Statistical classification, an application to credit default
- Authors: Sikhakhane, Anele Gcina
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/465069 , vital:76570
- Description: Statistical learning has been used in both industry and academia to create credit scoring models. These models are used to predict who might default on their loan repayments, thus minimizing the risk financial institutions face. In this study six traditional and one more recent classifier, namely kNN, LDA, CART, RF, AdaBoost, XGBoost and SynBoost were used to predict who might default on their loans. The data set used in this study was imbalanced thus sampling and performance evaluation techniques were investigated and used to balance the class distribution and assess the classifiers performance. In addition to the standard variables and data set, new variables called synthetic variables and synthetic data sets were produced, investigated and used to predict who might default on their loans. This study found that the synthetic data set had strong predictive power and sampling methods negatively affected the classifiers performance. The best-performing classifier was XGBoost, with an AUC score of 0.7732. , Thesis (MSc) -- Faculty of Science, Statistics, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Sikhakhane, Anele Gcina
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/465069 , vital:76570
- Description: Statistical learning has been used in both industry and academia to create credit scoring models. These models are used to predict who might default on their loan repayments, thus minimizing the risk financial institutions face. In this study six traditional and one more recent classifier, namely kNN, LDA, CART, RF, AdaBoost, XGBoost and SynBoost were used to predict who might default on their loans. The data set used in this study was imbalanced thus sampling and performance evaluation techniques were investigated and used to balance the class distribution and assess the classifiers performance. In addition to the standard variables and data set, new variables called synthetic variables and synthetic data sets were produced, investigated and used to predict who might default on their loans. This study found that the synthetic data set had strong predictive power and sampling methods negatively affected the classifiers performance. The best-performing classifier was XGBoost, with an AUC score of 0.7732. , Thesis (MSc) -- Faculty of Science, Statistics, 2024
- Full Text:
- Date Issued: 2024-10-11
Structural dynamic investigation of the mutation-induced resistance mechanisms of Mycobacterium tuberculosis DNA-directed RNA polymerase against Rifampicin
- Authors: Monama, Mokgerwa Zacharia
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466849 , vital:76792 , DOI https://doi.org/10.21504/10962/466849
- Description: Emerging resistant strains of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB) disease, continue to plague mankind and reduce the efficacies of antitubercular therapies that have been an effective defence against TB for decades. More specifically, mutations located in the β subunit of the multisubunit Mtb RNA replicative machinery, RNA polymerase (RNAP), have been well established as the reason behind resistance to the first-line antitubercular drug rifampicin (RIF), which has resulted in therapeutic failure in several clinical cases. Additionally, elusive details pertaining to the underlying mechanisms associated with RIF resistance due to the presence of Mtb-RNAP-β mutations, have resulted in setbacks in the development of novel and effective drugs that might be able to curb the ongoing threat. Hence, in this investigation, we attempted to resolve the involved Mtb-RNAP structural events at the molecular level to discern potentially important details regarding the nine clinically relevant Mtb-RNAP-β missense mutations under investigation. Hence, for the first time, we conducted an in-silico RIF resistance investigation using the Mtb-RNAP complex. To accomplish the set-out task, we first employed the use of more traditional post-MD analytical approaches such as root mean square deviation, root mean square fluctuation, radius of gyration, center of mass distance analyses, hydrogen bond occupancies, and binding free energy calculations, to conduct a global analysis of the mutated Mtb-RNAP proteins referencing RIF efficacy. Our findings revealed that the mutations may have a perturbation effect resulting in the disruption of essential structural dynamics attributed to the protein’s catalytic functions. This was for instance observed for the βfork loop 2 domain, the β’zinc-binding domain, the β’ trigger loop domain, and the β’jaw domain, which happen to be in line with previously reported experiments detailing changes in RNAP processivity. Complementarily, some of the mutations more specifically perturbed the RIF binding pocket (RIF-BP) which observably led to the reorientation of RIF from the native or active orientation needed to obstruct the processive addition of nucleoside triphosphates to the growing RNA transcript. The mutation-induced repositioning from the active RIF orientation was also reflected through the loss of essential interactions between RIF and the RIF-BP along with the loss of binding affinities captured for a majority of the mutant proteins. In conjunction with traditional analytical approaches, we further employed computational alanine scanning, weighted contact map analyses, and dynamic residue network (DRN) analyses, a novel approach that delineates residue-residue communication pathways through several metrics, to further elucidate how a set of clinically relevant mutations affect Mtb-RNAP function. With that, we were able to observe several key changes in residue importance and interactions that may be instrumental in bringing about RIF resistance and the compensatory conformational changes we observed among the mt systems through global analysis. Furthermore, we identified persistent hubs that may be particularly important in maintaining transcriptional activities in the presence and absence of the investigated mutations and RIF that could serve as potential resistance markers for future therapeutic investigations. We believe these findings will significantly aid future efforts in the discovery of new treatment options with the potential to overcome antitubercular resistance. , Thesis (PhD) -- Faculty of Science, Biochemistry, Microbiology and Bioinformatics, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Monama, Mokgerwa Zacharia
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466849 , vital:76792 , DOI https://doi.org/10.21504/10962/466849
- Description: Emerging resistant strains of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB) disease, continue to plague mankind and reduce the efficacies of antitubercular therapies that have been an effective defence against TB for decades. More specifically, mutations located in the β subunit of the multisubunit Mtb RNA replicative machinery, RNA polymerase (RNAP), have been well established as the reason behind resistance to the first-line antitubercular drug rifampicin (RIF), which has resulted in therapeutic failure in several clinical cases. Additionally, elusive details pertaining to the underlying mechanisms associated with RIF resistance due to the presence of Mtb-RNAP-β mutations, have resulted in setbacks in the development of novel and effective drugs that might be able to curb the ongoing threat. Hence, in this investigation, we attempted to resolve the involved Mtb-RNAP structural events at the molecular level to discern potentially important details regarding the nine clinically relevant Mtb-RNAP-β missense mutations under investigation. Hence, for the first time, we conducted an in-silico RIF resistance investigation using the Mtb-RNAP complex. To accomplish the set-out task, we first employed the use of more traditional post-MD analytical approaches such as root mean square deviation, root mean square fluctuation, radius of gyration, center of mass distance analyses, hydrogen bond occupancies, and binding free energy calculations, to conduct a global analysis of the mutated Mtb-RNAP proteins referencing RIF efficacy. Our findings revealed that the mutations may have a perturbation effect resulting in the disruption of essential structural dynamics attributed to the protein’s catalytic functions. This was for instance observed for the βfork loop 2 domain, the β’zinc-binding domain, the β’ trigger loop domain, and the β’jaw domain, which happen to be in line with previously reported experiments detailing changes in RNAP processivity. Complementarily, some of the mutations more specifically perturbed the RIF binding pocket (RIF-BP) which observably led to the reorientation of RIF from the native or active orientation needed to obstruct the processive addition of nucleoside triphosphates to the growing RNA transcript. The mutation-induced repositioning from the active RIF orientation was also reflected through the loss of essential interactions between RIF and the RIF-BP along with the loss of binding affinities captured for a majority of the mutant proteins. In conjunction with traditional analytical approaches, we further employed computational alanine scanning, weighted contact map analyses, and dynamic residue network (DRN) analyses, a novel approach that delineates residue-residue communication pathways through several metrics, to further elucidate how a set of clinically relevant mutations affect Mtb-RNAP function. With that, we were able to observe several key changes in residue importance and interactions that may be instrumental in bringing about RIF resistance and the compensatory conformational changes we observed among the mt systems through global analysis. Furthermore, we identified persistent hubs that may be particularly important in maintaining transcriptional activities in the presence and absence of the investigated mutations and RIF that could serve as potential resistance markers for future therapeutic investigations. We believe these findings will significantly aid future efforts in the discovery of new treatment options with the potential to overcome antitubercular resistance. , Thesis (PhD) -- Faculty of Science, Biochemistry, Microbiology and Bioinformatics, 2024
- Full Text:
- Date Issued: 2024-10-11
Students' perception of pre-exposure prophylaxis as a prevention strategy for reducing HIV/AIDS incidences at Rhodes University
- Authors: Lepelesana, Mamorena Sylvia
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/466150 , vital:76701
- Description: South Africa has the largest number of people living with HIV/AIDS compared to the rest of the world, with young people most at risk. The World Health Organisation (WHO) recommends the use of Pre-Exposure Prophylaxis (PrEP) in key populations at a higher risk of exposure to HIV/AIDS. The HIV/AIDS pandemic remains a pressing issue among higher education institutions, with a need for a comprehensive understanding of barriers and facilitators associated with the use of PrEP. The Higher Education AIDS (HEAIDS) plays a pivotal role in the mitigation of the spread of HIV/AIDS in Higher Education Institutions (HEIs). In this study, Rhodes University serves as a focal point for exploring PrEP implementation and acceptance. This qualitative study examines Rhodes University students' PrEP knowledge, perception, practice, and roll-out preference. More evidence is required to measure progress among students. A study was conducted involving sixteen (16) in-depth semi-structured interviews with students and health care workers, as well as a focus group consisting of three (3) students aged between 20-60 years. This study used the Socio-Ecological Model and Health Belief Model as theoretical frameworks. Participants in the study identified both the barriers and the facilitators to the use of PrEP. The findings show that there is a lack of knowledge and low perception among students about PrEP. The study found that lack of knowledge was the source of the stigma and misconception about PrEP. Most participants expressed the need for more information to differentiate between the ARVs in PrEP and the ARV medication for HIV-positive people. However, they further expressed a willingness to embrace PrEP if they had information about it. The study highlights that the use of PrEP is linked to individual and environmental factors, which are crucial for PrEP roll-out. These factors include access to PrEP in a friendly manner, supportive family and friends, and the reduction of stigma and misconception. Therefore, when addressed, the said factors can foster the use of PrEP and mitigate barriers. For students to fully realise the benefits of HIV/AIDS prevention strategies like PrEP, there is a need for informed educational efforts. A well-informed student body is important for the successful adoption and use of PrEP. The findings suggest that the health care workers were knowledgeable and conscious about the use of PrEP. However, there were inconsistencies in the information provided by the health care workers regarding the recommended period for taking PrEP before testing again and taking the three-month course. The inconsistencies raise questions regarding the accuracy and reliability of the information provided. , Thesis (MSocSci) -- Faculty of Humanities, Sociology, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Lepelesana, Mamorena Sylvia
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/466150 , vital:76701
- Description: South Africa has the largest number of people living with HIV/AIDS compared to the rest of the world, with young people most at risk. The World Health Organisation (WHO) recommends the use of Pre-Exposure Prophylaxis (PrEP) in key populations at a higher risk of exposure to HIV/AIDS. The HIV/AIDS pandemic remains a pressing issue among higher education institutions, with a need for a comprehensive understanding of barriers and facilitators associated with the use of PrEP. The Higher Education AIDS (HEAIDS) plays a pivotal role in the mitigation of the spread of HIV/AIDS in Higher Education Institutions (HEIs). In this study, Rhodes University serves as a focal point for exploring PrEP implementation and acceptance. This qualitative study examines Rhodes University students' PrEP knowledge, perception, practice, and roll-out preference. More evidence is required to measure progress among students. A study was conducted involving sixteen (16) in-depth semi-structured interviews with students and health care workers, as well as a focus group consisting of three (3) students aged between 20-60 years. This study used the Socio-Ecological Model and Health Belief Model as theoretical frameworks. Participants in the study identified both the barriers and the facilitators to the use of PrEP. The findings show that there is a lack of knowledge and low perception among students about PrEP. The study found that lack of knowledge was the source of the stigma and misconception about PrEP. Most participants expressed the need for more information to differentiate between the ARVs in PrEP and the ARV medication for HIV-positive people. However, they further expressed a willingness to embrace PrEP if they had information about it. The study highlights that the use of PrEP is linked to individual and environmental factors, which are crucial for PrEP roll-out. These factors include access to PrEP in a friendly manner, supportive family and friends, and the reduction of stigma and misconception. Therefore, when addressed, the said factors can foster the use of PrEP and mitigate barriers. For students to fully realise the benefits of HIV/AIDS prevention strategies like PrEP, there is a need for informed educational efforts. A well-informed student body is important for the successful adoption and use of PrEP. The findings suggest that the health care workers were knowledgeable and conscious about the use of PrEP. However, there were inconsistencies in the information provided by the health care workers regarding the recommended period for taking PrEP before testing again and taking the three-month course. The inconsistencies raise questions regarding the accuracy and reliability of the information provided. , Thesis (MSocSci) -- Faculty of Humanities, Sociology, 2024
- Full Text:
- Date Issued: 2024-10-11
Suspicious sctivity reports: Enhancing the detection of terrorist financing and suspicious transactions in migrant remittances
- Authors: Mbiva, Stanley Munamato
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/465058 , vital:76569
- Description: Migrant remittances have become an important factor in poverty alleviation and microeconomic development in low-income nations. Global migrant remittances are expected to exceed US $630 billion by 2023, according to the World Bank. In addition to offering an alternate source of income that supplements the recipient’s household earnings, they are less likely to be affected by global economic downturns, ensuring stability and a consistent stream of revenue. However, the ease of global migrant remittance financial transfers has attracted the risk of being abused by terrorist organizations to quickly move and conceal operating cash, hence facilitating terrorist financing. This study aims to develop an unsupervised machine-learning model capable of detecting suspicious financial transactions associated with terrorist financing in migrant remittances. The data used in this study came from a World Bank survey of migrant remitters in Belgium. To understand the natural structures and grouping in the dataset, agglomerative hierarchical clustering and k-prototype clustering techniques were employed. This established the number of clusters present in the dataset making it possible to compare individual migrant remittances in the dataset with their peers. A Structural Equation Model (SEM) and an Local Outlier Factor - Isolation Forest (LOF-IF) algorithm were applied to analyze and detect suspicious transactions in the dataset. A traditional Rule-Based Method (RBM) was also created as a benchmark algorithm that evaluates model performance. The results show that the SEM model classifies a significantly high number of transactions as suspicious, making it prone to detecting false positives. Finally, the study applied the proposed ensemble outlier detection model to detect suspicious transactions in the same data set. The proposed ensemble model utilized an Isolation Forest (IF) for pruning and a Local Outlier Factor (LOF) to detect local outliers. The model performed exceptionally well, being able to detect over 90% of suspicious transactions in the testing data set during model cross-validation. , Thesis (MSc) -- Faculty of Science, Statistics, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Mbiva, Stanley Munamato
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/465058 , vital:76569
- Description: Migrant remittances have become an important factor in poverty alleviation and microeconomic development in low-income nations. Global migrant remittances are expected to exceed US $630 billion by 2023, according to the World Bank. In addition to offering an alternate source of income that supplements the recipient’s household earnings, they are less likely to be affected by global economic downturns, ensuring stability and a consistent stream of revenue. However, the ease of global migrant remittance financial transfers has attracted the risk of being abused by terrorist organizations to quickly move and conceal operating cash, hence facilitating terrorist financing. This study aims to develop an unsupervised machine-learning model capable of detecting suspicious financial transactions associated with terrorist financing in migrant remittances. The data used in this study came from a World Bank survey of migrant remitters in Belgium. To understand the natural structures and grouping in the dataset, agglomerative hierarchical clustering and k-prototype clustering techniques were employed. This established the number of clusters present in the dataset making it possible to compare individual migrant remittances in the dataset with their peers. A Structural Equation Model (SEM) and an Local Outlier Factor - Isolation Forest (LOF-IF) algorithm were applied to analyze and detect suspicious transactions in the dataset. A traditional Rule-Based Method (RBM) was also created as a benchmark algorithm that evaluates model performance. The results show that the SEM model classifies a significantly high number of transactions as suspicious, making it prone to detecting false positives. Finally, the study applied the proposed ensemble outlier detection model to detect suspicious transactions in the same data set. The proposed ensemble model utilized an Isolation Forest (IF) for pruning and a Local Outlier Factor (LOF) to detect local outliers. The model performed exceptionally well, being able to detect over 90% of suspicious transactions in the testing data set during model cross-validation. , Thesis (MSc) -- Faculty of Science, Statistics, 2024
- Full Text:
- Date Issued: 2024-10-11
Synthesis and biological evaluation of simple carboxylated chalcone and aurone derivatives
- Authors: Shauri, Thierry Lwanzo
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464576 , vital:76523
- Description: Restricted access. Expected release in 2026. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Shauri, Thierry Lwanzo
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464576 , vital:76523
- Description: Restricted access. Expected release in 2026. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
Taxonomy- and trait-based responses of chironomid assemblage structure to pollution in selected urban rivers, Eastern Cape, South Africa
- Authors: Osoh, Miracle Ogagaoghene
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466655 , vital:76764 , DOI https://doi.org/10.21504/10962/466655
- Description: Urbanisation, occasioned by an increasing human population and the proliferation of industries, is a major threat to freshwater resources and has been implicated as a cause of stream water quality deterioration, habitat degradation, and the loss of aquatic biodiversity. Pollution of freshwater systems resulting from urban-related activities severely alters stream ecosystem structure and function. To effectively protect and sustainably manage freshwater resources, it is important to develop biomonitoring tools which are both sensitive to changes in water quality conditions and can provide an understanding of the mechanisms by which urban pollution impacts freshwater ecosystems. In South Africa, the macroinvertebrate-based South African Scoring System version 5 (SASS5) is routinely used for water quality assessment. This tool is developed at the family level of taxonomic resolution, with the exception of a few taxa. This raises the question as to whether a species-level taxonomic approach, complemented with a trait-based approach could add additional value. This question was addressed comparatively by developing and applying a taxonomy- and trait-based approach using the taxonomically and functionally diverse Chironomidae family. Fifteen sites across three urban river systems (Buffalo, Bloukrans and Swartkops River systems) in the Eastern Cape Province of South Africa were purposefully selected for this study. Based on the predominant land use within the catchment of the sites and water quality variables, the study sites were grouped into five site categories. The least-impacted sites (REF) had 78.53% mean forested area, 5.98% mean urban area and 13.49% mean agricultural land. Sites that received diffuse pollution but were upstream from the effluent discharge point of wastewater treatment works (DP) had 59.07% mean forested area, 32.53% mean urban area and 6.20% mean agricultural land. Sites that received point source pollution from wastewater treatment works (PP) had 63.66% mean forested area, 26.26% mean urban area and 7.39% mean agricultural land. Sites further downstream from the wastewater treatment works that received impacts from both point source and diffuse pollution (AG) had 65.95% mean forested area, 18.24% mean urban area and 12.5% mean agricultural land. Sites selected for exploring the potential system recovery of the study rivers (RECV) had 77.21% mean forested area, 9.12% mean urban area and 10.7% mean agricultural land. Macroinvertebrates and physicochemical variables were sampled at sites in the Bloukrans and Buffalo rivers over four sampling events (spring, summer, winter, and autumn) between November 2021 and June 2022 using the SASS5 protocol. Historical chironomid and physicochemical data from the Swartkops River collected between 2009 and 2012 were also used in this study. The SASS5 family-level biotic index classified the water quality condition at the least impacted site (REF) of the Swartkops River as minimally impaired 80% of the time, compared to the chironomid-based multimetric index (CUMMI), which indicated that the water quality condition at this site was near-natural 50% of the time. The chironomid-based multimetric index and the SASS5 were divergent in their classification of water quality conditions at the DP and AG sites but were 100% in agreement regarding water quality conditions at the PP site as critically/severely modified. The SASS5 scores classified the water quality condition at the AG site as critically/severely modified 100% of the time, whereas the CUMMI index classified the water quality condition at this site as critically/severely modified 90% of the time but moderately modified 10% of the time. The results indicate that species-level and family-level indices tend to be in agreement for heavily impacted sites, but the same was not true for least or moderately impacted sites. Traits such as the possession of tracheal gills, very large body size, burrowing, whole-body undulation, construction of rigid tubes, possession of three tracheae, completion of lifecycle in more than one year, production of more than 1000 eggs per egg mass, preferences for fine detritus, and bivoltinism were deemed tolerant of urban pollution. Traits such as cuticular respiration, medium body size, predator feeding mode, completion of lifecycle within one year, and a preference for stone biotope were deemed sensitive to urban pollution. An approach was developed to classify chironomids into those that are potentially vulnerable and those that are resilient to urban pollution. The abundances of vulnerable species correlated positively with increasing dissolved oxygen and negatively with increasing turbidity, electrical conductivity, nitrite-nitrogen, ammonium-nitrogen, and orthophosphate-phosphorus. The relative abundance of the highly vulnerable species and that of the highly tolerant species responded significantly to urban pollution and differentiated between the site categories. The relative abundance of the highly vulnerable species was significantly different between the DP and PP site categories. The richness of vulnerable and highly vulnerable species was significantly different between the REF sites and the impacted site categories (DP, PP, and AG). These results indicated that the developed approach successfully predicted chironomid responses to urban pollution. Overall, the study makes important contributions to the field of freshwater biomonitoring. First, the study highlighted that species-level identification is necessary to differentiate sites which may be considered moderately impacted. Both family and species-level tools were sensitive to water quality conditions for least impacted and highly impacted sites, but the differences between the family-level and species-level indices were pronounced for sites considered moderately impacted. Second, a trait-based approach provided a mechanism for developing predictive tools, and in the case of this study, the potential resilience or vulnerability of chironomids was reliably predicted. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Osoh, Miracle Ogagaoghene
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466655 , vital:76764 , DOI https://doi.org/10.21504/10962/466655
- Description: Urbanisation, occasioned by an increasing human population and the proliferation of industries, is a major threat to freshwater resources and has been implicated as a cause of stream water quality deterioration, habitat degradation, and the loss of aquatic biodiversity. Pollution of freshwater systems resulting from urban-related activities severely alters stream ecosystem structure and function. To effectively protect and sustainably manage freshwater resources, it is important to develop biomonitoring tools which are both sensitive to changes in water quality conditions and can provide an understanding of the mechanisms by which urban pollution impacts freshwater ecosystems. In South Africa, the macroinvertebrate-based South African Scoring System version 5 (SASS5) is routinely used for water quality assessment. This tool is developed at the family level of taxonomic resolution, with the exception of a few taxa. This raises the question as to whether a species-level taxonomic approach, complemented with a trait-based approach could add additional value. This question was addressed comparatively by developing and applying a taxonomy- and trait-based approach using the taxonomically and functionally diverse Chironomidae family. Fifteen sites across three urban river systems (Buffalo, Bloukrans and Swartkops River systems) in the Eastern Cape Province of South Africa were purposefully selected for this study. Based on the predominant land use within the catchment of the sites and water quality variables, the study sites were grouped into five site categories. The least-impacted sites (REF) had 78.53% mean forested area, 5.98% mean urban area and 13.49% mean agricultural land. Sites that received diffuse pollution but were upstream from the effluent discharge point of wastewater treatment works (DP) had 59.07% mean forested area, 32.53% mean urban area and 6.20% mean agricultural land. Sites that received point source pollution from wastewater treatment works (PP) had 63.66% mean forested area, 26.26% mean urban area and 7.39% mean agricultural land. Sites further downstream from the wastewater treatment works that received impacts from both point source and diffuse pollution (AG) had 65.95% mean forested area, 18.24% mean urban area and 12.5% mean agricultural land. Sites selected for exploring the potential system recovery of the study rivers (RECV) had 77.21% mean forested area, 9.12% mean urban area and 10.7% mean agricultural land. Macroinvertebrates and physicochemical variables were sampled at sites in the Bloukrans and Buffalo rivers over four sampling events (spring, summer, winter, and autumn) between November 2021 and June 2022 using the SASS5 protocol. Historical chironomid and physicochemical data from the Swartkops River collected between 2009 and 2012 were also used in this study. The SASS5 family-level biotic index classified the water quality condition at the least impacted site (REF) of the Swartkops River as minimally impaired 80% of the time, compared to the chironomid-based multimetric index (CUMMI), which indicated that the water quality condition at this site was near-natural 50% of the time. The chironomid-based multimetric index and the SASS5 were divergent in their classification of water quality conditions at the DP and AG sites but were 100% in agreement regarding water quality conditions at the PP site as critically/severely modified. The SASS5 scores classified the water quality condition at the AG site as critically/severely modified 100% of the time, whereas the CUMMI index classified the water quality condition at this site as critically/severely modified 90% of the time but moderately modified 10% of the time. The results indicate that species-level and family-level indices tend to be in agreement for heavily impacted sites, but the same was not true for least or moderately impacted sites. Traits such as the possession of tracheal gills, very large body size, burrowing, whole-body undulation, construction of rigid tubes, possession of three tracheae, completion of lifecycle in more than one year, production of more than 1000 eggs per egg mass, preferences for fine detritus, and bivoltinism were deemed tolerant of urban pollution. Traits such as cuticular respiration, medium body size, predator feeding mode, completion of lifecycle within one year, and a preference for stone biotope were deemed sensitive to urban pollution. An approach was developed to classify chironomids into those that are potentially vulnerable and those that are resilient to urban pollution. The abundances of vulnerable species correlated positively with increasing dissolved oxygen and negatively with increasing turbidity, electrical conductivity, nitrite-nitrogen, ammonium-nitrogen, and orthophosphate-phosphorus. The relative abundance of the highly vulnerable species and that of the highly tolerant species responded significantly to urban pollution and differentiated between the site categories. The relative abundance of the highly vulnerable species was significantly different between the DP and PP site categories. The richness of vulnerable and highly vulnerable species was significantly different between the REF sites and the impacted site categories (DP, PP, and AG). These results indicated that the developed approach successfully predicted chironomid responses to urban pollution. Overall, the study makes important contributions to the field of freshwater biomonitoring. First, the study highlighted that species-level identification is necessary to differentiate sites which may be considered moderately impacted. Both family and species-level tools were sensitive to water quality conditions for least impacted and highly impacted sites, but the differences between the family-level and species-level indices were pronounced for sites considered moderately impacted. Second, a trait-based approach provided a mechanism for developing predictive tools, and in the case of this study, the potential resilience or vulnerability of chironomids was reliably predicted. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2024
- Full Text:
- Date Issued: 2024-10-11
Teachers’ use of authentic tasks through mathematics trails in a mobile learning environment to facilitate conceptual teaching
- Authors: Matengu, Given Kahale
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466429 , vital:76727 , DOI https://doi.org/10.21504/10962/466429
- Description: The teaching and learning of mathematics in Namibia is confronted by various forms of challenges that require continuous search for effective pedagogical strategies and approaches to enhance mathematical understanding. Some of the ways include using real and authentic outdoor activities and technological tools, such as smartphones, for teaching and learning purposes. The need to use authentic and realistic tasks in outdoor settings in the teaching of mathematics has strong support from the literature. Moreover, many recent reforms in education challenge teachers across all subjects to use modern and up-to-date technologies to complement and support existing approaches to teaching. Smartphones, in particular, offer new opportunities in the evolution of technology-enhanced learning by allowing teaching and learning to occur in authentic and realistic contexts that extend to real-life environments. This qualitative case study proposes a practical framework that can facilitate mathematical understanding in teaching through the implementation of authentic and realistic outdoor tasks by using the Math City Map (MCM) project on a smartphone. The study aims to analyse and understand how mathematics teachers can create and implement authentic and realistic tasks in an outdoor mathematics trail to facilitate the conceptual teaching of area, volume, ratio and proportion topics, within the context of the Realistic Mathematics Education theory (RME). The study is framed within the RME theory and the iPAC (personalisation, authenticity, collaboration) mobile pedagogical framework. The research process is underpinned by an interpretivist paradigm. Data was collected from eight selected teachers through observations and interviews and analysed using frameworks derived from the RME and iPAC mobile pedagogical theories and the emergence of common themes. The findings suggest that the integration of smartphones and mathematics trails have pedagogical benefits in mathematics teaching and can facilitate the use of outdoor tasks that are connected to learners’ realities. The study argues that while MCM mathematics trail tasks can be difficult to create, it was worthwhile for teachers using them to conceptually teach the selected topics. It is therefore hoped that the findings of this study contribute towards the use of outdoor mathematics trails and smartphones in the teaching of mathematics. , Thesis (PhD) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Matengu, Given Kahale
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466429 , vital:76727 , DOI https://doi.org/10.21504/10962/466429
- Description: The teaching and learning of mathematics in Namibia is confronted by various forms of challenges that require continuous search for effective pedagogical strategies and approaches to enhance mathematical understanding. Some of the ways include using real and authentic outdoor activities and technological tools, such as smartphones, for teaching and learning purposes. The need to use authentic and realistic tasks in outdoor settings in the teaching of mathematics has strong support from the literature. Moreover, many recent reforms in education challenge teachers across all subjects to use modern and up-to-date technologies to complement and support existing approaches to teaching. Smartphones, in particular, offer new opportunities in the evolution of technology-enhanced learning by allowing teaching and learning to occur in authentic and realistic contexts that extend to real-life environments. This qualitative case study proposes a practical framework that can facilitate mathematical understanding in teaching through the implementation of authentic and realistic outdoor tasks by using the Math City Map (MCM) project on a smartphone. The study aims to analyse and understand how mathematics teachers can create and implement authentic and realistic tasks in an outdoor mathematics trail to facilitate the conceptual teaching of area, volume, ratio and proportion topics, within the context of the Realistic Mathematics Education theory (RME). The study is framed within the RME theory and the iPAC (personalisation, authenticity, collaboration) mobile pedagogical framework. The research process is underpinned by an interpretivist paradigm. Data was collected from eight selected teachers through observations and interviews and analysed using frameworks derived from the RME and iPAC mobile pedagogical theories and the emergence of common themes. The findings suggest that the integration of smartphones and mathematics trails have pedagogical benefits in mathematics teaching and can facilitate the use of outdoor tasks that are connected to learners’ realities. The study argues that while MCM mathematics trail tasks can be difficult to create, it was worthwhile for teachers using them to conceptually teach the selected topics. It is therefore hoped that the findings of this study contribute towards the use of outdoor mathematics trails and smartphones in the teaching of mathematics. , Thesis (PhD) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-10-11
Teaching problem solving: the "Ten Commandments" approach
- Authors: Matiwane, Noluvuyo
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464897 , vital:76555
- Description: The evident need for an intervention to help physics students, especially incoming university students, develop their problem-solving skills led to exploring possible curriculum structures to achieve the goal. A modified curriculum structure of the first-year physics course, including explicit teaching of physics problem solving, was developed and implemented at Rhodes University, South Africa, in 2017. First-year physics students learn to solve problems by implementing the "Ten Commandments" of physics problem solving in their solutions, following a three-stage problem-solving framework. Additionally, students attend whiteboard tutorial sessions where they actively practise using the problem-solving framework in their solutions to physics problems with peers in an environment where help is available. Students are explicitly prompted to use the \Ten Commandments" during the whiteboard tutorials and not prompted for other assessment tasks. Students' solutions to formative physics assessment tasks (problem sets and tests) in the first semester were examined, problem-solving scores were determined using a problem-solving rubric developed in the department, shifts in attitudes and beliefs about physics and solving problems in physics were measured, and relationships between their problem-solving scores and task performance were evaluated to investigate how students adopted the framework and its implications over one semester. The problems issued to students differed in context and difficulty level; as a result, not all of the "Ten Commandments" were applicable to solve all problems, and different combinations of the commandments were applied to different problems. The explicit use of the problem-solving rubric to mark student problem sets was an indirect prompt for students to use commandments when doing their problem sets. As a result, students attempted to implement more applicable "commandments" (mostly partially correct) in their solutions to problem sets than in tests. Moreover, students' solutions to problems show that they used more of the "commandments" they were familiar with from school and less of the new ones, such as drawing diagrams without being prompted, producing algebraic solutions before substituting numbers, and doing dimensional analysis. Problem sets are often assumed to help prepare students for tests; however, correlations between students' problem-solving scores and performance between the two assessments did not give clear indications of whether problem sets were helping to prepare students to solve problems. Lastly, students' attitudes and beliefs also show a negative shift in students' perceptions of problem-solving by the end of the first semester. Problem-solving is a skill that develops in stages and over time; therefore, a timeframe longer than one semester is needed to report on significant changes in students' problem-solving habits and perspectives about problem-solving in physics. The study results are also important in giving insights into the initial developments of problem-solving skills and teaching problem solving. , Thesis (MSc) -- Faculty of Science, Physics and Electronics, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Matiwane, Noluvuyo
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464897 , vital:76555
- Description: The evident need for an intervention to help physics students, especially incoming university students, develop their problem-solving skills led to exploring possible curriculum structures to achieve the goal. A modified curriculum structure of the first-year physics course, including explicit teaching of physics problem solving, was developed and implemented at Rhodes University, South Africa, in 2017. First-year physics students learn to solve problems by implementing the "Ten Commandments" of physics problem solving in their solutions, following a three-stage problem-solving framework. Additionally, students attend whiteboard tutorial sessions where they actively practise using the problem-solving framework in their solutions to physics problems with peers in an environment where help is available. Students are explicitly prompted to use the \Ten Commandments" during the whiteboard tutorials and not prompted for other assessment tasks. Students' solutions to formative physics assessment tasks (problem sets and tests) in the first semester were examined, problem-solving scores were determined using a problem-solving rubric developed in the department, shifts in attitudes and beliefs about physics and solving problems in physics were measured, and relationships between their problem-solving scores and task performance were evaluated to investigate how students adopted the framework and its implications over one semester. The problems issued to students differed in context and difficulty level; as a result, not all of the "Ten Commandments" were applicable to solve all problems, and different combinations of the commandments were applied to different problems. The explicit use of the problem-solving rubric to mark student problem sets was an indirect prompt for students to use commandments when doing their problem sets. As a result, students attempted to implement more applicable "commandments" (mostly partially correct) in their solutions to problem sets than in tests. Moreover, students' solutions to problems show that they used more of the "commandments" they were familiar with from school and less of the new ones, such as drawing diagrams without being prompted, producing algebraic solutions before substituting numbers, and doing dimensional analysis. Problem sets are often assumed to help prepare students for tests; however, correlations between students' problem-solving scores and performance between the two assessments did not give clear indications of whether problem sets were helping to prepare students to solve problems. Lastly, students' attitudes and beliefs also show a negative shift in students' perceptions of problem-solving by the end of the first semester. Problem-solving is a skill that develops in stages and over time; therefore, a timeframe longer than one semester is needed to report on significant changes in students' problem-solving habits and perspectives about problem-solving in physics. The study results are also important in giving insights into the initial developments of problem-solving skills and teaching problem solving. , Thesis (MSc) -- Faculty of Science, Physics and Electronics, 2024
- Full Text:
- Date Issued: 2024-10-11
Technological pedagogical content knowledge: an examination of rural secondary school life sciences teachers’ integration of technology in Eastern Cape province
- Authors: Shambare, Brian
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466458 , vital:76730 , DOI https://doi.org/10.21504/10962/466458
- Description: Rural education, particularly in the Global South, faces distinct challenges flowing from low socio-economic conditions, limited resources, and inadequate funding. These issues notably affect rural teachers’ abilities to deliver quality education. Although technology integration offers potential benefits and rural teachers have increased access to various technologies, they frequently adopt these tools spontaneously without guidelines. While many teachers in rural schools choose specific technologies to address teaching challenges, technology has to be integrated with a clear pedagogical intent. The rural teachers’ frequent adoption of technologies hints at technological pedagogical content knowledge (TPACK) development, consciously or unconsciously. However, the process of developing this expertise remains largely unknown. Furthermore, the development of TPACK among teachers in rural Global South schools, particularly those who did not receive formal or informal technology training during their initial teacher education or professional development, remains unclear. Therefore, this research delved into the practices, factors, and experiences influencing the development of TPACK, all from the perspective of Life Sciences teachers in rural schools. The voices of teachers in rural regions have been notably absent in the broader discourse of TPACK research, making the current study’s insights particularly significant. This qualitative and investigative study, located within the interpretivist paradigm, is grounded in Vygotsky’s (1978) socio-cultural theory and Koehler and Mishra’s (2006) Technological Pedagogical Content Knowledge framework. Seven Life Sciences teachers participated in the study. The teacher participants were purposively sampled from schools in the Joe Gqabi district in the Eastern Cape province of South Africa. Multiple data-generation instruments were employed. These included a questionnaire, semi-structured interviews, lesson observations, and sharing circle discussions. A thematic analysis approach, guided by the study’s dual theoretical perspective, was applied to dissect and analyse the data. The study’s findings challenged the prevailing assumption that rural schools lack access to technological resources, unveiling that rural Life Sciences teachers in this research had access to diverse educational technologies. Nevertheless, despite improved technology accessibility, these teachers predominantly employed ‘simple skill-based’ technologies for content delivery, resulting in limited learner engagement. Notwithstanding the challenges posed by inadequate school infrastructure, limited electricity access, and poor Internet connectivity, this investigation found that Life Sciences teachers in rural settings who lack formal technology integration training demonstrated enthusiasm for incorporating technology into their teaching methods. Furthermore, these teachers exhibited strength in non-technological TPACK domains, such as content knowledge (CK), pedagogical knowledge (PK), and pedagogical content knowledge (PCK), while demonstrating limited expertise in technology-related domains, such as technological knowledge (TK), technological pedagogical knowledge (TPK), and technological pedagogical content knowledge (TPACK). The study uncovered nuanced factors, practices, and experiences contributing to TPACK development among rural Life Sciences teachers. These include learning from their learners, collaborating with peers, and engaging in self-directed learning. The study also proposed a new theoretical perspective to the existing TPACK framework to cater for technology integration in rural school contexts. Overall, this research provided a unique perspective on TPACK development in rural schools, particularly in the Global South. The study recommended targeted investments in professional development, promoting peer collaboration, and fostering a culture of self-directed learning. Furthermore, the current research emphasised the importance of recognising the evolving educational landscape as a two-way knowledge exchange between teachers and learners to foster TPACK development in rural schools. , Thesis (PhD) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Shambare, Brian
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466458 , vital:76730 , DOI https://doi.org/10.21504/10962/466458
- Description: Rural education, particularly in the Global South, faces distinct challenges flowing from low socio-economic conditions, limited resources, and inadequate funding. These issues notably affect rural teachers’ abilities to deliver quality education. Although technology integration offers potential benefits and rural teachers have increased access to various technologies, they frequently adopt these tools spontaneously without guidelines. While many teachers in rural schools choose specific technologies to address teaching challenges, technology has to be integrated with a clear pedagogical intent. The rural teachers’ frequent adoption of technologies hints at technological pedagogical content knowledge (TPACK) development, consciously or unconsciously. However, the process of developing this expertise remains largely unknown. Furthermore, the development of TPACK among teachers in rural Global South schools, particularly those who did not receive formal or informal technology training during their initial teacher education or professional development, remains unclear. Therefore, this research delved into the practices, factors, and experiences influencing the development of TPACK, all from the perspective of Life Sciences teachers in rural schools. The voices of teachers in rural regions have been notably absent in the broader discourse of TPACK research, making the current study’s insights particularly significant. This qualitative and investigative study, located within the interpretivist paradigm, is grounded in Vygotsky’s (1978) socio-cultural theory and Koehler and Mishra’s (2006) Technological Pedagogical Content Knowledge framework. Seven Life Sciences teachers participated in the study. The teacher participants were purposively sampled from schools in the Joe Gqabi district in the Eastern Cape province of South Africa. Multiple data-generation instruments were employed. These included a questionnaire, semi-structured interviews, lesson observations, and sharing circle discussions. A thematic analysis approach, guided by the study’s dual theoretical perspective, was applied to dissect and analyse the data. The study’s findings challenged the prevailing assumption that rural schools lack access to technological resources, unveiling that rural Life Sciences teachers in this research had access to diverse educational technologies. Nevertheless, despite improved technology accessibility, these teachers predominantly employed ‘simple skill-based’ technologies for content delivery, resulting in limited learner engagement. Notwithstanding the challenges posed by inadequate school infrastructure, limited electricity access, and poor Internet connectivity, this investigation found that Life Sciences teachers in rural settings who lack formal technology integration training demonstrated enthusiasm for incorporating technology into their teaching methods. Furthermore, these teachers exhibited strength in non-technological TPACK domains, such as content knowledge (CK), pedagogical knowledge (PK), and pedagogical content knowledge (PCK), while demonstrating limited expertise in technology-related domains, such as technological knowledge (TK), technological pedagogical knowledge (TPK), and technological pedagogical content knowledge (TPACK). The study uncovered nuanced factors, practices, and experiences contributing to TPACK development among rural Life Sciences teachers. These include learning from their learners, collaborating with peers, and engaging in self-directed learning. The study also proposed a new theoretical perspective to the existing TPACK framework to cater for technology integration in rural school contexts. Overall, this research provided a unique perspective on TPACK development in rural schools, particularly in the Global South. The study recommended targeted investments in professional development, promoting peer collaboration, and fostering a culture of self-directed learning. Furthermore, the current research emphasised the importance of recognising the evolving educational landscape as a two-way knowledge exchange between teachers and learners to foster TPACK development in rural schools. , Thesis (PhD) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-10-11
The acceptability of Prolonged Exposure Therapy for Primary Care (PE-PC) for the treatment of PTSD in a low resourced community in the Eastern Cape
- Authors: Leboho, Lerato
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/466191 , vital:76706
- Description: Post-traumatic stress disorder (PTSD) is a global mental health concern, especially in low- resourced communities that are characterised by limited access to health professionals, limited healthcare infrastructure, and limited access to evidence-based mental healthcare at primary care level. Over the last decade, several psychological trauma-focused therapies (TFTs), such as prolonged exposure therapy (PE) have been developed to treat PTSD. In the context of the existing literature, studies done in HICs have explored the implementation and acceptability of prolonged exposure therapy at primary care level (PE-PC) as a first-line treatment for PTSD. Contrary to this, there is little to no implementation studies done to date that have examined the acceptability of empirically supported treatments (ESTs), such as PE in low-resourced countries, such as South Africa. Using the Implementation Science framework, ten participants were recruited to be interviewed, using semi-structured interviews, about their experiences and perceptions of PE-PC as a treatment for PTSD, and to also share their experiences of living with PTSD. The interview data was analysed using the reflexive thematic analysis (RTA) method to determine whether PE-PC is an acceptable treatment for PTSD that can be administered at community level and highlights the importance of integrating mental health within primary healthcare practice. Based on the analysis four superordinate themes were identified, namely, lack and absence of social support; factors preventing trauma survivors from accessing EBTs; lack of knowledge regarding mental health literacy, and adaptation of a brief trauma-focused therapy in a low-resource community. The evidence this study shows that some of the factors that hinder the acceptability of trauma-focused therapies (TFTs) at community level, include stigma and discrimination, the absence of social support, limited resources, and inadequate knowledge on mental health and illness. Therefore, it makes sense of the urgency to implement evidence-based treatments (EBTs) in LMICs. Findings of this thesis suggest that (a) PE-PC should be adopted at community level, and that (b) PE-PC is an acceptable treatment for PTSD in low-resourced communities. , Thesis (MSocSci) -- Faculty of Humanities, Psychology, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Leboho, Lerato
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/466191 , vital:76706
- Description: Post-traumatic stress disorder (PTSD) is a global mental health concern, especially in low- resourced communities that are characterised by limited access to health professionals, limited healthcare infrastructure, and limited access to evidence-based mental healthcare at primary care level. Over the last decade, several psychological trauma-focused therapies (TFTs), such as prolonged exposure therapy (PE) have been developed to treat PTSD. In the context of the existing literature, studies done in HICs have explored the implementation and acceptability of prolonged exposure therapy at primary care level (PE-PC) as a first-line treatment for PTSD. Contrary to this, there is little to no implementation studies done to date that have examined the acceptability of empirically supported treatments (ESTs), such as PE in low-resourced countries, such as South Africa. Using the Implementation Science framework, ten participants were recruited to be interviewed, using semi-structured interviews, about their experiences and perceptions of PE-PC as a treatment for PTSD, and to also share their experiences of living with PTSD. The interview data was analysed using the reflexive thematic analysis (RTA) method to determine whether PE-PC is an acceptable treatment for PTSD that can be administered at community level and highlights the importance of integrating mental health within primary healthcare practice. Based on the analysis four superordinate themes were identified, namely, lack and absence of social support; factors preventing trauma survivors from accessing EBTs; lack of knowledge regarding mental health literacy, and adaptation of a brief trauma-focused therapy in a low-resource community. The evidence this study shows that some of the factors that hinder the acceptability of trauma-focused therapies (TFTs) at community level, include stigma and discrimination, the absence of social support, limited resources, and inadequate knowledge on mental health and illness. Therefore, it makes sense of the urgency to implement evidence-based treatments (EBTs) in LMICs. Findings of this thesis suggest that (a) PE-PC should be adopted at community level, and that (b) PE-PC is an acceptable treatment for PTSD in low-resourced communities. , Thesis (MSocSci) -- Faculty of Humanities, Psychology, 2024
- Full Text:
- Date Issued: 2024-10-11
The adaptation of non-standard labour markets and their spatial distribution: the effects and legacies of COVID-19 on South Africa’s freelance creative workers
- Authors: Drummond, Fiona Jane
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466350 , vital:76720
- Description: Access restricted. Expected release in 2026. , Thesis (PhD) -- Faculty of Commerce, Economics and Economic History, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Drummond, Fiona Jane
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466350 , vital:76720
- Description: Access restricted. Expected release in 2026. , Thesis (PhD) -- Faculty of Commerce, Economics and Economic History, 2024
- Full Text:
- Date Issued: 2024-10-11
The Amadiba Crisis Committee: sustaining mobilisation in Xolobeni, South Africa
- Authors: Nowicki, Lucas Joel
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/466027 , vital:76678
- Description: This thesis seeks to understand how the Amadiba Crisis Committee (ACC), a rural movement from Xolobeni, has sustained mobilisation and worked with allies in civil society. The ACC was formed in 2007 in response to attempts by a mining company, Transworld Energy and Mineral Resources (TEM), to establish a sand mine off the coast of the Eastern Cape of South Africa. Since 2007, the ACC has achieved significant victories in their fight against imposed development projects they argue threaten existing livelihoods that rely on the land. This thesis theorises the ACC’s mobilisation by drawing on concepts such as political opportunity, resource mobilisation, repertoires of action, framing and resource frontiers’. The thesis responds to the research question(s) by undertaking a thematic analysis of textual data drawn from semi-structured in-depth interviews conducted with ACC members and their allies in civil society, most of which were collected during fieldwork in Xolobeni. The study finds that the ACC has sustained mobilisation through the combination of more public and institutional repertoires of action with more subtle everyday forms of resistance. These repertoires include dynamic uses of the law and rights discourses to further the movement’s goals. The ACC also used more confrontational tactics whereby activists use their bodies to physically disrupt extractive projects’ operations, actions which are coordinated through communication networks and local leadership structures. Furthermore, the ACC promotes alternative development strategies in a way which can be conceived as a type of prefigurative politics whereby activists actualise and embody the types of relations and development they want to see in the world. Many of these tactics were supported and made possible due to the presence of allies in civil society such as Sustaining the Wild Coast (SWC). Although there is a risk that such allies may end up co-opting and undermining mobilisation, this risk has been averted because both the SWC and the ACC are committed to maintaining separation between the movement and NGO in mobilisation. The SWC’s support has included facilitating access to media and civil society networks located in urban areas and using these networks and social capital to access information and other necessary resources. Overall, the movement has sustained resistance to imposed development projects by drawing on strong existing historical community ties, using diverse repertoires to achieve goals and build the movement’s base, and by consistently outlining alternative development strategies as a positive vision to their mobilisation. This has consolidated the ACC as a movement and established them as a powerful force with the ability to shape local development, policy and public discourse. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Nowicki, Lucas Joel
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/466027 , vital:76678
- Description: This thesis seeks to understand how the Amadiba Crisis Committee (ACC), a rural movement from Xolobeni, has sustained mobilisation and worked with allies in civil society. The ACC was formed in 2007 in response to attempts by a mining company, Transworld Energy and Mineral Resources (TEM), to establish a sand mine off the coast of the Eastern Cape of South Africa. Since 2007, the ACC has achieved significant victories in their fight against imposed development projects they argue threaten existing livelihoods that rely on the land. This thesis theorises the ACC’s mobilisation by drawing on concepts such as political opportunity, resource mobilisation, repertoires of action, framing and resource frontiers’. The thesis responds to the research question(s) by undertaking a thematic analysis of textual data drawn from semi-structured in-depth interviews conducted with ACC members and their allies in civil society, most of which were collected during fieldwork in Xolobeni. The study finds that the ACC has sustained mobilisation through the combination of more public and institutional repertoires of action with more subtle everyday forms of resistance. These repertoires include dynamic uses of the law and rights discourses to further the movement’s goals. The ACC also used more confrontational tactics whereby activists use their bodies to physically disrupt extractive projects’ operations, actions which are coordinated through communication networks and local leadership structures. Furthermore, the ACC promotes alternative development strategies in a way which can be conceived as a type of prefigurative politics whereby activists actualise and embody the types of relations and development they want to see in the world. Many of these tactics were supported and made possible due to the presence of allies in civil society such as Sustaining the Wild Coast (SWC). Although there is a risk that such allies may end up co-opting and undermining mobilisation, this risk has been averted because both the SWC and the ACC are committed to maintaining separation between the movement and NGO in mobilisation. The SWC’s support has included facilitating access to media and civil society networks located in urban areas and using these networks and social capital to access information and other necessary resources. Overall, the movement has sustained resistance to imposed development projects by drawing on strong existing historical community ties, using diverse repertoires to achieve goals and build the movement’s base, and by consistently outlining alternative development strategies as a positive vision to their mobilisation. This has consolidated the ACC as a movement and established them as a powerful force with the ability to shape local development, policy and public discourse. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2024
- Full Text:
- Date Issued: 2024-10-11
The art of adaption: the National Arts Festival’s strategic response to the COVID-19 pandemic
- Authors: Brody, Blake Benjamin
- Date: 2024-10-11
- Subjects: Standard Bank National Arts Festival , Strategic planning , Strategic thinking , Crisis management South Africa , Business model , Stakeholder management , COVID-19 Pandemic, 2020- Influence
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/461863 , vital:76246
- Description: The National Arts Festival (NAF), an annual event held in South Africa, faced a significant challenge in 2020 due to the COVID-19 pandemic. The traditional in-person format of the festival was no longer feasible due to government restrictions. In response, the NAF's CEO, Monica Newton, led her team in a rapid transition to a virtual platform. This decision-making process and the creation of the first virtual NAF (vNAF) occurred within a remarkably short period of 100 days. This teaching case study delves into the academic framework of crisis management, stakeholder theory, strategic thinking, strategic management, and business models, examining their application in the context of the NAF's transformation. To understand the decision-making process and challenges faced by the NAF, a qualitative research design was employed. Data collection involved two face-to-face interviews with Monica Newton, CEO of the NAF, and secondary sources. The teaching case is accompanied by a comprehensive note for educators, offering guidance on its classroom use. The note includes a case synopsis, intended audience, suggested learning outcomes, theoretical connections, teaching strategies, potential discussion questions, evaluation methods, and additional resources. It supports a multi-faceted analysis of the NAF's transformation and encourages vibrant class discussion. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Brody, Blake Benjamin
- Date: 2024-10-11
- Subjects: Standard Bank National Arts Festival , Strategic planning , Strategic thinking , Crisis management South Africa , Business model , Stakeholder management , COVID-19 Pandemic, 2020- Influence
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/461863 , vital:76246
- Description: The National Arts Festival (NAF), an annual event held in South Africa, faced a significant challenge in 2020 due to the COVID-19 pandemic. The traditional in-person format of the festival was no longer feasible due to government restrictions. In response, the NAF's CEO, Monica Newton, led her team in a rapid transition to a virtual platform. This decision-making process and the creation of the first virtual NAF (vNAF) occurred within a remarkably short period of 100 days. This teaching case study delves into the academic framework of crisis management, stakeholder theory, strategic thinking, strategic management, and business models, examining their application in the context of the NAF's transformation. To understand the decision-making process and challenges faced by the NAF, a qualitative research design was employed. Data collection involved two face-to-face interviews with Monica Newton, CEO of the NAF, and secondary sources. The teaching case is accompanied by a comprehensive note for educators, offering guidance on its classroom use. The note includes a case synopsis, intended audience, suggested learning outcomes, theoretical connections, teaching strategies, potential discussion questions, evaluation methods, and additional resources. It supports a multi-faceted analysis of the NAF's transformation and encourages vibrant class discussion. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2024
- Full Text:
- Date Issued: 2024-10-11
The assessment of abandoned cultivated lands: a case study of Lower Tsitsana and Hlankomo villages in the Tsitsa River catchment, Eastern Cape, South Africa
- Authors: Dakie, Regina Nokufa
- Date: 2024-10-11
- Subjects: Agricultural land , Grasslands South Africa Eastern Cape , Abandoned land , Social ecology , Aerial photography
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464787 , vital:76545
- Description: Globally, agriculture is an essential part of people’s livelihoods, contributing to rural economies and food security. However, cultivated land abandonment, the intentional or unintentional cessation of agricultural activities for takeover by other land uses, is becoming increasingly common. Although widely studied, the outcomes of cultivated land abandonment are highly context-dependent and varied. Understanding this phenomenon would thus benefit from placed-based social-ecological case study perspectives, particularly in more understudied contexts. This study represents such a perspective, taking a social-ecological approach to understand how land abandonment has emerged and what its consequences are for the desired future outcomes in the Hlankomo and Lower Tsitsana villages in the Tsitsa River catchment. Drawing on McGinnis & Ostrom’s (2009) framework, I framed cultivated land abandonment in my study area as a “focal action situation” informed by the interaction of natural resource systems, governance systems, actors, and resource units. To better understand the current state of the natural resource system and important ecological (resource) units (grass), I used two measures of ecological condition: a rapid assessment test that provided a broad, if superficial, understanding of degradation and land condition, and a veld condition assessment that provided an understanding of grassland composition and quality in abandoned fields. I also used aerial photographs to assess the extent of changes in abandoned cultivation in the catchment. To understand actors, governance systems, how they interacted with natural resource systems and units for land abandonment to emerge, and what implications these interactions may have for the future of these lands, I used semi-structured interviews. The Rapid Assessment Test tool showed that the abandoned cultivated fields were dominated by grasses (58.3%), while shrubs (11%) and succulents (11%) were the least prevalent. The veld assessment identified sixteen grass species in both villages, with Aristida junciformis (23%) and Eragrostis plana (22.2 %) being the most dominant. The grazing statuses of the grasses showed that there were more Increaser II species, followed by Increaser III, Exotic, Increaser I and Decreaser species, respectively. There were more grass species with low grazing and average grazing values than grass species with high grazing values. The Rapid Assessment tool and the Veld assessment showed that the fields were dominated by poor grass species that grow on degraded lands. The results thus showed that the abandoned cultivated lands are degraded and in poor condition, as they are covered mainly by poor grass species that are dominant in over-utilised and overgrazed areas. The aerial photographs showed a decline in cultivated lands from 1966 to 2015, with a significant decline between 1966 and 2003. The land under cultivation between 1966 and 2003 decreased by 95 %, resulting in an annual decline of 2.56 %. The land under cultivation from 2003 and 2015 decreased by 60 %, resulting in a decline of 4 % per year. Local people corroborated the increase in cultivated land abandonment in the interviews, and this is why I attempt to understand why abandoned cultivated land happened (how the resource system and governance systems/actors interacted to shape cultivated land abandonment). As in other South African rural contexts, reasons people gave for land cultivation abandonment revealed the strongly intertwined nature of ecological and social systems, including no fence, livestock eating crops, no cattle, lack of labour, migration, lack of resources (money and equipment), parents passing on, expensive fertilizers, rainfall variability, dependency on grants, lack of interest and laziness. People had different views about the future of the abandoned cultivated lands, suggesting building homes, recreational parks, poultry farms, and recultivating and livestock protection camps, while others indicated that they didn’t care what happens to the abandoned fields. Many people still value abandoned lands and would prefer for the land to be recultivated, but they are held back by factors beyond their control, such as no fencing and a lack of governmental support in the form of fertilisers and machinery for ploughing. Additionally, our ecological results suggest that, due to the degraded states of these lands, significant rehabilitation would be required to realize these desired outcomes. Overall, this study shows the social-ecological complexity that drives cultivated land abandonment in the Tsitsa River catchment, providing a context-specific understanding of the drivers and consequences of abandoned cultivated land, future options more specific to these villages, and the broader Tsitsa catchment. At the same time, my study also corroborates similar studies in rural African and other global South contexts, thus supporting generalizable knowledge that can be used in the development of agrarian, social and environmental policies in these regions. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Dakie, Regina Nokufa
- Date: 2024-10-11
- Subjects: Agricultural land , Grasslands South Africa Eastern Cape , Abandoned land , Social ecology , Aerial photography
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464787 , vital:76545
- Description: Globally, agriculture is an essential part of people’s livelihoods, contributing to rural economies and food security. However, cultivated land abandonment, the intentional or unintentional cessation of agricultural activities for takeover by other land uses, is becoming increasingly common. Although widely studied, the outcomes of cultivated land abandonment are highly context-dependent and varied. Understanding this phenomenon would thus benefit from placed-based social-ecological case study perspectives, particularly in more understudied contexts. This study represents such a perspective, taking a social-ecological approach to understand how land abandonment has emerged and what its consequences are for the desired future outcomes in the Hlankomo and Lower Tsitsana villages in the Tsitsa River catchment. Drawing on McGinnis & Ostrom’s (2009) framework, I framed cultivated land abandonment in my study area as a “focal action situation” informed by the interaction of natural resource systems, governance systems, actors, and resource units. To better understand the current state of the natural resource system and important ecological (resource) units (grass), I used two measures of ecological condition: a rapid assessment test that provided a broad, if superficial, understanding of degradation and land condition, and a veld condition assessment that provided an understanding of grassland composition and quality in abandoned fields. I also used aerial photographs to assess the extent of changes in abandoned cultivation in the catchment. To understand actors, governance systems, how they interacted with natural resource systems and units for land abandonment to emerge, and what implications these interactions may have for the future of these lands, I used semi-structured interviews. The Rapid Assessment Test tool showed that the abandoned cultivated fields were dominated by grasses (58.3%), while shrubs (11%) and succulents (11%) were the least prevalent. The veld assessment identified sixteen grass species in both villages, with Aristida junciformis (23%) and Eragrostis plana (22.2 %) being the most dominant. The grazing statuses of the grasses showed that there were more Increaser II species, followed by Increaser III, Exotic, Increaser I and Decreaser species, respectively. There were more grass species with low grazing and average grazing values than grass species with high grazing values. The Rapid Assessment tool and the Veld assessment showed that the fields were dominated by poor grass species that grow on degraded lands. The results thus showed that the abandoned cultivated lands are degraded and in poor condition, as they are covered mainly by poor grass species that are dominant in over-utilised and overgrazed areas. The aerial photographs showed a decline in cultivated lands from 1966 to 2015, with a significant decline between 1966 and 2003. The land under cultivation between 1966 and 2003 decreased by 95 %, resulting in an annual decline of 2.56 %. The land under cultivation from 2003 and 2015 decreased by 60 %, resulting in a decline of 4 % per year. Local people corroborated the increase in cultivated land abandonment in the interviews, and this is why I attempt to understand why abandoned cultivated land happened (how the resource system and governance systems/actors interacted to shape cultivated land abandonment). As in other South African rural contexts, reasons people gave for land cultivation abandonment revealed the strongly intertwined nature of ecological and social systems, including no fence, livestock eating crops, no cattle, lack of labour, migration, lack of resources (money and equipment), parents passing on, expensive fertilizers, rainfall variability, dependency on grants, lack of interest and laziness. People had different views about the future of the abandoned cultivated lands, suggesting building homes, recreational parks, poultry farms, and recultivating and livestock protection camps, while others indicated that they didn’t care what happens to the abandoned fields. Many people still value abandoned lands and would prefer for the land to be recultivated, but they are held back by factors beyond their control, such as no fencing and a lack of governmental support in the form of fertilisers and machinery for ploughing. Additionally, our ecological results suggest that, due to the degraded states of these lands, significant rehabilitation would be required to realize these desired outcomes. Overall, this study shows the social-ecological complexity that drives cultivated land abandonment in the Tsitsa River catchment, providing a context-specific understanding of the drivers and consequences of abandoned cultivated land, future options more specific to these villages, and the broader Tsitsa catchment. At the same time, my study also corroborates similar studies in rural African and other global South contexts, thus supporting generalizable knowledge that can be used in the development of agrarian, social and environmental policies in these regions. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2024
- Full Text:
- Date Issued: 2024-10-11
The development of dual-action antimalarial compounds
- Authors: Vinindwa, Bonani
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466625 , vital:76761
- Description: Access restricted. Expected release in 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Vinindwa, Bonani
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466625 , vital:76761
- Description: Access restricted. Expected release in 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
The development of mobile money services and financial inclusion in Zimbabwe
- Authors: Chingono, Kudzaishe Emily
- Date: 2024-10-11
- Subjects: Mobile commerce Zimbabwe , Financial inclusion , Automated tellers , Financial literacy , Education Social aspects South Africa , Technology and older people South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/462691 , vital:76326
- Description: Purpose- The use of mobile phones in Zimbabwe fostered the development of various financial innovations, such as mobile money services. It is important to note that the use of mobile money services in Zimbabwe has gradually increased. This study was carried out to determine the relationship between the development of mobile money services and financial inclusion in Zimbabwe. The main goal was to determine if there is a correlation between financial inclusion and the development of mobile money services. Design and Methodological approach: This study used a quantitative research design in which time series data was used to generate the analysis. The data used in the study covered a period of 20 years, starting from 2000 to 2020 on a yearly basis. Auto Regressive Distributed Lag (ARDL) Model was used to analyze the relationship. Findings: The ARDL study results showed that in the long run, there is no statistically significant correlation between the development of mobile money services and financial inclusion, and this is suggested by the long-term relationship between the two variables over a period of 20 years. In the short run, the study findings showed that the development of mobile money services have a positive significant influence on financial inclusion with. Therefore, increase in mobile money usage was associated with increase in financial inclusion. Between the period 2000 and 2020, the major determinants of mobile moneys services are age, number of ATMs, financial literacy, income level and mobile phone penetration. The tests also showed that these variables significantly and positively influenced use of mobile money as a financial inclusion tool in Zimbabwe (p<.05). Research Limitations: The study did not find a lot of current relevant literature that would explain the relationship between mobile money services and financial inclusion. Majority of the work was carried out in other countries, and little was covered in Zimbabwe. Practical Implications: The study results implies that government should put in place measure to ensure the expansion of mobile money services in the rural areas. The mobile telecommunication firms should ensure increased mobile phone penetration. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Chingono, Kudzaishe Emily
- Date: 2024-10-11
- Subjects: Mobile commerce Zimbabwe , Financial inclusion , Automated tellers , Financial literacy , Education Social aspects South Africa , Technology and older people South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/462691 , vital:76326
- Description: Purpose- The use of mobile phones in Zimbabwe fostered the development of various financial innovations, such as mobile money services. It is important to note that the use of mobile money services in Zimbabwe has gradually increased. This study was carried out to determine the relationship between the development of mobile money services and financial inclusion in Zimbabwe. The main goal was to determine if there is a correlation between financial inclusion and the development of mobile money services. Design and Methodological approach: This study used a quantitative research design in which time series data was used to generate the analysis. The data used in the study covered a period of 20 years, starting from 2000 to 2020 on a yearly basis. Auto Regressive Distributed Lag (ARDL) Model was used to analyze the relationship. Findings: The ARDL study results showed that in the long run, there is no statistically significant correlation between the development of mobile money services and financial inclusion, and this is suggested by the long-term relationship between the two variables over a period of 20 years. In the short run, the study findings showed that the development of mobile money services have a positive significant influence on financial inclusion with. Therefore, increase in mobile money usage was associated with increase in financial inclusion. Between the period 2000 and 2020, the major determinants of mobile moneys services are age, number of ATMs, financial literacy, income level and mobile phone penetration. The tests also showed that these variables significantly and positively influenced use of mobile money as a financial inclusion tool in Zimbabwe (p<.05). Research Limitations: The study did not find a lot of current relevant literature that would explain the relationship between mobile money services and financial inclusion. Majority of the work was carried out in other countries, and little was covered in Zimbabwe. Practical Implications: The study results implies that government should put in place measure to ensure the expansion of mobile money services in the rural areas. The mobile telecommunication firms should ensure increased mobile phone penetration. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2024
- Full Text:
- Date Issued: 2024-10-11
The dynamics of novice and experienced Namibian teachers’ adoption of the Advanced Subsidiary Agricultural Science curriculum
- Authors: Nanyemba, Wilhelmina
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/463581 , vital:76422
- Description: Access restricted. Expected release date 2026. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Nanyemba, Wilhelmina
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/463581 , vital:76422
- Description: Access restricted. Expected release date 2026. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-10-11
The effect of an alkyl chain and β-diketonato-metal moiety on the photochromic behaviour of azobenzene compounds as materials for solar thermal fuels
- Authors: Bokhe, Witness Londi
- Date: 2024-10-11
- Subjects: Photochemistry , Isomerization , Solar thermal energy , Solar thermal fuel , Liquid crystals , Optical materials
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464510 , vital:76517
- Description: Scientists have been studying the development of renewable energy technologies in detail to create a sustainable energy supply. Among many new advanced material classes being researched recently are photo functional and photo responsive materials. These classes include azobenzene derivatives which are characterized by azo linkage (N=N) sandwiched by two phenyl rings. The trans-to-cis isomerization of azobenzene is a highly efficient and reversible process, making it an ideal candidate for solar thermal energy storage. This research investigates the impact of alkyl chain modifications and the incorporation of a β-diketonato-copper(II) complex on azobenzene derivatives, aiming to optimize their performance as efficient components in solar thermal fuel cells (STFs). The study focuses on a comprehensive analysis of these materials' ability to capture, convert, store, and release solar energy for enhanced sustainability in renewable energy applications. Experimental methodologies include synthesis of azobenzene derivatives with varying alkyl chain length, n (where n =8 & 10) and coordination of these compounds with a β-diketonato-copper(II) complex. Standard analytical techniques such as Nuclear Magnetic Resonance (1H and 13C NMR), Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet/visible spectroscopy (UV/vis) were employed for chemical analysis of the synthesized material. Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and Polarised Optical Microscope (POM) were used to study the thermal properties and morphology. The photostationery states were determined using NMR spectroscopy and the kinetic parameters of the cis-to-trans relaxation process determined by a UV spectroscopy study. The cis-to-trans isomerisation had a longer half-life than the trans-to-cis isomerisation. The band gap of the isomers is within the range of semiconducting inorganic materials. DSC and POM thermograms showed that the compounds are liquid crystalline. Finally, the study reports that the synthesised azobenzene derivatives show potential as material for solar thermal fuel cells because of their photo-isomerization ability. Furthermore, the synthesised compounds contribute to the advancement of sustainable and efficient solar energy utilization technologies, addressing the growing demand for clean energy solutions in the face of global environmental challenges. Because solar energy may be stored and used without causing direct emissions or pollution, they are considered clean energy. If solar thermal fuels fulfil sustainability standards, they may qualify as green energy. This entails minimising adverse effects on the environment, using non-toxic chemicals and procedures. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Bokhe, Witness Londi
- Date: 2024-10-11
- Subjects: Photochemistry , Isomerization , Solar thermal energy , Solar thermal fuel , Liquid crystals , Optical materials
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464510 , vital:76517
- Description: Scientists have been studying the development of renewable energy technologies in detail to create a sustainable energy supply. Among many new advanced material classes being researched recently are photo functional and photo responsive materials. These classes include azobenzene derivatives which are characterized by azo linkage (N=N) sandwiched by two phenyl rings. The trans-to-cis isomerization of azobenzene is a highly efficient and reversible process, making it an ideal candidate for solar thermal energy storage. This research investigates the impact of alkyl chain modifications and the incorporation of a β-diketonato-copper(II) complex on azobenzene derivatives, aiming to optimize their performance as efficient components in solar thermal fuel cells (STFs). The study focuses on a comprehensive analysis of these materials' ability to capture, convert, store, and release solar energy for enhanced sustainability in renewable energy applications. Experimental methodologies include synthesis of azobenzene derivatives with varying alkyl chain length, n (where n =8 & 10) and coordination of these compounds with a β-diketonato-copper(II) complex. Standard analytical techniques such as Nuclear Magnetic Resonance (1H and 13C NMR), Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet/visible spectroscopy (UV/vis) were employed for chemical analysis of the synthesized material. Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and Polarised Optical Microscope (POM) were used to study the thermal properties and morphology. The photostationery states were determined using NMR spectroscopy and the kinetic parameters of the cis-to-trans relaxation process determined by a UV spectroscopy study. The cis-to-trans isomerisation had a longer half-life than the trans-to-cis isomerisation. The band gap of the isomers is within the range of semiconducting inorganic materials. DSC and POM thermograms showed that the compounds are liquid crystalline. Finally, the study reports that the synthesised azobenzene derivatives show potential as material for solar thermal fuel cells because of their photo-isomerization ability. Furthermore, the synthesised compounds contribute to the advancement of sustainable and efficient solar energy utilization technologies, addressing the growing demand for clean energy solutions in the face of global environmental challenges. Because solar energy may be stored and used without causing direct emissions or pollution, they are considered clean energy. If solar thermal fuels fulfil sustainability standards, they may qualify as green energy. This entails minimising adverse effects on the environment, using non-toxic chemicals and procedures. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
The effect of biological control on the population dynamics of Pontederia crassipes Mart. (Pontederiaceae) and Salvinia minima Baker (Salviniales: Salviniaceae)
- Authors: Chikodza, Tressia
- Date: 2024-10-11
- Subjects: Pontederia crassipes , Salvinia minima , Pontederiaceae Biological control South Africa , Salviniaceae Biological control South Africa , Population dynamics , Secondary invasion
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464462 , vital:76513
- Description: Pontederia crassipes is widely regarded as the most damaging floating aquatic weed in terms of its invasive traits, and its impact on aquatic ecosystems. Biological control using host-specific natural enemies is widely used for its control, with the most recent agent released being a planthopper, Megamelus scutellaris, in South Africa and the USA. In South Africa, inundative releases of M. scutellaris have been shown to control the weed even at eutrophic, and high elevation cold sites, such as Hartbeespoort Dam, arguably Africa’s most hypertrophic impoundment. However, subsequent to the control of P. crassipes on Hartbeespoort Dam, in 2021, a secondary invader, Salvinia minima, dominated the water system. Salvinia minima is only known from a handful sites near Hartbeespoort Dam and there is currently no approved biocontrol agent for it. The population dynamics of P. crassipes and S. minima at the Dam were overall interchanging due to insect feeding on M. scutellaris reducing P. crassipes populations thus allowing S. minima to become dominant. Intense feeding from M. scutellaris resulted in the reduction of P. crassipes populations. During late autumn and winter, remaining P. crassipes plants experienced frost damage from cold temperatures. The decrease in P. crassipes allowed S. minima to successfully invade, potentially as the result of less competition from P. crassipes, and therefore available resources, such as space, nutrients, and light. However, as spring approached, P. crassipes regenerated from its seed bank, and S. minima populations diminished. The changes in dominance were observed in 2021 and 2022 but in 2023, this trend was not evident as S. minima did not dominate as in previous years. This thesis investigated the combination of competition and herbivory by M. scutellaris on the vigour of P. crassipes and S. minima to understand the dynamics of these two highly invasive species. Competitive abilities of P. crassipes and S. minima were determined using an inverse linear model with plant weight as the yield variable. In the absence of herbivory, P. crassipes, was 4 times more competitive than S. minima, but as competitive when exposed to M. scutellaris feeding. Salvinia minima was 1.2 times as aggressive as P. crassipes in the absence of herbivory, but 2.6 times as competitive when M. scutellaris was established on P. crassipes. In the presence of herbivory on P. crassipes, interspecific competition coefficients from P. crassipes on S. minima were no longer statistically significant. These results indicate that the competitive ability of P. crassipes was reduced through herbivory when grown with S. minima, explaining the temporal dominance between the two species at Hartbeespoort Dam. Some studies have reported that P. crassipes releases allelochemicals as a competitive strategy to algae and phytoplankton. Previously identified allelochemicals include N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine and linoleic acid. This thesis investigated the presence or absence of key chemical compounds released by P. crassipes during allelopathy with microbes and phytoplankton to determine its potential to inhibit S. minima growth. Methanol extracts from P. crassipes roots, leaves, and field samples underwent LC-ESI-MS/MS analysis, creating a molecular network to match chemical profiles. Of the investigated compounds, N-phenyl-1-naphthylamine and N-phenyl-2-naphthylamine were absent in P. crassipes and field samples, while linoleic acid was consistently found. Its presence suggests its potential defensive role against S. minima. Future research should explore allelochemical production in the presence of S. minima and algae to confirm if S. minima elicits an allelochemical response by P. crassipes, or whether the methods used here were insufficient to detect allelochemical production. Understanding whether P. crassipes employs allelochemicals, especially in the presence of S. minima, could shed light on its competitive advantage beyond its invasive nature at the Dam. , Thesis (MSc) -- Faculty of Science, Botany, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Chikodza, Tressia
- Date: 2024-10-11
- Subjects: Pontederia crassipes , Salvinia minima , Pontederiaceae Biological control South Africa , Salviniaceae Biological control South Africa , Population dynamics , Secondary invasion
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464462 , vital:76513
- Description: Pontederia crassipes is widely regarded as the most damaging floating aquatic weed in terms of its invasive traits, and its impact on aquatic ecosystems. Biological control using host-specific natural enemies is widely used for its control, with the most recent agent released being a planthopper, Megamelus scutellaris, in South Africa and the USA. In South Africa, inundative releases of M. scutellaris have been shown to control the weed even at eutrophic, and high elevation cold sites, such as Hartbeespoort Dam, arguably Africa’s most hypertrophic impoundment. However, subsequent to the control of P. crassipes on Hartbeespoort Dam, in 2021, a secondary invader, Salvinia minima, dominated the water system. Salvinia minima is only known from a handful sites near Hartbeespoort Dam and there is currently no approved biocontrol agent for it. The population dynamics of P. crassipes and S. minima at the Dam were overall interchanging due to insect feeding on M. scutellaris reducing P. crassipes populations thus allowing S. minima to become dominant. Intense feeding from M. scutellaris resulted in the reduction of P. crassipes populations. During late autumn and winter, remaining P. crassipes plants experienced frost damage from cold temperatures. The decrease in P. crassipes allowed S. minima to successfully invade, potentially as the result of less competition from P. crassipes, and therefore available resources, such as space, nutrients, and light. However, as spring approached, P. crassipes regenerated from its seed bank, and S. minima populations diminished. The changes in dominance were observed in 2021 and 2022 but in 2023, this trend was not evident as S. minima did not dominate as in previous years. This thesis investigated the combination of competition and herbivory by M. scutellaris on the vigour of P. crassipes and S. minima to understand the dynamics of these two highly invasive species. Competitive abilities of P. crassipes and S. minima were determined using an inverse linear model with plant weight as the yield variable. In the absence of herbivory, P. crassipes, was 4 times more competitive than S. minima, but as competitive when exposed to M. scutellaris feeding. Salvinia minima was 1.2 times as aggressive as P. crassipes in the absence of herbivory, but 2.6 times as competitive when M. scutellaris was established on P. crassipes. In the presence of herbivory on P. crassipes, interspecific competition coefficients from P. crassipes on S. minima were no longer statistically significant. These results indicate that the competitive ability of P. crassipes was reduced through herbivory when grown with S. minima, explaining the temporal dominance between the two species at Hartbeespoort Dam. Some studies have reported that P. crassipes releases allelochemicals as a competitive strategy to algae and phytoplankton. Previously identified allelochemicals include N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine and linoleic acid. This thesis investigated the presence or absence of key chemical compounds released by P. crassipes during allelopathy with microbes and phytoplankton to determine its potential to inhibit S. minima growth. Methanol extracts from P. crassipes roots, leaves, and field samples underwent LC-ESI-MS/MS analysis, creating a molecular network to match chemical profiles. Of the investigated compounds, N-phenyl-1-naphthylamine and N-phenyl-2-naphthylamine were absent in P. crassipes and field samples, while linoleic acid was consistently found. Its presence suggests its potential defensive role against S. minima. Future research should explore allelochemical production in the presence of S. minima and algae to confirm if S. minima elicits an allelochemical response by P. crassipes, or whether the methods used here were insufficient to detect allelochemical production. Understanding whether P. crassipes employs allelochemicals, especially in the presence of S. minima, could shed light on its competitive advantage beyond its invasive nature at the Dam. , Thesis (MSc) -- Faculty of Science, Botany, 2024
- Full Text:
- Date Issued: 2024-10-11
The effects of Human-Wildlife Conflict (HWC) on mental health: the case of Shezongo Community of Kafue National Park (KNP), Zambia
- Authors: Smith, Loryn Janine
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/465843 , vital:76658
- Description: Background: Human-wildlife conflict (HWC) is a bi-directional relationship affecting man and wild animals. Both species suffer extreme consequences, including encroachment of man into wildlife habitats and the destruction of crops and livestock by wildlife foraging for food sources. HWC is particularly prominent in Game Management Areas (GMAs), situated as buffer zones around national parks. Subsequent conflict between man and wildlife leads to not only physical harm but also psychological distress, exacerbating the consequences for mental health. Objectives: A mixed methods design was used to investigate the effects of HWC on mental health. The study aimed to determine the hidden nature of HWC within a population residing in a GMA region in Kafue National Park, Zambia. Methods: Forty-two participants took part in this study, representing a diverse range of demographic characteristics. Of these, 40 participants completed quantitative measures investigating the effect of HWC on mental health. Additionally, eight participants participated in interviews on the nature of mental health in the context of HWC. Some interview participants also completed the quantitative measures, while others did not. Thematic analysis guided qualitative investigations, while Chi-Square Analyses and Fisher’s Exact Test were used to investigate the association between HWC and mental health. Results and Conclusions: The study found an association between HWC and heightened psychological distress in rural communities residing in GMA areas. Further research is required to improve the symbiotic relationship between man and wildlife, considering the consequences of HWC on human well-being and mental health. , Thesis (MA) -- Faculty of Humanities, Psychology, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Smith, Loryn Janine
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/465843 , vital:76658
- Description: Background: Human-wildlife conflict (HWC) is a bi-directional relationship affecting man and wild animals. Both species suffer extreme consequences, including encroachment of man into wildlife habitats and the destruction of crops and livestock by wildlife foraging for food sources. HWC is particularly prominent in Game Management Areas (GMAs), situated as buffer zones around national parks. Subsequent conflict between man and wildlife leads to not only physical harm but also psychological distress, exacerbating the consequences for mental health. Objectives: A mixed methods design was used to investigate the effects of HWC on mental health. The study aimed to determine the hidden nature of HWC within a population residing in a GMA region in Kafue National Park, Zambia. Methods: Forty-two participants took part in this study, representing a diverse range of demographic characteristics. Of these, 40 participants completed quantitative measures investigating the effect of HWC on mental health. Additionally, eight participants participated in interviews on the nature of mental health in the context of HWC. Some interview participants also completed the quantitative measures, while others did not. Thematic analysis guided qualitative investigations, while Chi-Square Analyses and Fisher’s Exact Test were used to investigate the association between HWC and mental health. Results and Conclusions: The study found an association between HWC and heightened psychological distress in rural communities residing in GMA areas. Further research is required to improve the symbiotic relationship between man and wildlife, considering the consequences of HWC on human well-being and mental health. , Thesis (MA) -- Faculty of Humanities, Psychology, 2024
- Full Text:
- Date Issued: 2024-10-11