Assessing rural senior primary school natural science teachers’ TPACK: a case study
- Authors: Silvanus, Secilia Tulikefo
- Date: 2024-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423902 , vital:72103
- Description: In today's world, technology has changed how people live and behave. The influence of technology contemplates a similar change in the education processes of teaching and learning. Many governments worldwide invest hugely in providing technological tools and facilities and training teachers to improve teaching and learning. The availability and access to technologies in schools seem to offer teachers opportunities to develop technological knowledge and integrate technology into teaching. Literature indicates that teachers must possess technological pedagogical content knowledge (TPACK) to integrate technology into teaching and learning processes effectively. However, other scholars have also suggested that teachers' TPACK develops and is shaped by many contexts. This study, therefore, sought to assess the rural senior primary Natural science teachers' TPACK. This qualitative case study was conducted with senior primary Natural science teachers in the educational circuit of Endola. An interpretive paradigm underpinned the study. The study employed semi-structured questionnaires, semi-structured interviews, focus group interviews, and observation to collect the data. The study used the TPACK as a theoretical and analytical framework. The study results showed that participants had a firmer grasp of subject content (CK) and traditional teaching methods (Pedagogical Knowledge - PK and Pedagogical Content Knowledge - PCK) compared to technological knowledge (TK) and technology-based pedagogies (Technological Pedagogical Knowledge - TPK, Technological Content Knowledge - TCK, and Technological Pedagogical Content Knowledge (TPCK). Findings support that the participants draw upon sources of Technological Pedagogical Content Knowledge (TPACK) closely aligned with Content Knowledge (CK), Technological Content Knowledge (TCK), and Technological Pedagogical Knowledge (TPK) to integrate technology. The study included inadequate professional development, teachers' attitudes, insufficient hardware and internet connectivity, limited technological knowledge, time constraints, and restricted access to technology tools and resources as obstacles for teachers attempting to incorporate technology into their classrooms effectively. Furthermore, the data highlights ICT training and teachers' interest as enablers that motivated participants to integrate technology into their teaching practices. Therefore, the study recommends professional development programs focusing on providing science teachers with practical skills to utilise different technologies and address common technical issues. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Silvanus, Secilia Tulikefo
- Date: 2024-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423902 , vital:72103
- Description: In today's world, technology has changed how people live and behave. The influence of technology contemplates a similar change in the education processes of teaching and learning. Many governments worldwide invest hugely in providing technological tools and facilities and training teachers to improve teaching and learning. The availability and access to technologies in schools seem to offer teachers opportunities to develop technological knowledge and integrate technology into teaching. Literature indicates that teachers must possess technological pedagogical content knowledge (TPACK) to integrate technology into teaching and learning processes effectively. However, other scholars have also suggested that teachers' TPACK develops and is shaped by many contexts. This study, therefore, sought to assess the rural senior primary Natural science teachers' TPACK. This qualitative case study was conducted with senior primary Natural science teachers in the educational circuit of Endola. An interpretive paradigm underpinned the study. The study employed semi-structured questionnaires, semi-structured interviews, focus group interviews, and observation to collect the data. The study used the TPACK as a theoretical and analytical framework. The study results showed that participants had a firmer grasp of subject content (CK) and traditional teaching methods (Pedagogical Knowledge - PK and Pedagogical Content Knowledge - PCK) compared to technological knowledge (TK) and technology-based pedagogies (Technological Pedagogical Knowledge - TPK, Technological Content Knowledge - TCK, and Technological Pedagogical Content Knowledge (TPCK). Findings support that the participants draw upon sources of Technological Pedagogical Content Knowledge (TPACK) closely aligned with Content Knowledge (CK), Technological Content Knowledge (TCK), and Technological Pedagogical Knowledge (TPK) to integrate technology. The study included inadequate professional development, teachers' attitudes, insufficient hardware and internet connectivity, limited technological knowledge, time constraints, and restricted access to technology tools and resources as obstacles for teachers attempting to incorporate technology into their classrooms effectively. Furthermore, the data highlights ICT training and teachers' interest as enablers that motivated participants to integrate technology into their teaching practices. Therefore, the study recommends professional development programs focusing on providing science teachers with practical skills to utilise different technologies and address common technical issues. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-04
Exploring senior phase teachers’ use of kahoot! Gamification as a formative assessment tool to scaffold mathematical understanding
- Authors: Balele, Silence
- Date: 2024-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423891 , vital:72102
- Description: In South Africa, digital technology, particularly gamification, continues to become an important teaching and learning tool. Its importance lies in scaffolding mathematical understanding, improving the quality of assessment, and developing twenty-first-century technological skills for effective mathematics assessment. To explore this importance, senior phase mathematics teachers are encouraged to adopt gamification technology such as Kahoot! in assessment. The study adopted a case study research design with a interpretivist research paradigm, as this method allows detailed exploration and understanding of a specific context through a close connection with the participants. Data was collected using semi-structured questionnaires, focus group interviews, non-participant observations, and reflective journals. The research involved ten purposively selected senior-phase mathematics teachers from two schools in the Sarah Baartman District, Eastern Cape Province, South Africa. The study drew upon Vygoysky's Sociocultural Theory for its theoretical framework, while the Technological, Pedagogical, and Content Knowledge was used for analysis. The data analysis pursued an inductive approach. Adopting a thematic analysis included coding participant responses, organizing codes into concepts and categories, and developing a theoretical framework from the resultant categories. A four-phase process was involved: coding, conceptualizing, categorizing, and theorizing, was employed. This process and using NVivo software for data organization and management helped identify patterns, themes, and significant concerns surrounding the study's core subject. The findings from the study were as follows: Firstly, it was revealed that most teachers have a positive perception and attitude towards using Kahoot! for formative assessment, believing that it enhances teaching and learning quality. However, they showed scepticism due to insufficient Information and Communication Technologies knowledge and training. Second, teachers' pedagogical and technological experiences were predominantly enjoyable. Kahoot! was accepted as beneficial for promoting collaboration, interaction, and immediate feedback. Third, the study identified enabling and constraining factors in using Kahoot! for formative assessment. The enabling factors include Kahoot!, which was convenient and accessible, promoted immediate feedback and fostered collaboration and interaction. The constraining factors include Information and Communication Technologies and network interference, which posed limitations. The research concluded that Kahoot! as a platform for formative assessment indeed scaffold mathematical understanding. The study recommends increasing teachers' access to educational technology, incorporating continuous professional development programs, providing subject-specific training, and encouraging teachers to adapt to emerging technologies. The study also provided recommendations for future research to explore learner perceptions, employ a mixed methods approach to help quantify learner performance and investigate the pedagogical and technological experiences of senior phase mathematics teachers regarding formative assessment. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Balele, Silence
- Date: 2024-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423891 , vital:72102
- Description: In South Africa, digital technology, particularly gamification, continues to become an important teaching and learning tool. Its importance lies in scaffolding mathematical understanding, improving the quality of assessment, and developing twenty-first-century technological skills for effective mathematics assessment. To explore this importance, senior phase mathematics teachers are encouraged to adopt gamification technology such as Kahoot! in assessment. The study adopted a case study research design with a interpretivist research paradigm, as this method allows detailed exploration and understanding of a specific context through a close connection with the participants. Data was collected using semi-structured questionnaires, focus group interviews, non-participant observations, and reflective journals. The research involved ten purposively selected senior-phase mathematics teachers from two schools in the Sarah Baartman District, Eastern Cape Province, South Africa. The study drew upon Vygoysky's Sociocultural Theory for its theoretical framework, while the Technological, Pedagogical, and Content Knowledge was used for analysis. The data analysis pursued an inductive approach. Adopting a thematic analysis included coding participant responses, organizing codes into concepts and categories, and developing a theoretical framework from the resultant categories. A four-phase process was involved: coding, conceptualizing, categorizing, and theorizing, was employed. This process and using NVivo software for data organization and management helped identify patterns, themes, and significant concerns surrounding the study's core subject. The findings from the study were as follows: Firstly, it was revealed that most teachers have a positive perception and attitude towards using Kahoot! for formative assessment, believing that it enhances teaching and learning quality. However, they showed scepticism due to insufficient Information and Communication Technologies knowledge and training. Second, teachers' pedagogical and technological experiences were predominantly enjoyable. Kahoot! was accepted as beneficial for promoting collaboration, interaction, and immediate feedback. Third, the study identified enabling and constraining factors in using Kahoot! for formative assessment. The enabling factors include Kahoot!, which was convenient and accessible, promoted immediate feedback and fostered collaboration and interaction. The constraining factors include Information and Communication Technologies and network interference, which posed limitations. The research concluded that Kahoot! as a platform for formative assessment indeed scaffold mathematical understanding. The study recommends increasing teachers' access to educational technology, incorporating continuous professional development programs, providing subject-specific training, and encouraging teachers to adapt to emerging technologies. The study also provided recommendations for future research to explore learner perceptions, employ a mixed methods approach to help quantify learner performance and investigate the pedagogical and technological experiences of senior phase mathematics teachers regarding formative assessment. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-04
Relationship Management in All-Boys’ Fee-paying Public Schools in the Eastern Cape, South Africa : Experiences and Perspectives of LGBTQ Alumni
- Authors: Mahlangu, Nhlakanipho
- Date: 2024-04
- Subjects: Gay men , Teenage boys , Public schools -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62237 , vital:72364
- Description: This study explores the perspectives and experiences of LGBTQ alumni of all-boys’ schools in the Eastern Cape. The context of increased competition between schools in the education sector and the importance of inclusion within the sector necessitated a study to investigate the extent to which relationship management is conducted with an orientation towards LGBTQ inclusion in all-boys’ schools in the Eastern Cape. Student protests in South Africa over the past 10 years have expanded concerns about student belonging beyond the widely studied lenses of race and class. A growing body of literature and wider discourse emphasises student belonging as a challenge in the South African education sector. Marginalised students continue to experience educational spaces negatively. LGBTQ student experiences in the South Africa are characterised by violence and ostracisation, thus warranting further investigation and inquiry. The study locates itself in the intersections between gender and sexual diversity and economic citizenship in the broader discourse of school inclusivity. A qualitative research approach was employed, making use of semi-structured, in-depth individual interviews. The sample was derived from alumni of all-boys’ schools in the Eastern Cape through snowball sampling. Ten LGBTQ-identifying alumni of boys’ schools in the Eastern Cape were interviewed. The findings reveal the need to question the extent to which LGBTQ alumni can enjoy the fullness of the value proposition of all-boys’ schools, and what can be done to ensure LGBTQ belonging. The findings of this study concur with existing literature about LGBTQ experiences. Participants defined their school experiences as exclusionary and characterised by fear of failing to assert themselves in a hypermasculine school environment. LGBTQ alumni of all-boys’ schools in the Eastern Cape view relationship management as under-utilised as a tool to facilitate LGBTQ belonging. Instead, relationship management is used to affirm those who fit the mould of the quintessential ‘old boy’ network, by defining the masculine behaviours that learners in all-boys’ schools are compelled to aspire towards. v ABSTRACT The findings illustrate that the culture of silence around non-confirming sexuality is sustained in the post-schooling relationship management life-cycle and results in the absence of the LGBTQ customer voice in the drafting of school strategy and policy. LGBTQ alumni who speak out about controversial issues often face admonition from their former teachers and peers. LGBTQ alumni criticise the relationship management of their former schools for the over-emphasis on fundraising and the complete absence of discussions on diversity. LGBTQ alumni are therefore marginalised in the process of value co-creation, as LGBTQ alumni feel they will never be viewed as legitimate collaborators by their former schools. The suggested recommendations emerging from this study include the need to codify school policies that speak specifically to LGBTQ marginalisation. Furthermore, schools must endeavour to make specific enquiries into LGBTQ student experiences and include LGBTQ concerns in wider school discourse. , Thesis (Ma) -- Faculty of Business and Economic Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Mahlangu, Nhlakanipho
- Date: 2024-04
- Subjects: Gay men , Teenage boys , Public schools -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62237 , vital:72364
- Description: This study explores the perspectives and experiences of LGBTQ alumni of all-boys’ schools in the Eastern Cape. The context of increased competition between schools in the education sector and the importance of inclusion within the sector necessitated a study to investigate the extent to which relationship management is conducted with an orientation towards LGBTQ inclusion in all-boys’ schools in the Eastern Cape. Student protests in South Africa over the past 10 years have expanded concerns about student belonging beyond the widely studied lenses of race and class. A growing body of literature and wider discourse emphasises student belonging as a challenge in the South African education sector. Marginalised students continue to experience educational spaces negatively. LGBTQ student experiences in the South Africa are characterised by violence and ostracisation, thus warranting further investigation and inquiry. The study locates itself in the intersections between gender and sexual diversity and economic citizenship in the broader discourse of school inclusivity. A qualitative research approach was employed, making use of semi-structured, in-depth individual interviews. The sample was derived from alumni of all-boys’ schools in the Eastern Cape through snowball sampling. Ten LGBTQ-identifying alumni of boys’ schools in the Eastern Cape were interviewed. The findings reveal the need to question the extent to which LGBTQ alumni can enjoy the fullness of the value proposition of all-boys’ schools, and what can be done to ensure LGBTQ belonging. The findings of this study concur with existing literature about LGBTQ experiences. Participants defined their school experiences as exclusionary and characterised by fear of failing to assert themselves in a hypermasculine school environment. LGBTQ alumni of all-boys’ schools in the Eastern Cape view relationship management as under-utilised as a tool to facilitate LGBTQ belonging. Instead, relationship management is used to affirm those who fit the mould of the quintessential ‘old boy’ network, by defining the masculine behaviours that learners in all-boys’ schools are compelled to aspire towards. v ABSTRACT The findings illustrate that the culture of silence around non-confirming sexuality is sustained in the post-schooling relationship management life-cycle and results in the absence of the LGBTQ customer voice in the drafting of school strategy and policy. LGBTQ alumni who speak out about controversial issues often face admonition from their former teachers and peers. LGBTQ alumni criticise the relationship management of their former schools for the over-emphasis on fundraising and the complete absence of discussions on diversity. LGBTQ alumni are therefore marginalised in the process of value co-creation, as LGBTQ alumni feel they will never be viewed as legitimate collaborators by their former schools. The suggested recommendations emerging from this study include the need to codify school policies that speak specifically to LGBTQ marginalisation. Furthermore, schools must endeavour to make specific enquiries into LGBTQ student experiences and include LGBTQ concerns in wider school discourse. , Thesis (Ma) -- Faculty of Business and Economic Sciences, 2024
- Full Text:
- Date Issued: 2024-04
Technological Pedagogical Content Knowledge (TPACK): investigating senior primary mathematics teachers’ integration of technology in the classroom in Okahao educational circuit
- Shikesho, Hilya Ndahambelela
- Authors: Shikesho, Hilya Ndahambelela
- Date: 2024-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423913 , vital:72104
- Description: The overwhelming advancement of ICT devices in the contemporary Namibian education system has led to their praise for supporting differentiated instruction, fostering collaboration, and engaging multiple intelligences in teaching and learning. Consequently, the compulsory incorporation of ICTs into the teaching and learning process becomes imperative across various fields of study, including Mathematics. However, the integration of technology-based teaching proves to be a complex and challenging issue, often considered a wicked problem. To explore this matter, a qualitative case study was conducted to investigate how Senior Primary Mathematics Teachers integrated technology to develop their TPACK. The study was conducted among the twenty-seven senior primary mathematics teachers in the Okahao educational circuit in the Omuasti region. The study utilized Vygotsky‘s (1978); Socio-cultural Theory, together with Mishra and Koehler (2006), and; the Technological Pedagogical Content Knowledge (TPACK) framework was used as a lens to analyse the data. The data were gathered through semi-structured questionnaires, semi-structured interviews, focus group interviews, and lesson observations. The study findings indicate that senior primary mathematics teachers utilize the available resources at their respective schools during their classroom instruction. The study further reveals that mathematics teachers exhibit a positive attitude toward the integration of technology. The study uncovers the intricate interplay between technological knowledge, pedagogical expertise, and content knowledge within the context of mathematics education. The findings reveal that while participants demonstrate a high level of proficiency in certain TPACK components such as CK, TK, PK, TPK, and PCK, they expressed a moderate level of expertise in TCK and TPCK. The study also identified challenges in TPACK development, particularly the need for subject specific technology training, lack of technological infrastructure, particularly advanced technology, as well as a deficiency in ICT knowledge. The importance of access to various technologies was emphasized, enabling teachers to seamlessly integrate technology into their practices and address diverse learning styles. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Shikesho, Hilya Ndahambelela
- Date: 2024-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423913 , vital:72104
- Description: The overwhelming advancement of ICT devices in the contemporary Namibian education system has led to their praise for supporting differentiated instruction, fostering collaboration, and engaging multiple intelligences in teaching and learning. Consequently, the compulsory incorporation of ICTs into the teaching and learning process becomes imperative across various fields of study, including Mathematics. However, the integration of technology-based teaching proves to be a complex and challenging issue, often considered a wicked problem. To explore this matter, a qualitative case study was conducted to investigate how Senior Primary Mathematics Teachers integrated technology to develop their TPACK. The study was conducted among the twenty-seven senior primary mathematics teachers in the Okahao educational circuit in the Omuasti region. The study utilized Vygotsky‘s (1978); Socio-cultural Theory, together with Mishra and Koehler (2006), and; the Technological Pedagogical Content Knowledge (TPACK) framework was used as a lens to analyse the data. The data were gathered through semi-structured questionnaires, semi-structured interviews, focus group interviews, and lesson observations. The study findings indicate that senior primary mathematics teachers utilize the available resources at their respective schools during their classroom instruction. The study further reveals that mathematics teachers exhibit a positive attitude toward the integration of technology. The study uncovers the intricate interplay between technological knowledge, pedagogical expertise, and content knowledge within the context of mathematics education. The findings reveal that while participants demonstrate a high level of proficiency in certain TPACK components such as CK, TK, PK, TPK, and PCK, they expressed a moderate level of expertise in TCK and TPCK. The study also identified challenges in TPACK development, particularly the need for subject specific technology training, lack of technological infrastructure, particularly advanced technology, as well as a deficiency in ICT knowledge. The importance of access to various technologies was emphasized, enabling teachers to seamlessly integrate technology into their practices and address diverse learning styles. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-04
A Combined Experimental and Computational Study of Hydridospirophosphorane Ligand Systems Featuring Halogenated Mandelic Acids
- Authors: Maritz, Marius Johann
- Date: 2023-12
- Subjects: Organic compounds -- Synthesis , Heterocyclic compounds , catalysis -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62096 , vital:71911
- Description: The search for new stereoselective catalysts remains important for the isolation of enantiomeric products from racemic mixtures. The need exists for these catalysts to be more efficient, to be more cost effective as well as be stable over time without undergoing changes in molecular structure and selectivity. The purpose of this research project was to experimentally synthesise and characterise asymmetric catalysts for the use in enantioselective synthesis. The catalysts consisted of the main group element phosphorous as central atom, with the phenyl rings of mandelic acid ligands monosubstituted with halogen atoms fluorine, chlorine and bromine in different configurations. Ligand binding resulted in the formation of hydridospirophosphorane structures, from which the molecular properties and binding geometry of these molecules could be explained by the theory of apicophilicity. Characterization was performed by NMR and IR spectroscopy as well as diffraction studies that provided the experimental crystal structures. The structural, energetic and spectroscopy results were compared to the theoretically obtained molecular properties using DFT analysis. Various interand intramolecular interactions that existed between molecules found in crystal packing environments were discussed. Additional properties that were investigated included modelling solvation effects, molecular orbital analysis, Hirshfeld surfaces, orbital and atomic energy and population analysis as well as ESP energy calculations with the optimized crystal structures as input. Molecular overlay comparisons were also performed between the experimental and optimized structures where the effectiveness of various DFT functionals and basis sets could be determined. The method with the best overall cost-to-accuracy ratio was found to be the triple-zeta def2-tzvp basis set with B3LYP functional theory and the addition of Grimme’s dispersion correction. Results indicated differences in crystal packing depending largely on the given halogen atoms present in the substituted phenyl rings, with differences observed in electronegativity and steric effects. One of the crystal systems showed additional interactions with solvent molecules, giving the impression that obtaining crystal void formation was possible. Alterations in the transition state activation energies between the isomers of each molecule were found to be present and supported the theory behind the mechanism of stereochemical induction. The studied compounds were therefore effective in isolating different enantiomeric ligands by means of energy differences between conformers and displayed unique catalytic properties resulting from the phosphorous main group element. The hydridospirophosphoranes conformers responsible for the lowest theoretically calculated activation energy induced crystallization as was seen by diffraction results for all compounds. Even as an intriguing observation, crystallization will largely depend on solubility rather than a specific conformer’s amount in solution. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Maritz, Marius Johann
- Date: 2023-12
- Subjects: Organic compounds -- Synthesis , Heterocyclic compounds , catalysis -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62096 , vital:71911
- Description: The search for new stereoselective catalysts remains important for the isolation of enantiomeric products from racemic mixtures. The need exists for these catalysts to be more efficient, to be more cost effective as well as be stable over time without undergoing changes in molecular structure and selectivity. The purpose of this research project was to experimentally synthesise and characterise asymmetric catalysts for the use in enantioselective synthesis. The catalysts consisted of the main group element phosphorous as central atom, with the phenyl rings of mandelic acid ligands monosubstituted with halogen atoms fluorine, chlorine and bromine in different configurations. Ligand binding resulted in the formation of hydridospirophosphorane structures, from which the molecular properties and binding geometry of these molecules could be explained by the theory of apicophilicity. Characterization was performed by NMR and IR spectroscopy as well as diffraction studies that provided the experimental crystal structures. The structural, energetic and spectroscopy results were compared to the theoretically obtained molecular properties using DFT analysis. Various interand intramolecular interactions that existed between molecules found in crystal packing environments were discussed. Additional properties that were investigated included modelling solvation effects, molecular orbital analysis, Hirshfeld surfaces, orbital and atomic energy and population analysis as well as ESP energy calculations with the optimized crystal structures as input. Molecular overlay comparisons were also performed between the experimental and optimized structures where the effectiveness of various DFT functionals and basis sets could be determined. The method with the best overall cost-to-accuracy ratio was found to be the triple-zeta def2-tzvp basis set with B3LYP functional theory and the addition of Grimme’s dispersion correction. Results indicated differences in crystal packing depending largely on the given halogen atoms present in the substituted phenyl rings, with differences observed in electronegativity and steric effects. One of the crystal systems showed additional interactions with solvent molecules, giving the impression that obtaining crystal void formation was possible. Alterations in the transition state activation energies between the isomers of each molecule were found to be present and supported the theory behind the mechanism of stereochemical induction. The studied compounds were therefore effective in isolating different enantiomeric ligands by means of energy differences between conformers and displayed unique catalytic properties resulting from the phosphorous main group element. The hydridospirophosphoranes conformers responsible for the lowest theoretically calculated activation energy induced crystallization as was seen by diffraction results for all compounds. Even as an intriguing observation, crystallization will largely depend on solubility rather than a specific conformer’s amount in solution. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Assessing land degradation and the effectiveness of calcrete bontveld rehabilitation in a grassridge PPC cement mining area using multi-sensor remotely sensed data and machine learning techniques
- Authors: Mpisane, Khanyisa
- Date: 2023-12
- Subjects: Land degradation -- South Africa , Environmental degradation , Mines and mineral resources -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62527 , vital:72821
- Description: This study uses multi-temporal remote sensing data to spatially visualise and quantify land degradation due to mining as well as Calcrete Bontveld rehabilitation at the Grassridge PPC Cement mine, Gqeberha formerly known as Port Elizabeth in the Eastern Cape, South Africa. Botanical field data is also used to verify the suasses of rehabilitation in the area. SPOT-6 and Landsat multi-spectral images were compared, and Support Vector Machine and Random Forest algorithms were used for classification in order to determine which yields more accurate results for a limestone mine. Support Vector Machine analysis using SPOT-6 images yielded the best results. This was due to the high spatial resolution of SPOT-6 compared to Landsat and Support Vector Machine classifier was able to classify images with fewer training points compared to Random Forest. The spatio-temporal land cover change at the mine was then determined between the years 2000, 2015 and 2020. Land cover classification is useful for monitoring land degradation and, in this case, was able to show the extent of rehabilitation success. For the year 2020, a 17% area was rehabilitated; however, the algorithm could not distinguish between unmined Calcrete Bontveld matrix and rehabilitation sites that were older than five years. The performed change detection also showed that 29.50% of unmined Calcrete Bontveld matrix had changed to “mature rehabilitation” (rehabilitation sites older than five years). Again, for this percentage in some areas the algorithm could not distinguish between the unmined Calcrete Bontveld matrix and rehabilitation sites that were older than five years due to high similarities between the two land cover types. Area changes of the different land cover classes could also be used to demonstrate how rehabilitation areas have matured over time and lead to the conclusion that most of the Calcrete Bontveld which was mined, has over the years been successfully rehabilitated. Vegetation analysis was conducted to further validate the rehabilitation success of Calcrete Bontveld matrix. Multivariant Detrended Correspondent Analysis showed that rehabilitation sites which were younger than five years (2–year-old rehabilitation plots that were sampled) had great dissimilarity to the natural unmined Calcrete Bontveld matrix and that rehabilitation sites older than five years, in this case 16–years older, had high similarity and resemblance to natural unmined Calcrete Bontveld matrix and therefore could be considered as being mature. This was a more definitive assessment as it considers all aspects of the vegetation. Species cover and species richness also showed that Calcrete Bontveld matrix rehabilitation sites which have been rehabilitated for more than 5 years had greater similarity to natural unmined vegetation compared to areas that have been rehabilitated for less than five years. This study, therefore, demonstrates that due to the high similarity between mature rehabilitation sites and unmined Calcrete Bontveld, rehabilitation has been successful. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Mpisane, Khanyisa
- Date: 2023-12
- Subjects: Land degradation -- South Africa , Environmental degradation , Mines and mineral resources -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62527 , vital:72821
- Description: This study uses multi-temporal remote sensing data to spatially visualise and quantify land degradation due to mining as well as Calcrete Bontveld rehabilitation at the Grassridge PPC Cement mine, Gqeberha formerly known as Port Elizabeth in the Eastern Cape, South Africa. Botanical field data is also used to verify the suasses of rehabilitation in the area. SPOT-6 and Landsat multi-spectral images were compared, and Support Vector Machine and Random Forest algorithms were used for classification in order to determine which yields more accurate results for a limestone mine. Support Vector Machine analysis using SPOT-6 images yielded the best results. This was due to the high spatial resolution of SPOT-6 compared to Landsat and Support Vector Machine classifier was able to classify images with fewer training points compared to Random Forest. The spatio-temporal land cover change at the mine was then determined between the years 2000, 2015 and 2020. Land cover classification is useful for monitoring land degradation and, in this case, was able to show the extent of rehabilitation success. For the year 2020, a 17% area was rehabilitated; however, the algorithm could not distinguish between unmined Calcrete Bontveld matrix and rehabilitation sites that were older than five years. The performed change detection also showed that 29.50% of unmined Calcrete Bontveld matrix had changed to “mature rehabilitation” (rehabilitation sites older than five years). Again, for this percentage in some areas the algorithm could not distinguish between the unmined Calcrete Bontveld matrix and rehabilitation sites that were older than five years due to high similarities between the two land cover types. Area changes of the different land cover classes could also be used to demonstrate how rehabilitation areas have matured over time and lead to the conclusion that most of the Calcrete Bontveld which was mined, has over the years been successfully rehabilitated. Vegetation analysis was conducted to further validate the rehabilitation success of Calcrete Bontveld matrix. Multivariant Detrended Correspondent Analysis showed that rehabilitation sites which were younger than five years (2–year-old rehabilitation plots that were sampled) had great dissimilarity to the natural unmined Calcrete Bontveld matrix and that rehabilitation sites older than five years, in this case 16–years older, had high similarity and resemblance to natural unmined Calcrete Bontveld matrix and therefore could be considered as being mature. This was a more definitive assessment as it considers all aspects of the vegetation. Species cover and species richness also showed that Calcrete Bontveld matrix rehabilitation sites which have been rehabilitated for more than 5 years had greater similarity to natural unmined vegetation compared to areas that have been rehabilitated for less than five years. This study, therefore, demonstrates that due to the high similarity between mature rehabilitation sites and unmined Calcrete Bontveld, rehabilitation has been successful. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Chemical analysis and biological activities of crude extracts and essential oil of selected medicinal plants from the Eastern Cape, South Africa, and Volta Region of Ghana
- Authors: Agbo, Irene Adzo
- Date: 2023-12
- Subjects: Medicinal plants , Lantana camara , Peptic ulcer -- Treatment , Traditional medicine - South Africa -- Eastern Cape , Traditional medicine -- Ghana
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62431 , vital:72728
- Description: Lantana camara and Khaya grandifoliola extracts are among many plants found traditionally effective for the treatment of wounds and ulcers. This study assessed the phytochemical content, isolation and identification of single compounds from methanol and ethyl acetate extracts of Lantana camara and Khaya grandifoliola. Further, the bioactivity testing including antioxidant, antimicrobial and cytoxicity of the extracts was done to confirm the wound healing potential discovered by the traditional healers. Materials and methods: Extraction was done successively using maceration method with 100 % ethyl acetate and 100 % methanol with a biomass-to-solvent ratio of 1:3 (w/v) to obtain L. camara ethyl acetate extracts of berry (ELB), flower (ELF) and leaf (ELL) and methanol extracts of MLB, MLF, MLL and K. grandifoliola ethyl acetate extracts of leaf (EKL), root (EKR) and stem bark (EKSB) and methanol extracts of MKL, MKR, MKSB respectively. L. camara leaf essential oil (EO) was extracted using the hydro-distillation method with a Clevenger apparatus. Total phytochemical content was assessed for each extract using spectrophotometric methods and a calibration curve of standards: bromocresol green method with atropine; Folin–Ciocalteu colorimetric method with gallic acid, aluminium chloride colorimetric method with quercetin and concentrated sulphuric acid chloroform with linalool for total alkaloid, phenolic, flavonoid and terpenoid contents respectively. Single compound isolation and purification was conducted using chromatographic techniques. Elucidation of single compounds was done using spectrometric method, high resolution- mass spectrometry, and one and two-dimensional (1D and 2D)-NMR. Stereochemistry of each compound was confirmed using electronic circular dichroism spectra. A Crystalline compound was identified by single crystal X-ray diffraction using CuKα-radiation. In vitro bioactivities were assessed with methods such as 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide, free radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl, inhibitory effect on nitric oxide production in lipopolysaccharide-activated RAW 264.7 macrophages, and 96-well plate micro dilution for cytotoxicity, ant-inflammatory and antimicrobial activity testing. Results: Methanol extracts of both plants retained high phytochemical concentrations of all the phytoconstituents investigated compared with the ethyl acetate extracts which retained lower concentrations. The results of the L. camara methanol extracts include; total alkaloid content (TAC) (2.05±0.18, 1.87±1.54 and 2.60±1.10 mg AEQ/100 mg); total phenolic content (TPC) (14.05±4.04, 34.59±3.01 and 18.58±1.87 mg GAEQ/100 mg); the total flavonoid content(TFC) of flower (12.45±1.87, 20.41±2.69 and mg QEQ/100 mg); total terpenoids (TTC) (20.74±2.34, 20.74±2.34 and 15.97±1.19 mg LIN EQ/100mg) of MLB, MLF and MLL respectively. Whereas that of the K. grandifoliola methanol extracts include; TAC (7.32±0.14,8.49±0.34, 10.67±0.22 mg AEQ/100 mg); TPC (37.49±1.40, 44.41±0.69, 53.57±1.50 mgGAEQ/100 mg); TFC (6.54±0.55, 9.58±0.89 and 10.26±0.92 mg QEQ/100 mg); TTC(10.16±1.41, 35.78±2.14 and 23.45±1.76 mg LIN EQ/100mg) of MKL, MKR and MKSB respectively. The major components of essential oil, out of the 71 constituents identified include Davanone D (32.91 %), Caryophyllene (5.07 %), Nerolidol 2 (3.56 %) and GermacreneD (3.13 %). Compounds 3.47 was isolated from the methanol extract of L. camara flowers. This compound is reported for the first time from the L. camara flower extract. Two compounds, compounds 4.23, and 4.26, were isolated from the methanol extract of K. grandifoliola roots, compound 4.22 was isolated from the ethyl acetate root extract while compounds 4.24 and 4.25 were isolated from the ethyl acetate stem bark extract as isomers in a mixture. Compounds 4.22 and 4.23 are reported from K. grandifoliola root for the first time. The isolated compounds (compounds 3.47 and 4.23) were nontoxic to the Vero cell line and this may contribute to possible stimulation of cell proliferation, promoting wound healing. Cytotoxicity describes extract virulence to Vero cell line. MLF and ELB were found nontoxic even at the highest concentration of 200 μg/mL. The MKSB and MKR, as well as the EKSB were nontoxic. Antioxidant activity results, described by the percentage inhibition in the DPPH assay, showed that MLF and MKSB had the highest antioxidant activities compared with the ascorbic acid standard, with IC50 of 38.68±5.09 and 37.03±11.95 μg/mL for L. camara and K. grandifoliola respectively. ELB exhibited a significant anti-inflammatory activity inhibiting NO• radical generation in the LPS-stimulated RAW 264.7 macrophages at concentration ranging from 50 and 100 μg/mL. EKSB and MKR showed significant anti-inflammatory activity at 100 and 200 μg/ml respectively. ELL and ELF demonstrated potent growth inhibition against S. pyogenes with an MIC value ≤ 0.125 mg/mL, while the MICs of the ELB and MLL were 0.5 mg/mL and 2 mg/mL respectively. MKSB and MKR and EKSB extract exhibited an effective growth inhibition against S. aureus with MIC of 1 mg/mL. The growth of S. pyogenes was supressed by both ethyl acetate and methanol extracts of all plant parts tested with MIC ranging from 0.25–2 mg/mL. Conclusion: The potent bioactivity shown in the results of the cytotoxicity, antioxidant activity, anti-inflammatory and antimicrobial activity testing, and the nontoxic singlecompounds of L. camara and K. grandifoliola extracts led to the conclusion that the two plants had wound healing potential. The study therefore confirmed their traditional uses for treatment of wounds. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Agbo, Irene Adzo
- Date: 2023-12
- Subjects: Medicinal plants , Lantana camara , Peptic ulcer -- Treatment , Traditional medicine - South Africa -- Eastern Cape , Traditional medicine -- Ghana
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62431 , vital:72728
- Description: Lantana camara and Khaya grandifoliola extracts are among many plants found traditionally effective for the treatment of wounds and ulcers. This study assessed the phytochemical content, isolation and identification of single compounds from methanol and ethyl acetate extracts of Lantana camara and Khaya grandifoliola. Further, the bioactivity testing including antioxidant, antimicrobial and cytoxicity of the extracts was done to confirm the wound healing potential discovered by the traditional healers. Materials and methods: Extraction was done successively using maceration method with 100 % ethyl acetate and 100 % methanol with a biomass-to-solvent ratio of 1:3 (w/v) to obtain L. camara ethyl acetate extracts of berry (ELB), flower (ELF) and leaf (ELL) and methanol extracts of MLB, MLF, MLL and K. grandifoliola ethyl acetate extracts of leaf (EKL), root (EKR) and stem bark (EKSB) and methanol extracts of MKL, MKR, MKSB respectively. L. camara leaf essential oil (EO) was extracted using the hydro-distillation method with a Clevenger apparatus. Total phytochemical content was assessed for each extract using spectrophotometric methods and a calibration curve of standards: bromocresol green method with atropine; Folin–Ciocalteu colorimetric method with gallic acid, aluminium chloride colorimetric method with quercetin and concentrated sulphuric acid chloroform with linalool for total alkaloid, phenolic, flavonoid and terpenoid contents respectively. Single compound isolation and purification was conducted using chromatographic techniques. Elucidation of single compounds was done using spectrometric method, high resolution- mass spectrometry, and one and two-dimensional (1D and 2D)-NMR. Stereochemistry of each compound was confirmed using electronic circular dichroism spectra. A Crystalline compound was identified by single crystal X-ray diffraction using CuKα-radiation. In vitro bioactivities were assessed with methods such as 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide, free radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl, inhibitory effect on nitric oxide production in lipopolysaccharide-activated RAW 264.7 macrophages, and 96-well plate micro dilution for cytotoxicity, ant-inflammatory and antimicrobial activity testing. Results: Methanol extracts of both plants retained high phytochemical concentrations of all the phytoconstituents investigated compared with the ethyl acetate extracts which retained lower concentrations. The results of the L. camara methanol extracts include; total alkaloid content (TAC) (2.05±0.18, 1.87±1.54 and 2.60±1.10 mg AEQ/100 mg); total phenolic content (TPC) (14.05±4.04, 34.59±3.01 and 18.58±1.87 mg GAEQ/100 mg); the total flavonoid content(TFC) of flower (12.45±1.87, 20.41±2.69 and mg QEQ/100 mg); total terpenoids (TTC) (20.74±2.34, 20.74±2.34 and 15.97±1.19 mg LIN EQ/100mg) of MLB, MLF and MLL respectively. Whereas that of the K. grandifoliola methanol extracts include; TAC (7.32±0.14,8.49±0.34, 10.67±0.22 mg AEQ/100 mg); TPC (37.49±1.40, 44.41±0.69, 53.57±1.50 mgGAEQ/100 mg); TFC (6.54±0.55, 9.58±0.89 and 10.26±0.92 mg QEQ/100 mg); TTC(10.16±1.41, 35.78±2.14 and 23.45±1.76 mg LIN EQ/100mg) of MKL, MKR and MKSB respectively. The major components of essential oil, out of the 71 constituents identified include Davanone D (32.91 %), Caryophyllene (5.07 %), Nerolidol 2 (3.56 %) and GermacreneD (3.13 %). Compounds 3.47 was isolated from the methanol extract of L. camara flowers. This compound is reported for the first time from the L. camara flower extract. Two compounds, compounds 4.23, and 4.26, were isolated from the methanol extract of K. grandifoliola roots, compound 4.22 was isolated from the ethyl acetate root extract while compounds 4.24 and 4.25 were isolated from the ethyl acetate stem bark extract as isomers in a mixture. Compounds 4.22 and 4.23 are reported from K. grandifoliola root for the first time. The isolated compounds (compounds 3.47 and 4.23) were nontoxic to the Vero cell line and this may contribute to possible stimulation of cell proliferation, promoting wound healing. Cytotoxicity describes extract virulence to Vero cell line. MLF and ELB were found nontoxic even at the highest concentration of 200 μg/mL. The MKSB and MKR, as well as the EKSB were nontoxic. Antioxidant activity results, described by the percentage inhibition in the DPPH assay, showed that MLF and MKSB had the highest antioxidant activities compared with the ascorbic acid standard, with IC50 of 38.68±5.09 and 37.03±11.95 μg/mL for L. camara and K. grandifoliola respectively. ELB exhibited a significant anti-inflammatory activity inhibiting NO• radical generation in the LPS-stimulated RAW 264.7 macrophages at concentration ranging from 50 and 100 μg/mL. EKSB and MKR showed significant anti-inflammatory activity at 100 and 200 μg/ml respectively. ELL and ELF demonstrated potent growth inhibition against S. pyogenes with an MIC value ≤ 0.125 mg/mL, while the MICs of the ELB and MLL were 0.5 mg/mL and 2 mg/mL respectively. MKSB and MKR and EKSB extract exhibited an effective growth inhibition against S. aureus with MIC of 1 mg/mL. The growth of S. pyogenes was supressed by both ethyl acetate and methanol extracts of all plant parts tested with MIC ranging from 0.25–2 mg/mL. Conclusion: The potent bioactivity shown in the results of the cytotoxicity, antioxidant activity, anti-inflammatory and antimicrobial activity testing, and the nontoxic singlecompounds of L. camara and K. grandifoliola extracts led to the conclusion that the two plants had wound healing potential. The study therefore confirmed their traditional uses for treatment of wounds. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Dietary assessment of Cape Gannets (Morus capensis) and African Penguins (Spheniscus demersus) in Algoa Bay using molecular scatology
- Bowmaker - Falconer, Kezia, Von Der Heyden, Sophie
- Authors: Bowmaker - Falconer, Kezia , Von Der Heyden, Sophie
- Date: 2023-12
- Subjects: Gannets , Gannets -- Food , Sea birds -- South Africa -- Bird Island, Algoa Bay.
- Language: English
- Type: Master's theses
- Identifier: http://hdl.handle.net/10948/62420 , vital:72675
- Description: Seabirds are important marine sentinels, providing valuable information about ecosystem health and condition. Dietary studies of seabirds can inform on ecosystem functioning through identifying the condition and changes occurring in their surrounding environment. Dietary studies are also crucial as they can identify threats that seabirds face. Until recently, the diets of southern African endemic and Endangered Cape Gannets Morus capensis and African Penguins Spheniscus demersus were solely investigated through stomach content analyses, which allows for the identification and quantification of prey remains. To overcome some of the limitations associated with stomach content analysis, stable isotope and fatty acid analyses were proposed. However, these methods still require bird handling and thus impose some stress on the birds. DNA metabarcoding of faecal matter shows promise as a completely noninvasive method for seabird dietary studies. This thesis first examined whether DNA metabarcoding could be used to determine the diet of Cape Gannet and African Penguin breeding in Algoa Bay, South Africa. Then, this method was used to investigate the influence of intrinsic (both seabird species) and extrinsic (African Penguins) factors on the diet of the two seabird species. For the first data chapter, stomach content samples and faecal matter were collected concurrently from breeding Cape Gannets and African Penguins on Bird Island. DNA was successfully extracted from most faecal matter samples and the primers (18S_SSU, 16S_Fish) used for group, taxa and fish prey identification allowed amplification of prey DNA for both study species. A similar piscivorous diet was determined by both dietary methods for Cape Gannets with Sardine Sardinops sagax and Atlantic Saury Scomberesox saurus dominating the diet. Sardine also dominated the African Penguin diet in both dietary methods. In addition, DNA metabarcoding in African Penguins revealed a more diverse diet compared to the one determined by stomach content analysis. This was likely due to the limitations on the allowed number of stomach content samples to be collected for that Endangered species. Non-invasive DNA metabarcoding of faecal matter was then used to investigate whether the diet varied with breeding stages (incubation, chick-rearing) and age classes (chick-rearing adults, chicks) in both seabird species, but also breeding colonies (Algoa Bay: Bird Island, St Croix Island) in African Penguins. DNA metabarcoding revealed that breeding stages influenced the diet of Cape Gannets and African Penguins on Bird Island where prey species diversity was greater for incubating adults. On the contrary, the diet of incubating and chick-rearing penguins on St Croix Island was similar. When comparing the diet of African Penguins between Bird Island and St Croix Island, there was an increased overlap in diet composition between incubating and chick-rearing adults on St Croix Island when compared to Bird Island. Importantly, DNA metabarcoding indicated an increase in fishery interactions in Algoa Bay, particularly for Cape Gannets and the hake Merluccius spp. fishery, where the contribution of hake to chick-rearing adults and chick diet was considerably greater than incubating adult diet. In this study, I showed that DNA metabarcoding of faecal matter provides an opportunity for non-invasive dietary studies in two southern African endemic and Endangered seabird species. Incorporating non-invasive methods as a complement to other dietary methods for monitoring seabird trophic ecology is crucial when considering the worsening status of several seabird species. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Bowmaker - Falconer, Kezia , Von Der Heyden, Sophie
- Date: 2023-12
- Subjects: Gannets , Gannets -- Food , Sea birds -- South Africa -- Bird Island, Algoa Bay.
- Language: English
- Type: Master's theses
- Identifier: http://hdl.handle.net/10948/62420 , vital:72675
- Description: Seabirds are important marine sentinels, providing valuable information about ecosystem health and condition. Dietary studies of seabirds can inform on ecosystem functioning through identifying the condition and changes occurring in their surrounding environment. Dietary studies are also crucial as they can identify threats that seabirds face. Until recently, the diets of southern African endemic and Endangered Cape Gannets Morus capensis and African Penguins Spheniscus demersus were solely investigated through stomach content analyses, which allows for the identification and quantification of prey remains. To overcome some of the limitations associated with stomach content analysis, stable isotope and fatty acid analyses were proposed. However, these methods still require bird handling and thus impose some stress on the birds. DNA metabarcoding of faecal matter shows promise as a completely noninvasive method for seabird dietary studies. This thesis first examined whether DNA metabarcoding could be used to determine the diet of Cape Gannet and African Penguin breeding in Algoa Bay, South Africa. Then, this method was used to investigate the influence of intrinsic (both seabird species) and extrinsic (African Penguins) factors on the diet of the two seabird species. For the first data chapter, stomach content samples and faecal matter were collected concurrently from breeding Cape Gannets and African Penguins on Bird Island. DNA was successfully extracted from most faecal matter samples and the primers (18S_SSU, 16S_Fish) used for group, taxa and fish prey identification allowed amplification of prey DNA for both study species. A similar piscivorous diet was determined by both dietary methods for Cape Gannets with Sardine Sardinops sagax and Atlantic Saury Scomberesox saurus dominating the diet. Sardine also dominated the African Penguin diet in both dietary methods. In addition, DNA metabarcoding in African Penguins revealed a more diverse diet compared to the one determined by stomach content analysis. This was likely due to the limitations on the allowed number of stomach content samples to be collected for that Endangered species. Non-invasive DNA metabarcoding of faecal matter was then used to investigate whether the diet varied with breeding stages (incubation, chick-rearing) and age classes (chick-rearing adults, chicks) in both seabird species, but also breeding colonies (Algoa Bay: Bird Island, St Croix Island) in African Penguins. DNA metabarcoding revealed that breeding stages influenced the diet of Cape Gannets and African Penguins on Bird Island where prey species diversity was greater for incubating adults. On the contrary, the diet of incubating and chick-rearing penguins on St Croix Island was similar. When comparing the diet of African Penguins between Bird Island and St Croix Island, there was an increased overlap in diet composition between incubating and chick-rearing adults on St Croix Island when compared to Bird Island. Importantly, DNA metabarcoding indicated an increase in fishery interactions in Algoa Bay, particularly for Cape Gannets and the hake Merluccius spp. fishery, where the contribution of hake to chick-rearing adults and chick diet was considerably greater than incubating adult diet. In this study, I showed that DNA metabarcoding of faecal matter provides an opportunity for non-invasive dietary studies in two southern African endemic and Endangered seabird species. Incorporating non-invasive methods as a complement to other dietary methods for monitoring seabird trophic ecology is crucial when considering the worsening status of several seabird species. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Evaluating antidiabetic properties of selected African medicinal plants in a cell-based model
- Sirkhotte, Saeedah, Reddy, Shanika
- Authors: Sirkhotte, Saeedah , Reddy, Shanika
- Date: 2023-12
- Subjects: Medicinal plants -- South Africa , Insulin resistance , Gluconeogenesis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62600 , vital:72827
- Description: The World Health Organisation lists diabetes as one of the major non-communicable diseases affecting the world, and its prevalence is expected to increase rapidly. Type II diabetes mellitus (T2DM) is characterised by insulin resistance and impaired blood glucose control. T2DM is of growing concern within South Africa, with 10.8% of the population currently diagnosed. The popularity, as well as availability, of traditional plant-based medicine in South Africa, might provide a solution. Antidiabetic potential is commonly tested by in vitro assays, however the methods to test this potential via gluconeogenesis are limited. This project aimed to optimise an in vitro hepatic gluconeogenesis model. In addition, this project aimed to determine the antidiabetic properties of Prunus africana, Hypoxis stellipilis, and Eriocephalus africanus by in vitro analysis. These properties were examined in human hepatoma cells (C3A cell line) and rat pancreatic cells (INS1 cell line) and methods included: cytotoxicity analysis, Amplex® red glucose oxidase assay, antibody staining, gene expression analysis by RT-qPCR, oxidative stress analysis, and calcium signaling for insulin release. Insulin resistance was successfully induced by exposing C3A hepatocarcinoma cells to a combination treatment of 50 μM dexamethasone, 1.25 mM fructose and 0.125 mM palmitic acid for a period of three days. Thereafter, gluconeogenesis was assessed using the Amplex® red glucose oxidase assay. The established model was effective in inducing insulin resistance and upregulating gluconeogenesis. Of the tested plant extracts, H. stellipilis showed the most potential as an antidiabetic treatment. It had low toxicity, significantly decreased hepatic glucose production and reduced the amount of phosphoenolpyruvate carboxykinase (PCK) and well as PCK gene expression, and reduced lipid content and reactive oxygen species (ROS) in the C3A cell line. H. stellipilis increased calcium signalling in INS1 rat insulinoma cells, however there was a decrease in expression of genes for insulin and glucose transporter 2 after 6 hr exposure. H. stellipilis appears be beneficial as an antidiabetic treatment. Although antidiabetic studies have been done on other Hypoxis species, this is the first study on the effects of H. stellipilis on gluconeogenesis and diabetes. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Sirkhotte, Saeedah , Reddy, Shanika
- Date: 2023-12
- Subjects: Medicinal plants -- South Africa , Insulin resistance , Gluconeogenesis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62600 , vital:72827
- Description: The World Health Organisation lists diabetes as one of the major non-communicable diseases affecting the world, and its prevalence is expected to increase rapidly. Type II diabetes mellitus (T2DM) is characterised by insulin resistance and impaired blood glucose control. T2DM is of growing concern within South Africa, with 10.8% of the population currently diagnosed. The popularity, as well as availability, of traditional plant-based medicine in South Africa, might provide a solution. Antidiabetic potential is commonly tested by in vitro assays, however the methods to test this potential via gluconeogenesis are limited. This project aimed to optimise an in vitro hepatic gluconeogenesis model. In addition, this project aimed to determine the antidiabetic properties of Prunus africana, Hypoxis stellipilis, and Eriocephalus africanus by in vitro analysis. These properties were examined in human hepatoma cells (C3A cell line) and rat pancreatic cells (INS1 cell line) and methods included: cytotoxicity analysis, Amplex® red glucose oxidase assay, antibody staining, gene expression analysis by RT-qPCR, oxidative stress analysis, and calcium signaling for insulin release. Insulin resistance was successfully induced by exposing C3A hepatocarcinoma cells to a combination treatment of 50 μM dexamethasone, 1.25 mM fructose and 0.125 mM palmitic acid for a period of three days. Thereafter, gluconeogenesis was assessed using the Amplex® red glucose oxidase assay. The established model was effective in inducing insulin resistance and upregulating gluconeogenesis. Of the tested plant extracts, H. stellipilis showed the most potential as an antidiabetic treatment. It had low toxicity, significantly decreased hepatic glucose production and reduced the amount of phosphoenolpyruvate carboxykinase (PCK) and well as PCK gene expression, and reduced lipid content and reactive oxygen species (ROS) in the C3A cell line. H. stellipilis increased calcium signalling in INS1 rat insulinoma cells, however there was a decrease in expression of genes for insulin and glucose transporter 2 after 6 hr exposure. H. stellipilis appears be beneficial as an antidiabetic treatment. Although antidiabetic studies have been done on other Hypoxis species, this is the first study on the effects of H. stellipilis on gluconeogenesis and diabetes. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Insights into the relative abundance, demographics and behaviour of sea turtles along the east coast of South Africa
- Authors: dos Santos, Natalie Aida
- Date: 2023-12
- Subjects: Sea turtles -- Conservation -- South Africa , Sea turtles -- South Africa , Photogrammetry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62495 , vital:72778
- Description: Sea turtles are ecologically important species that have endured a history of overexploitation. Combined with their long, complex life cycles and ongoing anthropogenic pressures, they remain conservation-dependent. Conservation efforts worldwide focus on sea turtle nesting beach protection, however, comprehensive management strategies require an understanding of their lives at sea which are often spent in distant waters. This understanding is hindered by the relative challenges of in-water studies. South Africa has also focused research and conservation efforts on nesting adult female loggerheads (Caretta caretta) and leatherbacks (Dermochelys coriacea), largely overlooking the species or age classes remaining at sea. Green turtles (Chelonia mydas), hawksbills (Eretmochelys imbricata) and non-breeding loggerheads are frequently stranded and rehabilitated by aquaria, and observed by recreational divers on reefs, suggesting year-round residency along the country’s entire seaboard. Recent technological advancements in photo-identification methods for sea turtles, underwater photography and internet connectivity allowing even recreational divers to become citizen scientists now place us on the verge of an exciting opportunity to unravel the cryptic in-water ecology of these species. The overall aim of this study was to conduct the first assessment of relative abundance, demographics, distribution, and behaviour of sea turtles on reefs within the iSimangaliso and Aliwal Shoal Marine Protected Areas (MPAs) on the east coast of South Africa. A robust photo-identification database was established from research dives, voluntourism and citizen science contributions over a two-year period. From 1057 sightings in the two MPAs, a total of 227 individual sea turtles were identified constituting three species (green turtles: n = 120; hawksbills: n = 46; loggerheads: n = 61). Their relative abundance was proportional to the overall sizes of the South West Indian Ocean (SWIO) populations (green turtles > hawksbills > loggerheads > leatherbacks). However, sightings per unit effort (SPUE) showed that loggerheads were more prevalent than hawksbills in iSimangaliso, likely due to its proximity to this loggerhead rookery. Reefs supported mixed size aggregations with juvenile to adult-sized green turtles (straight carapace lengths, SCLs of 44.9–99.2 cm), whilst hawksbills were mostly juveniles or subadults (SCL range: 37.4–73.4 cm) and loggerheads were mostly adult-sized (SCL range: 66.9–81 cm). Adult sex ratios were slightly female-biased but not significantly different from 1:1. The longest minimum residence periods recorded for individual subadult green and hawksbill turtles (676 and 675 days respectively) and adult-sized loggerheads (621 days) were suggestive of residency. Resident sea turtle activities were typical; they wereobserved foraging, resting, cleaning and interacting year-round, whilst only loggerheads and leatherbacks were observed in breeding behaviour (e.g., patrolling and mating) just after the seasonal arrival of transient individuals. This study thus reveals that the east coast of South Africa hosts regionally important resident and transient sea turtle aggregations with some of the highest SPUE results recorded for the region. This first attempt at monitoring foraging grounds using a variety of techniques and stakeholder groups can serve as the baseline assessment for future work and the foundation for a long-term in-water monitoring programme, allowing for expansion along the entire coastline. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: dos Santos, Natalie Aida
- Date: 2023-12
- Subjects: Sea turtles -- Conservation -- South Africa , Sea turtles -- South Africa , Photogrammetry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62495 , vital:72778
- Description: Sea turtles are ecologically important species that have endured a history of overexploitation. Combined with their long, complex life cycles and ongoing anthropogenic pressures, they remain conservation-dependent. Conservation efforts worldwide focus on sea turtle nesting beach protection, however, comprehensive management strategies require an understanding of their lives at sea which are often spent in distant waters. This understanding is hindered by the relative challenges of in-water studies. South Africa has also focused research and conservation efforts on nesting adult female loggerheads (Caretta caretta) and leatherbacks (Dermochelys coriacea), largely overlooking the species or age classes remaining at sea. Green turtles (Chelonia mydas), hawksbills (Eretmochelys imbricata) and non-breeding loggerheads are frequently stranded and rehabilitated by aquaria, and observed by recreational divers on reefs, suggesting year-round residency along the country’s entire seaboard. Recent technological advancements in photo-identification methods for sea turtles, underwater photography and internet connectivity allowing even recreational divers to become citizen scientists now place us on the verge of an exciting opportunity to unravel the cryptic in-water ecology of these species. The overall aim of this study was to conduct the first assessment of relative abundance, demographics, distribution, and behaviour of sea turtles on reefs within the iSimangaliso and Aliwal Shoal Marine Protected Areas (MPAs) on the east coast of South Africa. A robust photo-identification database was established from research dives, voluntourism and citizen science contributions over a two-year period. From 1057 sightings in the two MPAs, a total of 227 individual sea turtles were identified constituting three species (green turtles: n = 120; hawksbills: n = 46; loggerheads: n = 61). Their relative abundance was proportional to the overall sizes of the South West Indian Ocean (SWIO) populations (green turtles > hawksbills > loggerheads > leatherbacks). However, sightings per unit effort (SPUE) showed that loggerheads were more prevalent than hawksbills in iSimangaliso, likely due to its proximity to this loggerhead rookery. Reefs supported mixed size aggregations with juvenile to adult-sized green turtles (straight carapace lengths, SCLs of 44.9–99.2 cm), whilst hawksbills were mostly juveniles or subadults (SCL range: 37.4–73.4 cm) and loggerheads were mostly adult-sized (SCL range: 66.9–81 cm). Adult sex ratios were slightly female-biased but not significantly different from 1:1. The longest minimum residence periods recorded for individual subadult green and hawksbill turtles (676 and 675 days respectively) and adult-sized loggerheads (621 days) were suggestive of residency. Resident sea turtle activities were typical; they wereobserved foraging, resting, cleaning and interacting year-round, whilst only loggerheads and leatherbacks were observed in breeding behaviour (e.g., patrolling and mating) just after the seasonal arrival of transient individuals. This study thus reveals that the east coast of South Africa hosts regionally important resident and transient sea turtle aggregations with some of the highest SPUE results recorded for the region. This first attempt at monitoring foraging grounds using a variety of techniques and stakeholder groups can serve as the baseline assessment for future work and the foundation for a long-term in-water monitoring programme, allowing for expansion along the entire coastline. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Integrating state-space modelling and systematic conservation planning to recommend penguin-fishery management zones in Algoa Bay, South Africa
- Stockdale, Victoria, Goodall, Victoria, Clifford-Holmes, Jia
- Authors: Stockdale, Victoria , Goodall, Victoria , Clifford-Holmes, Jia
- Date: 2023-12
- Subjects: Biodiversity conservation -- South Africa -- Port Elizabeth , Natural resource conservation , Marine ecology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62611 , vital:72828
- Description: Direct anthropogenic impacts on vulnerable marine ecosystems are growing and require effective conservation measures. Integrating the cost impacts of conservation interventions and optimising the spatiotemporal scale of management interventions may improve cohesion between opposing marine users. This study aimed to integrate spatial and temporal models to advise dynamic penguin-fishery management plans in Algoa Bay, off Gqeberha, South Africa, that would maximise penguin foraging success while minimising the impact on the fishing industry. Determining the foraging locations important to breeding penguins is fundamental when understanding the relationship between fisheries and prey availability. Using Global Positioning System (GPS) data gathered from feeding trips of breeding African penguins between 2012 and 2017, and a hidden Markov model, three behavioural states (foraging, commuting, transitioning) were inferred and used as conservation targets in spatial prioritisation using the prioritizr package in R. The cost to the fishery was estimated using the catch of pelagic fish by the fishing industry between 2012 and 2015 as the proxy. The energetic cost to penguins was the distance they travelled from their breeding colony. Nine prioritisation scenarios, varying in levels of conservation for penguins, spatial cohesion and costs to fisheries, were developed using all year’s combined data to explore an ‘optimal’ closure configuration. The optimal closure was determined as an area which met the targets for penguin conservation, with a low cost to the fishery, close to the breeding colony and spatially clumped. The best solution from each scenario was isolated and the solution for the conservation target of 20% foraging habitat, 10% commuting habitat and 10% transitioning habitat and a boundary penalty of 0.01 (a dimensionless value that is used to reduce spatial fragmentation – increasing the value of the parameter signals that it is important to minimise the total exposed boundary of the prioritisation by favouring solutions where units are clumped together) was chosen as the optimal closure. This configuration was used as a static closure and applied to individual fishing seasons to estimate how the cost of a static closure design to the fishery would vary between seasons. Subsequently, a dynamic closure was designed using the same optimal configuration criteria every year, and the cost to the fishing industry was compared seasonally with the cost of a static closure. The cost to fisheries of dynamic closures was consistently lower than that of a static closure and the area required to meet the penguin feeding targets was drastically reduced. While dynamic closure scenarios show promise to minimise costs to the industry while meeting penguin conservation targets, these configurations were designed retrospectively with data collected after the end of the fishery seasons. For efficient management, the closures need to be designed by using data collected at an appropriate temporal scale. For that, the critical missing dimension to this study is the addition of real-time data on pelagic fish positions, areas of fishing intensity and sites of penguin foraging to create appropriate recommendations for up-to-date fishery exclusion zones. Therefore, the priority now is to explore methods of collecting real-time data on pelagic fish abundance, feeding behaviour of penguins at sea, site and mass of pelagic fishery catch, and using these data to delineate real-time, dynamic closures, coupled with a governance and management strategy that can implement dynamic closures. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Stockdale, Victoria , Goodall, Victoria , Clifford-Holmes, Jia
- Date: 2023-12
- Subjects: Biodiversity conservation -- South Africa -- Port Elizabeth , Natural resource conservation , Marine ecology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62611 , vital:72828
- Description: Direct anthropogenic impacts on vulnerable marine ecosystems are growing and require effective conservation measures. Integrating the cost impacts of conservation interventions and optimising the spatiotemporal scale of management interventions may improve cohesion between opposing marine users. This study aimed to integrate spatial and temporal models to advise dynamic penguin-fishery management plans in Algoa Bay, off Gqeberha, South Africa, that would maximise penguin foraging success while minimising the impact on the fishing industry. Determining the foraging locations important to breeding penguins is fundamental when understanding the relationship between fisheries and prey availability. Using Global Positioning System (GPS) data gathered from feeding trips of breeding African penguins between 2012 and 2017, and a hidden Markov model, three behavioural states (foraging, commuting, transitioning) were inferred and used as conservation targets in spatial prioritisation using the prioritizr package in R. The cost to the fishery was estimated using the catch of pelagic fish by the fishing industry between 2012 and 2015 as the proxy. The energetic cost to penguins was the distance they travelled from their breeding colony. Nine prioritisation scenarios, varying in levels of conservation for penguins, spatial cohesion and costs to fisheries, were developed using all year’s combined data to explore an ‘optimal’ closure configuration. The optimal closure was determined as an area which met the targets for penguin conservation, with a low cost to the fishery, close to the breeding colony and spatially clumped. The best solution from each scenario was isolated and the solution for the conservation target of 20% foraging habitat, 10% commuting habitat and 10% transitioning habitat and a boundary penalty of 0.01 (a dimensionless value that is used to reduce spatial fragmentation – increasing the value of the parameter signals that it is important to minimise the total exposed boundary of the prioritisation by favouring solutions where units are clumped together) was chosen as the optimal closure. This configuration was used as a static closure and applied to individual fishing seasons to estimate how the cost of a static closure design to the fishery would vary between seasons. Subsequently, a dynamic closure was designed using the same optimal configuration criteria every year, and the cost to the fishing industry was compared seasonally with the cost of a static closure. The cost to fisheries of dynamic closures was consistently lower than that of a static closure and the area required to meet the penguin feeding targets was drastically reduced. While dynamic closure scenarios show promise to minimise costs to the industry while meeting penguin conservation targets, these configurations were designed retrospectively with data collected after the end of the fishery seasons. For efficient management, the closures need to be designed by using data collected at an appropriate temporal scale. For that, the critical missing dimension to this study is the addition of real-time data on pelagic fish positions, areas of fishing intensity and sites of penguin foraging to create appropriate recommendations for up-to-date fishery exclusion zones. Therefore, the priority now is to explore methods of collecting real-time data on pelagic fish abundance, feeding behaviour of penguins at sea, site and mass of pelagic fishery catch, and using these data to delineate real-time, dynamic closures, coupled with a governance and management strategy that can implement dynamic closures. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Investigating the effect of peptide-functionalized gold nanoparticles on colon cancer cells
- Authors: Ramagoma, Rolivhuwa Bishop
- Date: 2023-12
- Subjects: Colon (Anatomy) -- Cancer -- Research , Colon (Anatomy) -- Cancer -- Treatment , Nanoparticles
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62564 , vital:72824
- Description: Colon cancer like any other cancer is a condition in which cells grow uncontrollably and may even spread to other regions of the body through metastasis. Colon cancer was ranked the second leading cause of cancer related deaths worldwide in 2018. Research to advance treatment of cancer keeps advancing daily, However, a big challenge is drug-induced side effects due to toxicity against normal body cells. Therefore, the development of controlled release technologies in conjunction with targeted drug delivery may provide a more efficient and less dangerous approach to overcome the limits of traditional chemotherapy. Including the creation of nanoscale delivery vehicles capable of directing the release of chemotherapeutic drugs into cancer cells only. This study aims to investigate p14 peptide that would specifically target colorectal cancer cells and not normal body cells to develop a targeted drug delivery system using gold nanoparticles. This study serves as a pilot study of the primary aim. To achieve this, the effect of the peptide p14 and peptide functionalized gold nanoparticles (p14-AuNP) on colon cancer cells (HT-29) and normal epithelial cells (KMST-6) was determined. Firstly, gold nanoparticles were chemically synthesised and then functionalized with p14 peptide through Polyethylene glycol. Then assessment of their effect through in vitro cytotoxicity assay (MTT) and gene expression analysis (RT-qPCR) was conducted. Nanoparticles’ synthesis and functionalization was performed and confirmed: In vitro cytotoxicity through MTT assay was successfully conducted and p14-AuNP showed toxicity against colon cancer cells and lesser toxicity towards normal cells as compared to 5-Flourouracil (commercially approved drug for colon cancer treatment). Gene expression analysis revealed that apoptosis was induced in both cell lines by p14-AuNP either through upregulation of caspase 3, 7 and/or BCL2. A cell survival gene, AKT1, also had significant effect on this. CDC42 was downregulated which indicates that cell proliferation was inhibited. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Ramagoma, Rolivhuwa Bishop
- Date: 2023-12
- Subjects: Colon (Anatomy) -- Cancer -- Research , Colon (Anatomy) -- Cancer -- Treatment , Nanoparticles
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62564 , vital:72824
- Description: Colon cancer like any other cancer is a condition in which cells grow uncontrollably and may even spread to other regions of the body through metastasis. Colon cancer was ranked the second leading cause of cancer related deaths worldwide in 2018. Research to advance treatment of cancer keeps advancing daily, However, a big challenge is drug-induced side effects due to toxicity against normal body cells. Therefore, the development of controlled release technologies in conjunction with targeted drug delivery may provide a more efficient and less dangerous approach to overcome the limits of traditional chemotherapy. Including the creation of nanoscale delivery vehicles capable of directing the release of chemotherapeutic drugs into cancer cells only. This study aims to investigate p14 peptide that would specifically target colorectal cancer cells and not normal body cells to develop a targeted drug delivery system using gold nanoparticles. This study serves as a pilot study of the primary aim. To achieve this, the effect of the peptide p14 and peptide functionalized gold nanoparticles (p14-AuNP) on colon cancer cells (HT-29) and normal epithelial cells (KMST-6) was determined. Firstly, gold nanoparticles were chemically synthesised and then functionalized with p14 peptide through Polyethylene glycol. Then assessment of their effect through in vitro cytotoxicity assay (MTT) and gene expression analysis (RT-qPCR) was conducted. Nanoparticles’ synthesis and functionalization was performed and confirmed: In vitro cytotoxicity through MTT assay was successfully conducted and p14-AuNP showed toxicity against colon cancer cells and lesser toxicity towards normal cells as compared to 5-Flourouracil (commercially approved drug for colon cancer treatment). Gene expression analysis revealed that apoptosis was induced in both cell lines by p14-AuNP either through upregulation of caspase 3, 7 and/or BCL2. A cell survival gene, AKT1, also had significant effect on this. CDC42 was downregulated which indicates that cell proliferation was inhibited. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Investigating the interannual variability of the Benguela coastal upwelling system using a ROMS numerical model from 1993-2014
- Silima, Rudzani Faith, Roagosha, Moagabo
- Authors: Silima, Rudzani Faith , Roagosha, Moagabo
- Date: 2023-12
- Subjects: Oceanography , Coasts , Marine sciences
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62586 , vital:72826
- Description: The seasonal and interannual variability of the coastal Benguela upwelling system is described using 22 years (September 1993 - December 2014) of a regional Ocean model (ROMS) output. The model-derived SSTs are evaluated against satellite SSTs (GHRSST) and biases between the datasets investigated, allowing for confidence in using the ROMS data to investigate details of spatial and temporal variability over the Benguela System. Variability of coastal SSTs are investigated together with alongshore winds (from the ERA-Interim Reanalysis product). The driver of the seasonality in upwelling in the Benguela region is the seasonal shift of the South Atlantic High pressure system, leading to an enhanced seasonal signal in the southern Benguela (with strongest upwelling favourable winds in austral spring and summer). In the northern Benguela, the seasonal signal reduces with the peak of upwelling favourable winds shifting to late winter and spring. Interannual variability is evident in the model and is investigated with respect to various modes of climate variability. Though the direct relationship of the Benguela upwelling system to large-scale climate modes such as SAM and ENSO is not clear in most places, some evidence was found for their connection. For instance, in the southernmost cell of the southern Benguela a significant positive and negative correlation exists between SST and wind respectively with ENSO during summer months. This relates to increased (decreased) winds and decreased (increased) SST during La Niña (El Niño) events. Although there was no direct correlation with either SST or alongshore wind anywhere in the Benguela system, there was some indication of its importance. A trend toward a positive SAM (i.e a more poleward position of the South Atlantic High-Pressure system) was consistent with a trend toward enhanced winds and reduced SSTs in the southernmost upwelling cell. In addition to this, there was evidence to suggest that when SAM and ENSO are out-of-phase, which occurred primarily during summer months, the wind and SST response is amplified. This seemed to be particularly true in the first 10 years of the timeseries when the anomalies were strongly alternating. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Silima, Rudzani Faith , Roagosha, Moagabo
- Date: 2023-12
- Subjects: Oceanography , Coasts , Marine sciences
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62586 , vital:72826
- Description: The seasonal and interannual variability of the coastal Benguela upwelling system is described using 22 years (September 1993 - December 2014) of a regional Ocean model (ROMS) output. The model-derived SSTs are evaluated against satellite SSTs (GHRSST) and biases between the datasets investigated, allowing for confidence in using the ROMS data to investigate details of spatial and temporal variability over the Benguela System. Variability of coastal SSTs are investigated together with alongshore winds (from the ERA-Interim Reanalysis product). The driver of the seasonality in upwelling in the Benguela region is the seasonal shift of the South Atlantic High pressure system, leading to an enhanced seasonal signal in the southern Benguela (with strongest upwelling favourable winds in austral spring and summer). In the northern Benguela, the seasonal signal reduces with the peak of upwelling favourable winds shifting to late winter and spring. Interannual variability is evident in the model and is investigated with respect to various modes of climate variability. Though the direct relationship of the Benguela upwelling system to large-scale climate modes such as SAM and ENSO is not clear in most places, some evidence was found for their connection. For instance, in the southernmost cell of the southern Benguela a significant positive and negative correlation exists between SST and wind respectively with ENSO during summer months. This relates to increased (decreased) winds and decreased (increased) SST during La Niña (El Niño) events. Although there was no direct correlation with either SST or alongshore wind anywhere in the Benguela system, there was some indication of its importance. A trend toward a positive SAM (i.e a more poleward position of the South Atlantic High-Pressure system) was consistent with a trend toward enhanced winds and reduced SSTs in the southernmost upwelling cell. In addition to this, there was evidence to suggest that when SAM and ENSO are out-of-phase, which occurred primarily during summer months, the wind and SST response is amplified. This seemed to be particularly true in the first 10 years of the timeseries when the anomalies were strongly alternating. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Mechanical recyclability and biodegradation of biopolymers, biopolymer blends and biocomposite in natural environmental conditions
- Authors: Nomadolo, Nomvuyo Elizabeth
- Date: 2023-12
- Subjects: Polymers , Polymeric composites , Biopolymers
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62539 , vital:72822
- Description: The present research aimed at investigating mechanical recyclability and studying the potential biotic and abiotic degradation behaviors of biobased biodegradable polymers in different environmental conditions. The mechanical recyclability tests monitored the effect of multiple reprocessing on the mechanical, thermal, physical, chemical, and morphological properties of poly (butylene adipate-co-terephthalate) (PBAT), poly (butylene succinate) (PBS), poly (lactic acid) (PLA), PBAT-PBS blend, and PBAT-thermoplastic starch (TPS) composite. Low-density polyethylene (LDPE), a conventional non-biodegradable plastic, was also monitored for comparison studies. The mechanical recyclability tests were carried out by eight melt extrusion cycles using twin-screw extrusion and injection molding processing techniques. Tensile testing, impact analysis, melt flow index test (MFI), differential scanning calorimetry (DSC), thermogravimetry (TGA), dynamic mechanical analysis (DMA), Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques were employed to monitor the effect mechanical recycling at each melt extrusion cycle. Tensile and impact strength results showed that PBAT and PBAT-TPS biocomposite were mechanical recyclable for at least eight cycles and this was comparable to LDPE recyclability performance. In contrast, neat PBS, PLA, and PBAT-PBS blend were found to be melt extrudable only up to six cycles as the mechanical properties declined with the increase of reprocessing cycles. MFI tests suggest that molecular weight of PBAT and PBAT-TPS were not significantly affected by multiple extrusion cycles while the melt flow properties of PBS, PLA, and PBAT-PBS samples were affected from third cycle. DSC, TGA, and DMA demonstrated that PBAT and PBAT-TPS were more thermo-mechanically stable than PBS, PLA, and PBAT-PBS blend. FTIR spectroscopy results showed that the chemical structure of both PBAT and PBAT-TPS were unaffected by the multiple recycling cycles typically indicated by characteristic peak vibrations bands of C=O and C-O around 1710 cm-1 and 1046-1100 cm-1, respectively. SEM micrographs of PBS, PLA, and PBAT-PBS clearly evidenced the degradation of the biopolymers by severely fractured morphology as a result multiple reprocessing cycle.The rate of aerobic biodegradation for PBAT-PBS and PBAT-PLA blends was examined under controlled home and industrial composting using the CO2 evolution respirometric method. FTIR, DSC, TGA, X-ray diffraction analysis (XRD), and SEM were employed to monitor the changes in the structural, chemical, thermal, and morphological characteristics of the biopolymer blends before and after biodegradation. The biodegradation tests showed that PBAT-PBS and PBAT-PLA blends exhibited higher degradation rates under industrial composting conditions than under home composting conditions. The increased intensity of hydroxyl and carbonyl absorption bands on the FTIR spectra confirmed that the biodegradation process occurred. SEM revealed that there was microbial colony formation and disintegration on the surfaces of the biopolymer blends. Moreover, abiotic degradation results suggested that thermal and hydrolytic conditions influence the degradation process than sunlight exposure. Additionally, aquatic biodegradation results showed that PBAT-PBS blend and PBAT-TPS composite undergo a higher rate of biodegradation as compared to PBAT, PBS, and PLA.The results obtained from this research work conclude that biobased biodegradable polymers can be mechanically recycled, and they are suitable for biological degradation in industrial composting, home composting and marine environment. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Nomadolo, Nomvuyo Elizabeth
- Date: 2023-12
- Subjects: Polymers , Polymeric composites , Biopolymers
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62539 , vital:72822
- Description: The present research aimed at investigating mechanical recyclability and studying the potential biotic and abiotic degradation behaviors of biobased biodegradable polymers in different environmental conditions. The mechanical recyclability tests monitored the effect of multiple reprocessing on the mechanical, thermal, physical, chemical, and morphological properties of poly (butylene adipate-co-terephthalate) (PBAT), poly (butylene succinate) (PBS), poly (lactic acid) (PLA), PBAT-PBS blend, and PBAT-thermoplastic starch (TPS) composite. Low-density polyethylene (LDPE), a conventional non-biodegradable plastic, was also monitored for comparison studies. The mechanical recyclability tests were carried out by eight melt extrusion cycles using twin-screw extrusion and injection molding processing techniques. Tensile testing, impact analysis, melt flow index test (MFI), differential scanning calorimetry (DSC), thermogravimetry (TGA), dynamic mechanical analysis (DMA), Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques were employed to monitor the effect mechanical recycling at each melt extrusion cycle. Tensile and impact strength results showed that PBAT and PBAT-TPS biocomposite were mechanical recyclable for at least eight cycles and this was comparable to LDPE recyclability performance. In contrast, neat PBS, PLA, and PBAT-PBS blend were found to be melt extrudable only up to six cycles as the mechanical properties declined with the increase of reprocessing cycles. MFI tests suggest that molecular weight of PBAT and PBAT-TPS were not significantly affected by multiple extrusion cycles while the melt flow properties of PBS, PLA, and PBAT-PBS samples were affected from third cycle. DSC, TGA, and DMA demonstrated that PBAT and PBAT-TPS were more thermo-mechanically stable than PBS, PLA, and PBAT-PBS blend. FTIR spectroscopy results showed that the chemical structure of both PBAT and PBAT-TPS were unaffected by the multiple recycling cycles typically indicated by characteristic peak vibrations bands of C=O and C-O around 1710 cm-1 and 1046-1100 cm-1, respectively. SEM micrographs of PBS, PLA, and PBAT-PBS clearly evidenced the degradation of the biopolymers by severely fractured morphology as a result multiple reprocessing cycle.The rate of aerobic biodegradation for PBAT-PBS and PBAT-PLA blends was examined under controlled home and industrial composting using the CO2 evolution respirometric method. FTIR, DSC, TGA, X-ray diffraction analysis (XRD), and SEM were employed to monitor the changes in the structural, chemical, thermal, and morphological characteristics of the biopolymer blends before and after biodegradation. The biodegradation tests showed that PBAT-PBS and PBAT-PLA blends exhibited higher degradation rates under industrial composting conditions than under home composting conditions. The increased intensity of hydroxyl and carbonyl absorption bands on the FTIR spectra confirmed that the biodegradation process occurred. SEM revealed that there was microbial colony formation and disintegration on the surfaces of the biopolymer blends. Moreover, abiotic degradation results suggested that thermal and hydrolytic conditions influence the degradation process than sunlight exposure. Additionally, aquatic biodegradation results showed that PBAT-PBS blend and PBAT-TPS composite undergo a higher rate of biodegradation as compared to PBAT, PBS, and PLA.The results obtained from this research work conclude that biobased biodegradable polymers can be mechanically recycled, and they are suitable for biological degradation in industrial composting, home composting and marine environment. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Statistical analysis of hydrogeochemical data from fractured rock aquifers around Beaufort West, South Africa
- Authors: Berkland, James
- Date: 2023-12
- Subjects: Groundwater -- South Africa -- Beaufort West , Hydrogeology -- South Africa -- Beaufort West , Aquifers -- South Africa -- Beaufort West
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62442 , vital:72736
- Description: Knowledge surrounding the procedures and protocols related to groundwater sampling are currently limited. In particular, the sampling of radioactive elements from fractured rock aquifers is poorly understood and in need of further research. The aim of this study is to provide a comparative insight into groundwater sampling methods used for the sampling of major and minor elements as well as trace elements within fractured rock aquifers in the immediate vicinity of Beaufort West. The influence of sampling source, seasonality, and vertical flows on sample results are observed. Furthermore, the importance of historical datasets is raised. Aims of this study were achieved by making use of historical data from numerous studies that were conducted near the Karoo town of Beaufort West. Potential profitable uranium deposits saw a great influx of research into the geology, topography, climate and hydrogeology. Synthesising data from these historical research papers has provided valuable information regarding the influences of sampling procedures on the results. A total of 695 well data samples were analysed from four studies collected from farms around Beaufort West. The importance of adequately purging a well prior to sampling cannot be stressed enough. There are minimal chemical differences between sampling boreholes and wind pumps, however there was a noticeable difference in the inter-relationships between major chemical elements. Groundwater samplers were found to be contaminated with Zinc and Copper attributed to wind pump fittings. Boreholes were also analysed to observe any changes in depth. Sodium, temperature and uranium had little to no changes with depth due to the homogenous nature of the borehole water. Principal component analysis was conducted on 159 groundwater samples comprised of 13 variables. These samples were reduced to four principal components (PC) which explained a total of 91.09% of the total variance. Factor one explained 61.99% of the total variance and was strongly associated with water-type and lithology while factor two (13.57%) shows the potential relationship between molybdenum and uranium as well as possible copper contamination as a result of wind pump and borehole fittings. Further research should be conducted by carrying out multiple sampling procedures on a selection of controlled wells to determine the best applicable sampling procedures. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Berkland, James
- Date: 2023-12
- Subjects: Groundwater -- South Africa -- Beaufort West , Hydrogeology -- South Africa -- Beaufort West , Aquifers -- South Africa -- Beaufort West
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62442 , vital:72736
- Description: Knowledge surrounding the procedures and protocols related to groundwater sampling are currently limited. In particular, the sampling of radioactive elements from fractured rock aquifers is poorly understood and in need of further research. The aim of this study is to provide a comparative insight into groundwater sampling methods used for the sampling of major and minor elements as well as trace elements within fractured rock aquifers in the immediate vicinity of Beaufort West. The influence of sampling source, seasonality, and vertical flows on sample results are observed. Furthermore, the importance of historical datasets is raised. Aims of this study were achieved by making use of historical data from numerous studies that were conducted near the Karoo town of Beaufort West. Potential profitable uranium deposits saw a great influx of research into the geology, topography, climate and hydrogeology. Synthesising data from these historical research papers has provided valuable information regarding the influences of sampling procedures on the results. A total of 695 well data samples were analysed from four studies collected from farms around Beaufort West. The importance of adequately purging a well prior to sampling cannot be stressed enough. There are minimal chemical differences between sampling boreholes and wind pumps, however there was a noticeable difference in the inter-relationships between major chemical elements. Groundwater samplers were found to be contaminated with Zinc and Copper attributed to wind pump fittings. Boreholes were also analysed to observe any changes in depth. Sodium, temperature and uranium had little to no changes with depth due to the homogenous nature of the borehole water. Principal component analysis was conducted on 159 groundwater samples comprised of 13 variables. These samples were reduced to four principal components (PC) which explained a total of 91.09% of the total variance. Factor one explained 61.99% of the total variance and was strongly associated with water-type and lithology while factor two (13.57%) shows the potential relationship between molybdenum and uranium as well as possible copper contamination as a result of wind pump and borehole fittings. Further research should be conducted by carrying out multiple sampling procedures on a selection of controlled wells to determine the best applicable sampling procedures. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Medication adherence: a review of policy and education in South Africa
- Authors: Nyoni, Cynthia Nomagugu
- Date: 2023-10-31
- Subjects: Patient compliance South Africa , Drugs Administration Study and teaching (Higher) , Pharmacist and patient South Africa , Pharmaceutical policy South Africa , Patient education South Africa , Medication adherence
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419548 , vital:71653
- Description: Medication adherence is a patient's active and voluntary participation in following all the recommendations and instructions agreed upon with a health care provider such as a pharmacist. Adherence is a multidimensional phenomenon determined by the interplay of five factors: patient-related factors, socioeconomic factors, condition-related factors, health system-related factors, and therapy-related factors. Medication non-adherence is a problem in many countries, especially low to middle-income countries, including South Africa (SA). In low to middle-income countries, non-adherence is often worse due to insufficient health resources and inequities in access to health care. Medication adherence is a global problem and has raised the need for research and review. Many healthcare professionals, especially pharmacists, have an essential role in promoting medication adherence. This study described, explained and evaluated the policies in SA relating to the pharmacist's role in promoting medication adherence. Furthermore, it described medication adherence-related education at four universities in South Africa. The study was qualitative, and a two-phased approach was employed. In the first phase, a document analysis of the pharmacist’s role in supporting medication adherence was conducted as described in national policies and guidelines in SA. A total of 38 documents were analysed, including critical documents such as the South African Pharmacy Council Good Pharmacy Practice Manual and Associated SAPC rules (GPP) manual, National Drug Policy (NDP), Standard treatment guidelines (STGS) and Integrated Adherence Guidelines. The READ approach was used in conducting the document analysis and involved (1) preparing materials, (2) extracting data, (3) analysing data, and (4) distilling findings. The critical roles of pharmacists in medication adherence that were identified were in drug use, supply and management, dispensing, therapeutic drug monitoring, pharmacovigilance, pharmaceutical care, and special programmes like antimicrobial stewardship (AMS), multi-drug resistant tuberculosis (MDR-TB) care and antiretroviral treatment (ARV) and chronic conditions. In the second phase, in-depth interviews were conducted with lecturers to investigate and report on the inclusion of medication adherence and the teaching thereof in the curriculum of the Bachelor of Pharmacy Degree (BPharm) in pharmacy institutions in SA. Purposive sampling was used, and seven lecturers from four different institutions participated in the interviews. The interviews were conducted via Zoom® and were transcribed and analysed using thematic analysis. The teaching of medication adherence in the BPharm curriculum of the respective interviewed pharmacy institutions was explored. It was found that the topic of medication adherence was integrated into all subjects throughout the curriculum and not taught as a formal course. Although medication adherence is taught in many disciplines, it is predominantly in pharmacy practice in all institutions. The teaching methods identified included lectures, case studies, workshops, tutorials, practicals, readings, tasks, assignments and videos. The perceived effectiveness of the teaching methods was explored; also the time spent teaching medication adherence and the time efficiency. Student understanding, interest and engagement with the topic were explored and determined through their assessment performance and class attendance. In conclusion, from policies, the pharmacist's role concerning adherence is indirectly integrated into many other roles. It is often not distinguishable from that of other healthcare professionals and is often implied as part of a more generic role. Pharmacy students are educated on medication adherence and the skills and knowledge required to identify, monitor and support patient adherence to therapy. However, there is scope to increase the course content on medication adherence. There is a need to identify effective strategies for preparing pharmacists to assist patients in medication adherence. , Thesis (MPharm) -- Faculty of Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-31
- Authors: Nyoni, Cynthia Nomagugu
- Date: 2023-10-31
- Subjects: Patient compliance South Africa , Drugs Administration Study and teaching (Higher) , Pharmacist and patient South Africa , Pharmaceutical policy South Africa , Patient education South Africa , Medication adherence
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419548 , vital:71653
- Description: Medication adherence is a patient's active and voluntary participation in following all the recommendations and instructions agreed upon with a health care provider such as a pharmacist. Adherence is a multidimensional phenomenon determined by the interplay of five factors: patient-related factors, socioeconomic factors, condition-related factors, health system-related factors, and therapy-related factors. Medication non-adherence is a problem in many countries, especially low to middle-income countries, including South Africa (SA). In low to middle-income countries, non-adherence is often worse due to insufficient health resources and inequities in access to health care. Medication adherence is a global problem and has raised the need for research and review. Many healthcare professionals, especially pharmacists, have an essential role in promoting medication adherence. This study described, explained and evaluated the policies in SA relating to the pharmacist's role in promoting medication adherence. Furthermore, it described medication adherence-related education at four universities in South Africa. The study was qualitative, and a two-phased approach was employed. In the first phase, a document analysis of the pharmacist’s role in supporting medication adherence was conducted as described in national policies and guidelines in SA. A total of 38 documents were analysed, including critical documents such as the South African Pharmacy Council Good Pharmacy Practice Manual and Associated SAPC rules (GPP) manual, National Drug Policy (NDP), Standard treatment guidelines (STGS) and Integrated Adherence Guidelines. The READ approach was used in conducting the document analysis and involved (1) preparing materials, (2) extracting data, (3) analysing data, and (4) distilling findings. The critical roles of pharmacists in medication adherence that were identified were in drug use, supply and management, dispensing, therapeutic drug monitoring, pharmacovigilance, pharmaceutical care, and special programmes like antimicrobial stewardship (AMS), multi-drug resistant tuberculosis (MDR-TB) care and antiretroviral treatment (ARV) and chronic conditions. In the second phase, in-depth interviews were conducted with lecturers to investigate and report on the inclusion of medication adherence and the teaching thereof in the curriculum of the Bachelor of Pharmacy Degree (BPharm) in pharmacy institutions in SA. Purposive sampling was used, and seven lecturers from four different institutions participated in the interviews. The interviews were conducted via Zoom® and were transcribed and analysed using thematic analysis. The teaching of medication adherence in the BPharm curriculum of the respective interviewed pharmacy institutions was explored. It was found that the topic of medication adherence was integrated into all subjects throughout the curriculum and not taught as a formal course. Although medication adherence is taught in many disciplines, it is predominantly in pharmacy practice in all institutions. The teaching methods identified included lectures, case studies, workshops, tutorials, practicals, readings, tasks, assignments and videos. The perceived effectiveness of the teaching methods was explored; also the time spent teaching medication adherence and the time efficiency. Student understanding, interest and engagement with the topic were explored and determined through their assessment performance and class attendance. In conclusion, from policies, the pharmacist's role concerning adherence is indirectly integrated into many other roles. It is often not distinguishable from that of other healthcare professionals and is often implied as part of a more generic role. Pharmacy students are educated on medication adherence and the skills and knowledge required to identify, monitor and support patient adherence to therapy. However, there is scope to increase the course content on medication adherence. There is a need to identify effective strategies for preparing pharmacists to assist patients in medication adherence. , Thesis (MPharm) -- Faculty of Pharmacy, 2023
- Full Text:
- Date Issued: 2023-10-31
A case study of role conflict experienced by middle management during organizational change
- Authors: Sepeng, Mugabe
- Date: 2023-10-13
- Subjects: Role conflict , Change management , Middle managers , Middle management , ISO 9001 Standard Implementation of
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419189 , vital:71624
- Description: This research investigation is based on continuous improvement changes arising from - and related to - ISO 9001 implementation at Sundays River Citrus Company (SRCC), which is one of the biggest packers, marketers, and exporters of citrus fruit in South Africa. The Board of SRCC adopted ISO 9001 to ensure organizational efficiency and sustainability while improving quality control, customer service, teamwork and leadership. However, research indicates not all organizations that have Implemented ISO 9001 realize the intended benefits. While no research was available on the citrus agriculture industry, research in the tourism industry indicates that not only did some companies not realize the expected benefits, but also incurred substantial investment costs. It is estimated that approximately thirty to ninety percent of change initiatives fail to meet their objectives, and research studies also indicate that middle managers play a critical role that can influence the outcomes of a change project. However, Balogun (2003) indicates that middle managers play a complex role and are exposed to role conflict, which can influence the outcomes of change initiatives. In this context, this research study aimed to investigate the role conflicts experienced by middle managers during the process of an ISO 9001 continuous improvement change. The study draws on role theory, applying it to their management of change. The following role conflict types were investigated: (1) intra-sender conflict, (2) inter-sender role conflict, (3) inter-role conflict, (4) role ambiguity and (5) role strain. The research approach is qualitative, and has adopted a post-positivist paradigm, utilizing a deductive qualitative method. The study adopted a case study approach. Data was gathered mainly from interviews and supported by organizational documents. Semi structured interviews were conducted with questions formulated through the use of the coding manual (See Appendix C) to ensure alignment of data collection with the research propositions derived from literature. A deductive thematic analysis method was used to analyze the interview data. The research findings confirmed that during continuous improvement change, as middle managers strived to satisfy the incompatible expectations of role senders (mainly senior and junior managers), they experienced the five role conflict types. The study findings also indicate that middle managers experience conflicts due to the incompatible expectations of other role senders such as quality and marketing departments. The findings suggest that middle managers are managing these conflicts, but notes that they do require some assistance and support from senior management. The study concludes with managerial and research recommendations. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Sepeng, Mugabe
- Date: 2023-10-13
- Subjects: Role conflict , Change management , Middle managers , Middle management , ISO 9001 Standard Implementation of
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419189 , vital:71624
- Description: This research investigation is based on continuous improvement changes arising from - and related to - ISO 9001 implementation at Sundays River Citrus Company (SRCC), which is one of the biggest packers, marketers, and exporters of citrus fruit in South Africa. The Board of SRCC adopted ISO 9001 to ensure organizational efficiency and sustainability while improving quality control, customer service, teamwork and leadership. However, research indicates not all organizations that have Implemented ISO 9001 realize the intended benefits. While no research was available on the citrus agriculture industry, research in the tourism industry indicates that not only did some companies not realize the expected benefits, but also incurred substantial investment costs. It is estimated that approximately thirty to ninety percent of change initiatives fail to meet their objectives, and research studies also indicate that middle managers play a critical role that can influence the outcomes of a change project. However, Balogun (2003) indicates that middle managers play a complex role and are exposed to role conflict, which can influence the outcomes of change initiatives. In this context, this research study aimed to investigate the role conflicts experienced by middle managers during the process of an ISO 9001 continuous improvement change. The study draws on role theory, applying it to their management of change. The following role conflict types were investigated: (1) intra-sender conflict, (2) inter-sender role conflict, (3) inter-role conflict, (4) role ambiguity and (5) role strain. The research approach is qualitative, and has adopted a post-positivist paradigm, utilizing a deductive qualitative method. The study adopted a case study approach. Data was gathered mainly from interviews and supported by organizational documents. Semi structured interviews were conducted with questions formulated through the use of the coding manual (See Appendix C) to ensure alignment of data collection with the research propositions derived from literature. A deductive thematic analysis method was used to analyze the interview data. The research findings confirmed that during continuous improvement change, as middle managers strived to satisfy the incompatible expectations of role senders (mainly senior and junior managers), they experienced the five role conflict types. The study findings also indicate that middle managers experience conflicts due to the incompatible expectations of other role senders such as quality and marketing departments. The findings suggest that middle managers are managing these conflicts, but notes that they do require some assistance and support from senior management. The study concludes with managerial and research recommendations. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2023
- Full Text:
- Date Issued: 2023-10-13
A distributed approach to leadership in an academic department in a South African university: an exploratory case study
- Authors: Haufiku, Kenneth David
- Date: 2023-10-13
- Subjects: Universities and colleges Administration , Education, Higher South Africa , Distributed leadership , College department heads South Africa , School management and organization South Africa , Group decision making
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419748 , vital:71672
- Description: The Head of Department (HOD) position at a university has traditionally been viewed as an individual construct. However, due to the demanding nature of such a position, it is not sought-after, as it remains exclusive and unappealing to many academics. Moreover, it is a position that does not encourage inclusive leadership. Tension and role ambiguity are known to arise between the scholarly project on the one hand and management and administrative matters on the other. To address challenges associated with this singular leadership position, an academic department at a South African university adopted a distributed leadership approach in their department as a research experiment. My study was based on this research experiment. I designed this research as an exploratory case study, guided by a socio-cultural conceptualisation of distributed leadership that included a leader-plus and a practice aspect, defined as a product of the interactions of school leaders, followers and their situation. This qualitative case study aimed to describe and explain how a distributed leadership approach was understood and practised in an academic department. It also investigated the enablements and constraints of the approach. Data were generated through document analysis, observation, and individual and focus group interviews. The participants in this study included the departmental leadership team and the department’s academic and administrative staff. Unfortunately, my study took place during the global COVID-19 pandemic and national lockdowns. I had no choice but to adapt my data generation methods due to lockdown restrictions. As a result, most data generation was done via online communication. The study used inductive and abductive analysis to make the data meaningful to the reader. The findings revealed that different participants had different ideas about distributed leadership. Distributed leadership was understood as a socio-cultural practice rather than an individual practice with multiple leaders in relational practice. In addition, this approach was understood as a way of developing and sharing expertise by encouraging teamwork, collegiality and collective decision-making which aligns with the notion of democratic decision-making which creates a platform for the enablement of leadership in others. The study further explored how distributed leadership was practised. The findings were that the HOD position, usually a one-person role, was reconceptualised as a HOD team comprised of three academics and the departmental administrator. The HOD team divided the work among themselves, and this was done according to each individual’s expertise. In addition, leadership within the academic department was not limited to the HOD team but stretched across the department; thus, multiple leaders were evident. Therefore, based on the data, this study discovered that a distributed approach values leadership expertise in others. Consequently, it can be used to promote an inclusive environment in which any organisation member can lead. Inclusivity in the decision-making process was also regarded as a strong practice in the academic department. As a result, this study contends that those in formal positions can develop leadership in others through a distributed leadership approach. Through that, lecturer leadership was enacted through formal faculty and university structures and informally as and when the situation required it. The enablements of this departmental leadership approach included the structural innovation of the Friday check-in as well as the buddy system. These two innovations provided the space for collegiality and the development of voice and leadership. The consultative nature of the HOD team was also viewed as an enablement. Certain factors constrained the distributed leadership approach, one of which was the tension between the hierarchical structure of the university and the more horizontal, distributed leadership approach being piloted in the academic department. In addition to that, another constraint was also very real with the transition to Zoom as an online teaching, learning and supervision platform as a consequence of the COVID-19 pandemic. The final constraint was experienced concerning the department’s history, as it was within a historically White university in South Africa. The effects of this history impacted the departmental culture and, as we know from the literature, institutional culture is extremely difficult to change. Finally, the study concluded that conceptualising distributed leadership as a sociocultural practice with leader-plus and practice aspects provides descriptive language and a solid theoretical and analytical framework for a distributed leadership study. The study makes an important knowledge contribution in the African Higher Education context as limited research has been carried out in this area. Furthermore, in terms of practice, my study serves as a stimulus for leadership discussions that are beneficial to everyone involved in educational institutions as they promote a level of leadership reflexivity, currently absent in many institutions. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Haufiku, Kenneth David
- Date: 2023-10-13
- Subjects: Universities and colleges Administration , Education, Higher South Africa , Distributed leadership , College department heads South Africa , School management and organization South Africa , Group decision making
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419748 , vital:71672
- Description: The Head of Department (HOD) position at a university has traditionally been viewed as an individual construct. However, due to the demanding nature of such a position, it is not sought-after, as it remains exclusive and unappealing to many academics. Moreover, it is a position that does not encourage inclusive leadership. Tension and role ambiguity are known to arise between the scholarly project on the one hand and management and administrative matters on the other. To address challenges associated with this singular leadership position, an academic department at a South African university adopted a distributed leadership approach in their department as a research experiment. My study was based on this research experiment. I designed this research as an exploratory case study, guided by a socio-cultural conceptualisation of distributed leadership that included a leader-plus and a practice aspect, defined as a product of the interactions of school leaders, followers and their situation. This qualitative case study aimed to describe and explain how a distributed leadership approach was understood and practised in an academic department. It also investigated the enablements and constraints of the approach. Data were generated through document analysis, observation, and individual and focus group interviews. The participants in this study included the departmental leadership team and the department’s academic and administrative staff. Unfortunately, my study took place during the global COVID-19 pandemic and national lockdowns. I had no choice but to adapt my data generation methods due to lockdown restrictions. As a result, most data generation was done via online communication. The study used inductive and abductive analysis to make the data meaningful to the reader. The findings revealed that different participants had different ideas about distributed leadership. Distributed leadership was understood as a socio-cultural practice rather than an individual practice with multiple leaders in relational practice. In addition, this approach was understood as a way of developing and sharing expertise by encouraging teamwork, collegiality and collective decision-making which aligns with the notion of democratic decision-making which creates a platform for the enablement of leadership in others. The study further explored how distributed leadership was practised. The findings were that the HOD position, usually a one-person role, was reconceptualised as a HOD team comprised of three academics and the departmental administrator. The HOD team divided the work among themselves, and this was done according to each individual’s expertise. In addition, leadership within the academic department was not limited to the HOD team but stretched across the department; thus, multiple leaders were evident. Therefore, based on the data, this study discovered that a distributed approach values leadership expertise in others. Consequently, it can be used to promote an inclusive environment in which any organisation member can lead. Inclusivity in the decision-making process was also regarded as a strong practice in the academic department. As a result, this study contends that those in formal positions can develop leadership in others through a distributed leadership approach. Through that, lecturer leadership was enacted through formal faculty and university structures and informally as and when the situation required it. The enablements of this departmental leadership approach included the structural innovation of the Friday check-in as well as the buddy system. These two innovations provided the space for collegiality and the development of voice and leadership. The consultative nature of the HOD team was also viewed as an enablement. Certain factors constrained the distributed leadership approach, one of which was the tension between the hierarchical structure of the university and the more horizontal, distributed leadership approach being piloted in the academic department. In addition to that, another constraint was also very real with the transition to Zoom as an online teaching, learning and supervision platform as a consequence of the COVID-19 pandemic. The final constraint was experienced concerning the department’s history, as it was within a historically White university in South Africa. The effects of this history impacted the departmental culture and, as we know from the literature, institutional culture is extremely difficult to change. Finally, the study concluded that conceptualising distributed leadership as a sociocultural practice with leader-plus and practice aspects provides descriptive language and a solid theoretical and analytical framework for a distributed leadership study. The study makes an important knowledge contribution in the African Higher Education context as limited research has been carried out in this area. Furthermore, in terms of practice, my study serves as a stimulus for leadership discussions that are beneficial to everyone involved in educational institutions as they promote a level of leadership reflexivity, currently absent in many institutions. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10-13
A second skin: investigating the role of dress in identity formation
- Featherstone, Juanito Romario
- Authors: Featherstone, Juanito Romario
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425322 , vital:72229
- Description: This thesis is a secondary component to an artistic practice-led process and as such, is guided by my own artistic practice in that way. In this body of work, I use myself as the main character or protagonist for the artworks that I have created. However, both the thesis and the exhibition also respond to social issues of identity beyond the personal and examines the construction of identity in a South African, and more specifically Makhanda context, as that is the larger context in which I am situated. The work itself is inspired by memories and experiences of feeling uncomfortable in my own (first) skin, and how I found that comfort in my second skin (dress). My professional art practice and my thesis are based on the concept of clothes as a second skin for human beings, specifically observing the ways in which we utilise dress to construct and express our identities. As such, this thesis is an attempt at understanding the relationship between clothes and the body through the lens of identity politics. Through the topics and artworks discussed in visual and textual analysis, this thesis intends to unpack the properties of dress as a complex medium individuals can utilise as a tool to construct their identity. This is partially achieved through the exploration of my own personal experiences of dress and of the spaces that shaped and mediated the construction of identity. Lastly, it is an attempt to understand the experiences of dress in parallel to the experience of the body/self, which consists of the world within and the one outside. , Thesis (MFA) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Featherstone, Juanito Romario
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425322 , vital:72229
- Description: This thesis is a secondary component to an artistic practice-led process and as such, is guided by my own artistic practice in that way. In this body of work, I use myself as the main character or protagonist for the artworks that I have created. However, both the thesis and the exhibition also respond to social issues of identity beyond the personal and examines the construction of identity in a South African, and more specifically Makhanda context, as that is the larger context in which I am situated. The work itself is inspired by memories and experiences of feeling uncomfortable in my own (first) skin, and how I found that comfort in my second skin (dress). My professional art practice and my thesis are based on the concept of clothes as a second skin for human beings, specifically observing the ways in which we utilise dress to construct and express our identities. As such, this thesis is an attempt at understanding the relationship between clothes and the body through the lens of identity politics. Through the topics and artworks discussed in visual and textual analysis, this thesis intends to unpack the properties of dress as a complex medium individuals can utilise as a tool to construct their identity. This is partially achieved through the exploration of my own personal experiences of dress and of the spaces that shaped and mediated the construction of identity. Lastly, it is an attempt to understand the experiences of dress in parallel to the experience of the body/self, which consists of the world within and the one outside. , Thesis (MFA) -- Faculty of Humanities, Fine Art, 2023
- Full Text:
- Date Issued: 2023-10-13
A study on visual inspection of citrus sorters in a packhouse in the Eastern Cape of South Africa
- Authors: Maher, Christopher Richard
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424256 , vital:72137
- Description: Background and Purpose. The South African citrus industry is a major global producer of citrus as well as the second largest exporter of citrus fruit in the world. This industry provides employment to an estimated 112 000 workers in South Africa and is vital in providing economic opportunities to communities such as those in the Sunday’s River Valley in the Eastern Cape province of South Africa due to the low employment and education levels within this province. Citrus sorting is a visual inspection task that requires workers to sustain attention and remain vigilant for the duration of a working shift. Their role in the packhouse is to ensure that no defective products are packed for export or the local market and that the fruit meets the customers’ expectations. Since the demands of sorting citrus are poorly understood, this study attempted to assess the effect that sorting citrus has on vigilance performance as well as attempt to quantify perceived workload while taking into account different contextual factors that affect perceptions of this working task. Methods. This study was conducted within a citrus packhouse in the Eastern Cape province of South Africa. The sample was comprised of individuals employed by the packhouse as citrus sorters. In addition to a recruitment and information session, testing was conducted at three intervals during a working shift on four consecutive days. Each time, indicators of vigilance, such as correct responses, sensitivity, reaction time, false alarms and misses, were collected during a 5-minute computerised version of the Mackworth Clock-test, while perceived workload was assessed with the NASA-TLX scale, and sleepiness was recording using the WITS Sleepiness Scale. Furthermore, an open-ended question was asked to further understand factors affecting the ability of participants to concentrate during their task of sorting. Results. 18 participants consented to participate in this study. 16 of these individuals identified as female with an average age of 30 years (± 7). 83% of participants were of Black African descent and were isiXhosa speakers, while 17% of participants were of Coloured descent and Afrikaans speakers. This study found that performance, as measured by the percentage of correct responses, sensitivity and reaction time on the 5-minute long Mackworth Clock Test was not significantly affected as time-on-task for sorting citrus increased during a working shift, neither did performance on the vigilance test change as days of the week proceeded. However, ‘misses’ during the vigilance test were found to significantly decrease over the course of a working shift, thus contradicting the expected outcomes of this study. Perceived workload of sorting citrus, as well as perceived sleepiness, significantly increased with time-on-task during the course of a working shift. The major contributions for this increase in perceived workload while sorting citrus were derived from the Mental Demand and Physical Demand sub-scale for the NASA-TLX. However, responses from the open-ended question indicated that participants generally enjoyed their work, although there were factors, such as the nature of fruit and social set-up of work, that negatively affected this perception. Discussion. The results from this study contradicted the researcher’s expectations. It was anticipated that measures of correct responses and sensitivity would decrease and misses, and reaction time would increase with time-on-task for sorting citrus, yet vigilance indicators from the Mackworth Clock Test generally indicated no change in vigilance, and, according to “misses” even improved with time-on-task. A likely explanation for this is that the use of a 5-minute Mackworth Clock-test was unsuitable in this context, or rather, the time of this test was not long enough to induce a ‘vigilance decrement’. Furthermore, in order to administer this vigilance test, participants were taken off the production line and led to a testing room which most likely increased their levels of arousal, thus affecting performance on the vigilance test. However, even though perceived sleepiness was found to significantly increase over the course of a working shift, these data correlated poorly with the vigilance results, thus contradicting the expected outcomes of the study. Mental demand significantly increased, possibly due to the demand of attentional informational processing required for sorting, as well as various environmental factors present within the packhouse. Physical demand, too, significantly increased as workers were required to remain standing throughout their working task as well as to make use of their upper extremities to remove defective fruit. Correlation analyses showed significantly weak correlation for Mackworth Clock Test variables and sleepiness ratings to all other variables. NASA-TLX variables, however, generally showed significantly moderate correlations with one another. Conclusion. It remains unclear how vigilance changes and sustained attention while sorting citrus, since the experiment did not show changes in performance. This is largely attributed to the methodological set-up which could have increased arousal and therefore affected vigilance. It is recommended that future studies research vigilance and sustained attention during the sorting itself, rather than attempting to infer vigilance results from a computerised vigilance test. Perceived workload of sorting, however, increased over the course of a working shift due to significant increases in perceptions of the physical and mental demands of sorting. Future studies should address concerns relating to the physical demand of sorting. Furthermore, it would be beneficial to compare responses of day and night shift sorters to further understand how the relationship between these variables may change. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Maher, Christopher Richard
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424256 , vital:72137
- Description: Background and Purpose. The South African citrus industry is a major global producer of citrus as well as the second largest exporter of citrus fruit in the world. This industry provides employment to an estimated 112 000 workers in South Africa and is vital in providing economic opportunities to communities such as those in the Sunday’s River Valley in the Eastern Cape province of South Africa due to the low employment and education levels within this province. Citrus sorting is a visual inspection task that requires workers to sustain attention and remain vigilant for the duration of a working shift. Their role in the packhouse is to ensure that no defective products are packed for export or the local market and that the fruit meets the customers’ expectations. Since the demands of sorting citrus are poorly understood, this study attempted to assess the effect that sorting citrus has on vigilance performance as well as attempt to quantify perceived workload while taking into account different contextual factors that affect perceptions of this working task. Methods. This study was conducted within a citrus packhouse in the Eastern Cape province of South Africa. The sample was comprised of individuals employed by the packhouse as citrus sorters. In addition to a recruitment and information session, testing was conducted at three intervals during a working shift on four consecutive days. Each time, indicators of vigilance, such as correct responses, sensitivity, reaction time, false alarms and misses, were collected during a 5-minute computerised version of the Mackworth Clock-test, while perceived workload was assessed with the NASA-TLX scale, and sleepiness was recording using the WITS Sleepiness Scale. Furthermore, an open-ended question was asked to further understand factors affecting the ability of participants to concentrate during their task of sorting. Results. 18 participants consented to participate in this study. 16 of these individuals identified as female with an average age of 30 years (± 7). 83% of participants were of Black African descent and were isiXhosa speakers, while 17% of participants were of Coloured descent and Afrikaans speakers. This study found that performance, as measured by the percentage of correct responses, sensitivity and reaction time on the 5-minute long Mackworth Clock Test was not significantly affected as time-on-task for sorting citrus increased during a working shift, neither did performance on the vigilance test change as days of the week proceeded. However, ‘misses’ during the vigilance test were found to significantly decrease over the course of a working shift, thus contradicting the expected outcomes of this study. Perceived workload of sorting citrus, as well as perceived sleepiness, significantly increased with time-on-task during the course of a working shift. The major contributions for this increase in perceived workload while sorting citrus were derived from the Mental Demand and Physical Demand sub-scale for the NASA-TLX. However, responses from the open-ended question indicated that participants generally enjoyed their work, although there were factors, such as the nature of fruit and social set-up of work, that negatively affected this perception. Discussion. The results from this study contradicted the researcher’s expectations. It was anticipated that measures of correct responses and sensitivity would decrease and misses, and reaction time would increase with time-on-task for sorting citrus, yet vigilance indicators from the Mackworth Clock Test generally indicated no change in vigilance, and, according to “misses” even improved with time-on-task. A likely explanation for this is that the use of a 5-minute Mackworth Clock-test was unsuitable in this context, or rather, the time of this test was not long enough to induce a ‘vigilance decrement’. Furthermore, in order to administer this vigilance test, participants were taken off the production line and led to a testing room which most likely increased their levels of arousal, thus affecting performance on the vigilance test. However, even though perceived sleepiness was found to significantly increase over the course of a working shift, these data correlated poorly with the vigilance results, thus contradicting the expected outcomes of the study. Mental demand significantly increased, possibly due to the demand of attentional informational processing required for sorting, as well as various environmental factors present within the packhouse. Physical demand, too, significantly increased as workers were required to remain standing throughout their working task as well as to make use of their upper extremities to remove defective fruit. Correlation analyses showed significantly weak correlation for Mackworth Clock Test variables and sleepiness ratings to all other variables. NASA-TLX variables, however, generally showed significantly moderate correlations with one another. Conclusion. It remains unclear how vigilance changes and sustained attention while sorting citrus, since the experiment did not show changes in performance. This is largely attributed to the methodological set-up which could have increased arousal and therefore affected vigilance. It is recommended that future studies research vigilance and sustained attention during the sorting itself, rather than attempting to infer vigilance results from a computerised vigilance test. Perceived workload of sorting, however, increased over the course of a working shift due to significant increases in perceptions of the physical and mental demands of sorting. Future studies should address concerns relating to the physical demand of sorting. Furthermore, it would be beneficial to compare responses of day and night shift sorters to further understand how the relationship between these variables may change. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2023
- Full Text:
- Date Issued: 2023-10-13