Continuing teacher professional development in the Environment Sector: A case study of Fundisa for Change continuing teacher professional development programme
- Authors: Nkhahle, Lebona Jerome
- Date: 2021-10-29
- Subjects: Environmental education South Africa , Pedagogical content knowledge , Teachers In-service training South Africa , Curriculum-based assessment South Africa , Fundisa for Change , Practice Architectures
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192724 , vital:45254 , 10.21504/10962/192724
- Description: The importance of teachers being engaged in professional development initiatives is widely acknowledged in the literature and in most cases these initiatives are largely focused on addressing teachers’ lack of subject content knowledge. The problem of teachers having inadequate environmental knowledge is common in South Africa due to the fact that much of the environmental content knowledge in the curriculum is new, and environmental education itself is a new field. This is an area of interest in South Africa as a third iteration of the post-apartheid curriculum, the Curriculum and Assessment Policy Statement (CAPS) has recently been introduced into schools and many subjects have environmental learning content. Inadequate subject content knowledge influences teachers’ abilities to choose appropriate teaching and assessment methods and this might negatively affect the process of teaching and learning. Knowledgeable teachers are needed to help learners understand the current issues affecting citizens, and in particular, environmental issues, which form the focus of this study. The main research questions addressed are: 1. What are the teachers’ experiences of the Fundisa for Change continuing teacher professional development programme in relation to environment and sustainability content knowledge? 2. How does the Fundisa for Change continuing teacher professional development programme influence teachers’ practice? 3. What practices of the Fundisa for Change teacher professional development programme are characteristic of effective continuing teacher professional development initiatives? 4. How are (if at all) the practices of teacher training, teacher learning, teaching and assessment of Biodiversity content in CAPS living practices? This work was conducted as a qualitative case study and it was carried out in the provinces of Gauteng, Eastern Cape and Mpumalanga in South Africa. It included four teachers from the Eastern Cape and five from Mpumalanga. Seven teacher trainers also participated, two of which were based in Gauteng and the rest in the Eastern Cape. Data were generated through interviews and document analysis, and included analysis of teacher portfolios showing evidence of classroom practice. The study explored teachers’ experiences of an environmental education training programme called ‘Fundisa for Change’, which has been set up as a national partnership initiative to strengthen teachers’ environmental knowledge and teaching skills in order to address the above-mentioned problem. It focused on training teachers in the Life Sciences, particularly on new content knowledge on Biodiversity, and on teaching and assessment skills. It also looked into how the training influenced teaching practice. The study worked with practice theory, in particular Kemmis and Grootenboer’s (2008) theory of practice architectures, to look at the sayings, doings and relatings pertaining to the teaching of Biodiversity, and the enabling and constraining of this practice. The features and the teachers’ experiences of the Fundisa for Change professional development programme have been presented and explained. The study also used the ecologies of practices theory to describe the living nature of practices. The following are the key findings: • The Fundisa for Change programme improved the participating teachers’ Biodiversity content knowledge, teaching and assessment skills. • Practices of the Fundisa for Change teacher professional development programme characteristic of effective continuing teacher professional development initiatives are: duration; active involvement of teachers; providing teachers with subject content knowledge; promoting establishment of professional learning communities; coherence; follow-up; and assessment of teachers. • The conditions that affect the participating teachers’ teaching practice are: the use of language (both scientific and instructional); infrastructure (availability of computer laboratories, science laboratories, extra classrooms and libraries); teaching and learning support materials including laboratory apparatus; class size; and policies. • The Fundisa for Change programme encourages teachers to improvise and use the local environment in their teaching to try to tackle the problem of lack of funds and equipment. • Teaching Biodiversity practice is ‘living’ as it is characterised by the principles of living ecologies. Recommendations based on the findings are: • There is a need for more teacher training by Fundisa for Change and other organisations whose training activities are SACE approved to cater for more teachers. • A more structured plan of action from the Department of Basic Education (DBE) is needed to assist and involve more organisations and stakeholders. • Provision of infrastructure and teaching and learning resource materials to schools by the DBE needs to be accelerated as it is legally binding. • Follow-up should be formally incorporated into Fundisa for Change programme activities. • Formation of professional learning communities is very important to help new teachers as there is no formal induction programme in South Africa. • An induction policy by the DBE needs to be formulated to help establish an induction programme for newly qualified teachers. Recommendations for further research are: • Use of lesson observation for data collection to improve results. • A larger sample could be used to expand the insights gained in this study. • Fundisa for Change practices can be studied at the level of teacher professional development practices. • Other modes of teacher professional development initiatives such as Lesson Study can be tested out to overcome the challenge of teachers not wanting to be observed. • More research can be carried out on the practices of teacher training, teacher learning, student learning and assessment, as practices associated with teaching Biodiversity. The study was important in that it gave an understanding of what makes continuing teacher professional development initiatives effective. The study also looked at teaching Biodiversity through the use of contemporary forms of a practice theory which are the theory of practice architectures and the theory of the ecologies of practices. This provided understandings into how professional development programmes are experienced in practice, and showed that though the teachers were trained and positive benefits accrued, there are factors which enable or constrain their actual teaching Biodiversity practice. The study also showed that practices are interrelated in ecologies of practices. These factors need to be considered in professional development programming. , Thesis (PhD) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Nkhahle, Lebona Jerome
- Date: 2021-10-29
- Subjects: Environmental education South Africa , Pedagogical content knowledge , Teachers In-service training South Africa , Curriculum-based assessment South Africa , Fundisa for Change , Practice Architectures
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192724 , vital:45254 , 10.21504/10962/192724
- Description: The importance of teachers being engaged in professional development initiatives is widely acknowledged in the literature and in most cases these initiatives are largely focused on addressing teachers’ lack of subject content knowledge. The problem of teachers having inadequate environmental knowledge is common in South Africa due to the fact that much of the environmental content knowledge in the curriculum is new, and environmental education itself is a new field. This is an area of interest in South Africa as a third iteration of the post-apartheid curriculum, the Curriculum and Assessment Policy Statement (CAPS) has recently been introduced into schools and many subjects have environmental learning content. Inadequate subject content knowledge influences teachers’ abilities to choose appropriate teaching and assessment methods and this might negatively affect the process of teaching and learning. Knowledgeable teachers are needed to help learners understand the current issues affecting citizens, and in particular, environmental issues, which form the focus of this study. The main research questions addressed are: 1. What are the teachers’ experiences of the Fundisa for Change continuing teacher professional development programme in relation to environment and sustainability content knowledge? 2. How does the Fundisa for Change continuing teacher professional development programme influence teachers’ practice? 3. What practices of the Fundisa for Change teacher professional development programme are characteristic of effective continuing teacher professional development initiatives? 4. How are (if at all) the practices of teacher training, teacher learning, teaching and assessment of Biodiversity content in CAPS living practices? This work was conducted as a qualitative case study and it was carried out in the provinces of Gauteng, Eastern Cape and Mpumalanga in South Africa. It included four teachers from the Eastern Cape and five from Mpumalanga. Seven teacher trainers also participated, two of which were based in Gauteng and the rest in the Eastern Cape. Data were generated through interviews and document analysis, and included analysis of teacher portfolios showing evidence of classroom practice. The study explored teachers’ experiences of an environmental education training programme called ‘Fundisa for Change’, which has been set up as a national partnership initiative to strengthen teachers’ environmental knowledge and teaching skills in order to address the above-mentioned problem. It focused on training teachers in the Life Sciences, particularly on new content knowledge on Biodiversity, and on teaching and assessment skills. It also looked into how the training influenced teaching practice. The study worked with practice theory, in particular Kemmis and Grootenboer’s (2008) theory of practice architectures, to look at the sayings, doings and relatings pertaining to the teaching of Biodiversity, and the enabling and constraining of this practice. The features and the teachers’ experiences of the Fundisa for Change professional development programme have been presented and explained. The study also used the ecologies of practices theory to describe the living nature of practices. The following are the key findings: • The Fundisa for Change programme improved the participating teachers’ Biodiversity content knowledge, teaching and assessment skills. • Practices of the Fundisa for Change teacher professional development programme characteristic of effective continuing teacher professional development initiatives are: duration; active involvement of teachers; providing teachers with subject content knowledge; promoting establishment of professional learning communities; coherence; follow-up; and assessment of teachers. • The conditions that affect the participating teachers’ teaching practice are: the use of language (both scientific and instructional); infrastructure (availability of computer laboratories, science laboratories, extra classrooms and libraries); teaching and learning support materials including laboratory apparatus; class size; and policies. • The Fundisa for Change programme encourages teachers to improvise and use the local environment in their teaching to try to tackle the problem of lack of funds and equipment. • Teaching Biodiversity practice is ‘living’ as it is characterised by the principles of living ecologies. Recommendations based on the findings are: • There is a need for more teacher training by Fundisa for Change and other organisations whose training activities are SACE approved to cater for more teachers. • A more structured plan of action from the Department of Basic Education (DBE) is needed to assist and involve more organisations and stakeholders. • Provision of infrastructure and teaching and learning resource materials to schools by the DBE needs to be accelerated as it is legally binding. • Follow-up should be formally incorporated into Fundisa for Change programme activities. • Formation of professional learning communities is very important to help new teachers as there is no formal induction programme in South Africa. • An induction policy by the DBE needs to be formulated to help establish an induction programme for newly qualified teachers. Recommendations for further research are: • Use of lesson observation for data collection to improve results. • A larger sample could be used to expand the insights gained in this study. • Fundisa for Change practices can be studied at the level of teacher professional development practices. • Other modes of teacher professional development initiatives such as Lesson Study can be tested out to overcome the challenge of teachers not wanting to be observed. • More research can be carried out on the practices of teacher training, teacher learning, student learning and assessment, as practices associated with teaching Biodiversity. The study was important in that it gave an understanding of what makes continuing teacher professional development initiatives effective. The study also looked at teaching Biodiversity through the use of contemporary forms of a practice theory which are the theory of practice architectures and the theory of the ecologies of practices. This provided understandings into how professional development programmes are experienced in practice, and showed that though the teachers were trained and positive benefits accrued, there are factors which enable or constrain their actual teaching Biodiversity practice. The study also showed that practices are interrelated in ecologies of practices. These factors need to be considered in professional development programming. , Thesis (PhD) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
Establishment of human OCT4 as a putative HSP90 client protein: a case for HSP90 chaperoning pluripotency
- Authors: Sterrenberg, Jason Neville
- Date: 2015
- Subjects: Induced pluripotent stem cells , Heat shock proteins , Stem cells , Transcription factors , Molecular chaperones
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/194010 , vital:45415 , 10.21504/10962/194010
- Description: The therapeutic potential of stem cells is already being harnessed in clinical trails. Of even greater therapeutic potential has been the discovery of mechanisms to reprogram differentiated cells into a pluripotent stem cell-like state known as induced pluripotent stem cells (iPSCs). Stem cell nature is governed and maintained by a hierarchy of transcription factors, the apex of which is OCT4. Although much research has elucidated the transcriptional regulation of OCT4, OCT4 regulated gene expression profiles and OCT4 transcriptional activation mechanisms in both stem cell biology and cellular reprogramming to iPSCs, the fundamental biochemistry surrounding the OCT4 transcription factor remains largely unknown. In order to analyze the biochemical relationship between HSP90 and human OCT4 we developed an exogenous active human OCT4 expression model with human OCT4 under transcriptional control of a constitutive promoter. We identified the direct interaction between HSP90 and human OCT4 despite the fact that the proteins predominantly display differential subcellular localizations. We show that HSP90 inhibition resulted in degradation of human OCT4 via the ubiquitin proteasome degradation pathway. As human OCT4 and HSP90 did not interact in the nucleus, we suggest that HSP90 functions in the cytoplasmic stabilization of human OCT4. Our analysis suggests HSP90 inhibition inhibits the transcriptional activity of human OCT4 dimers without affecting monomeric OCT4 activity. Additionally our data suggests that the HSP90 and human OCT4 complex is modulated by phosphorylation events either promoting or abrogating the interaction between HSP90 and human OCT4. Our data suggest that human OCT4 displays the characteristics describing HSP90 client proteins, therefore we identify human OCT4 as a putative HSP90 client protein. The regulation of the transcription factor OCT4 by HSP90 provides fundamental insights into the complex biochemistry of stem cell biology. This may also be suggestive that HSP90 not only regulates stem cell biology by maintaining routine cellular homeostasis but additionally through the direct regulation of pluripotency factors. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2015
- Full Text:
- Date Issued: 2015
- Authors: Sterrenberg, Jason Neville
- Date: 2015
- Subjects: Induced pluripotent stem cells , Heat shock proteins , Stem cells , Transcription factors , Molecular chaperones
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/194010 , vital:45415 , 10.21504/10962/194010
- Description: The therapeutic potential of stem cells is already being harnessed in clinical trails. Of even greater therapeutic potential has been the discovery of mechanisms to reprogram differentiated cells into a pluripotent stem cell-like state known as induced pluripotent stem cells (iPSCs). Stem cell nature is governed and maintained by a hierarchy of transcription factors, the apex of which is OCT4. Although much research has elucidated the transcriptional regulation of OCT4, OCT4 regulated gene expression profiles and OCT4 transcriptional activation mechanisms in both stem cell biology and cellular reprogramming to iPSCs, the fundamental biochemistry surrounding the OCT4 transcription factor remains largely unknown. In order to analyze the biochemical relationship between HSP90 and human OCT4 we developed an exogenous active human OCT4 expression model with human OCT4 under transcriptional control of a constitutive promoter. We identified the direct interaction between HSP90 and human OCT4 despite the fact that the proteins predominantly display differential subcellular localizations. We show that HSP90 inhibition resulted in degradation of human OCT4 via the ubiquitin proteasome degradation pathway. As human OCT4 and HSP90 did not interact in the nucleus, we suggest that HSP90 functions in the cytoplasmic stabilization of human OCT4. Our analysis suggests HSP90 inhibition inhibits the transcriptional activity of human OCT4 dimers without affecting monomeric OCT4 activity. Additionally our data suggests that the HSP90 and human OCT4 complex is modulated by phosphorylation events either promoting or abrogating the interaction between HSP90 and human OCT4. Our data suggest that human OCT4 displays the characteristics describing HSP90 client proteins, therefore we identify human OCT4 as a putative HSP90 client protein. The regulation of the transcription factor OCT4 by HSP90 provides fundamental insights into the complex biochemistry of stem cell biology. This may also be suggestive that HSP90 not only regulates stem cell biology by maintaining routine cellular homeostasis but additionally through the direct regulation of pluripotency factors. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2015
- Full Text:
- Date Issued: 2015
An in-depth investigation of an early literacy intervention in Grade R in the Eastern Cape Province, South Africa
- Authors: Hodgskiss, Jennifer Adelé
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366222 , vital:65844
- Description: Thesis embargoed. Expected release date early 2025. , Thesis (PhD) -- Faculty of Education, Education, 2023
- Full Text:
- Date Issued: 2023-03-29
- Authors: Hodgskiss, Jennifer Adelé
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366222 , vital:65844
- Description: Thesis embargoed. Expected release date early 2025. , Thesis (PhD) -- Faculty of Education, Education, 2023
- Full Text:
- Date Issued: 2023-03-29
Repurposing a polymer precursor scaffold for medicinal application: Synthesis, characterization and biological evaluation of ferrocenyl 1,3-benzoxazine derivatives as potential antiprotozoal and anticancer agents
- Authors: Mbaba, Mziyanda
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/164502 , vital:41124 , DOI 10.21504/10962/164502
- Description: The benzoxazines are a prominent class of heterocyclic compounds that possess a multitude of properties. To this end, benzoxazine derivatives have been used as versatile compounds for various utilities ranging from biological applications to the fabrication of polymers. Particularly, the 1,3-benzoxazine scaffold has featured in several bioactive compounds showing antimalarial, anticancer and antibacterial activities. Traditionally, it has been employed as a substrate in the synthesis of polymers with appealing physical and chemical properties. Due to the increasing interest in the polymer application of 1,3-benzoxazines, research of the 1,3-benzoxazine motif for polymer synthesis has been prioritized over other applications including its medicinal potential. The continuous development of resistance to clinical anticancer and antimalarial drugs has necessitated the need for the search of innovative bioactive compounds as potential alternative medicinal agents. To address this, the field of medicinal chemistry is adapting new approaches to counter resistance by incorporating nonconventional chemical moieties such as organometallic complexes, like ferrocene, into bioactive chemical motifs to serve as novel compounds with medicinal benefits. Incorporation of ferrocene into known bioactive chemical moieties has been shown to impart beneficial biological effects into the resultant compounds, which include the introduction of novel, and sometimes varied, mechanistic modalities and enhanced potency. Presented with the benefits of this strategy, the current work aims to design and evaluate the pharmaceutical capacity of novel derivatives containing 1,3-benzoxazine scaffold (traditionally applied in polymer synthesis) hybridized with the organometallic ferrocene unit as bioactive agents. Using a combination of expedient synthetic procedures such as the Burke three-component Mannich-type condensation, Vilsmeier-Haack formylation and reductive amination, four series of ferrocenyl 1,3-benzoxazine derivatives were synthesized and their structures confirmed by common spectroscopic techniques: nuclear magnetic resonance (NMR), infrared spectroscopy (IR) and high-resolution mass spectrometry (HRMS). The target compounds were evaluated in vitro for potential antimalarial and anticancer activities against strains of the malaria parasite (Plasmodium falciparum 3D7 and Dd2) and the triple-negative breast cancer cell line HCC70. Compounds exhibited higher potency towards the Plasmodium falciparum strains with IC50 values in the low and sub-micromolar range in comparison to the breast cancer cell line against for which mid-molar activities were observed. To gain insight into the possible mode of action of ferrocenyl 1,3-benzoxazines, representative compounds showing most efficacy from each series were assessed for DNA binding affinity by employing UV-Vis and fluorescence DNA titration experiments. The selected compounds were found to interact with the DNA by binding to the minor groove, and these findings were confirmed by in silico ligand docking studies using a B-DNA structure as the receptor. Compound 3.16c (IC50: 0.261 μM [3D7], 0.599 μM [Dd2], 11.0 μM [HCC70]), which emerged as the most promising compound, was found to induce DNA damage in HCC70 cancer cells when investigated for effects of DNA interaction. Additionally, compound 3.16c displayed a higher binding constant (Kb) against DNA isolated from 3D7 Plasmodium falciparum trophozoites (Kb = 1.88×106 M-1) than the mammalian DNA (Kb = 6.33×104 M-1) from calf thymus, thus explaining the preferred selectivity of the compounds for the malaria parasite. Moreover, the investigated compounds demonstrated binding affinity for synthetic hemozoin, β-hematin. Collectively, these data suggest that the compounds possess a dual mode of action for antimalarial activity involving DNA interaction and hemozoin inhibition. , Thesis (PhD) -- Faculty of Science, Chemistry, 2020
- Full Text:
- Date Issued: 2020
- Authors: Mbaba, Mziyanda
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/164502 , vital:41124 , DOI 10.21504/10962/164502
- Description: The benzoxazines are a prominent class of heterocyclic compounds that possess a multitude of properties. To this end, benzoxazine derivatives have been used as versatile compounds for various utilities ranging from biological applications to the fabrication of polymers. Particularly, the 1,3-benzoxazine scaffold has featured in several bioactive compounds showing antimalarial, anticancer and antibacterial activities. Traditionally, it has been employed as a substrate in the synthesis of polymers with appealing physical and chemical properties. Due to the increasing interest in the polymer application of 1,3-benzoxazines, research of the 1,3-benzoxazine motif for polymer synthesis has been prioritized over other applications including its medicinal potential. The continuous development of resistance to clinical anticancer and antimalarial drugs has necessitated the need for the search of innovative bioactive compounds as potential alternative medicinal agents. To address this, the field of medicinal chemistry is adapting new approaches to counter resistance by incorporating nonconventional chemical moieties such as organometallic complexes, like ferrocene, into bioactive chemical motifs to serve as novel compounds with medicinal benefits. Incorporation of ferrocene into known bioactive chemical moieties has been shown to impart beneficial biological effects into the resultant compounds, which include the introduction of novel, and sometimes varied, mechanistic modalities and enhanced potency. Presented with the benefits of this strategy, the current work aims to design and evaluate the pharmaceutical capacity of novel derivatives containing 1,3-benzoxazine scaffold (traditionally applied in polymer synthesis) hybridized with the organometallic ferrocene unit as bioactive agents. Using a combination of expedient synthetic procedures such as the Burke three-component Mannich-type condensation, Vilsmeier-Haack formylation and reductive amination, four series of ferrocenyl 1,3-benzoxazine derivatives were synthesized and their structures confirmed by common spectroscopic techniques: nuclear magnetic resonance (NMR), infrared spectroscopy (IR) and high-resolution mass spectrometry (HRMS). The target compounds were evaluated in vitro for potential antimalarial and anticancer activities against strains of the malaria parasite (Plasmodium falciparum 3D7 and Dd2) and the triple-negative breast cancer cell line HCC70. Compounds exhibited higher potency towards the Plasmodium falciparum strains with IC50 values in the low and sub-micromolar range in comparison to the breast cancer cell line against for which mid-molar activities were observed. To gain insight into the possible mode of action of ferrocenyl 1,3-benzoxazines, representative compounds showing most efficacy from each series were assessed for DNA binding affinity by employing UV-Vis and fluorescence DNA titration experiments. The selected compounds were found to interact with the DNA by binding to the minor groove, and these findings were confirmed by in silico ligand docking studies using a B-DNA structure as the receptor. Compound 3.16c (IC50: 0.261 μM [3D7], 0.599 μM [Dd2], 11.0 μM [HCC70]), which emerged as the most promising compound, was found to induce DNA damage in HCC70 cancer cells when investigated for effects of DNA interaction. Additionally, compound 3.16c displayed a higher binding constant (Kb) against DNA isolated from 3D7 Plasmodium falciparum trophozoites (Kb = 1.88×106 M-1) than the mammalian DNA (Kb = 6.33×104 M-1) from calf thymus, thus explaining the preferred selectivity of the compounds for the malaria parasite. Moreover, the investigated compounds demonstrated binding affinity for synthetic hemozoin, β-hematin. Collectively, these data suggest that the compounds possess a dual mode of action for antimalarial activity involving DNA interaction and hemozoin inhibition. , Thesis (PhD) -- Faculty of Science, Chemistry, 2020
- Full Text:
- Date Issued: 2020
Exploring the value of an educational partnership within a multilingual pre-school setting
- Authors: Maritz, Anneliese
- Date: 2022-10-04
- Subjects: Early childhood education Parent participation South Africa Eastern Cape , Early childhood teachers Training of , Home and school South Africa Eastern Cape , Parent-teacher relationships South Africa Eastern Cape , Communication and education South Africa Eastern Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327111 , vital:61082 , DOI 10.21504/10962/327111
- Description: This modest research project was situated in a multilingual Early Childhood Development (ECD) setting in the Eastern Cape (EC) province of South Africa. In the context of high levels of poverty and unemployment in the EC, issues such as under-funding, the nature of the training of practitioners, translating the importance of learning through play into practice, difficulties dealing with diverse cultural practices and the use of multiple languages, all impact ECD provision. Research has shown that parental involvement and creating parent-school partnerships can assist children to progress at school. The overall objectives of this project were to explore how a team in an ECD centre might communicate more effectively with parents and how early stimulation practices in home and school might benefit the child’s development. The theoretical framework draws upon Vygotsky’s (1978) socio-cultural historical theory, Bernstein’s (1971) elaborated and restricted language codes and Bourdieu’s (1977) concepts of social reproduction. A research project in the Netherlands Thuis in School, used an education partnership approach (Iliás et al., 2019). They developed a manual that was adapted for our local context by drawing from the theories mentioned, and to counter the dominant approaches where parenting programs have often been offered from a deficit, narrow perspective. Action Research guided the interventionist approach to workshop sessions, to enable mutual capacity-building of parents and practitioners. To ensure informed consent, participants’ first languages were used. High risk factors related to photographs and videos of participating parents and minor children were successfully addressed. Pre- and post-interviews and workshop data were analysed using template analysis, within a constructivist paradigm. Findings include vignettes to introduce the contexts and parents' ideas prior to the sessions. Then, sessions are summarised as action cycles, with key participants' responses. Finally, post-session evaluations highlight the topics the parents found most meaningful; and parents’ and practitioner accounts of changes in practices. This research illustrates ways that educational partnership elements can influence practice and policy, to improve home and school environments for the benefit of children. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-10-04
- Authors: Maritz, Anneliese
- Date: 2022-10-04
- Subjects: Early childhood education Parent participation South Africa Eastern Cape , Early childhood teachers Training of , Home and school South Africa Eastern Cape , Parent-teacher relationships South Africa Eastern Cape , Communication and education South Africa Eastern Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327111 , vital:61082 , DOI 10.21504/10962/327111
- Description: This modest research project was situated in a multilingual Early Childhood Development (ECD) setting in the Eastern Cape (EC) province of South Africa. In the context of high levels of poverty and unemployment in the EC, issues such as under-funding, the nature of the training of practitioners, translating the importance of learning through play into practice, difficulties dealing with diverse cultural practices and the use of multiple languages, all impact ECD provision. Research has shown that parental involvement and creating parent-school partnerships can assist children to progress at school. The overall objectives of this project were to explore how a team in an ECD centre might communicate more effectively with parents and how early stimulation practices in home and school might benefit the child’s development. The theoretical framework draws upon Vygotsky’s (1978) socio-cultural historical theory, Bernstein’s (1971) elaborated and restricted language codes and Bourdieu’s (1977) concepts of social reproduction. A research project in the Netherlands Thuis in School, used an education partnership approach (Iliás et al., 2019). They developed a manual that was adapted for our local context by drawing from the theories mentioned, and to counter the dominant approaches where parenting programs have often been offered from a deficit, narrow perspective. Action Research guided the interventionist approach to workshop sessions, to enable mutual capacity-building of parents and practitioners. To ensure informed consent, participants’ first languages were used. High risk factors related to photographs and videos of participating parents and minor children were successfully addressed. Pre- and post-interviews and workshop data were analysed using template analysis, within a constructivist paradigm. Findings include vignettes to introduce the contexts and parents' ideas prior to the sessions. Then, sessions are summarised as action cycles, with key participants' responses. Finally, post-session evaluations highlight the topics the parents found most meaningful; and parents’ and practitioner accounts of changes in practices. This research illustrates ways that educational partnership elements can influence practice and policy, to improve home and school environments for the benefit of children. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-10-04
Neutral Atomic Hydrogen in Gravitationally Lensed Systems
- Authors: Blecher, Tariq Dylan
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192776 , vital:45263
- Description: Thesis (PhD) -- Faculty of Law, Law, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Blecher, Tariq Dylan
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192776 , vital:45263
- Description: Thesis (PhD) -- Faculty of Law, Law, 2021
- Full Text:
- Date Issued: 2021-10-29
Views of the journey of grade 1 learners with barriers to learning, in the inclusive education system: a multi-level systemic investigation
- Van Vuuren, Cornelia Margaretha
- Authors: Van Vuuren, Cornelia Margaretha
- Date: 2022-10-04
- Subjects: Inclusive education South Africa Eastern Cape , Special education teachers South Africa Eastern Cape Attitudes , South Africa. Department of Education , Children with disabilities Education (Elementary) Government policy South Africa , Special education teachers Training of South Africa Eastern Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327122 , vital:61083 , DOI 10.21504/10962/327122
- Description: Embedded in South Africa’s humanitarian discourse, inclusive education (IE) followed global trends of inclusion of all people into wider society without discrimination. Inclusion in mainstream schools should also, according to the Salamanca agreement provide equal quality education, enabling learners with special educational needs (LSEN) to reach their full potential as a basic human right. IE started in South Africa with the implementation of the inclusive policy EWP6 in 2001. Including all children with barriers to learning in schools in their communities promoted social inclusion with their peers. The DoE introduced the Policy of Screening, Identification, Assessment and Support (SIAS) in 2014. This policy was implemented to assist teachers to identify learning barriers, as a means of offering support to these learners through the inclusive system. However, it seems that educators found this process cumbersome, without resources to maintain the process and with multiple systemic barriers preventing, rather than enhancing, support to LSEN. This multi-level systemic study explores the views of educators and other stakeholders on the effectiveness of the IE system in supporting LSEN, to serve the best interests of these learners in their first year of formal schooling. The study was conducted in three selected diverse mainstream Eastern Cape (EC) rural schools, involving the views of educators, district officials and parents. The study probed the impact of the inclusive system on LSEN’s development and social wellbeing, the perceived effects and benefits of the current system, and how the education model contributes towards human rights objectives and constitutional imperatives. The study acknowledges the theories and policies of the current inclusive system as promoting inclusion, but not being successfully realised in rural areas in the South African context, due to several systemic and contextual barriers. The findings revealed that although all participants noted the possible benefits of IE, the current system did not serve the individual educational needs of LSEN in rural mainstream schools, in their first formal year of schooling. Several constraints were reported including lack of resources, insufficient Allied Health support services, and insufficient training of educators. These lead to feelings of inadequacy in educators, along with systemic and contextual barriers and financial constraints in the schools. There also seems to be a need for better collaboration between education and other departments serving children and communities. To conclude, this study suggests a broader multi-level networked system, in which there needs to be greater interaction between the DoE and other government departments supporting children with barriers, like the Departments of Health (DoH), Social Development (DSD) and Justice (DoJ). , Thesis (PhD) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-10-04
- Authors: Van Vuuren, Cornelia Margaretha
- Date: 2022-10-04
- Subjects: Inclusive education South Africa Eastern Cape , Special education teachers South Africa Eastern Cape Attitudes , South Africa. Department of Education , Children with disabilities Education (Elementary) Government policy South Africa , Special education teachers Training of South Africa Eastern Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327122 , vital:61083 , DOI 10.21504/10962/327122
- Description: Embedded in South Africa’s humanitarian discourse, inclusive education (IE) followed global trends of inclusion of all people into wider society without discrimination. Inclusion in mainstream schools should also, according to the Salamanca agreement provide equal quality education, enabling learners with special educational needs (LSEN) to reach their full potential as a basic human right. IE started in South Africa with the implementation of the inclusive policy EWP6 in 2001. Including all children with barriers to learning in schools in their communities promoted social inclusion with their peers. The DoE introduced the Policy of Screening, Identification, Assessment and Support (SIAS) in 2014. This policy was implemented to assist teachers to identify learning barriers, as a means of offering support to these learners through the inclusive system. However, it seems that educators found this process cumbersome, without resources to maintain the process and with multiple systemic barriers preventing, rather than enhancing, support to LSEN. This multi-level systemic study explores the views of educators and other stakeholders on the effectiveness of the IE system in supporting LSEN, to serve the best interests of these learners in their first year of formal schooling. The study was conducted in three selected diverse mainstream Eastern Cape (EC) rural schools, involving the views of educators, district officials and parents. The study probed the impact of the inclusive system on LSEN’s development and social wellbeing, the perceived effects and benefits of the current system, and how the education model contributes towards human rights objectives and constitutional imperatives. The study acknowledges the theories and policies of the current inclusive system as promoting inclusion, but not being successfully realised in rural areas in the South African context, due to several systemic and contextual barriers. The findings revealed that although all participants noted the possible benefits of IE, the current system did not serve the individual educational needs of LSEN in rural mainstream schools, in their first formal year of schooling. Several constraints were reported including lack of resources, insufficient Allied Health support services, and insufficient training of educators. These lead to feelings of inadequacy in educators, along with systemic and contextual barriers and financial constraints in the schools. There also seems to be a need for better collaboration between education and other departments serving children and communities. To conclude, this study suggests a broader multi-level networked system, in which there needs to be greater interaction between the DoE and other government departments supporting children with barriers, like the Departments of Health (DoH), Social Development (DSD) and Justice (DoJ). , Thesis (PhD) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-10-04
Effect of Helicosporidium sp. (Chlorophyta; Trebouxiophyceae) infection on Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae), a biological control agent for the invasive Salvinia molesta D.S. Mitchell (Salviniaceae) in South
- Authors: Mphephu, Tshililo Emmanuel
- Date: 2022-10-14
- Subjects: Salvinia molesta South Africa , Weeds Biological control , Cyrtobagous salviniae , Ketoconazole
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365815 , vital:65792 , DOI https://doi.org/10.21504/10962/365815
- Description: The effectiveness of established biological control agents depends on biotic and abiotic interactions in the introduced range. The weevil, Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae), was released as a biological control against Salvinia molesta D.S. Mitchell (Salviniaceae) in South Africa in 1985. This agent has been highly successful against S. molesta and has significantly reduced the weed’s populations around the country. However, in 2007, the parasitic alga, Helicosporidium sp. (an undescribed species), was detected in field-collected C. salviniae adults in South Africa. The distribution and impacts of this disease on the weevil and its efficacy as a control agent were not known. In this thesis, the prevalence, infection load, and impact of Helicosporidium sp. on C. salviniae was determined. In 2019, adult weevils were collected from 10 sites across the Eastern Cape, KwaZulu-Natal, Limpopo, and Western Cape provinces and screened to determine the occurrence, infection load, and geographic distribution of Helicosporidium sp. Transmission mechanisms of this disease in C. salviniae were then evaluated. The possible impact of Helicosporidium sp. was assessed by comparing the feeding rates and the reproductive output of the diseased and healthy adults of C. salviniae. An attempt was then made to eliminate the disease in C. salviniae through the application of the antibiotic, ketoconazole. Further, the role of temperature on infection load in C. salviniae was also assessed. Finally, recommendations for the long-term biological control programme against S. molesta in South Africa were made. The disease covers the entire distribution range of C. salviniae in South Africa, with the disease occurrence rate ranging from 92.15% to 100% insects infected per site. Helicosporidium sp. was found to transmit vertically within the populations of C. salviniae. Infection by the Helicosporidium sp. disease reduced the reproductive output of C. salviniae as well its impact on biomass reduction of S. molesta when a diseased culture was compared to a healthy culture from the USA. 98.44 to 98.55% of Helicosporidium sp. loads were reduced through multiple applications of ketoconazole concentrations under in vitro trials. In vivo treatments resulted in 70% control of Helicosporidium sp. in the adults of C. salviniae that were fed ketoconazole three times over a 21 day period. Adult C. salviniae feeding and survival performances were similar when fed fronds of S. molesta inoculated with ketoconazole and water. The lowest and highest disease loads of Helicosporidium sp. were recorded when the weevils were reared at 30°C and 14°C, respectively. As expected, the highest impact and reproductive output of C. salviniae were at 30°C. The evaluations discussed in this thesis highlight the role of diseases in biological control agents, and gaps in both the pre-release and post-release monitoring that should integrate screening of diseases in these studies. Although the combined application of the antibiotic and temperature will reduce Helicosporidium sp. loads and impact, this technology is most likely only applicable where the weevils are reared in small numbers in a rearing facility and not really applicable to the field situation. It is important to release healthy agents that will cause efficient control of the target weed plant species, therefore, when introducing new biological control agents, the health status of such agents needs to be understood. Therefore, long-term field monitoring and assessment of the impact of C. salviniae on S. molesta should be conducted to track all the changes that may result due to the presence of Helicosporidium sp. This long-term monitoring and assessment will give a more informative role of Helicosporidium sp. in field populations of C. salviniae. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mphephu, Tshililo Emmanuel
- Date: 2022-10-14
- Subjects: Salvinia molesta South Africa , Weeds Biological control , Cyrtobagous salviniae , Ketoconazole
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365815 , vital:65792 , DOI https://doi.org/10.21504/10962/365815
- Description: The effectiveness of established biological control agents depends on biotic and abiotic interactions in the introduced range. The weevil, Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae), was released as a biological control against Salvinia molesta D.S. Mitchell (Salviniaceae) in South Africa in 1985. This agent has been highly successful against S. molesta and has significantly reduced the weed’s populations around the country. However, in 2007, the parasitic alga, Helicosporidium sp. (an undescribed species), was detected in field-collected C. salviniae adults in South Africa. The distribution and impacts of this disease on the weevil and its efficacy as a control agent were not known. In this thesis, the prevalence, infection load, and impact of Helicosporidium sp. on C. salviniae was determined. In 2019, adult weevils were collected from 10 sites across the Eastern Cape, KwaZulu-Natal, Limpopo, and Western Cape provinces and screened to determine the occurrence, infection load, and geographic distribution of Helicosporidium sp. Transmission mechanisms of this disease in C. salviniae were then evaluated. The possible impact of Helicosporidium sp. was assessed by comparing the feeding rates and the reproductive output of the diseased and healthy adults of C. salviniae. An attempt was then made to eliminate the disease in C. salviniae through the application of the antibiotic, ketoconazole. Further, the role of temperature on infection load in C. salviniae was also assessed. Finally, recommendations for the long-term biological control programme against S. molesta in South Africa were made. The disease covers the entire distribution range of C. salviniae in South Africa, with the disease occurrence rate ranging from 92.15% to 100% insects infected per site. Helicosporidium sp. was found to transmit vertically within the populations of C. salviniae. Infection by the Helicosporidium sp. disease reduced the reproductive output of C. salviniae as well its impact on biomass reduction of S. molesta when a diseased culture was compared to a healthy culture from the USA. 98.44 to 98.55% of Helicosporidium sp. loads were reduced through multiple applications of ketoconazole concentrations under in vitro trials. In vivo treatments resulted in 70% control of Helicosporidium sp. in the adults of C. salviniae that were fed ketoconazole three times over a 21 day period. Adult C. salviniae feeding and survival performances were similar when fed fronds of S. molesta inoculated with ketoconazole and water. The lowest and highest disease loads of Helicosporidium sp. were recorded when the weevils were reared at 30°C and 14°C, respectively. As expected, the highest impact and reproductive output of C. salviniae were at 30°C. The evaluations discussed in this thesis highlight the role of diseases in biological control agents, and gaps in both the pre-release and post-release monitoring that should integrate screening of diseases in these studies. Although the combined application of the antibiotic and temperature will reduce Helicosporidium sp. loads and impact, this technology is most likely only applicable where the weevils are reared in small numbers in a rearing facility and not really applicable to the field situation. It is important to release healthy agents that will cause efficient control of the target weed plant species, therefore, when introducing new biological control agents, the health status of such agents needs to be understood. Therefore, long-term field monitoring and assessment of the impact of C. salviniae on S. molesta should be conducted to track all the changes that may result due to the presence of Helicosporidium sp. This long-term monitoring and assessment will give a more informative role of Helicosporidium sp. in field populations of C. salviniae. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-10-14
Synthesis, characterization and host-guest complexes of supramolecular assemblies based on calixarenes and cucurbiturils
- Authors: Baa, Ebenezer
- Date: 2022-10-14
- Subjects: Supramolecular chemistry , Calixarenes , Cucurbiturils , Metal-organic frameworks , Macrocyclic compounds , Drug delivery systems
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365621 , vital:65765 , DOI https://doi.org/10.21504/10962/365621
- Description: The field of supramolecular chemistry has grown large and wide in both deepness of understanding, range of topics covered and scope and applications. Supramolecular self-assemblies are facilitated by a wide range of non-covalent intra and inter molecular interactions that range from hydrogen bonding to π-interaction and van der Waals. Macrocyclic compounds such as cucurbiturils and calixarenes have emerged as important classes of compounds with excellent potential of forming supramolecular assemblies. The porous nature of these compounds enables them to form host-guest supramolecular complexes stabilized by diverse range of non-covalent interactions. Furthermore, these compounds contain donor atoms capable of forming bonds with metal ions to yield metal complexes with interesting porous characteristics that deviate from their traditional hydrophobic cavity. The versatile nature of the resulting pores imply that they can accommodate diverse types of guests. This work explores the synthesis and characterization of a host of calixarenes and cucurbiturils. Self-assembly of these macrocycles with various metal ions results to the formation of porous metal organic framework (MOF) complexes. Four new calixarene typed compounds obtained from aromatic aldehydes and twenty-six cucurbituril metal complexes are reported. These macrocylces and their metal complexes also form supramolecular complexes with DMSO, methanol, isoniazid hydrochloride and ciprofloxacin hydrochlorides through either self-assembly, mechanochemistry and exposure to solvent vapors. The bulk materials have been characterized using nuclear magnetic resonance spectroscopy (NMR), Fourier transformed infrared spectroscopy (FTIR), powder and single crystal diffraction techniques and thermal studies thermogravimetric analysis (TGA) and differential thermal calorimetry (DSC). Data obtained from this study reveals that calixarenes can form supramolecular complexes with a frequently used laboratory solvents with BN22 showing appreciable selectivity for DMSO sorption from a solvent mixture. These compounds also form supramolecular complexes with drug molecules such as isoniazid and ciprofloxacin. Furthermore, the data reveals that choice of synthetic route of supramolecular ensembles dictates if the guest drug molecule will occupy the intrinsic or extrinsic pores of cucurbituril complexes. Biological studies on the obtained complexes reveal that the cucurbituril complexes are non-cytotoxic while the calixarenes show antibacterial activity against Escherichia coli and Staphylococcus aureus. Additionally, the study showed that ciprofloxacin can be successfully released from a calixarene host in a simulated body fluid although the host was also found to cross the dialysis membrane. The results of this study are important in that; - they can be exploited and developed in the selective sorption of certain guests and - that they can be used in the development of drug delivery systems that play a dual role of delivery and therapeutic activity. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Baa, Ebenezer
- Date: 2022-10-14
- Subjects: Supramolecular chemistry , Calixarenes , Cucurbiturils , Metal-organic frameworks , Macrocyclic compounds , Drug delivery systems
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365621 , vital:65765 , DOI https://doi.org/10.21504/10962/365621
- Description: The field of supramolecular chemistry has grown large and wide in both deepness of understanding, range of topics covered and scope and applications. Supramolecular self-assemblies are facilitated by a wide range of non-covalent intra and inter molecular interactions that range from hydrogen bonding to π-interaction and van der Waals. Macrocyclic compounds such as cucurbiturils and calixarenes have emerged as important classes of compounds with excellent potential of forming supramolecular assemblies. The porous nature of these compounds enables them to form host-guest supramolecular complexes stabilized by diverse range of non-covalent interactions. Furthermore, these compounds contain donor atoms capable of forming bonds with metal ions to yield metal complexes with interesting porous characteristics that deviate from their traditional hydrophobic cavity. The versatile nature of the resulting pores imply that they can accommodate diverse types of guests. This work explores the synthesis and characterization of a host of calixarenes and cucurbiturils. Self-assembly of these macrocycles with various metal ions results to the formation of porous metal organic framework (MOF) complexes. Four new calixarene typed compounds obtained from aromatic aldehydes and twenty-six cucurbituril metal complexes are reported. These macrocylces and their metal complexes also form supramolecular complexes with DMSO, methanol, isoniazid hydrochloride and ciprofloxacin hydrochlorides through either self-assembly, mechanochemistry and exposure to solvent vapors. The bulk materials have been characterized using nuclear magnetic resonance spectroscopy (NMR), Fourier transformed infrared spectroscopy (FTIR), powder and single crystal diffraction techniques and thermal studies thermogravimetric analysis (TGA) and differential thermal calorimetry (DSC). Data obtained from this study reveals that calixarenes can form supramolecular complexes with a frequently used laboratory solvents with BN22 showing appreciable selectivity for DMSO sorption from a solvent mixture. These compounds also form supramolecular complexes with drug molecules such as isoniazid and ciprofloxacin. Furthermore, the data reveals that choice of synthetic route of supramolecular ensembles dictates if the guest drug molecule will occupy the intrinsic or extrinsic pores of cucurbituril complexes. Biological studies on the obtained complexes reveal that the cucurbituril complexes are non-cytotoxic while the calixarenes show antibacterial activity against Escherichia coli and Staphylococcus aureus. Additionally, the study showed that ciprofloxacin can be successfully released from a calixarene host in a simulated body fluid although the host was also found to cross the dialysis membrane. The results of this study are important in that; - they can be exploited and developed in the selective sorption of certain guests and - that they can be used in the development of drug delivery systems that play a dual role of delivery and therapeutic activity. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-10-14
Land use decision-making on residential plots in Fingo Village, Makhanda (Grahamstown), South Africa
- Authors: Memela, Sinenhlanhla
- Date: 2021-04-28
- Subjects: Land use South Africa Makhanda Decision making , Land use, Urban South Africa Makhanda Decision making , Residential real estate South Africa Makhanda , Urban ecology (Sociology) South Africa Makhanda , Urban gardening South Africa Makhanda , Urban livestock production systems South Africa Makhanda
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/322694 , vital:60589 , DOI 10.21504/10962/322694
- Description: This study seeks to understand land use decision-making dynamics on large residential plots in Fingo Village, Makhanda (Grahamstown). Fingo Village was selected as a study area because it is one of the poorest urban settings in South Africa where urban poverty is observed alongside access to land. A dominant economic perspective not only suggests that land use decisions are motivated by economic motives, but also implies that access to land would enable people to generate income from its use to improve their livelihoods. This study argues against an uncritical embrace of this assumption. Lefebvre’s production of space thesis provides a holistic understanding of the factors involved in the making of land use decisions. The focus of this study is on the dialectic process in the spatial triad– spatial practice, representational space and representations of space. This involved the reading of government policies and legislation together with local lived experiences to gain an understanding of the particular spatial practices seen in Fingo Village. Snowball and convenience sampling were used to select 36 household plots in Fingo Village. Primary data was gathered by means of semi-structured interviews and participatory mapping while additional information was sourced from secondary sources and desktop analysis. The findings of the study show that there is no uniform pattern of land use and success. Different land use activities found on the selected residential plots, including the main house, backyard flat or flats, spaza shops, a funeral parlour, livestock keeping, cultural use (a kraal for ancestral worship) and food gardening. These activities are motivated by residents’ perceptions and attitudes towards their spaces, as well as the value and meaning they attach to the land which is not limited to economic factors, but is also influenced by socio-cultural, political and biophysical considerations. Although some spatial practices are prohibited by the government, they are important to the residents. Other participants fail to use the land as would be expected by a conventional economic perspective, due to spatial conflict relating to different interests as a result of collective land ownership and the failure of municipalities to enforce policies and regulations. The fact that numerous factors influence households’ land use decisions means that access to land does not always directly translate into economic benefits. It is all about what people think or do about their land, as well as what the state lays out in terms of policy and legislation, that will influence whether those people with large plots of land will ‘prosper’ or not. , Thesis (PhD) -- Faculty of Science, Geography, 2021
- Full Text:
- Date Issued: 2021-04-28
Land use decision-making on residential plots in Fingo Village, Makhanda (Grahamstown), South Africa
- Authors: Memela, Sinenhlanhla
- Date: 2021-04-28
- Subjects: Land use South Africa Makhanda Decision making , Land use, Urban South Africa Makhanda Decision making , Residential real estate South Africa Makhanda , Urban ecology (Sociology) South Africa Makhanda , Urban gardening South Africa Makhanda , Urban livestock production systems South Africa Makhanda
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/322694 , vital:60589 , DOI 10.21504/10962/322694
- Description: This study seeks to understand land use decision-making dynamics on large residential plots in Fingo Village, Makhanda (Grahamstown). Fingo Village was selected as a study area because it is one of the poorest urban settings in South Africa where urban poverty is observed alongside access to land. A dominant economic perspective not only suggests that land use decisions are motivated by economic motives, but also implies that access to land would enable people to generate income from its use to improve their livelihoods. This study argues against an uncritical embrace of this assumption. Lefebvre’s production of space thesis provides a holistic understanding of the factors involved in the making of land use decisions. The focus of this study is on the dialectic process in the spatial triad– spatial practice, representational space and representations of space. This involved the reading of government policies and legislation together with local lived experiences to gain an understanding of the particular spatial practices seen in Fingo Village. Snowball and convenience sampling were used to select 36 household plots in Fingo Village. Primary data was gathered by means of semi-structured interviews and participatory mapping while additional information was sourced from secondary sources and desktop analysis. The findings of the study show that there is no uniform pattern of land use and success. Different land use activities found on the selected residential plots, including the main house, backyard flat or flats, spaza shops, a funeral parlour, livestock keeping, cultural use (a kraal for ancestral worship) and food gardening. These activities are motivated by residents’ perceptions and attitudes towards their spaces, as well as the value and meaning they attach to the land which is not limited to economic factors, but is also influenced by socio-cultural, political and biophysical considerations. Although some spatial practices are prohibited by the government, they are important to the residents. Other participants fail to use the land as would be expected by a conventional economic perspective, due to spatial conflict relating to different interests as a result of collective land ownership and the failure of municipalities to enforce policies and regulations. The fact that numerous factors influence households’ land use decisions means that access to land does not always directly translate into economic benefits. It is all about what people think or do about their land, as well as what the state lays out in terms of policy and legislation, that will influence whether those people with large plots of land will ‘prosper’ or not. , Thesis (PhD) -- Faculty of Science, Geography, 2021
- Full Text:
- Date Issued: 2021-04-28
An exploration of the mathematical learner identities of high school learners who participated in after school mathematics clubs in primary school
- Authors: Hokonya, Wellington Munetsi
- Date: 2021-10-29
- Subjects: Mathematics Study and teaching (Secondary) South Africa , Mathematics Study and teaching (Elementary) Activity programs South Africa , Identity (Psychology) in children , After-school programs South Africa , School children Attitudes , Mathematics Study and teaching Psychological aspects South Africa , South African Numeracy Chair Project (SANCP)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/189985 , vital:44953 , 10.21504/10962/189985
- Description: This study focuses on understanding mathematics learner identities of high school learners who participated in the South African Numeracy Chair Project after school mathematics clubs, an environment that afforded different mathematics identities from the traditional South African classroom. Mathematics learner identities feature prominently in current research on mathematics education because they affect whether and how learners engage in mathematics. They play a critical role in enhancing (or detracting from) learners’ attitudes, dispositions, emotional development, and general sense of self as they learn mathematics. Development of positive learner mathematical identity is therefore useful in making learners commit to their mathematics work. South African primary mathematics education is described as being in a state of crisis, and various programmes are being implemented to develop intervention models to improve quality and ensure the effective teaching and learning of primary mathematics. The South African Numeracy Chair Project initiative at Rhodes University provides for longitudinal research and development programmes with primary mathematics teachers and learners from previously disadvantaged schools, in order to find ways of mitigating the crisis. The after school mathematics clubs provide extra-curricular activities focused on developing a supportive learning community where learners’ active mathematical participation, engagement, enjoyment, and sense making are the focus. The clubs provide a supportive learning environment that is different to the traditional classroom and in which learners can participate actively and freely in mathematical activities. The study explores the nature of mathematics learner identities as learning trajectories that connect the past and future in negotiation of the present. It also seeks to discover how primary school club participation and experiences feature in the learners’ mathematical identities. The study employs two theoretical frameworks to analyse qualitative data that was gathered in the form of spoken and written stories, by 14 learners who participated in the after school mathematics clubs in primary school. The stories covered learners’ engagement in mathematics in different landscapes of practice that promoted the construction of different learner mathematical identities. A close analysis of the qualitative data revealed that learners’ mathematical identities are heavily influenced by the values that were foregrounded in the after school mathematics clubs. The clubs valued hard work and encouraged learners to ask for assistance when in doubt. In line with the club ethos, the learners storied resilience and hard work in their narratives. In addition, although many learners storied Mathematics as difficult in high school, they chose to continue taking the subject. , Thesis (PhD) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Hokonya, Wellington Munetsi
- Date: 2021-10-29
- Subjects: Mathematics Study and teaching (Secondary) South Africa , Mathematics Study and teaching (Elementary) Activity programs South Africa , Identity (Psychology) in children , After-school programs South Africa , School children Attitudes , Mathematics Study and teaching Psychological aspects South Africa , South African Numeracy Chair Project (SANCP)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/189985 , vital:44953 , 10.21504/10962/189985
- Description: This study focuses on understanding mathematics learner identities of high school learners who participated in the South African Numeracy Chair Project after school mathematics clubs, an environment that afforded different mathematics identities from the traditional South African classroom. Mathematics learner identities feature prominently in current research on mathematics education because they affect whether and how learners engage in mathematics. They play a critical role in enhancing (or detracting from) learners’ attitudes, dispositions, emotional development, and general sense of self as they learn mathematics. Development of positive learner mathematical identity is therefore useful in making learners commit to their mathematics work. South African primary mathematics education is described as being in a state of crisis, and various programmes are being implemented to develop intervention models to improve quality and ensure the effective teaching and learning of primary mathematics. The South African Numeracy Chair Project initiative at Rhodes University provides for longitudinal research and development programmes with primary mathematics teachers and learners from previously disadvantaged schools, in order to find ways of mitigating the crisis. The after school mathematics clubs provide extra-curricular activities focused on developing a supportive learning community where learners’ active mathematical participation, engagement, enjoyment, and sense making are the focus. The clubs provide a supportive learning environment that is different to the traditional classroom and in which learners can participate actively and freely in mathematical activities. The study explores the nature of mathematics learner identities as learning trajectories that connect the past and future in negotiation of the present. It also seeks to discover how primary school club participation and experiences feature in the learners’ mathematical identities. The study employs two theoretical frameworks to analyse qualitative data that was gathered in the form of spoken and written stories, by 14 learners who participated in the after school mathematics clubs in primary school. The stories covered learners’ engagement in mathematics in different landscapes of practice that promoted the construction of different learner mathematical identities. A close analysis of the qualitative data revealed that learners’ mathematical identities are heavily influenced by the values that were foregrounded in the after school mathematics clubs. The clubs valued hard work and encouraged learners to ask for assistance when in doubt. In line with the club ethos, the learners storied resilience and hard work in their narratives. In addition, although many learners storied Mathematics as difficult in high school, they chose to continue taking the subject. , Thesis (PhD) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
An examination of activism and ‘political listening’ during the year of student protest at the University of Cape Town from 9 March 2015 to 9 March 2016
- Mufamadi, Azwihangwisi Eugene
- Authors: Mufamadi, Azwihangwisi Eugene
- Date: 2022-10-04
- Subjects: Student movements South Africa Cape Town , Democracy South Africa , Listening Political aspects , Journalistic ethics , Journalism Political aspects , Communication in social action South Africa Cape Town , University of Cape Town , Cape Times Ltd.
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327144 , vital:61085 , DOI 10.21504/10962/327144
- Description: This study sets out to examine democratic participation in South Africa and the role that ‘political listening’ could play in making participation more equitable. It considers protest action on a South African university campus, which at times not only resulted in significant and swift concessions from the university leadership but also sparked national political action which got an equally swift response from the South African government. It considers the social movement, the RhodesMustFall movement (RMF), as one way in which students can organise themselves to get a better hearing from the University of Cape Town (UCT) management in their attempt to make a meaningful contribution to the university’s micro democracy. This study examines whether the interaction between the UCT management and RMF could be considered ‘political listening’, and the possible role of the Cape Times newspaper within this context of participation. Using data gathered through interviews, written communications, observation and newspaper articles, the study shows that in all of the interactions between RMF and the UCT management, both groups were seldom willing to forego their power to engage in genuine listening. Instead, the two parties guessed at what power the other party might have and acted to reduce that power. It is in this context of guessing at and figuring what power the other party has that listening occurs. Furthermore, the study shows that during the RMF protest, the UCT management viewed their responsibility for the institution mainly through the lens of Private Property Law which framed protest as something to be dealt with by restoring law and order. The study also details the role of the Cape Times newspaper in the interactions between RMF and the UCT management and considers if this role could be political listening. The study is exploratory and demonstrates how political listening could work more optimally in real-life instances. , Thesis (PhD) -- Faculty of Humanities, Journalism and Media Studies, 2022
- Full Text:
- Date Issued: 2022-10-04
- Authors: Mufamadi, Azwihangwisi Eugene
- Date: 2022-10-04
- Subjects: Student movements South Africa Cape Town , Democracy South Africa , Listening Political aspects , Journalistic ethics , Journalism Political aspects , Communication in social action South Africa Cape Town , University of Cape Town , Cape Times Ltd.
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327144 , vital:61085 , DOI 10.21504/10962/327144
- Description: This study sets out to examine democratic participation in South Africa and the role that ‘political listening’ could play in making participation more equitable. It considers protest action on a South African university campus, which at times not only resulted in significant and swift concessions from the university leadership but also sparked national political action which got an equally swift response from the South African government. It considers the social movement, the RhodesMustFall movement (RMF), as one way in which students can organise themselves to get a better hearing from the University of Cape Town (UCT) management in their attempt to make a meaningful contribution to the university’s micro democracy. This study examines whether the interaction between the UCT management and RMF could be considered ‘political listening’, and the possible role of the Cape Times newspaper within this context of participation. Using data gathered through interviews, written communications, observation and newspaper articles, the study shows that in all of the interactions between RMF and the UCT management, both groups were seldom willing to forego their power to engage in genuine listening. Instead, the two parties guessed at what power the other party might have and acted to reduce that power. It is in this context of guessing at and figuring what power the other party has that listening occurs. Furthermore, the study shows that during the RMF protest, the UCT management viewed their responsibility for the institution mainly through the lens of Private Property Law which framed protest as something to be dealt with by restoring law and order. The study also details the role of the Cape Times newspaper in the interactions between RMF and the UCT management and considers if this role could be political listening. The study is exploratory and demonstrates how political listening could work more optimally in real-life instances. , Thesis (PhD) -- Faculty of Humanities, Journalism and Media Studies, 2022
- Full Text:
- Date Issued: 2022-10-04
Schema modes in eating disorders: an interpretative phenomenological analysis
- Authors: Bowker, Chantal Ann
- Date: 2021-10-29
- Subjects: Eating disorders , Anorexia nervosa , Bulimia , Compulsive eating , Schema-focused cognitive therapy , Interpretative phenomenological analysis (IPA)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/196072 , vital:45723 , DOI 10.21504/10962/196072
- Description: The DSM-5 prevalence rate of anorexia nervosa is 0.4%, bulimia nervosa is 1% to 1.5%, and binge eating disorder is 1.6% (American Psychiatric Association, 2013). Although treatment approaches for eating disorders have high drop-out rates and low rates of recovery, treatment modalities that address childhood factors contributing to the eating disorder, as well as the eating disorder behaviours, have better outcomes. Schema therapy is an integrative approach that has been used for the treatment of eating disorders for more than a decade. Central features in schema therapy include the identification of early maladaptive schemas arising from unmet needs and schema modes. Schema modes, composed of schemas and coping mechanisms, are active for an individual at a particular time in response to triggers in the environment (Brown et al., 2016). Identifying an individual’s modes is a crucial aspect that reflects the underlying structure of the individual’s creation of reality. A phenomenological understanding of the modes is essential for developing a case conceptualisation and treatment plan. Differences exist in the naming and description of modes in the current schema therapy literature, which suggests the need for a phenomenological investigation of these structures. This research study used a mostly qualitative approach, in the form of clinical interviews, substantiated by questionnaires, to examine schema modes. Case presentations using the schema therapy model are provided for five women with either anorexia nervosa, bulimia nervosa or binge eating disorder. Then, through a process of interpretative phenomenological analysis, specific modes are examined as to how they are experienced by the participants and influence their behaviour. The features of schema modes in these clinical cases are compared to the existing literature to extend the understanding of schema modes in eating disorders. The participants’ experiences revealed that they had schema modes in common, regardless of the eating disorder presentation, but that the features of the individual modes varied. Modes found in the current literature such as the Detached Self-Soother and Perfectionist Overcontroller coping mode, were found in all the participants. Four of the five participants had an Eating Disordered Overcontroller mode. Features consistent with the existing descriptions of the Perfectionist Overcontroller, Eating Disordered Overcontroller and Detached Self-Soother modes were noted, and new features were identified. The Perfectionist Overcontroller and Eating Disordered Overcontroller have been presented here as complex composite modes with sub-modes that work together in a coherent way in the service of the same project (Edwards, 2020b). Twenty-three features are identified in the parent modes. Blended parent modes, with multiple features active in a situation, were described. The blended parent modes expand on the existing literature on parent modes. The findings in this research support and extend the mode structure identified in the schema therapy theory, and highlight the idiosyncratic nature of the modes. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Bowker, Chantal Ann
- Date: 2021-10-29
- Subjects: Eating disorders , Anorexia nervosa , Bulimia , Compulsive eating , Schema-focused cognitive therapy , Interpretative phenomenological analysis (IPA)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/196072 , vital:45723 , DOI 10.21504/10962/196072
- Description: The DSM-5 prevalence rate of anorexia nervosa is 0.4%, bulimia nervosa is 1% to 1.5%, and binge eating disorder is 1.6% (American Psychiatric Association, 2013). Although treatment approaches for eating disorders have high drop-out rates and low rates of recovery, treatment modalities that address childhood factors contributing to the eating disorder, as well as the eating disorder behaviours, have better outcomes. Schema therapy is an integrative approach that has been used for the treatment of eating disorders for more than a decade. Central features in schema therapy include the identification of early maladaptive schemas arising from unmet needs and schema modes. Schema modes, composed of schemas and coping mechanisms, are active for an individual at a particular time in response to triggers in the environment (Brown et al., 2016). Identifying an individual’s modes is a crucial aspect that reflects the underlying structure of the individual’s creation of reality. A phenomenological understanding of the modes is essential for developing a case conceptualisation and treatment plan. Differences exist in the naming and description of modes in the current schema therapy literature, which suggests the need for a phenomenological investigation of these structures. This research study used a mostly qualitative approach, in the form of clinical interviews, substantiated by questionnaires, to examine schema modes. Case presentations using the schema therapy model are provided for five women with either anorexia nervosa, bulimia nervosa or binge eating disorder. Then, through a process of interpretative phenomenological analysis, specific modes are examined as to how they are experienced by the participants and influence their behaviour. The features of schema modes in these clinical cases are compared to the existing literature to extend the understanding of schema modes in eating disorders. The participants’ experiences revealed that they had schema modes in common, regardless of the eating disorder presentation, but that the features of the individual modes varied. Modes found in the current literature such as the Detached Self-Soother and Perfectionist Overcontroller coping mode, were found in all the participants. Four of the five participants had an Eating Disordered Overcontroller mode. Features consistent with the existing descriptions of the Perfectionist Overcontroller, Eating Disordered Overcontroller and Detached Self-Soother modes were noted, and new features were identified. The Perfectionist Overcontroller and Eating Disordered Overcontroller have been presented here as complex composite modes with sub-modes that work together in a coherent way in the service of the same project (Edwards, 2020b). Twenty-three features are identified in the parent modes. Blended parent modes, with multiple features active in a situation, were described. The blended parent modes expand on the existing literature on parent modes. The findings in this research support and extend the mode structure identified in the schema therapy theory, and highlight the idiosyncratic nature of the modes. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
Application of computer-aided drug design for identification of P. falciparum inhibitors
- Authors: Diallo, Bakary N’tji
- Date: 2021-10-29
- Subjects: Plasmodium falciparum , Malaria -- Chemotherapy , Molecular dynamics , Antimalarials , Cheminformatics , Drug development , Ligand binding (Biochemistry) , Plasmodium falciparum1-deoxy-D-xylulose-5-phosphate reductoisomerase (PfDXR) , South African Natural Compounds Database
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192798 , vital:45265 , 10.21504/10962/192798
- Description: Malaria is a millennia-old disease with the first recorded cases dating back to 2700 BC found in Chinese medical records, and later in other civilizations. It has claimed human lives to such an extent that there are a notable associated socio-economic consequences. Currently, according to the World Health Organization (WHO), Africa holds the highest disease burden with 94% of deaths and 82% of cases with P. falciparum having ~100% prevalence. Chemotherapy, such as artemisinin combination therapy, has been and continues to be the work horse in the fight against the disease, together with seasonal malaria chemoprevention and the use of insecticides. Natural products such as quinine and artemisinin are particularly important in terms of their antimalarial activity. The emphasis in current chemotherapy research is the need for time and cost-effective workflows focussed on new mechanisms of action (MoAs) covering the target candidate profiles (TCPs). Despite a decline in cases over the past decades with, countries increasingly becoming certified malaria free, a stalling trend has been observed in the past five years resulting in missing the 2020 Global Technical Strategy (GTS) milestones. With no effective vaccine, a reduction in funding, slower drug approval than resistance emergence from resistant and invasive vectors, and threats in diagnosis with the pfhrp2/3 gene deletion, malaria remains a major health concern. Motivated by these reasons, the primary aim of this work was a contribution to the antimalarial pipeline through in silico approaches focusing on P. falciparum. We first intended an exploration of malarial targets through a proteome scale screening on 36 targets using multiple metrics to account for the multi-objective nature of drug discovery. The continuous growth of structural data offers the ideal scenario for mining new MoAs covering antimalarials TCPs. This was combined with a repurposing strategy using a set of orally available FDA approved drugs. Further, use was made of time- and cost-effective strategies combining QVina-W efficiency metrics that integrate molecular properties, GRIM rescoring for molecular interactions and a hydrogen mass repartitioning (HMR) molecular dynamics (MD) scheme for accelerated development of antimalarials in the context of resistance. This pipeline further integrates a complex ranking for better drug-target selectivity, and normalization strategies to overcome docking scoring function bias. The different metrics, ranking, normalization strategies and their combinations were first assessed using their mean ranking error (MRE). A version combining all metrics was used to select 36 unique protein-ligand complexes, assessed in MD, with the final retention of 25. From the 16 in vitro tested hits of the 25, fingolimod, abiraterone, prazosin, and terazosin showed antiplasmodial activity with IC50 2.21, 3.37, 16.67 and 34.72 μM respectively and of these, only fingolimod was found to be not safe with respect to human cell viability. These compounds were predicted active on different molecular targets, abiraterone was predicted to interact with a putative liver-stage essential target, hence promising as a transmission-blocking agent. The pipeline had a promising 25% hit rate considering the proteome-scale and use of cost-effective approaches. Secondly, we focused on Plasmodium falciparum 1-deoxy-D-xylulose-5-phosphate reductoisomerase (PfDXR) using a more extensive screening pipeline to overcome some of the current in silico screening limitations. Starting from the ZINC lead-like library of ~3M, hierarchical ligand-based virtual screening (LBVS) and structure-based virtual screening (SBVS) approaches with molecular docking and re-scoring using eleven scoring functions (SFs) were used. Later ranking with an exponential consensus strategy was included. Selected hits were further assessed through Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA), advanced MD sampling in a ligand pulling simulations and (Weighted Histogram Analysis Method) WHAM analysis for umbrella sampling (US) to derive binding free energies. Four leads had better predicted affinities in US than LC5, a 280 nM potent PfDXR inhibitor with ZINC000050633276 showing a promising binding of -20.43 kcal/mol. As shown with fosmidomycin, DXR inhibition offers fast acting compounds fulfilling antimalarials TCP1. Yet, fosmidomycin has a high polarity causing its short half-life and hampering its clinical use. These leads scaffolds are different from fosmidomycin and hence may offer better pharmacokinetic and pharmacodynamic properties and may also be promising for lead optimization. A combined analysis of residues’ contributions to the free energy of binding in MM-PBSA and to steered molecular dynamics (SMD) Fmax indicated GLU233, CYS268, SER270, TRP296, and HIS341 as exploitable for compound optimization. Finally, we updated the SANCDB library with new NPs and their commercially available analogs as a solution to NP availability. The library is extended to 1005 compounds from its initial 600 compounds and the database is integrated to Mcule and Molport APIs for analogs automatic update. The new set may contribute to virtual screening and to antimalarials as the most effective ones have NP origin. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Diallo, Bakary N’tji
- Date: 2021-10-29
- Subjects: Plasmodium falciparum , Malaria -- Chemotherapy , Molecular dynamics , Antimalarials , Cheminformatics , Drug development , Ligand binding (Biochemistry) , Plasmodium falciparum1-deoxy-D-xylulose-5-phosphate reductoisomerase (PfDXR) , South African Natural Compounds Database
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192798 , vital:45265 , 10.21504/10962/192798
- Description: Malaria is a millennia-old disease with the first recorded cases dating back to 2700 BC found in Chinese medical records, and later in other civilizations. It has claimed human lives to such an extent that there are a notable associated socio-economic consequences. Currently, according to the World Health Organization (WHO), Africa holds the highest disease burden with 94% of deaths and 82% of cases with P. falciparum having ~100% prevalence. Chemotherapy, such as artemisinin combination therapy, has been and continues to be the work horse in the fight against the disease, together with seasonal malaria chemoprevention and the use of insecticides. Natural products such as quinine and artemisinin are particularly important in terms of their antimalarial activity. The emphasis in current chemotherapy research is the need for time and cost-effective workflows focussed on new mechanisms of action (MoAs) covering the target candidate profiles (TCPs). Despite a decline in cases over the past decades with, countries increasingly becoming certified malaria free, a stalling trend has been observed in the past five years resulting in missing the 2020 Global Technical Strategy (GTS) milestones. With no effective vaccine, a reduction in funding, slower drug approval than resistance emergence from resistant and invasive vectors, and threats in diagnosis with the pfhrp2/3 gene deletion, malaria remains a major health concern. Motivated by these reasons, the primary aim of this work was a contribution to the antimalarial pipeline through in silico approaches focusing on P. falciparum. We first intended an exploration of malarial targets through a proteome scale screening on 36 targets using multiple metrics to account for the multi-objective nature of drug discovery. The continuous growth of structural data offers the ideal scenario for mining new MoAs covering antimalarials TCPs. This was combined with a repurposing strategy using a set of orally available FDA approved drugs. Further, use was made of time- and cost-effective strategies combining QVina-W efficiency metrics that integrate molecular properties, GRIM rescoring for molecular interactions and a hydrogen mass repartitioning (HMR) molecular dynamics (MD) scheme for accelerated development of antimalarials in the context of resistance. This pipeline further integrates a complex ranking for better drug-target selectivity, and normalization strategies to overcome docking scoring function bias. The different metrics, ranking, normalization strategies and their combinations were first assessed using their mean ranking error (MRE). A version combining all metrics was used to select 36 unique protein-ligand complexes, assessed in MD, with the final retention of 25. From the 16 in vitro tested hits of the 25, fingolimod, abiraterone, prazosin, and terazosin showed antiplasmodial activity with IC50 2.21, 3.37, 16.67 and 34.72 μM respectively and of these, only fingolimod was found to be not safe with respect to human cell viability. These compounds were predicted active on different molecular targets, abiraterone was predicted to interact with a putative liver-stage essential target, hence promising as a transmission-blocking agent. The pipeline had a promising 25% hit rate considering the proteome-scale and use of cost-effective approaches. Secondly, we focused on Plasmodium falciparum 1-deoxy-D-xylulose-5-phosphate reductoisomerase (PfDXR) using a more extensive screening pipeline to overcome some of the current in silico screening limitations. Starting from the ZINC lead-like library of ~3M, hierarchical ligand-based virtual screening (LBVS) and structure-based virtual screening (SBVS) approaches with molecular docking and re-scoring using eleven scoring functions (SFs) were used. Later ranking with an exponential consensus strategy was included. Selected hits were further assessed through Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA), advanced MD sampling in a ligand pulling simulations and (Weighted Histogram Analysis Method) WHAM analysis for umbrella sampling (US) to derive binding free energies. Four leads had better predicted affinities in US than LC5, a 280 nM potent PfDXR inhibitor with ZINC000050633276 showing a promising binding of -20.43 kcal/mol. As shown with fosmidomycin, DXR inhibition offers fast acting compounds fulfilling antimalarials TCP1. Yet, fosmidomycin has a high polarity causing its short half-life and hampering its clinical use. These leads scaffolds are different from fosmidomycin and hence may offer better pharmacokinetic and pharmacodynamic properties and may also be promising for lead optimization. A combined analysis of residues’ contributions to the free energy of binding in MM-PBSA and to steered molecular dynamics (SMD) Fmax indicated GLU233, CYS268, SER270, TRP296, and HIS341 as exploitable for compound optimization. Finally, we updated the SANCDB library with new NPs and their commercially available analogs as a solution to NP availability. The library is extended to 1005 compounds from its initial 600 compounds and the database is integrated to Mcule and Molport APIs for analogs automatic update. The new set may contribute to virtual screening and to antimalarials as the most effective ones have NP origin. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-10-29
The construction of phthalocyanine- carbon nanoparticle conjugates for applications in photodynamic therapy and non-linear optics
- Matshitse, Refilwe Manyama Stephina
- Authors: Matshitse, Refilwe Manyama Stephina
- Date: 2021-10-29
- Subjects: Phthalocyanines , Nanodiamonds , Photochemotherapy , Nonlinear optics , Quantum dots
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/188397 , vital:44750 , 10.21504/10962/188397
- Description: The syntheses and characterization of symmetric and asymmetric Pcs functionalized at the peripheral position and sometimes positively charged are reported. The Pcs had either H2, zinc or silicon as central metals and have pyridyloxy, benzothiozole phenoxy, and respective cationic analogues as ring substituents. The Pcs were linked to carbon based nanoparticles such as graphene quantum dots, carbon dots, and detonation nanodiamonds (DNDs) via an ester, amide bond and/or π - π stacking. The physicochemical characteristics of the Pcs were assessed when alone and when in a conjugated system. Both symmetrically and asymmetrically substituted benzothiozole Pcs when quaternised displayed higher triplet and singlet oxygen quantum yields than their unquaternised counterparts. Linkage to carbon nanoparticles (especially to detonation nanodiamonds) had an increasing effect on triplet and singlet oxygen quantum yield. However, a general decrease in singlet oxygen quantum yield on linkage to doped detonation nanodiamonds was associated with the screening effect of DNDs. Heteroatom doped DNDs-Pc nanohybrids have less singlet oxygen than Pcs alone due to molecular structural stability associated with strain that is relatively reduced upon linking Pcs. The In vitro dark cytotoxicity and photodynamic therapy of selected Pc complexes and conjugates against MCF-7 cells was tested. All studied Pc complexes and conjugates showed minimum dark toxicity making them applicable for PDT. When Pc complexes are alone, there is less phototoxicity with >22% cell viability at concentrations ≤ 50 μg/mL relative to conjugates with <22% cell viability at concentrations ≤ 50 μg/mL. There was no direct relationship between PDT and singlet oxygen quantum yields. Nonlinear optical characteristics of complexes was improved upon conjugation of DNDs. Absorbance, input energy, percentage loading, central metal, substituent of Pc and nature of interaction (covalent, noncovalent) are amongst some of the factors that influence nonlinear absorption properties of materials used in this study. All materials followed reverse saturable absorption through two photon absorption mechanism at the excitation wavelength of 532 nm. Aggregates reduce excited state lifetime and Beff under high concentrations/absorbance. A direct relationship between absorbance and Beff of DNDs nanoconjugated systems at low concentrations result in increased optical limiting characteristics of materials. The findings from this work show the importance of linking (nonlinear optics and photodynamic therapy) and doping (photodynamic therapy) photosensitisers such as phthalocyanines and sometimes boron dipyrromethenes onto carbon based nanoparticles for the enhanced characteristics in variable applications. , Thesis (PhD) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Matshitse, Refilwe Manyama Stephina
- Date: 2021-10-29
- Subjects: Phthalocyanines , Nanodiamonds , Photochemotherapy , Nonlinear optics , Quantum dots
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/188397 , vital:44750 , 10.21504/10962/188397
- Description: The syntheses and characterization of symmetric and asymmetric Pcs functionalized at the peripheral position and sometimes positively charged are reported. The Pcs had either H2, zinc or silicon as central metals and have pyridyloxy, benzothiozole phenoxy, and respective cationic analogues as ring substituents. The Pcs were linked to carbon based nanoparticles such as graphene quantum dots, carbon dots, and detonation nanodiamonds (DNDs) via an ester, amide bond and/or π - π stacking. The physicochemical characteristics of the Pcs were assessed when alone and when in a conjugated system. Both symmetrically and asymmetrically substituted benzothiozole Pcs when quaternised displayed higher triplet and singlet oxygen quantum yields than their unquaternised counterparts. Linkage to carbon nanoparticles (especially to detonation nanodiamonds) had an increasing effect on triplet and singlet oxygen quantum yield. However, a general decrease in singlet oxygen quantum yield on linkage to doped detonation nanodiamonds was associated with the screening effect of DNDs. Heteroatom doped DNDs-Pc nanohybrids have less singlet oxygen than Pcs alone due to molecular structural stability associated with strain that is relatively reduced upon linking Pcs. The In vitro dark cytotoxicity and photodynamic therapy of selected Pc complexes and conjugates against MCF-7 cells was tested. All studied Pc complexes and conjugates showed minimum dark toxicity making them applicable for PDT. When Pc complexes are alone, there is less phototoxicity with >22% cell viability at concentrations ≤ 50 μg/mL relative to conjugates with <22% cell viability at concentrations ≤ 50 μg/mL. There was no direct relationship between PDT and singlet oxygen quantum yields. Nonlinear optical characteristics of complexes was improved upon conjugation of DNDs. Absorbance, input energy, percentage loading, central metal, substituent of Pc and nature of interaction (covalent, noncovalent) are amongst some of the factors that influence nonlinear absorption properties of materials used in this study. All materials followed reverse saturable absorption through two photon absorption mechanism at the excitation wavelength of 532 nm. Aggregates reduce excited state lifetime and Beff under high concentrations/absorbance. A direct relationship between absorbance and Beff of DNDs nanoconjugated systems at low concentrations result in increased optical limiting characteristics of materials. The findings from this work show the importance of linking (nonlinear optics and photodynamic therapy) and doping (photodynamic therapy) photosensitisers such as phthalocyanines and sometimes boron dipyrromethenes onto carbon based nanoparticles for the enhanced characteristics in variable applications. , Thesis (PhD) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10-29
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
Dynamics of charge movement in ∞-Al2O3:C,Mg using thermoluminescence phototransferred and optically stimulated luminescence
- Authors: Lontsi Sob, Aaron Joel
- Date: 2022-04-08
- Subjects: Thermoluminescence , Optically stimulated luminescence , Phototransfer , Deep traps , Phototransferred thermoluminescence (PTTL)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294607 , vital:57237 , DOI 10.21504/10962/294607
- Description: The dosimetric features of ∞-Al2O3:C,Mg have been investigated for unannealed and annealed samples. The unannealed sample is referred to as sample A whereas the samples annealed at 700, 900 and 1200°C for 15 minutes each are referred to as samples B, C and D respectively. A glow curve of unannealed ∞-Al2O3:C,Mg measured at 1°C/s after irradiation to 2.0 Gy consists of peaks at 43, 73, 164, 195, 246, 284, 336 and 374°C respectively. For sample B (annealed at 700°C), a glow curve measured at 1°C/s after irradiation to 3.0 Gy has peaks at 46, 76, 100, 170, 199, 290, 330 and 375°C whereas the glow curve of sample C (annealed at 900°C) recorded under the same conditions consists of peaks at 49, 80, 100, 174, 206, 235, 290, 335 and 375°C respectively. Sample D (annealed at 1200°C) is the most sensitive of the four samples. A glow curve of sample D measured at 1°C/s after irradiation to 0.2 Gy has peaks at 52, 82, 102, 174, 234, 288 and 384°C respectively. The peaks are labelled I-VIII in order of appearance. The 100°C peak, labelled IIa, is induced by annealing at or above 700°C. The dose response of these peaks was studied for doses within 0.1-8.2 Gy. The reported peaks follow first-order kinetics irrespective of annealing temperature. Peaks I-III of each sample are reproduced under phototransfer for preheating up to 400°C. For the unannealed sample, the reproduced peaks are labelled A1-A3 whereas for the annealed samples, they are labelled B1-B3, C1-C3 and D1-D3 respectively. The annealing-induced peak at 100°C is reproduced as B2a, C2a and D2a for samples B, C and D respectively. A PTTL peak labelled C2b or D2b is also observed near 140°C in samples C and D. In addition to these PTTL peaks, a PTTL peak corresponding to peak IV is also found for sample D and for the unannealed sample. As the corresponding conventional peaks, the PTTL peaks of each sample follow first-order kinetics. Peak I and its corresponding PTTL peak for each sample are unstable and fade to a minimal level after 300 s of storage time. On the other hand, peak II of each sample and its corresponding PTTL peak could still be observed with delay up to 5000 s. Peak III of the unannealed sample remains stable with storage time up to 48 hours. Irrespective of annealing, the trap corresponding to peak III is the most sensitive to optical stimulation. Time-dependent profiles of PTTL from unannealed and annealed ∞-Al2O3:C,Mg were also studied. The mathematical analysis of the PTTL time-response profiles is based on experimental results. The role of various electron traps in PTTL was determined by using pulse annealing and by monitoring the dependence of peak intensity on duration of illumination for peaks not removed by preheating. The presence and role of deep traps were further demonstrated with thermally assisted optically stimulated luminescence. For the unannealed sample, the activation energy for thermal assistance is 0.033 ± 0.001 eV and the activation energy for thermal i quenching is 1.043 ± 0.001 eV. For sample C, the activation energy for thermal assistance is 0.044 ± 0.003 eV whereas that for thermal quenching is 1.110 ± 0.006 eV. The values for the activation energy for thermal assistance are lower than those reported in literature. Only the values for the activation energy for thermal quenching are somewhat comparable to values reported elsewhere. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: Lontsi Sob, Aaron Joel
- Date: 2022-04-08
- Subjects: Thermoluminescence , Optically stimulated luminescence , Phototransfer , Deep traps , Phototransferred thermoluminescence (PTTL)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294607 , vital:57237 , DOI 10.21504/10962/294607
- Description: The dosimetric features of ∞-Al2O3:C,Mg have been investigated for unannealed and annealed samples. The unannealed sample is referred to as sample A whereas the samples annealed at 700, 900 and 1200°C for 15 minutes each are referred to as samples B, C and D respectively. A glow curve of unannealed ∞-Al2O3:C,Mg measured at 1°C/s after irradiation to 2.0 Gy consists of peaks at 43, 73, 164, 195, 246, 284, 336 and 374°C respectively. For sample B (annealed at 700°C), a glow curve measured at 1°C/s after irradiation to 3.0 Gy has peaks at 46, 76, 100, 170, 199, 290, 330 and 375°C whereas the glow curve of sample C (annealed at 900°C) recorded under the same conditions consists of peaks at 49, 80, 100, 174, 206, 235, 290, 335 and 375°C respectively. Sample D (annealed at 1200°C) is the most sensitive of the four samples. A glow curve of sample D measured at 1°C/s after irradiation to 0.2 Gy has peaks at 52, 82, 102, 174, 234, 288 and 384°C respectively. The peaks are labelled I-VIII in order of appearance. The 100°C peak, labelled IIa, is induced by annealing at or above 700°C. The dose response of these peaks was studied for doses within 0.1-8.2 Gy. The reported peaks follow first-order kinetics irrespective of annealing temperature. Peaks I-III of each sample are reproduced under phototransfer for preheating up to 400°C. For the unannealed sample, the reproduced peaks are labelled A1-A3 whereas for the annealed samples, they are labelled B1-B3, C1-C3 and D1-D3 respectively. The annealing-induced peak at 100°C is reproduced as B2a, C2a and D2a for samples B, C and D respectively. A PTTL peak labelled C2b or D2b is also observed near 140°C in samples C and D. In addition to these PTTL peaks, a PTTL peak corresponding to peak IV is also found for sample D and for the unannealed sample. As the corresponding conventional peaks, the PTTL peaks of each sample follow first-order kinetics. Peak I and its corresponding PTTL peak for each sample are unstable and fade to a minimal level after 300 s of storage time. On the other hand, peak II of each sample and its corresponding PTTL peak could still be observed with delay up to 5000 s. Peak III of the unannealed sample remains stable with storage time up to 48 hours. Irrespective of annealing, the trap corresponding to peak III is the most sensitive to optical stimulation. Time-dependent profiles of PTTL from unannealed and annealed ∞-Al2O3:C,Mg were also studied. The mathematical analysis of the PTTL time-response profiles is based on experimental results. The role of various electron traps in PTTL was determined by using pulse annealing and by monitoring the dependence of peak intensity on duration of illumination for peaks not removed by preheating. The presence and role of deep traps were further demonstrated with thermally assisted optically stimulated luminescence. For the unannealed sample, the activation energy for thermal assistance is 0.033 ± 0.001 eV and the activation energy for thermal i quenching is 1.043 ± 0.001 eV. For sample C, the activation energy for thermal assistance is 0.044 ± 0.003 eV whereas that for thermal quenching is 1.110 ± 0.006 eV. The values for the activation energy for thermal assistance are lower than those reported in literature. Only the values for the activation energy for thermal quenching are somewhat comparable to values reported elsewhere. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2022
- Full Text:
- Date Issued: 2022-04-08
Leveraging a peer-learning community and expert community members in the integration of indigenous knowledge into the learning and teaching of Grade 10 Chemistry on the rate of reactions
- Authors: Simasiku, Fredrick Simataa
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366211 , vital:65843 , DOI https://doi.org/10.21504/10962/366211
- Description: The integration of indigenous knowledge (IK) in science teaching in Namibia is part of the transformation agenda that hopes to revitalise and make science accessible and relevant to learners’ everyday life experiences. However, there seems to be contradictions between the intended curriculum, the enacted curriculum and the attained curriculum. This disjuncture is exacerbated in part by the fact that science teachers seem to be struggling to be cultural knowledge brokers. It is against this backdrop that this formative interventionist study sought to leverage a peer-learning community and expert community members in the integration of IK into the learning and teaching of Grade 10 Chemistry on the rate of reactions. To achieve this, we mobilised the indigenous technologies of preserving and pounding Mahangu and making Oshikundu to mediate learning of the rate of reactions. The study was guided by the broad overarching research question: How does a peer-learning community and expert community members leverage the integration of indigenous knowledge into the learning and teaching of Grade 10 Chemistry on the rate of reactions? In this study, I used two complementary paradigms, viz. the transformative research paradigm and the indigenous research paradigm. Within these paradigms, I employed a qualitative case study research design using the community of practice and participatory action research as research approaches. Five Grade 10 Chemistry teachers from three schools in the Ohangwena region were involved in this study. Data were generated through semi-structured interviews, co-analysis of curriculum documents, workshop presentations and discussions, practical demonstrations, participatory observation, lesson observation, stimulated recall interviews, and participants’ reflections. Vygotsky’s sociocultural theory and Shulman’s Pedagogical Content Knowledge (PCK) were employed as theoretical frameworks in this study. Additionally, within PCK, Mavhunga and Rollnick’s Topic-Specific Pedagogical Content Knowledge components were used as an analytical framework. I used an inductive-deductive approach to data analysis to come up with sub-themes and themes. The main finding of this study revealed that leveraging a peer-learning community and the expert community members (ECMs) empowered the Chemistry teachers involved in this study to be cultural knowledge brokers and their understanding of how to integrate IK in their teaching improved. Both their subject matter knowledge and pedagogical content knowledge improved through co-developing and enacting exemplar lessons that integrated IK from the expert community members as well as from their own environments. A main insight of this study is that Chemistry teachers should seek opportunities to create peer-learning communities that engage with expert community members who are the custodians of the cultural heritage. The study also shows that this approach will support them to become better cultural knowledge brokers and help their learners bridge the divide between school science and what they have learnt in their homes or community. , Thesis (PhD) -- Faculty of Education, Education, 2023
- Full Text:
- Date Issued: 2023-03-29
- Authors: Simasiku, Fredrick Simataa
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/366211 , vital:65843 , DOI https://doi.org/10.21504/10962/366211
- Description: The integration of indigenous knowledge (IK) in science teaching in Namibia is part of the transformation agenda that hopes to revitalise and make science accessible and relevant to learners’ everyday life experiences. However, there seems to be contradictions between the intended curriculum, the enacted curriculum and the attained curriculum. This disjuncture is exacerbated in part by the fact that science teachers seem to be struggling to be cultural knowledge brokers. It is against this backdrop that this formative interventionist study sought to leverage a peer-learning community and expert community members in the integration of IK into the learning and teaching of Grade 10 Chemistry on the rate of reactions. To achieve this, we mobilised the indigenous technologies of preserving and pounding Mahangu and making Oshikundu to mediate learning of the rate of reactions. The study was guided by the broad overarching research question: How does a peer-learning community and expert community members leverage the integration of indigenous knowledge into the learning and teaching of Grade 10 Chemistry on the rate of reactions? In this study, I used two complementary paradigms, viz. the transformative research paradigm and the indigenous research paradigm. Within these paradigms, I employed a qualitative case study research design using the community of practice and participatory action research as research approaches. Five Grade 10 Chemistry teachers from three schools in the Ohangwena region were involved in this study. Data were generated through semi-structured interviews, co-analysis of curriculum documents, workshop presentations and discussions, practical demonstrations, participatory observation, lesson observation, stimulated recall interviews, and participants’ reflections. Vygotsky’s sociocultural theory and Shulman’s Pedagogical Content Knowledge (PCK) were employed as theoretical frameworks in this study. Additionally, within PCK, Mavhunga and Rollnick’s Topic-Specific Pedagogical Content Knowledge components were used as an analytical framework. I used an inductive-deductive approach to data analysis to come up with sub-themes and themes. The main finding of this study revealed that leveraging a peer-learning community and the expert community members (ECMs) empowered the Chemistry teachers involved in this study to be cultural knowledge brokers and their understanding of how to integrate IK in their teaching improved. Both their subject matter knowledge and pedagogical content knowledge improved through co-developing and enacting exemplar lessons that integrated IK from the expert community members as well as from their own environments. A main insight of this study is that Chemistry teachers should seek opportunities to create peer-learning communities that engage with expert community members who are the custodians of the cultural heritage. The study also shows that this approach will support them to become better cultural knowledge brokers and help their learners bridge the divide between school science and what they have learnt in their homes or community. , Thesis (PhD) -- Faculty of Education, Education, 2023
- Full Text:
- Date Issued: 2023-03-29
Izit? Hoe lyk hulle? Kom ons ǂXoa – A South African Khoe-San narrative
- Authors: Gabie, Sharon
- Date: 2023-03-30
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/409790 , vital:70630 , DOI 10.21504/10962/409790
- Description: The foundation of the South African narrative is framed by identity politics; a politics instituted at the intersection of race and class to exclude all people considered non-White concerning the socioeconomic and political landscape of the country. The preamble of the Freedom Charter signed in 1955 declared that the country belongs to all who live in it: Black and White people. The dominant constructivist narratives of addressing the racial dichotomy obliterate the injustice suffered by the Khoe-San people whose identity was overshadowed under the homogeneous term, Coloured people. Following the first democratic elections, at the negotiations of the Convention for a Democratic South Africa (CODESA) in 1996, Khoe-San people were once again excluded and played no significant role in deciding the future of the new South Africa. The epistemic injustice suffered by the Khoe-San people, the loss of land, language, and cultural heritage were glanced over in the new democratic dispensation. In this thesis, I hone into the identity politics and identity formation of the Khoe-San people, after 1994. The self-identifying Khoe-San people became visible to the democratic state through various forms of activism and networking across provinces foregrounding the concept of indigeneity to address issues of exclusion and marginalisation. The phenomenon of indigeneity, bestowed on Khoe-San people by the United Nations Declaration on the Rights of Indigenous People (UNDRIP) created a path for the Khoe-San people to be in conversation with state organs to address their plight of the loss of land linked to identity, language, culture, heritage, and other social ills experienced in their communities. The thesis illustrates the vagueness of Coloured identity under the Apartheid state, and the preconceived narrative that Coloured people were a privileged group; precludes and obliterates the epistemic injustice suffered by Khoe-San people. The transnational conceptualisation and global politics of indigenous peoples; the particularity of indigeneity in relation to First Nation Status, in the South African context, destabilises identity politics and the four-tier racial categorisation system used by the Apartheid state carried through by the national government under democracy. The conceptualisation of this global discourse on indigeneity brought a new consciousness in sections of the Coloured community where self-identifying Khoe-San people question their place in the democratic dispensation. , Thesis (PhD) -- Faculty of Humanities, Anthropology, 2023
- Full Text:
- Date Issued: 2023-03-30
- Authors: Gabie, Sharon
- Date: 2023-03-30
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/409790 , vital:70630 , DOI 10.21504/10962/409790
- Description: The foundation of the South African narrative is framed by identity politics; a politics instituted at the intersection of race and class to exclude all people considered non-White concerning the socioeconomic and political landscape of the country. The preamble of the Freedom Charter signed in 1955 declared that the country belongs to all who live in it: Black and White people. The dominant constructivist narratives of addressing the racial dichotomy obliterate the injustice suffered by the Khoe-San people whose identity was overshadowed under the homogeneous term, Coloured people. Following the first democratic elections, at the negotiations of the Convention for a Democratic South Africa (CODESA) in 1996, Khoe-San people were once again excluded and played no significant role in deciding the future of the new South Africa. The epistemic injustice suffered by the Khoe-San people, the loss of land, language, and cultural heritage were glanced over in the new democratic dispensation. In this thesis, I hone into the identity politics and identity formation of the Khoe-San people, after 1994. The self-identifying Khoe-San people became visible to the democratic state through various forms of activism and networking across provinces foregrounding the concept of indigeneity to address issues of exclusion and marginalisation. The phenomenon of indigeneity, bestowed on Khoe-San people by the United Nations Declaration on the Rights of Indigenous People (UNDRIP) created a path for the Khoe-San people to be in conversation with state organs to address their plight of the loss of land linked to identity, language, culture, heritage, and other social ills experienced in their communities. The thesis illustrates the vagueness of Coloured identity under the Apartheid state, and the preconceived narrative that Coloured people were a privileged group; precludes and obliterates the epistemic injustice suffered by Khoe-San people. The transnational conceptualisation and global politics of indigenous peoples; the particularity of indigeneity in relation to First Nation Status, in the South African context, destabilises identity politics and the four-tier racial categorisation system used by the Apartheid state carried through by the national government under democracy. The conceptualisation of this global discourse on indigeneity brought a new consciousness in sections of the Coloured community where self-identifying Khoe-San people question their place in the democratic dispensation. , Thesis (PhD) -- Faculty of Humanities, Anthropology, 2023
- Full Text:
- Date Issued: 2023-03-30
Revitalisation and indigenisation of the Science curriculum through drum making, drumming, music and dance
- Authors: Liveve, Angelius Kanyanga
- Date: 2022-10-14
- Subjects: Curriculum change Namibia , Science Study and teaching (Secondary) Namibia , Traditional ecological knowledge Namibia , Drum Performance , Drum making , Pedagogical content knowledge , Social learning
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405482 , vital:70175 , DOI 10.21504/10962/405482
- Description: The integration of IK is a common phenomenon in many postcolonial states, where it is viewed as a means to redress the injustices of the colonial era. It is believed that the recognition of IK in education represents an acknowledgement of diversity and other ways of knowing. In Namibia, for instance, the National Curriculum for Basic Education encourages the integration of IK in Science teaching. However, this goal is still far from being achieved because the curriculum seems to be silent on how teachers should integrate IK into their teaching. As a result, research shows that many Science teachers in Namibia seem to find it difficult to integrate IK into their science teaching because they were not properly trained to do so during both their pre-service and in-service training. This suggests that there is a dire need to empower science teachers who are implementers of the curriculum on appropriate pedagogical content knowledge on how to integrate IK into their science teaching in particular. It is against this backdrop that this interventionist study sought to explore how to mobilise the indigenous technology of drum making, drumming, music and dance for cultural revitalisation and indigenisation of the science curriculum. The study is underpinned by an interpretivist paradigm and augmented with an indigenous research paradigm. The interpretivist paradigm enabled me to understand the teachers’ perspectives in their contexts. On the other hand, within the indigenous research paradigm, I used the Ubuntu perspective which afforded each of us an opportunity to understand each other’s ways of knowing, doing and being. Within these two complementary paradigms, a qualitative case study approach was employed. The case study was in the form of intervention with six Grade 10 Physics teachers from three senior secondary schools in the Kavango West Region in Namibia. Moreover, a critical friend who was a lecturer at the university and expert community members of the Unongo Cultural Youth Group who are the custodians of the cultural heritage. Data were generated using semi-structured interviews, workshop discussions (audio-recorded), observations (participatory and lesson observations), stimulated recall interviews as well as journal reflections. Vygotsky’s Socio-cultural Theory, Ogunniyi’s Contiguity Argumentation Theory and Mavhunga and Rollnick’s Topic-specific Pedagogical Content Knowledge were used as the theoretical lenses in this study. The data gathered were analysed thematically and then categorised into sub-themes and themes. The findings of the study revealed that tapping into the cultural heritage of community members through giving them a voice has great potential to revitalise and indigenise the science curriculum. It also emerged in this study that storytelling is a potential instructional strategy to make science accessible and relevant to learners. The use of the indigenous technology of drum making, drumming, music and dance contributed to the Physics teachers’ agency and empowered them to co-develop their learning and teaching support materials in the form of exemplar lesson plans that integrated IK. Moreover, their pedagogical content knowledge was enhanced through enacting such exemplar lessons and thereafter reflecting on them. The study thus recommends that those in academia should promote the use of indigenous technologies as hubs for mediating the learning of science concepts. It also recommends that learners should be taken out of their science classrooms into the community to learn IK and wisdom from expert community members, something which could assist them in understanding the science taught at school. This might also benefit teachers in effectively implementing the integration of IK in schools and thereby use learners’ cultural heritage as a starting point to enrich meaningful and authentic learning. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Liveve, Angelius Kanyanga
- Date: 2022-10-14
- Subjects: Curriculum change Namibia , Science Study and teaching (Secondary) Namibia , Traditional ecological knowledge Namibia , Drum Performance , Drum making , Pedagogical content knowledge , Social learning
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405482 , vital:70175 , DOI 10.21504/10962/405482
- Description: The integration of IK is a common phenomenon in many postcolonial states, where it is viewed as a means to redress the injustices of the colonial era. It is believed that the recognition of IK in education represents an acknowledgement of diversity and other ways of knowing. In Namibia, for instance, the National Curriculum for Basic Education encourages the integration of IK in Science teaching. However, this goal is still far from being achieved because the curriculum seems to be silent on how teachers should integrate IK into their teaching. As a result, research shows that many Science teachers in Namibia seem to find it difficult to integrate IK into their science teaching because they were not properly trained to do so during both their pre-service and in-service training. This suggests that there is a dire need to empower science teachers who are implementers of the curriculum on appropriate pedagogical content knowledge on how to integrate IK into their science teaching in particular. It is against this backdrop that this interventionist study sought to explore how to mobilise the indigenous technology of drum making, drumming, music and dance for cultural revitalisation and indigenisation of the science curriculum. The study is underpinned by an interpretivist paradigm and augmented with an indigenous research paradigm. The interpretivist paradigm enabled me to understand the teachers’ perspectives in their contexts. On the other hand, within the indigenous research paradigm, I used the Ubuntu perspective which afforded each of us an opportunity to understand each other’s ways of knowing, doing and being. Within these two complementary paradigms, a qualitative case study approach was employed. The case study was in the form of intervention with six Grade 10 Physics teachers from three senior secondary schools in the Kavango West Region in Namibia. Moreover, a critical friend who was a lecturer at the university and expert community members of the Unongo Cultural Youth Group who are the custodians of the cultural heritage. Data were generated using semi-structured interviews, workshop discussions (audio-recorded), observations (participatory and lesson observations), stimulated recall interviews as well as journal reflections. Vygotsky’s Socio-cultural Theory, Ogunniyi’s Contiguity Argumentation Theory and Mavhunga and Rollnick’s Topic-specific Pedagogical Content Knowledge were used as the theoretical lenses in this study. The data gathered were analysed thematically and then categorised into sub-themes and themes. The findings of the study revealed that tapping into the cultural heritage of community members through giving them a voice has great potential to revitalise and indigenise the science curriculum. It also emerged in this study that storytelling is a potential instructional strategy to make science accessible and relevant to learners. The use of the indigenous technology of drum making, drumming, music and dance contributed to the Physics teachers’ agency and empowered them to co-develop their learning and teaching support materials in the form of exemplar lesson plans that integrated IK. Moreover, their pedagogical content knowledge was enhanced through enacting such exemplar lessons and thereafter reflecting on them. The study thus recommends that those in academia should promote the use of indigenous technologies as hubs for mediating the learning of science concepts. It also recommends that learners should be taken out of their science classrooms into the community to learn IK and wisdom from expert community members, something which could assist them in understanding the science taught at school. This might also benefit teachers in effectively implementing the integration of IK in schools and thereby use learners’ cultural heritage as a starting point to enrich meaningful and authentic learning. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-10-14