Exploring how the use of a mini-ecosystem enables and/or constrains grade 5 learners to make sense of scientific inquiry
- Authors: Tobias, Ruusa Taimi
- Date: 2022-10-14
- Subjects: Science Study and teaching (Elementary) Namibia , Health education (Elementary) Namibia , Education for sustainable development , Sensemaking , Inquiry-based learning Namibia , Terrariums , Social learning Namibia
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405423 , vital:70170
- Description: The Namibian Science curriculum clearly states that learning of science should be promoted through using inquiry-based approaches. However, it does not state how teachers should go about promoting inquiry-based approaches in their classrooms, especially in under-resourced rural schools. This is exacerbated in part by the fact that there is inadequate or lack of professional development for science teachers which focus in particular on promotion of inquiry-based approaches. As a result, science teachers tend to ignore inquiry-based approaches in their classrooms. It is against this background that my study sought to explore how the use of a ‘mini-ecosystem’ enables and/or constrains grade 5 learners from an under-resourced rural school to make sense of scientific inquiry. The study is underpinned by an interpretive paradigm. Within the interpretive paradigm, a qualitative case study approach, using the Predict-Explain-Explore-Observe-Explain (PEEOE) framework was adopted. This case study was carried out in an under-resourced rural Namibian school and the participants were grade 5 Natural Science and Health Education learners. I also invited a teacher from the school to be my critical friend and a participant observer. Data were generated using the Views About Scientific Inquiry (VASI) questionnaire, observations, focus group interviews and learners’ reflections. Vygotsky’s socio-cultural theory was my theoretical framework, and within this theory, I used mediation of learning, social interactions, the zone of proximal development and self-regulation as lenses to analyse my data. A thematic approach to data analysis was adopted. That is, qualitative data were analysed inductively to come up with sub-themes and thereafter common sub-themes were combined to form themes. The findings of the study revealed that the observation of mini-ecosystems enabled learners to interact and participate with each other in their respective groups. Moreover, learners were able to identify some scientific concepts such as evaporation, condensation, water cycle and rainfall. These findings are in contrast with the fact that they seemed to struggle to answer the VASI questionnaire that was conducted prior to observation. The study thus recommends that science teachers should make efforts to use easily accessible resources such as a ‘mini-ecosystem’ to promote scientific inquiry amongst their learners. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Tobias, Ruusa Taimi
- Date: 2022-10-14
- Subjects: Science Study and teaching (Elementary) Namibia , Health education (Elementary) Namibia , Education for sustainable development , Sensemaking , Inquiry-based learning Namibia , Terrariums , Social learning Namibia
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405423 , vital:70170
- Description: The Namibian Science curriculum clearly states that learning of science should be promoted through using inquiry-based approaches. However, it does not state how teachers should go about promoting inquiry-based approaches in their classrooms, especially in under-resourced rural schools. This is exacerbated in part by the fact that there is inadequate or lack of professional development for science teachers which focus in particular on promotion of inquiry-based approaches. As a result, science teachers tend to ignore inquiry-based approaches in their classrooms. It is against this background that my study sought to explore how the use of a ‘mini-ecosystem’ enables and/or constrains grade 5 learners from an under-resourced rural school to make sense of scientific inquiry. The study is underpinned by an interpretive paradigm. Within the interpretive paradigm, a qualitative case study approach, using the Predict-Explain-Explore-Observe-Explain (PEEOE) framework was adopted. This case study was carried out in an under-resourced rural Namibian school and the participants were grade 5 Natural Science and Health Education learners. I also invited a teacher from the school to be my critical friend and a participant observer. Data were generated using the Views About Scientific Inquiry (VASI) questionnaire, observations, focus group interviews and learners’ reflections. Vygotsky’s socio-cultural theory was my theoretical framework, and within this theory, I used mediation of learning, social interactions, the zone of proximal development and self-regulation as lenses to analyse my data. A thematic approach to data analysis was adopted. That is, qualitative data were analysed inductively to come up with sub-themes and thereafter common sub-themes were combined to form themes. The findings of the study revealed that the observation of mini-ecosystems enabled learners to interact and participate with each other in their respective groups. Moreover, learners were able to identify some scientific concepts such as evaporation, condensation, water cycle and rainfall. These findings are in contrast with the fact that they seemed to struggle to answer the VASI questionnaire that was conducted prior to observation. The study thus recommends that science teachers should make efforts to use easily accessible resources such as a ‘mini-ecosystem’ to promote scientific inquiry amongst their learners. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
Exploring integration for the topic of stoichiometry in South African natural sciences and physical sciences school curricula
- Authors: Mgolozeli, Kwanele
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405330 , vital:70162
- Description: Many developing countries, including South Africa, have identified the provision and implementation of strong science curricula as central to their developmental needs. Stoichiometry is a fundamental chemistry topic because the concepts involved form the basis of later topics such as chemical equilibrium, rates of reactions, redox reactions, and acid-base reactions. School students consistently demonstrate lack of understanding of stoichiometry-related concepts and skills such as the particulate nature of matter and related mathematical problem-solving. The poor performance of high school students in central science topics such as stoichiometry is problematic for their further study of chemistry and for the country meeting its need for science graduates. Successive examiner reports pointed to the lack of integration of stoichiometry concepts across the grades being the main problem. However, no study could be found which explores how stoichiometry is integrated in the South African Natural Sciences and Physical Sciences curriculum across the grades. This provided the rationale for the current study. The case study reported in this thesis thus aimed to explore integration of stoichiometry concepts in South African Natural Sciences and Physical Sciences school curricula. It involved document analysis as the method of collecting data. The research adopted the social realist paradigm, with its realist ontology and relativist epistemology. Legitimation Code Theory provided the theoretical framing. Chemistry concepts that are foundational to the understanding of stoichiometry according to literature, were chosen as root concepts for the concept mapping undertaken to identify types of integration. The concept maps revealed four stoichiometry integration themes: integration of stoichiometry concepts with symbols, integration of stoichiometry concepts with explanations, integration with applications in a chemistry context, and integration with an everyday context. These themes provided integration categories. A semantic gravity translation device was then developed for characterising the types of integration in terms of the degree of contextualisation. The results of this study show that stoichiometry integration of weaker semantic gravity is legitimated more strongly over other semantic gravity codes in the Natural Sciences and Physical Sciences curricula across all grade levels. While this has advantages in terms of knowledge-building potential, the consequence is that the integration occurs at very abstract levels that are far removed from learners’ everyday lives. The practical implication for curriculum developers involves increasing the instances of integration of stoichiometry concepts at stronger levels of semantic gravity, for a more even semantic gravity range of integration types. Natural Sciences and Physical Sciences teachers also need to source and include real-life examples for explanations and applications of stoichiometry concepts when teaching, in light of current curriculum documents focusing more on abstract forms of integration. Methodologically, this study contributes to the increased utility of semantic gravity through its exploration of integration in relation to knowledge-building potential of curriculum for hierarchical knowledge structures such as chemistry. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mgolozeli, Kwanele
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405330 , vital:70162
- Description: Many developing countries, including South Africa, have identified the provision and implementation of strong science curricula as central to their developmental needs. Stoichiometry is a fundamental chemistry topic because the concepts involved form the basis of later topics such as chemical equilibrium, rates of reactions, redox reactions, and acid-base reactions. School students consistently demonstrate lack of understanding of stoichiometry-related concepts and skills such as the particulate nature of matter and related mathematical problem-solving. The poor performance of high school students in central science topics such as stoichiometry is problematic for their further study of chemistry and for the country meeting its need for science graduates. Successive examiner reports pointed to the lack of integration of stoichiometry concepts across the grades being the main problem. However, no study could be found which explores how stoichiometry is integrated in the South African Natural Sciences and Physical Sciences curriculum across the grades. This provided the rationale for the current study. The case study reported in this thesis thus aimed to explore integration of stoichiometry concepts in South African Natural Sciences and Physical Sciences school curricula. It involved document analysis as the method of collecting data. The research adopted the social realist paradigm, with its realist ontology and relativist epistemology. Legitimation Code Theory provided the theoretical framing. Chemistry concepts that are foundational to the understanding of stoichiometry according to literature, were chosen as root concepts for the concept mapping undertaken to identify types of integration. The concept maps revealed four stoichiometry integration themes: integration of stoichiometry concepts with symbols, integration of stoichiometry concepts with explanations, integration with applications in a chemistry context, and integration with an everyday context. These themes provided integration categories. A semantic gravity translation device was then developed for characterising the types of integration in terms of the degree of contextualisation. The results of this study show that stoichiometry integration of weaker semantic gravity is legitimated more strongly over other semantic gravity codes in the Natural Sciences and Physical Sciences curricula across all grade levels. While this has advantages in terms of knowledge-building potential, the consequence is that the integration occurs at very abstract levels that are far removed from learners’ everyday lives. The practical implication for curriculum developers involves increasing the instances of integration of stoichiometry concepts at stronger levels of semantic gravity, for a more even semantic gravity range of integration types. Natural Sciences and Physical Sciences teachers also need to source and include real-life examples for explanations and applications of stoichiometry concepts when teaching, in light of current curriculum documents focusing more on abstract forms of integration. Methodologically, this study contributes to the increased utility of semantic gravity through its exploration of integration in relation to knowledge-building potential of curriculum for hierarchical knowledge structures such as chemistry. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
Exploring primary school mathematics teachers use of gamification in formative assessment: a case study
- Authors: Simelane, Thando
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405412 , vital:70169
- Description: Technology integration has gained much influence with the emergence of technological tools in educational areas. The vast resources and opportunities that technologies and the Internet have brought new approaches, strategies, and tools to assess learners' performance in many subject areas. Teachers have many computer/mobile device applications and learning management systems. Most teachers are trying new ways of integrating technology into the mathematics classroom to increase the quality of teaching and learning. Thus, this study explored how primary school mathematics teachers use Kahoot as a formative assessment tool. The study adopted an exploratory case study underpinned by the interpretive paradigm. It was conducted in a primary school in the Shiselweni Region in Swaziland. The participants were ten mathematics teachers teaching different grades at the school. Data was generated using observations, workshops, structured questionnaires, journal reflections and focus group interviews. The theoretical and analytical framework that underpinned this study was a combination of Davis' (1989) Technology Acceptance Model (TAM) and Mishra & Koehler's (2006) Technological Pedagogical Content Knowledge (TPACK) framework. The study results showed that the perceptions and attitudes of primary school mathematics teachers towards using Kahoot generally appear to be positive. The study also revealed that all the participants found Kahoot helpful and perceived it as easy to use. The study found that the provision of technical support for teachers; and financial support for schools to implement technology use in the classroom were enabling factors for using Kahoot as a formative assessment technology. Constraining factors were lack of high-speed internet connectivity; and lack of basic technological knowledge for using Kahoot in formative assessment. The study concluded that Kahoot increases learner motivation, engagement, attention, enjoyment, and knowledge retention. This study recommended the integration of Kahoot gamification into the mathematics curriculum.The study recommends that there is a need for schools to initiate the presence of technologies in mathematics classrooms and encourage teachers to integrate technologies assessment and teaching. The study suggest future research to explore use of Kahoot as a formative assessment technology in resource-constrained schooling contexts using multiple cases. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Simelane, Thando
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405412 , vital:70169
- Description: Technology integration has gained much influence with the emergence of technological tools in educational areas. The vast resources and opportunities that technologies and the Internet have brought new approaches, strategies, and tools to assess learners' performance in many subject areas. Teachers have many computer/mobile device applications and learning management systems. Most teachers are trying new ways of integrating technology into the mathematics classroom to increase the quality of teaching and learning. Thus, this study explored how primary school mathematics teachers use Kahoot as a formative assessment tool. The study adopted an exploratory case study underpinned by the interpretive paradigm. It was conducted in a primary school in the Shiselweni Region in Swaziland. The participants were ten mathematics teachers teaching different grades at the school. Data was generated using observations, workshops, structured questionnaires, journal reflections and focus group interviews. The theoretical and analytical framework that underpinned this study was a combination of Davis' (1989) Technology Acceptance Model (TAM) and Mishra & Koehler's (2006) Technological Pedagogical Content Knowledge (TPACK) framework. The study results showed that the perceptions and attitudes of primary school mathematics teachers towards using Kahoot generally appear to be positive. The study also revealed that all the participants found Kahoot helpful and perceived it as easy to use. The study found that the provision of technical support for teachers; and financial support for schools to implement technology use in the classroom were enabling factors for using Kahoot as a formative assessment technology. Constraining factors were lack of high-speed internet connectivity; and lack of basic technological knowledge for using Kahoot in formative assessment. The study concluded that Kahoot increases learner motivation, engagement, attention, enjoyment, and knowledge retention. This study recommended the integration of Kahoot gamification into the mathematics curriculum.The study recommends that there is a need for schools to initiate the presence of technologies in mathematics classrooms and encourage teachers to integrate technologies assessment and teaching. The study suggest future research to explore use of Kahoot as a formative assessment technology in resource-constrained schooling contexts using multiple cases. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
Exploring the diverse racialised responses to the ‘Ashwin Willemse incident’ through theories of race and coloniality of being
- Authors: Accom, Abner
- Date: 2022-10-14
- Subjects: Willemse, Ashwin, 1981- , Ethnic attitudes South Africa , Race awareness South Africa , Postcolonialism South Africa , South Africa Race relations , Decolonization South Africa , Racism in sports South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405908 , vital:70218
- Description: On 19 May 2018 Ashwin Willemse, a coloured Springbok rugby player walked off the SuperSport set, a DSTV sports program, during a live broadcast. He accused his white co-hosts Nick Mallet and Naas Botha (two white apartheid-era Springboks) of patronising him (SABC News, 2018; Eyewitness News, 2018). Responses to the Willemse incident reflected racial divisions in the country. It appeared that many white South Africans criticised Willemse’s behaviour, while many black South Africans stated that they could identify with his response to the subtle racisms experienced in everyday life, and which he claimed to have experienced on the SuperSport program (SABC News, 2018; Eyewitness News, 2018). The racialised media outcry led Professor Jonathan Jansen, to ask: “why do two groups of people, staring at the same event ‘see’ two different realities” (Maleka, 2018: 4)? This thesis probes possible answers to Jonathan Jansen’s question regarding the Ashwin Willemse walkout. The thesis explores and analyses the diverse racialised responses to the ‘Willemse walkout’ through race theories and ‘coloniality of being’. Qualitative research methods were used in the form of a reception analysis involving two racially homogenous (black and white) focus group interviews, two in-depth individual interviews with black research participants, three in-depth individual interviews with white research participants, and a sample of tweets from black and white commentators who had opinions about the ‘Willemse walkout’. The thesis concludes that most black research participants supported Willemse’s actions and most of the white people in the group disagreed with Willemse’s behaviour. Their various opinions were largely due to their different lived experiences which were a consequence of South Africa’s colonial history, apartheid, and racial discrimination. , Thesis (MA) -- Faculty of Humanities, School of Journalism and Media Studies, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Accom, Abner
- Date: 2022-10-14
- Subjects: Willemse, Ashwin, 1981- , Ethnic attitudes South Africa , Race awareness South Africa , Postcolonialism South Africa , South Africa Race relations , Decolonization South Africa , Racism in sports South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405908 , vital:70218
- Description: On 19 May 2018 Ashwin Willemse, a coloured Springbok rugby player walked off the SuperSport set, a DSTV sports program, during a live broadcast. He accused his white co-hosts Nick Mallet and Naas Botha (two white apartheid-era Springboks) of patronising him (SABC News, 2018; Eyewitness News, 2018). Responses to the Willemse incident reflected racial divisions in the country. It appeared that many white South Africans criticised Willemse’s behaviour, while many black South Africans stated that they could identify with his response to the subtle racisms experienced in everyday life, and which he claimed to have experienced on the SuperSport program (SABC News, 2018; Eyewitness News, 2018). The racialised media outcry led Professor Jonathan Jansen, to ask: “why do two groups of people, staring at the same event ‘see’ two different realities” (Maleka, 2018: 4)? This thesis probes possible answers to Jonathan Jansen’s question regarding the Ashwin Willemse walkout. The thesis explores and analyses the diverse racialised responses to the ‘Willemse walkout’ through race theories and ‘coloniality of being’. Qualitative research methods were used in the form of a reception analysis involving two racially homogenous (black and white) focus group interviews, two in-depth individual interviews with black research participants, three in-depth individual interviews with white research participants, and a sample of tweets from black and white commentators who had opinions about the ‘Willemse walkout’. The thesis concludes that most black research participants supported Willemse’s actions and most of the white people in the group disagreed with Willemse’s behaviour. Their various opinions were largely due to their different lived experiences which were a consequence of South Africa’s colonial history, apartheid, and racial discrimination. , Thesis (MA) -- Faculty of Humanities, School of Journalism and Media Studies, 2022
- Full Text:
- Date Issued: 2022-10-14
Exploring the influence of student protests on organisational citizenship behaviour of academics and support mechanisms in higher learning institutions
- Authors: Mayekiso, Sinovuyo
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406198 , vital:70248
- Description: Embargoed. To be released in 2024. , Thesis (MA) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mayekiso, Sinovuyo
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406198 , vital:70248
- Description: Embargoed. To be released in 2024. , Thesis (MA) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-10-14
Exploring the lexical and semantic access afforded by novice and experienced Namibian physical science teachers’ talk during electricity and magnetism lessons
- Authors: Muzambani, Efraim Hiamueze
- Date: 2022-10-14
- Subjects: Knowledge, Theory of , Education, Secondary Aims and objectives Namibia , Science Study and teaching (Secondary) Namibia , Systemic functional linguistics , Lexical density , Electricity Study and teaching (Secondary) Namibia , Magnetism Study and teaching (Secondary) Namibia
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405346 , vital:70163
- Description: Challenges to learners’ meaning-making in the topic of electricity and magnetism contributes to underperformance in grade 10 Physical Science in Namibian schools. Teacher talk in content-based classrooms not only contributes to learners’ language development (Gibbons, 2003), but also facilitates meaning-making and cumulative knowledge-building (Halliday, 1999). However, it is possible that there are differences between the classrooms talk of novice and experienced Namibian Physical Science teachers. An understanding of differences between experienced and novice Namibian science teacher talk could inform teacher training and professional development and potentially help improve learners’ meaning-making in topics such as electricity and magnetism. However, no study could be found in the Namibian context which explored whether novice and experienced teacher talk afforded similar semantic and lexical access to meaning-making. This research gap provided a strong rationale for undertaking the study reported in this thesis. The study sought to investigate the extent to which novice and experienced grade 10 Namibian Physical Science teachers’ classroom talk provides semantic and lexical access to learners for the topic of electricity and magnetism. The research is informed by Legitimation Code Theory (LCT) and Systemic Functional Linguistics (SFL). Research has shown that the two theories are complementary and can be used to characterize teachers’ pedagogical practices (Maton, 2014). A quantitative case study methodology was followed in this study with LCT’s semantic density and SFL’s lexical density as analytical tools to analyze the two teachers’ classroom talk. The results from a t-test for semantic density show that there is a significant difference in the means for “semantic density waving” criterion (t-value of -2.331; p-value for 2 tail test at 95% level of 0.0040) and for the “linking downward escalators or single references” criterion (t-value of 4.649; p-value for 2 tail test at 95% level of 0.001) of teacher talk by the teachers. The overall results for semantic density indicate that the experienced teacher affords better epistemological access through semantic waves than the novice teacher, whereas the novice teacher affords better epistemological access through semantic range and semantic flow. In terms of lexical density, both teachers afforded similar access, characterized by their talk veering towards the level of information density associated with written text. The study makes a methodological contribution to science education research through its characterization of novice and experienced teachers’ talk in terms of semantic waves and lexical density. This study also provides empirical insight into the differences between language use by novice and experienced Namibian Physical Science teachers, which can inform the work of educational institutions, advisory and inspectorate services in the ministry of education, and school managers. Relevant Namibian stakeholders are encouraged to consider including the topics of semantic density and lexical density, in continuous professional development programmes towards improving the meaning-making affordances of science teachers’ talk. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Muzambani, Efraim Hiamueze
- Date: 2022-10-14
- Subjects: Knowledge, Theory of , Education, Secondary Aims and objectives Namibia , Science Study and teaching (Secondary) Namibia , Systemic functional linguistics , Lexical density , Electricity Study and teaching (Secondary) Namibia , Magnetism Study and teaching (Secondary) Namibia
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405346 , vital:70163
- Description: Challenges to learners’ meaning-making in the topic of electricity and magnetism contributes to underperformance in grade 10 Physical Science in Namibian schools. Teacher talk in content-based classrooms not only contributes to learners’ language development (Gibbons, 2003), but also facilitates meaning-making and cumulative knowledge-building (Halliday, 1999). However, it is possible that there are differences between the classrooms talk of novice and experienced Namibian Physical Science teachers. An understanding of differences between experienced and novice Namibian science teacher talk could inform teacher training and professional development and potentially help improve learners’ meaning-making in topics such as electricity and magnetism. However, no study could be found in the Namibian context which explored whether novice and experienced teacher talk afforded similar semantic and lexical access to meaning-making. This research gap provided a strong rationale for undertaking the study reported in this thesis. The study sought to investigate the extent to which novice and experienced grade 10 Namibian Physical Science teachers’ classroom talk provides semantic and lexical access to learners for the topic of electricity and magnetism. The research is informed by Legitimation Code Theory (LCT) and Systemic Functional Linguistics (SFL). Research has shown that the two theories are complementary and can be used to characterize teachers’ pedagogical practices (Maton, 2014). A quantitative case study methodology was followed in this study with LCT’s semantic density and SFL’s lexical density as analytical tools to analyze the two teachers’ classroom talk. The results from a t-test for semantic density show that there is a significant difference in the means for “semantic density waving” criterion (t-value of -2.331; p-value for 2 tail test at 95% level of 0.0040) and for the “linking downward escalators or single references” criterion (t-value of 4.649; p-value for 2 tail test at 95% level of 0.001) of teacher talk by the teachers. The overall results for semantic density indicate that the experienced teacher affords better epistemological access through semantic waves than the novice teacher, whereas the novice teacher affords better epistemological access through semantic range and semantic flow. In terms of lexical density, both teachers afforded similar access, characterized by their talk veering towards the level of information density associated with written text. The study makes a methodological contribution to science education research through its characterization of novice and experienced teachers’ talk in terms of semantic waves and lexical density. This study also provides empirical insight into the differences between language use by novice and experienced Namibian Physical Science teachers, which can inform the work of educational institutions, advisory and inspectorate services in the ministry of education, and school managers. Relevant Namibian stakeholders are encouraged to consider including the topics of semantic density and lexical density, in continuous professional development programmes towards improving the meaning-making affordances of science teachers’ talk. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
Exploring Ubuntu as service leadership competency
- Authors: Bangushe, Anele Greatjoy
- Date: 2022-10-14
- Subjects: Leadership Moral and ethical aspects , Ubuntu (Philosophy) , Methodist Church of South Africa , Servant leadership South Africa Makhanda , Christian leadership South Africa Makhanda , Community leadership South Africa Makhanda , Critical incident technique
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/380743 , vital:67488
- Description: This is a case study conducted in the Methodist Church of Southern Africa (MCSA), Grahamstown, in the Eastern Cape. Against the backdrop of identifying and conceptualising ethically oriented leadership competencies, the purpose of this study was to explore service as a leadership competency. The literature reviewed in this research underscored the importance of effective and ethical leadership, but critiqued the Westernised, individualistic orientation of the conceptualisation of service as a leadership competency. Based on a review of the literature, this study proposes that when African leaders are in leadership four components of Ubuntu are involved when they exercise service as a leadership competency. These components are collective consideration, collective compassion, community server and Ubuntu humility. The main aim of this study is to investigate if leaders display these four components when exercising service towards their followers, and if so, how, and why they do so. A conceptual framework of components of Ubuntu, which culminated in research themes and propositions, were produced from the literature chapter. A qualitative research method was adopted in this study in which eight participants were selected through convenience sampling for this case study. One minister and seven Vice-Presidents of various organisations in the Methodist Church were interviewed. Semi-structured interviews were conducted for data collection and a deductive thematic analysis approach was employed to analyse data. Also, the critical incident technique (CIT) was utilised to structure interview questions, which is best fitting to solicit complex and comprehensive data from the interviewees. In its findings, the study confirmed the presence of the four components of Ubuntu, but several delimitations and limitations are acknowledged. Nevertheless, the study has made some contribution to understanding the display of service as a leadership competency in an African context. The implications for management practice are considered and recommendations made for future research. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Bangushe, Anele Greatjoy
- Date: 2022-10-14
- Subjects: Leadership Moral and ethical aspects , Ubuntu (Philosophy) , Methodist Church of South Africa , Servant leadership South Africa Makhanda , Christian leadership South Africa Makhanda , Community leadership South Africa Makhanda , Critical incident technique
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/380743 , vital:67488
- Description: This is a case study conducted in the Methodist Church of Southern Africa (MCSA), Grahamstown, in the Eastern Cape. Against the backdrop of identifying and conceptualising ethically oriented leadership competencies, the purpose of this study was to explore service as a leadership competency. The literature reviewed in this research underscored the importance of effective and ethical leadership, but critiqued the Westernised, individualistic orientation of the conceptualisation of service as a leadership competency. Based on a review of the literature, this study proposes that when African leaders are in leadership four components of Ubuntu are involved when they exercise service as a leadership competency. These components are collective consideration, collective compassion, community server and Ubuntu humility. The main aim of this study is to investigate if leaders display these four components when exercising service towards their followers, and if so, how, and why they do so. A conceptual framework of components of Ubuntu, which culminated in research themes and propositions, were produced from the literature chapter. A qualitative research method was adopted in this study in which eight participants were selected through convenience sampling for this case study. One minister and seven Vice-Presidents of various organisations in the Methodist Church were interviewed. Semi-structured interviews were conducted for data collection and a deductive thematic analysis approach was employed to analyse data. Also, the critical incident technique (CIT) was utilised to structure interview questions, which is best fitting to solicit complex and comprehensive data from the interviewees. In its findings, the study confirmed the presence of the four components of Ubuntu, but several delimitations and limitations are acknowledged. Nevertheless, the study has made some contribution to understanding the display of service as a leadership competency in an African context. The implications for management practice are considered and recommendations made for future research. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
- Full Text:
- Date Issued: 2022-10-14
Factors constraining and enabling the adoption of a disruptive technology by African small, micro, and medium enterprises for the Fourth Industrial Revolution: The case of mobile money
- Authors: Tarr, Dillon
- Date: 2022-10-14
- Subjects: Disruptive technologies , Mobile commerce , Industry 4.0 , Small business Africa, Sub-Saharan , Diffusion of innovations Africa, Sub-Saharan , Technological innovations Management
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/357709 , vital:64770
- Description: The Fourth Industrial Revolution (4IR) is set to disrupt existing economic and social structures through the use of cyber-physical systems that result from a fusion of the digital, biological, and physical spheres. The fifth and current long wave of innovation is going through such a digital revolution in the ongoing deployment period which is being driven by the generalpurpose technologies of Artificial Intelligence and the Internet of Things, among other cyberphysical systems. The impact of mobile money in the access of financial services has shown how disruptive incremental innovations in mobile and digital technologies can be. The transformational power of mobile money in financial access is due to its use as an accessible financial tool that utilizes mobile devices to send and/or receive money over great distances. With the 4IR looming, this thesis determines the factors that enable and constrain the adoption of a disruptive technology amongst Sub-Saharan African small, micro, and medium enterprises (SMMEs). Therefore, due to its impact on financial inclusion and the formalization of SMMEs, mobile money is used as an indicator for the adoption of 4IR disruptive digital technologies. The adoption of mobile money was evaluated using secondary data from a survey conducted by Research ICT Africa, which surveyed 4408 SMMEs in nine African countries. The Diffusion of Innovations (DOI) model and the Unified Theory of Acceptance and Use of Technology (UTAUT) model were used to identify the factors enabling and constraining the adoption of a disruptive technology, in this case mobile money. Factors included gender, vocational training, business skills training, tertiary education, services, performance expectancy, social media, location, and nine African countries (Kenya, Mozambique, Ghana, Nigeria, Rwanda, South Africa, Tanzania, Uganda, and Senegal). The factors were grouped into owner characteristics, firm attributes and country attributes. SMME owners with business skills (49%) showed the highest level of adoption in terms of owner characteristics, Kenyan SMMEs (21%) had the highest adoption between the countries surveyed, and social media (62%) showed the highest adoption in terms of firm attributes followed by the formal variable (47%). In general, only 29% of SMMEs surveyed adopted mobile money. The study found that women SMME owners were more likely to be affected by business formality when adopting a disruptive technology compared to male owned SMMEs. This is because informality often exacerbates other barriers/challenges women face such as lower access to finance, lower ability to exercise property, business, and labour rights, and lower visibility. The results also demonstrate that vocational training is more important than general tertiary education for the ii adoption of a disruptive technology such as mobile money. Furthermore, when using social media as a tool for business advice SMME owners were more likely to adopt the disruptive technology. The study suggests that to encourage African SMMEs to adequately adopt disruptive technologies of the 4IR, more women owned SMMEs need to enter the formal economy, and vocational training targeted at business skills must be promoted amongst all SMME owners. Eastern African SMMEs were found to be more likely to adopt mobile money compared to other African regions. The finding demonstrates the need for more African countries (particularly outside of the Eastern African region) to encourage innovation by addressing the four enablers of mobile connectivity (i.e. infrastructure, affordability, consumer readiness, and mobile services) which will in effect lead to economic growth and development. The study shows that to address country/regional differences, in addition to building the required infrastructure in terms of mobile internet connectivity, countries should increase the local relevancy of disruptive technologies between SMMEs. To achieve this the study suggests increasing mobile social media penetration rates. This is because when social media is used as a tool for business advice SMME owners are more likely to adopt a disruptive technology (as is the case with mobile money) due to the social influence of social media. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Tarr, Dillon
- Date: 2022-10-14
- Subjects: Disruptive technologies , Mobile commerce , Industry 4.0 , Small business Africa, Sub-Saharan , Diffusion of innovations Africa, Sub-Saharan , Technological innovations Management
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/357709 , vital:64770
- Description: The Fourth Industrial Revolution (4IR) is set to disrupt existing economic and social structures through the use of cyber-physical systems that result from a fusion of the digital, biological, and physical spheres. The fifth and current long wave of innovation is going through such a digital revolution in the ongoing deployment period which is being driven by the generalpurpose technologies of Artificial Intelligence and the Internet of Things, among other cyberphysical systems. The impact of mobile money in the access of financial services has shown how disruptive incremental innovations in mobile and digital technologies can be. The transformational power of mobile money in financial access is due to its use as an accessible financial tool that utilizes mobile devices to send and/or receive money over great distances. With the 4IR looming, this thesis determines the factors that enable and constrain the adoption of a disruptive technology amongst Sub-Saharan African small, micro, and medium enterprises (SMMEs). Therefore, due to its impact on financial inclusion and the formalization of SMMEs, mobile money is used as an indicator for the adoption of 4IR disruptive digital technologies. The adoption of mobile money was evaluated using secondary data from a survey conducted by Research ICT Africa, which surveyed 4408 SMMEs in nine African countries. The Diffusion of Innovations (DOI) model and the Unified Theory of Acceptance and Use of Technology (UTAUT) model were used to identify the factors enabling and constraining the adoption of a disruptive technology, in this case mobile money. Factors included gender, vocational training, business skills training, tertiary education, services, performance expectancy, social media, location, and nine African countries (Kenya, Mozambique, Ghana, Nigeria, Rwanda, South Africa, Tanzania, Uganda, and Senegal). The factors were grouped into owner characteristics, firm attributes and country attributes. SMME owners with business skills (49%) showed the highest level of adoption in terms of owner characteristics, Kenyan SMMEs (21%) had the highest adoption between the countries surveyed, and social media (62%) showed the highest adoption in terms of firm attributes followed by the formal variable (47%). In general, only 29% of SMMEs surveyed adopted mobile money. The study found that women SMME owners were more likely to be affected by business formality when adopting a disruptive technology compared to male owned SMMEs. This is because informality often exacerbates other barriers/challenges women face such as lower access to finance, lower ability to exercise property, business, and labour rights, and lower visibility. The results also demonstrate that vocational training is more important than general tertiary education for the ii adoption of a disruptive technology such as mobile money. Furthermore, when using social media as a tool for business advice SMME owners were more likely to adopt the disruptive technology. The study suggests that to encourage African SMMEs to adequately adopt disruptive technologies of the 4IR, more women owned SMMEs need to enter the formal economy, and vocational training targeted at business skills must be promoted amongst all SMME owners. Eastern African SMMEs were found to be more likely to adopt mobile money compared to other African regions. The finding demonstrates the need for more African countries (particularly outside of the Eastern African region) to encourage innovation by addressing the four enablers of mobile connectivity (i.e. infrastructure, affordability, consumer readiness, and mobile services) which will in effect lead to economic growth and development. The study shows that to address country/regional differences, in addition to building the required infrastructure in terms of mobile internet connectivity, countries should increase the local relevancy of disruptive technologies between SMMEs. To achieve this the study suggests increasing mobile social media penetration rates. This is because when social media is used as a tool for business advice SMME owners are more likely to adopt a disruptive technology (as is the case with mobile money) due to the social influence of social media. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
Fractured flowers
- Authors: Cunningham, Cornelia
- Date: 2022-10-14
- Subjects: Creative writing (Higher education) South Africa , Diaries -- Authorship , South African essays (English) 21st century , Books Reviews , South African fiction (English) 21st century
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406226 , vital:70250
- Description: This portfolio contains extracts of my reflective journals that I wrote throughout the course of the year. My poetics essay, four book reviews, community engagement report and my reflection regarding the reader report is also attached. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Cunningham, Cornelia
- Date: 2022-10-14
- Subjects: Creative writing (Higher education) South Africa , Diaries -- Authorship , South African essays (English) 21st century , Books Reviews , South African fiction (English) 21st century
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406226 , vital:70250
- Description: This portfolio contains extracts of my reflective journals that I wrote throughout the course of the year. My poetics essay, four book reviews, community engagement report and my reflection regarding the reader report is also attached. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2022
- Full Text:
- Date Issued: 2022-10-14
Fucoidans from South African brown seaweeds: establishing the link between their structure and biological properties (anti-diabetic and anti-cancer activities)
- Authors: Mabate, Blessing
- Date: 2022-10-14
- Subjects: Fucoidan , Diabetes Treatment , Cancer Treatment , Brown algae
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365677 , vital:65775 , DOI https://doi.org/10.21504/10962/365677
- Description: Type 2 diabetes mellitus (T2DM) and cancer are major non-communicable diseases causing a heavy morbidity-mortality and economic burden globally. The therapeutic efforts in managing these diseases are primarily chemotherapeutic and are associated with demerits, including side effects and toxicity, limiting the prescribed amounts. These dosage limits may cause drug resistance, another major challenge in maintaining quality global health. The pursuit of novel natural bioproducts is a reasonable strategy to add to the arsenal against T2DM and cancer. Fucoidans, sulphated fucose polysaccharides abundant in brown seaweeds, have recently become popular for their biological activities, including anti-diabetic and anti-cancer properties. However, endemic South African brown seaweeds have not been adequately explored. Therefore, this study sought to characterise fucoidans extracted from South African brown seaweeds and elucidate their structure to their biological activities. Also, this study highlighted carbohydrate and glucose metabolism as major target processes in the control efforts of T2DM and cancer using fucoidans. Harvested brown seaweeds were identified as Ecklonia radiata and Sargassum elegans. E. maxima was kindly donated by KelpX. The fucoidans were then extracted using hot water, EDTA assisted, and acid extraction protocols. The integrity of the extracted fucoidan was confirmed through structural analysis using FTIR, NMR and TGA. The fucoidan extracts were then chemically characterised to determine their carbohydrate and monosaccharide composition and sulphate content. The characterised fucoidans were profiled for inhibiting the major amylolytic enzymes, namely α-amylase and α-glucosidase. The mode of inhibition by fucoidans and synergy experiments with the commercial anti-diabetic drug acarbose were also investigated. Furthermore, the fucoidans were screened for potential anti-cancer activities on the human colorectal HCT116 cancer cell line. The cytotoxicity of fucoidans was quantified using the resazurin assay. The effect of fucoidan on HCT116 cell adhesion on the tissue culture plastic was also investigated using the crystal violet-based cell adhesion assay. In addition, cancer antimigration properties of fucoidans were also investigated using 2D wound healing and 3D spheroid-based assays. Furthermore, the long-term survival of HCT116 cells was investigated through the clonogenic assay after treatment with fucoidans. Lastly, glucose uptake and lactate export assays revealed the influence of fucoidan on glucose uptake and the glycolytic flux of HCT116 cells. Fucoidans were successfully extracted with a yield between 2.2% and 14.2% on a dry weight basis. EDTA extracts produced the highest yields than the water and the acid extracts. Ecklonia spp. fucoidans displayed the highest total carbohydrate content, with glucose and galactose being the major monosaccharides. S. elegans and commercial Fucus vesiculosus had lower carbohydrate contents but contained more sulphates than the Ecklonia spp. fucoidans. Furthermore, the extracted fucoidan contained little to no contaminants, including proteins, phenolics and uronic acids. In addition, the extracted fucoidans were determined to be >100 kDa through ultracentrifugation. Mass spectrometry also detected the most abundant peak for all fucoidans to be around 700 Da (m/z). Extracted fucoidans inhibited the activity of α-glucosidase more strongly than the commercial anti-diabetic agent acarbose but were inactive on α-amylase. Fucoidans were also shown to be mixed inhibitors of α-glucosidase. Compellingly, fucoidans synergistically inhibited α-glucosidase in combination with the anti-diabetic agent acarbose, highlighting prospects for combination therapy. Finally, fucoidans demonstrated some anti-proliferative characteristics on HCT116 cancer cells by inhibiting their ability to adhere to the tissue culture plate matrix. Furthermore, some fucoidan extracts inhibited the migration of HCT116 cancer cells from 3D spheroids. Some of our fucoidan extracts also inhibited HCT116 colony formation, demonstrating inhibition of long-term cell survival. The E. maxima water extract also inhibited glucose uptake by HCT116 cells, thereby influencing the glycolytic flux. In conclusion, biologically active fucoidans were successfully extracted from South African brown seaweeds. These fucoidans demonstrated anti-diabetic and anti-cancer properties, revealing their relevance as potential drugs for these diseases. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mabate, Blessing
- Date: 2022-10-14
- Subjects: Fucoidan , Diabetes Treatment , Cancer Treatment , Brown algae
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365677 , vital:65775 , DOI https://doi.org/10.21504/10962/365677
- Description: Type 2 diabetes mellitus (T2DM) and cancer are major non-communicable diseases causing a heavy morbidity-mortality and economic burden globally. The therapeutic efforts in managing these diseases are primarily chemotherapeutic and are associated with demerits, including side effects and toxicity, limiting the prescribed amounts. These dosage limits may cause drug resistance, another major challenge in maintaining quality global health. The pursuit of novel natural bioproducts is a reasonable strategy to add to the arsenal against T2DM and cancer. Fucoidans, sulphated fucose polysaccharides abundant in brown seaweeds, have recently become popular for their biological activities, including anti-diabetic and anti-cancer properties. However, endemic South African brown seaweeds have not been adequately explored. Therefore, this study sought to characterise fucoidans extracted from South African brown seaweeds and elucidate their structure to their biological activities. Also, this study highlighted carbohydrate and glucose metabolism as major target processes in the control efforts of T2DM and cancer using fucoidans. Harvested brown seaweeds were identified as Ecklonia radiata and Sargassum elegans. E. maxima was kindly donated by KelpX. The fucoidans were then extracted using hot water, EDTA assisted, and acid extraction protocols. The integrity of the extracted fucoidan was confirmed through structural analysis using FTIR, NMR and TGA. The fucoidan extracts were then chemically characterised to determine their carbohydrate and monosaccharide composition and sulphate content. The characterised fucoidans were profiled for inhibiting the major amylolytic enzymes, namely α-amylase and α-glucosidase. The mode of inhibition by fucoidans and synergy experiments with the commercial anti-diabetic drug acarbose were also investigated. Furthermore, the fucoidans were screened for potential anti-cancer activities on the human colorectal HCT116 cancer cell line. The cytotoxicity of fucoidans was quantified using the resazurin assay. The effect of fucoidan on HCT116 cell adhesion on the tissue culture plastic was also investigated using the crystal violet-based cell adhesion assay. In addition, cancer antimigration properties of fucoidans were also investigated using 2D wound healing and 3D spheroid-based assays. Furthermore, the long-term survival of HCT116 cells was investigated through the clonogenic assay after treatment with fucoidans. Lastly, glucose uptake and lactate export assays revealed the influence of fucoidan on glucose uptake and the glycolytic flux of HCT116 cells. Fucoidans were successfully extracted with a yield between 2.2% and 14.2% on a dry weight basis. EDTA extracts produced the highest yields than the water and the acid extracts. Ecklonia spp. fucoidans displayed the highest total carbohydrate content, with glucose and galactose being the major monosaccharides. S. elegans and commercial Fucus vesiculosus had lower carbohydrate contents but contained more sulphates than the Ecklonia spp. fucoidans. Furthermore, the extracted fucoidan contained little to no contaminants, including proteins, phenolics and uronic acids. In addition, the extracted fucoidans were determined to be >100 kDa through ultracentrifugation. Mass spectrometry also detected the most abundant peak for all fucoidans to be around 700 Da (m/z). Extracted fucoidans inhibited the activity of α-glucosidase more strongly than the commercial anti-diabetic agent acarbose but were inactive on α-amylase. Fucoidans were also shown to be mixed inhibitors of α-glucosidase. Compellingly, fucoidans synergistically inhibited α-glucosidase in combination with the anti-diabetic agent acarbose, highlighting prospects for combination therapy. Finally, fucoidans demonstrated some anti-proliferative characteristics on HCT116 cancer cells by inhibiting their ability to adhere to the tissue culture plate matrix. Furthermore, some fucoidan extracts inhibited the migration of HCT116 cancer cells from 3D spheroids. Some of our fucoidan extracts also inhibited HCT116 colony formation, demonstrating inhibition of long-term cell survival. The E. maxima water extract also inhibited glucose uptake by HCT116 cells, thereby influencing the glycolytic flux. In conclusion, biologically active fucoidans were successfully extracted from South African brown seaweeds. These fucoidans demonstrated anti-diabetic and anti-cancer properties, revealing their relevance as potential drugs for these diseases. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Functional biogeography: evaluating community assemblage patterns and ecosystem functioning in intertidal systems using trait-based approaches
- Authors: Gusha, Molline Natanah C
- Date: 2022-10-14
- Subjects: Biogeography , Marine algae , Benthic ecology , Invertebrates , Functional redundancy , Ocean temperature , Biology Classification
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365792 , vital:65790 , DOI https://doi.org/10.21504/10962/365792
- Description: Analyses of taxonomic diversity patterns within coastal systems has been critical in the development of the theory of biogeography. Increasing evidence, however, shows that the variety of functions that species perform in ecosystems (rather than their taxonomic identity) is a better predictor of the influence of the environment on the species. This information has been useful in predictive ecology leading to the development of trait-based approaches (TBA). Until the late 1970s, however, limited effort (particularly in marine systems) was channeled towards patterns in functional species traits and how they may be affected by changes in environmental gradients. Here, I mapped the functional biogeography of the South African coastline based on a suite of species' reproduction and development traits. Because species composition is one of the key tools used by zoogeographers to map species distribution patterns, I expected lower variability in trait composition within main biogeographic regions than in intervening transition zones based on the habitat templet theory and following the biomass ratio and limiting similarity hypotheses. In brief, the habitat templet theory proposes that “the habitat provides a templet upon which evolution forges species characteristics”, while the biomass ratio hypothesis assumes that the most abundant species traits determine ecosystem functioning. The limiting similarity hypothesis also sometimes referred to as the niche complementarity hypothesis, however, predicts that species can coexist if their niches complement one another. In light of the habitat being an evolutionary templet, abiotic and biotic habitat patterns were measured as nearshore SST and chlorophyll-a gradients, respectively. I expected the SST gradient to act as the stronger key filter of trait diversification because temperature is often considered the most influential environmental factor affecting species survival with seasonality of SST affecting the timing of spawning and along with food availability, possibly influencing fecundity. Functional trait data were thus compiled for macroinvertebrate species collected from fifty-two rocky shore sites from three main bioregions (east, south, and west) and two transition zones (south-west and south-east). Biological trait analysis and functional diversity indices were used to evaluate how traits related to species development and reproduction respond to temperature and chlorophyll -a (used as a proxy for food availability) gradients along the coastline. GLMM and hierarchical cluster analyses showed distinct patterns/shifts in SST and chlorophyll-a gradients across bioregions, with two main breaks in SST separating the east and south-east overlap (SEO) bioregions from the south, south-west overlap (SWO) and west bioregions. In contrast, chlorophyll-a exhibited three major breaks with the east, SEO–south–SWO, and west clustering independently of each other. The RLQ analysis (a type of co-inertia analysis) which simultaneously ordinates 3-matrix datasets [i.e., (environment × site[R]), (species × site[L]) and (species × traits [Q])] showed that the higher SST gradient on the east and SEO promoted higher abundance and biomass of simultaneous hermaphrodites while higher chlorophyll-a gradients on the SWO and west coasts strongly promoted reproductive maturity at larger-sizes. The combined fourth-corner analyses showed that the modalities within the development trait domain responding to chlorophyll-a gradients primarily included filter feeders, sessile and swimming species and also species living on the infratidal zone. In addition, the reproduction trait domain showed higher sensitivity and association to differences in chlorophyll-a and SST gradients than development traits. Overall, SST and chlorophyll-a gradients influenced the distribution of the most dominant traits as indicated by shifts in community-weighted mean trait values across bioregions. This suggests the importance of habitat filtering on coastal species reproduction. A separate study evaluating the influence of large-scale biogeographic effects vs the micro-scale biogenic habitat structure offered by coralline seaweeds across 24 sites revealed some notable effects of both factors on the diversity and abundance of macroalgal epifauna. There was a notable biogeographic influence on epifauna, with the SEO recording the highest epifaunal species richness and abundance, followed by the south coast, then the SWO and lastly the west coast. In addition, the total biomass gradient of the corallines followed a similar trend. The epifauna however, showed no host-specificity, illustrating that epifauna may not be species–centric as commonly assumed, and the higher diversity of epifaunal diversity may well be simply because those corallines are the available habitat within the sampled part of the coastline. Lastly, macroinvertebrate trait distribution on the South African coastline confirms that the habitat, particularly the biotic filter (in this case chl-a) provides a templet upon which evolution forges species traits. However, since temperature is a proxy for nutrient availability (cold upwelling brings nutrients), then temperature drives chlorophyll-a. Subsequently this means the abiotic component indirectly drives trait distribution by influencing the biotic environment (chl-a). For epifauna species, also, the coralline diversity and composition can also be regarded as a biotic filter influencing the epifaunal abundances and composition across different bioregions. Moreover, since temperature is regarded as a conservative trait in seaweeds, temperature tolerance defines the biogeographical boundaries of seaweeds, therefore temperature may be indirectly affecting epifauna abundances through coralline species diversity and biomass. In summary, considering the deterministic processes governing ecosystem functioning and community assemblage, the mass ratio and limiting similarity hypotheses showed complementary effects. Different bioregions provided variable support for these two hypotheses, but overall, the mass ratio hypothesis (weighted by species biomass) received stronger support and may be more meaningful to the interpretation of ecosystem functioning and persistence within rocky shore systems. Lastly, although, the SWO showed some of the characteristics of a subtraction zone based on the relatively low abundance, diversity, and biomass measures. Nonetheless, there was evidence of high functional redundancy across all other four bioregions. This suggests that in the context of development and reproduction traits, the rocky shore ecosystem along the SA coastline may be functionally stable at this stage. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Gusha, Molline Natanah C
- Date: 2022-10-14
- Subjects: Biogeography , Marine algae , Benthic ecology , Invertebrates , Functional redundancy , Ocean temperature , Biology Classification
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365792 , vital:65790 , DOI https://doi.org/10.21504/10962/365792
- Description: Analyses of taxonomic diversity patterns within coastal systems has been critical in the development of the theory of biogeography. Increasing evidence, however, shows that the variety of functions that species perform in ecosystems (rather than their taxonomic identity) is a better predictor of the influence of the environment on the species. This information has been useful in predictive ecology leading to the development of trait-based approaches (TBA). Until the late 1970s, however, limited effort (particularly in marine systems) was channeled towards patterns in functional species traits and how they may be affected by changes in environmental gradients. Here, I mapped the functional biogeography of the South African coastline based on a suite of species' reproduction and development traits. Because species composition is one of the key tools used by zoogeographers to map species distribution patterns, I expected lower variability in trait composition within main biogeographic regions than in intervening transition zones based on the habitat templet theory and following the biomass ratio and limiting similarity hypotheses. In brief, the habitat templet theory proposes that “the habitat provides a templet upon which evolution forges species characteristics”, while the biomass ratio hypothesis assumes that the most abundant species traits determine ecosystem functioning. The limiting similarity hypothesis also sometimes referred to as the niche complementarity hypothesis, however, predicts that species can coexist if their niches complement one another. In light of the habitat being an evolutionary templet, abiotic and biotic habitat patterns were measured as nearshore SST and chlorophyll-a gradients, respectively. I expected the SST gradient to act as the stronger key filter of trait diversification because temperature is often considered the most influential environmental factor affecting species survival with seasonality of SST affecting the timing of spawning and along with food availability, possibly influencing fecundity. Functional trait data were thus compiled for macroinvertebrate species collected from fifty-two rocky shore sites from three main bioregions (east, south, and west) and two transition zones (south-west and south-east). Biological trait analysis and functional diversity indices were used to evaluate how traits related to species development and reproduction respond to temperature and chlorophyll -a (used as a proxy for food availability) gradients along the coastline. GLMM and hierarchical cluster analyses showed distinct patterns/shifts in SST and chlorophyll-a gradients across bioregions, with two main breaks in SST separating the east and south-east overlap (SEO) bioregions from the south, south-west overlap (SWO) and west bioregions. In contrast, chlorophyll-a exhibited three major breaks with the east, SEO–south–SWO, and west clustering independently of each other. The RLQ analysis (a type of co-inertia analysis) which simultaneously ordinates 3-matrix datasets [i.e., (environment × site[R]), (species × site[L]) and (species × traits [Q])] showed that the higher SST gradient on the east and SEO promoted higher abundance and biomass of simultaneous hermaphrodites while higher chlorophyll-a gradients on the SWO and west coasts strongly promoted reproductive maturity at larger-sizes. The combined fourth-corner analyses showed that the modalities within the development trait domain responding to chlorophyll-a gradients primarily included filter feeders, sessile and swimming species and also species living on the infratidal zone. In addition, the reproduction trait domain showed higher sensitivity and association to differences in chlorophyll-a and SST gradients than development traits. Overall, SST and chlorophyll-a gradients influenced the distribution of the most dominant traits as indicated by shifts in community-weighted mean trait values across bioregions. This suggests the importance of habitat filtering on coastal species reproduction. A separate study evaluating the influence of large-scale biogeographic effects vs the micro-scale biogenic habitat structure offered by coralline seaweeds across 24 sites revealed some notable effects of both factors on the diversity and abundance of macroalgal epifauna. There was a notable biogeographic influence on epifauna, with the SEO recording the highest epifaunal species richness and abundance, followed by the south coast, then the SWO and lastly the west coast. In addition, the total biomass gradient of the corallines followed a similar trend. The epifauna however, showed no host-specificity, illustrating that epifauna may not be species–centric as commonly assumed, and the higher diversity of epifaunal diversity may well be simply because those corallines are the available habitat within the sampled part of the coastline. Lastly, macroinvertebrate trait distribution on the South African coastline confirms that the habitat, particularly the biotic filter (in this case chl-a) provides a templet upon which evolution forges species traits. However, since temperature is a proxy for nutrient availability (cold upwelling brings nutrients), then temperature drives chlorophyll-a. Subsequently this means the abiotic component indirectly drives trait distribution by influencing the biotic environment (chl-a). For epifauna species, also, the coralline diversity and composition can also be regarded as a biotic filter influencing the epifaunal abundances and composition across different bioregions. Moreover, since temperature is regarded as a conservative trait in seaweeds, temperature tolerance defines the biogeographical boundaries of seaweeds, therefore temperature may be indirectly affecting epifauna abundances through coralline species diversity and biomass. In summary, considering the deterministic processes governing ecosystem functioning and community assemblage, the mass ratio and limiting similarity hypotheses showed complementary effects. Different bioregions provided variable support for these two hypotheses, but overall, the mass ratio hypothesis (weighted by species biomass) received stronger support and may be more meaningful to the interpretation of ecosystem functioning and persistence within rocky shore systems. Lastly, although, the SWO showed some of the characteristics of a subtraction zone based on the relatively low abundance, diversity, and biomass measures. Nonetheless, there was evidence of high functional redundancy across all other four bioregions. This suggests that in the context of development and reproduction traits, the rocky shore ecosystem along the SA coastline may be functionally stable at this stage. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-10-14
Gamification technology in teaching: Exploring how mathematics teachers make use of Kahoot! Gamification to facilitate learning of probability in classrooms
- Authors: Mbete, Ayanda
- Date: 2022-10-14
- Subjects: Gamification , Kahoot! , Mathematics Study and teaching (Elementary) South Africa Eastern Cape , Probabilities , Educational technology , Rural schools South Africa Eastern Cape , Technological Pedagogical Content Knowledge , Cultural-historical activity theory
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405311 , vital:70160
- Description: This study seeks to examine the use of Kahoot! as a gamification technology in practice with Grade six teachers to explore its use in supporting the learning of Probability in Mathematics in rural primary schools. Purposive sampling was adopted wherein nine Grade six mathematics teachers from four rural primary schools in Amathole East district were selected as participants of the study. In addition, to inform this qualitative case study, an interpretive paradigm was adopted. Data was collected using semi-questionnaires, semi-structured interviews, non-participant observations, workshop discussions and reflective journals. The TPACK by Mishra & Koehler (2009) and Vygotsky’s (1978) socio-cultural theory were employed as the lenses through which all the proceedings of the study were based. The key findings indicate that integrating Kahoot! gamification technology, in the ‘Probability’ lesson, has positive consequences such as bringing fun into the classroom, enhancing learner participation, prompt feedback and offering a learner-driven approach to learning as opposed to the conventional teaching strategies. The findings also revealed that enabling and constraining factors are associated with using Kahoot! in teaching: the ICT infrastructure, teachers’ competency levels and the environment in which teaching and learning occurs. This study concluded that the use of Kahoot enhances the learning of probability in rural under-resourced primary schools. This study recommended the integration of Kahoot gamification into the mathematics curriculum. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mbete, Ayanda
- Date: 2022-10-14
- Subjects: Gamification , Kahoot! , Mathematics Study and teaching (Elementary) South Africa Eastern Cape , Probabilities , Educational technology , Rural schools South Africa Eastern Cape , Technological Pedagogical Content Knowledge , Cultural-historical activity theory
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405311 , vital:70160
- Description: This study seeks to examine the use of Kahoot! as a gamification technology in practice with Grade six teachers to explore its use in supporting the learning of Probability in Mathematics in rural primary schools. Purposive sampling was adopted wherein nine Grade six mathematics teachers from four rural primary schools in Amathole East district were selected as participants of the study. In addition, to inform this qualitative case study, an interpretive paradigm was adopted. Data was collected using semi-questionnaires, semi-structured interviews, non-participant observations, workshop discussions and reflective journals. The TPACK by Mishra & Koehler (2009) and Vygotsky’s (1978) socio-cultural theory were employed as the lenses through which all the proceedings of the study were based. The key findings indicate that integrating Kahoot! gamification technology, in the ‘Probability’ lesson, has positive consequences such as bringing fun into the classroom, enhancing learner participation, prompt feedback and offering a learner-driven approach to learning as opposed to the conventional teaching strategies. The findings also revealed that enabling and constraining factors are associated with using Kahoot! in teaching: the ICT infrastructure, teachers’ competency levels and the environment in which teaching and learning occurs. This study concluded that the use of Kahoot enhances the learning of probability in rural under-resourced primary schools. This study recommended the integration of Kahoot gamification into the mathematics curriculum. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
Genetic analysis and field application of a UV-tolerant strain of CrleGV for improved control of Thaumatotibia leucotreta
- Authors: Bennett, Tahnee Tashia
- Date: 2022-10-14
- Subjects: Cryptophlebia leucotreta Biological control , Pests Integrated control , Biological pest control agents , Ultraviolet radiation , Oligonucleotides
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362741 , vital:65358
- Description: Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), also known as false codling moth (FCM), is indigenous to sub-Saharan Africa. Thaumatotibia leucotreta has been controlled through an integrated pest management (IPM) programme, which includes chemical control, sterile insect technique (SIT), cultural and biological control. As part of the biological control, a key component is the use of Cryptophlebia leucotreta granulovirus (CrleGV-SA). Currently, CryptogranTM, a commercial formulation of CrleGV, is the preferred product to use in South Africa for the control of T. leucotreta. The registration of the biopesticide Cryptogran (River bioscience, South Africa) was established after conducting extensive field trials with CrleGV-SA. One of the major factors affecting the baculovirus efficacy in the field is UV irradiation. A UV-tolerant Cryptophlebia leucotreta granulovirus (CrleGV-SA-C5) isolate was isolated after consecutive cycles of UV exposure. This UV-tolerant isolate is genetically distinct from the CrleGV-SA isolate. The CrleGV-SA-C5 isolate has the potential as a biological control agent. The control of T. leucotreta in South Africa could be improved by the development of novel isolates into new biopesticide formulations. To date, there has not been any field trials conducted on the CrleGV-SA-C5 isolate. Therefore, it is important to determine the biological and genetic stability of this isolate and to conduct field trials with CrleGV-SA- C5 to test the efficacy of the isolate before possible production into a biopesticide. A de novo assembly was conducted to reassemble the genome of CrleGV-SA-C5 which was followed by a sequence comparison with the CrleGV-SA genome. The identification of SNPs, led to the design of oligonucleotides flanking the regions where the SNPs were detected. Polymerase chain reaction amplification of the target regions was conducted using the oligonucleotides. After sequence comparison, seven SNPs were detected and PCR amplification was successful using the three oligonucleotides, Pif-2, HypoP and Lef-8/HP. To differentiate between CrleGV-SA-C5 and CrleGV-SA genomes and confirm the presence of the SNPs, two methods of screening were conducted. The first was the construction of six plasmids, the plasmids contained the targeted pif-2, HypoP, and the Lef-8/HP insert regions from both the CrleGV-SA-C5 and CrleGV-SA genome region where the SNPs were identified, followed by sequencing. The Five recombinant plasmids, pC5_Pif-2, pSA_Pif-2, pC5_HypoP, pSA_HypoP, and pC5_Lef-8/HP were successfully sequenced. No amplicon was obtained for one of the plasmids used as template (pSA_Lef-8/HP) and therefore the PCR product used for cloning was sequenced instead. Sequence alignment confirmed the presence of four of the five targeted SNPs in the genome of the CrleGV-SA-C5 isolate. However, of these only one SNP (UV_7) rendered a suitable marker for the differentiation between the CrleGV-SA-C5 and CrleGV-SA isolates as the SNPs, UV_2, UV_3 and UV_5, were also present in the CrleGV- SA sequences. The second screening method was a quantitative polymerase chain reaction (qPCR) melt curve analysis to differentiate between the CrleGV-SA-C5 and CrleGV-SA isolates. qPCR melt curve analysis was done using the CrleGV-SA-C5 and CrleGV-SA HypoP PCR products. This technique was unable to differentiate between the CrleGV-SA-C5 and CrleGV-SA isolates. However, this may be as a result of sequence data confirming that SNP UV_5 originally identified in the CrleGV-SA-C5 HypoP region was identical to the SNP at the same position in the CrleGV-SA HypoP region. Following the differentiation of the CrleGV-SA-C5 and CrleGV-SA isolates through two screening methods, the genetic integrity of the CrleGV-SA-C5 isolate after two virus bulk-ups was determined by PCR amplification of the target regions in the bulk-up virus followed by sequencing. Prior to virus bulk-up, surface dose bioassays were conducted on 4th instar larvae and LC50 and LC90 values of 4.01 x 106 OBs/ml and 8.75 x 109 OBs/ml respectively were obtained. The CrleGV-SA-C5 isolate was then bulked up in fourth instar T. leucotreta larvae using the LC90 value that was determined. Sequencing of the target regions from the CrleGV- SA-C5_BU2 (bulk-up 2) was conducted. Sequencing results confirmed the presence of the target SNPs in the CrleGV-SA-C5_BU2 genome. The UV-tolerance of the CrleGV-SA-C5 isolate in comparison to the CrleGV-SA isolate was evaluated by detached fruit bioassays under natural UV irradiation. Two detached fruit bioassays were set-up, a UV exposure and a non-UV exposure bioassay set-up. Three treatments were used for each bioassay set-up which were the viruses CrleGV-SA-C5 and CrleGV-SA and a ddH2O control. Statistical analysis indicated that there was no significant difference between the virus treatments in both the UV exposed detached fruit bioassay and the non-UV exposed detached fruit bioassay. This study is the second study to report on the de novo assembly of the CrleGV-SA-C5 and sequence comparison with the CrleGV-SA genome, and the first to report on the UV-tolerance of the CrleGV-SA-C5 isolate by detached fruit bioassays. Future work could involve further evaluation of intraspecific genetic variability in the CrleGV-SA-C5 isolate and to identify any additional SNPs present within the genome that can be used as suitable markers for differentiation between the CrleGV-SA-C5 and CrleGV-SA isolates. It was recognised that it is required to conduct further detached fruit bioassays and field trials, but with improved protocols, for the efficacy and UV-tolerance of the CrleGV-SA-C5 isolate to be conclusively determined. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Bennett, Tahnee Tashia
- Date: 2022-10-14
- Subjects: Cryptophlebia leucotreta Biological control , Pests Integrated control , Biological pest control agents , Ultraviolet radiation , Oligonucleotides
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362741 , vital:65358
- Description: Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), also known as false codling moth (FCM), is indigenous to sub-Saharan Africa. Thaumatotibia leucotreta has been controlled through an integrated pest management (IPM) programme, which includes chemical control, sterile insect technique (SIT), cultural and biological control. As part of the biological control, a key component is the use of Cryptophlebia leucotreta granulovirus (CrleGV-SA). Currently, CryptogranTM, a commercial formulation of CrleGV, is the preferred product to use in South Africa for the control of T. leucotreta. The registration of the biopesticide Cryptogran (River bioscience, South Africa) was established after conducting extensive field trials with CrleGV-SA. One of the major factors affecting the baculovirus efficacy in the field is UV irradiation. A UV-tolerant Cryptophlebia leucotreta granulovirus (CrleGV-SA-C5) isolate was isolated after consecutive cycles of UV exposure. This UV-tolerant isolate is genetically distinct from the CrleGV-SA isolate. The CrleGV-SA-C5 isolate has the potential as a biological control agent. The control of T. leucotreta in South Africa could be improved by the development of novel isolates into new biopesticide formulations. To date, there has not been any field trials conducted on the CrleGV-SA-C5 isolate. Therefore, it is important to determine the biological and genetic stability of this isolate and to conduct field trials with CrleGV-SA- C5 to test the efficacy of the isolate before possible production into a biopesticide. A de novo assembly was conducted to reassemble the genome of CrleGV-SA-C5 which was followed by a sequence comparison with the CrleGV-SA genome. The identification of SNPs, led to the design of oligonucleotides flanking the regions where the SNPs were detected. Polymerase chain reaction amplification of the target regions was conducted using the oligonucleotides. After sequence comparison, seven SNPs were detected and PCR amplification was successful using the three oligonucleotides, Pif-2, HypoP and Lef-8/HP. To differentiate between CrleGV-SA-C5 and CrleGV-SA genomes and confirm the presence of the SNPs, two methods of screening were conducted. The first was the construction of six plasmids, the plasmids contained the targeted pif-2, HypoP, and the Lef-8/HP insert regions from both the CrleGV-SA-C5 and CrleGV-SA genome region where the SNPs were identified, followed by sequencing. The Five recombinant plasmids, pC5_Pif-2, pSA_Pif-2, pC5_HypoP, pSA_HypoP, and pC5_Lef-8/HP were successfully sequenced. No amplicon was obtained for one of the plasmids used as template (pSA_Lef-8/HP) and therefore the PCR product used for cloning was sequenced instead. Sequence alignment confirmed the presence of four of the five targeted SNPs in the genome of the CrleGV-SA-C5 isolate. However, of these only one SNP (UV_7) rendered a suitable marker for the differentiation between the CrleGV-SA-C5 and CrleGV-SA isolates as the SNPs, UV_2, UV_3 and UV_5, were also present in the CrleGV- SA sequences. The second screening method was a quantitative polymerase chain reaction (qPCR) melt curve analysis to differentiate between the CrleGV-SA-C5 and CrleGV-SA isolates. qPCR melt curve analysis was done using the CrleGV-SA-C5 and CrleGV-SA HypoP PCR products. This technique was unable to differentiate between the CrleGV-SA-C5 and CrleGV-SA isolates. However, this may be as a result of sequence data confirming that SNP UV_5 originally identified in the CrleGV-SA-C5 HypoP region was identical to the SNP at the same position in the CrleGV-SA HypoP region. Following the differentiation of the CrleGV-SA-C5 and CrleGV-SA isolates through two screening methods, the genetic integrity of the CrleGV-SA-C5 isolate after two virus bulk-ups was determined by PCR amplification of the target regions in the bulk-up virus followed by sequencing. Prior to virus bulk-up, surface dose bioassays were conducted on 4th instar larvae and LC50 and LC90 values of 4.01 x 106 OBs/ml and 8.75 x 109 OBs/ml respectively were obtained. The CrleGV-SA-C5 isolate was then bulked up in fourth instar T. leucotreta larvae using the LC90 value that was determined. Sequencing of the target regions from the CrleGV- SA-C5_BU2 (bulk-up 2) was conducted. Sequencing results confirmed the presence of the target SNPs in the CrleGV-SA-C5_BU2 genome. The UV-tolerance of the CrleGV-SA-C5 isolate in comparison to the CrleGV-SA isolate was evaluated by detached fruit bioassays under natural UV irradiation. Two detached fruit bioassays were set-up, a UV exposure and a non-UV exposure bioassay set-up. Three treatments were used for each bioassay set-up which were the viruses CrleGV-SA-C5 and CrleGV-SA and a ddH2O control. Statistical analysis indicated that there was no significant difference between the virus treatments in both the UV exposed detached fruit bioassay and the non-UV exposed detached fruit bioassay. This study is the second study to report on the de novo assembly of the CrleGV-SA-C5 and sequence comparison with the CrleGV-SA genome, and the first to report on the UV-tolerance of the CrleGV-SA-C5 isolate by detached fruit bioassays. Future work could involve further evaluation of intraspecific genetic variability in the CrleGV-SA-C5 isolate and to identify any additional SNPs present within the genome that can be used as suitable markers for differentiation between the CrleGV-SA-C5 and CrleGV-SA isolates. It was recognised that it is required to conduct further detached fruit bioassays and field trials, but with improved protocols, for the efficacy and UV-tolerance of the CrleGV-SA-C5 isolate to be conclusively determined. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-10-14
Global climate justice: the case of climate migrants
- Van Heerden, Samantha Jane Ashburner
- Authors: Van Heerden, Samantha Jane Ashburner
- Date: 2022-10-14
- Subjects: Climate justice , Environmental refugees , Climatic changes Social aspects , Applied ethics , Political science Philosophy , Refugees , Global justice , Relocation (Housing) Environmental aspects
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406749 , vital:70304
- Description: Climate change is predicted to displace thousands of people across the globe. Due to their geographical location and limited resources available for adaptation, this will particularly impact those in developing states, who might have to flee from the growing frequency and severity of rising sea levels, drought and desertification, and acute natural disasters such as floods, wildfires, and hurricanes. This is likely to have pervasive effects on the moral interests of those affected, threatening loss of life, the deterioration of livelihoods, and for small island states even complete or substantial loss of state territory. In this thesis I will argue that we should conceive of this situation as a problem of global justice. Though some argue that questions of justice only arise within the state, I will argue that global economic and political institutions have contributed to the plight of climate migrants, and that following from Darrel Moellendorf’s theory of associational justice, this enduring impact results in an association and duties of justice that transcend state borders. To respect the dignity of climate migrants, such an unjust association needs to be rectified by establishing ethical principles that could be reasonably endorsed by everyone affected. Drawing from Gillian Brock, I will argue that the best way to rectify the situation is through establishing a principle of distributive justice which focuses on ‘agency needs’: needs whose fulfilment is necessary for human agency. Using this framework, I then provide some recommendations of what is owed to climate migrants to achieve justice for them. I also consider how these duties of justice should be distributed, first critiquing a dominant approach that attributes duties primarily to polluters. In the end, I recommend that duties should be dispersed between all those who support the global institutions responsible, those who have been high polluters since 1990, and the most affluent in the world. As the effects of climate change become increasingly pronounced within the next fifty years, establishing what is owed to those displaced is of utmost importance, and I hope this thesis shows how normative philosophy can help us think through these urgent questions. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Van Heerden, Samantha Jane Ashburner
- Date: 2022-10-14
- Subjects: Climate justice , Environmental refugees , Climatic changes Social aspects , Applied ethics , Political science Philosophy , Refugees , Global justice , Relocation (Housing) Environmental aspects
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406749 , vital:70304
- Description: Climate change is predicted to displace thousands of people across the globe. Due to their geographical location and limited resources available for adaptation, this will particularly impact those in developing states, who might have to flee from the growing frequency and severity of rising sea levels, drought and desertification, and acute natural disasters such as floods, wildfires, and hurricanes. This is likely to have pervasive effects on the moral interests of those affected, threatening loss of life, the deterioration of livelihoods, and for small island states even complete or substantial loss of state territory. In this thesis I will argue that we should conceive of this situation as a problem of global justice. Though some argue that questions of justice only arise within the state, I will argue that global economic and political institutions have contributed to the plight of climate migrants, and that following from Darrel Moellendorf’s theory of associational justice, this enduring impact results in an association and duties of justice that transcend state borders. To respect the dignity of climate migrants, such an unjust association needs to be rectified by establishing ethical principles that could be reasonably endorsed by everyone affected. Drawing from Gillian Brock, I will argue that the best way to rectify the situation is through establishing a principle of distributive justice which focuses on ‘agency needs’: needs whose fulfilment is necessary for human agency. Using this framework, I then provide some recommendations of what is owed to climate migrants to achieve justice for them. I also consider how these duties of justice should be distributed, first critiquing a dominant approach that attributes duties primarily to polluters. In the end, I recommend that duties should be dispersed between all those who support the global institutions responsible, those who have been high polluters since 1990, and the most affluent in the world. As the effects of climate change become increasingly pronounced within the next fifty years, establishing what is owed to those displaced is of utmost importance, and I hope this thesis shows how normative philosophy can help us think through these urgent questions. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2022
- Full Text:
- Date Issued: 2022-10-14
High road or common neoliberal trajectory? Collective bargaining, wage share, and varieties of capitalism
- Mpuku, Mutale Natasha Muchule
- Authors: Mpuku, Mutale Natasha Muchule
- Date: 2022-10-14
- Subjects: Collective bargaining , Globalization , Labor union members , Wages Statistics , Income distribution , Economic development , Neoliberalism , Capitalism
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/357611 , vital:64760
- Description: Wage shares have been falling since the 1980s across developing and developed countries. There has also been a downward trend with labour market institutions in these countries, with a few exceptions. This thesis analyzes these trends using firstly an extended literature review and secondly an econometrics analysis of a panel of 36 countries over 39 years. The extended literature review identified two broad competing narratives surrounding this topic: the mainstream and the alternative growth narratives. They both focus on two different growth regimes, the former, posits that growth is profit-led and the latter that growth is wage-led. Both are not ‘zero sum’ processes and seem to offer the same end result (growth and development). However, profit-led growth seems to have two problems. First, at least in the medium run, there is a trade-off between growth and income distribution. And secondly, profit-led growth is contradictory at the global level. Wage-led growth, which offers a ‘high road’ approach, seems far more appealing. Furthermore, several authors, including in South Africa, have claimed that regime-switching (to wage-led growth), is possible, and it seems that labour market institutions may play an important role in facilitating such a switch. However, the empirical literature, especially regarding middle- and low-income countries, is sparse and inconclusive. The panel data analysis provided by this thesis was not conclusive in establishing whether the wage-led, high road path is still viable for countries like South Africa. However, it did not find strong evidence of the contrary. The thesis concluded that there is scope for further research in this field and makes certain suggestions in this regard. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mpuku, Mutale Natasha Muchule
- Date: 2022-10-14
- Subjects: Collective bargaining , Globalization , Labor union members , Wages Statistics , Income distribution , Economic development , Neoliberalism , Capitalism
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/357611 , vital:64760
- Description: Wage shares have been falling since the 1980s across developing and developed countries. There has also been a downward trend with labour market institutions in these countries, with a few exceptions. This thesis analyzes these trends using firstly an extended literature review and secondly an econometrics analysis of a panel of 36 countries over 39 years. The extended literature review identified two broad competing narratives surrounding this topic: the mainstream and the alternative growth narratives. They both focus on two different growth regimes, the former, posits that growth is profit-led and the latter that growth is wage-led. Both are not ‘zero sum’ processes and seem to offer the same end result (growth and development). However, profit-led growth seems to have two problems. First, at least in the medium run, there is a trade-off between growth and income distribution. And secondly, profit-led growth is contradictory at the global level. Wage-led growth, which offers a ‘high road’ approach, seems far more appealing. Furthermore, several authors, including in South Africa, have claimed that regime-switching (to wage-led growth), is possible, and it seems that labour market institutions may play an important role in facilitating such a switch. However, the empirical literature, especially regarding middle- and low-income countries, is sparse and inconclusive. The panel data analysis provided by this thesis was not conclusive in establishing whether the wage-led, high road path is still viable for countries like South Africa. However, it did not find strong evidence of the contrary. The thesis concluded that there is scope for further research in this field and makes certain suggestions in this regard. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
Human Development, the Capability Approach and the Mediating of Sustainable Rural Livelihoods: a case study of women’s empowerment through expansive learning in the Mzimvubu Catchment of the Eastern Cape province, South Africa
- Authors: Conde Aller, Laura
- Date: 2022-10-14
- Subjects: Expansive learning , Social learning , Transformative learning , Capabilities approach (Social sciences) , Women's rights South Africa Mzimvubu River Watershed , Women Economic conditions , Women Social conditions , Sustainable agriculture South Africa Mzimvubu River Watershed
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366236 , vital:65845 , DOI https://doi.org/10.21504/10962/366236
- Description: This study makes a contribution to the field of sustainable agricultural development and women empowerment in rural South Africa by examining the transformations derived from an expansive learning process with a women farmers group in terms of their food production capability expansion and empowerment as well as the well-being of their local catchment or landscape where their activity was situated. The study took place in the Lutengele villages along the upper reaches of the lower Mzimvubu Catchment near Port St Johns in the Eastern Cape province of South Africa. Women in southern Africa are significant contributors to household livelihoods through their household food production practices and at the same time they are also one of the primary natural resource users in rural landscapes. In this case study, historical and contemporary ethnographic and situational data revealed disjuncture between existing practice and the fulfilment of women aspirations with regard to food security and social and ecological well-being at large. As a result, central to this study were the concepts of aspirations and capabilities and the role that these played in transformative learning processes via formative intervention research (after Engeström’s concept of expansive learning). Expansive learning emerges from Vygotsky’s early work on mediation of learning through language and culture, which gave raise to Cultural Historical Activity Theory (CHAT). Whereas the Capability Approach (CA) recognises that development interventions or initiatives should focus on “expanding the freedom that deprive people from enjoying their valued beings and doings” (Sen, 1999, p. 3), in other words, what people value or have reason to value. The Capability Approach coupled with CHAT deepens the contextual understanding of the agricultural activity system in light of the engendered power dynamics associated with women having access to productive resources, their culturally expected roles and responsibilities in the institution of their households, their families and the community at large, and most importantly, aspects of gerontocracy defined by their age and status in society. In addition, drawing on the Capability Approach as a lens to view agricultural development, social transformation and empowerment, provided the tools to conceptualise participants’ aspirations, their true value and the capabilities necessary for such aspirations to be realised in a context filled with socio-cultural and political power relations and dynamics faced especially by women. The first phase of the study set out to map the context in which the participants’ small-scale food production activity was situated, their aspirations relevant to sustainable agricultural livelihoods, food security, well-being and lastly, the main factors or contradictions inhibiting participants from attaining the aspired food production goals. During the initial phase of the expansive learning cycle I was able to address the first research question: What tensions and contradictions in aspiration-practice relationships shape household food security in the context of catchment management of the women farmers’ group or river forum in the Lutengele area? Twelve contradictions were identified from the historical and contemporary socio-cultural analysis of the home-based food production practices and agricultural activity in relation to the research participants’ envisaged aspirations, which under further scrutiny were thereafter considered by the participants as critical capabilities to pursue during the collective and transformative learning process in the second phase of the study. In the second phase of the study, a series of second stimuli were introduced in the form of conceptual and material tools and tasks with the aim to move participants along the expansive learning process. This led to the unfolding of the collectively defined Capability Learning Pathways for sustainable food production or expansion of their agricultural capability in the context of sustainability of the local micro-catchment or landscape. Through the various Change Laboratory workshops and supporting mini-cycles in the last stages of the formative interventionist research, participants’ learning and development was supported in a way that not only brought individuals together to co-design relevant solutions, strategies and working groups or committees, but also catalysed and amplified transformative agency and the expansion of food production capability, sustainable land use practices and ultimately empowerment. This answered the second and most important research question: Can, and if so, how can expansive social learning processes shape conversion factors for turning available resources into functionings that enhance household food security capabilities and ecological well-being? The methodology of expansive learning and formative interventionist research design intervention, with supporting mediating tools, has proven a positive intervention in the attainment of capabilities (or functionings) in relation to the participant’s aspired livelihoods and consequently improving their well-being as well as their ability to navigate through the various gendered power dynamics, especially for the young women participating in this study. The study proposes expansive learning as a suitable critical and transformative learning theory and methodology for the mediation of collective deliberations and the pursuit of capability development as charted by the learners’ collective and individual aspirations. This is a learning process that not only pursues the learners’ attainment of material and cognitive changes but also opens up new opportunities and most importantly, the freedom to exercise their agency no matter the circumstances they find themselves in – in other words, the freedom to aspire and to be, do and become what one values as instrumentally and intrinsically critical to live a life that they have reason to value. In sum, the unfolding of the expansive learning process happened at three levels: at the value clarification level in terms of human and non-human relationships and social relationality, the institutional level and the practices level. The study recommends further research on the suitability of expansive learning and Change Laboratories as a Capability Expansion Methodology involving human development and Capability Approach practitioners, particularly those with an interest in informal learning and community-based empowering initiatives. Additionally, further studies are also suggested for examining formative interventionist research as a participatory action research approach for capability development work in education and learning research and in different study fields and contexts. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Conde Aller, Laura
- Date: 2022-10-14
- Subjects: Expansive learning , Social learning , Transformative learning , Capabilities approach (Social sciences) , Women's rights South Africa Mzimvubu River Watershed , Women Economic conditions , Women Social conditions , Sustainable agriculture South Africa Mzimvubu River Watershed
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366236 , vital:65845 , DOI https://doi.org/10.21504/10962/366236
- Description: This study makes a contribution to the field of sustainable agricultural development and women empowerment in rural South Africa by examining the transformations derived from an expansive learning process with a women farmers group in terms of their food production capability expansion and empowerment as well as the well-being of their local catchment or landscape where their activity was situated. The study took place in the Lutengele villages along the upper reaches of the lower Mzimvubu Catchment near Port St Johns in the Eastern Cape province of South Africa. Women in southern Africa are significant contributors to household livelihoods through their household food production practices and at the same time they are also one of the primary natural resource users in rural landscapes. In this case study, historical and contemporary ethnographic and situational data revealed disjuncture between existing practice and the fulfilment of women aspirations with regard to food security and social and ecological well-being at large. As a result, central to this study were the concepts of aspirations and capabilities and the role that these played in transformative learning processes via formative intervention research (after Engeström’s concept of expansive learning). Expansive learning emerges from Vygotsky’s early work on mediation of learning through language and culture, which gave raise to Cultural Historical Activity Theory (CHAT). Whereas the Capability Approach (CA) recognises that development interventions or initiatives should focus on “expanding the freedom that deprive people from enjoying their valued beings and doings” (Sen, 1999, p. 3), in other words, what people value or have reason to value. The Capability Approach coupled with CHAT deepens the contextual understanding of the agricultural activity system in light of the engendered power dynamics associated with women having access to productive resources, their culturally expected roles and responsibilities in the institution of their households, their families and the community at large, and most importantly, aspects of gerontocracy defined by their age and status in society. In addition, drawing on the Capability Approach as a lens to view agricultural development, social transformation and empowerment, provided the tools to conceptualise participants’ aspirations, their true value and the capabilities necessary for such aspirations to be realised in a context filled with socio-cultural and political power relations and dynamics faced especially by women. The first phase of the study set out to map the context in which the participants’ small-scale food production activity was situated, their aspirations relevant to sustainable agricultural livelihoods, food security, well-being and lastly, the main factors or contradictions inhibiting participants from attaining the aspired food production goals. During the initial phase of the expansive learning cycle I was able to address the first research question: What tensions and contradictions in aspiration-practice relationships shape household food security in the context of catchment management of the women farmers’ group or river forum in the Lutengele area? Twelve contradictions were identified from the historical and contemporary socio-cultural analysis of the home-based food production practices and agricultural activity in relation to the research participants’ envisaged aspirations, which under further scrutiny were thereafter considered by the participants as critical capabilities to pursue during the collective and transformative learning process in the second phase of the study. In the second phase of the study, a series of second stimuli were introduced in the form of conceptual and material tools and tasks with the aim to move participants along the expansive learning process. This led to the unfolding of the collectively defined Capability Learning Pathways for sustainable food production or expansion of their agricultural capability in the context of sustainability of the local micro-catchment or landscape. Through the various Change Laboratory workshops and supporting mini-cycles in the last stages of the formative interventionist research, participants’ learning and development was supported in a way that not only brought individuals together to co-design relevant solutions, strategies and working groups or committees, but also catalysed and amplified transformative agency and the expansion of food production capability, sustainable land use practices and ultimately empowerment. This answered the second and most important research question: Can, and if so, how can expansive social learning processes shape conversion factors for turning available resources into functionings that enhance household food security capabilities and ecological well-being? The methodology of expansive learning and formative interventionist research design intervention, with supporting mediating tools, has proven a positive intervention in the attainment of capabilities (or functionings) in relation to the participant’s aspired livelihoods and consequently improving their well-being as well as their ability to navigate through the various gendered power dynamics, especially for the young women participating in this study. The study proposes expansive learning as a suitable critical and transformative learning theory and methodology for the mediation of collective deliberations and the pursuit of capability development as charted by the learners’ collective and individual aspirations. This is a learning process that not only pursues the learners’ attainment of material and cognitive changes but also opens up new opportunities and most importantly, the freedom to exercise their agency no matter the circumstances they find themselves in – in other words, the freedom to aspire and to be, do and become what one values as instrumentally and intrinsically critical to live a life that they have reason to value. In sum, the unfolding of the expansive learning process happened at three levels: at the value clarification level in terms of human and non-human relationships and social relationality, the institutional level and the practices level. The study recommends further research on the suitability of expansive learning and Change Laboratories as a Capability Expansion Methodology involving human development and Capability Approach practitioners, particularly those with an interest in informal learning and community-based empowering initiatives. Additionally, further studies are also suggested for examining formative interventionist research as a participatory action research approach for capability development work in education and learning research and in different study fields and contexts. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
Identification and characterisation of microbial communities and their metabolic potential in meltwater ponds, Western Dronning Mau Land, Antarctica
- Authors: Van Aswegen, Sunet
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365723 , vital:65779
- Description: Thesis embargoed. Expected release date early 2024. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Van Aswegen, Sunet
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365723 , vital:65779
- Description: Thesis embargoed. Expected release date early 2024. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Identification of novel compounds against Plasmodium falciparum Cytochrome bc1 Complex inhibiting the trans-membrane electron transfer pathway: an In Silico study
- Authors: Chebon, Lorna Jemosop
- Date: 2022-10-14
- Subjects: Malaria , Plasmodium falciparum , Molecular dynamics , Antimalarials , Molecules Models , Docking , Cytochromes , Drug resistance , Computer simulation , Drugs Computer-aided design , System analysis
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365666 , vital:65774 , DOI https://doi.org/10.21504/10962/365666
- Description: Malaria continues to be a burden globally with a myriad of challenges deterring eradication efforts. With most antimalarials facing drug resistance, such as atovaquone (ATQ), alternative compounds that can withstand resistance are warranted. The Plasmodium falciparum cytochrome b (PfCytb), a subunit of P. falciparum cytochrome bc1 complex, is a validated drug target. Structurally, cytochrome b, cytochrome c1, and iron sulphur protein (ISP) subunits form the catalytic domain of the protein complex having heme bL, heme bH and iron-sulphur [2FE-2S] cluster cofactors. These cofactos have redox centres to aid in the electron transfer (ET) process. These subunits promote ET mainly through the enzyme’s ubiquinol oxidation (Qo) and ubiquinone reduction (Qi) processes in the catalytic domain. ATQ drug has been used in the prevention and treatment of uncomplicated malaria by targeting PfCytb protein. Once the mitochondrial transmembrane ET pathway is inhibited, it causes a collapse in its membrane potential. Previously reported ATQ drug resistance has been associated with the point mutations Y268C, Y268N and Y268S. Thus, in finding alternatives to the ATQ drug, this research aimed to: i) employ in silico approaches incorporating protein into phospholipid bilayer for the first time to understand the parasites’ resistance mechanism; ii) determine any sequence and structural differences that could be explored in drug design studies; and iii) screen for PfCytb-iron sulphur protein (Cytb-ISP) hit compounds from South African natural compound database (SANCDB) and Medicines for Malaria Venture (MMV) that can withstand the identified mutations. Using computational tools, comparative sequence and structural analyses were performed on the cytochrome b protein, where the ultimate focus was on P. falciparum cytochrome b and its human homolog. Through multiple sequence alignment, motif discovery and phylogeny, differences between P. falciparum and H. sapiens cytochrome b were identified. Protein modelling of both P. falciparum and H. sapiens cytochrome b - iron sulphur protein (PfCytb-ISP and HsCytb-ISP) was performed. Results showed that at the sequence level, there were few amino acid residue differences because the protein is highly conserved. Important to note is the four-residue deletion in Plasmodium spp. absent in the human homolog. Motif analysis discovered five unique motifs in P. falciparum cytochrome b protein which were mapped onto the predicted protein model. These motifs were not in regions of functional importance; hence their function is still unknown. At a structural level, the four-residue deletion was observed to alter the Qo substrate binding pocket as reported in previous studies and confirmed in this study. This deletion resulted in a 0.83 Å structural displacement. Also, there are currently no in silico studies that have performed experiments with P. falciparum cytochrome b protein incorporated into a phospholipid bilayer. Using 350 ns molecular dynamics (MD) simulations of the holo and ATQ-bound systems, the study highlighted the resistance mechanism of the parasite protein where the loss of active site residue-residue interactions was identified, all linked to the three mutations. The identified compromised interactions are likely to destabilise the protein’s function, specifically in the Qo substrate binding site. This showed the possible effect of mutations on ATQ drug activity, where all three mutations were reported to share a similar resistance mechanism. Thereafter, this research work utilised in silico approaches where both Qo active site and interface pocket were targeted by screening the South African natural compounds database (SANCDB) and Medicines for Malaria Venture (MMV) compounds to identify novel selective hits. SANCDB compounds are known for their structural complexity that preserves the potency of the drug molecule. Both SANCDB and MMV compounds have not been explored as inhibitors against the PfCytb drug target. Molecular docking, molecular dynamics (MD) simulations, principal component, and dynamic residue network (DRN; global and local) analyses were utilised to identify and confirm the potential selective inhibitors. Docking results identified compounds that bound selectively onto PfCytb-ISP with a binding energy ≤ -8.7 kcal/mol-1. Further, this work validated a total of eight potential selective compounds to inhibit PfCytb-ISP protein (Qo active site) not only in the wild-type but also in the presence of the point mutations Y268C, Y268N and Y268S. The selective binding of these hit compounds could be linked to the differences reported at sequence/residue level in chapter 3. DRN and residue contact map analyses of the eight compounds in holo and ligand-bound systems revealed reduced residue interactions and decreased protein communication. This suggests that the eight compounds show the possibility of inhibiting the parasite and disrupting important residue-residue interactions. Additionally, 13 selective compounds were identified to bind at the protein’s heterodimer interface, where global and local analysis confirmed their effect on active site residues (distal location) as well as on the communication network. Based on the sequence differences between PfCytb and the human homolog, these findings suggest these selective compounds as potential allosteric modulators of the parasite enzyme, which may serve as possible replacements of the already resistant ATQ drug. Therefore, these findings pave the way for further in vitro studies to establish their anti-plasmodial inhibition levels. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Chebon, Lorna Jemosop
- Date: 2022-10-14
- Subjects: Malaria , Plasmodium falciparum , Molecular dynamics , Antimalarials , Molecules Models , Docking , Cytochromes , Drug resistance , Computer simulation , Drugs Computer-aided design , System analysis
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365666 , vital:65774 , DOI https://doi.org/10.21504/10962/365666
- Description: Malaria continues to be a burden globally with a myriad of challenges deterring eradication efforts. With most antimalarials facing drug resistance, such as atovaquone (ATQ), alternative compounds that can withstand resistance are warranted. The Plasmodium falciparum cytochrome b (PfCytb), a subunit of P. falciparum cytochrome bc1 complex, is a validated drug target. Structurally, cytochrome b, cytochrome c1, and iron sulphur protein (ISP) subunits form the catalytic domain of the protein complex having heme bL, heme bH and iron-sulphur [2FE-2S] cluster cofactors. These cofactos have redox centres to aid in the electron transfer (ET) process. These subunits promote ET mainly through the enzyme’s ubiquinol oxidation (Qo) and ubiquinone reduction (Qi) processes in the catalytic domain. ATQ drug has been used in the prevention and treatment of uncomplicated malaria by targeting PfCytb protein. Once the mitochondrial transmembrane ET pathway is inhibited, it causes a collapse in its membrane potential. Previously reported ATQ drug resistance has been associated with the point mutations Y268C, Y268N and Y268S. Thus, in finding alternatives to the ATQ drug, this research aimed to: i) employ in silico approaches incorporating protein into phospholipid bilayer for the first time to understand the parasites’ resistance mechanism; ii) determine any sequence and structural differences that could be explored in drug design studies; and iii) screen for PfCytb-iron sulphur protein (Cytb-ISP) hit compounds from South African natural compound database (SANCDB) and Medicines for Malaria Venture (MMV) that can withstand the identified mutations. Using computational tools, comparative sequence and structural analyses were performed on the cytochrome b protein, where the ultimate focus was on P. falciparum cytochrome b and its human homolog. Through multiple sequence alignment, motif discovery and phylogeny, differences between P. falciparum and H. sapiens cytochrome b were identified. Protein modelling of both P. falciparum and H. sapiens cytochrome b - iron sulphur protein (PfCytb-ISP and HsCytb-ISP) was performed. Results showed that at the sequence level, there were few amino acid residue differences because the protein is highly conserved. Important to note is the four-residue deletion in Plasmodium spp. absent in the human homolog. Motif analysis discovered five unique motifs in P. falciparum cytochrome b protein which were mapped onto the predicted protein model. These motifs were not in regions of functional importance; hence their function is still unknown. At a structural level, the four-residue deletion was observed to alter the Qo substrate binding pocket as reported in previous studies and confirmed in this study. This deletion resulted in a 0.83 Å structural displacement. Also, there are currently no in silico studies that have performed experiments with P. falciparum cytochrome b protein incorporated into a phospholipid bilayer. Using 350 ns molecular dynamics (MD) simulations of the holo and ATQ-bound systems, the study highlighted the resistance mechanism of the parasite protein where the loss of active site residue-residue interactions was identified, all linked to the three mutations. The identified compromised interactions are likely to destabilise the protein’s function, specifically in the Qo substrate binding site. This showed the possible effect of mutations on ATQ drug activity, where all three mutations were reported to share a similar resistance mechanism. Thereafter, this research work utilised in silico approaches where both Qo active site and interface pocket were targeted by screening the South African natural compounds database (SANCDB) and Medicines for Malaria Venture (MMV) compounds to identify novel selective hits. SANCDB compounds are known for their structural complexity that preserves the potency of the drug molecule. Both SANCDB and MMV compounds have not been explored as inhibitors against the PfCytb drug target. Molecular docking, molecular dynamics (MD) simulations, principal component, and dynamic residue network (DRN; global and local) analyses were utilised to identify and confirm the potential selective inhibitors. Docking results identified compounds that bound selectively onto PfCytb-ISP with a binding energy ≤ -8.7 kcal/mol-1. Further, this work validated a total of eight potential selective compounds to inhibit PfCytb-ISP protein (Qo active site) not only in the wild-type but also in the presence of the point mutations Y268C, Y268N and Y268S. The selective binding of these hit compounds could be linked to the differences reported at sequence/residue level in chapter 3. DRN and residue contact map analyses of the eight compounds in holo and ligand-bound systems revealed reduced residue interactions and decreased protein communication. This suggests that the eight compounds show the possibility of inhibiting the parasite and disrupting important residue-residue interactions. Additionally, 13 selective compounds were identified to bind at the protein’s heterodimer interface, where global and local analysis confirmed their effect on active site residues (distal location) as well as on the communication network. Based on the sequence differences between PfCytb and the human homolog, these findings suggest these selective compounds as potential allosteric modulators of the parasite enzyme, which may serve as possible replacements of the already resistant ATQ drug. Therefore, these findings pave the way for further in vitro studies to establish their anti-plasmodial inhibition levels. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Identification of selective novel hits against Mycobacterium tuberculosis KasA potential allosteric sites using bioinformatics approaches
- Authors: Hare, Fadzayi Faith
- Date: 2022-10-14
- Subjects: Tuberculosis , Docking , Molecules Models , Virtual screening , Multidrug-resistant tuberculosis , Fatty acids Synthesis , Drugs Design
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362842 , vital:65367
- Description: Tuberculosis (TB) is a global health threat that has led to approximately 1.5 million deaths annually. According to the World Health Organization (WHO), TB is among the top ten deadly diseases and is the leading cause of death due to a single infectious agent. The main challenge in the effective treatment and control of TB is the ongoing emergence of resistant strains of Mycobacterium tuberculosis (Mtb) which lead to multi-drug resistant (MDR) and extensive-drug resistant (XDR) TB. Hence, the identification and characterization of novel drug targets and drugs that modulate the activity of the pathogen are an urgent priority. The current situation even necessitates the reengineering or repurposing of drugs in order to achieve effective control. The β-ketoacyl-acyl carrier protein synthase I (KasA) of Mycobacterium tuberculosis is an essential enzyme in the mycobacterial fatty acid synthesis (FAS-II) pathway and is believed to be a promising target for drug discovery in TB. It is one of the five main proteins of the FAS-II pathway and catalyzes a key condensation reaction in the synthesis of meromycolate chains, the precursors of mycolic acids involved in cell wall formation. Although this protein has been extensively studied, little research has been devoted to the allosteric inhibition of potential drug compounds. The main aim of this research was to identify the allosteric sites on the protein that could be involved in the inhibition of substrate binding activities and novel drug compounds that bind to these sites by use of in-silico approaches. The bioinformatics approaches used in this study were divided into four main objectives namely identification of KasA homolog sequences, sequence analysis and protein characterization, allosteric site search and lastly virtual screening of DrugBank compounds via molecular docking. Fifteen homolog sequences were identified from the BLASTP analysis and were derived from bacteria, fungi and mammals. In order to discover important residues and regions within the KasA proteins, sequence alignment, motif analysis and phylogenetic studies were performed using Mtb KasA as a reference. Sequence alignment revealed conserved residues in all KasA proteins that have functional importance such as the catalytic triad residues (Cys171, His311 and His345). Motif analysis identified 18 highly conserved motifs within the KasA proteins with structural and functional roles. In addition, motifs unique to the Mtb KasA protein were also identified and explored for inhibitor drug design purposes. Phylogenetic analysis of the homolog sequences showed a distinct clustering of prokaryotes and eukaryotes. A distinctive clustering was also observed for species belonging to the same genus. Since the mechanism of action of most drugs involves the active site, allosteric site search was conducted on Mtb KasA and the human homolog protein using a combination of pocket detection algorithms with the aim of identifying sites that could be utilized in allosteric modulator drug discovery. This was followed by the virtual screening of 2089 FDA approved DrugBank compounds against the entire protein surfaces of Mtb KasA and Hsmt KasA, performed via molecular docking using AutoDock Vina. Screening of the compounds was based on the binding energies, with more focus on identifying ligands that bound exclusively to the acyl-binding tunnel of Mtb KasA. This reduced the data set to 27 promising drug compounds with a relatively high binding affinity for Mtb KasA, however, further experiments need to be performed to validate this result. Among these compounds were DB08889, DB06755, DB09270, DB11226, DB00392, DB12278, DB08936, DB00781, DB13720 and DB00392, which displayed relatively low binding energies for Mtb KasA when compared to the human homolog protein. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Hare, Fadzayi Faith
- Date: 2022-10-14
- Subjects: Tuberculosis , Docking , Molecules Models , Virtual screening , Multidrug-resistant tuberculosis , Fatty acids Synthesis , Drugs Design
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362842 , vital:65367
- Description: Tuberculosis (TB) is a global health threat that has led to approximately 1.5 million deaths annually. According to the World Health Organization (WHO), TB is among the top ten deadly diseases and is the leading cause of death due to a single infectious agent. The main challenge in the effective treatment and control of TB is the ongoing emergence of resistant strains of Mycobacterium tuberculosis (Mtb) which lead to multi-drug resistant (MDR) and extensive-drug resistant (XDR) TB. Hence, the identification and characterization of novel drug targets and drugs that modulate the activity of the pathogen are an urgent priority. The current situation even necessitates the reengineering or repurposing of drugs in order to achieve effective control. The β-ketoacyl-acyl carrier protein synthase I (KasA) of Mycobacterium tuberculosis is an essential enzyme in the mycobacterial fatty acid synthesis (FAS-II) pathway and is believed to be a promising target for drug discovery in TB. It is one of the five main proteins of the FAS-II pathway and catalyzes a key condensation reaction in the synthesis of meromycolate chains, the precursors of mycolic acids involved in cell wall formation. Although this protein has been extensively studied, little research has been devoted to the allosteric inhibition of potential drug compounds. The main aim of this research was to identify the allosteric sites on the protein that could be involved in the inhibition of substrate binding activities and novel drug compounds that bind to these sites by use of in-silico approaches. The bioinformatics approaches used in this study were divided into four main objectives namely identification of KasA homolog sequences, sequence analysis and protein characterization, allosteric site search and lastly virtual screening of DrugBank compounds via molecular docking. Fifteen homolog sequences were identified from the BLASTP analysis and were derived from bacteria, fungi and mammals. In order to discover important residues and regions within the KasA proteins, sequence alignment, motif analysis and phylogenetic studies were performed using Mtb KasA as a reference. Sequence alignment revealed conserved residues in all KasA proteins that have functional importance such as the catalytic triad residues (Cys171, His311 and His345). Motif analysis identified 18 highly conserved motifs within the KasA proteins with structural and functional roles. In addition, motifs unique to the Mtb KasA protein were also identified and explored for inhibitor drug design purposes. Phylogenetic analysis of the homolog sequences showed a distinct clustering of prokaryotes and eukaryotes. A distinctive clustering was also observed for species belonging to the same genus. Since the mechanism of action of most drugs involves the active site, allosteric site search was conducted on Mtb KasA and the human homolog protein using a combination of pocket detection algorithms with the aim of identifying sites that could be utilized in allosteric modulator drug discovery. This was followed by the virtual screening of 2089 FDA approved DrugBank compounds against the entire protein surfaces of Mtb KasA and Hsmt KasA, performed via molecular docking using AutoDock Vina. Screening of the compounds was based on the binding energies, with more focus on identifying ligands that bound exclusively to the acyl-binding tunnel of Mtb KasA. This reduced the data set to 27 promising drug compounds with a relatively high binding affinity for Mtb KasA, however, further experiments need to be performed to validate this result. Among these compounds were DB08889, DB06755, DB09270, DB11226, DB00392, DB12278, DB08936, DB00781, DB13720 and DB00392, which displayed relatively low binding energies for Mtb KasA when compared to the human homolog protein. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
Igniting a revolution at point zero? Exploring the barriers to early learning access in South Africa and the possibility of the social economy : a comparative analysis and study of Smartstart
- Authors: McCann, Claire Mary
- Date: 2022-10-14
- Subjects: Early childhood education South Africa , Social economy South Africa , Smart Start , Education and state South Africa , Social democracy , Dual economy South Africa , South Africa Economic conditions 1991-
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/403080 , vital:69920
- Description: Economic theory suggests that the greatest return to education investment is in the earliest years; early learning and childcare may enhance skill accumulation and mothers’ labour market choices. These services may be catalytic, igniting a revolution at point zero that transforms family outcomes and aids development. In South Africa, however, early learning deficits persist. This thesis explores barriers to quality early learning access and the possibility social economy initiatives offer, focusing on social franchises like SmartStart. Document analysis, comparative analysis, and interviews with SmartStart leaders suggest two key barriers. Firstly, where private firms are dominant and ability to pay for services is limited, low-income areas are under-served. For this reason, Polanyi claims that markets should be embedded in institutions. A post-Polanyian approach emphasises the role of social investment states, which focus spending on education and where social protection scaffolds markets, in this regard. The South African state seems to embrace this approach as ECD policy frames early learning as a public good and social investment. However, a second barrier is that an insulated state enables technocratic over democratic embeddedness, with powerful rights-based discourse but poor implementation. In particular, it seems that the state lacks a framework to progressively realise the right to quality early learning. Attempts to enforce high standards are not accompanied by sufficient resources, capacity or collaboration, resulting in sub-standard services and barriers to entry. Even in better resourced contexts (e.g., Basic Education), top-down, technocratic models (re)produce failing systems, where those with means exit in favour of market alternatives. An exploration of other developing countries suggests that this failure, with variations, prevails, but also that possibility exists. In these contexts, states seem more coordinated and responsive when partnering with civil society. In South Africa, the SmartStart model is based on partnership. SmartStart frames itself as a delivery platform, building relationships with local NGOs to simultaneously scale and deepen early learning. Partnerships with communities are crucial, to build demand in a sector whose association with social reproduction means that its economic significance may be overlooked. In addition, SmartStart puts forward a child-centred approach based on a prefigurative vision but also responsive to the realities of under-resourced contexts, aiming to progressively realise rights. Though with some limitations, SmartStart’s least-cost innovation for scale provides lessons for the state. As the state’s ECD mandate shifts to Basic Education, these findings serve to inform a more effective implementation model, leveraging resources that already exist. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: McCann, Claire Mary
- Date: 2022-10-14
- Subjects: Early childhood education South Africa , Social economy South Africa , Smart Start , Education and state South Africa , Social democracy , Dual economy South Africa , South Africa Economic conditions 1991-
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/403080 , vital:69920
- Description: Economic theory suggests that the greatest return to education investment is in the earliest years; early learning and childcare may enhance skill accumulation and mothers’ labour market choices. These services may be catalytic, igniting a revolution at point zero that transforms family outcomes and aids development. In South Africa, however, early learning deficits persist. This thesis explores barriers to quality early learning access and the possibility social economy initiatives offer, focusing on social franchises like SmartStart. Document analysis, comparative analysis, and interviews with SmartStart leaders suggest two key barriers. Firstly, where private firms are dominant and ability to pay for services is limited, low-income areas are under-served. For this reason, Polanyi claims that markets should be embedded in institutions. A post-Polanyian approach emphasises the role of social investment states, which focus spending on education and where social protection scaffolds markets, in this regard. The South African state seems to embrace this approach as ECD policy frames early learning as a public good and social investment. However, a second barrier is that an insulated state enables technocratic over democratic embeddedness, with powerful rights-based discourse but poor implementation. In particular, it seems that the state lacks a framework to progressively realise the right to quality early learning. Attempts to enforce high standards are not accompanied by sufficient resources, capacity or collaboration, resulting in sub-standard services and barriers to entry. Even in better resourced contexts (e.g., Basic Education), top-down, technocratic models (re)produce failing systems, where those with means exit in favour of market alternatives. An exploration of other developing countries suggests that this failure, with variations, prevails, but also that possibility exists. In these contexts, states seem more coordinated and responsive when partnering with civil society. In South Africa, the SmartStart model is based on partnership. SmartStart frames itself as a delivery platform, building relationships with local NGOs to simultaneously scale and deepen early learning. Partnerships with communities are crucial, to build demand in a sector whose association with social reproduction means that its economic significance may be overlooked. In addition, SmartStart puts forward a child-centred approach based on a prefigurative vision but also responsive to the realities of under-resourced contexts, aiming to progressively realise rights. Though with some limitations, SmartStart’s least-cost innovation for scale provides lessons for the state. As the state’s ECD mandate shifts to Basic Education, these findings serve to inform a more effective implementation model, leveraging resources that already exist. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-10-14