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 3d printing of brass instruments: a comparative study of French horn mouthpieces
- Authors: Barker, Dylan Bruce
- Date: 2024-04
- Subjects: Horn (Musical instrument) , Three-dimensional printing , Instrumentation and orchestration (Band)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62755 , vital:72939
- Description: The French horn is an orchestral instrument with a rich history that spans centuries, undergoing notable transformations in its design and functionality. A short overview of this history is provided in Appendix A. Originating as a simple coil, the French horn has evolved to encompass a complex valve system, multiple harmonic series, and a diverse range of modifications tailored to players' preferences and requirements. These modifications include mutes, grips, extra keys, and even the exploration of different materials for mouthpieces. The use of plastic rims on mouthpieces, for reasons such as allergies, thermal conductivity, and tactile sensation, has already gained traction among horn players (Tuckwell, 2002). In the realm of manufacturing and technology, the concept of additive manufacturing has emerged as a promising avenue. Referred to as the next "industrial revolution” (Berman, 2012), additive manufacturing has become increasingly accessible through desktop-scale 3D printers. This technology offers a viable method for producing cost-effective musical instruments and enhancers without compromising quality (Kantaros, 2018). As evidenced by a 2018 Roundtable report from the South African Parliament, additive manufacturing aligns with the trajectory of the fourth industrial revolution, prompting governments to develop policies and strategies to harness its potential. Given the significance of additive manufacturing, a comprehensive investigation into applying these new technologies for the horn is warranted. Specifically, material choice, quality of sound, and the experience of performing on a printed mouthpiece is investigated and compared to a traditional metal mouthpiece. While the horn is comprised of many individual components, this study relates specifically to the mouthpiece. A brief appraisal of the significance of the mouthpiece will follow in the next section. , Thesis (MMus) -- Faculty of Humanities, School of Visual and Performing Arts, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Barker, Dylan Bruce
- Date: 2024-04
- Subjects: Horn (Musical instrument) , Three-dimensional printing , Instrumentation and orchestration (Band)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62755 , vital:72939
- Description: The French horn is an orchestral instrument with a rich history that spans centuries, undergoing notable transformations in its design and functionality. A short overview of this history is provided in Appendix A. Originating as a simple coil, the French horn has evolved to encompass a complex valve system, multiple harmonic series, and a diverse range of modifications tailored to players' preferences and requirements. These modifications include mutes, grips, extra keys, and even the exploration of different materials for mouthpieces. The use of plastic rims on mouthpieces, for reasons such as allergies, thermal conductivity, and tactile sensation, has already gained traction among horn players (Tuckwell, 2002). In the realm of manufacturing and technology, the concept of additive manufacturing has emerged as a promising avenue. Referred to as the next "industrial revolution” (Berman, 2012), additive manufacturing has become increasingly accessible through desktop-scale 3D printers. This technology offers a viable method for producing cost-effective musical instruments and enhancers without compromising quality (Kantaros, 2018). As evidenced by a 2018 Roundtable report from the South African Parliament, additive manufacturing aligns with the trajectory of the fourth industrial revolution, prompting governments to develop policies and strategies to harness its potential. Given the significance of additive manufacturing, a comprehensive investigation into applying these new technologies for the horn is warranted. Specifically, material choice, quality of sound, and the experience of performing on a printed mouthpiece is investigated and compared to a traditional metal mouthpiece. While the horn is comprised of many individual components, this study relates specifically to the mouthpiece. A brief appraisal of the significance of the mouthpiece will follow in the next section. , Thesis (MMus) -- Faculty of Humanities, School of Visual and Performing Arts, 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
From Clown Prince to critical phenomenon: Fashioning the Joker as a nomadic war machine
- Authors: Goldmann, Talya
- Date: 2024-04
- Subjects: Joker -- (Fictitious character) , Comic books, strips, etc. -- United States -- History and criticism , Literature and society -- United States
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62769 , vital:72941
- Description: Based on the original clown prince of crime in the DC comic books, the Joker is one of the most notorious villains in cinematic history. He originated in the comic book Batman #1 (Finger, 1940) over eighty years ago, and he remains a prominent character across a myriad of media platforms. In film and television, the Joker has appeared in major and minor roles in approximately nine animated series, eighteen animated films, six live-action series, and five live-action films. Indeed, multiple roles, actors, and decades after the character’s first debut in the Batman television series (1966), the Joker continues to be well-received and sought-after, insofar as every time a new Joker is announced, the character garners more intensive publicity and the film as a whole becomes highly anticipated. Thus, what started as a simple clownish character in the role of a minor villain in Batman (1966), has evolved into a multi-faceted villain so captivating that he has recently earned his own stand-alone films, namely Todd Phillips’ Joker (2019), and the sequel, Joker Folie à Deux (2024) – where he is no longer the antagonist, but now the protagonist. In this research, firstly, key features of the Deleuzoguattarian schema relevant to this study will be presented, before capitalism – as the context of Batman’s Gotham – is considered through a Deleuzoguattarian lens. This study will delve into what makes the beloved Joker so extraordinary along with the aesthetic features associated with his meteoric rise to fame. In this regard, what will be theorized is that the Joker constitutes an example of a Deleuzean nomadic war machine: that is, a critical character who borrows aspects of the State Apparatus and then twists and shapes them into weapons through which he questions and mocks society for its authoritarian and ideological flaws, and with which he exposes its conceptual and ethical blind spots. In this way, he acts like a mirror, reflecting what is wrong with society, and by implication, with the human ‘nature’ – not only in the fictional world of Gotham, but also in the contemporary era created therein. More specifically, discourse analysis and film analysis will be used here, to engage critically with the Joker’s persona in relation to the changing contexts in which the various films were made, in order to trace the development of the character through a Deleuzoguattarian lens. As will be discussed, Phillips’ Joker (2019) signals the deterritorialization of the Joker from the ambit of Batman’s influence, and opens up the possibility for his further deterritorialization as an increasingly mobile and nomadic catalyst of critical thinking beyond even Gotham itself. Then, thirdly, an in-depth analysis on the five key cinematic Jokers will be completed in terms of the characters’ historical contexts, character backgrounds, and aesthetics. And thereafter, the deterritorializing ‘line of flight’ already underway – as by Phillips’ Joker (2019) – will be continued through the creative media production component of this study, which will entail the conceptualization, design and illustration of three new Joker manifestations, each of which will reflect critically upon failing systems in South African society across select time periods, and how these failing systems have contributed to the collective trauma of marginalized groups of people. The first South African Joker manifestation, set in the 1980s, will reflect upon the faltering political infrastructure during the Apartheid era. The second Joker manifestation, set in the early 2000s, will encapsulate the repercussions of the post-Apartheid neoliberal economic landscape. And the third Joker manifestation, set in the 2010s, will draw attention to sociocultural collapse particularly in the space of gender-based violence and sexual assault. Thus, the creation of these Jokers will act as an exploration of trauma, insofar as the tragedy and pain caused by the above-mentioned failing systems will manifest physically through their character designs. In terms of this, and in keeping with the dynamics of appropriation and inflection that are definitive of nomadic war machines, here focus will fall on how their character aesthetics pose critical questions about relevant issues in the South Africa. On account of this, although this research is by definition situated within the spectacle/performance paradigm, it also runs counter to the largely apolitical orientation of creative media production that occurs therein, through its emphasis, instead, on how such creative media production can also entail critical thought that is aimed at thematizing socio-cultural and politico-economic issues and the trauma that they create; thus, this creative media component aims to encourage a more trauma-aware society through art. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2023
- Full Text:
- Date Issued: 2024-04
- Authors: Goldmann, Talya
- Date: 2024-04
- Subjects: Joker -- (Fictitious character) , Comic books, strips, etc. -- United States -- History and criticism , Literature and society -- United States
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62769 , vital:72941
- Description: Based on the original clown prince of crime in the DC comic books, the Joker is one of the most notorious villains in cinematic history. He originated in the comic book Batman #1 (Finger, 1940) over eighty years ago, and he remains a prominent character across a myriad of media platforms. In film and television, the Joker has appeared in major and minor roles in approximately nine animated series, eighteen animated films, six live-action series, and five live-action films. Indeed, multiple roles, actors, and decades after the character’s first debut in the Batman television series (1966), the Joker continues to be well-received and sought-after, insofar as every time a new Joker is announced, the character garners more intensive publicity and the film as a whole becomes highly anticipated. Thus, what started as a simple clownish character in the role of a minor villain in Batman (1966), has evolved into a multi-faceted villain so captivating that he has recently earned his own stand-alone films, namely Todd Phillips’ Joker (2019), and the sequel, Joker Folie à Deux (2024) – where he is no longer the antagonist, but now the protagonist. In this research, firstly, key features of the Deleuzoguattarian schema relevant to this study will be presented, before capitalism – as the context of Batman’s Gotham – is considered through a Deleuzoguattarian lens. This study will delve into what makes the beloved Joker so extraordinary along with the aesthetic features associated with his meteoric rise to fame. In this regard, what will be theorized is that the Joker constitutes an example of a Deleuzean nomadic war machine: that is, a critical character who borrows aspects of the State Apparatus and then twists and shapes them into weapons through which he questions and mocks society for its authoritarian and ideological flaws, and with which he exposes its conceptual and ethical blind spots. In this way, he acts like a mirror, reflecting what is wrong with society, and by implication, with the human ‘nature’ – not only in the fictional world of Gotham, but also in the contemporary era created therein. More specifically, discourse analysis and film analysis will be used here, to engage critically with the Joker’s persona in relation to the changing contexts in which the various films were made, in order to trace the development of the character through a Deleuzoguattarian lens. As will be discussed, Phillips’ Joker (2019) signals the deterritorialization of the Joker from the ambit of Batman’s influence, and opens up the possibility for his further deterritorialization as an increasingly mobile and nomadic catalyst of critical thinking beyond even Gotham itself. Then, thirdly, an in-depth analysis on the five key cinematic Jokers will be completed in terms of the characters’ historical contexts, character backgrounds, and aesthetics. And thereafter, the deterritorializing ‘line of flight’ already underway – as by Phillips’ Joker (2019) – will be continued through the creative media production component of this study, which will entail the conceptualization, design and illustration of three new Joker manifestations, each of which will reflect critically upon failing systems in South African society across select time periods, and how these failing systems have contributed to the collective trauma of marginalized groups of people. The first South African Joker manifestation, set in the 1980s, will reflect upon the faltering political infrastructure during the Apartheid era. The second Joker manifestation, set in the early 2000s, will encapsulate the repercussions of the post-Apartheid neoliberal economic landscape. And the third Joker manifestation, set in the 2010s, will draw attention to sociocultural collapse particularly in the space of gender-based violence and sexual assault. Thus, the creation of these Jokers will act as an exploration of trauma, insofar as the tragedy and pain caused by the above-mentioned failing systems will manifest physically through their character designs. In terms of this, and in keeping with the dynamics of appropriation and inflection that are definitive of nomadic war machines, here focus will fall on how their character aesthetics pose critical questions about relevant issues in the South Africa. On account of this, although this research is by definition situated within the spectacle/performance paradigm, it also runs counter to the largely apolitical orientation of creative media production that occurs therein, through its emphasis, instead, on how such creative media production can also entail critical thought that is aimed at thematizing socio-cultural and politico-economic issues and the trauma that they create; thus, this creative media component aims to encourage a more trauma-aware society through art. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2023
- Full Text:
- Date Issued: 2024-04
Out of place: an analysis of place as a contributor to the complexities of my “coloured” identity in Malabar, Gqeberha
- Authors: Flowers, Victoria
- Date: 2024-04
- Subjects: Colored people (South Africa) -- Race identity , Ethnicity in art -- South Africa -- Port Elizabeth , Modernism (Art)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62780 , vital:72954
- Description: Coloured identity has been a historical point of contestation in South Africa because Colouredness is assumed as “an inbred quality that arises automatically from miscegenation while instrumentalists share the essentialist premise that coloured identity is something negative and undesirable but blame it on the racism and the exploitative practices of the ruling white minority” (Adhikari, 2009: 15). This archaic belief attributed to racial mixture has now become redundant, due to the emergence of new hybridised Coloured identities that factor other ethnic and cultural groups as well as internal and external elements into their conception. The role of Place in the formation of Coloured identities is at the core of this fine arts based enquiry. This study is located in Malabar, Gqeberha which was established after the forced removals onset by the Group Areas Act of 1950 and the displacement of residents from South End. Additionally, it considers specific locations significant in their linkages to hybridised peoples, and how the place and individuals have been influenced by historical legacies of colonisation and apartheid. These are examined to consider their function in contextualising contemporary lived experiences of Coloured identity within the community of Malabar and its effect on artistic practice through autoethnographic research. Through this autoethnographic and reflexive study and the accompanying empirical research process, I critically examine and explore my Coloured identity as part of being-in-the-world (Heidegger, 1962). This ‘being’ is multifaceted as a result of the significance of Place in South Africa and how it has shaped my perception of how and where I have a sense of being and belonging. , Thesis (MA) -- Faculty of Humanities, School Visual and Performing Arts, 2023
- Full Text:
- Date Issued: 2024-04
- Authors: Flowers, Victoria
- Date: 2024-04
- Subjects: Colored people (South Africa) -- Race identity , Ethnicity in art -- South Africa -- Port Elizabeth , Modernism (Art)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62780 , vital:72954
- Description: Coloured identity has been a historical point of contestation in South Africa because Colouredness is assumed as “an inbred quality that arises automatically from miscegenation while instrumentalists share the essentialist premise that coloured identity is something negative and undesirable but blame it on the racism and the exploitative practices of the ruling white minority” (Adhikari, 2009: 15). This archaic belief attributed to racial mixture has now become redundant, due to the emergence of new hybridised Coloured identities that factor other ethnic and cultural groups as well as internal and external elements into their conception. The role of Place in the formation of Coloured identities is at the core of this fine arts based enquiry. This study is located in Malabar, Gqeberha which was established after the forced removals onset by the Group Areas Act of 1950 and the displacement of residents from South End. Additionally, it considers specific locations significant in their linkages to hybridised peoples, and how the place and individuals have been influenced by historical legacies of colonisation and apartheid. These are examined to consider their function in contextualising contemporary lived experiences of Coloured identity within the community of Malabar and its effect on artistic practice through autoethnographic research. Through this autoethnographic and reflexive study and the accompanying empirical research process, I critically examine and explore my Coloured identity as part of being-in-the-world (Heidegger, 1962). This ‘being’ is multifaceted as a result of the significance of Place in South Africa and how it has shaped my perception of how and where I have a sense of being and belonging. , Thesis (MA) -- Faculty of Humanities, School Visual and Performing Arts, 2023
- 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
The effectiveness of the findings of the auditor-general in the control of public funds: a case of Bojanala platinum District Municipality
- Authors: Tshivhenga, Gilbert
- Date: 2024-04
- Subjects: South Africa. -- Office of the Auditor-General -- Appropriations and expenditures , Finance, Public South Africa -- Auditing , Expenditures, Public -- Cost effectiveness
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62791 , vital:72957
- Description: The study aimed to investigate the effectiveness of the Auditor-General’s findings in controlling public funds, with specific reference to the Bojanala Platinum District Municipality. The research is comprised of six chapters. The research adopted the qualitative research methodology approach. The study provides academic input into public administration, specifically for improving service delivery performance, control and financial performance management in municipalities. The study could contribute to the establishment of effective methods for monitoring municipalities’ control of public funds. The research also identified several strengths and weaknesses of the BPDM, which are vital for effective and efficient service delivery to the community. It is envisaged that other municipalities in South Africa will learn something from it. Furthermore, this research study envisages promoting the best control of public funds within the BPDM and improving the efficiency and effectiveness of service delivery to ensure communities’ well-being and dignity. Based on the findings primarily from the literature review and empirical survey, various recommendations are presented on how the existing status quo of the BPDM can be changed to enhance the better control of public funds, which can assist in service delivery and are aligned with the Batho Pele principles. If these recommendations are adopted, the BPDM will be able to deal with the developmental obstacles it currently faces more effectively and efficiently. , Thesis (MPA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2023
- Full Text:
- Date Issued: 2024-04
- Authors: Tshivhenga, Gilbert
- Date: 2024-04
- Subjects: South Africa. -- Office of the Auditor-General -- Appropriations and expenditures , Finance, Public South Africa -- Auditing , Expenditures, Public -- Cost effectiveness
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62791 , vital:72957
- Description: The study aimed to investigate the effectiveness of the Auditor-General’s findings in controlling public funds, with specific reference to the Bojanala Platinum District Municipality. The research is comprised of six chapters. The research adopted the qualitative research methodology approach. The study provides academic input into public administration, specifically for improving service delivery performance, control and financial performance management in municipalities. The study could contribute to the establishment of effective methods for monitoring municipalities’ control of public funds. The research also identified several strengths and weaknesses of the BPDM, which are vital for effective and efficient service delivery to the community. It is envisaged that other municipalities in South Africa will learn something from it. Furthermore, this research study envisages promoting the best control of public funds within the BPDM and improving the efficiency and effectiveness of service delivery to ensure communities’ well-being and dignity. Based on the findings primarily from the literature review and empirical survey, various recommendations are presented on how the existing status quo of the BPDM can be changed to enhance the better control of public funds, which can assist in service delivery and are aligned with the Batho Pele principles. If these recommendations are adopted, the BPDM will be able to deal with the developmental obstacles it currently faces more effectively and efficiently. , Thesis (MPA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2023
- Full Text:
- Date Issued: 2024-04
The role of popular and traditional music during the umgidi initiation ceremonies among the Amampondo: subtitle if needed. If no subtitle follow instructions in manual
- Authors: Gushu, Lindokuhle
- Date: 2024-04
- Subjects: Xhosa (African people) -- Music , Folk music -- Social aspects -- South Africa -- Eastern Cape , Xhosa (African people) -- Rites and ceremonies , Popular music -- South Africa -- Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62805 , vital:72962
- Description: This study investigates the intricate dynamics of music within the umgidi initiation ceremonies among the amaMpondo, focusing on the interplay between traditional and modern popular music. The study explores the cultural foundation of the umgidi ceremony, emphasising its transformative significance and the evolving influence of modern popular music, particularly among the youth. A comprehensive literature review follows, contextualising the amaMpondo, their cultural practices, and the complex relationship between traditional and popular music in the broader South African music scene. The study adopted a qualitative ethnographic approach, including participant observation and individual interviews, to explore the impact of modern popular music on traditional elements during umgidi initiation ceremonies. Thematic analysis was employed for data interpretation, ensuring a systematic exploration of patterns and meanings. Ethical considerations were meticulously addressed, emphasising protecting participants' rights and cultural sensitivity. The study's findings highlighted the multifaceted roles of music during umgidi initiation ceremonies. Music is a powerful medium for cultural expression, communication, and communal celebration. The call-and-response format, rhythm variations, and the influence of modern genres such as Gqom and Amapiano were explored. Community attitudes toward integrating modern popular music reveal diverse opinions, ranging from full embrace to resistance. In summary, this study contributes to understanding the evolving dynamics of music in umgidi initiation ceremonies among the amaMpondo. The study provides a nuanced exploration and a roadmap for future research, community engagement, and policy considerations by combining cultural insights, literature review, methodological rigour, and community perspectives. , Thesis (MMus) -- Faculty of Humanities, School of Visual and Performing Arts, 2023
- Full Text:
- Date Issued: 2024-04
- Authors: Gushu, Lindokuhle
- Date: 2024-04
- Subjects: Xhosa (African people) -- Music , Folk music -- Social aspects -- South Africa -- Eastern Cape , Xhosa (African people) -- Rites and ceremonies , Popular music -- South Africa -- Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62805 , vital:72962
- Description: This study investigates the intricate dynamics of music within the umgidi initiation ceremonies among the amaMpondo, focusing on the interplay between traditional and modern popular music. The study explores the cultural foundation of the umgidi ceremony, emphasising its transformative significance and the evolving influence of modern popular music, particularly among the youth. A comprehensive literature review follows, contextualising the amaMpondo, their cultural practices, and the complex relationship between traditional and popular music in the broader South African music scene. The study adopted a qualitative ethnographic approach, including participant observation and individual interviews, to explore the impact of modern popular music on traditional elements during umgidi initiation ceremonies. Thematic analysis was employed for data interpretation, ensuring a systematic exploration of patterns and meanings. Ethical considerations were meticulously addressed, emphasising protecting participants' rights and cultural sensitivity. The study's findings highlighted the multifaceted roles of music during umgidi initiation ceremonies. Music is a powerful medium for cultural expression, communication, and communal celebration. The call-and-response format, rhythm variations, and the influence of modern genres such as Gqom and Amapiano were explored. Community attitudes toward integrating modern popular music reveal diverse opinions, ranging from full embrace to resistance. In summary, this study contributes to understanding the evolving dynamics of music in umgidi initiation ceremonies among the amaMpondo. The study provides a nuanced exploration and a roadmap for future research, community engagement, and policy considerations by combining cultural insights, literature review, methodological rigour, and community perspectives. , Thesis (MMus) -- Faculty of Humanities, School of Visual and Performing Arts, 2023
- Full Text:
- Date Issued: 2024-04
Tienerafrikaans: ’n studie van tienertaal, met spesiale verwysing na sleng, in twee Inxuba Yethemba (RSA-)skole
- Authors: Holland, Anil Juan
- Date: 2024-04
- Subjects: Afrikaans language -- Social aspects -- South Africa -- Eastern Cape , Afrikaanse taal -- Grammatika , Code switching (Linguistics)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62816 , vital:72980
- Description: It is understood that, for us humans to communicate with one another, we need language. Communication thus has a close relationship with society. But language changes and it has many varieties. On the one hand we have the standard variety of a language which is mostly used in formal situations, and on the other hand we have other varieties, which are mostly used in informal situations. Slang serves as an example of the latter and is chiefly used by adolescents – individuals between the ages of 13 and 19. As Saal and Lawrence (2019: 24) put it: young people are the agents of linguistic change. The researcher finds the language of teenagers quite interesting seeing that he is a teacher who frequently comes across words or phrases he has not heard or does not know the meaning of. The goal of this study is thus to investigate teenage language as phenomenon, with special reference to slang. This study examines slang words and expressions as they occur among teenagers in two Nxuba (formerly Cradock) schools, as well as find out why, when, and when the research group will not make use of slang. Nxuba forms part of the Inxuba Yethemba Municipality in the Eastern Cape. During the study general linguistic phenomena that occur among the teenagers in the given town are also investigated. These phenomena are analysed using the phonetic, phonological, morphological, syntactic, semantic, and lexical levels of variation. This study follows a qualitative approach with the help of questionnaires, direct observation, and focus group interviews as data collection methods. It was found that teenagers are highly creative and create novel words or give new meanings to words that already exist in the standard variety. The reasons why teenagers make use of slang is, among other things, to ease communication, for the fun of it, secrecy, and to enrich the standard variety. Slang is mostly used in informal situations and tends to be avoided in the presence of older persons, at church, and when doing schoolwork. There are also various linguistic phenomena that appear in teenagers’ general language usage: borrowing, reduction, homonyms, polysemes, and various phonological phenomena, among other. , Thesis (MA) -- Faculty of Humanities , School of Language, Media and Communication , 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Holland, Anil Juan
- Date: 2024-04
- Subjects: Afrikaans language -- Social aspects -- South Africa -- Eastern Cape , Afrikaanse taal -- Grammatika , Code switching (Linguistics)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62816 , vital:72980
- Description: It is understood that, for us humans to communicate with one another, we need language. Communication thus has a close relationship with society. But language changes and it has many varieties. On the one hand we have the standard variety of a language which is mostly used in formal situations, and on the other hand we have other varieties, which are mostly used in informal situations. Slang serves as an example of the latter and is chiefly used by adolescents – individuals between the ages of 13 and 19. As Saal and Lawrence (2019: 24) put it: young people are the agents of linguistic change. The researcher finds the language of teenagers quite interesting seeing that he is a teacher who frequently comes across words or phrases he has not heard or does not know the meaning of. The goal of this study is thus to investigate teenage language as phenomenon, with special reference to slang. This study examines slang words and expressions as they occur among teenagers in two Nxuba (formerly Cradock) schools, as well as find out why, when, and when the research group will not make use of slang. Nxuba forms part of the Inxuba Yethemba Municipality in the Eastern Cape. During the study general linguistic phenomena that occur among the teenagers in the given town are also investigated. These phenomena are analysed using the phonetic, phonological, morphological, syntactic, semantic, and lexical levels of variation. This study follows a qualitative approach with the help of questionnaires, direct observation, and focus group interviews as data collection methods. It was found that teenagers are highly creative and create novel words or give new meanings to words that already exist in the standard variety. The reasons why teenagers make use of slang is, among other things, to ease communication, for the fun of it, secrecy, and to enrich the standard variety. Slang is mostly used in informal situations and tends to be avoided in the presence of older persons, at church, and when doing schoolwork. There are also various linguistic phenomena that appear in teenagers’ general language usage: borrowing, reduction, homonyms, polysemes, and various phonological phenomena, among other. , Thesis (MA) -- Faculty of Humanities , School of Language, Media and Communication , 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
An architecture for feedback-driven learning analytics
- Authors: Winfield, Philip John
- Date: 2023-12
- Subjects: Educational statistics -- Data processing , Education -- Research -- Statistical methods , Teacher-student relationships
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62744 , vital:72935
- Description: Feedback from students provides an opportunity to gain insights into students’ learning behaviour and participation in higher education learning and teaching. Academic staff are expected to constantly review and improve the learning and teaching environment where feedback contributes vital information toward pedagogical decision-making. Reviewing student feedback is essential but time-consuming, making it crucial to explore more effective and efficient ways to analyse and present feedback that encourages intervention and support. The general design science research evaluation pattern guided the construction and evaluation of a Feedback-Driven Architecture (FDA) for Learning Analytics (LA) to address this problem. An FDA implementation using a suitable case demonstrated each component validating the feasibility and effectiveness of the proposed design. The components identified for inclusion in the FDA were integrated within layers of a three-tiered architecture pattern. The data layer incorporates the collection, preparation and storage of learning management system data which includes free-form narrative student feedback. The application layer contains logic to support the analysis of free-form narrative student feedback and extraction of learning analytics. Arrangement and visualisation of information in the presentation layer aim to promote appropriate intervention and support. Evaluation using a case study showed that the FDA provided necessary guidelines for developing an implementation that produced feedbackdriven learning analytics. Data preparation transformed unstructured data into a suitable representation for effective analysis. Cohorts within narrative feedback responses were identified using the k-means clustering algorithm and latent Dirichlet allocation. Logistic regression and support vector machines were applied as predictive models and trained using extracted quantitative markers to predict academic success. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Winfield, Philip John
- Date: 2023-12
- Subjects: Educational statistics -- Data processing , Education -- Research -- Statistical methods , Teacher-student relationships
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62744 , vital:72935
- Description: Feedback from students provides an opportunity to gain insights into students’ learning behaviour and participation in higher education learning and teaching. Academic staff are expected to constantly review and improve the learning and teaching environment where feedback contributes vital information toward pedagogical decision-making. Reviewing student feedback is essential but time-consuming, making it crucial to explore more effective and efficient ways to analyse and present feedback that encourages intervention and support. The general design science research evaluation pattern guided the construction and evaluation of a Feedback-Driven Architecture (FDA) for Learning Analytics (LA) to address this problem. An FDA implementation using a suitable case demonstrated each component validating the feasibility and effectiveness of the proposed design. The components identified for inclusion in the FDA were integrated within layers of a three-tiered architecture pattern. The data layer incorporates the collection, preparation and storage of learning management system data which includes free-form narrative student feedback. The application layer contains logic to support the analysis of free-form narrative student feedback and extraction of learning analytics. Arrangement and visualisation of information in the presentation layer aim to promote appropriate intervention and support. Evaluation using a case study showed that the FDA provided necessary guidelines for developing an implementation that produced feedbackdriven learning analytics. Data preparation transformed unstructured data into a suitable representation for effective analysis. Cohorts within narrative feedback responses were identified using the k-means clustering algorithm and latent Dirichlet allocation. Logistic regression and support vector machines were applied as predictive models and trained using extracted quantitative markers to predict academic success. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 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
Characterization of the coastal Aquifer of Gqeberha, South Africa : Developing a conceptual understanding
- Authors: Vandala, Bamanye
- Date: 2023-12
- Subjects: Aquifers -- South Africa -- Port Elizabeth , Groundwater ecology , Hydrogeology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62710 , vital:72932
- Description: The aquifer systems in Gqeberha are poorly understood due to a lack of groundwater studies within the area, and this is particularly the case for the coastal aquifer of Gqeberha. Amidst the water crisis the city is currently facing, groundwater has become crucial, with over 1000 boreholes reportedly drilled in the coastal area, most of which are residential. This has resulted in the need to conduct more groundwater studies in the area and in Nelson Mandela Bay. This study presents a detailed hydrogeological characterization of the coastal aquifer of Gqeberha. This was achieved through the use of different techniques, which include field mapping, geophysics, hydrochemistry, and pumping test analysis. The work was done on the coastal seeps of the Algoa Group Formation and the fractured aquifer of the Peninsula Formation. The results through mapping indicated an abundance of folds, faults, and fractures which all have implications for groundwater flow. The majority of fractures are striking in the NE-SW and NW-SE directions. The pumping test analysis also indicated fractal flow with significant matrix flow resulting in a dual porosity system up to at least 200m in depth. The transmissivity and storativity values range from 6.78 – 44.5 m2/day and 0.0172 – 0.0325, respectively. This is highly dependent on the fracture interconnectivity, which varies across the area and is higher at shallow depths, as suggested by the geophysical profiles. Geophysical profiles indicate that the contact between the Algoa Group Formations and the Peninsula Formation results in coastal seeps due to the difference in hydraulic conductivities. The hydrochemical analysis suggests that the seeps generally have Na-Cl and Ca-Mg-Cl water types. The groundwater in the eastern area has a Ca-HCO3 water type, and the groundwater in the western region has a Ca-Mg-Cl water type, with the Chelsea-Noordhoek Fault system separating the two groundwater signatures. Groundwater at greater depths has a Na-Cl water type with higher TDS values. The chemical signatures seen are due to external factors, which include sea sprays, anthropogenic activities, rock-water processes, and possibly connate water in the Peninsula Formation aquifer. The findings of this study offer valuable insights into the present conditions of the aquifer in Gqeberha. This research serves as a foundational study that can provide a baseline for future hydrogeological investigations in the area. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Vandala, Bamanye
- Date: 2023-12
- Subjects: Aquifers -- South Africa -- Port Elizabeth , Groundwater ecology , Hydrogeology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62710 , vital:72932
- Description: The aquifer systems in Gqeberha are poorly understood due to a lack of groundwater studies within the area, and this is particularly the case for the coastal aquifer of Gqeberha. Amidst the water crisis the city is currently facing, groundwater has become crucial, with over 1000 boreholes reportedly drilled in the coastal area, most of which are residential. This has resulted in the need to conduct more groundwater studies in the area and in Nelson Mandela Bay. This study presents a detailed hydrogeological characterization of the coastal aquifer of Gqeberha. This was achieved through the use of different techniques, which include field mapping, geophysics, hydrochemistry, and pumping test analysis. The work was done on the coastal seeps of the Algoa Group Formation and the fractured aquifer of the Peninsula Formation. The results through mapping indicated an abundance of folds, faults, and fractures which all have implications for groundwater flow. The majority of fractures are striking in the NE-SW and NW-SE directions. The pumping test analysis also indicated fractal flow with significant matrix flow resulting in a dual porosity system up to at least 200m in depth. The transmissivity and storativity values range from 6.78 – 44.5 m2/day and 0.0172 – 0.0325, respectively. This is highly dependent on the fracture interconnectivity, which varies across the area and is higher at shallow depths, as suggested by the geophysical profiles. Geophysical profiles indicate that the contact between the Algoa Group Formations and the Peninsula Formation results in coastal seeps due to the difference in hydraulic conductivities. The hydrochemical analysis suggests that the seeps generally have Na-Cl and Ca-Mg-Cl water types. The groundwater in the eastern area has a Ca-HCO3 water type, and the groundwater in the western region has a Ca-Mg-Cl water type, with the Chelsea-Noordhoek Fault system separating the two groundwater signatures. Groundwater at greater depths has a Na-Cl water type with higher TDS values. The chemical signatures seen are due to external factors, which include sea sprays, anthropogenic activities, rock-water processes, and possibly connate water in the Peninsula Formation aquifer. The findings of this study offer valuable insights into the present conditions of the aquifer in Gqeberha. This research serves as a foundational study that can provide a baseline for future hydrogeological investigations in the area. , 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
Field mapping and geochemistry of lower Jurassic sediments and volcanics of the upper Karoo supergroup near Ha Mosi, Lesotho mountains
- Authors: Valashiya, Khaya
- Date: 2023-12
- Subjects: Sediments (Geology) -- South Africa -- karoo basin , Geochemistry , Geological mapping
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62687 , vital:72925
- Description: Geological mapping in the Lesotho-Drakensberg Mountains spans over 100 years with du Toit and Stockley being the major contributors to the published maps and to the understanding of emplacement of the Karoo Large Igneous Province (KLIP) in the countries of South Africa and Lesotho. Despite the detailed previous work, there remains limited data on paleoenvironmental changes at the contact between the sedimentary and volcanic sequences of the upper Karoo Supergroup. This study aims to map the lithostratigraphic boundaries, volcano-sedimentary facies and faults near Ha Mosi in southern Lesotho. A total 48 rock samples were collected for petrography, XRF and ICP-MS analyses. The new results were used to characterize the local chemostratigraphy and to propose new regional correlations across Lesotho and South Africa. In this thesis, eight lithostratigraphic units were defined with a total thickness of 550 m. The first two units (Units 1 and 2) comprise massive and bedded sandstones, interpreted as possible floodplain and ephemeral lacustrine deposits; these are ascribed to the upper Stormberg Group. These units are unconformably overlain by locally preserved thin basaltic (Unit 3) flows that are characterised by high Zr/Nb and Zr/Y ratios; and low Ti/Zr and P/Zr ratios similar to the Golden Gate Unit of the Drakensberg Group. The lava flows are overlain by bedded sandstone ascribed to Unit 4 and volcaniclastic breccia ascribed to Units 5 and 6. Unit 6 consists of a monolithic breccia that is composed of angular sandstone clasts similar to those of the underlying Stormberg Group. The monolithic breccia transitions upwards into a massive megaclastic clast-supported volcanic breccia, which consists of angular to sub-rounded basaltic and doleritic boulders. Petrified wood fragments are found within the megaclastic breccia, indicating the presence of vegetation during deposition and enhanced preservation. Unit 6 laterally grades into Unit 5, which is characterised by poorly bedded breccia composed of angular sandstone, mudstone clasts with minor basaltic and doleritic clasts and, breccia intraclasts. The breccia units are often associated with reworked sediments interpreted to be deposited by fluvial systems. The breccia is conformably overlain by basaltic lava flows (Unit 8) characterised by high Ti/Zr and P/Zr ratios and moderate to low Zr/Y and Zr/Nb ratios compared to the Unit 3 lavas and is similar to that of the Sani Pass Unit of the Drakensberg Group. The basaltic sequences in the Ha Mosi studied area preserve both pahoehoe textures and pillow lavas, indicating subaerial and subaqueous volcanism. The studied lithologies are intruded by gabbro and dolerites of the Karoo Dolerite Suite at 183 Ma. This stratigraphy records the transition from sedimentation in the Karoo Basin through to a dominantly volcanic succession, which has importance in terms of the Toarcian extinction at ca. 182 Ma. Mapped faults and associated fractures are orientated predominantly NW-SE with the hanging walls moved maximum 80 m to the south. The different dykes and fault structures possibly relate to the Weddel Triple Junction that developed during the Early Jurassic break up of Gondwana, between 200 and 180 Ma. The mapped lavas show that the magma source was a chemically heterogenous mantle that was subjected to different degrees of partial melting, with the introduction of small-scale chemical heterogeneities. The geodynamic setting is comparable to the Afar Triangle of north-east Africa where active tectonics created a large-scale NW-SE orientated fault system in response to crustal thinning and rifting. In both the Afar and Lesotho, vertical movements created lowlands that allow for the preservation of volcanic breccia and basalts with pillow lavas. These findings show that existing geological models in the Drakensberg-Lesotho Mountains can be improved upon detailed field mapping and geochemistry. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Valashiya, Khaya
- Date: 2023-12
- Subjects: Sediments (Geology) -- South Africa -- karoo basin , Geochemistry , Geological mapping
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62687 , vital:72925
- Description: Geological mapping in the Lesotho-Drakensberg Mountains spans over 100 years with du Toit and Stockley being the major contributors to the published maps and to the understanding of emplacement of the Karoo Large Igneous Province (KLIP) in the countries of South Africa and Lesotho. Despite the detailed previous work, there remains limited data on paleoenvironmental changes at the contact between the sedimentary and volcanic sequences of the upper Karoo Supergroup. This study aims to map the lithostratigraphic boundaries, volcano-sedimentary facies and faults near Ha Mosi in southern Lesotho. A total 48 rock samples were collected for petrography, XRF and ICP-MS analyses. The new results were used to characterize the local chemostratigraphy and to propose new regional correlations across Lesotho and South Africa. In this thesis, eight lithostratigraphic units were defined with a total thickness of 550 m. The first two units (Units 1 and 2) comprise massive and bedded sandstones, interpreted as possible floodplain and ephemeral lacustrine deposits; these are ascribed to the upper Stormberg Group. These units are unconformably overlain by locally preserved thin basaltic (Unit 3) flows that are characterised by high Zr/Nb and Zr/Y ratios; and low Ti/Zr and P/Zr ratios similar to the Golden Gate Unit of the Drakensberg Group. The lava flows are overlain by bedded sandstone ascribed to Unit 4 and volcaniclastic breccia ascribed to Units 5 and 6. Unit 6 consists of a monolithic breccia that is composed of angular sandstone clasts similar to those of the underlying Stormberg Group. The monolithic breccia transitions upwards into a massive megaclastic clast-supported volcanic breccia, which consists of angular to sub-rounded basaltic and doleritic boulders. Petrified wood fragments are found within the megaclastic breccia, indicating the presence of vegetation during deposition and enhanced preservation. Unit 6 laterally grades into Unit 5, which is characterised by poorly bedded breccia composed of angular sandstone, mudstone clasts with minor basaltic and doleritic clasts and, breccia intraclasts. The breccia units are often associated with reworked sediments interpreted to be deposited by fluvial systems. The breccia is conformably overlain by basaltic lava flows (Unit 8) characterised by high Ti/Zr and P/Zr ratios and moderate to low Zr/Y and Zr/Nb ratios compared to the Unit 3 lavas and is similar to that of the Sani Pass Unit of the Drakensberg Group. The basaltic sequences in the Ha Mosi studied area preserve both pahoehoe textures and pillow lavas, indicating subaerial and subaqueous volcanism. The studied lithologies are intruded by gabbro and dolerites of the Karoo Dolerite Suite at 183 Ma. This stratigraphy records the transition from sedimentation in the Karoo Basin through to a dominantly volcanic succession, which has importance in terms of the Toarcian extinction at ca. 182 Ma. Mapped faults and associated fractures are orientated predominantly NW-SE with the hanging walls moved maximum 80 m to the south. The different dykes and fault structures possibly relate to the Weddel Triple Junction that developed during the Early Jurassic break up of Gondwana, between 200 and 180 Ma. The mapped lavas show that the magma source was a chemically heterogenous mantle that was subjected to different degrees of partial melting, with the introduction of small-scale chemical heterogeneities. The geodynamic setting is comparable to the Afar Triangle of north-east Africa where active tectonics created a large-scale NW-SE orientated fault system in response to crustal thinning and rifting. In both the Afar and Lesotho, vertical movements created lowlands that allow for the preservation of volcanic breccia and basalts with pillow lavas. These findings show that existing geological models in the Drakensberg-Lesotho Mountains can be improved upon detailed field mapping and geochemistry. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Functional traits and potential physical drivers of offshore benthic epifauna on the west and south coast of South Africa
- Van Stavel, Jordan, Morris, Tamaryn
- Authors: Van Stavel, Jordan , Morris, Tamaryn
- Date: 2023-12
- Subjects: Marine ecology , Marine biology -- South Africa , Oceanography -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62698 , vital:72931
- Description: Offshore benthic ecosystems (> 200 m depth) are challenging to access and remain poorly studied globally. Epifaunal invertebrates comprise a critical trophic level in benthic ecosystems and can serve as indicators of the overall health and functioning. There is limited knowledge of South Africa’s offshore marine environment and benthic ecosystem functioning due to limitations in funding, resources, and the lack of suitable science-based monitoring tools which are vital for sustainable management into the future. The aim of this research was to improve the understanding of epifaunal functioning as well as their potential physical drivers in 13 South African offshore biogeographic ecotypes. The objectives of this study were threefold: 1) to investigate the functional composition of benthic epifauna from 13 biogeographic ecotypes, 2) to quantify the Functional Diversity (FD) associated with epifaunal traits between the different assemblages (i.e. biogeographic ecotypes), and 3) to evaluate the relationship between physical variables and epifaunal functional traits at the biogeographic ecotype level. Biological trait-based approaches were applied to a subset of 80 benthic epifaunal species collected from 909 offshore stations along the west and south coasts of South Africa. Nine biological traits (associated with life history, morphology and behavioural characteristics exhibited by each species) were classified into 39 modalities and weighted with biomass. Community Weighted Means (CWMs) were used to evaluate the benthic epifaunal functional trait composition of the 13 biogeographic ecotypes. Functional composition across the 13 ecotype assemblages on the west and south coast appeared to be dominated by species with similar trait compositions, such as large, long-lived, surface crawling/burrowing/filter-feeding epifauna with medium to no mobility, however, their percentage of contribution to trait expression (CWMs) was higher on the west coast. Functional diversity indices (alpha and beta) showed higher overall FD for west coast ecotypes, with most ecotypes on the continental shelf (except slopes and canyons) being significantly different (p<0.05) from ecotypes on the south coast. The global RLQ (three-table co-inertia) test did not reveal a significant relationship between biomass and physical variables or between biomass and traits (p>0.05). The fourth-corner method was used to test the significance of individual traitenvironment relationships. The fourth-corner results were similar overall to the RLQ analysis, revealing that three physical variables (temperature, depth, and fluorescence) were significantly correlated to two trait modalities belonging to the feeding mode filter-feeders (FM1) and scavengers (FM5). Scavengers were positively correlated with depth and negatively with temperature, while filter-feeders were positively correlated with fluorescence levels. This indicated that the presence of scavenging epifauna increased with a decrease in temperature and an increase in depth. While a positive significant correlation between filter-feeders and fluorescence suggested their potential tolerance or preference for environmental conditions with high levels of fluorescence. This research was the first such study to explore the functional composition and diversity of benthic epifauna and their relationship with potential physical drivers in offshore west and south coast benthic biogeographic ecotypes of South Africa. The application of new tools to quantify the functional diversity of epifauna as indicators of ecosystem health, and their potential physical drivers. This provided a platform on which to advance our understanding of benthic communities and the roles they play in ecosystem functioning under changing environments. Functional trait-based approaches such as those applied in this study can provide us with vital information on the relationship between biodiversity, ecosystem functioning, and physical drivers. Environmental stressors and changing climate patterns threaten to impact marine ecosystems and their functioning. Benthic epifauna are especially sensitive to changes in their environment and these fluctuations could potentially lead to the loss of certain benthic functionality, altering the thresholds these ecosystems have to response to disturbances. This undermines the stability of these ecosystems which can have ripple effects on the health of these ecosystems and their ability to provide the ecosystem services humans dependent on. Having suitable tools to track current and predict future changes will therefore be vital to inform management and conservation strategies for sustainable ocean utilisation. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Van Stavel, Jordan , Morris, Tamaryn
- Date: 2023-12
- Subjects: Marine ecology , Marine biology -- South Africa , Oceanography -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62698 , vital:72931
- Description: Offshore benthic ecosystems (> 200 m depth) are challenging to access and remain poorly studied globally. Epifaunal invertebrates comprise a critical trophic level in benthic ecosystems and can serve as indicators of the overall health and functioning. There is limited knowledge of South Africa’s offshore marine environment and benthic ecosystem functioning due to limitations in funding, resources, and the lack of suitable science-based monitoring tools which are vital for sustainable management into the future. The aim of this research was to improve the understanding of epifaunal functioning as well as their potential physical drivers in 13 South African offshore biogeographic ecotypes. The objectives of this study were threefold: 1) to investigate the functional composition of benthic epifauna from 13 biogeographic ecotypes, 2) to quantify the Functional Diversity (FD) associated with epifaunal traits between the different assemblages (i.e. biogeographic ecotypes), and 3) to evaluate the relationship between physical variables and epifaunal functional traits at the biogeographic ecotype level. Biological trait-based approaches were applied to a subset of 80 benthic epifaunal species collected from 909 offshore stations along the west and south coasts of South Africa. Nine biological traits (associated with life history, morphology and behavioural characteristics exhibited by each species) were classified into 39 modalities and weighted with biomass. Community Weighted Means (CWMs) were used to evaluate the benthic epifaunal functional trait composition of the 13 biogeographic ecotypes. Functional composition across the 13 ecotype assemblages on the west and south coast appeared to be dominated by species with similar trait compositions, such as large, long-lived, surface crawling/burrowing/filter-feeding epifauna with medium to no mobility, however, their percentage of contribution to trait expression (CWMs) was higher on the west coast. Functional diversity indices (alpha and beta) showed higher overall FD for west coast ecotypes, with most ecotypes on the continental shelf (except slopes and canyons) being significantly different (p<0.05) from ecotypes on the south coast. The global RLQ (three-table co-inertia) test did not reveal a significant relationship between biomass and physical variables or between biomass and traits (p>0.05). The fourth-corner method was used to test the significance of individual traitenvironment relationships. The fourth-corner results were similar overall to the RLQ analysis, revealing that three physical variables (temperature, depth, and fluorescence) were significantly correlated to two trait modalities belonging to the feeding mode filter-feeders (FM1) and scavengers (FM5). Scavengers were positively correlated with depth and negatively with temperature, while filter-feeders were positively correlated with fluorescence levels. This indicated that the presence of scavenging epifauna increased with a decrease in temperature and an increase in depth. While a positive significant correlation between filter-feeders and fluorescence suggested their potential tolerance or preference for environmental conditions with high levels of fluorescence. This research was the first such study to explore the functional composition and diversity of benthic epifauna and their relationship with potential physical drivers in offshore west and south coast benthic biogeographic ecotypes of South Africa. The application of new tools to quantify the functional diversity of epifauna as indicators of ecosystem health, and their potential physical drivers. This provided a platform on which to advance our understanding of benthic communities and the roles they play in ecosystem functioning under changing environments. Functional trait-based approaches such as those applied in this study can provide us with vital information on the relationship between biodiversity, ecosystem functioning, and physical drivers. Environmental stressors and changing climate patterns threaten to impact marine ecosystems and their functioning. Benthic epifauna are especially sensitive to changes in their environment and these fluctuations could potentially lead to the loss of certain benthic functionality, altering the thresholds these ecosystems have to response to disturbances. This undermines the stability of these ecosystems which can have ripple effects on the health of these ecosystems and their ability to provide the ecosystem services humans dependent on. Having suitable tools to track current and predict future changes will therefore be vital to inform management and conservation strategies for sustainable ocean utilisation. , Thesis (MSc) -- Faculty of Science, School of Environmental 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