Action Research reflecting the process of a collaborative, multi-theoretical group intervention with foster parents of children affected by childhood trauma
- Authors: Cahill, Susan Mary
- Date: 2023-10-13
- Subjects: Foster parents Ireland , Foster home care Ireland , Attachment theory , Psychic trauma in children , Group psychotherapy , Parenting stress
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432297 , vital:72859 , DOI 10.21504/10962/432297
- Description: Children are received into the Care of the State in the Republic of Ireland due to chronic or acute maltreatment in their families of origin. Maltreatment may include neglect; physical, sexual, or emotional abuse; exposure to domestic violence; or a combination of these. Resulting emotional and behavioural consequences may be challenging to foster parents who might experience stress, secondary trauma, compassion fatigue or burnout, which along with the child’s emotional and behavioural difficulties can result in placement breakdown. After reviewing the literature on fostering internationally and in Ireland, this study sought to determine the types and level of stress in a sample of foster parents and the types of challenging emotional and behavioural difficulties of their fostered children. Results revealed that foster parents found fostering stressful; factors included biological parents; organisational issues; and the child’s behaviour. According to the foster parents, nearly 60% of the foster children in this sample were showing high levels of emotional and behavioural distress. These difficulties differed according to age and gender. Adolescent Girls and Young Boys (5 – 11 years) were reported as having the most difficulties, including symptoms of behavioural and Conduct Disorder (CD). Symptoms associated with CD were reported in at least 40% of every age and gender category of children over five years. Further, this study outlines the development, facilitation and outcomes of a small group psychoeducational-reflective foster parenting Course, involving six separate groups of parents (n=38) each meeting for eight sessions. In this Course, foster children were conceptualised from a bio-psycho-social-ecological viewpoint, utilising theoretical concepts from Prenatal Development, Attachment and Trauma, pertaining to vulnerable children to illustrate the cumulative effects of adversities. Time for discussion and reflection on the material was structured into the Course. This combination of knowledge, practical skills, reflection and support for parents aimed to promote healing relationship-based practices for the child within their foster home. This multi-faceted study was grounded in Community Psychology, using mixed methods to gather data during action research processes, to reflect the different components of an action cycle. Ideas and modifications to the Course based on feedback from the foster parent participants’ experiences have been included. It is recommended that the Course be provided to other foster parents and audiences such as social workers, teachers and solicitors. Furthermore, suggestions are made regarding assessment, diagnosis and interventions for foster children and parents, based on a multidisciplinary consultancy model. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Cahill, Susan Mary
- Date: 2023-10-13
- Subjects: Foster parents Ireland , Foster home care Ireland , Attachment theory , Psychic trauma in children , Group psychotherapy , Parenting stress
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432297 , vital:72859 , DOI 10.21504/10962/432297
- Description: Children are received into the Care of the State in the Republic of Ireland due to chronic or acute maltreatment in their families of origin. Maltreatment may include neglect; physical, sexual, or emotional abuse; exposure to domestic violence; or a combination of these. Resulting emotional and behavioural consequences may be challenging to foster parents who might experience stress, secondary trauma, compassion fatigue or burnout, which along with the child’s emotional and behavioural difficulties can result in placement breakdown. After reviewing the literature on fostering internationally and in Ireland, this study sought to determine the types and level of stress in a sample of foster parents and the types of challenging emotional and behavioural difficulties of their fostered children. Results revealed that foster parents found fostering stressful; factors included biological parents; organisational issues; and the child’s behaviour. According to the foster parents, nearly 60% of the foster children in this sample were showing high levels of emotional and behavioural distress. These difficulties differed according to age and gender. Adolescent Girls and Young Boys (5 – 11 years) were reported as having the most difficulties, including symptoms of behavioural and Conduct Disorder (CD). Symptoms associated with CD were reported in at least 40% of every age and gender category of children over five years. Further, this study outlines the development, facilitation and outcomes of a small group psychoeducational-reflective foster parenting Course, involving six separate groups of parents (n=38) each meeting for eight sessions. In this Course, foster children were conceptualised from a bio-psycho-social-ecological viewpoint, utilising theoretical concepts from Prenatal Development, Attachment and Trauma, pertaining to vulnerable children to illustrate the cumulative effects of adversities. Time for discussion and reflection on the material was structured into the Course. This combination of knowledge, practical skills, reflection and support for parents aimed to promote healing relationship-based practices for the child within their foster home. This multi-faceted study was grounded in Community Psychology, using mixed methods to gather data during action research processes, to reflect the different components of an action cycle. Ideas and modifications to the Course based on feedback from the foster parent participants’ experiences have been included. It is recommended that the Course be provided to other foster parents and audiences such as social workers, teachers and solicitors. Furthermore, suggestions are made regarding assessment, diagnosis and interventions for foster children and parents, based on a multidisciplinary consultancy model. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Date Issued: 2023-10-13
African population prevalent genetic variations of dihydropyrimidine dehydrogenase as the 5-flourouracil cancer drug metabolizing enzyme: computational approaches towards pharmacogenomics studies
- Authors: Tendwa, Maureen Bilinga
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432263 , vital:72856 , DOI 10.21504/10962/432270
- Description: In an era of newly emerging cases of non-communicable diseases such as cancer, research is vital for both the medical and economic well-being of humanity. Pharmacogenomics has laidthegroundworkfor the identification of potential genes in cancer progression and treatment outcome investigations. Researchers are increasingly discovering heterogeneity in the efficacy and toxicity responses of drugmetabolizing enzymes (DMEs) in diverse patient populations receiving anti-cancer therapy. DMEs comprise of Phase I (Cytochrome P450s) and Phase II (glutathione-S-transferases (GSTs), UDP-glucuronosyltransferases (UGTs), and dihydropyrimidine dehydrogenases (DPD)enzymes. The main cause of disparity in DME treatment outcomes is genetic variation,which causes missense mutations leading to structural and kinetic properties of the enzyme. These modifications have a deleterious impact on the pharmacodynamics and pharmacokinetics of drugs through multiple mechanisms. Presently, most cancer medicines are manufacturedin developed countries based on the genetic background of non-African subpopulations. Thus, these drugs may not be optimally effective or can cause adverse side effects. Even though heterogeneity in toxicity and efficacy of these drugs has been observed in African descent, the basis of this population variance remains partially understood. For instance,a deficiencyof DPD, the first-rate limiting metabolizing enzyme in the pyrimidinepathway, causes severe toxicity when exposed to 5-fluorouracil (5-FU) chemotherapy. However, minimum studies have been conducted to unravel itsmolecular mechanismwhich may unravel the observed drug treatment outcomes.The aim of this pharmacogenomics study was to determine the underlying mechanism by which DPD missense mutations, which are associated with an African ancestry subpopulation, provoke dysfunctional 5-FU metabolism, resulting in drug toxicity. This knowledge will be critical in designing drug modulators to aid in the restoration of DPD function, a hallmark of precision medicine. Therefore, in the first part of the research we identified and reviewed the general role of Phase I and Phase II cancer drug metabolizing enzymes. We then used World Health Organization (WHO) essential medicine and drug.com to authenticate the usage of 5-FU as an anti-cancer treatment agent. The 3D structure and chemical structure of the agent was then downloaded from the Drug bank. Subsequently, Human Mutation Analysis - Variant Analysis PORtal (HUMA) and Mendelian Inheritance in Man (OMIM) were used to obtain data on DPD non-synonymous genetic variants. Additionally, the aggregate information of DPD missense mutations and their relation to human health were extracted from ClinVar and Pharmacogenomics Knowledge Base (PharmKGB). This information, along with additional data from single nucleotide polymorphisms (dbSNP), 1000 Genomes Project and Exome Sequencing Project (ESP MAF) considering variants classified based on their minor allele frequency (MAF) of 0.001, as well as research articles, consolidated information on missense mutations associated with African subpopulations. Finally, the wild type (WT) and detected mutation sequences were obtained from the Universal Protein Resources database (UniProt). However, because the 3D structure of human DPD was missing, the dimeric wild type (WT) human 3-dimensional (3D) structure was modeled via MODELLER using the pig’s structure as a template. PRIMO, HHpred, and the Protein Data Bank (PDB) were all used to locate the suitable template. As a result, six clinical (C29R, M166V, Y186C, S534N, I543V, and D949V) and thirteen non-clinical (S201R, K259E, D342N, D432N, S492L, R592Q, A664S, G674D, A721T, V732G, T768K, R886C, and L993R) mutations were discovered. Using AMBER tools, we then determined accurate force field parameters for each monomer of DPD protein's Fe2+ centers. Following the creation of each mutation model structure in Discovery Studio, the resulting AMBER force field parameters were inferred. For each model structure, a drug free (inactive/open-conformation) and drug bound (active/closed-conformation) model structure was created (WT and mutations). The model structures were validated using the consensus of three validation programs, namely ERRAT, PROCHECK, and ProSA. Similarly, the impact on structural functionalities was predicted by consensus from Variant Analysis Porta (VAPOR) web server, which include three support vector machines (SVM)-based tools; PhD-SNP, MUpro, and I-Mutation. After protonation in the H++ web server, the six clinical and thirteen non-clinical (six active site and seven non-active site) mutations identified were then exposed to 600 ns molecular dynamic (MD) simulation. The non-clinical data was divided into two categories to better understand the impact of the mutation based on its position in the protein: six catalytic-domain (R592Q, A664S, G674D, A721T, V732G, and T768K) and seven remote (S201R, K259E, D342N, D432N, S492L, R886C, and L993R) missense mutations. The post-MD analysis was done using the typical existing computational global investigations [RMSD, all versus all RMSD, RMSF, RG, hydrogen bonds (H-bonds) and dynamic cross correlation (DCC)]. In addition, we used in silico tools newly developed within the Research Unit in Bioinformatics (RUBI) group, such as comparative essential dynamics (ED)-principal component analysis and dynamic residue network (DRN) multi-metric [betweenness centrality (BC), closeness centrality (CC), degree of centrality (DC), eigen-centrality (EC) and Katz centrality (KC)] analysis algorithms. From the analysis, it was observed that the loop regions of the mutation proteins had increased loop flexibility, particularly around the catalytic loop, which could account for the enhanced asymmetric behavior of the mutation’s monomers compared to the WT. Notably, the A664S mutant showed relatively lower fluctuations, deviating from the observed heightened flexibility in other mutants. A general decrease in hydrogen bonds was observed in the 5-FU binding environment of the mutations compared to the WT. In particular, 5-FU contact analysis of the WT versus the mutation revealed a reduction in contact between core 5-FU binding residues and catalytic residues Cys671 and Ser670, which form hydrogen bonds that initiate DPD catalytic action. Additionally, BC was used to quantify the importance of a protein residue based on how often it acted as a bridge along the shortest paths between other residues. It reflected the potential control or influence a residue may have over communication between different parts of a protein structure. DC assesses the number of connections or interactions a residue had with other residues in the protein, indicating its overall connectivity within the structure. In both drug free and drug bound state, DPD data from the active site hubs' BC and DC revealed a dimeric asymmetric communication pathway per monomer involving a cluster of newly introduced hubs ensemble along the oxidoreduction conduit from NADPH to 5-FU. The two BC communication pathways were located more on the interior of the oxidoreduction conduit, while the two DC communication pathways were located on the exterior. In both cases, one pathway dominated the other. Partially lost function reported in mutation systems could be credited to the compensation communication response to the catalytic site via the least compromised routes. Similar patterns were observed in allosteric communication pathways to the active site induced by remote mutations. Mutations may have destabilized the active-loop and 5-FU binding environment, resulting in a compensatory mechanism seen by the addition of new hubs to the communication network. Surprisingly, EC hubs in the WT were found within the catalytic site domain, indicating that the region is important in 5-FU metabolism. EC measured the importance of a residue by considering both its own degree of connectivity and the degrees of connectivity with its neighboring residues, highlighting its significance in information flow and communication. Herein, EC hubs in mutant systems were found to lose this importance, with active site domain mutations suffering the most. This could explain why non-clinical catalytic domain mutations R592Q, A664S, and G674D, as well as clinical catalytic domain mutations S534N and I543V, experienced drug exit in one of their monomers during simulation. In contrast, there was no 5-FU exit in the non-clinical remote domain. Additionally, aside from the active site, KC hubs were also found around the cofactors, indicating that these components were equally important in DPD overall function. KC combines the concepts of both degree centrality and eigen-centrality, it incorporated both direct and indirect interactions to evaluate the importance of a residue, assigning higher centrality to residues that have connections to other highly central residues. Hence, providing a more comprehensive measure of influence within the protein network. More importantly, CC is known to measure how efficiently a residue can interact with other residues in the protein, considering the shortest path lengths. It indicates the proximity of a residue to others, suggesting its potential for information transfer or functional integration. CC revealed that the majority of persistent hubs were found within the protein-cores known as cold-spots. Overall, this study highlighted the communication pathways triggered by active site domain mutations, as well as the allosteric communication pathways triggered by each remote mutation in both drug free and drug bound states of the DPD enzyme. Both clinical and non-clinical mutations revealed each protein's adaptive compensation mechanism, which results in partial function loss. In each case, the communication network of the different monomers changed from inactive to activated DPD protein. Cold-spot areas were discovered to contain key persistent residues involved in protein function and stability. These areas have been proposed as potential targets for new or repurposed pharmacological modulators that can restore enzyme function. In the pursuit of precision medicine, it also lays the groundwork for detecting and explaining the molecular mechanisms of other drug metabolizing enzymes related to the African-descent subpopulation. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Tendwa, Maureen Bilinga
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432263 , vital:72856 , DOI 10.21504/10962/432270
- Description: In an era of newly emerging cases of non-communicable diseases such as cancer, research is vital for both the medical and economic well-being of humanity. Pharmacogenomics has laidthegroundworkfor the identification of potential genes in cancer progression and treatment outcome investigations. Researchers are increasingly discovering heterogeneity in the efficacy and toxicity responses of drugmetabolizing enzymes (DMEs) in diverse patient populations receiving anti-cancer therapy. DMEs comprise of Phase I (Cytochrome P450s) and Phase II (glutathione-S-transferases (GSTs), UDP-glucuronosyltransferases (UGTs), and dihydropyrimidine dehydrogenases (DPD)enzymes. The main cause of disparity in DME treatment outcomes is genetic variation,which causes missense mutations leading to structural and kinetic properties of the enzyme. These modifications have a deleterious impact on the pharmacodynamics and pharmacokinetics of drugs through multiple mechanisms. Presently, most cancer medicines are manufacturedin developed countries based on the genetic background of non-African subpopulations. Thus, these drugs may not be optimally effective or can cause adverse side effects. Even though heterogeneity in toxicity and efficacy of these drugs has been observed in African descent, the basis of this population variance remains partially understood. For instance,a deficiencyof DPD, the first-rate limiting metabolizing enzyme in the pyrimidinepathway, causes severe toxicity when exposed to 5-fluorouracil (5-FU) chemotherapy. However, minimum studies have been conducted to unravel itsmolecular mechanismwhich may unravel the observed drug treatment outcomes.The aim of this pharmacogenomics study was to determine the underlying mechanism by which DPD missense mutations, which are associated with an African ancestry subpopulation, provoke dysfunctional 5-FU metabolism, resulting in drug toxicity. This knowledge will be critical in designing drug modulators to aid in the restoration of DPD function, a hallmark of precision medicine. Therefore, in the first part of the research we identified and reviewed the general role of Phase I and Phase II cancer drug metabolizing enzymes. We then used World Health Organization (WHO) essential medicine and drug.com to authenticate the usage of 5-FU as an anti-cancer treatment agent. The 3D structure and chemical structure of the agent was then downloaded from the Drug bank. Subsequently, Human Mutation Analysis - Variant Analysis PORtal (HUMA) and Mendelian Inheritance in Man (OMIM) were used to obtain data on DPD non-synonymous genetic variants. Additionally, the aggregate information of DPD missense mutations and their relation to human health were extracted from ClinVar and Pharmacogenomics Knowledge Base (PharmKGB). This information, along with additional data from single nucleotide polymorphisms (dbSNP), 1000 Genomes Project and Exome Sequencing Project (ESP MAF) considering variants classified based on their minor allele frequency (MAF) of 0.001, as well as research articles, consolidated information on missense mutations associated with African subpopulations. Finally, the wild type (WT) and detected mutation sequences were obtained from the Universal Protein Resources database (UniProt). However, because the 3D structure of human DPD was missing, the dimeric wild type (WT) human 3-dimensional (3D) structure was modeled via MODELLER using the pig’s structure as a template. PRIMO, HHpred, and the Protein Data Bank (PDB) were all used to locate the suitable template. As a result, six clinical (C29R, M166V, Y186C, S534N, I543V, and D949V) and thirteen non-clinical (S201R, K259E, D342N, D432N, S492L, R592Q, A664S, G674D, A721T, V732G, T768K, R886C, and L993R) mutations were discovered. Using AMBER tools, we then determined accurate force field parameters for each monomer of DPD protein's Fe2+ centers. Following the creation of each mutation model structure in Discovery Studio, the resulting AMBER force field parameters were inferred. For each model structure, a drug free (inactive/open-conformation) and drug bound (active/closed-conformation) model structure was created (WT and mutations). The model structures were validated using the consensus of three validation programs, namely ERRAT, PROCHECK, and ProSA. Similarly, the impact on structural functionalities was predicted by consensus from Variant Analysis Porta (VAPOR) web server, which include three support vector machines (SVM)-based tools; PhD-SNP, MUpro, and I-Mutation. After protonation in the H++ web server, the six clinical and thirteen non-clinical (six active site and seven non-active site) mutations identified were then exposed to 600 ns molecular dynamic (MD) simulation. The non-clinical data was divided into two categories to better understand the impact of the mutation based on its position in the protein: six catalytic-domain (R592Q, A664S, G674D, A721T, V732G, and T768K) and seven remote (S201R, K259E, D342N, D432N, S492L, R886C, and L993R) missense mutations. The post-MD analysis was done using the typical existing computational global investigations [RMSD, all versus all RMSD, RMSF, RG, hydrogen bonds (H-bonds) and dynamic cross correlation (DCC)]. In addition, we used in silico tools newly developed within the Research Unit in Bioinformatics (RUBI) group, such as comparative essential dynamics (ED)-principal component analysis and dynamic residue network (DRN) multi-metric [betweenness centrality (BC), closeness centrality (CC), degree of centrality (DC), eigen-centrality (EC) and Katz centrality (KC)] analysis algorithms. From the analysis, it was observed that the loop regions of the mutation proteins had increased loop flexibility, particularly around the catalytic loop, which could account for the enhanced asymmetric behavior of the mutation’s monomers compared to the WT. Notably, the A664S mutant showed relatively lower fluctuations, deviating from the observed heightened flexibility in other mutants. A general decrease in hydrogen bonds was observed in the 5-FU binding environment of the mutations compared to the WT. In particular, 5-FU contact analysis of the WT versus the mutation revealed a reduction in contact between core 5-FU binding residues and catalytic residues Cys671 and Ser670, which form hydrogen bonds that initiate DPD catalytic action. Additionally, BC was used to quantify the importance of a protein residue based on how often it acted as a bridge along the shortest paths between other residues. It reflected the potential control or influence a residue may have over communication between different parts of a protein structure. DC assesses the number of connections or interactions a residue had with other residues in the protein, indicating its overall connectivity within the structure. In both drug free and drug bound state, DPD data from the active site hubs' BC and DC revealed a dimeric asymmetric communication pathway per monomer involving a cluster of newly introduced hubs ensemble along the oxidoreduction conduit from NADPH to 5-FU. The two BC communication pathways were located more on the interior of the oxidoreduction conduit, while the two DC communication pathways were located on the exterior. In both cases, one pathway dominated the other. Partially lost function reported in mutation systems could be credited to the compensation communication response to the catalytic site via the least compromised routes. Similar patterns were observed in allosteric communication pathways to the active site induced by remote mutations. Mutations may have destabilized the active-loop and 5-FU binding environment, resulting in a compensatory mechanism seen by the addition of new hubs to the communication network. Surprisingly, EC hubs in the WT were found within the catalytic site domain, indicating that the region is important in 5-FU metabolism. EC measured the importance of a residue by considering both its own degree of connectivity and the degrees of connectivity with its neighboring residues, highlighting its significance in information flow and communication. Herein, EC hubs in mutant systems were found to lose this importance, with active site domain mutations suffering the most. This could explain why non-clinical catalytic domain mutations R592Q, A664S, and G674D, as well as clinical catalytic domain mutations S534N and I543V, experienced drug exit in one of their monomers during simulation. In contrast, there was no 5-FU exit in the non-clinical remote domain. Additionally, aside from the active site, KC hubs were also found around the cofactors, indicating that these components were equally important in DPD overall function. KC combines the concepts of both degree centrality and eigen-centrality, it incorporated both direct and indirect interactions to evaluate the importance of a residue, assigning higher centrality to residues that have connections to other highly central residues. Hence, providing a more comprehensive measure of influence within the protein network. More importantly, CC is known to measure how efficiently a residue can interact with other residues in the protein, considering the shortest path lengths. It indicates the proximity of a residue to others, suggesting its potential for information transfer or functional integration. CC revealed that the majority of persistent hubs were found within the protein-cores known as cold-spots. Overall, this study highlighted the communication pathways triggered by active site domain mutations, as well as the allosteric communication pathways triggered by each remote mutation in both drug free and drug bound states of the DPD enzyme. Both clinical and non-clinical mutations revealed each protein's adaptive compensation mechanism, which results in partial function loss. In each case, the communication network of the different monomers changed from inactive to activated DPD protein. Cold-spot areas were discovered to contain key persistent residues involved in protein function and stability. These areas have been proposed as potential targets for new or repurposed pharmacological modulators that can restore enzyme function. In the pursuit of precision medicine, it also lays the groundwork for detecting and explaining the molecular mechanisms of other drug metabolizing enzymes related to the African-descent subpopulation. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
An analysis of power relations, affiliation and individuation in selected coup, secession, and inaugural speeches of Nigerian leaders, 1960-2015
- Authors: Unegbu, Osondu Chukwuemeka
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432399 , vital:72867 , DOI 10.21504/10962/432399
- Description: This study examines the positioning of Zimbabwe and the United Kingdom (UK) in the language of news articles about diplomatic relations between the two countries published in two prominent Zimbabwean newspapers, The Herald and The Standard, between 2016 and 2020, using Systemic Functional Linguistics (SFL) and Legitimation Code Theory (LCT). Zimbabwe's present diplomatic discourses are a product of its colonial and post-independence history. This thesis places The Herald and The Standard within the larger context of the Zimbabwean media landscape as a state-owned and a privately owned newspaper, respectively. It contends that the two newspapers influence the positioning of Zimbabwe and the United Kingdom in public spheres where readers engage with the news concerning diplomatic ties. The research begins with a corpus-based examination of 42 news articles published between 2016 and 2020 in The Herald and The Standard. The investigation identified several angles through which Zimbabwe and the UK are positioned in the coverage. Zimbabwe is positioned through reference to its reform agenda, intentions for free and fair elections, and its diplomatic re-engagement drive. The UK is positioned as a source of development funding and new trade agreements, while improved diplomatic relations and the removal of restrictive measures against Zimbabwe are anticipated. Fine-grained analysis was conducted on four articles, two from each newspaper, selected to reflect the trends found in the corpus analysis. The fine-grained analyses showed how linguistic resources contributed to the positioning of the UK and Zimbabwe. Complementary analyses of these articles were conducted using LCT and SFL to describe how readers' knowledge of diplomatic relations is built using language in The Herald and The Standard. The study used the concepts of constellations and cosmologies from LCT to demonstrate how diplomatic knowledge is built in these news articles. In the articles, the constellations are related to policies such as Zimbabwe's reform agenda, people (diplomats and government officials) and moral judgments. Both newspapers contain both positive and negative positioning of Zimbabwe and the UK. However, The Standard is generally critical of removing the UK's sanctions on Zimbabwe and of the Zimbabwean government's reform agenda. Meanwhile, The Herald justifies Zimbabwe's Fast-track Land Reform Programme as resulting from Britain's refusal to fund a land redistribution programme as per the 1979 Lancaster House Agreement. The use of SFL's Appraisal framework helps to examine the linguistic resources used by The Herald and The Standard to describe the positioning of the two countries in relation to each other. Lexical strings help to establish diplomatic positioning in the news articles. These couple with Appraisal to accomplish individuation and affiliation. Affect and Judgement resources revealed the decisions taken by the UK to solve the conflict by encouraging the implementation of a reform agenda by Zimbabwe. Negative evaluation is consistently used to disalign with sanctions. The emerging patterns in the data show that diplomats representing the UK affiliate with Zimbabwe's stated economic and political reforms, and the government of Zimbabwe affiliates with the new trade agreement between Zimbabwe and the UK. At the same time, the UK diplomats individuate away from human rights abuses and the Fast-track Land Reform Programme. Affiliation strengthens confidence in diplomatic ties between Zimbabwe and the UK because the emphasis is placed on restoring them despite the conditions attached. The Herald and The Standard position Zimbabwe as a reformed country ready to implement policies to improve citizens' lives and as a country violating human rights and the rule of law. They position the UK as asserting power over Zimbabwe, willing to resolve the crisis through its foreign policy, and credited for assisting Zimbabwe. This strengthens re-engagement in diplomatic relations and commercial trade between the UK and Zimbabwe. In light of these findings, Zimbabweans are encouraged to cultivate an awareness that enables them to reflect on the challenges associated with diplomatic discourses and the implications for critically analysing the re-engagement initiative. They can promote re-engagement by being cognisant of specific values portrayed in The Herald and The Standard and challenging these values in the light of policy transformation to revive the relations between the two countries. The re-engagement process requires a transformation in Zimbabwe's modus operandi to improve the country's positioning in the diplomatic relations between it and the UK. , Thesis (PhD) -- Faculty of Humanities, Linguistics and Applied Language Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Unegbu, Osondu Chukwuemeka
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432399 , vital:72867 , DOI 10.21504/10962/432399
- Description: This study examines the positioning of Zimbabwe and the United Kingdom (UK) in the language of news articles about diplomatic relations between the two countries published in two prominent Zimbabwean newspapers, The Herald and The Standard, between 2016 and 2020, using Systemic Functional Linguistics (SFL) and Legitimation Code Theory (LCT). Zimbabwe's present diplomatic discourses are a product of its colonial and post-independence history. This thesis places The Herald and The Standard within the larger context of the Zimbabwean media landscape as a state-owned and a privately owned newspaper, respectively. It contends that the two newspapers influence the positioning of Zimbabwe and the United Kingdom in public spheres where readers engage with the news concerning diplomatic ties. The research begins with a corpus-based examination of 42 news articles published between 2016 and 2020 in The Herald and The Standard. The investigation identified several angles through which Zimbabwe and the UK are positioned in the coverage. Zimbabwe is positioned through reference to its reform agenda, intentions for free and fair elections, and its diplomatic re-engagement drive. The UK is positioned as a source of development funding and new trade agreements, while improved diplomatic relations and the removal of restrictive measures against Zimbabwe are anticipated. Fine-grained analysis was conducted on four articles, two from each newspaper, selected to reflect the trends found in the corpus analysis. The fine-grained analyses showed how linguistic resources contributed to the positioning of the UK and Zimbabwe. Complementary analyses of these articles were conducted using LCT and SFL to describe how readers' knowledge of diplomatic relations is built using language in The Herald and The Standard. The study used the concepts of constellations and cosmologies from LCT to demonstrate how diplomatic knowledge is built in these news articles. In the articles, the constellations are related to policies such as Zimbabwe's reform agenda, people (diplomats and government officials) and moral judgments. Both newspapers contain both positive and negative positioning of Zimbabwe and the UK. However, The Standard is generally critical of removing the UK's sanctions on Zimbabwe and of the Zimbabwean government's reform agenda. Meanwhile, The Herald justifies Zimbabwe's Fast-track Land Reform Programme as resulting from Britain's refusal to fund a land redistribution programme as per the 1979 Lancaster House Agreement. The use of SFL's Appraisal framework helps to examine the linguistic resources used by The Herald and The Standard to describe the positioning of the two countries in relation to each other. Lexical strings help to establish diplomatic positioning in the news articles. These couple with Appraisal to accomplish individuation and affiliation. Affect and Judgement resources revealed the decisions taken by the UK to solve the conflict by encouraging the implementation of a reform agenda by Zimbabwe. Negative evaluation is consistently used to disalign with sanctions. The emerging patterns in the data show that diplomats representing the UK affiliate with Zimbabwe's stated economic and political reforms, and the government of Zimbabwe affiliates with the new trade agreement between Zimbabwe and the UK. At the same time, the UK diplomats individuate away from human rights abuses and the Fast-track Land Reform Programme. Affiliation strengthens confidence in diplomatic ties between Zimbabwe and the UK because the emphasis is placed on restoring them despite the conditions attached. The Herald and The Standard position Zimbabwe as a reformed country ready to implement policies to improve citizens' lives and as a country violating human rights and the rule of law. They position the UK as asserting power over Zimbabwe, willing to resolve the crisis through its foreign policy, and credited for assisting Zimbabwe. This strengthens re-engagement in diplomatic relations and commercial trade between the UK and Zimbabwe. In light of these findings, Zimbabweans are encouraged to cultivate an awareness that enables them to reflect on the challenges associated with diplomatic discourses and the implications for critically analysing the re-engagement initiative. They can promote re-engagement by being cognisant of specific values portrayed in The Herald and The Standard and challenging these values in the light of policy transformation to revive the relations between the two countries. The re-engagement process requires a transformation in Zimbabwe's modus operandi to improve the country's positioning in the diplomatic relations between it and the UK. , Thesis (PhD) -- Faculty of Humanities, Linguistics and Applied Language Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
An examination of the use and value of support systems for people living with HIV/AIDS in Makhanda
- Authors: Gorham, Catherine Margaret
- Date: 2023-10-13
- Subjects: HIV-positive persons South Africa Makhanda , AIDS (Disease) Patients South Africa Makhanda , Social networks , Diseases Social aspects , Health services accessibility , Narrative
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432411 , vital:72868 , DOI 10.21504/10962/432411
- Description: Through the experiences of five people, this study asks how support systems develop, are used and are valued for those faced with the everyday challenges of living with HIV. Additional evidence is found in accounts from those identified as essential sources of support. These are primarily friends, sometimes family. This perspective is rounded out by insights gathered from those working in local organisations and in the analysis of services offered by the state. The three women and two men at the centre of this study live in Makhanda in the Eastern Cape, South Africa. Makhanda (formerly Grahamstown) is characterised by extremes of poverty and wealth, reflected in low employment, expanding informal and low-income settlement areas but also in a high level of community activism and access to resources. Each of the five tested positive for HIV variously between 1998 and 2008. These years were pivotal in the development of the local and national epidemic. The rapid expansion of infection rates, contestation over forms of and access to treatment, followed by emphasis of a biomedical response, in equal measure bracket and cut across their experiences. To this point, research is less concerned with what individual experiences say about living through the HIV/AIDS epidemic. Preoccupations lie more generally with macro- or micro-level factors, with behaviour change, managing risk and so public health – not the processes linking individual circumstances and choices to opportunities and outcomes described by individual, community and structural, socio-economic contexts. Personal accounts and observations of a developing, community-based, local response to an unfolding epidemic are therefore considered against the analysis of available medical and nonmedical resources. This enables identification and investigation of social processes operating between proximal and distal conditions, determining possibilities for access to support. The focus of this study thus falls to the interrelations of structure, agency and action. It contributes to an empirical and theoretical understanding of what “support” is, what “coping” means and what unfolds where diagnosis with HIV disrupts and challenges existing ways of coping and forms of support. The accounts gathered for this study offer an “insider” perspective, focused on what follows from testing positive to identifying what resources hold significance. Connections between individual, community and society, through psycho-social, local and macro-level processes are explored. Along with the empirical study of individual accounts, the thesis offers a theoretical framework that uses a grounded-theory approach in conjunction with the tools of narrative analysis. These are critically adapted from a sociology of illness studies. Ideas of risk and response, of material and social capital, of the nature of HIV/AIDS as an experience that is inclusive of both chronic, everyday challenge and critical, life-threatening crisis disrupting a sense of time, biography and self, are brought together in the analysis. In this way the understanding of what support means, how it develops and is used (systematically or not), and of the links operating between structural and social conditions, individual agency and action, can be developed. What the thesis finds is that, beyond the medical system of hospitals and clinics, there is surprisingly little use of available resources. There is thus an absence of any systematic support for those faced with the physical, psychological, social and material impacts of HIV/AIDS. Given the nature of personal circumstances, embedded as they are within local conditions that reflect structural constraints of the broader economy and society, this should not be surprising. A system of support exists in only the most limited definition. Against this, what is novel in these findings is the role that psycho-social processes play in negotiating these conditions and how this works, determining what unfolds. A key finding is that it is more through chance than choice that people do find conventional forms of support. The reasons for this have to do not only with limitations to state and institutional capacity, but also with the impact on individuals of perceptions of themselves shaped by the impact of the epidemic and also the past. The result is that under the burden of HIV/AIDS, in the context of extreme inequalities and the absence of an adequate response from the state, already invisible individuals who do not “count” run the risk of becoming doubly invisible. It is through a process of personal adaptation in which shifts in identity and a sense of self are key that they must find their own way. This involves re-conceptualisations of identity, a sense of self and place in the world. The focus on five people and the community in which they live is a limit to the scope of study Yet it is this focus which allows for a new understanding of the social processes involved, and so the links operating between individuals and society. This is of significance beyond the study of HIV/AIDS alone, contributing to the broader sociological project of understanding what it means to “be human”. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Gorham, Catherine Margaret
- Date: 2023-10-13
- Subjects: HIV-positive persons South Africa Makhanda , AIDS (Disease) Patients South Africa Makhanda , Social networks , Diseases Social aspects , Health services accessibility , Narrative
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432411 , vital:72868 , DOI 10.21504/10962/432411
- Description: Through the experiences of five people, this study asks how support systems develop, are used and are valued for those faced with the everyday challenges of living with HIV. Additional evidence is found in accounts from those identified as essential sources of support. These are primarily friends, sometimes family. This perspective is rounded out by insights gathered from those working in local organisations and in the analysis of services offered by the state. The three women and two men at the centre of this study live in Makhanda in the Eastern Cape, South Africa. Makhanda (formerly Grahamstown) is characterised by extremes of poverty and wealth, reflected in low employment, expanding informal and low-income settlement areas but also in a high level of community activism and access to resources. Each of the five tested positive for HIV variously between 1998 and 2008. These years were pivotal in the development of the local and national epidemic. The rapid expansion of infection rates, contestation over forms of and access to treatment, followed by emphasis of a biomedical response, in equal measure bracket and cut across their experiences. To this point, research is less concerned with what individual experiences say about living through the HIV/AIDS epidemic. Preoccupations lie more generally with macro- or micro-level factors, with behaviour change, managing risk and so public health – not the processes linking individual circumstances and choices to opportunities and outcomes described by individual, community and structural, socio-economic contexts. Personal accounts and observations of a developing, community-based, local response to an unfolding epidemic are therefore considered against the analysis of available medical and nonmedical resources. This enables identification and investigation of social processes operating between proximal and distal conditions, determining possibilities for access to support. The focus of this study thus falls to the interrelations of structure, agency and action. It contributes to an empirical and theoretical understanding of what “support” is, what “coping” means and what unfolds where diagnosis with HIV disrupts and challenges existing ways of coping and forms of support. The accounts gathered for this study offer an “insider” perspective, focused on what follows from testing positive to identifying what resources hold significance. Connections between individual, community and society, through psycho-social, local and macro-level processes are explored. Along with the empirical study of individual accounts, the thesis offers a theoretical framework that uses a grounded-theory approach in conjunction with the tools of narrative analysis. These are critically adapted from a sociology of illness studies. Ideas of risk and response, of material and social capital, of the nature of HIV/AIDS as an experience that is inclusive of both chronic, everyday challenge and critical, life-threatening crisis disrupting a sense of time, biography and self, are brought together in the analysis. In this way the understanding of what support means, how it develops and is used (systematically or not), and of the links operating between structural and social conditions, individual agency and action, can be developed. What the thesis finds is that, beyond the medical system of hospitals and clinics, there is surprisingly little use of available resources. There is thus an absence of any systematic support for those faced with the physical, psychological, social and material impacts of HIV/AIDS. Given the nature of personal circumstances, embedded as they are within local conditions that reflect structural constraints of the broader economy and society, this should not be surprising. A system of support exists in only the most limited definition. Against this, what is novel in these findings is the role that psycho-social processes play in negotiating these conditions and how this works, determining what unfolds. A key finding is that it is more through chance than choice that people do find conventional forms of support. The reasons for this have to do not only with limitations to state and institutional capacity, but also with the impact on individuals of perceptions of themselves shaped by the impact of the epidemic and also the past. The result is that under the burden of HIV/AIDS, in the context of extreme inequalities and the absence of an adequate response from the state, already invisible individuals who do not “count” run the risk of becoming doubly invisible. It is through a process of personal adaptation in which shifts in identity and a sense of self are key that they must find their own way. This involves re-conceptualisations of identity, a sense of self and place in the world. The focus on five people and the community in which they live is a limit to the scope of study Yet it is this focus which allows for a new understanding of the social processes involved, and so the links operating between individuals and society. This is of significance beyond the study of HIV/AIDS alone, contributing to the broader sociological project of understanding what it means to “be human”. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2023-10-13
Analysis of the role and regulation of HOP1a and HOP1b splice variants in cancer biology
- Authors: Schwarz, Kelly
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432240 , vital:72854
- Description: Restricted access. Expected lease date in 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Schwarz, Kelly
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432240 , vital:72854
- Description: Restricted access. Expected lease date in 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
Anonymous testimony and epistemic responsibility
- Authors: Ajiboro, Aderonke Adeyinka
- Date: 2023-10-13
- Subjects: Anonymity , Assertion , Credibility , Truthfulness and falsehood , Responsibility , Testimony (Theory of knowledge)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432286 , vital:72858 , DOI 10.21504/10962/432286
- Description: In this thesis, I examine anonymous testimony in both offline (face-to-face) and online (internet and social media) interactions and the epistemic concerns it raises in relation to belief, knowledge, justification, and normative assessments of assertions. I discuss anonymous testimony as involving a relation between the hearer and the content of the testimony in comparison to ordinary cases where the speaker of an assertion is known. In anonymous testimony, the hearer has the burden of epistemic responsibility to arrive at a testimonial belief or arguably acceptance. The hearer is also accountable for the anonymous testimony in the event of re-assertion. I also assess the norms of assertion for anonymous testimony and argue that knowledge, truth, and belief norms that apply in cases where the speaker is known should not be applied to cases of anonymous speakers. Epistemologists have paid little attention to anonymous testimony and its implications on the norms of interaction. This is a study in the epistemology of testimony and it aims at providing further understanding of the epistemic responsibility of hearers of anonymous testimony. In Chapter One, I argue that anonymous testimony can be appropriately described as testimony; where the properties of an assertion to induce belief in the hearer are sufficient to describe the assertion as testimony. I examine the kinds of anonymity and the burden of epistemic responsibility for the hearer. I introduce basically anonymous testimony in offline and online contexts of interaction. A basically anonymous testimony occurs where, at the instance of receiving testimony and making an epistemic decision on it, the speaker is unidentifiable to the hearer. In Chapter Two, I discuss the kinds of epistemic attitudes hearers may have when they receive anonymous testimony. I discuss reductionism, antireductionism, and entitlement theory as accounts of the justification for believing testimony. I argue that acceptance is the appropriate attitude and the entitlement theory provides a basis for accepting anonymous testimony. I also argue that practical reasons are a sufficient to accept anonymous testimony. Also, I discuss the possibility that a hearer of anonymous testimony can make a wrongful presumption by assigning an identity to a person as the speaker of an anonymous testimony. This can cause harm to the ‘person’ of the presumed speaker such as an unwarranted credibility assessment of the person by other people in the community. I also argue that making a credibility assessment of a presumed speaker constitutes harm to a proper epistemic assessment of the content. In Chapter Three, I discuss the possibility of trust relations between an anonymous speaker and a hearer. I argue that the hearer is solely responsible for making an epistemic decision from anonymous testimony. I argue that anonymous testimony can be relevant to a hearer given the value of its content. In Chapter Four, I discuss the applicability of knowledge, truth, belief, reasonable to believe and supportive reasons norms for the re-assertion of anonymous testimony. Hence, I argue that the supportive reasons norm, which acknowledges acceptance of an assertion, the relevance of contexts, and admits both epistemic and practical reasons to make an assertion, should guide the re-assertion of anonymous testimony. I also argue that a hearer should be epistemically conscientiousness for responsible re-assertion of received anonymous testimony. , Thesis (PhD) -- Faculty of Humanities, Philosophy, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Ajiboro, Aderonke Adeyinka
- Date: 2023-10-13
- Subjects: Anonymity , Assertion , Credibility , Truthfulness and falsehood , Responsibility , Testimony (Theory of knowledge)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432286 , vital:72858 , DOI 10.21504/10962/432286
- Description: In this thesis, I examine anonymous testimony in both offline (face-to-face) and online (internet and social media) interactions and the epistemic concerns it raises in relation to belief, knowledge, justification, and normative assessments of assertions. I discuss anonymous testimony as involving a relation between the hearer and the content of the testimony in comparison to ordinary cases where the speaker of an assertion is known. In anonymous testimony, the hearer has the burden of epistemic responsibility to arrive at a testimonial belief or arguably acceptance. The hearer is also accountable for the anonymous testimony in the event of re-assertion. I also assess the norms of assertion for anonymous testimony and argue that knowledge, truth, and belief norms that apply in cases where the speaker is known should not be applied to cases of anonymous speakers. Epistemologists have paid little attention to anonymous testimony and its implications on the norms of interaction. This is a study in the epistemology of testimony and it aims at providing further understanding of the epistemic responsibility of hearers of anonymous testimony. In Chapter One, I argue that anonymous testimony can be appropriately described as testimony; where the properties of an assertion to induce belief in the hearer are sufficient to describe the assertion as testimony. I examine the kinds of anonymity and the burden of epistemic responsibility for the hearer. I introduce basically anonymous testimony in offline and online contexts of interaction. A basically anonymous testimony occurs where, at the instance of receiving testimony and making an epistemic decision on it, the speaker is unidentifiable to the hearer. In Chapter Two, I discuss the kinds of epistemic attitudes hearers may have when they receive anonymous testimony. I discuss reductionism, antireductionism, and entitlement theory as accounts of the justification for believing testimony. I argue that acceptance is the appropriate attitude and the entitlement theory provides a basis for accepting anonymous testimony. I also argue that practical reasons are a sufficient to accept anonymous testimony. Also, I discuss the possibility that a hearer of anonymous testimony can make a wrongful presumption by assigning an identity to a person as the speaker of an anonymous testimony. This can cause harm to the ‘person’ of the presumed speaker such as an unwarranted credibility assessment of the person by other people in the community. I also argue that making a credibility assessment of a presumed speaker constitutes harm to a proper epistemic assessment of the content. In Chapter Three, I discuss the possibility of trust relations between an anonymous speaker and a hearer. I argue that the hearer is solely responsible for making an epistemic decision from anonymous testimony. I argue that anonymous testimony can be relevant to a hearer given the value of its content. In Chapter Four, I discuss the applicability of knowledge, truth, belief, reasonable to believe and supportive reasons norms for the re-assertion of anonymous testimony. Hence, I argue that the supportive reasons norm, which acknowledges acceptance of an assertion, the relevance of contexts, and admits both epistemic and practical reasons to make an assertion, should guide the re-assertion of anonymous testimony. I also argue that a hearer should be epistemically conscientiousness for responsible re-assertion of received anonymous testimony. , Thesis (PhD) -- Faculty of Humanities, Philosophy, 2023
- Full Text:
- Date Issued: 2023-10-13
Arbuscular mycorrhizal fungi associated with maize in South Africa, under conventional and conservation agricultural cultivation
- Maússe Sitoe, Sílvia Natal David
- Authors: Maússe Sitoe, Sílvia Natal David
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431846 , vital:72808
- Description: Access restricted. Expected release date in 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Maússe Sitoe, Sílvia Natal David
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431846 , vital:72808
- Description: Access restricted. Expected release date in 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
Arbuscular mycorrhizal fungi associated with wheat under conventional and conservation agricultural cultivation
- Authors: Dube, Makasithembe
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431688 , vital:72796
- Description: Access restricted. Expected release date in 2024. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Dube, Makasithembe
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431688 , vital:72796
- Description: Access restricted. Expected release date in 2024. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-10-13
Asymmetrical zinc(II) phthalocyanines conjugated to nanomaterials for degradation of organic pollutants and inactivation of Staphylococcus aureus bacteria
- Authors: Mgidlana, Sithi
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431859 , vital:72809 , DOI 10.21504/10962/431860
- Description: This thesis reports on the syntheses and characterization of asymmetrical phthalocyanines (Pcs) with different ring substituents (tert-butyl, ester, diimide, trimethoxy, acetophenone, heptanoylphenoxy, perfluorophenoxy, dimethoxy, propanoic acid, acetic acid, carboxylic acid, aminophenoxy, acrylic acid). Several nanoparticles including metal tungstate, capped with glutathione and 1-mercaptohexanol are prepared and characterized using analytical techniques. The synthesized Pcs are covalently linked to various nanoparticles (NPs) through ester and amide bonds to form Pc-NP conjugates, in order to improve their catalytic properties. The Pcs and their conjugates are characterized using different analytical techniques. The photophysics and photochemistry of the MPcs and conjugates are studied. The conjugates T). The complexes and the conjugates with nanomaterials are evaluated for singlet oxygen-generating ability. Conjugates generate higher singlet oxygen in comparison to Pc complexes alone. The photocatalytic activity of the conjugates of ZnPc complexes with NiWO4, Ag2WO4, Bi2WO6, CoWO4, and Ag-Fe3O4-based nanoparticles is evaluated based on photodegradation of methylene blue, tetracycline, and dibenzothiophene. The photocatalytic efficiencies of the synthesized phthalocyanine complexes increased in the presence of nanoparticles. This work also reports on the photodynamic antimicrobial chemotherapy activity of these materials against Staphylococcus aureus (S. aureus) bacteria in DMSO. The results indicated that silver-based nanoconjugates exhibit high antimicrobial activity with high log reductions compared to NiWO4, CoWO4, and Ag-Fe3O4-based materials. The z-scan technique is employed to experimentally test the nonlinear optical response of complexes and nanoconjugates in solution. The nonlinear absorption coefficient, third-order optical susceptibility and optical limiting threshold of the materials are obtained from the Z-scan aperture data. The nonlinear absorption parameters improved in the presence of semiconductor quantum dots, with 1-ethanoic-CdTe/ZnSeS/ZnO giving the best results due to the presence of electron-donating substituents. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Mgidlana, Sithi
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431859 , vital:72809 , DOI 10.21504/10962/431860
- Description: This thesis reports on the syntheses and characterization of asymmetrical phthalocyanines (Pcs) with different ring substituents (tert-butyl, ester, diimide, trimethoxy, acetophenone, heptanoylphenoxy, perfluorophenoxy, dimethoxy, propanoic acid, acetic acid, carboxylic acid, aminophenoxy, acrylic acid). Several nanoparticles including metal tungstate, capped with glutathione and 1-mercaptohexanol are prepared and characterized using analytical techniques. The synthesized Pcs are covalently linked to various nanoparticles (NPs) through ester and amide bonds to form Pc-NP conjugates, in order to improve their catalytic properties. The Pcs and their conjugates are characterized using different analytical techniques. The photophysics and photochemistry of the MPcs and conjugates are studied. The conjugates T). The complexes and the conjugates with nanomaterials are evaluated for singlet oxygen-generating ability. Conjugates generate higher singlet oxygen in comparison to Pc complexes alone. The photocatalytic activity of the conjugates of ZnPc complexes with NiWO4, Ag2WO4, Bi2WO6, CoWO4, and Ag-Fe3O4-based nanoparticles is evaluated based on photodegradation of methylene blue, tetracycline, and dibenzothiophene. The photocatalytic efficiencies of the synthesized phthalocyanine complexes increased in the presence of nanoparticles. This work also reports on the photodynamic antimicrobial chemotherapy activity of these materials against Staphylococcus aureus (S. aureus) bacteria in DMSO. The results indicated that silver-based nanoconjugates exhibit high antimicrobial activity with high log reductions compared to NiWO4, CoWO4, and Ag-Fe3O4-based materials. The z-scan technique is employed to experimentally test the nonlinear optical response of complexes and nanoconjugates in solution. The nonlinear absorption coefficient, third-order optical susceptibility and optical limiting threshold of the materials are obtained from the Z-scan aperture data. The nonlinear absorption parameters improved in the presence of semiconductor quantum dots, with 1-ethanoic-CdTe/ZnSeS/ZnO giving the best results due to the presence of electron-donating substituents. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-10-13
Beyond mastery: jazz, gender and power in postapartheid South Africa
- Authors: Williams, Ulagh
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432505 , vital:72876 , DOI 10.21504/10962/432512
- Description: This dissertation studies the musical lives of seven South African women who have built highprofile national and international careers as jazz musicians. Empirically it records self-reported experiences and actions that they have identified as relevant to their success within a notoriously patriarchal field. Drawing on feminist research methods and Interpretative Phenomenological Analysis the dissertation strives to develop an empathic yet critical epistemological framework attuned to the complexities of their lived experiences as women and as jazz musicians. Theoretically it investigates the power relations at play in the myriad ways they negotiate or have been impelled to negotiate gender and patriarchy as musicians. Chapter one draws attention to the ubiquity of patriarchy in South African and international jazz culture, and highlights the research participants’ numerous successes to date as performers, educators, composers, and bandleaders. Chapter two positions this study in relation to cognate work in South African jazz studies, international feminist jazz studies and feminist phenomenology. Chapters three to five successively consider the participants’ early enculturation as musical and gendered subjects, their agentic responses to structures of patriarchy and/or race as emerging and established professionals, and the ways these experiences have found expression in some of their musical utterances as performers and composers. Fusing art and activism, the participants challenge and transcend masculinist discourses of mastery that still dominate South African jazz as a field of production and aesthetic practice. , Thesis (PhD) -- Faculty of Humanities, Music and Musicology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Williams, Ulagh
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432505 , vital:72876 , DOI 10.21504/10962/432512
- Description: This dissertation studies the musical lives of seven South African women who have built highprofile national and international careers as jazz musicians. Empirically it records self-reported experiences and actions that they have identified as relevant to their success within a notoriously patriarchal field. Drawing on feminist research methods and Interpretative Phenomenological Analysis the dissertation strives to develop an empathic yet critical epistemological framework attuned to the complexities of their lived experiences as women and as jazz musicians. Theoretically it investigates the power relations at play in the myriad ways they negotiate or have been impelled to negotiate gender and patriarchy as musicians. Chapter one draws attention to the ubiquity of patriarchy in South African and international jazz culture, and highlights the research participants’ numerous successes to date as performers, educators, composers, and bandleaders. Chapter two positions this study in relation to cognate work in South African jazz studies, international feminist jazz studies and feminist phenomenology. Chapters three to five successively consider the participants’ early enculturation as musical and gendered subjects, their agentic responses to structures of patriarchy and/or race as emerging and established professionals, and the ways these experiences have found expression in some of their musical utterances as performers and composers. Fusing art and activism, the participants challenge and transcend masculinist discourses of mastery that still dominate South African jazz as a field of production and aesthetic practice. , Thesis (PhD) -- Faculty of Humanities, Music and Musicology, 2023
- Full Text:
- Date Issued: 2023-10-13
Click consonants in contact: a comparative sociohistorical analysis with special reference to Nama-Afrikaans contact
- Authors: Christie, Camilla Rose
- Date: 2023-10-13
- Subjects: Click consonant , Language contact , Sociohistorical linguistics , Sociolinguistics , Nama language , Khoekhoe , African languages , Linguistic borrowing
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432370 , vital:72865 , DOI 10.21504/10962/432370
- Description: Despite their ubiquity across southern Africa, click consonants are among the world’s most poorly understood speech sounds. Details of their phonological behaviour during language contact remain unclear, in large part because of the under-documentation of contact events of marginalised languages in rural contexts. Working within a sociohistorical linguistic framework with reference to material socioeconomic theories of language contact, this thesis compares and contrasts the diachronic phonological outcomes of various click loan events. The primary event under investigation is the donation of loanwords from an endangered click language, Nama, via substrate interference with the lexicon of a socially dominant clickless language, Afrikaans, in the Namaqualand region of the Northern Cape. The phonological adaptations employed to integrate donated lexical material into a host grammar ought ordinarily to be fairly regular, but the cross-linguistic rarity of click consonants complicates this process. The twenty click consonants expected of Nama undergo phonemic neutralisation when realised in Namaqualand Afrikaans, such that contrast embedded in click ‘type’ and click ‘accompaniment’ is collapsed. Speakers of Namaqualand Afrikaans employ any click type when uttering any click word, and may even use different click types in different tokens of the same lexical item. This unpredictability neutralises contrast. Nonetheless, there is some evidence of a diachronic trend from the unpredictable use of multiple click types and accompaniments toward the stable use of only the linguopulmonic dental click. When these novel data are set against the phonological outcomes of other contact events between a click language and a clickless languages across southern Africa, the normal outcome of click loan under is shown to be the collapse of ‘type’ contrasts. An important outlier is the large ‘type’-contrasting click inventory still shared by isiXhosa and isiZulu long after the extinction of donor click languages in the Khoekhoe branch, suggesting that this contact event must historically have entailed sustained community-wide bilingualism. These comparative observations are used to develop a cross-linguistic typology of click loan events that aims to improve our understanding of the precolonial linguistic landscape of southern Africa. The improved documentation of click consonants in rural language varieties is urgently recommended. , Thesis (PhD) -- Faculty of Humanities, Linguistics and Applied Language Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Christie, Camilla Rose
- Date: 2023-10-13
- Subjects: Click consonant , Language contact , Sociohistorical linguistics , Sociolinguistics , Nama language , Khoekhoe , African languages , Linguistic borrowing
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432370 , vital:72865 , DOI 10.21504/10962/432370
- Description: Despite their ubiquity across southern Africa, click consonants are among the world’s most poorly understood speech sounds. Details of their phonological behaviour during language contact remain unclear, in large part because of the under-documentation of contact events of marginalised languages in rural contexts. Working within a sociohistorical linguistic framework with reference to material socioeconomic theories of language contact, this thesis compares and contrasts the diachronic phonological outcomes of various click loan events. The primary event under investigation is the donation of loanwords from an endangered click language, Nama, via substrate interference with the lexicon of a socially dominant clickless language, Afrikaans, in the Namaqualand region of the Northern Cape. The phonological adaptations employed to integrate donated lexical material into a host grammar ought ordinarily to be fairly regular, but the cross-linguistic rarity of click consonants complicates this process. The twenty click consonants expected of Nama undergo phonemic neutralisation when realised in Namaqualand Afrikaans, such that contrast embedded in click ‘type’ and click ‘accompaniment’ is collapsed. Speakers of Namaqualand Afrikaans employ any click type when uttering any click word, and may even use different click types in different tokens of the same lexical item. This unpredictability neutralises contrast. Nonetheless, there is some evidence of a diachronic trend from the unpredictable use of multiple click types and accompaniments toward the stable use of only the linguopulmonic dental click. When these novel data are set against the phonological outcomes of other contact events between a click language and a clickless languages across southern Africa, the normal outcome of click loan under is shown to be the collapse of ‘type’ contrasts. An important outlier is the large ‘type’-contrasting click inventory still shared by isiXhosa and isiZulu long after the extinction of donor click languages in the Khoekhoe branch, suggesting that this contact event must historically have entailed sustained community-wide bilingualism. These comparative observations are used to develop a cross-linguistic typology of click loan events that aims to improve our understanding of the precolonial linguistic landscape of southern Africa. The improved documentation of click consonants in rural language varieties is urgently recommended. , Thesis (PhD) -- Faculty of Humanities, Linguistics and Applied Language Studies, 2023
- Full Text:
- Date Issued: 2023-10-13
Computational studies in human African trypanosomiasis
- Authors: Muronzi, Tendai
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431883 , vital:72812 , DOI 10.21504/10962/431885
- Description: Human African trypanosomiasis (HAT) is a neglected tropical disease (NTD) caused by two subspecies of the parasite, namely Trypanosoma brucei (Tb) gambiense (g-HAT) and rhodesiense (r-HAT). HAT is endemic in sub-Saharan countries, where the parasite transmission vectors, tsetse flies, breed. An estimated 70 million people remain at risk of contracting the disease, where the infection is classified as acute or chronic for g-HAT and r-HAT, respectively, with both forms ending in fatal meningoencephalitis when left untreated. Both g-HAT and r-HAT are responsible for widespread fatal epidemics throughout sub-Saharan African history, resulting from the complex molecular interplay between trypanosomes and humans through unique, innate immunity evasion mechanisms. Of interest, the Tbr subspecies expresses a serum resistance-associated protein (SRA), which binds to human serum lytic factor, apolipoprotein L1 (ApoL1), nullifying any trypanocidal activity. In response, ApoL1 (G1 and G2) variants found in humans of sub-Saharan African lineage have been cited for conferring resistance to the r-HAT infection in an interaction that is not fully elucidated In the event of successful infection, current HAT chemotherapeutics are plagued with complexity of administration, poor efficacy, toxicity, and potential drug resistance, highlighting a need for improved approaches. The parasite folate pathway provides a strategic target for alternative anti-trypanosomal drug development as trypanosomatids are folate auxotrophs, requiring host folate for growth and survival. Validated drug targets pteridine reductase (TbPTR1) and dihydrofolate reductase (TbDHFR) are essential for salvaging cofactors folate and folate biopterin crucial to parasite survival, making them viable targets for anti-folate investigation. The overall aims of this thesis were to a) provide insights into the molecular and dynamic basis of the SRA and ApoL1 interplay in HAT infection and b) identify safer and more efficient anti-folate anti-trypanosomal drug alternatives through in silico approaches. To achieve our first aim, in silico structure prediction was applied to generate 3D models of ApoL1 C-terminal variants G0, G1, G1G/M, G2 and G1G2, and four SRA variants retrieved from the NCBI database. The SRA and ApoL1 structures were inspected dynamically to identify the effect of the variants through molecular dynamics (MD) simulations. Dynamic residue network (DRN) analysis of MD trajectories was fundamental in identifying residues playing a vital role in the intramolecular communication of both proteins in the presence of mutations. Protein-protein docking was then applied to calculate plausible SRA-ApoL1 C-terminal wild-type complex structures to further elucidate the nature of SRA-mediated infection. Through MD simulations, twelve SRA-ApoL1 dimeric structures were narrowed down from five to two energetically sound complexes. The two feasible SRA-ApoL1 complexes (1 and 2) exhibited favourable communication observed through DRN analysis, including the retaining key communication residues identified in prior monomer DRN calculations. ApoL1 C-terminal variants were additionally incorporated into SRA-ApoL1 complexes 1 and 2 for further complex dynamics analysis This investigation into the nature of SRA-ApoL1 binding resulted in five primary outcomes: 1) highlighting the intramolecular effects ApoL1 variants have on the stability of the protein, 2) the identification of crucial SRA and ApoL1 communication residues in both monomeric or dimeric form, 3) the isolation of feasible SRA-ApoL1 complexes determined through global and local structural analyses 4) identification of residues crucial to the complex formation and maintenance of SRA-ApoL1, overlapping with those identified in (1), and 5) the minimal dissociative role of the G1 mutations in the complex, but compounding effect of the G2 deletion mutation. Computational modelling and drug repurposing were employed to achieve the thesis's second aim as they drastically cut down the costs involved in drug discovery and provide a more time-efficient screening method through numerous drug candidates. Using high throughput virtual screening, a subset of 2089 approved DrugBank compounds were screened against TbPTR1. The outputs were filtered to 24 viable compounds in 54 binding poses using binding energy and molecular interactions. Through subsequent MD simulations of 200ns, thirteen potential hit compounds were identified. The resultant hit compounds were subjected to further blind docking against TbDHFR and molecular dynamics to identify compounds with the potential for dual inhibition. The filtered subset was also tested in in vitro single concentration and dose-response bioassays to assess inhibitory properties against Trypanosoma brucei, complementing in silico findings. Post-molecular dynamics, four compounds exhibited high stabilities and molecular interactions with both TbPTR1 and TbDHFR, with two presenting favourable results in the in vitro assays. Three compounds additionally shared common structural moieties. In all, the in silico repurposing highlighted drugs characterised by favourable interactions and stabilities in TbPTR1, thus providing (1) a framework for further studies investigating anti-folate HAT compounds and (2) modulatory scaffolds based on identified moieties that can be used for the design of safe anti-folate trypanosomal drugs. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Muronzi, Tendai
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431883 , vital:72812 , DOI 10.21504/10962/431885
- Description: Human African trypanosomiasis (HAT) is a neglected tropical disease (NTD) caused by two subspecies of the parasite, namely Trypanosoma brucei (Tb) gambiense (g-HAT) and rhodesiense (r-HAT). HAT is endemic in sub-Saharan countries, where the parasite transmission vectors, tsetse flies, breed. An estimated 70 million people remain at risk of contracting the disease, where the infection is classified as acute or chronic for g-HAT and r-HAT, respectively, with both forms ending in fatal meningoencephalitis when left untreated. Both g-HAT and r-HAT are responsible for widespread fatal epidemics throughout sub-Saharan African history, resulting from the complex molecular interplay between trypanosomes and humans through unique, innate immunity evasion mechanisms. Of interest, the Tbr subspecies expresses a serum resistance-associated protein (SRA), which binds to human serum lytic factor, apolipoprotein L1 (ApoL1), nullifying any trypanocidal activity. In response, ApoL1 (G1 and G2) variants found in humans of sub-Saharan African lineage have been cited for conferring resistance to the r-HAT infection in an interaction that is not fully elucidated In the event of successful infection, current HAT chemotherapeutics are plagued with complexity of administration, poor efficacy, toxicity, and potential drug resistance, highlighting a need for improved approaches. The parasite folate pathway provides a strategic target for alternative anti-trypanosomal drug development as trypanosomatids are folate auxotrophs, requiring host folate for growth and survival. Validated drug targets pteridine reductase (TbPTR1) and dihydrofolate reductase (TbDHFR) are essential for salvaging cofactors folate and folate biopterin crucial to parasite survival, making them viable targets for anti-folate investigation. The overall aims of this thesis were to a) provide insights into the molecular and dynamic basis of the SRA and ApoL1 interplay in HAT infection and b) identify safer and more efficient anti-folate anti-trypanosomal drug alternatives through in silico approaches. To achieve our first aim, in silico structure prediction was applied to generate 3D models of ApoL1 C-terminal variants G0, G1, G1G/M, G2 and G1G2, and four SRA variants retrieved from the NCBI database. The SRA and ApoL1 structures were inspected dynamically to identify the effect of the variants through molecular dynamics (MD) simulations. Dynamic residue network (DRN) analysis of MD trajectories was fundamental in identifying residues playing a vital role in the intramolecular communication of both proteins in the presence of mutations. Protein-protein docking was then applied to calculate plausible SRA-ApoL1 C-terminal wild-type complex structures to further elucidate the nature of SRA-mediated infection. Through MD simulations, twelve SRA-ApoL1 dimeric structures were narrowed down from five to two energetically sound complexes. The two feasible SRA-ApoL1 complexes (1 and 2) exhibited favourable communication observed through DRN analysis, including the retaining key communication residues identified in prior monomer DRN calculations. ApoL1 C-terminal variants were additionally incorporated into SRA-ApoL1 complexes 1 and 2 for further complex dynamics analysis This investigation into the nature of SRA-ApoL1 binding resulted in five primary outcomes: 1) highlighting the intramolecular effects ApoL1 variants have on the stability of the protein, 2) the identification of crucial SRA and ApoL1 communication residues in both monomeric or dimeric form, 3) the isolation of feasible SRA-ApoL1 complexes determined through global and local structural analyses 4) identification of residues crucial to the complex formation and maintenance of SRA-ApoL1, overlapping with those identified in (1), and 5) the minimal dissociative role of the G1 mutations in the complex, but compounding effect of the G2 deletion mutation. Computational modelling and drug repurposing were employed to achieve the thesis's second aim as they drastically cut down the costs involved in drug discovery and provide a more time-efficient screening method through numerous drug candidates. Using high throughput virtual screening, a subset of 2089 approved DrugBank compounds were screened against TbPTR1. The outputs were filtered to 24 viable compounds in 54 binding poses using binding energy and molecular interactions. Through subsequent MD simulations of 200ns, thirteen potential hit compounds were identified. The resultant hit compounds were subjected to further blind docking against TbDHFR and molecular dynamics to identify compounds with the potential for dual inhibition. The filtered subset was also tested in in vitro single concentration and dose-response bioassays to assess inhibitory properties against Trypanosoma brucei, complementing in silico findings. Post-molecular dynamics, four compounds exhibited high stabilities and molecular interactions with both TbPTR1 and TbDHFR, with two presenting favourable results in the in vitro assays. Three compounds additionally shared common structural moieties. In all, the in silico repurposing highlighted drugs characterised by favourable interactions and stabilities in TbPTR1, thus providing (1) a framework for further studies investigating anti-folate HAT compounds and (2) modulatory scaffolds based on identified moieties that can be used for the design of safe anti-folate trypanosomal drugs. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
Design of an LMS-mediated tutorial to support deep and effective engagement in the process of learning mathematics
- Authors: Kigundu, Stephen
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431565 , vital:72786 , DOI 10.21504/10962/431565
- Description: Many institutions of Higher Learning have adopted a variety of Learning Management Systems (LMS) as platforms for e-learning implementation. However, the design and nature of LMS technologies present challenges to the design of LMS-based activities that engage students in learning to do mathematics. There are no clear guidelines or strategies for designing LMS-based activities that engage students in complex mathematical processes. Hence, using technologies in mathematics education often replicates instructivist positions and practices. Conversely, using constructivist principles, modes of mathematical engagement, and e-learning tools to mediate learning provides an integrated framework to transform the use of an LMS as a platform for e-learning implementation and promote deep engagement in mathematical learning. The objective of this study was to explore mechanisms that could be useful for conceiving activities to support the learning of Mathematics using an LMS-mediated tutorial. The design, redesign and evaluation of the e-tutorial are reported upon. In preparation for the study, an LMS-based tutorial was designed and developed to be used as a test-bed to investigate how these e-learning tools could support learning to do mathematics. A Trigonometry module, consisting of course content in the form of resources and tasks to help the students to explore, practice and apply right triangle concepts, was used to investigate and derive design strategies. A mixed method research approach with a reflexive self-study research design was used. A group of first-year university student volunteers studying mathematics in the mechanical engineering department were used to test the tutorial. The students were asked to do a series of tasks using the e-learning environment during the Mathematics tutorial period. Data was collected using in-class observations, interviews, screen capture videos, student-written responses, and system-generated data. All students were encouraged to complete a learning journal detailing their experiences during the tutorial using an LMS-based tool. The students were given no training, but a tutor (researcher) was available to answer any questions they may have had. Contradiction analysis was used to evaluate the data, compare purpose and practice and judge whether the activity or tool was fitted for the intended purpose. Findings were in the form of transformations of the e-tutorial system as it was developed. Among the most noteworthy contributory modifications were changing from 1) “read first, then do” to “do first, read when necessary”, 2) “work on the computer” to “work on paper then capture on the computer”, 3) “physically separated work with computer-enabled social contact”, to "individual computer work in face-to-face social settings.” 4) “single-level of resource provision” to “multi-level, demand-driven resource provision” and 5) “self-regulated” learning process regulation to “computer-assisted” learning process regulation. The discussion of these findings indicated that to enable students’ deep and effective engagement in the process of learning fundamental trigonometry within an LMS-mediated tutorial, one needs to design the system with some activities that can create a demand for knowledge, encourage rough work and face-to-face social interaction, supported by multi-level, demand-driven resources, and computer-assisted learning-process regulation. Contributions to research by this study were in the form of 1) Design Principles for LMS-mediated tutorials, 2) Principles for an e-tutorial development methodology, and 3) The LMS-mediated tutorial system. , Thesis (PhD) -- Faculty of Education, Primary and Early Childhood Education, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Kigundu, Stephen
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431565 , vital:72786 , DOI 10.21504/10962/431565
- Description: Many institutions of Higher Learning have adopted a variety of Learning Management Systems (LMS) as platforms for e-learning implementation. However, the design and nature of LMS technologies present challenges to the design of LMS-based activities that engage students in learning to do mathematics. There are no clear guidelines or strategies for designing LMS-based activities that engage students in complex mathematical processes. Hence, using technologies in mathematics education often replicates instructivist positions and practices. Conversely, using constructivist principles, modes of mathematical engagement, and e-learning tools to mediate learning provides an integrated framework to transform the use of an LMS as a platform for e-learning implementation and promote deep engagement in mathematical learning. The objective of this study was to explore mechanisms that could be useful for conceiving activities to support the learning of Mathematics using an LMS-mediated tutorial. The design, redesign and evaluation of the e-tutorial are reported upon. In preparation for the study, an LMS-based tutorial was designed and developed to be used as a test-bed to investigate how these e-learning tools could support learning to do mathematics. A Trigonometry module, consisting of course content in the form of resources and tasks to help the students to explore, practice and apply right triangle concepts, was used to investigate and derive design strategies. A mixed method research approach with a reflexive self-study research design was used. A group of first-year university student volunteers studying mathematics in the mechanical engineering department were used to test the tutorial. The students were asked to do a series of tasks using the e-learning environment during the Mathematics tutorial period. Data was collected using in-class observations, interviews, screen capture videos, student-written responses, and system-generated data. All students were encouraged to complete a learning journal detailing their experiences during the tutorial using an LMS-based tool. The students were given no training, but a tutor (researcher) was available to answer any questions they may have had. Contradiction analysis was used to evaluate the data, compare purpose and practice and judge whether the activity or tool was fitted for the intended purpose. Findings were in the form of transformations of the e-tutorial system as it was developed. Among the most noteworthy contributory modifications were changing from 1) “read first, then do” to “do first, read when necessary”, 2) “work on the computer” to “work on paper then capture on the computer”, 3) “physically separated work with computer-enabled social contact”, to "individual computer work in face-to-face social settings.” 4) “single-level of resource provision” to “multi-level, demand-driven resource provision” and 5) “self-regulated” learning process regulation to “computer-assisted” learning process regulation. The discussion of these findings indicated that to enable students’ deep and effective engagement in the process of learning fundamental trigonometry within an LMS-mediated tutorial, one needs to design the system with some activities that can create a demand for knowledge, encourage rough work and face-to-face social interaction, supported by multi-level, demand-driven resources, and computer-assisted learning-process regulation. Contributions to research by this study were in the form of 1) Design Principles for LMS-mediated tutorials, 2) Principles for an e-tutorial development methodology, and 3) The LMS-mediated tutorial system. , Thesis (PhD) -- Faculty of Education, Primary and Early Childhood Education, 2023
- Full Text:
- Date Issued: 2023-10-13
Developing a socio-economic framework for assessing the effectiveness of Expanded Public Works Programmes (EPWP): The case of the Prosopis mesquite Working for Water clearing project in the Northern Cape Province, South Africa
- Authors: Ntsonge, Sinazo
- Date: 2023-10-13
- Subjects: Public works South Africa Northern Cape Evaluation , Mesquite , South Africa. Expanded Public Works Programme , Working for Water Programme , Project management Case studies , Livelihood
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/419219 , vital:71626 , DOI 10.21504/10962/419219
- Description: The EPWP functions as a bridge between unemployment and entry into the labour market by providing work readiness skills training to its beneficiaries who receive below-market rate stipends for the short- term duration of their participation. The EPWP combines service delivery issues with social development objectives by promoting intensive manual labour in its projects. As a social protection strategy, public works programmes cater to those who do not meet the criteria to receive government social grants. As one of the programmes under the EPWP dealing with the control and eradication of invasive alien plants, the Working for Water (WfW) programme also uses intensive manual labour methods for clearing alien plant species. Although the clearing successes of WfW are well documented, the programme has focused little attention to the longer-term livelihood impacts of the temporary work and skills training provided to beneficiaries. This study suggests this could be due to a lack of the appropriate indicators to measure these outcomes. Therefore, an evaluation framework for environmental public works projects is proposed, which consists of outcome indicators to track the livelihood impact of the work experience and skills training on the beneficiaries post-participation, since the aim of these EPWP interventions is to improve beneficiaries’ labour market outcomes. The Northern Cape province’s Prosopis mesquite clearing project was used as the case study to develop and test the evaluation framework. The outcome indicators were informed by the key stakeholders’ interviews and the beneficiaries’ survey, specifically since the beneficiaries were well placed to give feedback on the benefits of the work experience and training post-participation. The combined strengths of the Sustainable Livelihoods Approach and the Capability Approach were useful for formulating the outcomes indicators, while the indicators for the inputs, activities and outputs were formulated from the key stakeholder interviews and online EPWP reports. A mixed methods approach was used and primary data were collected through key stakeholder interviews with the Prosopis mesquite clearing project managers and an online survey with some of the beneficiaries. Online EPWP reports and records obtained from WfW were used as secondary data. Data analysis used RStudio, Microsoft Excel and GraphPad Prism. The data analysis and evaluation framework indicators constituted the results section and aimed to highlight the factors that managers should focus on to achieve the desired livelihood outcomes. The proposed outcome indicators can be used to gauge the effectiveness of environmental public works’ social development interventions. The results revealed that the project budget fluctuations resulted in the Working for Water managers adopting a myopic view in administering the workdays and skills training, which diminished the livelihood impact of the Prosopis mesquite clearing project to merely a ‘make work’ project with no observable longer-term livelihood benefits. The selection input indicators and their utilisation during project activities needs to be better aligned with the desired longer-term livelihood outcomes that these environmental public works projects seek to achieve, mainly that of preparing beneficiaries for jobs in the labour market. , Thesis (PhD) -- Faculty of Commerce, Economics and Economic History, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Ntsonge, Sinazo
- Date: 2023-10-13
- Subjects: Public works South Africa Northern Cape Evaluation , Mesquite , South Africa. Expanded Public Works Programme , Working for Water Programme , Project management Case studies , Livelihood
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/419219 , vital:71626 , DOI 10.21504/10962/419219
- Description: The EPWP functions as a bridge between unemployment and entry into the labour market by providing work readiness skills training to its beneficiaries who receive below-market rate stipends for the short- term duration of their participation. The EPWP combines service delivery issues with social development objectives by promoting intensive manual labour in its projects. As a social protection strategy, public works programmes cater to those who do not meet the criteria to receive government social grants. As one of the programmes under the EPWP dealing with the control and eradication of invasive alien plants, the Working for Water (WfW) programme also uses intensive manual labour methods for clearing alien plant species. Although the clearing successes of WfW are well documented, the programme has focused little attention to the longer-term livelihood impacts of the temporary work and skills training provided to beneficiaries. This study suggests this could be due to a lack of the appropriate indicators to measure these outcomes. Therefore, an evaluation framework for environmental public works projects is proposed, which consists of outcome indicators to track the livelihood impact of the work experience and skills training on the beneficiaries post-participation, since the aim of these EPWP interventions is to improve beneficiaries’ labour market outcomes. The Northern Cape province’s Prosopis mesquite clearing project was used as the case study to develop and test the evaluation framework. The outcome indicators were informed by the key stakeholders’ interviews and the beneficiaries’ survey, specifically since the beneficiaries were well placed to give feedback on the benefits of the work experience and training post-participation. The combined strengths of the Sustainable Livelihoods Approach and the Capability Approach were useful for formulating the outcomes indicators, while the indicators for the inputs, activities and outputs were formulated from the key stakeholder interviews and online EPWP reports. A mixed methods approach was used and primary data were collected through key stakeholder interviews with the Prosopis mesquite clearing project managers and an online survey with some of the beneficiaries. Online EPWP reports and records obtained from WfW were used as secondary data. Data analysis used RStudio, Microsoft Excel and GraphPad Prism. The data analysis and evaluation framework indicators constituted the results section and aimed to highlight the factors that managers should focus on to achieve the desired livelihood outcomes. The proposed outcome indicators can be used to gauge the effectiveness of environmental public works’ social development interventions. The results revealed that the project budget fluctuations resulted in the Working for Water managers adopting a myopic view in administering the workdays and skills training, which diminished the livelihood impact of the Prosopis mesquite clearing project to merely a ‘make work’ project with no observable longer-term livelihood benefits. The selection input indicators and their utilisation during project activities needs to be better aligned with the desired longer-term livelihood outcomes that these environmental public works projects seek to achieve, mainly that of preparing beneficiaries for jobs in the labour market. , Thesis (PhD) -- Faculty of Commerce, Economics and Economic History, 2023
- Full Text:
- Date Issued: 2023-10-13
Developing and exploring a career education programme for disadvantaged FET-phase learners in the northern areas of Gqeberha: a developmental-contextual approach
- Human, Antoinette Charlotte Lucy
- Authors: Human, Antoinette Charlotte Lucy
- Date: 2023-10-13
- Subjects: Vocational education South Africa Gqeberha , Disadvantaged students , Life skills Study and teaching (Secondary) South Africa , Curriculum change South Africa , Context effects (Psychology)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432333 , vital:72862 , DOI 10.21504/10962/432333
- Description: Career development theory and assessments in South Africa have often been unscientifically applied to traditionally disadvantaged individuals, with little consideration of the diverse contexts of indigenous groups in the country. Assessment measures were not suited to the needs of learners from resource-constrained environments, nor could learners from these communities access these due to the associated financial costs. Recent research developments (using more holistic approaches) suggest that career counselling in South Africa should move towards better contextualized approaches to understanding and informing career development. Follow-up research projects show the value of such approaches with youth. Postmodern career development theories and models recognise that career counselling and development should focus on supporting individuals in constructing their careers from their own experiences within their environments, particularly for learners from disadvantaged communities whose career decisions and career development are inextricably influenced by their environments. The present study therefore employed the Developmental-Contextual Framework (DCF) to explore the perspectives of FET-phase Life Orientation (LO) educators on the LO curriculum (LO CAPS) for careers and career choices; as well as contextual factors influencing the career development of disadvantaged learners in public schools. The overall aim of the study was to co-construct and explore a customised career education programme, alongside LO educators, and determine whether FET-phase learners from disadvantaged public schools could benefit from such a programme. The DCF emphasises the dynamic relationship between an individual and the environment and the influences thereof on career development. The study draws from previous South African studies with disadvantaged learners and students that acknowledged the applicability of the DCF in the design of career programmes. This framework acknowledges the embeddedness of the individual in their proximal and distal environments and the role of these environments in the career decisionmaking of learners. The study was conducted in disadvantaged secondary schools in the Northern Areas of Gqeberha in the Eastern Cape, with LO educators in the FET-phase and the LO subject advisor at District level. At the initial interview stage the sample consisted of 9 participants and reduced to 6 participants in the focus group stage. The study underlined the impact of various contextual factors on career decision-making and the inclusion of these in career education programmes, particularly when working with learners from disadvantaged environments. Furthermore, the study illustrated that the career education of FET-phase learners in public high schools is lacking in many ways and that LO educators are not adequately trained to teach careers topics and therefore lack skills to support learners with their career development needs. The lack of, as well as poor and outdated career resources, impact negatively on the career education of learners in many public schools. Underpinned by Action Research, over a series of seven focus group meetings, an applicable and relevant programme of career-related activities based on the DCF was planned and evaluated by educators. The cumulative data were thematically analysed and the study revealed that the customised programme could potentially address the career development needs of learners from disadvantaged public schools, if educators are adequately trained to apply it. Recommendations are made for further piloting and implementation. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Human, Antoinette Charlotte Lucy
- Date: 2023-10-13
- Subjects: Vocational education South Africa Gqeberha , Disadvantaged students , Life skills Study and teaching (Secondary) South Africa , Curriculum change South Africa , Context effects (Psychology)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432333 , vital:72862 , DOI 10.21504/10962/432333
- Description: Career development theory and assessments in South Africa have often been unscientifically applied to traditionally disadvantaged individuals, with little consideration of the diverse contexts of indigenous groups in the country. Assessment measures were not suited to the needs of learners from resource-constrained environments, nor could learners from these communities access these due to the associated financial costs. Recent research developments (using more holistic approaches) suggest that career counselling in South Africa should move towards better contextualized approaches to understanding and informing career development. Follow-up research projects show the value of such approaches with youth. Postmodern career development theories and models recognise that career counselling and development should focus on supporting individuals in constructing their careers from their own experiences within their environments, particularly for learners from disadvantaged communities whose career decisions and career development are inextricably influenced by their environments. The present study therefore employed the Developmental-Contextual Framework (DCF) to explore the perspectives of FET-phase Life Orientation (LO) educators on the LO curriculum (LO CAPS) for careers and career choices; as well as contextual factors influencing the career development of disadvantaged learners in public schools. The overall aim of the study was to co-construct and explore a customised career education programme, alongside LO educators, and determine whether FET-phase learners from disadvantaged public schools could benefit from such a programme. The DCF emphasises the dynamic relationship between an individual and the environment and the influences thereof on career development. The study draws from previous South African studies with disadvantaged learners and students that acknowledged the applicability of the DCF in the design of career programmes. This framework acknowledges the embeddedness of the individual in their proximal and distal environments and the role of these environments in the career decisionmaking of learners. The study was conducted in disadvantaged secondary schools in the Northern Areas of Gqeberha in the Eastern Cape, with LO educators in the FET-phase and the LO subject advisor at District level. At the initial interview stage the sample consisted of 9 participants and reduced to 6 participants in the focus group stage. The study underlined the impact of various contextual factors on career decision-making and the inclusion of these in career education programmes, particularly when working with learners from disadvantaged environments. Furthermore, the study illustrated that the career education of FET-phase learners in public high schools is lacking in many ways and that LO educators are not adequately trained to teach careers topics and therefore lack skills to support learners with their career development needs. The lack of, as well as poor and outdated career resources, impact negatively on the career education of learners in many public schools. Underpinned by Action Research, over a series of seven focus group meetings, an applicable and relevant programme of career-related activities based on the DCF was planned and evaluated by educators. The cumulative data were thematically analysed and the study revealed that the customised programme could potentially address the career development needs of learners from disadvantaged public schools, if educators are adequately trained to apply it. Recommendations are made for further piloting and implementation. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2023
- Full Text:
- Date Issued: 2023-10-13
Disaster risk management issues in WASH in South Africa: an examination of selected challenges and development of possible solutions
- Authors: Madikizela, Phindile
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431520 , vital:72782
- Description: Access restricted. Expected release date 2025. , Thesis (PhD) -- Faculty of Pharmacy, Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Madikizela, Phindile
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431520 , vital:72782
- Description: Access restricted. Expected release date 2025. , Thesis (PhD) -- Faculty of Pharmacy, Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-13
Discovery and classification of compact radio sources in the MeerKAT Galactic Centre data
- Authors: Rammala, Isabella Dineo
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432218 , vital:72852
- Description: Access restricted. Expected release date in 2025. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Rammala, Isabella Dineo
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432218 , vital:72852
- Description: Access restricted. Expected release date in 2025. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2023
- Full Text:
- Date Issued: 2023-10-13
Enhancing the electrocatalytic activity of phthalocyanines through finding the ideal combination of substituents in push-pull phthalocyanine-based systems
- Nkhahle, Reitumetse Precious
- Authors: Nkhahle, Reitumetse Precious
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432578 , vital:72882 , DOI 10.21504/10962/432578
- Description: Phthalocyanines (Pcs) are a class of synthetic pigments with a similar structure to porphyrins. The work presented in this thesis is centred around these electron-rich macrocycles and their use in electrocatalysis. This body of work provides a more rigorous analysis on asymmetric Pcs, focusing on finding the “ideal” combination of substituents in the synthesis of A3B-type Pcs and how these asymmetric structures compare with their symmetric counterparts (A4) in the electrocatalysis of hydrazine and nitrite. The choice in substituents in the syntheses of the Pcs was such that there is both electron-donating and electron-withdrawing groups to induce a push-pull effect. In the studies involving the electrocatalysis of hydrazine, asymmetric cobalt Pcs (CoPcs) possessing alkyl groups as the primary substituents, with variations in the acid-containing group, along with their symmetric counterparts, probes with potential for further improvement were identified. Using voltammetric and amperometric techniques, the analyte-electrode kinetics, mechanism in which the electrochemical reaction proceeds along with the limits of detection (LoD) were determined. In the general sense, the pentadecylphenoxy-derived CoPcs performed better than those containing the tert-butyl substituent as the dominant substituent with the asymmetric CoPcs producing more favourable results than their symmetric analogues. With respect to the probes designed for nitrite, a multi-dimensional approach was undertaken in that acetaminophen was chosen as the primary substituent whilst multiple changes in the asymmetric component were made. In addition to varying the carboxylic acid-containing substituent, alkyne- and amine-based substituents were also explored in which the alkyne-containing Pc was anchored onto the electrode surface through click chemistry while the amine-bearing Pc was covalently linked (and π-stacked) to nitrogen-doped graphene quantum dots (NGQDs). Another component that was altered was the central metal where CoPcs were compared to manganese Pcs (MnPcs). The most desirable peak oxidation potential for nitrite was observed in the MnPcs as it was the lowest with adsorption sometimes being a better suited method of electrode modification relative to clicking. The inclusion of NGQDs was found to be beneficial when combined with the symmetric CoPc whilst in the presence of an asymmetric Pc complex, less desirable results were observed. Overall, there were variations in the results with the symmetric CoPc sometimes being better than some of the asymmetric CoPcs demonstrating that a blanket-approach in terms of synthesizing and applying asymmetric Pcs is not always viable. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Nkhahle, Reitumetse Precious
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432578 , vital:72882 , DOI 10.21504/10962/432578
- Description: Phthalocyanines (Pcs) are a class of synthetic pigments with a similar structure to porphyrins. The work presented in this thesis is centred around these electron-rich macrocycles and their use in electrocatalysis. This body of work provides a more rigorous analysis on asymmetric Pcs, focusing on finding the “ideal” combination of substituents in the synthesis of A3B-type Pcs and how these asymmetric structures compare with their symmetric counterparts (A4) in the electrocatalysis of hydrazine and nitrite. The choice in substituents in the syntheses of the Pcs was such that there is both electron-donating and electron-withdrawing groups to induce a push-pull effect. In the studies involving the electrocatalysis of hydrazine, asymmetric cobalt Pcs (CoPcs) possessing alkyl groups as the primary substituents, with variations in the acid-containing group, along with their symmetric counterparts, probes with potential for further improvement were identified. Using voltammetric and amperometric techniques, the analyte-electrode kinetics, mechanism in which the electrochemical reaction proceeds along with the limits of detection (LoD) were determined. In the general sense, the pentadecylphenoxy-derived CoPcs performed better than those containing the tert-butyl substituent as the dominant substituent with the asymmetric CoPcs producing more favourable results than their symmetric analogues. With respect to the probes designed for nitrite, a multi-dimensional approach was undertaken in that acetaminophen was chosen as the primary substituent whilst multiple changes in the asymmetric component were made. In addition to varying the carboxylic acid-containing substituent, alkyne- and amine-based substituents were also explored in which the alkyne-containing Pc was anchored onto the electrode surface through click chemistry while the amine-bearing Pc was covalently linked (and π-stacked) to nitrogen-doped graphene quantum dots (NGQDs). Another component that was altered was the central metal where CoPcs were compared to manganese Pcs (MnPcs). The most desirable peak oxidation potential for nitrite was observed in the MnPcs as it was the lowest with adsorption sometimes being a better suited method of electrode modification relative to clicking. The inclusion of NGQDs was found to be beneficial when combined with the symmetric CoPc whilst in the presence of an asymmetric Pc complex, less desirable results were observed. Overall, there were variations in the results with the symmetric CoPc sometimes being better than some of the asymmetric CoPcs demonstrating that a blanket-approach in terms of synthesizing and applying asymmetric Pcs is not always viable. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-10-13
Exploring the drivers of co-occurring multiple non-native fish assemblages within an invaded and flow-modified African river system
- Authors: Mpopetsi, Pule Peter
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431871 , vital:72810 , DOI 10.21504/10962/431871
- Description: Globally, there is growing concern on the negative impacts of species invasions and habitat disturbance because these have been shown to have the potential to disrupt native community structure and function. In some instances, these two stressors can occur in concert, such as in river systems associated with inter-basin water transfer (IBWT) schemes. The Great Fish River in the Eastern Cape, South Africa, is an example of a system affected by both habitat modification and multiple fish invasions largely because of an IBWT scheme. The opening of the Orange-Fish IBWT, which transfers water from the Orange River to the Great Fish River, modified the latter’s natural flow regime from irregular seasonal to perennial. In addition, the IBWT facilitated translocations of five fish species from the Gariep Dam (Orange River system) into the Great Fish River system. Proliferation of these non-native fish species, along with that of other fish species introduced for angling and biological control, raise questions on the mechanisms facilitating their existence within this highly modified river system. This thesis explored mechanisms associated with co-occurrences of these multiple non-native fishes within the Great Fish River. A comparison of historical and contemporary records on the ichthyofauna of the Great Fish River revealed that, of the 11 non-native fishes reported in this system, seven have established successfully, three have failed to establish and the status of one was uncertain. The Orange-Fish IBWT and angling were the main vectors of these invasions, accounting for 36% and 46%, respectively. The study also found that most established non-native fish species were large sized, had high longevity and wide habitat tolerance. Trait-based approaches were employed to investigate the role of functional diversity of non-native and native fishes in relation to their composition, distribution and environmental relationships. Although considerable interspecific variation in body morphology-related functional traits among species were observed, there was no clear distinction in these traits between native and non-native fish assemblages on a trait-ordination space. Furthermore, there were weak species-trait-environment relationships, suggesting that environmental filtering was less plausible in explaining the occurrence patterns of these fishes. Stable isotope-based trophic relationships were evaluated in three invaded sections: the upper (UGFR) mainstem sections of the Great Fish River; and lower (LGFR) mainstem sections of the Great Fish River; and its tributary, the Koonap River. It was observed that native and non-native fish assemblages exhibited variation in isotopic diversity typified by low isotopic diversity overlaps in UGFR and Koonap River, whereas the LGFR was characterised by high isotopic diversity overlap. Within the invaded sections, non-native fishes were found to have isotopic niches characterised by variable isotopic niche sizes and were more isotopically dissimilar with propensity towards trophic differentiation within the UGFR and Koonap River but were mostly characterised by high isotope niche overlaps in the LGFR. Overall, these results provided evidence of trophic niche differentiation as a probable mechanism associated with the co-occurrences of the non-native fishes. However, mechanisms facilitating these co-occurrences within the invaded sections appears to be complex, context-specific and, in some cases, unclear. Lastly, machine learning techniques, boosted (BRT) and multivariate (MRT) regression trees, revealed that the flow-disturbed habitats were invaded by multiple non-native species, whereas the non-disturbed headwaters remained invasion free. In addition, non-native species were predicted to co-occur with native species within the mainstem and large tributary sections of the Great Fish River system. Thus, the IBWT-disturbed mainstem sections were predicted to be more prone to multiple invasions compared to undisturbed headwater tributaries. , Tlhaselo ka mefuta ya diphoofolo-tsa-matswantle (non-native species), ha mmoho le phetolo/tsenyehelo ya bodulo ba diphoofolo-tsa-lehae (native species), di nkuwa ele tse pedi tsa tse kgolo ka ho fetisisa hara ditshoso tse kgahlanong le paballo kapa tshireletso ya diphoofolo-tsa-lehae tse phelang dinokeng kapa metsing. Maemong a mang, dikgatello tsena tse pedi dika etsahala ka nako e le nngwe, jwalo ka dinokeng tseo di amanang le maano a ho fetisa/tsamaisa metsi pakeng tsa dinoka tse fapa-fapaneng (IBWT). Enngwe ya dinoka tse jwalo, ke noka e bitswang ka Great Fish River, e fumanehang Kapa-Botjabela (Eastern Cape) ka hara naha ya Afrika Borwa (South Africa). Noka ena ya Great Fish River e angwa ke tshenyehelo ya bodulo ba ditlhapi-tsa-lehae, ha mmoho le tlhaselo ya tsona ka ditlhapi-tsa-matswantle. Tsena di etsahala hahololo ka lebaka la morero kapa leano la phepelo ya metsi le bitswang Orange-Fish IBWT, leo lona le ileng la fetola phallo ya tlhaho ya metsi a Great Fish River. Ho feta moo, leano lena la phephelo yametsi, Orange-Fish IBWT, le entse hore ho be bonolo ho fetisetswa ha mefuta e mehlano ya ditlhapi-tsa-matswantle ho tloha letamong le bitswang Gariep Dam, hoya kena ka hara noka ya Great Fish River. Ditla morao tsa tsena tsohle, ebile ho ata ha mefuta e mengata ya ditlhapi-tsa-matswantle ka hara noka ya Great Fish River. Ho ata hona ha ditlapi-tsa-matswantle ka hara noka ena ya Great Fish River, ho hlahisa dipotso mabapi le mekgwa e bebofatsang ho phela ha ditlhapi tsena tsa matswantle ka hara noka ena; hore ana ebe diphela jwang ka hara noka ya Great Fish River? Ka hona, sepheo le merero wa thuto ena ke ho phuputsa mekgwa e bebofatsang ho phela ha mefuta ena e fapaneng ya ditlhapi-tsa-matswantle ka hara noka ya Great Fish River. Dipheto tsa diphuputso di hlalosa hore, ha jwale, ka hara noka ena ya Great Fish River, hona le ditlhapi-tsa-matswantle tse leshome le motso o mong (11). Bosupa (7) ba tsona di phela ka katleho, ha tse tharo di hlolehile ho theha (3), mme e le nngwe (1) boemo ba teng ha bo hlake. Hare lekola hore ke efeng mekgwa e amanang le ho ata ha ditlhapi-tsa-matswantle ka hara Great Fish River, re fumana hore leano la phephelo ya metsi la Orange-Fish IBWT ka 36%, ha mmoho le boithapollo ba ho tshwasa ditlhapi (angling) ka 46%, ene ele tsona tsela tsa ho kena ha ditlhapi-tsa-matswantle ka hara Great Fish River, tse ka sehlohong. Re fumantsha hape hore katleho ya ditlhapi-tsa-matswantle e amahangwa le hore di boholo bo bokae, le hore diphela nako e ka kang. Mohlala, ditlhapi tse kgolo tse phelang nako etelele ka tlhaho ya tsona, di amahangwa le katleho ya ho theha ka hara noka ena. Ha tseo tse phelang nako e kgutshwanyane tsona disa amahangwe leho atleha ka hara noka ena. Tse ding tsa dipheto di hlalosa hore, ditlhapi-tsa-lehae le ditlhapi-tsa-matswantle, ka karolelano, hadi fapane haholo ka dibopeho tsa mmele, dihlopa tsena tse pedi diya tshwana. Re fumantsha hape hore dihlopa tsena tse pedi tsa ditlapi dija mefuta e fapaneng ya dijo. Eleng engwe ya dintho tse netefatsang katleho ya ditlhapi-tsa-matswantle ka hara noka ena ya Great fish river. Hona keka lebaka la hore, dihlopa tsena tse pedi hadi bakisane dijo, empa di phela ka mefuta e fapaneng ya dijo. Hare phethela, re fumantsha hore mefuta e fapafapaneng ya ditlhapi-tsa-matswantle e fumaneha feela ka hara madulo a amahangwang le phethoho ya phallo ya metsi (flow alteration), madulo asa amahangwang le phetoho ya phallo ya metsi ona ane a hloka ditlhapi-tsa-matswantle. Sena se bolela hore phetolo ya phallo ya metsi ya Great Fish River, ka lebaka la Orange-Fish IBWT, e fokoditse matla a noka ena ho lwantsha tlhaselo ya ditlhapi-tsa-matswantle. Ka hona, ho bobebe hore ditlhapi-tsa-matswantle di thehe ka katleho ka hara noka ena. Tsena tsohle keka baka la phetolo ya phallo ya metsi a Great Fish River e bakilweng ke leano la phephelo ya metsi la Orange-Fish IBWT. , Thesis (PhD) -- Faculty of Science, Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Mpopetsi, Pule Peter
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431871 , vital:72810 , DOI 10.21504/10962/431871
- Description: Globally, there is growing concern on the negative impacts of species invasions and habitat disturbance because these have been shown to have the potential to disrupt native community structure and function. In some instances, these two stressors can occur in concert, such as in river systems associated with inter-basin water transfer (IBWT) schemes. The Great Fish River in the Eastern Cape, South Africa, is an example of a system affected by both habitat modification and multiple fish invasions largely because of an IBWT scheme. The opening of the Orange-Fish IBWT, which transfers water from the Orange River to the Great Fish River, modified the latter’s natural flow regime from irregular seasonal to perennial. In addition, the IBWT facilitated translocations of five fish species from the Gariep Dam (Orange River system) into the Great Fish River system. Proliferation of these non-native fish species, along with that of other fish species introduced for angling and biological control, raise questions on the mechanisms facilitating their existence within this highly modified river system. This thesis explored mechanisms associated with co-occurrences of these multiple non-native fishes within the Great Fish River. A comparison of historical and contemporary records on the ichthyofauna of the Great Fish River revealed that, of the 11 non-native fishes reported in this system, seven have established successfully, three have failed to establish and the status of one was uncertain. The Orange-Fish IBWT and angling were the main vectors of these invasions, accounting for 36% and 46%, respectively. The study also found that most established non-native fish species were large sized, had high longevity and wide habitat tolerance. Trait-based approaches were employed to investigate the role of functional diversity of non-native and native fishes in relation to their composition, distribution and environmental relationships. Although considerable interspecific variation in body morphology-related functional traits among species were observed, there was no clear distinction in these traits between native and non-native fish assemblages on a trait-ordination space. Furthermore, there were weak species-trait-environment relationships, suggesting that environmental filtering was less plausible in explaining the occurrence patterns of these fishes. Stable isotope-based trophic relationships were evaluated in three invaded sections: the upper (UGFR) mainstem sections of the Great Fish River; and lower (LGFR) mainstem sections of the Great Fish River; and its tributary, the Koonap River. It was observed that native and non-native fish assemblages exhibited variation in isotopic diversity typified by low isotopic diversity overlaps in UGFR and Koonap River, whereas the LGFR was characterised by high isotopic diversity overlap. Within the invaded sections, non-native fishes were found to have isotopic niches characterised by variable isotopic niche sizes and were more isotopically dissimilar with propensity towards trophic differentiation within the UGFR and Koonap River but were mostly characterised by high isotope niche overlaps in the LGFR. Overall, these results provided evidence of trophic niche differentiation as a probable mechanism associated with the co-occurrences of the non-native fishes. However, mechanisms facilitating these co-occurrences within the invaded sections appears to be complex, context-specific and, in some cases, unclear. Lastly, machine learning techniques, boosted (BRT) and multivariate (MRT) regression trees, revealed that the flow-disturbed habitats were invaded by multiple non-native species, whereas the non-disturbed headwaters remained invasion free. In addition, non-native species were predicted to co-occur with native species within the mainstem and large tributary sections of the Great Fish River system. Thus, the IBWT-disturbed mainstem sections were predicted to be more prone to multiple invasions compared to undisturbed headwater tributaries. , Tlhaselo ka mefuta ya diphoofolo-tsa-matswantle (non-native species), ha mmoho le phetolo/tsenyehelo ya bodulo ba diphoofolo-tsa-lehae (native species), di nkuwa ele tse pedi tsa tse kgolo ka ho fetisisa hara ditshoso tse kgahlanong le paballo kapa tshireletso ya diphoofolo-tsa-lehae tse phelang dinokeng kapa metsing. Maemong a mang, dikgatello tsena tse pedi dika etsahala ka nako e le nngwe, jwalo ka dinokeng tseo di amanang le maano a ho fetisa/tsamaisa metsi pakeng tsa dinoka tse fapa-fapaneng (IBWT). Enngwe ya dinoka tse jwalo, ke noka e bitswang ka Great Fish River, e fumanehang Kapa-Botjabela (Eastern Cape) ka hara naha ya Afrika Borwa (South Africa). Noka ena ya Great Fish River e angwa ke tshenyehelo ya bodulo ba ditlhapi-tsa-lehae, ha mmoho le tlhaselo ya tsona ka ditlhapi-tsa-matswantle. Tsena di etsahala hahololo ka lebaka la morero kapa leano la phepelo ya metsi le bitswang Orange-Fish IBWT, leo lona le ileng la fetola phallo ya tlhaho ya metsi a Great Fish River. Ho feta moo, leano lena la phephelo yametsi, Orange-Fish IBWT, le entse hore ho be bonolo ho fetisetswa ha mefuta e mehlano ya ditlhapi-tsa-matswantle ho tloha letamong le bitswang Gariep Dam, hoya kena ka hara noka ya Great Fish River. Ditla morao tsa tsena tsohle, ebile ho ata ha mefuta e mengata ya ditlhapi-tsa-matswantle ka hara noka ya Great Fish River. Ho ata hona ha ditlapi-tsa-matswantle ka hara noka ena ya Great Fish River, ho hlahisa dipotso mabapi le mekgwa e bebofatsang ho phela ha ditlhapi tsena tsa matswantle ka hara noka ena; hore ana ebe diphela jwang ka hara noka ya Great Fish River? Ka hona, sepheo le merero wa thuto ena ke ho phuputsa mekgwa e bebofatsang ho phela ha mefuta ena e fapaneng ya ditlhapi-tsa-matswantle ka hara noka ya Great Fish River. Dipheto tsa diphuputso di hlalosa hore, ha jwale, ka hara noka ena ya Great Fish River, hona le ditlhapi-tsa-matswantle tse leshome le motso o mong (11). Bosupa (7) ba tsona di phela ka katleho, ha tse tharo di hlolehile ho theha (3), mme e le nngwe (1) boemo ba teng ha bo hlake. Hare lekola hore ke efeng mekgwa e amanang le ho ata ha ditlhapi-tsa-matswantle ka hara Great Fish River, re fumana hore leano la phephelo ya metsi la Orange-Fish IBWT ka 36%, ha mmoho le boithapollo ba ho tshwasa ditlhapi (angling) ka 46%, ene ele tsona tsela tsa ho kena ha ditlhapi-tsa-matswantle ka hara Great Fish River, tse ka sehlohong. Re fumantsha hape hore katleho ya ditlhapi-tsa-matswantle e amahangwa le hore di boholo bo bokae, le hore diphela nako e ka kang. Mohlala, ditlhapi tse kgolo tse phelang nako etelele ka tlhaho ya tsona, di amahangwa le katleho ya ho theha ka hara noka ena. Ha tseo tse phelang nako e kgutshwanyane tsona disa amahangwe leho atleha ka hara noka ena. Tse ding tsa dipheto di hlalosa hore, ditlhapi-tsa-lehae le ditlhapi-tsa-matswantle, ka karolelano, hadi fapane haholo ka dibopeho tsa mmele, dihlopa tsena tse pedi diya tshwana. Re fumantsha hape hore dihlopa tsena tse pedi tsa ditlapi dija mefuta e fapaneng ya dijo. Eleng engwe ya dintho tse netefatsang katleho ya ditlhapi-tsa-matswantle ka hara noka ena ya Great fish river. Hona keka lebaka la hore, dihlopa tsena tse pedi hadi bakisane dijo, empa di phela ka mefuta e fapaneng ya dijo. Hare phethela, re fumantsha hore mefuta e fapafapaneng ya ditlhapi-tsa-matswantle e fumaneha feela ka hara madulo a amahangwang le phethoho ya phallo ya metsi (flow alteration), madulo asa amahangwang le phetoho ya phallo ya metsi ona ane a hloka ditlhapi-tsa-matswantle. Sena se bolela hore phetolo ya phallo ya metsi ya Great Fish River, ka lebaka la Orange-Fish IBWT, e fokoditse matla a noka ena ho lwantsha tlhaselo ya ditlhapi-tsa-matswantle. Ka hona, ho bobebe hore ditlhapi-tsa-matswantle di thehe ka katleho ka hara noka ena. Tsena tsohle keka baka la phetolo ya phallo ya metsi a Great Fish River e bakilweng ke leano la phephelo ya metsi la Orange-Fish IBWT. , Thesis (PhD) -- Faculty of Science, Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
Exploring the interplay between foundation phase learners’ home and school literacy practices
- Authors: Magxala, Xoliswa Patience
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431587 , vital:72788 , DOI 10.21504/10962/431587
- Description: The thesis looked at Foundation Phase children’s early home literacy practices and examined how these literacy practices are adopted at school in Libode, Eastern Cape Province, South Africa, a rural area. The purpose of the study was to determine how early literacy practices at home are adopted in classrooms. The study aimed to determine the relationship between home and school literacy. To understand the literacy practices used at home and school by four Foundation Phase children and four Foundation Phase teachers, an interpretive ethnographic study design was used. Participants who spoke isiXhosa as their first language participated in data collection using structured observations, video and audio recordings, field notes, and unstructured interviews. The study’s framework, the Cultural Historical Activity Theory, was used as a tool to collect, examine, and interpret data through its various components. Themes were identified, arranged, and categorized. The findings revealed children from low socioeconomic backgrounds have rich literacy practices. Teachers do not acknowledge or recognize the contributions that these children’s cultural backgrounds make. The study recommends that schools start acknowledging the advantages that children’s environments have for them. It also suggests that teachers build on the knowledge that children bring from home, as this will have an impact on how they behave in class because students bring their family’s literacy habits, which serve as the foundation for their academic literacy habits, to school. , Thesis (PhD) -- Faculty of Education, Institute for the Study of Englishes in Africa, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Magxala, Xoliswa Patience
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431587 , vital:72788 , DOI 10.21504/10962/431587
- Description: The thesis looked at Foundation Phase children’s early home literacy practices and examined how these literacy practices are adopted at school in Libode, Eastern Cape Province, South Africa, a rural area. The purpose of the study was to determine how early literacy practices at home are adopted in classrooms. The study aimed to determine the relationship between home and school literacy. To understand the literacy practices used at home and school by four Foundation Phase children and four Foundation Phase teachers, an interpretive ethnographic study design was used. Participants who spoke isiXhosa as their first language participated in data collection using structured observations, video and audio recordings, field notes, and unstructured interviews. The study’s framework, the Cultural Historical Activity Theory, was used as a tool to collect, examine, and interpret data through its various components. Themes were identified, arranged, and categorized. The findings revealed children from low socioeconomic backgrounds have rich literacy practices. Teachers do not acknowledge or recognize the contributions that these children’s cultural backgrounds make. The study recommends that schools start acknowledging the advantages that children’s environments have for them. It also suggests that teachers build on the knowledge that children bring from home, as this will have an impact on how they behave in class because students bring their family’s literacy habits, which serve as the foundation for their academic literacy habits, to school. , Thesis (PhD) -- Faculty of Education, Institute for the Study of Englishes in Africa, 2023
- Full Text:
- Date Issued: 2023-10-13