexes, like ferrocene, into bioactive chemical motifs to serve as novel compounds with medicinal benefits. Incorporation of ferrocene into known bioactive chemical moieties has been shown to impart beneficial biological effects into the resultant compounds, which include the introduction of novel, and sometimes varied, mechanistic modalities and enhanced potency. Presented with the benefits of this strategy, the current work aims to design and evaluate the pharmaceutical capacity of novel derivatives containing 1,3-benzoxazine scaffold (traditionally applied in polymer synthesis) hybridized with the organometallic ferrocene unit as bioactive agents. Using a combination of expedient synthetic procedures such as the Burke three-component Mannich-type condensation, Vilsmeier-Haack formylation and reductive amination, four series of ferrocenyl 1,3-benzoxazine derivatives were synthesized and their structures confirmed by common spectroscopic techniques: nuclear magnetic resonance (NMR), infrared spectroscopy (IR) and high-resolution mass spectrometry (HRMS). The target compounds were evaluated in vitro for potential antimalarial and anticancer activities against strains of the malaria parasite (Plasmodium falciparum 3D7 and Dd2) and the triple-negative breast cancer cell line HCC70. Compounds exhibited higher potency towards the Plasmodium falciparum strains with IC50 values in the low and sub-micromolar range in comparison to the breast cancer cell line against for which mid-molar activities were observed. To gain insight into the possible mode of action of ferrocenyl 1,3-benzoxazines, representative compounds showing most efficacy from each series were assessed for DNA binding affinity by employing UV-Vis and fluorescence DNA titration experiments. The selected compounds were found to interact with the DNA by binding to the minor groove, and these findings were confirmed by in silico ligand docking studies using a B-DNA structure as the receptor. Compound 3.16c (IC50: 0.261 μM [3D7], 0.599 μM [Dd2], 11.0 μM [HCC70]), which emerged as the most promising compound, was found to induce DNA damage in HCC70 cancer cells when investigated for effects of DNA interaction. Additionally, compound 3.16c displayed a higher binding constant (Kb) against DNA isolated from 3D7 Plasmodium falciparum trophozoites (Kb = 1.88×106 M-1) than the mammalian DNA (Kb = 6.33×104 M-1) from calf thymus, thus explaining the preferred selectivity of the compounds for the malaria parasite. Moreover, the investigated compounds demonstrated binding affinity for synthetic hemozoin, β-hematin. Collectively, these data suggest that the compounds possess a dual mode of action for antimalarial activity involving DNA interaction and hemozoin inhibition. , Thesis (PhD) -- Faculty of Science, Chemistry, 2020
- Full Text:
- Date Issued: 2020
“Workers’ strikes and collective bargaining: a study of the SAMWU municipal worker strike of 2018, Port Elizabeth, South Africa”
- Authors: Gumbo, Eugene
- Date: 2020
- Subjects: South African Municipal Workers Union , Strikes and lockouts -- Municipal government -- South Africa -- Port Elizabeth , Collective bargaining -- Municipal employees -- South Africa -- Port Elizabeth , Philosophy, Marxist , Labor unions -- South Africa , Labor unions -- Law and legislation -- South Africa , Industrial relations -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/146916 , vital:38576
- Description: The focus of this study centered on investigating the perceptions and opinions surrounding the eruption of strike action and its effectiveness during a collective bargaining process. The case study employed was the 2018 municipal strike in Port Elizabeth, organised by the South African Municipal Workers Union (SAMWU). A Marxist theoretical framework was chosen for this study. It argues that strike action is a means through which workers communicate their dissatisfaction or enforce particular demands, with trade unions playing a protagonist’s role. Strike action, generally, is caused by a plethora of reasons ranging from disciplinary issues and conditions and hours of work, to be mention a few. However, the major force behind strike eruption is the wage agenda, as workers are always striving to get better wages while employers, on the other hand, attempt to reduce them so as to increase profits. South Africa has had its fair share of municipal strike action ever since the apartheid period, the early stages of democracy up to the contemporary times of the 21st century with various strategies, successes and losses being experienced. Democracy in South Africa also saw some developments in the labour sphere in relation to statutes surrounding strike action. The LRA and the Constitution of South Africa inform the right to strike and offer guidelines as well as consequences that steer strike action in a direction that does not jeopardize the workers, employers and the general public. The research found that workers do understand what strike action is, its causes and its various implications. Furthermore, it was discovered that this worker tool has been successful in putting pressure on the negotiation process as well as luring employers back to the negotiation table, for example. However, it was also uncovered that there are present, factors that hampered the impact of strike action during the bargaining procedure in focus. These are namely, the political institutionalization of trade unions, ill-equipped union leaders, a reluctance to implement strike agreements by employers, the use of violence by municipal workers during the strike, to mention but a few. Therefore, when looking at the strike in question, the effectiveness of strike action during the collective bargaining process was found to be easily contestable.
- Full Text:
- Date Issued: 2020
- Authors: Gumbo, Eugene
- Date: 2020
- Subjects: South African Municipal Workers Union , Strikes and lockouts -- Municipal government -- South Africa -- Port Elizabeth , Collective bargaining -- Municipal employees -- South Africa -- Port Elizabeth , Philosophy, Marxist , Labor unions -- South Africa , Labor unions -- Law and legislation -- South Africa , Industrial relations -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/146916 , vital:38576
- Description: The focus of this study centered on investigating the perceptions and opinions surrounding the eruption of strike action and its effectiveness during a collective bargaining process. The case study employed was the 2018 municipal strike in Port Elizabeth, organised by the South African Municipal Workers Union (SAMWU). A Marxist theoretical framework was chosen for this study. It argues that strike action is a means through which workers communicate their dissatisfaction or enforce particular demands, with trade unions playing a protagonist’s role. Strike action, generally, is caused by a plethora of reasons ranging from disciplinary issues and conditions and hours of work, to be mention a few. However, the major force behind strike eruption is the wage agenda, as workers are always striving to get better wages while employers, on the other hand, attempt to reduce them so as to increase profits. South Africa has had its fair share of municipal strike action ever since the apartheid period, the early stages of democracy up to the contemporary times of the 21st century with various strategies, successes and losses being experienced. Democracy in South Africa also saw some developments in the labour sphere in relation to statutes surrounding strike action. The LRA and the Constitution of South Africa inform the right to strike and offer guidelines as well as consequences that steer strike action in a direction that does not jeopardize the workers, employers and the general public. The research found that workers do understand what strike action is, its causes and its various implications. Furthermore, it was discovered that this worker tool has been successful in putting pressure on the negotiation process as well as luring employers back to the negotiation table, for example. However, it was also uncovered that there are present, factors that hampered the impact of strike action during the bargaining procedure in focus. These are namely, the political institutionalization of trade unions, ill-equipped union leaders, a reluctance to implement strike agreements by employers, the use of violence by municipal workers during the strike, to mention but a few. Therefore, when looking at the strike in question, the effectiveness of strike action during the collective bargaining process was found to be easily contestable.
- Full Text:
- Date Issued: 2020
Evaluation of an NADPH-dependent assay for inhibition screening of Salmonella enterica DOXP Reguctoisomerase for identification of novel drug hit compounds
- Authors: Ngcongco, Khanyisile
- Date: 2020
- Subjects: 1-Deoxy-D-xylulose 5-phosphate , Antibiotics , Drug development , Salmonella , Enterobacteriaceae , Vaccines , Plasmodium falciparum , Mycobacterium tuberculosis
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167132 , vital:41440
- Description: Invasive non-typhoidal Salmonella, caused by the intracellular pathogen Salmonella enterica, has emerged as a major cause of bloodstream infections. It remains a neglected infection responsible for many deaths in Africa, as it fails to receive the level of support that is given to most better known infections. There are currently no vaccines against invasive non-typhoidal Salmonella. First-line antibiotics have been used for treatment, however, the rise in the resistance of the bacteria against these antibiotics has made treatment of invasive salmonellosis into a clinical problem. Therefore, the discovery of new compounds for the development of antibiotic drugs is required. Central metabolic pathways can be a useful source for identifying drug targets and among these is the non-mevalonate pathway, one of the pathways used for the biosynthesis of isoprenoid precursors. The second step of the non-mevalonate pathway involves the NADPH-dependent reduction of 1-deoxy-D-xylulose 5-phosphate (DOXP) into 2-C-methyl-D-erythritol 4-phosphate (MEP). 1-Deoxy-D-xylulose 5-phosphate (DOXP) reductoisomerase plays a vital role in the catalysis of this reaction and requires NADPH and divalent metal cations as co-factors for its activity. In this investigation recombinant DOXP reductoisomerase from Salmonella enterica, Plasmodium falciparum and Mycobacterium tuberculosis were biochemically characterized as potential targets for developing drugs that could be used as treatment of the disease. The expression and nickel-chelate affinity purification of S. enterica DOXP reductoisomerase in a fully functional native state was successfully achieved. However, the expression and purification of P. falciparum DXR and M. tuberculosis DXR was unsuccessful due to the formation of insoluble inclusion bodies. Although alternative purification strategies were explored, including dialysis and slow dilution, these proteins remained insoluble, making their functional analysis not possible. An NADPH-dependent enzyme assay was used to determine the activity of S. enterica DXR. This assay monitors the reduction of DOXP to MEP by measuring the absorbance at 340 nm, which reflects the concentration of NADPH. An alternative assay, resazurin reduction, which monitors the NADPH-dependent reduction of resazurin to resorufin, was explored for detecting enzyme activity. The recombinant S. enterica DOXP reductoisomerase had a specific activity of 0.126 ± 0.0014 μmol/min/mg protein and a Km and Vmax of 881 μM and 0.249 μmol/min/mg respectively. FR900098, a derivative of fosmidomycin, is a well-known inhibitor of DXR, however, the sensitivity of S. enterica DXR towards FR900098 has not yet been reported. The NADPH dependent enzyme and resazurin reduction assays were used to determine whether FR900098 has enzyme inhibitory effects against S. enterica DXR. Upon confirming that FR900098 is able to inhibit S. enterica DXR, FR900098 was used as a control compound in the screening of novel compounds. The S. enterica DXR enzyme was screened for inhibition by the collection of compounds from the Pathogen Box. Compounds that exhibited the desired inhibitory activity, referred to as ‘hits’ were selected for further investigation. These hits were confirmed using the NADPH-dependent enzyme assay, resulting in the identification of two different DXR inhibitor compounds, MMV002816, also known as diethylcarbamazine, and MMV228911. The inhibitory concentration (IC50) values of FR900098, MMV002816 and MMV228911 against S. enterica DXR were 1.038 μM, 2.173 μM and 6.861 μM respectively. The binding mode of these compounds to S. enterica DXR could lead to the discovery of novel druggable sites on the enzyme and stimulate the development of new antibiotics that can be used for treating Salmonella infections.
- Full Text:
- Date Issued: 2020
- Authors: Ngcongco, Khanyisile
- Date: 2020
- Subjects: 1-Deoxy-D-xylulose 5-phosphate , Antibiotics , Drug development , Salmonella , Enterobacteriaceae , Vaccines , Plasmodium falciparum , Mycobacterium tuberculosis
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167132 , vital:41440
- Description: Invasive non-typhoidal Salmonella, caused by the intracellular pathogen Salmonella enterica, has emerged as a major cause of bloodstream infections. It remains a neglected infection responsible for many deaths in Africa, as it fails to receive the level of support that is given to most better known infections. There are currently no vaccines against invasive non-typhoidal Salmonella. First-line antibiotics have been used for treatment, however, the rise in the resistance of the bacteria against these antibiotics has made treatment of invasive salmonellosis into a clinical problem. Therefore, the discovery of new compounds for the development of antibiotic drugs is required. Central metabolic pathways can be a useful source for identifying drug targets and among these is the non-mevalonate pathway, one of the pathways used for the biosynthesis of isoprenoid precursors. The second step of the non-mevalonate pathway involves the NADPH-dependent reduction of 1-deoxy-D-xylulose 5-phosphate (DOXP) into 2-C-methyl-D-erythritol 4-phosphate (MEP). 1-Deoxy-D-xylulose 5-phosphate (DOXP) reductoisomerase plays a vital role in the catalysis of this reaction and requires NADPH and divalent metal cations as co-factors for its activity. In this investigation recombinant DOXP reductoisomerase from Salmonella enterica, Plasmodium falciparum and Mycobacterium tuberculosis were biochemically characterized as potential targets for developing drugs that could be used as treatment of the disease. The expression and nickel-chelate affinity purification of S. enterica DOXP reductoisomerase in a fully functional native state was successfully achieved. However, the expression and purification of P. falciparum DXR and M. tuberculosis DXR was unsuccessful due to the formation of insoluble inclusion bodies. Although alternative purification strategies were explored, including dialysis and slow dilution, these proteins remained insoluble, making their functional analysis not possible. An NADPH-dependent enzyme assay was used to determine the activity of S. enterica DXR. This assay monitors the reduction of DOXP to MEP by measuring the absorbance at 340 nm, which reflects the concentration of NADPH. An alternative assay, resazurin reduction, which monitors the NADPH-dependent reduction of resazurin to resorufin, was explored for detecting enzyme activity. The recombinant S. enterica DOXP reductoisomerase had a specific activity of 0.126 ± 0.0014 μmol/min/mg protein and a Km and Vmax of 881 μM and 0.249 μmol/min/mg respectively. FR900098, a derivative of fosmidomycin, is a well-known inhibitor of DXR, however, the sensitivity of S. enterica DXR towards FR900098 has not yet been reported. The NADPH dependent enzyme and resazurin reduction assays were used to determine whether FR900098 has enzyme inhibitory effects against S. enterica DXR. Upon confirming that FR900098 is able to inhibit S. enterica DXR, FR900098 was used as a control compound in the screening of novel compounds. The S. enterica DXR enzyme was screened for inhibition by the collection of compounds from the Pathogen Box. Compounds that exhibited the desired inhibitory activity, referred to as ‘hits’ were selected for further investigation. These hits were confirmed using the NADPH-dependent enzyme assay, resulting in the identification of two different DXR inhibitor compounds, MMV002816, also known as diethylcarbamazine, and MMV228911. The inhibitory concentration (IC50) values of FR900098, MMV002816 and MMV228911 against S. enterica DXR were 1.038 μM, 2.173 μM and 6.861 μM respectively. The binding mode of these compounds to S. enterica DXR could lead to the discovery of novel druggable sites on the enzyme and stimulate the development of new antibiotics that can be used for treating Salmonella infections.
- Full Text:
- Date Issued: 2020
Creative production and existential thought: a feminist existential analysis of South African visual artist Berni Searle’s artwork
- Authors: Mokwena, Palesa
- Date: 2020
- Subjects: Women artists -- South Africa , Women artists, Black -- South Africa , Existentialism and art , Feminism and art -- South Africa , Searle, Berni
- Language: English
- Type: text , Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/148005 , vital:38701
- Description: Through an analysis of the work of South African artist Berni Searle, my study will investigate feminist existential ideas and concepts that have been explored by various creative producers in and outside of Europe/South Africa through different forms of creative productions and under different epistemological categories. ‘Canons’ of European existentialist/feminist thought often exclude the existence of feminist existential knowledge productions and producers outside of Europe. In conducting this study, I am responding to the past and present separatist and identitarian categorisations of creative productions from black/African creative producers, particularly women creative producers in South Africa, creating an alternative canonisation around their selected works. Although canons have been and can be used to drive separatist and identitarian categorisations, it is my hope to elucidate a discourse around the preservations and acknowledgements of South African creative and knowledge productions through a feminist existential framework that canonises important black feminist existentialist works and thereby brings to light their intellectual contributions over and above their identities. My development of a South African feminist existentialism is an attempt to graft a more intersectional, holistic framework to introduce in the feminist and existential discourses, and to proffer a new intersectional holistic paradigm of discussing categories that do not limit creative productions. To frame this research, I will reflect on the politics of historical and contemporary South African society as it is reflected in the works of the chosen creative producers and theorists and to question how we respond as creative feminist existentialists to contemporary South African struggles and how such a lens can be activated as a creative-theoretical tool of investigation.
- Full Text:
- Date Issued: 2020
- Authors: Mokwena, Palesa
- Date: 2020
- Subjects: Women artists -- South Africa , Women artists, Black -- South Africa , Existentialism and art , Feminism and art -- South Africa , Searle, Berni
- Language: English
- Type: text , Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/148005 , vital:38701
- Description: Through an analysis of the work of South African artist Berni Searle, my study will investigate feminist existential ideas and concepts that have been explored by various creative producers in and outside of Europe/South Africa through different forms of creative productions and under different epistemological categories. ‘Canons’ of European existentialist/feminist thought often exclude the existence of feminist existential knowledge productions and producers outside of Europe. In conducting this study, I am responding to the past and present separatist and identitarian categorisations of creative productions from black/African creative producers, particularly women creative producers in South Africa, creating an alternative canonisation around their selected works. Although canons have been and can be used to drive separatist and identitarian categorisations, it is my hope to elucidate a discourse around the preservations and acknowledgements of South African creative and knowledge productions through a feminist existential framework that canonises important black feminist existentialist works and thereby brings to light their intellectual contributions over and above their identities. My development of a South African feminist existentialism is an attempt to graft a more intersectional, holistic framework to introduce in the feminist and existential discourses, and to proffer a new intersectional holistic paradigm of discussing categories that do not limit creative productions. To frame this research, I will reflect on the politics of historical and contemporary South African society as it is reflected in the works of the chosen creative producers and theorists and to question how we respond as creative feminist existentialists to contemporary South African struggles and how such a lens can be activated as a creative-theoretical tool of investigation.
- Full Text:
- Date Issued: 2020