The incorporation of GeoGebra as a visualisation tool to teach calculus in teacher education institutions: the Zambian case
- Authors: Kangwa, Lemmy
- Date: 2022-10-14
- Subjects: GeoGebra , Calculus Study and teaching (Secondary) Zambia , Visual learning
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405470 , vital:70174 , DOI
- Description: This qualitative case study investigated teacher educators’ (lecturers) use of the dynamic mathematics software, GeoGebra, to teach calculus in three teacher education institutions (TEIs) in Zambia. Visualisation, a key characteristic of GeoGebra, is increasingly gaining recognition of playing a critical role in mathematics teaching and learning, especially in problem solving tasks. It is considered a powerful didactical tool for students to construct mental and physical representations that can enhance conceptual understanding of mathematics. GeoGebra is a visualisation tool that can be used for problem-oriented teaching and foster mathematical experiments and discoveries. GeoGebra’s inherent visualisation characteristics align well with the teaching of calculus, the mathematical domain of this study. The study (whose research methodology was underpinned by the interpretive paradigm) was undertaken with a broader goal of designing and implementing GeoGebra applets and instructional materials on various calculus topics. The study is located within the “Teaching and Learning Mathematics with GeoGebra (TLMG) project” – a project that involves mathematics teachers and lecturers in Zambia. The case in this study is the six mathematics lecturers who co-designed and used GeoGebra applets to teach derivatives and integrals to pre-service mathematics teachers in TEIs. The unit of analysis therefore is the six lecturers’ use of GeoGebra as a visualisation tool to teach calculus to enhance conceptual understanding, their perceptions and experiences of using GeoGebra and the enabling and constraining factors of using GeoGebra to teach and learn mathematics. The data for the study were video recordings of observations and interviews of lecturers. The data was analysed thematically and was guided and informed by an analytical framework adopted from the theory of constructivism – the umbrella theoretical framework of this study – and the models of Technological Pedagogical Content Knowledge (TPACK), and the Technology Acceptance Model (TAM). A detailed analysis of the lecturers’ interactions with the applets enabled me to gain insights into the participants’ experiences and perceptions of GeoGebra applets in the teaching and learning process. The findings of the study revealed that the visualisation characteristics of GeoGebra generally enhanced the conceptual understanding of calculus. It also revealed that adequate training, coupled with sufficient knowledge of the subject matter in calculus, were necessary for lecturers to use GeoGebra effectively, and that the lack of resources and expertise were major hindrances in the use of GeoGebra to teach mathematics in TEIs. It also revealed that there is a need to equip GeoGebra with other features that would make it more versatile, and suggested a teaching approach that would complement the use of conventional methods and GeoGebra to provide a link between abstract and concrete concepts of calculus. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Authors: Kangwa, Lemmy
- Date: 2022-10-14
- Subjects: GeoGebra , Calculus Study and teaching (Secondary) Zambia , Visual learning
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405470 , vital:70174 , DOI
- Description: This qualitative case study investigated teacher educators’ (lecturers) use of the dynamic mathematics software, GeoGebra, to teach calculus in three teacher education institutions (TEIs) in Zambia. Visualisation, a key characteristic of GeoGebra, is increasingly gaining recognition of playing a critical role in mathematics teaching and learning, especially in problem solving tasks. It is considered a powerful didactical tool for students to construct mental and physical representations that can enhance conceptual understanding of mathematics. GeoGebra is a visualisation tool that can be used for problem-oriented teaching and foster mathematical experiments and discoveries. GeoGebra’s inherent visualisation characteristics align well with the teaching of calculus, the mathematical domain of this study. The study (whose research methodology was underpinned by the interpretive paradigm) was undertaken with a broader goal of designing and implementing GeoGebra applets and instructional materials on various calculus topics. The study is located within the “Teaching and Learning Mathematics with GeoGebra (TLMG) project” – a project that involves mathematics teachers and lecturers in Zambia. The case in this study is the six mathematics lecturers who co-designed and used GeoGebra applets to teach derivatives and integrals to pre-service mathematics teachers in TEIs. The unit of analysis therefore is the six lecturers’ use of GeoGebra as a visualisation tool to teach calculus to enhance conceptual understanding, their perceptions and experiences of using GeoGebra and the enabling and constraining factors of using GeoGebra to teach and learn mathematics. The data for the study were video recordings of observations and interviews of lecturers. The data was analysed thematically and was guided and informed by an analytical framework adopted from the theory of constructivism – the umbrella theoretical framework of this study – and the models of Technological Pedagogical Content Knowledge (TPACK), and the Technology Acceptance Model (TAM). A detailed analysis of the lecturers’ interactions with the applets enabled me to gain insights into the participants’ experiences and perceptions of GeoGebra applets in the teaching and learning process. The findings of the study revealed that the visualisation characteristics of GeoGebra generally enhanced the conceptual understanding of calculus. It also revealed that adequate training, coupled with sufficient knowledge of the subject matter in calculus, were necessary for lecturers to use GeoGebra effectively, and that the lack of resources and expertise were major hindrances in the use of GeoGebra to teach mathematics in TEIs. It also revealed that there is a need to equip GeoGebra with other features that would make it more versatile, and suggested a teaching approach that would complement the use of conventional methods and GeoGebra to provide a link between abstract and concrete concepts of calculus. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
The nexus between Community Engagement and Academic Language Development
- Authors: Thondhlana, Mazvita Mollin
- Date: 2022-10-14
- Subjects: Community engagement , Service learning Study and teaching (Higher) South Africa , Education, Higher Social aspects South Africa , Community and college South Africa , Academic writing Study and teaching (Higher) South Africa , Information literacy Study and teaching (Higher) South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405509 , vital:70177 , DOI 10.21504/10962/405509
- Description: Community engagement (CE) is now widely considered a core function of higher education worldwide. In South African higher education institutions (HEIs), there is an increasing focus on CE as a means of transforming the role of the university in society, though the forms and shapes of CE vary by institution. CE is positioned as part of the means of addressing the challenges within the South African education system, such as ensuring equity in academic access in the face of diversity and making sure higher education institutions are responsive to the needs of society. Community Engagement is increasingly being afforded the same status as teaching and learning and research in higher education. The idea that higher education should function as a public good is central to this. This study reflects on how CE can be expansively viewed as places of learning for students to achieve epistemic access with epistemic justice, particularly in increasing diverse and changing contexts. Despite the growing research on CE in HEIs, there is comparatively limited focus on the intersection between CE and language use and potential linkages with identity and epistemic access and success. Given that one of the major challenges in South African HEIs relate to difficulties experienced by students whose home language is not English, the experiences of students learning within CE contexts within those institutions warrants investigation. The main aim of this study was to explore second language English speaking students’ experiences of language in the Engaged Citizen Programme, a Community Engagement programme at Rhodes University aimed at offering students the opportunity of enhanced learning, giving students the opportunity to evaluate the theories and ideas taught in the university against the realities of the South African context. The programme is also intended to offer students the opportunity to learn with and from communities and thereby enable personal growth (ECP Handbook: 2020; p.3). Using an in-depth phenomenological approach, this study explored diverse students’ experiences of language use in both community engaged programmes and in the classroom as a basis for understanding the role language plays in such spaces and the impact of these programmes on epistemic access, justice and success for students in HEIs. The study explored the role that CE plays for second language English students as they navigate complex questions of identity and belonging in HEIs. In CE activities, such as the Engaged Citizen Programme, unlike traditional classroom learning, English is often not the medium of instruction, as learning takes place in community sites, where multiple other languages are spoken. In the traditional classrooms, English is the dominant medium of instruction which can bring challenges for students whose home language is not English. Students are faced with various challenges including failure to communicate effectively and understand content knowledge. Significantly this study found that this often related to a sense of self-worth and belonging and constrained their participation and engagement in class. It was evident from the students’ reflections on their experiences in the Engaged Citizen Programme that CE provided a more flexible space generally more comfortable to these participants; a space that promotes engaged learning without rigid rules. The students’ reflections affirmed the contribution of CE in promoting engagement of students outside the formal classes and enhancing the ways in which they use language freely. It was also evident from the students’ reflections that CE provided a space in which students can identify who they are and have a sense of belonging. In the context of diversity, the majority of the students said they come to the university feeling a level of under preparedness and cannot identity with dominant groups. The reflections from the students’ experiences therefore offer some insights into ways in which we can actively promote CE in supporting student access and addressing issues of epistemic justice in higher education. The findings suggest that many of the benefits of CE, such as higher levels of interaction and significant amounts of translanguaging, need to be brought into the formal classroom spaces because they enhanced student engagement. While CE was also seen to be challenging and there were calls for more support, the essence of the experience was as a space of personal development and awareness of social responsibility. The explicit normative value of CE was in contrast to the absence of such considerations in the formal HE curriculum and the student experiences suggest that much could be learned from this. The use of English, both on campus and in CE activities, was found to be value-laden and politically charged. The participants, black students who spoke English as an additional language, all related experiences of English being positioned as a ‘superior’ language. The students who were highly fluent in English experienced being positioned as ‘showing off’ and seen to have ‘forgotten their roots’. Students who were not highly fluent in English, on the other hand, often constrained their participation in class because they experienced concern that their mispronunciations and accents may be mocked. The essence of the experience of language use in both formal classroom settings and in CE activities is that this is tightly bound to identity and is ideologically fraught. This requires more explicit conversation in all learning spaces. , Kubatirana pamwe nenharaunda (KPN) (CE) iko zvino kwave kutariswa zvakanyanya sembiru yebasa redzidzo yepamusoro pasirese. MuSouth Africa muzvikoro zvedzidzo yepamusoro (ZZY) (HEIs), kune kuwedzera kwekupa nguva kuKPN kunyangwe mamiriro uye maumbirwo eKPN achisiyana zvichienderana nechikoro chacho. Nematambudziko ari mukati memunezvedzidzo muSouth Africa uye nekumwewo, sekuenzanisira mukuwanikwa kwedzidzo mukusiyana kwevanhu nemaitiro uye kuona kuti zvikoro zvepamusoro zvinoteerera zvinodiwa munharaunda, KPN yaakupihwa kukosha kumwechete nekudzidzisa nekudzidza uyewonetsvagiridzo mudzidzo yepamusoro nechinangwa chekushandura nzira idzo ruzivo rwunoshandurwa mukushanda kwedzidzo yepamusoro sechinhu chakanakira munhu wese (ona Bhagwan: 2017). Shanduko yemaonero ekugadzirwa kwezivo nebasa remayunivhesiti mumagariro, kubva kunzira dzakare dzekuzvionera pamusoro kuenda kumayunivhesiti anobatikana nenharaunda zvinoonekwa senzira chaiyo yekuzadzisa chinangwa chekuti mayunivhesiti ave anodavira kune zvakapoteredza, aine mutoro nazvo uye achiunza shanduko. Pamwongo wemakakatanwa anechekuita neKPN panenyaya yekuti KPN inogona kutariswa zvakanyanya sevanze dzekudzidza dzevadzidzi uye kuwana kupinda munezveruzivo nezvekururamisira, kunyanya mukuwedzera kwokusiyana nekushanduka kwemamiriro ezvinhu. Zvakadaro, kunyangwe paine kukura mukufarirwa kweKPN muZZY, kune kushomeka kwekutarisa panosangana KPN nekushandiswa kwemutauro uye hukama nezvekuti unozviti uri ani uye kuwana kupinda munezvezivo nekubudirira. Muchiitiko chekudzidza kuburikidza nezviitwa zveKPN, zvichisiyana nekudzidza muimba yekudzidzira (kirasi) kwagara kuripo muZZY, Chirungu hachisiriicho nzira yekuraira nayo, sezvo kudzidza kuchiitika munzvimbo dzirimunharaunda. Mumakirasi ekudzidza kwagara kuripo, Chirungu ndomutauro unonyanyoshandiswa pakurairidza izvo zvinogona kuita kuti vadzidzi vanotaura mutauro usiri Chirungu kumba vatarisane nematambudziko anosanganisira kukundikana kutaura zvavarikuda, kuvenehukama nezvirikuitika chaizvo uye kunzwisisa ruzivo rwezvinodzidzwa zvinogona kukanganisa kutora chikamu kwavo nokubatirana kwavo nezvinengezvichiitika mukirasi. Nokuda kwokuti rimwe rematambudziko makuru muZZY zvemuSouth Africa rinechekuita nezvinetso zvinosangana nevadzidzi vane mutauro wekumba usiri Chirungu, panefaniro yekuoongorora zvinosanganikwa nazvo nevadzidzi mukati meKPN. Wongororo iyi idavidzo kumukaha uwu. Chinangwa chikuru chewongororo iyi chachiri chekuongorora zvinosanganikwa nazvo nevadzidzi vanotaura Chirungu semutauro wechipiri muEngaged Citizen Programme, chirongwa cheCommunity Engagement chine chinangwa chekupa vadzidzi mukana wekusimudzira madzidziro, kupa vadzidzi mukana wekuyera/kuongorora pfungwa dzirimukudzidza nemaonero munezvinodzidziswa muyunivhesiti zvichiyenzaniswa nezviri kuitika muSouth Africa pamwe nekupa vadzidzi mukana wekudzidza kubva kune nepamwe nenharaunda zvichitungamirira kukukura semunhu mumwe nemumwe (ECP Handbook: 2020; p.3) paRhodes University, inovayunivhesiti inoshandisaChirungu pakurairidza. Ichishandisa nemaitiro akadzama nzira yekuongorora inonzi phenomenological approach wongororo iyi yakatarisa zvinosanganikwa nazvo zvevadzidzi vakasiyana-siyana mukushandiswa kwemutauro muzvirongwa zvokubatirana pamwe nenharaunda uye mukirasi sehwaro hwekunzwisisa zvibereko zvezvirongwa izvi pakuwanikwa kwezvezivo, kururamisira uye kubudirira kwevadzidzi muZZY. Wongororo iyi yangayakanangawo zvakare kuongorora basa rinoitwa neKPN kuvadzidzi avo mutauro wechipiri urichiRungu pavanenge vachiedza kupindura mibvunzo yakaoma inechekuita nezvekuti ndivanaani uye nekuva kwavo chikamu chemuZZY. Zvakava pachena kubva mukufungisisa kwevadzidzi pamusoro pekuvevangavarimuchirongwa Engaged Citizen Programme kuti KPN kwakavapa nzvimbo yakasununguka uye yakagadzikana, inosimudzira kudzidza kunobata pasina mitemo yakaoma/isingashandurwi. Kufungisisa kwevadzidzi kwakasimbisa zvinounzwa neKPN mukusimudzira kuvanechekuita kwevadzidzi munezvinoitika kunze kwemakirasi nekusimudzira nzira dzavanoshandisa mutauro nadzo vakasununguka. Zvaivawo pachena kubva mukufungisisa kwevadzidzi kuti CE yakapa nzvimbo yekuti vadzidzi vazive kuti ndivanaani uye kuti vanzwe kuti ndevepi. Mumamiriro ekusiyana kwezvinhu, vazhinji vevadzidzi vakati vanouya kuyunivhesiti vachinzwa vaine chiyero chekugadzirira chepasi uye vasingagoni kufambidzana nevemapoka aripamusoro/anemukundo. Zvakabuda mukufungisisa kwevadzidzi pamusoro pezvavakapinda mazviri/zvavakasangana nazvo zvinopa mamwe manzwisisiro atingashandisa enzira dzatingashingairira nadzo kusimudzira CE mukutsigira vadzidzi kuwana kupinda nekugadzirisa nyaya dzekururamisira munezvezivo mudzidzo yepamusoro. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2022
- Full Text:
- Authors: Thondhlana, Mazvita Mollin
- Date: 2022-10-14
- Subjects: Community engagement , Service learning Study and teaching (Higher) South Africa , Education, Higher Social aspects South Africa , Community and college South Africa , Academic writing Study and teaching (Higher) South Africa , Information literacy Study and teaching (Higher) South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405509 , vital:70177 , DOI 10.21504/10962/405509
- Description: Community engagement (CE) is now widely considered a core function of higher education worldwide. In South African higher education institutions (HEIs), there is an increasing focus on CE as a means of transforming the role of the university in society, though the forms and shapes of CE vary by institution. CE is positioned as part of the means of addressing the challenges within the South African education system, such as ensuring equity in academic access in the face of diversity and making sure higher education institutions are responsive to the needs of society. Community Engagement is increasingly being afforded the same status as teaching and learning and research in higher education. The idea that higher education should function as a public good is central to this. This study reflects on how CE can be expansively viewed as places of learning for students to achieve epistemic access with epistemic justice, particularly in increasing diverse and changing contexts. Despite the growing research on CE in HEIs, there is comparatively limited focus on the intersection between CE and language use and potential linkages with identity and epistemic access and success. Given that one of the major challenges in South African HEIs relate to difficulties experienced by students whose home language is not English, the experiences of students learning within CE contexts within those institutions warrants investigation. The main aim of this study was to explore second language English speaking students’ experiences of language in the Engaged Citizen Programme, a Community Engagement programme at Rhodes University aimed at offering students the opportunity of enhanced learning, giving students the opportunity to evaluate the theories and ideas taught in the university against the realities of the South African context. The programme is also intended to offer students the opportunity to learn with and from communities and thereby enable personal growth (ECP Handbook: 2020; p.3). Using an in-depth phenomenological approach, this study explored diverse students’ experiences of language use in both community engaged programmes and in the classroom as a basis for understanding the role language plays in such spaces and the impact of these programmes on epistemic access, justice and success for students in HEIs. The study explored the role that CE plays for second language English students as they navigate complex questions of identity and belonging in HEIs. In CE activities, such as the Engaged Citizen Programme, unlike traditional classroom learning, English is often not the medium of instruction, as learning takes place in community sites, where multiple other languages are spoken. In the traditional classrooms, English is the dominant medium of instruction which can bring challenges for students whose home language is not English. Students are faced with various challenges including failure to communicate effectively and understand content knowledge. Significantly this study found that this often related to a sense of self-worth and belonging and constrained their participation and engagement in class. It was evident from the students’ reflections on their experiences in the Engaged Citizen Programme that CE provided a more flexible space generally more comfortable to these participants; a space that promotes engaged learning without rigid rules. The students’ reflections affirmed the contribution of CE in promoting engagement of students outside the formal classes and enhancing the ways in which they use language freely. It was also evident from the students’ reflections that CE provided a space in which students can identify who they are and have a sense of belonging. In the context of diversity, the majority of the students said they come to the university feeling a level of under preparedness and cannot identity with dominant groups. The reflections from the students’ experiences therefore offer some insights into ways in which we can actively promote CE in supporting student access and addressing issues of epistemic justice in higher education. The findings suggest that many of the benefits of CE, such as higher levels of interaction and significant amounts of translanguaging, need to be brought into the formal classroom spaces because they enhanced student engagement. While CE was also seen to be challenging and there were calls for more support, the essence of the experience was as a space of personal development and awareness of social responsibility. The explicit normative value of CE was in contrast to the absence of such considerations in the formal HE curriculum and the student experiences suggest that much could be learned from this. The use of English, both on campus and in CE activities, was found to be value-laden and politically charged. The participants, black students who spoke English as an additional language, all related experiences of English being positioned as a ‘superior’ language. The students who were highly fluent in English experienced being positioned as ‘showing off’ and seen to have ‘forgotten their roots’. Students who were not highly fluent in English, on the other hand, often constrained their participation in class because they experienced concern that their mispronunciations and accents may be mocked. The essence of the experience of language use in both formal classroom settings and in CE activities is that this is tightly bound to identity and is ideologically fraught. This requires more explicit conversation in all learning spaces. , Kubatirana pamwe nenharaunda (KPN) (CE) iko zvino kwave kutariswa zvakanyanya sembiru yebasa redzidzo yepamusoro pasirese. MuSouth Africa muzvikoro zvedzidzo yepamusoro (ZZY) (HEIs), kune kuwedzera kwekupa nguva kuKPN kunyangwe mamiriro uye maumbirwo eKPN achisiyana zvichienderana nechikoro chacho. Nematambudziko ari mukati memunezvedzidzo muSouth Africa uye nekumwewo, sekuenzanisira mukuwanikwa kwedzidzo mukusiyana kwevanhu nemaitiro uye kuona kuti zvikoro zvepamusoro zvinoteerera zvinodiwa munharaunda, KPN yaakupihwa kukosha kumwechete nekudzidzisa nekudzidza uyewonetsvagiridzo mudzidzo yepamusoro nechinangwa chekushandura nzira idzo ruzivo rwunoshandurwa mukushanda kwedzidzo yepamusoro sechinhu chakanakira munhu wese (ona Bhagwan: 2017). Shanduko yemaonero ekugadzirwa kwezivo nebasa remayunivhesiti mumagariro, kubva kunzira dzakare dzekuzvionera pamusoro kuenda kumayunivhesiti anobatikana nenharaunda zvinoonekwa senzira chaiyo yekuzadzisa chinangwa chekuti mayunivhesiti ave anodavira kune zvakapoteredza, aine mutoro nazvo uye achiunza shanduko. Pamwongo wemakakatanwa anechekuita neKPN panenyaya yekuti KPN inogona kutariswa zvakanyanya sevanze dzekudzidza dzevadzidzi uye kuwana kupinda munezveruzivo nezvekururamisira, kunyanya mukuwedzera kwokusiyana nekushanduka kwemamiriro ezvinhu. Zvakadaro, kunyangwe paine kukura mukufarirwa kweKPN muZZY, kune kushomeka kwekutarisa panosangana KPN nekushandiswa kwemutauro uye hukama nezvekuti unozviti uri ani uye kuwana kupinda munezvezivo nekubudirira. Muchiitiko chekudzidza kuburikidza nezviitwa zveKPN, zvichisiyana nekudzidza muimba yekudzidzira (kirasi) kwagara kuripo muZZY, Chirungu hachisiriicho nzira yekuraira nayo, sezvo kudzidza kuchiitika munzvimbo dzirimunharaunda. Mumakirasi ekudzidza kwagara kuripo, Chirungu ndomutauro unonyanyoshandiswa pakurairidza izvo zvinogona kuita kuti vadzidzi vanotaura mutauro usiri Chirungu kumba vatarisane nematambudziko anosanganisira kukundikana kutaura zvavarikuda, kuvenehukama nezvirikuitika chaizvo uye kunzwisisa ruzivo rwezvinodzidzwa zvinogona kukanganisa kutora chikamu kwavo nokubatirana kwavo nezvinengezvichiitika mukirasi. Nokuda kwokuti rimwe rematambudziko makuru muZZY zvemuSouth Africa rinechekuita nezvinetso zvinosangana nevadzidzi vane mutauro wekumba usiri Chirungu, panefaniro yekuoongorora zvinosanganikwa nazvo nevadzidzi mukati meKPN. Wongororo iyi idavidzo kumukaha uwu. Chinangwa chikuru chewongororo iyi chachiri chekuongorora zvinosanganikwa nazvo nevadzidzi vanotaura Chirungu semutauro wechipiri muEngaged Citizen Programme, chirongwa cheCommunity Engagement chine chinangwa chekupa vadzidzi mukana wekusimudzira madzidziro, kupa vadzidzi mukana wekuyera/kuongorora pfungwa dzirimukudzidza nemaonero munezvinodzidziswa muyunivhesiti zvichiyenzaniswa nezviri kuitika muSouth Africa pamwe nekupa vadzidzi mukana wekudzidza kubva kune nepamwe nenharaunda zvichitungamirira kukukura semunhu mumwe nemumwe (ECP Handbook: 2020; p.3) paRhodes University, inovayunivhesiti inoshandisaChirungu pakurairidza. Ichishandisa nemaitiro akadzama nzira yekuongorora inonzi phenomenological approach wongororo iyi yakatarisa zvinosanganikwa nazvo zvevadzidzi vakasiyana-siyana mukushandiswa kwemutauro muzvirongwa zvokubatirana pamwe nenharaunda uye mukirasi sehwaro hwekunzwisisa zvibereko zvezvirongwa izvi pakuwanikwa kwezvezivo, kururamisira uye kubudirira kwevadzidzi muZZY. Wongororo iyi yangayakanangawo zvakare kuongorora basa rinoitwa neKPN kuvadzidzi avo mutauro wechipiri urichiRungu pavanenge vachiedza kupindura mibvunzo yakaoma inechekuita nezvekuti ndivanaani uye nekuva kwavo chikamu chemuZZY. Zvakava pachena kubva mukufungisisa kwevadzidzi pamusoro pekuvevangavarimuchirongwa Engaged Citizen Programme kuti KPN kwakavapa nzvimbo yakasununguka uye yakagadzikana, inosimudzira kudzidza kunobata pasina mitemo yakaoma/isingashandurwi. Kufungisisa kwevadzidzi kwakasimbisa zvinounzwa neKPN mukusimudzira kuvanechekuita kwevadzidzi munezvinoitika kunze kwemakirasi nekusimudzira nzira dzavanoshandisa mutauro nadzo vakasununguka. Zvaivawo pachena kubva mukufungisisa kwevadzidzi kuti CE yakapa nzvimbo yekuti vadzidzi vazive kuti ndivanaani uye kuti vanzwe kuti ndevepi. Mumamiriro ekusiyana kwezvinhu, vazhinji vevadzidzi vakati vanouya kuyunivhesiti vachinzwa vaine chiyero chekugadzirira chepasi uye vasingagoni kufambidzana nevemapoka aripamusoro/anemukundo. Zvakabuda mukufungisisa kwevadzidzi pamusoro pezvavakapinda mazviri/zvavakasangana nazvo zvinopa mamwe manzwisisiro atingashandisa enzira dzatingashingairira nadzo kusimudzira CE mukutsigira vadzidzi kuwana kupinda nekugadzirisa nyaya dzekururamisira munezvezivo mudzidzo yepamusoro. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2022
- Full Text:
The nexus between territorial border controls, informal cross border trading and economic security in Zimbabwe: the case of Beitbridge Border Post
- Authors: Nare, Hilary
- Date: 2022-10-14
- Subjects: Informal sector (Economics) Zimbabwe , South Africa Commerce Zimbabwe , Border security Zimbabwe , Economic security Zimbabwe , Beitbridge (Zimbabwe) , Zimbabwe Politics and government , Zimbabwe Economic conditions
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365977 , vital:65807 , DOI https://doi.org/10.21504/10962/365977
- Description: Informal cross border trade is central to the lives of many Zimbabweans, with informal trade across the Zimbabwean-South African border being of particular importance. This entails travelling through the Beitbridge border post on the Zimbabwean side, with Zimbabwean informal traders purchasing items in South Africa for resale in Zimbabwe. In doing so, they contribute not only to their own economic security but likely to the economic security of other Zimbabweans deeply affected by the ongoing crisis in the country. Often times, when examining the lives of Zimbabwe’s informal traders, the border post is not subjected to sustained focus and analysis. Yet, border posts (like the Beitbridge border post) are complex social institutions which configure the lives and livelihoods of cross border traders in multiple ways, and which informal traders often have to negotiate their way through. In this context, this thesis provides a critical analysis of border control management at the Beitbridge border post with particular reference to the activities of Zimbabwean informal cross border traders. The Beitbridge border post, like all border posts, has multiple functions. As a territorial border post, it seeks to maintain the national sovereignty of the Zimbabwean nation- state, and it monitors and controls the movement of people and goods in both directions. Currently, it is doing so at a time when the vast majority of Zimbabweans are suffering from varying levels of economic insecurity. The extent to which these functions are performed, and the manner in which they are performed, depends fundamentally on what takes place at the Beitbridge border post. This refers to the performance of both human subjects (border control officers of various kinds) and inanimate objects (such as scanners and cameras), both of which enact agency. Combined with these is the agency of cross border traders, who are compelled to navigate their way in and through these dimensions of the border control system. The thesis examines this by drawing heavily upon Actor-Network Theory. It is based on research undertaken at Beitbridge border post, involving 50 interviews with primarily current and former border control officers as well as informal cross border traders. Findings of this study show that deficiencies in border control management and border porosity at Beitbridge have led to a flourishing of informal cross border trade and, in turn, contributed to economic security in Zimbabwe, including during the time of Covid-19. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Authors: Nare, Hilary
- Date: 2022-10-14
- Subjects: Informal sector (Economics) Zimbabwe , South Africa Commerce Zimbabwe , Border security Zimbabwe , Economic security Zimbabwe , Beitbridge (Zimbabwe) , Zimbabwe Politics and government , Zimbabwe Economic conditions
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365977 , vital:65807 , DOI https://doi.org/10.21504/10962/365977
- Description: Informal cross border trade is central to the lives of many Zimbabweans, with informal trade across the Zimbabwean-South African border being of particular importance. This entails travelling through the Beitbridge border post on the Zimbabwean side, with Zimbabwean informal traders purchasing items in South Africa for resale in Zimbabwe. In doing so, they contribute not only to their own economic security but likely to the economic security of other Zimbabweans deeply affected by the ongoing crisis in the country. Often times, when examining the lives of Zimbabwe’s informal traders, the border post is not subjected to sustained focus and analysis. Yet, border posts (like the Beitbridge border post) are complex social institutions which configure the lives and livelihoods of cross border traders in multiple ways, and which informal traders often have to negotiate their way through. In this context, this thesis provides a critical analysis of border control management at the Beitbridge border post with particular reference to the activities of Zimbabwean informal cross border traders. The Beitbridge border post, like all border posts, has multiple functions. As a territorial border post, it seeks to maintain the national sovereignty of the Zimbabwean nation- state, and it monitors and controls the movement of people and goods in both directions. Currently, it is doing so at a time when the vast majority of Zimbabweans are suffering from varying levels of economic insecurity. The extent to which these functions are performed, and the manner in which they are performed, depends fundamentally on what takes place at the Beitbridge border post. This refers to the performance of both human subjects (border control officers of various kinds) and inanimate objects (such as scanners and cameras), both of which enact agency. Combined with these is the agency of cross border traders, who are compelled to navigate their way in and through these dimensions of the border control system. The thesis examines this by drawing heavily upon Actor-Network Theory. It is based on research undertaken at Beitbridge border post, involving 50 interviews with primarily current and former border control officers as well as informal cross border traders. Findings of this study show that deficiencies in border control management and border porosity at Beitbridge have led to a flourishing of informal cross border trade and, in turn, contributed to economic security in Zimbabwe, including during the time of Covid-19. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
The role of visualisation in redefining the pedagogy of fractions in mathematics classrooms among senior primary school teachers
- Authors: Ausiku, Charity Makwiliro
- Date: 2022-10-14
- Subjects: Mathematics Study and teaching (Elementary) Namibia , Fractions Study and teaching (Elementary) Namibia , Visualization , Visual learning , Dual-coding hypothesis , Constructivism (Education) Namibia
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405456 , vital:70173 , DOI 10.21504/10962/405456
- Description: This mixed methods study explored the impact of the use of a visualisation approach on the pedagogy of eight teacher participants who were involved in the Rundu Campus Fraction Project (RCFP). The aim of this study was to determine the extent to which participants incorporated visualisation processes in the pedagogy of fractions, in view of their exposure to visualisation activities in the RCFP. Since fractions are difficult to teach and learn, visualisation was considered as an alternative approach to the pedagogy of fractions because it presents learners with opportunities to improve their proportional and spatial reasoning. This study was founded on the premise that the incorporation of both verbal and nonverbal cues can enhance the teaching and learning of fractions rather than the use of a single cue. Hence, the two theories underpinning this study are the Dual Coding Theory and the Constructivist Theory. While the Dual Coding Theory advocates for the use of verbal and nonverbal codes, the Constructivist theory states that meaningful learning occurs when learners are presented with opportunities to construct their own knowledge. Thus, the two codes are intertwined. In other words, the active construction of knowledge among learners is aided by using constructivist teaching approaches through the incorporation of both verbal and nonverbal codes. Although this study was predominantly qualitative, quantitative methods were also used in the data collection process. A questionnaire was administered to identify teacher participants for this study, based on their teaching orientations. Their views on best practices in mathematics classrooms in general and the incorporation of visualisation processes in particular, were instrumental in the selection of participants for this study. In addition, observations and semi-structured interviews were also used as research methods. Twenty-five lesson samples were video recorded, transcribed and analysed using both qualitative and quantitative methods. Moreover, each of the eight participants was exposed to a set of pre- and post-observation interviews during which they were expected to express their views on the selection, incorporation and impact of visualisation processes on the teaching of fractions. Data sets from all three instruments were analysed using both quantitative and qualitative methods. The findings indicate that the RCFP had an impact on the teaching strategies employed by the participants as they all incorporated visualisation processes into their teaching to some extent. In some lessons, the visual code was effectively blended into the verbal code while in others, the purpose of and connection between the two codes was not evident. Hence, although all the participants embraced the incorporation of visualisation in the pedagogy of mathematics, some of them struggled to find its rightful position in the teaching of fractions. The findings suggest that despite the participants’ eagerness to use visualisation in their fraction lessons, some of them did not have adequate knowledge to successfully merge it with the conventional verbal code. Thus, for the integration of visuals to be impactful, it should be carefully merged in the teaching of fractions by taking into account various factors. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Authors: Ausiku, Charity Makwiliro
- Date: 2022-10-14
- Subjects: Mathematics Study and teaching (Elementary) Namibia , Fractions Study and teaching (Elementary) Namibia , Visualization , Visual learning , Dual-coding hypothesis , Constructivism (Education) Namibia
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405456 , vital:70173 , DOI 10.21504/10962/405456
- Description: This mixed methods study explored the impact of the use of a visualisation approach on the pedagogy of eight teacher participants who were involved in the Rundu Campus Fraction Project (RCFP). The aim of this study was to determine the extent to which participants incorporated visualisation processes in the pedagogy of fractions, in view of their exposure to visualisation activities in the RCFP. Since fractions are difficult to teach and learn, visualisation was considered as an alternative approach to the pedagogy of fractions because it presents learners with opportunities to improve their proportional and spatial reasoning. This study was founded on the premise that the incorporation of both verbal and nonverbal cues can enhance the teaching and learning of fractions rather than the use of a single cue. Hence, the two theories underpinning this study are the Dual Coding Theory and the Constructivist Theory. While the Dual Coding Theory advocates for the use of verbal and nonverbal codes, the Constructivist theory states that meaningful learning occurs when learners are presented with opportunities to construct their own knowledge. Thus, the two codes are intertwined. In other words, the active construction of knowledge among learners is aided by using constructivist teaching approaches through the incorporation of both verbal and nonverbal codes. Although this study was predominantly qualitative, quantitative methods were also used in the data collection process. A questionnaire was administered to identify teacher participants for this study, based on their teaching orientations. Their views on best practices in mathematics classrooms in general and the incorporation of visualisation processes in particular, were instrumental in the selection of participants for this study. In addition, observations and semi-structured interviews were also used as research methods. Twenty-five lesson samples were video recorded, transcribed and analysed using both qualitative and quantitative methods. Moreover, each of the eight participants was exposed to a set of pre- and post-observation interviews during which they were expected to express their views on the selection, incorporation and impact of visualisation processes on the teaching of fractions. Data sets from all three instruments were analysed using both quantitative and qualitative methods. The findings indicate that the RCFP had an impact on the teaching strategies employed by the participants as they all incorporated visualisation processes into their teaching to some extent. In some lessons, the visual code was effectively blended into the verbal code while in others, the purpose of and connection between the two codes was not evident. Hence, although all the participants embraced the incorporation of visualisation in the pedagogy of mathematics, some of them struggled to find its rightful position in the teaching of fractions. The findings suggest that despite the participants’ eagerness to use visualisation in their fraction lessons, some of them did not have adequate knowledge to successfully merge it with the conventional verbal code. Thus, for the integration of visuals to be impactful, it should be carefully merged in the teaching of fractions by taking into account various factors. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
The uptake of educational technology in South African Higher Education: a study of the context that conditioned emergency remote teaching in the pandemic
- Ngcobo, Nomathemba Faustinah
- Authors: Ngcobo, Nomathemba Faustinah
- Date: 2022-10-14
- Subjects: Educational technology South Africa , Education, Higher South Africa , Academic development , COVID-19 Pandemic, 2020- South Africa , Distance education Computer-assisted instruction , Web-based instruction South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405495 , vital:70176 , DOI 10.21504/10962/405495
- Description: The study explores the enablements and constraints in the uptake of educational technologies in the South African higher education system. This is a multiple institutional study which considers the differentiated nature of higher education institutions in South Africa and reflects on the implications of this for the use of educational technology (EdTech). EdTech is seen as an important aspect of 21st century education. As an established practice in many universities it has made a significant impact on teaching and learning practices. However, EdTech is often presented as a panacea to educational problems and implemented without consideration of the contexts in which it is used. Data was collected from the educational technology units of 22 of the 26 public higher education institutions and the main sources of this data were an online survey questionnaire related to the uptake of educational technologies and semi-structured interviews. For the research analysis, Archer’s analytical dualism and morphogenetic cycle provided a framework with the understanding that a social phenomenon such as EdTech emerges from a complex interplay of multiple mechanisms rather than through simple unidirectional causality. The framework directed me to analyse structure, culture and agency as separate entities allowing an understanding of the complex and rapidly growing phenomenon of EdTech. Analytical dualism provides guiding principles on how agential actions, structural resources, and cultural practices emerge and allows an understanding of how agents experience and respond to structures and cultures in social fields, for example, the uptake of EdTech for teaching and learning. The morphogenetic cycle reveals the historical nature the EdTech uptake with events happening over a period of time so that past events, which possess structural and cultural mechanisms, condition agency in socio-cultural interaction. The study identified several mechanisms enabling and constraining the uptake of EdTech, and while the findings are not exhaustive, they do indicate important enablements and constraints which the sector would do well to consider as it enters a post-pandemic phase. The data was collected prior to the pandemic and thus provides an understanding of what allowed for the uptake of EdTech when face-to-face teaching and learning was the norm. While the pandemic resulted in a rapid pivot to Emergency Remote Teaching (ERT), and fundamentally changed the face of EdTech in the South African higher education sector and around the world, the findings of this study remain pertinent. Archer argues that when a new person or structure is introduced, it occurs within a pre-existing context and so what emerges should not be seen to be simply caused by that new person or structure. Rather, its emergent properties are exercised within the conditioning effects of the pre-existing structures, cultures and agents. The Covid-19 virus brought about significant effects around the world, but it would be a mistake for us to assume that the effects were the same across different national higher education systems or even across different universities within a country. For us to understand both what occurred during the pivot to ERT and to consider the implications of this for the future of EdTech, it is imperative that we understand the pre-existing conditions in which ERT was implemented. This thesis offers a rich picture of these pre-existing conditions. Key findings include the extreme extent to which universities differed in their resourcing and uptake of EdTech prior to the pandemic. In some universities, there were well-resourced EdTech centres while in others, the implementation of EdTech was seen to be the responsibility of the IT department. Even where EdTech staff were employed, the nature of this employment varied greatly. In some cases, such staff were seen as educational experts who were hired as academics and often worked within academic development centres. In other cases, such staff were employed as administrative support staff. Another difference pertained to whether they were employed on contract (often funded through project funding) or on a permanent basis. These differences in employment and the positioning of the EdTech staff were seen to greatly condition the levels of credibility they enjoyed and the kinds of work they could undertake. If they were employed as support staff, they were more likely to be seen to be responsible for providing academics with end-user technical assistance. If they were employed as academics, they were more likely to be seen to be responsible for providing pedagogical and curriculum development support in using EdTech for teaching and learning. Another set of findings related to the extent to which EdTech was seen to be valued within each university, such as by being included in promotions criteria, mentioned in institutional strategies, and supported by university management. Where this was not the case, this constrained the uptake of EdTech. In all cases, the EdTech staff reported working almost exclusively with academics who sought to develop their EdTech capability on a voluntary basis because it aligned to what Archer terms their ‘personal projects’. At times a departmental champion, especially in the form of the Head of Department as a social actor, led to EdTech uptake spreading across the academic body. There was evidence of some resistance to the use of EdTech and a great deal of anxiety among some academics. This was seen to be implicated in concerns that at times EdTech was seen to be a ‘dumping ground’ and the Learning Management System positioned simply as a repository of materials. Many academics reported being pushed by their students to integrate more technology in their teaching. Many students seem to be adept at using technology and can see its potential pedagogical benefits and so placed pressure for this to be increased. There were however concerns that the notion of ‘Digital Natives’, that is millennial students who were born into a technological era, was only a partial picture of the student body. The ‘Digital Divide’ meant that there was highly uneven access to hardware, data, bandwidth, and technological literacies among the student body. For many students, their only access to technology was while they were physically on campus, a finding that was to have extreme implications for the pivot to ERT. This research will be valuable to the field of educational technology and enhance the understanding of what is needed to enable the uptake of educational technologies in higher education teaching and learning in pedagogically sound ways. As the sector responds to the pandemic and reflects on lessons learned during this time, it will be important to look to the conditions outlined in this study as they continue to enable and constrain the uptake of educational technology. , Ucwaningo olwethulwe yindlela elandela imigomo ka-Bhaskar kanye no-Archer yesayensi yezenhlalo ehlola ukuze inikeze incazelo yokuvumeleka nezithiyo ekuthathweni kwezifundo ezisekwe ubuchwepheshe besimanje. Lolu ucwaningo lwezikhungo eziningi zemfundo ephakeme, futhi inhloso yalo enkulu bekuwukuhlonza ukuthi kwavela kanjani izindlela ezehlukene ukuze kuvunyelwe futhi kuvinjwe ukusetshenziswa kobuchwepheshe bezemfundo ezikhungweni zemfundo ephakeme ezehlukene eNingizimu Afrika. Izifundo ezisekwe ubuchwepheshe besimanje (EdTechs) ibonwa njengezici ezibalulekile zemfundo yekhulu lamashumi amabili nanye (21st century), futhi njengomkhuba osunguliwe emanyuvesi ibe nomthelela omkhulu ekufundiseni nasekufundeni. Kodwa-ke, i-EdTechs ivame ukwethulwa njengekhambi ezinkingeni zemfundo futhi yacwaningwa ngaphandle kokucabangela izimo lapho isetshenziswa khona. Ngenxa yalokho, kwaba nesidingo sokuqonda kangcono ukuthi ukutholwa kwayo kwehlukaniswa kanjani phakathi nohlelo lwemfundo ephakeme olungalingani emaNyuvesi ahlukene. Ubufakazi buqoqwe ezingxenyeni zobuchwepheshe bezemfundo zezikhungo zemfundo ephakeme zikahulumeni ezingamashumi amabili nambili (22) kwezingamashumi amabili nesithupha (26) futhi imithombo eyinhloko yalobufakazi kwakuwuhlu lwemibuzo lwenhlolovo oluku-inthanethi oluhlobene nokusetshenziswa kobuchwepheshe bezemfundo kwase kulandela kanye nezingxoxiswano ezihlelwe kancane. Ukuze kuhlaziywe ucwaningo, i-analytical dualism ngokuka-Archer kanye nomjikelezo we-morphogenetic (uzalo kabusha) unikeze uhlaka lokuhlaziywa kokutholwa kobuchwepheshe bezemfundo njengokusebenzelana okuqhubekayo phakathi kwezifundiswa nabasebenzi bomnyango bobuchwepheshe besimanje (EdTech staff). Ekuhlaziyeni, ngixoxa ngokuthi uhlaka lungiqondise kanjani ukuba ngihlaziye isakhiwo, isiko kanye nokwenza kwabantu njengezinhlangano ezihlukene nokuthi kungani lolu hlaka lufaneleka ukuze siqonde lesi simo esiyinkimbinkimbi nesikhula ngokushesha sezemfundo zobuchwepheshe besimanje. Ubumbaxambili bokuhlaziya buhlinzeka ngohlaka oluvumela abacwaningi ezimweni zomphakathi ukuthi babone futhi bahlaziye izindlela ezikhiqizayo neziyisisekelo, okuhlanganisa izindlela zokwenza ngokusebenzisa ukuxhumana komphakathi. Iphinde inikeze izimiso eziqondisayo zokuthi ezinye izenzo zokwenza komuntu kanye nemikhuba yamasiko zivela kanjani kanye nokuqonda ukuthi abenzi nabasebenzi bezemfundo, nokuthi abhekana kanjani futhi asabela kanjani ezakhiweni namasiko emikhakheni yezenhlalo, isibonelo, ukutholwa kwe-EdTechs ekufundiseni nokufunda. Ngaphezu kwalokho, umjikelezo we-morphogenetic wembula ubunjalo bomlando ukuthathwa kwe-EdTechs nezenzakalo ezenzeka esikhathini esithile ukuze izehlakalo ezidlule ezinezindlela zesakhiwo nezamasiko zibekezelele izenzo zezifundiswa njenge-ejensi ezovela ekusebenzelaneni kwezenhlalo namasiko. Izakhiwo ezivelayo zesakhiwo, isiko kanye nezabenzi zibonwa njengezindlela ezibalulekile ezivumela futhi zibambe iqhaza ekuthathweni kobuchwepheshe bezemfundo ekufundiseni nokufunda yizifundiswa. Ngakho-ke, ucwaningo luveza ukuthi kungani ukuthathwa kunezindlela ezivumelayo neziphoqayo futhi ukuxhumana phakathi kwesakhiwo, isiko kanye nomenzi kudala ukucabangela kwesimo okungaba okuncomayo noma okuphikisanayo ngokwemvelo. Imvume yokulandelana kwesimo yencazelo yokuthi kungani kunokuhlangenwe nakho okuhlukile ekuthathweni kwalawa ma-EdTech avela ezikhungweni ezehlukene esimweni semfundo ephakeme yaseNingizimu Afrika. Lolu cwaningo luzobaluleka emkhakheni wezobuchwepheshe bezemfundo futhi luthuthukise ukuqonda kwalokho okudingekayo ukuze kusetshenziswe ubuchwepheshe bezemfundo ekufundiseni nasekufundeni imfundo ephakeme. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2022
- Full Text:
- Authors: Ngcobo, Nomathemba Faustinah
- Date: 2022-10-14
- Subjects: Educational technology South Africa , Education, Higher South Africa , Academic development , COVID-19 Pandemic, 2020- South Africa , Distance education Computer-assisted instruction , Web-based instruction South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/405495 , vital:70176 , DOI 10.21504/10962/405495
- Description: The study explores the enablements and constraints in the uptake of educational technologies in the South African higher education system. This is a multiple institutional study which considers the differentiated nature of higher education institutions in South Africa and reflects on the implications of this for the use of educational technology (EdTech). EdTech is seen as an important aspect of 21st century education. As an established practice in many universities it has made a significant impact on teaching and learning practices. However, EdTech is often presented as a panacea to educational problems and implemented without consideration of the contexts in which it is used. Data was collected from the educational technology units of 22 of the 26 public higher education institutions and the main sources of this data were an online survey questionnaire related to the uptake of educational technologies and semi-structured interviews. For the research analysis, Archer’s analytical dualism and morphogenetic cycle provided a framework with the understanding that a social phenomenon such as EdTech emerges from a complex interplay of multiple mechanisms rather than through simple unidirectional causality. The framework directed me to analyse structure, culture and agency as separate entities allowing an understanding of the complex and rapidly growing phenomenon of EdTech. Analytical dualism provides guiding principles on how agential actions, structural resources, and cultural practices emerge and allows an understanding of how agents experience and respond to structures and cultures in social fields, for example, the uptake of EdTech for teaching and learning. The morphogenetic cycle reveals the historical nature the EdTech uptake with events happening over a period of time so that past events, which possess structural and cultural mechanisms, condition agency in socio-cultural interaction. The study identified several mechanisms enabling and constraining the uptake of EdTech, and while the findings are not exhaustive, they do indicate important enablements and constraints which the sector would do well to consider as it enters a post-pandemic phase. The data was collected prior to the pandemic and thus provides an understanding of what allowed for the uptake of EdTech when face-to-face teaching and learning was the norm. While the pandemic resulted in a rapid pivot to Emergency Remote Teaching (ERT), and fundamentally changed the face of EdTech in the South African higher education sector and around the world, the findings of this study remain pertinent. Archer argues that when a new person or structure is introduced, it occurs within a pre-existing context and so what emerges should not be seen to be simply caused by that new person or structure. Rather, its emergent properties are exercised within the conditioning effects of the pre-existing structures, cultures and agents. The Covid-19 virus brought about significant effects around the world, but it would be a mistake for us to assume that the effects were the same across different national higher education systems or even across different universities within a country. For us to understand both what occurred during the pivot to ERT and to consider the implications of this for the future of EdTech, it is imperative that we understand the pre-existing conditions in which ERT was implemented. This thesis offers a rich picture of these pre-existing conditions. Key findings include the extreme extent to which universities differed in their resourcing and uptake of EdTech prior to the pandemic. In some universities, there were well-resourced EdTech centres while in others, the implementation of EdTech was seen to be the responsibility of the IT department. Even where EdTech staff were employed, the nature of this employment varied greatly. In some cases, such staff were seen as educational experts who were hired as academics and often worked within academic development centres. In other cases, such staff were employed as administrative support staff. Another difference pertained to whether they were employed on contract (often funded through project funding) or on a permanent basis. These differences in employment and the positioning of the EdTech staff were seen to greatly condition the levels of credibility they enjoyed and the kinds of work they could undertake. If they were employed as support staff, they were more likely to be seen to be responsible for providing academics with end-user technical assistance. If they were employed as academics, they were more likely to be seen to be responsible for providing pedagogical and curriculum development support in using EdTech for teaching and learning. Another set of findings related to the extent to which EdTech was seen to be valued within each university, such as by being included in promotions criteria, mentioned in institutional strategies, and supported by university management. Where this was not the case, this constrained the uptake of EdTech. In all cases, the EdTech staff reported working almost exclusively with academics who sought to develop their EdTech capability on a voluntary basis because it aligned to what Archer terms their ‘personal projects’. At times a departmental champion, especially in the form of the Head of Department as a social actor, led to EdTech uptake spreading across the academic body. There was evidence of some resistance to the use of EdTech and a great deal of anxiety among some academics. This was seen to be implicated in concerns that at times EdTech was seen to be a ‘dumping ground’ and the Learning Management System positioned simply as a repository of materials. Many academics reported being pushed by their students to integrate more technology in their teaching. Many students seem to be adept at using technology and can see its potential pedagogical benefits and so placed pressure for this to be increased. There were however concerns that the notion of ‘Digital Natives’, that is millennial students who were born into a technological era, was only a partial picture of the student body. The ‘Digital Divide’ meant that there was highly uneven access to hardware, data, bandwidth, and technological literacies among the student body. For many students, their only access to technology was while they were physically on campus, a finding that was to have extreme implications for the pivot to ERT. This research will be valuable to the field of educational technology and enhance the understanding of what is needed to enable the uptake of educational technologies in higher education teaching and learning in pedagogically sound ways. As the sector responds to the pandemic and reflects on lessons learned during this time, it will be important to look to the conditions outlined in this study as they continue to enable and constrain the uptake of educational technology. , Ucwaningo olwethulwe yindlela elandela imigomo ka-Bhaskar kanye no-Archer yesayensi yezenhlalo ehlola ukuze inikeze incazelo yokuvumeleka nezithiyo ekuthathweni kwezifundo ezisekwe ubuchwepheshe besimanje. Lolu ucwaningo lwezikhungo eziningi zemfundo ephakeme, futhi inhloso yalo enkulu bekuwukuhlonza ukuthi kwavela kanjani izindlela ezehlukene ukuze kuvunyelwe futhi kuvinjwe ukusetshenziswa kobuchwepheshe bezemfundo ezikhungweni zemfundo ephakeme ezehlukene eNingizimu Afrika. Izifundo ezisekwe ubuchwepheshe besimanje (EdTechs) ibonwa njengezici ezibalulekile zemfundo yekhulu lamashumi amabili nanye (21st century), futhi njengomkhuba osunguliwe emanyuvesi ibe nomthelela omkhulu ekufundiseni nasekufundeni. Kodwa-ke, i-EdTechs ivame ukwethulwa njengekhambi ezinkingeni zemfundo futhi yacwaningwa ngaphandle kokucabangela izimo lapho isetshenziswa khona. Ngenxa yalokho, kwaba nesidingo sokuqonda kangcono ukuthi ukutholwa kwayo kwehlukaniswa kanjani phakathi nohlelo lwemfundo ephakeme olungalingani emaNyuvesi ahlukene. Ubufakazi buqoqwe ezingxenyeni zobuchwepheshe bezemfundo zezikhungo zemfundo ephakeme zikahulumeni ezingamashumi amabili nambili (22) kwezingamashumi amabili nesithupha (26) futhi imithombo eyinhloko yalobufakazi kwakuwuhlu lwemibuzo lwenhlolovo oluku-inthanethi oluhlobene nokusetshenziswa kobuchwepheshe bezemfundo kwase kulandela kanye nezingxoxiswano ezihlelwe kancane. Ukuze kuhlaziywe ucwaningo, i-analytical dualism ngokuka-Archer kanye nomjikelezo we-morphogenetic (uzalo kabusha) unikeze uhlaka lokuhlaziywa kokutholwa kobuchwepheshe bezemfundo njengokusebenzelana okuqhubekayo phakathi kwezifundiswa nabasebenzi bomnyango bobuchwepheshe besimanje (EdTech staff). Ekuhlaziyeni, ngixoxa ngokuthi uhlaka lungiqondise kanjani ukuba ngihlaziye isakhiwo, isiko kanye nokwenza kwabantu njengezinhlangano ezihlukene nokuthi kungani lolu hlaka lufaneleka ukuze siqonde lesi simo esiyinkimbinkimbi nesikhula ngokushesha sezemfundo zobuchwepheshe besimanje. Ubumbaxambili bokuhlaziya buhlinzeka ngohlaka oluvumela abacwaningi ezimweni zomphakathi ukuthi babone futhi bahlaziye izindlela ezikhiqizayo neziyisisekelo, okuhlanganisa izindlela zokwenza ngokusebenzisa ukuxhumana komphakathi. Iphinde inikeze izimiso eziqondisayo zokuthi ezinye izenzo zokwenza komuntu kanye nemikhuba yamasiko zivela kanjani kanye nokuqonda ukuthi abenzi nabasebenzi bezemfundo, nokuthi abhekana kanjani futhi asabela kanjani ezakhiweni namasiko emikhakheni yezenhlalo, isibonelo, ukutholwa kwe-EdTechs ekufundiseni nokufunda. Ngaphezu kwalokho, umjikelezo we-morphogenetic wembula ubunjalo bomlando ukuthathwa kwe-EdTechs nezenzakalo ezenzeka esikhathini esithile ukuze izehlakalo ezidlule ezinezindlela zesakhiwo nezamasiko zibekezelele izenzo zezifundiswa njenge-ejensi ezovela ekusebenzelaneni kwezenhlalo namasiko. Izakhiwo ezivelayo zesakhiwo, isiko kanye nezabenzi zibonwa njengezindlela ezibalulekile ezivumela futhi zibambe iqhaza ekuthathweni kobuchwepheshe bezemfundo ekufundiseni nokufunda yizifundiswa. Ngakho-ke, ucwaningo luveza ukuthi kungani ukuthathwa kunezindlela ezivumelayo neziphoqayo futhi ukuxhumana phakathi kwesakhiwo, isiko kanye nomenzi kudala ukucabangela kwesimo okungaba okuncomayo noma okuphikisanayo ngokwemvelo. Imvume yokulandelana kwesimo yencazelo yokuthi kungani kunokuhlangenwe nakho okuhlukile ekuthathweni kwalawa ma-EdTech avela ezikhungweni ezehlukene esimweni semfundo ephakeme yaseNingizimu Afrika. Lolu cwaningo luzobaluleka emkhakheni wezobuchwepheshe bezemfundo futhi luthuthukise ukuqonda kwalokho okudingekayo ukuze kusetshenziswe ubuchwepheshe bezemfundo ekufundiseni nasekufundeni imfundo ephakeme. , Thesis (PhD) -- Faculty of Education, Centre for Higher Education Research, Teaching and Learning, 2022
- Full Text:
Understanding resource partitioning in three species of Gobiidae living in the warm-temperate Sundays Estuary
- Authors: Ndaleni, Phumza Malibongwe
- Date: 2022-10-14
- Subjects: Gobiidae South Africa Sundays Estuary (Eastern Cape) , Gobiidae Reproduction , Gobiidae Food , Gobiidae Geographical distribution , Gobiidae Morphology , Resource partitioning (Ecology)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365655 , vital:65773 , DOI https://doi.org/10.21504/10962/365655
- Description: Estuaries represent a transition zone where saline water combines with freshwater, and this results in temporal and spatial variability in both biotic and abiotic parameters. Because the environmental gradient changes so rapidly in areas and the estuarine environment is harsh, fish need to either be able to specialise to one particular suite of abiotic contexts or have the physiological mechanisms to allow them to move throughout the gradient of the estuary. Apart from this, other factors such as climate change, habitat degradation, over exploitation of resources and the introduction of alien species also negatively influence fish species living in estuaries. These anthropogenic stressors can cause species exclusion in areas which were previously suitable for species with particular suites of traits. Measuring resource partitioning within functional groups not only helps in determining the functional structure of communities but also explains how organisms use resources in a community. Resource partitioning studies provide a useful conceptual framework to understand species interactions in a community and identify major resource dimensions along which species segregate. This study aimed to describe resource partitioning among the Gobiidae species, as the family is well represented in South African estuaries (24 species), is highly abundant and has several species which co-exist in individual estuaries. To accomplish this, different forms of resource partitioning that promote the coexistence of the three most abundant species found in warm-temperate South African estuaries; the Knysna sand goby Psammogobius knysnaensis (Smith, 1935), Prison goby Caffrogobius gilchristi (Boulenger, 1898) and River goby Glossogobius callidus (Smith, 1937) were investigated in the Sundays Estuary. This was accomplished by determining the reproductive biology, interspecific differences in feeding morphology, feeding ecology and habitat partitioning among the three species. The distribution and abundance of potential prey in the estuary (mesozooplankton and macrozoobenthic communities) were investigated, with both mesozooplankton and macrozoobenthic communities grouping into three distinct communities along the environmental gradient. Feeding morphological traits responsible for prey location, chasing, capture, mastication, ingestion and digestion were investigated. Little morphological overlap was observed between P. knysnaensis and C. gilchristi, indicating little dietary overlap between these two species. In contrast, the feeding morphology of Glossogobius callidus overlapped with both P. knysnaensis and C. gilchristi, indicating the potential to compete with both species for food. The trophic ecology of the three species was investigated using stomach content analysis, whereby prey abundance, frequency of occurrence and percentage of volume were determined. For P. knysnaensis, the incorporation of cyclopoids and ostracods decreased with fish size and that of bivalves and amphipods increased. Caffrogobius gilchristi was found to be a specialist feeder on cyclopoids but as the species increased in size the incorporation of amphipods, mysids, brachyurans and gastropods increased. Glossogobius callidus was found to be a generalist feeder, feeding on cyclopoids, amphipods and chironomids. The incorporation of cyclopoids decreased with fish size and the consumption of large sized amphipods and chironomids increased with fish size. To assess their reproductive biology, gonadosomatic index (GSI) was used to study the breeding season. In all three species, reproduction peaked in spring and summer, and this is associated with peak phytoplankton and zooplankton biomass in estuaries. Length at 50% maturity and fecundity were also determined. The three species predominated in different locations in the estuary, which explains why they were able to use similar resources and reproduce at the same time. Psammogobius knysnaensis was abundant in the sandy mouth region, with sediment type and prey (bivalves and mysids) availability affecting its distribution. Caffrogobius gilchristi was abundant in the muddy lower reaches of the estuary, with its distribution influenced by sediment composition and temperature. Glossogobius callidus was abundant in the turbid upper reaches, with its distribution influenced by prey (amphipods) availability and turbidity. Different habitat preferences and diet among the specific size ranges enabled coexistence among the species. This explains the high abundances and coexistence of gobies in South African estuaries. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Authors: Ndaleni, Phumza Malibongwe
- Date: 2022-10-14
- Subjects: Gobiidae South Africa Sundays Estuary (Eastern Cape) , Gobiidae Reproduction , Gobiidae Food , Gobiidae Geographical distribution , Gobiidae Morphology , Resource partitioning (Ecology)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365655 , vital:65773 , DOI https://doi.org/10.21504/10962/365655
- Description: Estuaries represent a transition zone where saline water combines with freshwater, and this results in temporal and spatial variability in both biotic and abiotic parameters. Because the environmental gradient changes so rapidly in areas and the estuarine environment is harsh, fish need to either be able to specialise to one particular suite of abiotic contexts or have the physiological mechanisms to allow them to move throughout the gradient of the estuary. Apart from this, other factors such as climate change, habitat degradation, over exploitation of resources and the introduction of alien species also negatively influence fish species living in estuaries. These anthropogenic stressors can cause species exclusion in areas which were previously suitable for species with particular suites of traits. Measuring resource partitioning within functional groups not only helps in determining the functional structure of communities but also explains how organisms use resources in a community. Resource partitioning studies provide a useful conceptual framework to understand species interactions in a community and identify major resource dimensions along which species segregate. This study aimed to describe resource partitioning among the Gobiidae species, as the family is well represented in South African estuaries (24 species), is highly abundant and has several species which co-exist in individual estuaries. To accomplish this, different forms of resource partitioning that promote the coexistence of the three most abundant species found in warm-temperate South African estuaries; the Knysna sand goby Psammogobius knysnaensis (Smith, 1935), Prison goby Caffrogobius gilchristi (Boulenger, 1898) and River goby Glossogobius callidus (Smith, 1937) were investigated in the Sundays Estuary. This was accomplished by determining the reproductive biology, interspecific differences in feeding morphology, feeding ecology and habitat partitioning among the three species. The distribution and abundance of potential prey in the estuary (mesozooplankton and macrozoobenthic communities) were investigated, with both mesozooplankton and macrozoobenthic communities grouping into three distinct communities along the environmental gradient. Feeding morphological traits responsible for prey location, chasing, capture, mastication, ingestion and digestion were investigated. Little morphological overlap was observed between P. knysnaensis and C. gilchristi, indicating little dietary overlap between these two species. In contrast, the feeding morphology of Glossogobius callidus overlapped with both P. knysnaensis and C. gilchristi, indicating the potential to compete with both species for food. The trophic ecology of the three species was investigated using stomach content analysis, whereby prey abundance, frequency of occurrence and percentage of volume were determined. For P. knysnaensis, the incorporation of cyclopoids and ostracods decreased with fish size and that of bivalves and amphipods increased. Caffrogobius gilchristi was found to be a specialist feeder on cyclopoids but as the species increased in size the incorporation of amphipods, mysids, brachyurans and gastropods increased. Glossogobius callidus was found to be a generalist feeder, feeding on cyclopoids, amphipods and chironomids. The incorporation of cyclopoids decreased with fish size and the consumption of large sized amphipods and chironomids increased with fish size. To assess their reproductive biology, gonadosomatic index (GSI) was used to study the breeding season. In all three species, reproduction peaked in spring and summer, and this is associated with peak phytoplankton and zooplankton biomass in estuaries. Length at 50% maturity and fecundity were also determined. The three species predominated in different locations in the estuary, which explains why they were able to use similar resources and reproduce at the same time. Psammogobius knysnaensis was abundant in the sandy mouth region, with sediment type and prey (bivalves and mysids) availability affecting its distribution. Caffrogobius gilchristi was abundant in the muddy lower reaches of the estuary, with its distribution influenced by sediment composition and temperature. Glossogobius callidus was abundant in the turbid upper reaches, with its distribution influenced by prey (amphipods) availability and turbidity. Different habitat preferences and diet among the specific size ranges enabled coexistence among the species. This explains the high abundances and coexistence of gobies in South African estuaries. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
Youth, political violence and ZANU-PF politics in Zimbabwe, c.1950-2018
- Authors: Munyarari, Tinashe
- Date: 2022-10-14
- Subjects: Youth protest movements Zimbabwe , Political violence Zimbabwe , ZANU-PF (Organization : Zimbabwe) , Agent (Philosophy) , Zimbabwe Politics and government , Zimbabwe History
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365966 , vital:65806 , DOI https://doi.org/10.21504/10962/365966
- Description: This study is a socio-political aspect of Zimbabwean history. It examines the development of youth political violence starting from the late 1950s when violent forms of African political mobilisation emerged to 2018 when the first election without Robert Mugabe was held. It explores how early nationalist parties such as the Salisbury City Youth League (SCYL), Southern Rhodesia African National Congress (SRANC), National Democratic Party (NDP), Zimbabwe African People’s Union (ZAPU) and later the Zimbabwe African National Union (ZANU) mobilised and socialised youths into political violence to understand the roots of the violent political culture in Zimbabwe. This study shows that youths were an important part of the strategies of these political parties in countering the violence of the colonial state as well as mobilising mass support for the movements during the liberation struggle. It reveals that war collaborators (mujibhas and chimbwidos) were central role players in instigating political violence against innocent and defenceless people during the war. In the 1980s and 1990s, the Youth brigades and the ZANU-PF Youth League became a key constituent for state-socialist developmental goals but they were at times manipulated as a resource for political violence when Mugabe’s power was challenged. The study shows that more grotesque violence occurred in the 2000s era when the National Youth Service (NYS) was introduced and state-sanctioned vigilante groups like Chipangano in Mbare emerged in response to the rise of the Movement for Democratic Change (MDC) and diminishing of consensual power. This study argues that youth were not mere victims and perpetrators of political violence, but they were a collection of various interest sub-groups with diverse agendas and a sense of agency. Some joined violent groups for their social mobility, power, impunity and economic opportunities availed to the group members. Data for this study was drawn from Mbare and Highfields (in Harare Province) and Uzumba-Maramba-Pfungwe (in Mashonaland East Province). , Thesis (PhD) -- Faculty of Humanities, History, 2022
- Full Text:
- Authors: Munyarari, Tinashe
- Date: 2022-10-14
- Subjects: Youth protest movements Zimbabwe , Political violence Zimbabwe , ZANU-PF (Organization : Zimbabwe) , Agent (Philosophy) , Zimbabwe Politics and government , Zimbabwe History
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365966 , vital:65806 , DOI https://doi.org/10.21504/10962/365966
- Description: This study is a socio-political aspect of Zimbabwean history. It examines the development of youth political violence starting from the late 1950s when violent forms of African political mobilisation emerged to 2018 when the first election without Robert Mugabe was held. It explores how early nationalist parties such as the Salisbury City Youth League (SCYL), Southern Rhodesia African National Congress (SRANC), National Democratic Party (NDP), Zimbabwe African People’s Union (ZAPU) and later the Zimbabwe African National Union (ZANU) mobilised and socialised youths into political violence to understand the roots of the violent political culture in Zimbabwe. This study shows that youths were an important part of the strategies of these political parties in countering the violence of the colonial state as well as mobilising mass support for the movements during the liberation struggle. It reveals that war collaborators (mujibhas and chimbwidos) were central role players in instigating political violence against innocent and defenceless people during the war. In the 1980s and 1990s, the Youth brigades and the ZANU-PF Youth League became a key constituent for state-socialist developmental goals but they were at times manipulated as a resource for political violence when Mugabe’s power was challenged. The study shows that more grotesque violence occurred in the 2000s era when the National Youth Service (NYS) was introduced and state-sanctioned vigilante groups like Chipangano in Mbare emerged in response to the rise of the Movement for Democratic Change (MDC) and diminishing of consensual power. This study argues that youth were not mere victims and perpetrators of political violence, but they were a collection of various interest sub-groups with diverse agendas and a sense of agency. Some joined violent groups for their social mobility, power, impunity and economic opportunities availed to the group members. Data for this study was drawn from Mbare and Highfields (in Harare Province) and Uzumba-Maramba-Pfungwe (in Mashonaland East Province). , Thesis (PhD) -- Faculty of Humanities, History, 2022
- Full Text:
An examination of activism and ‘political listening’ during the year of student protest at the University of Cape Town from 9 March 2015 to 9 March 2016
- Mufamadi, Azwihangwisi Eugene
- Authors: Mufamadi, Azwihangwisi Eugene
- Date: 2022-10-04
- Subjects: Student movements South Africa Cape Town , Democracy South Africa , Listening Political aspects , Journalistic ethics , Journalism Political aspects , Communication in social action South Africa Cape Town , University of Cape Town , Cape Times Ltd.
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327144 , vital:61085 , DOI 10.21504/10962/327144
- Description: This study sets out to examine democratic participation in South Africa and the role that ‘political listening’ could play in making participation more equitable. It considers protest action on a South African university campus, which at times not only resulted in significant and swift concessions from the university leadership but also sparked national political action which got an equally swift response from the South African government. It considers the social movement, the RhodesMustFall movement (RMF), as one way in which students can organise themselves to get a better hearing from the University of Cape Town (UCT) management in their attempt to make a meaningful contribution to the university’s micro democracy. This study examines whether the interaction between the UCT management and RMF could be considered ‘political listening’, and the possible role of the Cape Times newspaper within this context of participation. Using data gathered through interviews, written communications, observation and newspaper articles, the study shows that in all of the interactions between RMF and the UCT management, both groups were seldom willing to forego their power to engage in genuine listening. Instead, the two parties guessed at what power the other party might have and acted to reduce that power. It is in this context of guessing at and figuring what power the other party has that listening occurs. Furthermore, the study shows that during the RMF protest, the UCT management viewed their responsibility for the institution mainly through the lens of Private Property Law which framed protest as something to be dealt with by restoring law and order. The study also details the role of the Cape Times newspaper in the interactions between RMF and the UCT management and considers if this role could be political listening. The study is exploratory and demonstrates how political listening could work more optimally in real-life instances. , Thesis (PhD) -- Faculty of Humanities, Journalism and Media Studies, 2022
- Full Text:
- Authors: Mufamadi, Azwihangwisi Eugene
- Date: 2022-10-04
- Subjects: Student movements South Africa Cape Town , Democracy South Africa , Listening Political aspects , Journalistic ethics , Journalism Political aspects , Communication in social action South Africa Cape Town , University of Cape Town , Cape Times Ltd.
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327144 , vital:61085 , DOI 10.21504/10962/327144
- Description: This study sets out to examine democratic participation in South Africa and the role that ‘political listening’ could play in making participation more equitable. It considers protest action on a South African university campus, which at times not only resulted in significant and swift concessions from the university leadership but also sparked national political action which got an equally swift response from the South African government. It considers the social movement, the RhodesMustFall movement (RMF), as one way in which students can organise themselves to get a better hearing from the University of Cape Town (UCT) management in their attempt to make a meaningful contribution to the university’s micro democracy. This study examines whether the interaction between the UCT management and RMF could be considered ‘political listening’, and the possible role of the Cape Times newspaper within this context of participation. Using data gathered through interviews, written communications, observation and newspaper articles, the study shows that in all of the interactions between RMF and the UCT management, both groups were seldom willing to forego their power to engage in genuine listening. Instead, the two parties guessed at what power the other party might have and acted to reduce that power. It is in this context of guessing at and figuring what power the other party has that listening occurs. Furthermore, the study shows that during the RMF protest, the UCT management viewed their responsibility for the institution mainly through the lens of Private Property Law which framed protest as something to be dealt with by restoring law and order. The study also details the role of the Cape Times newspaper in the interactions between RMF and the UCT management and considers if this role could be political listening. The study is exploratory and demonstrates how political listening could work more optimally in real-life instances. , Thesis (PhD) -- Faculty of Humanities, Journalism and Media Studies, 2022
- Full Text:
Exploring the value of an educational partnership within a multilingual pre-school setting
- Authors: Maritz, Anneliese
- Date: 2022-10-04
- Subjects: Early childhood education Parent participation South Africa Eastern Cape , Early childhood teachers Training of , Home and school South Africa Eastern Cape , Parent-teacher relationships South Africa Eastern Cape , Communication and education South Africa Eastern Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327111 , vital:61082 , DOI 10.21504/10962/327111
- Description: This modest research project was situated in a multilingual Early Childhood Development (ECD) setting in the Eastern Cape (EC) province of South Africa. In the context of high levels of poverty and unemployment in the EC, issues such as under-funding, the nature of the training of practitioners, translating the importance of learning through play into practice, difficulties dealing with diverse cultural practices and the use of multiple languages, all impact ECD provision. Research has shown that parental involvement and creating parent-school partnerships can assist children to progress at school. The overall objectives of this project were to explore how a team in an ECD centre might communicate more effectively with parents and how early stimulation practices in home and school might benefit the child’s development. The theoretical framework draws upon Vygotsky’s (1978) socio-cultural historical theory, Bernstein’s (1971) elaborated and restricted language codes and Bourdieu’s (1977) concepts of social reproduction. A research project in the Netherlands Thuis in School, used an education partnership approach (Iliás et al., 2019). They developed a manual that was adapted for our local context by drawing from the theories mentioned, and to counter the dominant approaches where parenting programs have often been offered from a deficit, narrow perspective. Action Research guided the interventionist approach to workshop sessions, to enable mutual capacity-building of parents and practitioners. To ensure informed consent, participants’ first languages were used. High risk factors related to photographs and videos of participating parents and minor children were successfully addressed. Pre- and post-interviews and workshop data were analysed using template analysis, within a constructivist paradigm. Findings include vignettes to introduce the contexts and parents' ideas prior to the sessions. Then, sessions are summarised as action cycles, with key participants' responses. Finally, post-session evaluations highlight the topics the parents found most meaningful; and parents’ and practitioner accounts of changes in practices. This research illustrates ways that educational partnership elements can influence practice and policy, to improve home and school environments for the benefit of children. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Authors: Maritz, Anneliese
- Date: 2022-10-04
- Subjects: Early childhood education Parent participation South Africa Eastern Cape , Early childhood teachers Training of , Home and school South Africa Eastern Cape , Parent-teacher relationships South Africa Eastern Cape , Communication and education South Africa Eastern Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327111 , vital:61082 , DOI 10.21504/10962/327111
- Description: This modest research project was situated in a multilingual Early Childhood Development (ECD) setting in the Eastern Cape (EC) province of South Africa. In the context of high levels of poverty and unemployment in the EC, issues such as under-funding, the nature of the training of practitioners, translating the importance of learning through play into practice, difficulties dealing with diverse cultural practices and the use of multiple languages, all impact ECD provision. Research has shown that parental involvement and creating parent-school partnerships can assist children to progress at school. The overall objectives of this project were to explore how a team in an ECD centre might communicate more effectively with parents and how early stimulation practices in home and school might benefit the child’s development. The theoretical framework draws upon Vygotsky’s (1978) socio-cultural historical theory, Bernstein’s (1971) elaborated and restricted language codes and Bourdieu’s (1977) concepts of social reproduction. A research project in the Netherlands Thuis in School, used an education partnership approach (Iliás et al., 2019). They developed a manual that was adapted for our local context by drawing from the theories mentioned, and to counter the dominant approaches where parenting programs have often been offered from a deficit, narrow perspective. Action Research guided the interventionist approach to workshop sessions, to enable mutual capacity-building of parents and practitioners. To ensure informed consent, participants’ first languages were used. High risk factors related to photographs and videos of participating parents and minor children were successfully addressed. Pre- and post-interviews and workshop data were analysed using template analysis, within a constructivist paradigm. Findings include vignettes to introduce the contexts and parents' ideas prior to the sessions. Then, sessions are summarised as action cycles, with key participants' responses. Finally, post-session evaluations highlight the topics the parents found most meaningful; and parents’ and practitioner accounts of changes in practices. This research illustrates ways that educational partnership elements can influence practice and policy, to improve home and school environments for the benefit of children. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2022
- Full Text:
Language Learning Anxiety: a bometric investigation of stress and language learning using wearable devices
- Authors: MacDonald, William Tait
- Date: 2022-10-04
- Subjects: Language and languages Study and teaching Psychological aspects , Wearable technology , Heart rate monitoring , Stress (Psychology) Testing , Anxiety Testing
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327133 , vital:61084 , DOI 10.21504/10962/327133
- Description: As Sapolsky (2015) notes, stress research has long been characterised by definitional debates that gave rise to a lack of agreement between theorists. An example of this definitional confusion can be seen in the area of Language Learning Anxiety, where there appears to be confusion in the literature over terms such as anxiety and stress. This study investigated the link between stress and language learning using wearable devices measuring heart rate variance, as a means of establishing the feasibility of using this new technology in stress research. The results indicate that the contextualised longitudinal data delivered by wearable devices mitigates against the current dominant paradigm in Language Learning Anxiety, which postulates a straight-line negative correlation between stress and learning. Instead, the inverted U stress relationship proposed by theorists such as Hebb (1955) seem to be a better fit for the data. The nature of the contextualised data generated in this study allowed for comparisons between participants’ stress readings in academic contexts, such as language and non-language classes, and their free time. The findings suggest that certain long-held assumptions about heightened stress in academic contexts may not hold true. While the findings of this study did not reach the levels of statistical significance, they constitute proof of concept that the type of contextualised data delivered by wearable devices may allow for a new type of stress research that incorporates contextualising longitudinal perspectives on participants’ stress levels. In this study the inclusion of contextualising data led to fundamentally different conclusions about the relationship between stress and language learning. The same may be true of many areas of stress research. The findings presented in this study have broader paradigm-altering implications not only for educational policy, but also for stress research in general. Perhaps equally important was that the type of data delivered by wearable devices was qualitatively different from that normally associated with quantitative studies. This presented challenges in data analysis in this study, but also opens intriguing possibilities regarding a means of reconciling the qualitative and quantitative split in research modalities. The use of wearable devices is not without issues, and some of the issues, ranging from practical considerations to ethical conundrums, are presented for the reader’s consideration and to inform future researchers regarding potential pitfalls. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Authors: MacDonald, William Tait
- Date: 2022-10-04
- Subjects: Language and languages Study and teaching Psychological aspects , Wearable technology , Heart rate monitoring , Stress (Psychology) Testing , Anxiety Testing
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327133 , vital:61084 , DOI 10.21504/10962/327133
- Description: As Sapolsky (2015) notes, stress research has long been characterised by definitional debates that gave rise to a lack of agreement between theorists. An example of this definitional confusion can be seen in the area of Language Learning Anxiety, where there appears to be confusion in the literature over terms such as anxiety and stress. This study investigated the link between stress and language learning using wearable devices measuring heart rate variance, as a means of establishing the feasibility of using this new technology in stress research. The results indicate that the contextualised longitudinal data delivered by wearable devices mitigates against the current dominant paradigm in Language Learning Anxiety, which postulates a straight-line negative correlation between stress and learning. Instead, the inverted U stress relationship proposed by theorists such as Hebb (1955) seem to be a better fit for the data. The nature of the contextualised data generated in this study allowed for comparisons between participants’ stress readings in academic contexts, such as language and non-language classes, and their free time. The findings suggest that certain long-held assumptions about heightened stress in academic contexts may not hold true. While the findings of this study did not reach the levels of statistical significance, they constitute proof of concept that the type of contextualised data delivered by wearable devices may allow for a new type of stress research that incorporates contextualising longitudinal perspectives on participants’ stress levels. In this study the inclusion of contextualising data led to fundamentally different conclusions about the relationship between stress and language learning. The same may be true of many areas of stress research. The findings presented in this study have broader paradigm-altering implications not only for educational policy, but also for stress research in general. Perhaps equally important was that the type of data delivered by wearable devices was qualitatively different from that normally associated with quantitative studies. This presented challenges in data analysis in this study, but also opens intriguing possibilities regarding a means of reconciling the qualitative and quantitative split in research modalities. The use of wearable devices is not without issues, and some of the issues, ranging from practical considerations to ethical conundrums, are presented for the reader’s consideration and to inform future researchers regarding potential pitfalls. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2022
- Full Text:
Views of the journey of grade 1 learners with barriers to learning, in the inclusive education system: a multi-level systemic investigation
- Van Vuuren, Cornelia Margaretha
- Authors: Van Vuuren, Cornelia Margaretha
- Date: 2022-10-04
- Subjects: Inclusive education South Africa Eastern Cape , Special education teachers South Africa Eastern Cape Attitudes , South Africa. Department of Education , Children with disabilities Education (Elementary) Government policy South Africa , Special education teachers Training of South Africa Eastern Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327122 , vital:61083 , DOI 10.21504/10962/327122
- Description: Embedded in South Africa’s humanitarian discourse, inclusive education (IE) followed global trends of inclusion of all people into wider society without discrimination. Inclusion in mainstream schools should also, according to the Salamanca agreement provide equal quality education, enabling learners with special educational needs (LSEN) to reach their full potential as a basic human right. IE started in South Africa with the implementation of the inclusive policy EWP6 in 2001. Including all children with barriers to learning in schools in their communities promoted social inclusion with their peers. The DoE introduced the Policy of Screening, Identification, Assessment and Support (SIAS) in 2014. This policy was implemented to assist teachers to identify learning barriers, as a means of offering support to these learners through the inclusive system. However, it seems that educators found this process cumbersome, without resources to maintain the process and with multiple systemic barriers preventing, rather than enhancing, support to LSEN. This multi-level systemic study explores the views of educators and other stakeholders on the effectiveness of the IE system in supporting LSEN, to serve the best interests of these learners in their first year of formal schooling. The study was conducted in three selected diverse mainstream Eastern Cape (EC) rural schools, involving the views of educators, district officials and parents. The study probed the impact of the inclusive system on LSEN’s development and social wellbeing, the perceived effects and benefits of the current system, and how the education model contributes towards human rights objectives and constitutional imperatives. The study acknowledges the theories and policies of the current inclusive system as promoting inclusion, but not being successfully realised in rural areas in the South African context, due to several systemic and contextual barriers. The findings revealed that although all participants noted the possible benefits of IE, the current system did not serve the individual educational needs of LSEN in rural mainstream schools, in their first formal year of schooling. Several constraints were reported including lack of resources, insufficient Allied Health support services, and insufficient training of educators. These lead to feelings of inadequacy in educators, along with systemic and contextual barriers and financial constraints in the schools. There also seems to be a need for better collaboration between education and other departments serving children and communities. To conclude, this study suggests a broader multi-level networked system, in which there needs to be greater interaction between the DoE and other government departments supporting children with barriers, like the Departments of Health (DoH), Social Development (DSD) and Justice (DoJ). , Thesis (PhD) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Authors: Van Vuuren, Cornelia Margaretha
- Date: 2022-10-04
- Subjects: Inclusive education South Africa Eastern Cape , Special education teachers South Africa Eastern Cape Attitudes , South Africa. Department of Education , Children with disabilities Education (Elementary) Government policy South Africa , Special education teachers Training of South Africa Eastern Cape
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/327122 , vital:61083 , DOI 10.21504/10962/327122
- Description: Embedded in South Africa’s humanitarian discourse, inclusive education (IE) followed global trends of inclusion of all people into wider society without discrimination. Inclusion in mainstream schools should also, according to the Salamanca agreement provide equal quality education, enabling learners with special educational needs (LSEN) to reach their full potential as a basic human right. IE started in South Africa with the implementation of the inclusive policy EWP6 in 2001. Including all children with barriers to learning in schools in their communities promoted social inclusion with their peers. The DoE introduced the Policy of Screening, Identification, Assessment and Support (SIAS) in 2014. This policy was implemented to assist teachers to identify learning barriers, as a means of offering support to these learners through the inclusive system. However, it seems that educators found this process cumbersome, without resources to maintain the process and with multiple systemic barriers preventing, rather than enhancing, support to LSEN. This multi-level systemic study explores the views of educators and other stakeholders on the effectiveness of the IE system in supporting LSEN, to serve the best interests of these learners in their first year of formal schooling. The study was conducted in three selected diverse mainstream Eastern Cape (EC) rural schools, involving the views of educators, district officials and parents. The study probed the impact of the inclusive system on LSEN’s development and social wellbeing, the perceived effects and benefits of the current system, and how the education model contributes towards human rights objectives and constitutional imperatives. The study acknowledges the theories and policies of the current inclusive system as promoting inclusion, but not being successfully realised in rural areas in the South African context, due to several systemic and contextual barriers. The findings revealed that although all participants noted the possible benefits of IE, the current system did not serve the individual educational needs of LSEN in rural mainstream schools, in their first formal year of schooling. Several constraints were reported including lack of resources, insufficient Allied Health support services, and insufficient training of educators. These lead to feelings of inadequacy in educators, along with systemic and contextual barriers and financial constraints in the schools. There also seems to be a need for better collaboration between education and other departments serving children and communities. To conclude, this study suggests a broader multi-level networked system, in which there needs to be greater interaction between the DoE and other government departments supporting children with barriers, like the Departments of Health (DoH), Social Development (DSD) and Justice (DoJ). , Thesis (PhD) -- Faculty of Humanities, Psychology, 2022
- Full Text:
Land expropriation without compensation: a study of constructions of the Parliamentary process in selected mainstream and “ground-up” media from 27 February – 12 August 2018
- Authors: Jacobs, Luzuko G
- Date: 2022-10
- Subjects: Discourse analysis , Communication Political aspects South Africa , Land reform Press coverage South Africa , Land reform Government policy South Africa , Communication in mass media , Frames (Sociology) South Africa , Journalism Political aspects South Africa , Moneyweb Holdings Ltd. , City Press (South Africa) , Afriforum (South Africa) , African Farmers’ Association of South Africa (AFASA)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/297807 , vital:57630 , DOI 10.21504/10962/297807
- Description: This study investigates the constructions of land expropriation without compensation (LEwC) in the discourses of two mainstream media, Moneyweb and City Press, and two ground-up platforms, Afriforum and the African Farmers’ Association of South Africa (AFASA). It follows the February 2018 adoption by Parliament, of LEwC as a policy to reorder the country’s unequal and racially bifurcated economy. The motivations for, and opposition to the policy locate land as ‘the issue’ in conquest and capitalism. How land is signified therefore, is important to the understandings of ‘restitution’ and/or ‘resolution’. The news platforms selected here are diverse: Moneyweb focuses on investments. City Press concerns itself with politics. Afriforum and AFASA are alternative sphericules linked to ethnically- polarised quotidian concerns with land as a key focus. Discourses are central to how citizens see and construct themselves and one another as subjects. As such, media frames can be connected to justice and inter-‘race’ complexities. This is a study of media influences in cultivating certain meanings and understandings of tenuous and fractious political situations characterised by inequality and interracial enmity. The thesis draws from the Epistemologies of the South as well as Marxism to constitute the locus of its enunciation of colonisation, liberal capitalism, land question, justice, ideology, discourse, and framing. This framework is geared towards emic understanding of interrelated local and global contexts of the land question. Conceptual clarity is key to the development of an emancipatory imagination. Qualitative framing analysis and critical discourse analysis are used in this study to examine a diachronic corpus of 124 articles from the four platforms covering 167-days, from the adoption of the LEwC motion through the initial round of public hearings. The findings suggest a strong influence of the structures of coloniality in discourses across a wide political spectrum. The frames and counter-frames in the four platforms are simultaneously divergent and similar. Some are reactionary and conservative, others are liberal-transformational and even radical-prefigurative. All however, orbit around abyssal, North-centric, liberal capitalist normativity as the centripetal centre. The study proposes rethinking of the land question, a radical exorcism from land discourses, of structures of coloniality of power, knowledge, and being. Their mobilisation, predominance and naturalisation in political communication is anti-transformation and helps keep Black South Africans to this day, under the heavy yoke of an oppressive colonial and Apartheid reality as perpetual economic slaves. , Thesis (PhD) -- Faculty of Humanities, Journalism and Media Studies, 2022
- Full Text:
- Authors: Jacobs, Luzuko G
- Date: 2022-10
- Subjects: Discourse analysis , Communication Political aspects South Africa , Land reform Press coverage South Africa , Land reform Government policy South Africa , Communication in mass media , Frames (Sociology) South Africa , Journalism Political aspects South Africa , Moneyweb Holdings Ltd. , City Press (South Africa) , Afriforum (South Africa) , African Farmers’ Association of South Africa (AFASA)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/297807 , vital:57630 , DOI 10.21504/10962/297807
- Description: This study investigates the constructions of land expropriation without compensation (LEwC) in the discourses of two mainstream media, Moneyweb and City Press, and two ground-up platforms, Afriforum and the African Farmers’ Association of South Africa (AFASA). It follows the February 2018 adoption by Parliament, of LEwC as a policy to reorder the country’s unequal and racially bifurcated economy. The motivations for, and opposition to the policy locate land as ‘the issue’ in conquest and capitalism. How land is signified therefore, is important to the understandings of ‘restitution’ and/or ‘resolution’. The news platforms selected here are diverse: Moneyweb focuses on investments. City Press concerns itself with politics. Afriforum and AFASA are alternative sphericules linked to ethnically- polarised quotidian concerns with land as a key focus. Discourses are central to how citizens see and construct themselves and one another as subjects. As such, media frames can be connected to justice and inter-‘race’ complexities. This is a study of media influences in cultivating certain meanings and understandings of tenuous and fractious political situations characterised by inequality and interracial enmity. The thesis draws from the Epistemologies of the South as well as Marxism to constitute the locus of its enunciation of colonisation, liberal capitalism, land question, justice, ideology, discourse, and framing. This framework is geared towards emic understanding of interrelated local and global contexts of the land question. Conceptual clarity is key to the development of an emancipatory imagination. Qualitative framing analysis and critical discourse analysis are used in this study to examine a diachronic corpus of 124 articles from the four platforms covering 167-days, from the adoption of the LEwC motion through the initial round of public hearings. The findings suggest a strong influence of the structures of coloniality in discourses across a wide political spectrum. The frames and counter-frames in the four platforms are simultaneously divergent and similar. Some are reactionary and conservative, others are liberal-transformational and even radical-prefigurative. All however, orbit around abyssal, North-centric, liberal capitalist normativity as the centripetal centre. The study proposes rethinking of the land question, a radical exorcism from land discourses, of structures of coloniality of power, knowledge, and being. Their mobilisation, predominance and naturalisation in political communication is anti-transformation and helps keep Black South Africans to this day, under the heavy yoke of an oppressive colonial and Apartheid reality as perpetual economic slaves. , Thesis (PhD) -- Faculty of Humanities, Journalism and Media Studies, 2022
- Full Text:
Developing taxonomic and trait-based approaches for assessing and predicting macroinvertebrate responses to elevated fine sediments in the Tsitsa River and its tributaries, South Africa
- Authors: Ntloko, Pindiwe
- Date: 2022-04-08
- Subjects: Water quality South Africa Mzimvubu River Watershed , Sedimentation and deposition South Africa Mzimvubu River Watershed , Aquatic invertebrates Effect of sediments on South Africa Mzimvubu River Watershed , Aquatic invertebrates Classification , Environmental monitoring South Africa Mzimvubu River Watershed , Analysis of variance , Multivariate analysis
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294692 , vital:57245 , DOI 10.21504/10962/294692
- Description: Sedimentation of freshwater systems is one of the leading causes of water quality deterioration. The Mzimvubu River catchment, which includes the Tsitsa River and its tributaries, in the Eastern Cape is prone to elevated sediment impact due to dispersive soils that are easily erodible. In this study, taxonomy and trait-based approaches were used to assess the responses of macroinvertebrates to fine sediments in the Tsitsa River and its tributaries. Macroinvertebrates and environmental variables were sampled seasonally in winter, spring, summer and autumn of 2016 to 2018 in six selected sites, using the South African Scoring System version 5 as a collecting protocol. The sites were selected to represent a decreasing gradient of sediment influence from the highly impacted Sites 1 (Tsitsa upstream) 2 (Tsitsa downstream), and 3 (Qurana River) to moderately impacted Sites 4 (Millstream upstream) and 5 (Millstream downstream) and the least impacted Sites 6 (Pot River upstream), 7 (Little Pot River) and 8 (Pot River downstream), which were collectively referred to as the control sites. Analysis of basic physico-chemical variables, dissolved oxygen, pH, electrical conductivity, turbidity, total suspended solids, temperature and nutrients were undertaken seasonally over the study period. Sediments grain sizes were also analysed. All collected data were subjected to appropriate statistical tests – univariate and multivariate techniques. A fine-sediment-specific multimetric index was developed to monitor the impact of fine sediments on macroinvertebrate assemblages of the Tsitsa River and its tributaries. A total of 12 traits, resolved into 48 trait attributes, were selected to explore their distribution in relation to a fine-sediment stress gradient, and identify the trait-based signature of fine-sediment impact. A trait-based approach was then developed to classify South African macroinvertebrates into two groups: taxa that are potentially vulnerable to fine-sediment impact and those potentially resilient, based on the combination of traits possessed. Two-way analysis of variance (ANOVA) indicated that electrical conductivity, turbidity, embeddedness and total suspended solids were statistically significantly different between the sites. Apart from Dissolved oxygen, the remaining variables were statistically significantly lower at the control sites (P < 0.05). The two-way multivariate analysis of variance (MANOVA) indicated global significant differences between sites and seasons. The two-way MANOVA also revealed that the interaction between the sites and seasons were statistically significant. The MANOVA indicated global combined interactive effects across the sites for suspended fine-sediment grain sizes, two-way ANOVA, followed by a Tukey’s post-hoc test, was carried out to indicate where the significant differences lay. The one-way ANOVA results indicated that very fine sand, very coarse silt, medium silt, and fine silt were significantly higher at Tsitsa upstream, Tsitsa downstream, Qurana tributary that is at Millstream upstream, Millstream downstream and Control sites. The rest of the grain sizes did not differ statistically between the sites. In terms of the settled sediment grain sizes, the volumetric analysis did not show considerable differences across the sites. Settled fine-sediment grain sizes were evenly distributed across the sites. Statistically, MANOVA results indicated no significant differences across sites or across seasons. The developed Sediment Multimetric Index indicated that the sites in the Tsitsa River and those in the Qurana River were highly sedimented during the wet season, but became moderately sedimented during the dry season, indicating that the index responded to seasonality. The sediment multimetric index indicated that the control sites were less sedimented during both the wet season and dry seasons, suggesting minimal seasonal effects at the control sites. Traits such as an exposed and soft body, collector-filterers, shredding, feeding on coarse particulate organic matter and a high sensitivity to dissolved oxygen were identified as fine- sediment-sensitive indicator traits. Identified fine-sediment-tolerant traits and ecological preferences included complete sclerotisation, a cased/tubed body, a preference for fine particulate organic matter, a high tolerance to dissolved oxygen depletion, and climbing and skating behaviours. Regarding the trait-based approach followed for classifying macroinvertebrates into vulnerable taxa and resilient taxa, the results revealed that the relative abundance and richness of the vulnerable taxa decreased predictably along the increasing gradient of sediment impact. However, the relative abundance and richness of resilient taxa showed no marked response to the impact of an increasing gradient of fine sediments. Overall, the present study makes a contribution to the complementary application of trait-and taxonomy-based approaches to freshwater biomonitoring. The trait-based approach enables predictions to be made and tested based on the mechanistic understanding of the mediating roles of traits in organism- environment interaction. A fundamental challenge, which showcases the limitation of the current study, is the sparse trait data on Afrotropical macroinvertebrates at the species or generic levels. In this regard, the iv trait-based approaches developed here were the family level instead of species or genus. This is the first study in South Africa to develop explicit trait-based indicators of elevated fine sediments as well as an approach for predicting macroinvertebrate vulnerability and resilience to fine-sediment effects, thus advancing the science and practice of freshwater biomonitoring. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2022
- Full Text:
- Authors: Ntloko, Pindiwe
- Date: 2022-04-08
- Subjects: Water quality South Africa Mzimvubu River Watershed , Sedimentation and deposition South Africa Mzimvubu River Watershed , Aquatic invertebrates Effect of sediments on South Africa Mzimvubu River Watershed , Aquatic invertebrates Classification , Environmental monitoring South Africa Mzimvubu River Watershed , Analysis of variance , Multivariate analysis
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294692 , vital:57245 , DOI 10.21504/10962/294692
- Description: Sedimentation of freshwater systems is one of the leading causes of water quality deterioration. The Mzimvubu River catchment, which includes the Tsitsa River and its tributaries, in the Eastern Cape is prone to elevated sediment impact due to dispersive soils that are easily erodible. In this study, taxonomy and trait-based approaches were used to assess the responses of macroinvertebrates to fine sediments in the Tsitsa River and its tributaries. Macroinvertebrates and environmental variables were sampled seasonally in winter, spring, summer and autumn of 2016 to 2018 in six selected sites, using the South African Scoring System version 5 as a collecting protocol. The sites were selected to represent a decreasing gradient of sediment influence from the highly impacted Sites 1 (Tsitsa upstream) 2 (Tsitsa downstream), and 3 (Qurana River) to moderately impacted Sites 4 (Millstream upstream) and 5 (Millstream downstream) and the least impacted Sites 6 (Pot River upstream), 7 (Little Pot River) and 8 (Pot River downstream), which were collectively referred to as the control sites. Analysis of basic physico-chemical variables, dissolved oxygen, pH, electrical conductivity, turbidity, total suspended solids, temperature and nutrients were undertaken seasonally over the study period. Sediments grain sizes were also analysed. All collected data were subjected to appropriate statistical tests – univariate and multivariate techniques. A fine-sediment-specific multimetric index was developed to monitor the impact of fine sediments on macroinvertebrate assemblages of the Tsitsa River and its tributaries. A total of 12 traits, resolved into 48 trait attributes, were selected to explore their distribution in relation to a fine-sediment stress gradient, and identify the trait-based signature of fine-sediment impact. A trait-based approach was then developed to classify South African macroinvertebrates into two groups: taxa that are potentially vulnerable to fine-sediment impact and those potentially resilient, based on the combination of traits possessed. Two-way analysis of variance (ANOVA) indicated that electrical conductivity, turbidity, embeddedness and total suspended solids were statistically significantly different between the sites. Apart from Dissolved oxygen, the remaining variables were statistically significantly lower at the control sites (P < 0.05). The two-way multivariate analysis of variance (MANOVA) indicated global significant differences between sites and seasons. The two-way MANOVA also revealed that the interaction between the sites and seasons were statistically significant. The MANOVA indicated global combined interactive effects across the sites for suspended fine-sediment grain sizes, two-way ANOVA, followed by a Tukey’s post-hoc test, was carried out to indicate where the significant differences lay. The one-way ANOVA results indicated that very fine sand, very coarse silt, medium silt, and fine silt were significantly higher at Tsitsa upstream, Tsitsa downstream, Qurana tributary that is at Millstream upstream, Millstream downstream and Control sites. The rest of the grain sizes did not differ statistically between the sites. In terms of the settled sediment grain sizes, the volumetric analysis did not show considerable differences across the sites. Settled fine-sediment grain sizes were evenly distributed across the sites. Statistically, MANOVA results indicated no significant differences across sites or across seasons. The developed Sediment Multimetric Index indicated that the sites in the Tsitsa River and those in the Qurana River were highly sedimented during the wet season, but became moderately sedimented during the dry season, indicating that the index responded to seasonality. The sediment multimetric index indicated that the control sites were less sedimented during both the wet season and dry seasons, suggesting minimal seasonal effects at the control sites. Traits such as an exposed and soft body, collector-filterers, shredding, feeding on coarse particulate organic matter and a high sensitivity to dissolved oxygen were identified as fine- sediment-sensitive indicator traits. Identified fine-sediment-tolerant traits and ecological preferences included complete sclerotisation, a cased/tubed body, a preference for fine particulate organic matter, a high tolerance to dissolved oxygen depletion, and climbing and skating behaviours. Regarding the trait-based approach followed for classifying macroinvertebrates into vulnerable taxa and resilient taxa, the results revealed that the relative abundance and richness of the vulnerable taxa decreased predictably along the increasing gradient of sediment impact. However, the relative abundance and richness of resilient taxa showed no marked response to the impact of an increasing gradient of fine sediments. Overall, the present study makes a contribution to the complementary application of trait-and taxonomy-based approaches to freshwater biomonitoring. The trait-based approach enables predictions to be made and tested based on the mechanistic understanding of the mediating roles of traits in organism- environment interaction. A fundamental challenge, which showcases the limitation of the current study, is the sparse trait data on Afrotropical macroinvertebrates at the species or generic levels. In this regard, the iv trait-based approaches developed here were the family level instead of species or genus. This is the first study in South Africa to develop explicit trait-based indicators of elevated fine sediments as well as an approach for predicting macroinvertebrate vulnerability and resilience to fine-sediment effects, thus advancing the science and practice of freshwater biomonitoring. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2022
- Full Text:
Dynamics of charge movement in ∞-Al2O3:C,Mg using thermoluminescence phototransferred and optically stimulated luminescence
- Authors: Lontsi Sob, Aaron Joel
- Date: 2022-04-08
- Subjects: Thermoluminescence , Optically stimulated luminescence , Phototransfer , Deep traps , Phototransferred thermoluminescence (PTTL)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294607 , vital:57237 , DOI 10.21504/10962/294607
- Description: The dosimetric features of ∞-Al2O3:C,Mg have been investigated for unannealed and annealed samples. The unannealed sample is referred to as sample A whereas the samples annealed at 700, 900 and 1200°C for 15 minutes each are referred to as samples B, C and D respectively. A glow curve of unannealed ∞-Al2O3:C,Mg measured at 1°C/s after irradiation to 2.0 Gy consists of peaks at 43, 73, 164, 195, 246, 284, 336 and 374°C respectively. For sample B (annealed at 700°C), a glow curve measured at 1°C/s after irradiation to 3.0 Gy has peaks at 46, 76, 100, 170, 199, 290, 330 and 375°C whereas the glow curve of sample C (annealed at 900°C) recorded under the same conditions consists of peaks at 49, 80, 100, 174, 206, 235, 290, 335 and 375°C respectively. Sample D (annealed at 1200°C) is the most sensitive of the four samples. A glow curve of sample D measured at 1°C/s after irradiation to 0.2 Gy has peaks at 52, 82, 102, 174, 234, 288 and 384°C respectively. The peaks are labelled I-VIII in order of appearance. The 100°C peak, labelled IIa, is induced by annealing at or above 700°C. The dose response of these peaks was studied for doses within 0.1-8.2 Gy. The reported peaks follow first-order kinetics irrespective of annealing temperature. Peaks I-III of each sample are reproduced under phototransfer for preheating up to 400°C. For the unannealed sample, the reproduced peaks are labelled A1-A3 whereas for the annealed samples, they are labelled B1-B3, C1-C3 and D1-D3 respectively. The annealing-induced peak at 100°C is reproduced as B2a, C2a and D2a for samples B, C and D respectively. A PTTL peak labelled C2b or D2b is also observed near 140°C in samples C and D. In addition to these PTTL peaks, a PTTL peak corresponding to peak IV is also found for sample D and for the unannealed sample. As the corresponding conventional peaks, the PTTL peaks of each sample follow first-order kinetics. Peak I and its corresponding PTTL peak for each sample are unstable and fade to a minimal level after 300 s of storage time. On the other hand, peak II of each sample and its corresponding PTTL peak could still be observed with delay up to 5000 s. Peak III of the unannealed sample remains stable with storage time up to 48 hours. Irrespective of annealing, the trap corresponding to peak III is the most sensitive to optical stimulation. Time-dependent profiles of PTTL from unannealed and annealed ∞-Al2O3:C,Mg were also studied. The mathematical analysis of the PTTL time-response profiles is based on experimental results. The role of various electron traps in PTTL was determined by using pulse annealing and by monitoring the dependence of peak intensity on duration of illumination for peaks not removed by preheating. The presence and role of deep traps were further demonstrated with thermally assisted optically stimulated luminescence. For the unannealed sample, the activation energy for thermal assistance is 0.033 ± 0.001 eV and the activation energy for thermal i quenching is 1.043 ± 0.001 eV. For sample C, the activation energy for thermal assistance is 0.044 ± 0.003 eV whereas that for thermal quenching is 1.110 ± 0.006 eV. The values for the activation energy for thermal assistance are lower than those reported in literature. Only the values for the activation energy for thermal quenching are somewhat comparable to values reported elsewhere. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2022
- Full Text:
- Authors: Lontsi Sob, Aaron Joel
- Date: 2022-04-08
- Subjects: Thermoluminescence , Optically stimulated luminescence , Phototransfer , Deep traps , Phototransferred thermoluminescence (PTTL)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294607 , vital:57237 , DOI 10.21504/10962/294607
- Description: The dosimetric features of ∞-Al2O3:C,Mg have been investigated for unannealed and annealed samples. The unannealed sample is referred to as sample A whereas the samples annealed at 700, 900 and 1200°C for 15 minutes each are referred to as samples B, C and D respectively. A glow curve of unannealed ∞-Al2O3:C,Mg measured at 1°C/s after irradiation to 2.0 Gy consists of peaks at 43, 73, 164, 195, 246, 284, 336 and 374°C respectively. For sample B (annealed at 700°C), a glow curve measured at 1°C/s after irradiation to 3.0 Gy has peaks at 46, 76, 100, 170, 199, 290, 330 and 375°C whereas the glow curve of sample C (annealed at 900°C) recorded under the same conditions consists of peaks at 49, 80, 100, 174, 206, 235, 290, 335 and 375°C respectively. Sample D (annealed at 1200°C) is the most sensitive of the four samples. A glow curve of sample D measured at 1°C/s after irradiation to 0.2 Gy has peaks at 52, 82, 102, 174, 234, 288 and 384°C respectively. The peaks are labelled I-VIII in order of appearance. The 100°C peak, labelled IIa, is induced by annealing at or above 700°C. The dose response of these peaks was studied for doses within 0.1-8.2 Gy. The reported peaks follow first-order kinetics irrespective of annealing temperature. Peaks I-III of each sample are reproduced under phototransfer for preheating up to 400°C. For the unannealed sample, the reproduced peaks are labelled A1-A3 whereas for the annealed samples, they are labelled B1-B3, C1-C3 and D1-D3 respectively. The annealing-induced peak at 100°C is reproduced as B2a, C2a and D2a for samples B, C and D respectively. A PTTL peak labelled C2b or D2b is also observed near 140°C in samples C and D. In addition to these PTTL peaks, a PTTL peak corresponding to peak IV is also found for sample D and for the unannealed sample. As the corresponding conventional peaks, the PTTL peaks of each sample follow first-order kinetics. Peak I and its corresponding PTTL peak for each sample are unstable and fade to a minimal level after 300 s of storage time. On the other hand, peak II of each sample and its corresponding PTTL peak could still be observed with delay up to 5000 s. Peak III of the unannealed sample remains stable with storage time up to 48 hours. Irrespective of annealing, the trap corresponding to peak III is the most sensitive to optical stimulation. Time-dependent profiles of PTTL from unannealed and annealed ∞-Al2O3:C,Mg were also studied. The mathematical analysis of the PTTL time-response profiles is based on experimental results. The role of various electron traps in PTTL was determined by using pulse annealing and by monitoring the dependence of peak intensity on duration of illumination for peaks not removed by preheating. The presence and role of deep traps were further demonstrated with thermally assisted optically stimulated luminescence. For the unannealed sample, the activation energy for thermal assistance is 0.033 ± 0.001 eV and the activation energy for thermal i quenching is 1.043 ± 0.001 eV. For sample C, the activation energy for thermal assistance is 0.044 ± 0.003 eV whereas that for thermal quenching is 1.110 ± 0.006 eV. The values for the activation energy for thermal assistance are lower than those reported in literature. Only the values for the activation energy for thermal quenching are somewhat comparable to values reported elsewhere. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2022
- Full Text:
Inhibition of aluminium corrosion using phthalocyanines: Experimental and computational studies
- Authors: Nnaji, Nnaemeka Joshua
- Date: 2022-04-08
- Subjects: Aluminum Corrosion , Electrochemistry , Phthalocyanines , Corrosion and anti-corrosives , Protective coatings , Density functionals
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294643 , vital:57240 , DOI 10.21504/10962/294643
- Description: Metal deterioration over time is a process known as corrosion, an electrochemical process, which can occur by surface chemical actions on metals by its environment. Metal corrosion have great economic, security, and environmental consequences, and its control is a major research area in corrosion science. Amongst the different corrosion protecting approaches, the use of corrosion inhibitors and protective coatings have attracted enormous research interest in this area of scholasticism. This has necessitated the computational and electrochemical investigations of aluminium corrosion inhibitive potentials of some compounds in 1M HCl. Metal free (5_H2), ClGa(III) (5_Ga) and Co(II) (5_Co) tetrakis(4-acetamidophenoxy)phthalocyanines as well as Co(II) 2,9,16-tris(4-(tert-butyl)phenoxy)-23-(pyridin-4-yloxy)phthalocyanine (6) and Co(II) 2,9,16,24-tetrakis(4-(tert-butyl)phenoxy)phthalocyanine (7) were synthesized for the first time and studied for corrosion inhibition. The reported ClGa(III) tetrakis(benzo[d]thiazol-2-yl-thio)phthalocyaninine (1), ClGa(III) tetrakis(benzo[d]thiazol-2ylphenoxy)phthalocyanine (2), ClGa(III) tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyanine) (3) and ClGa(III) tetrakis-4,4′-((4-(benzo[d]thiazol-2-yl)-1,2-bis(phenoxy)-bis(phthalocyanine) (4) were also employed for corrosion inhibition of Al in HCl. Corrosion inhibition measurements using electrochemical techniques showed that increased π conjugation caused (1) to (2) to outperform (1a) and (2a) respectively as aluminium corrosion inhibitors in 1.0 M hydrochloric acid. For similar reason, (4) outperformed 2. (1) and (2) were successfully electrodeposited onto aluminium for corrosion retardation in 1.0 M hydrochloric acid solution. Measurements obtained from electrochemical impedance spectroscopy gave corrosion inhibition efficiency values of 82% for 1 and 86% for 2 in 1.0 M hydrochloric acid solution and showed that electrodeposited phthalocyanines have enhanced aluminium corrosion retardation than when in solution. The use of reduced graphene oxide nanosheets (rGONS) alone as aluminium corrosion inhibitor is discouraged because of poor aluminium corrosion inhibition in 1M HCl. However, synergistic effects were observed when rGONS was mixed each with (4) and (3). (5_H2), (5_Ga) and (5_Co) decreased aluminium corrosion in 1M HCl and observation was that the heavier the atom the more decreased the protection and the free base performed best of the three. Studied tertbutylphenoxy-derived CoPcs (6 and 7) exhibited good aluminium corrosion inhibition properties in studied acidic solution and the unsymmetric CoPc (6) which has more heteroatoms, gave better performance. Quantum chemical calculations involved the use of density functional theoretical (DFT) approaches and gave results which corroborated with experimental findings. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Authors: Nnaji, Nnaemeka Joshua
- Date: 2022-04-08
- Subjects: Aluminum Corrosion , Electrochemistry , Phthalocyanines , Corrosion and anti-corrosives , Protective coatings , Density functionals
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294643 , vital:57240 , DOI 10.21504/10962/294643
- Description: Metal deterioration over time is a process known as corrosion, an electrochemical process, which can occur by surface chemical actions on metals by its environment. Metal corrosion have great economic, security, and environmental consequences, and its control is a major research area in corrosion science. Amongst the different corrosion protecting approaches, the use of corrosion inhibitors and protective coatings have attracted enormous research interest in this area of scholasticism. This has necessitated the computational and electrochemical investigations of aluminium corrosion inhibitive potentials of some compounds in 1M HCl. Metal free (5_H2), ClGa(III) (5_Ga) and Co(II) (5_Co) tetrakis(4-acetamidophenoxy)phthalocyanines as well as Co(II) 2,9,16-tris(4-(tert-butyl)phenoxy)-23-(pyridin-4-yloxy)phthalocyanine (6) and Co(II) 2,9,16,24-tetrakis(4-(tert-butyl)phenoxy)phthalocyanine (7) were synthesized for the first time and studied for corrosion inhibition. The reported ClGa(III) tetrakis(benzo[d]thiazol-2-yl-thio)phthalocyaninine (1), ClGa(III) tetrakis(benzo[d]thiazol-2ylphenoxy)phthalocyanine (2), ClGa(III) tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyanine) (3) and ClGa(III) tetrakis-4,4′-((4-(benzo[d]thiazol-2-yl)-1,2-bis(phenoxy)-bis(phthalocyanine) (4) were also employed for corrosion inhibition of Al in HCl. Corrosion inhibition measurements using electrochemical techniques showed that increased π conjugation caused (1) to (2) to outperform (1a) and (2a) respectively as aluminium corrosion inhibitors in 1.0 M hydrochloric acid. For similar reason, (4) outperformed 2. (1) and (2) were successfully electrodeposited onto aluminium for corrosion retardation in 1.0 M hydrochloric acid solution. Measurements obtained from electrochemical impedance spectroscopy gave corrosion inhibition efficiency values of 82% for 1 and 86% for 2 in 1.0 M hydrochloric acid solution and showed that electrodeposited phthalocyanines have enhanced aluminium corrosion retardation than when in solution. The use of reduced graphene oxide nanosheets (rGONS) alone as aluminium corrosion inhibitor is discouraged because of poor aluminium corrosion inhibition in 1M HCl. However, synergistic effects were observed when rGONS was mixed each with (4) and (3). (5_H2), (5_Ga) and (5_Co) decreased aluminium corrosion in 1M HCl and observation was that the heavier the atom the more decreased the protection and the free base performed best of the three. Studied tertbutylphenoxy-derived CoPcs (6 and 7) exhibited good aluminium corrosion inhibition properties in studied acidic solution and the unsymmetric CoPc (6) which has more heteroatoms, gave better performance. Quantum chemical calculations involved the use of density functional theoretical (DFT) approaches and gave results which corroborated with experimental findings. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
Quantifying the impacts of cactus biological control agents in South Africa
- Authors: Mnqeta, Zezethu
- Date: 2022-04-08
- Subjects: Cactus Biological control South Africa , Noxious weeds South Africa , Invasive plants Biological control South Africa , Insects as biological pest control agents South Africa , Cochineal insect South Africa , Mealybugs South Africa , Agricultural productivity South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294631 , vital:57239 , DOI 10.21504/10962/294631
- Description: Invasive alien cacti are prominent weeds that threaten indigenous biodiversity and have a negative impact on agricultural productivity in South Africa. These plants are problematic because they form dense thickets that reduce the carrying capacity of rangelands; restrict the movement of livestock and wildlife thus reducing access to shade and water sources; and are directly harmful to livestock, wildlife and people due to their sharp spines. Biological control is the most effective, affordable and environmentally friendly method to control invasive alien cacti and minimize their negative impacts. Cochineal insects (Dactylopius spp.: Dactylopiidae) and the gall-forming mealybug, Hypogeococcus sp. (Pseudococcidae) are used as biological control agents for cacti. The agents are however poor dispersers, so mass-rearing and augmentative releases are required in order to establish the agents at sites where they are needed. This study aimed to evaluate the mass-rearing and release efforts of cactus biological control in South Africa, quantify the impact of the biological control agents on cactus plant populations through long-term monitoring, and assess the benefits accrued due to the biological control agents through the perceptions of land-users. An assessment of the effectiveness of the release effort for cactus biological control agents was conducted by comparing where biological control agents have been released with the known distribution of the target weeds. Only 26% of the quarter degree squares that are known to be occupied by invasive alien cacti have had biological control agents released in them. This indicated that the mass-rearing and release efforts in South Africa are inadequate and should be increased, especially in areas where few releases have been made and many cacti are present, such as the Limpopo Province. The impact of the biological control agents on cactus plant populations was assessed by monitoring agent densities, target plant densities and target plant reproductive outputs before and after releases. Plant biomass and reproductive output were reduced by biological control agents for three of the target weeds that were assessed, while the duration of the study was too short to measure reductions for the fourth target weed. Benefits to land-users were then quantified through a questionnaire survey. Land-users perceived biological control as an effective management option, with 81% of the land-users reporting that there was less invasive alien cactus after releasing biological control agents on their land. Forty-nine percent of the land-users believed that the negative impacts of the cactus had been reduced and that they benefited more from their land since control was achieved. Since land-users were only interviewed within four years of the releases being conducted, it is expected that the percentage of land-users who gained benefits from biological control will increase in future. Ninety-seven percent of the land-users stated that the agents were safe and had not fed on any other plants or had any detrimental impacts. These perceptions indicated that land-users regarded biological control as a safe and effective method of controlling invasive alien cacti. This study confirms that biological control is an effective and safe way of controlling invasive alien Cactaceae. It is also the first to assess some of the benefits that land-users have accrued due to biological control of cactus weeds. It is however evident that a greater mass-rearing and release effort is required for South Africa to get the maximum benefits possible from the use of the biological control agents for cactus weeds that are available in the country. , Izityalo ze-cactus ezisuka kwamanye amazwe zilukhula olubalaseleyo, olwenza ingxaki kwintlobo ngeentlobo zezityalo nezilwanyana kwaye ezizityalo zinefuthe neziphumo ezingalunganga kwimveliso yezolimo eMzantsi Afrika. Ezi zizityalo ziyingxaki kuba zenza amatyholo ashinyeneyo athi anciphise umthamo wokusebenzisa umhlaba: zinqanda ukuhamba nogkukhululekileyo kwemfuyo nezilwanyana zasendle ngokwenza oko zingakwazi ukufikelela emthuzini xa kutshisa nakwimithombo yamanzi yokusela; zikwayiyo nengozi kwimfuyo, izilwanyana zasendle kunye nabantu ngenxa yamave abukhali afumaneka kwezizityalo. Ukulawula nokwehliza ubunzini nezinga lemigcipheko yezizityalo, kusetyenziswa indlela ekuthiwa yi-biological control. Lendlela yeyona ndlela isebenza ngokuphucukileyo, efikelelayo, nengenabungozi kokusingqongileyo. Izinambuzane ze- cochineal (i-Dactylopius spp.: Dactylopiidae) kunye ne-mealybug, i-Hypogeococcus sp. (Pseudococcidae) zisetyenziswe njengezixhobo ze-biological control ezinceda ukulawula ezizityalo ze-cactus zingafunekiyo. Ingxaki yazo ezizinambuzane zizixhobo ze-biological control zingentla kukuba azikwazi kuzisasaza ngokwazo ukuba zifikelele nakwizityalo ezikude ngoko ke ukukhuliswa nokukhutshwa ngobuninzi bazo kuyafuneka ukukhawulelana nalengxaki kunye nokwandisa amathuba wokuba zifikelele kuzozonke izityalo ze-cactus ekufuneka zizilawule. Olu phononongo lujolise ekuvavanyeni iinzame zokukhulisa ngobuninzi nokukhupha ezezinambuzane zizixhobo ze-bioloigical control zokulawula izityalo ze-cactus eMzantsi Afrika, ukujonga ubungakanani befuthe notshintsho elenziwa zezinambuzane zizixhobo ze-bioloigical control kwizityalo ze-cactus emva kwexesha elide lokuzijonga, kunye nokuvavanya inzuzo efunyenwe ngenxa yokulawula ezizityalo ze-cactus ngokwemibono yabasebenzisi bomhlaba. Uvavanyo lweenzame zokukhutshwa kwezixhobo zezixhobo zezinambuzane ze-bioloigical control kwizityalo ze-cactus lwenziwa ngokuthelekisa iindawo apho izixhobo zezinambuzane ze-biological control zikhutshwe khona kunye neendawo apho izityalo ze-cactus kwaziwayo ukuba ziyafumaneka khona. Yi-26% kuphela yesikwere sekota eyaziwayo ukuba kukhona izityalo ze-cactus nalapho kukhutshwe khona kwezinambuzane ezizixhobo ze-biological control. Oku kubonisa ukuba iinzame zokukhulisa nokukhutshwa kwezinambuzane ezizixhobo ze-biological control eMzantsi Afrika azanelanga kwaye kufuneka zandiswe, ngakumbi kwiindawo apho kukho ukhutsho olumbalwa olwenziweyo kunye nezityalo ze-cactus ezininzi ezifumaneka khona, njengePhondo laseLimpopo. Iimpembelelo yokukhutshwa kwezinambuzane ezizixhobo ze-biological control kwizityalo ze-cactus zavavanywa ngokujonga ubunizi bezinambuzane ezizixhobo ze-biological control, ukuxinana kwezityalo ze-cactus ekujoliswe kuzo kunye nemveliso yokuzala kwezityalo ze-cactus phambi nasemva kokuba kukhutshwe izinambuzane ezizixhobo ze-biological control. Ubungakanani bezityalo ze-cactus kunye nemveliso yokuzala ziye zacutheka emva kokukhutshwa kwezinambuzane ezizixhobo ze-biological control kwinzityalo ezintathu ze-cactus ebekujoliswe uvavanyo kuzo, ngelixa ixesha lophononongo lalifutshane kakhulu ukuvavanya unciphiso kwisityalo se-cactus sesine. Izibonelelo zabasebenzisi bomhlaba zaye zavavanywa kusetyenziswa uhlobo lwemibuzo. Abasebenzisi bomhlaba balubona ukusetyenziswa kwezinambuzane ezizixhobo ze-biological control njengendlela yolawulo olusebenzayo, yi81% yabasebenzisi bomhlaba echaze ukuba izityalo ze-cactus zecuthekile emva kokukhutshwa kwezinambuzane ezizixhobo ze-biological control emhlabeni wabo. Amashumi amane anesithoba eepesenti zabasebenzisi bomhlaba bakholelwa ukuba impembelelo ezingalunganga ze-cactus zincitshisiwe kwaye baxhamle kakhulu kumhlaba wabo okoko lwaphunyenzwa. Oludliwano-ndlebe belwenziwe kubasebenzisi bomhlaba kwisithuba seminyaka emine emva kokuba kukhutshwe izinambuzane ezizixhobo ze-biological control, kulindeleke ukuba ipesenti yabasebenzisi bomhlaba abathe bafumana izibonelelo kwi-biological control lonyuke kwixesha elizayo. Amashumi alithoba anesixhenxe ekhulwini abasebenzisi bomhlaba bachaze ukuba izinambuzane ezizixhobo ze-biological control zikhuselekile kwaye khange zidle kuzo naziphi na ezinye izityalo ezingezi eze-cactus ebekujoliswe kuzo okanye zineempembelelo eyingozi. Ezi mbono ziyabonisa ukuba abasebenzi bomhlaba bayithatha i-biological control njengendlela ekhuselekileyo nesebenzayo yokulawula izityalo ze-cactus zamanye amazwe. Olu phononongo luqinisekisa ukuba ulawulo olusebenzisa izinambuzane ezizixhobo ze-biological control yindlela esebenzayo nekhuselekileyo yokulawula iCactaceae yamanye amazwe. Ikwangolokuqala ukuvavanya ezinye zezibonelelo ezizuzwe ngabasebenzisi bomhlaba ngenxa ye-biological control yezityalo ze-cactus. Nangona kunjalo kucacile ukuba ukwandisa inzame zokukhulisa nokukhupha ngobuninzi izinambuzane ezizixhobo ze-biological control kuyafuneka ukuze uMzantsi Afrika ufumane izibonelelo eziphakamileyo enokubakho ngokusetyenziswa kwe zinambuzane ezizixhobo ze-biological control zokulawula ukhula lwe-cactus olukhoyo kweli lizwe. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Authors: Mnqeta, Zezethu
- Date: 2022-04-08
- Subjects: Cactus Biological control South Africa , Noxious weeds South Africa , Invasive plants Biological control South Africa , Insects as biological pest control agents South Africa , Cochineal insect South Africa , Mealybugs South Africa , Agricultural productivity South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294631 , vital:57239 , DOI 10.21504/10962/294631
- Description: Invasive alien cacti are prominent weeds that threaten indigenous biodiversity and have a negative impact on agricultural productivity in South Africa. These plants are problematic because they form dense thickets that reduce the carrying capacity of rangelands; restrict the movement of livestock and wildlife thus reducing access to shade and water sources; and are directly harmful to livestock, wildlife and people due to their sharp spines. Biological control is the most effective, affordable and environmentally friendly method to control invasive alien cacti and minimize their negative impacts. Cochineal insects (Dactylopius spp.: Dactylopiidae) and the gall-forming mealybug, Hypogeococcus sp. (Pseudococcidae) are used as biological control agents for cacti. The agents are however poor dispersers, so mass-rearing and augmentative releases are required in order to establish the agents at sites where they are needed. This study aimed to evaluate the mass-rearing and release efforts of cactus biological control in South Africa, quantify the impact of the biological control agents on cactus plant populations through long-term monitoring, and assess the benefits accrued due to the biological control agents through the perceptions of land-users. An assessment of the effectiveness of the release effort for cactus biological control agents was conducted by comparing where biological control agents have been released with the known distribution of the target weeds. Only 26% of the quarter degree squares that are known to be occupied by invasive alien cacti have had biological control agents released in them. This indicated that the mass-rearing and release efforts in South Africa are inadequate and should be increased, especially in areas where few releases have been made and many cacti are present, such as the Limpopo Province. The impact of the biological control agents on cactus plant populations was assessed by monitoring agent densities, target plant densities and target plant reproductive outputs before and after releases. Plant biomass and reproductive output were reduced by biological control agents for three of the target weeds that were assessed, while the duration of the study was too short to measure reductions for the fourth target weed. Benefits to land-users were then quantified through a questionnaire survey. Land-users perceived biological control as an effective management option, with 81% of the land-users reporting that there was less invasive alien cactus after releasing biological control agents on their land. Forty-nine percent of the land-users believed that the negative impacts of the cactus had been reduced and that they benefited more from their land since control was achieved. Since land-users were only interviewed within four years of the releases being conducted, it is expected that the percentage of land-users who gained benefits from biological control will increase in future. Ninety-seven percent of the land-users stated that the agents were safe and had not fed on any other plants or had any detrimental impacts. These perceptions indicated that land-users regarded biological control as a safe and effective method of controlling invasive alien cacti. This study confirms that biological control is an effective and safe way of controlling invasive alien Cactaceae. It is also the first to assess some of the benefits that land-users have accrued due to biological control of cactus weeds. It is however evident that a greater mass-rearing and release effort is required for South Africa to get the maximum benefits possible from the use of the biological control agents for cactus weeds that are available in the country. , Izityalo ze-cactus ezisuka kwamanye amazwe zilukhula olubalaseleyo, olwenza ingxaki kwintlobo ngeentlobo zezityalo nezilwanyana kwaye ezizityalo zinefuthe neziphumo ezingalunganga kwimveliso yezolimo eMzantsi Afrika. Ezi zizityalo ziyingxaki kuba zenza amatyholo ashinyeneyo athi anciphise umthamo wokusebenzisa umhlaba: zinqanda ukuhamba nogkukhululekileyo kwemfuyo nezilwanyana zasendle ngokwenza oko zingakwazi ukufikelela emthuzini xa kutshisa nakwimithombo yamanzi yokusela; zikwayiyo nengozi kwimfuyo, izilwanyana zasendle kunye nabantu ngenxa yamave abukhali afumaneka kwezizityalo. Ukulawula nokwehliza ubunzini nezinga lemigcipheko yezizityalo, kusetyenziswa indlela ekuthiwa yi-biological control. Lendlela yeyona ndlela isebenza ngokuphucukileyo, efikelelayo, nengenabungozi kokusingqongileyo. Izinambuzane ze- cochineal (i-Dactylopius spp.: Dactylopiidae) kunye ne-mealybug, i-Hypogeococcus sp. (Pseudococcidae) zisetyenziswe njengezixhobo ze-biological control ezinceda ukulawula ezizityalo ze-cactus zingafunekiyo. Ingxaki yazo ezizinambuzane zizixhobo ze-biological control zingentla kukuba azikwazi kuzisasaza ngokwazo ukuba zifikelele nakwizityalo ezikude ngoko ke ukukhuliswa nokukhutshwa ngobuninzi bazo kuyafuneka ukukhawulelana nalengxaki kunye nokwandisa amathuba wokuba zifikelele kuzozonke izityalo ze-cactus ekufuneka zizilawule. Olu phononongo lujolise ekuvavanyeni iinzame zokukhulisa ngobuninzi nokukhupha ezezinambuzane zizixhobo ze-bioloigical control zokulawula izityalo ze-cactus eMzantsi Afrika, ukujonga ubungakanani befuthe notshintsho elenziwa zezinambuzane zizixhobo ze-bioloigical control kwizityalo ze-cactus emva kwexesha elide lokuzijonga, kunye nokuvavanya inzuzo efunyenwe ngenxa yokulawula ezizityalo ze-cactus ngokwemibono yabasebenzisi bomhlaba. Uvavanyo lweenzame zokukhutshwa kwezixhobo zezixhobo zezinambuzane ze-bioloigical control kwizityalo ze-cactus lwenziwa ngokuthelekisa iindawo apho izixhobo zezinambuzane ze-biological control zikhutshwe khona kunye neendawo apho izityalo ze-cactus kwaziwayo ukuba ziyafumaneka khona. Yi-26% kuphela yesikwere sekota eyaziwayo ukuba kukhona izityalo ze-cactus nalapho kukhutshwe khona kwezinambuzane ezizixhobo ze-biological control. Oku kubonisa ukuba iinzame zokukhulisa nokukhutshwa kwezinambuzane ezizixhobo ze-biological control eMzantsi Afrika azanelanga kwaye kufuneka zandiswe, ngakumbi kwiindawo apho kukho ukhutsho olumbalwa olwenziweyo kunye nezityalo ze-cactus ezininzi ezifumaneka khona, njengePhondo laseLimpopo. Iimpembelelo yokukhutshwa kwezinambuzane ezizixhobo ze-biological control kwizityalo ze-cactus zavavanywa ngokujonga ubunizi bezinambuzane ezizixhobo ze-biological control, ukuxinana kwezityalo ze-cactus ekujoliswe kuzo kunye nemveliso yokuzala kwezityalo ze-cactus phambi nasemva kokuba kukhutshwe izinambuzane ezizixhobo ze-biological control. Ubungakanani bezityalo ze-cactus kunye nemveliso yokuzala ziye zacutheka emva kokukhutshwa kwezinambuzane ezizixhobo ze-biological control kwinzityalo ezintathu ze-cactus ebekujoliswe uvavanyo kuzo, ngelixa ixesha lophononongo lalifutshane kakhulu ukuvavanya unciphiso kwisityalo se-cactus sesine. Izibonelelo zabasebenzisi bomhlaba zaye zavavanywa kusetyenziswa uhlobo lwemibuzo. Abasebenzisi bomhlaba balubona ukusetyenziswa kwezinambuzane ezizixhobo ze-biological control njengendlela yolawulo olusebenzayo, yi81% yabasebenzisi bomhlaba echaze ukuba izityalo ze-cactus zecuthekile emva kokukhutshwa kwezinambuzane ezizixhobo ze-biological control emhlabeni wabo. Amashumi amane anesithoba eepesenti zabasebenzisi bomhlaba bakholelwa ukuba impembelelo ezingalunganga ze-cactus zincitshisiwe kwaye baxhamle kakhulu kumhlaba wabo okoko lwaphunyenzwa. Oludliwano-ndlebe belwenziwe kubasebenzisi bomhlaba kwisithuba seminyaka emine emva kokuba kukhutshwe izinambuzane ezizixhobo ze-biological control, kulindeleke ukuba ipesenti yabasebenzisi bomhlaba abathe bafumana izibonelelo kwi-biological control lonyuke kwixesha elizayo. Amashumi alithoba anesixhenxe ekhulwini abasebenzisi bomhlaba bachaze ukuba izinambuzane ezizixhobo ze-biological control zikhuselekile kwaye khange zidle kuzo naziphi na ezinye izityalo ezingezi eze-cactus ebekujoliswe kuzo okanye zineempembelelo eyingozi. Ezi mbono ziyabonisa ukuba abasebenzi bomhlaba bayithatha i-biological control njengendlela ekhuselekileyo nesebenzayo yokulawula izityalo ze-cactus zamanye amazwe. Olu phononongo luqinisekisa ukuba ulawulo olusebenzisa izinambuzane ezizixhobo ze-biological control yindlela esebenzayo nekhuselekileyo yokulawula iCactaceae yamanye amazwe. Ikwangolokuqala ukuvavanya ezinye zezibonelelo ezizuzwe ngabasebenzisi bomhlaba ngenxa ye-biological control yezityalo ze-cactus. Nangona kunjalo kucacile ukuba ukwandisa inzame zokukhulisa nokukhupha ngobuninzi izinambuzane ezizixhobo ze-biological control kuyafuneka ukuze uMzantsi Afrika ufumane izibonelelo eziphakamileyo enokubakho ngokusetyenziswa kwe zinambuzane ezizixhobo ze-biological control zokulawula ukhula lwe-cactus olukhoyo kweli lizwe. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
Singlet oxygen and optical limiting applications of BODIPYs and other molecular dyes
- Authors: May, Aviwe Khanya
- Date: 2022-04-08
- Subjects: Dyes and dyeing Chemistry , Phthalocyanines , Photochemotherapy , Active oxygen , Nonlinear optics , Time-dependent density functional theory , Photochemistry
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294618 , vital:57238 , DOI 10.21504/10962/294620
- Description: A series of structurally diverse novel and previously synthesized BODIPY core dyes are synthesized and characterized in this thesis. These BODIPYs were synthesized using 2-methylpyrrole, 2-ethylpyrrole, 2,4-dimethylpyrrole and 3-ethyl-2,4-dimethylpyrrole as the starting pyrroles. The combination of different pyrroles with the same aldehyde results in BODIPY core dyes that are structural analogues. These core dyes were used as precursors to synthesise halogenated BODIPYs and novel styrylBODIPY dyes, which were successfully characterized using FT-IR and 1H NMR spectroscopy. The halogenated BODIPY core dyes and the styrylBODIPY dyes were also characterized using MALDI-TOF mass spectrometry. The introduction of heavy atoms on the BODIPY core leads to a red shift of the main spectral. In the presence of styryl groups, the main spectral band red shifts to the far red end of the visible region. As expected, the halogenated BODIPY core dyes also had moderate singlet oxygen quantum yields. These halogenated core dyes were found to be suitable as photosensitizers as all the dyes reduced bacterial viability to below 50% during photodynamic antimicrobial chemotherapy (PACT) studies against Staphylococcus aureus. The structure-property relationships studied demonstrate that the presence of protons rather than methyls at the 1,7-positions or iodines at the 2,6-positions results in more favorable PACT activity. This is likely to be related to the greater ability of the meso-aryl to rotate into the plane of the dipyrromethene ligand and suggests that there should be a stronger focus on dyes of this type in future studies in this field. During nonlinear optical (NLO) studies, all the styrylBODIPYs exhibited favorable reverse saturable absorption (RSA) responses. In the absence of methyl groups at the 1,7-positions, the meso-aryl ring lies closer to the π-system of the BODIPY core, enhancing donor (D)–π–acceptor (A) properties and resulting in slightly enhanced optical limiting (OL) parameters. Additionally, there is no evidence that the introduction of heavy atoms at the 2,6-positions significantly enhances OL properties. In a similar manner, alkyl substituents at these positions also do not significantly enhance OL properties; this was studied for the first time using 15 with ethyl groups at the 2,6-positions. The combination of z-scan data and transient spectroscopy for 16 demonstrated that the main mechanism responsible for the NLO properties of nonhalogenated BODIPY dyes is one-photon absorption from the ground state followed by ESA in the singlet manifold. From the NLO studies of 25, OL parameters of 1,3,5-tristyrylBODIPY dyes were found to be similar in magnitude to properties of distyrylBODIPY dyes, but to have less favorable optical properties for OL applications. The OL properties of scandium phthalocyanines were assessed for the first time, since the Sc(III) ion, unusually for a first row transition metal ion, is known to readily form sandwich complexes. The presence of a Sc(III) ion does not significantly enhance the OL properties of phthalocyanines relative to those of rare earth metal ions that also form complexes of this type. Because BODIPYs and phthalocyanines typically absorb significantly in the visible region, transparent PBC polymer thin films of disilane-bridged compounds with minimal absorption in this region were studied and exhibited an excellent RSA response. These compounds may be useful in the design of OL materials that can protect the human eye. The optimized geometries and spectroscopic properties of selected BODIPYs were studied. As expected, the presence of bromine, iodine, ethyl and styryl groups at different positions of the BODIPY core leads to a narrowing of the HOMO–LUMO band gap, which results in a red-shift of the main spectral band. Partial atomic charges have also been calculated for some of the styrylBODIPY dyes studied for application in OL, and electrostatic potential energy maps were also visualized to better assess how the dipole moment of BODIPY dyes can be modulated since this can affect the OL properties. For all the BODIPYs studied, the electronegativity of the atoms present influences charge distribution on the BODIPY structure. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Authors: May, Aviwe Khanya
- Date: 2022-04-08
- Subjects: Dyes and dyeing Chemistry , Phthalocyanines , Photochemotherapy , Active oxygen , Nonlinear optics , Time-dependent density functional theory , Photochemistry
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294618 , vital:57238 , DOI 10.21504/10962/294620
- Description: A series of structurally diverse novel and previously synthesized BODIPY core dyes are synthesized and characterized in this thesis. These BODIPYs were synthesized using 2-methylpyrrole, 2-ethylpyrrole, 2,4-dimethylpyrrole and 3-ethyl-2,4-dimethylpyrrole as the starting pyrroles. The combination of different pyrroles with the same aldehyde results in BODIPY core dyes that are structural analogues. These core dyes were used as precursors to synthesise halogenated BODIPYs and novel styrylBODIPY dyes, which were successfully characterized using FT-IR and 1H NMR spectroscopy. The halogenated BODIPY core dyes and the styrylBODIPY dyes were also characterized using MALDI-TOF mass spectrometry. The introduction of heavy atoms on the BODIPY core leads to a red shift of the main spectral. In the presence of styryl groups, the main spectral band red shifts to the far red end of the visible region. As expected, the halogenated BODIPY core dyes also had moderate singlet oxygen quantum yields. These halogenated core dyes were found to be suitable as photosensitizers as all the dyes reduced bacterial viability to below 50% during photodynamic antimicrobial chemotherapy (PACT) studies against Staphylococcus aureus. The structure-property relationships studied demonstrate that the presence of protons rather than methyls at the 1,7-positions or iodines at the 2,6-positions results in more favorable PACT activity. This is likely to be related to the greater ability of the meso-aryl to rotate into the plane of the dipyrromethene ligand and suggests that there should be a stronger focus on dyes of this type in future studies in this field. During nonlinear optical (NLO) studies, all the styrylBODIPYs exhibited favorable reverse saturable absorption (RSA) responses. In the absence of methyl groups at the 1,7-positions, the meso-aryl ring lies closer to the π-system of the BODIPY core, enhancing donor (D)–π–acceptor (A) properties and resulting in slightly enhanced optical limiting (OL) parameters. Additionally, there is no evidence that the introduction of heavy atoms at the 2,6-positions significantly enhances OL properties. In a similar manner, alkyl substituents at these positions also do not significantly enhance OL properties; this was studied for the first time using 15 with ethyl groups at the 2,6-positions. The combination of z-scan data and transient spectroscopy for 16 demonstrated that the main mechanism responsible for the NLO properties of nonhalogenated BODIPY dyes is one-photon absorption from the ground state followed by ESA in the singlet manifold. From the NLO studies of 25, OL parameters of 1,3,5-tristyrylBODIPY dyes were found to be similar in magnitude to properties of distyrylBODIPY dyes, but to have less favorable optical properties for OL applications. The OL properties of scandium phthalocyanines were assessed for the first time, since the Sc(III) ion, unusually for a first row transition metal ion, is known to readily form sandwich complexes. The presence of a Sc(III) ion does not significantly enhance the OL properties of phthalocyanines relative to those of rare earth metal ions that also form complexes of this type. Because BODIPYs and phthalocyanines typically absorb significantly in the visible region, transparent PBC polymer thin films of disilane-bridged compounds with minimal absorption in this region were studied and exhibited an excellent RSA response. These compounds may be useful in the design of OL materials that can protect the human eye. The optimized geometries and spectroscopic properties of selected BODIPYs were studied. As expected, the presence of bromine, iodine, ethyl and styryl groups at different positions of the BODIPY core leads to a narrowing of the HOMO–LUMO band gap, which results in a red-shift of the main spectral band. Partial atomic charges have also been calculated for some of the styrylBODIPY dyes studied for application in OL, and electrostatic potential energy maps were also visualized to better assess how the dipole moment of BODIPY dyes can be modulated since this can affect the OL properties. For all the BODIPYs studied, the electronegativity of the atoms present influences charge distribution on the BODIPY structure. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
Synthesis and evaluation of the medicinal potential of novel 4-hydroxycoumarin derivatives
- Authors: Manyeruke, Meloddy Hlatini
- Date: 2022-04-08
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/164458 , vital:41120 , doi:10.21504/10962/164458
- Description: This research has focused on the synthesis and biological evaluation of a broad range of compounds characterised by the presence of the pharmacologically significant 4-hydroxycoumalin scaffold. The compounds were designed to contain additional pharmachophoric centres to enhance bioactivity and generate lead compounds with dualaction potential. The use of 4-hydroxycoumarin as the primary synthon enabled access to various series of 4-hydroxycoumarin conjugates, the reactive 3-position on the 4-hydroxycoumarin moiety being exploited for regioselective construction of the targeted compounds in several steps. Some of the reactants required in the construction of these compounds were specially synthesised and included propargyloxy benzaldehydes, benzyloxy benzaldehydes and 2,3-dihydroxysuccino-dihydride. Overall, eight different families of novel compounds were accessed, comprising conjugates of 4-hydroxycoumarin with bisethylidenesuccinohyrazide, trifluoroacetamide, amino, benzyloxyphenyl-iminoethyl, benzylidenehyrazinyl-thiazoyl, benzylidenehydrazonoethyl, propargyloxybenzylidenehydrazonoethyl and phenylacryloyl moieties using protocols that required minimal work-up and purification. The eighty novel compounds synthesised in the study were fully characterised using HMRS and advanced NMR techniques. Cytotoxicity, HIV-1 IN and PR inhibitory, and antitrypanosomal, antimalarial and anti-Mtb assays were conducted on the synthesised coumarin derivatives. Several compounds exhibited activity against HIV-1 IN, the most potent being a bis-ethylidenesuccinohyrazide with an IC50 value of 3.5 μM. Various compounds exhibited anti-malarial activity (% pLDH viability in the range 62-77%), anti-trypanosomal activity (the most potent with an IC50 = 0.9 μM against T.b. brucei) and a measure of anti-Mtb activity. Apart from two chalconyl derivatives, none of the synthesised compounds exhibited significant cytotoxicity. Conflicting results were obtained from the in silico docking studies; in some cases supporting the observed in vitro assay data while, in others, exhibiting no correlation. , Thesis (PhD) -- Faculty of Science, Chemistry, 2020
- Full Text:
- Authors: Manyeruke, Meloddy Hlatini
- Date: 2022-04-08
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/164458 , vital:41120 , doi:10.21504/10962/164458
- Description: This research has focused on the synthesis and biological evaluation of a broad range of compounds characterised by the presence of the pharmacologically significant 4-hydroxycoumalin scaffold. The compounds were designed to contain additional pharmachophoric centres to enhance bioactivity and generate lead compounds with dualaction potential. The use of 4-hydroxycoumarin as the primary synthon enabled access to various series of 4-hydroxycoumarin conjugates, the reactive 3-position on the 4-hydroxycoumarin moiety being exploited for regioselective construction of the targeted compounds in several steps. Some of the reactants required in the construction of these compounds were specially synthesised and included propargyloxy benzaldehydes, benzyloxy benzaldehydes and 2,3-dihydroxysuccino-dihydride. Overall, eight different families of novel compounds were accessed, comprising conjugates of 4-hydroxycoumarin with bisethylidenesuccinohyrazide, trifluoroacetamide, amino, benzyloxyphenyl-iminoethyl, benzylidenehyrazinyl-thiazoyl, benzylidenehydrazonoethyl, propargyloxybenzylidenehydrazonoethyl and phenylacryloyl moieties using protocols that required minimal work-up and purification. The eighty novel compounds synthesised in the study were fully characterised using HMRS and advanced NMR techniques. Cytotoxicity, HIV-1 IN and PR inhibitory, and antitrypanosomal, antimalarial and anti-Mtb assays were conducted on the synthesised coumarin derivatives. Several compounds exhibited activity against HIV-1 IN, the most potent being a bis-ethylidenesuccinohyrazide with an IC50 value of 3.5 μM. Various compounds exhibited anti-malarial activity (% pLDH viability in the range 62-77%), anti-trypanosomal activity (the most potent with an IC50 = 0.9 μM against T.b. brucei) and a measure of anti-Mtb activity. Apart from two chalconyl derivatives, none of the synthesised compounds exhibited significant cytotoxicity. Conflicting results were obtained from the in silico docking studies; in some cases supporting the observed in vitro assay data while, in others, exhibiting no correlation. , Thesis (PhD) -- Faculty of Science, Chemistry, 2020
- Full Text:
The role of angling-guides in promoting pro-environmental catch-and-release attitudes and behaviours in the recreational angling community
- Authors: Farthing, Matthew William
- Date: 2022-04-08
- Subjects: Fishing , Fishing Catch effort , Fishing guides , Fishers , Human behavior , Role models
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294583 , vital:57235 , DOI 10.21504/10962/294585
- Description: Angling-guides are respected as opinion leaders of the recreational angling community, but nothing is known of their influence on angler behaviour. Given their social-standing, angling-guides may be perceived as role-models by angling-clients – thereby promoting the adoption of best and/or poor catch-and-release (C&R) practices, depending on their individual knowledge, attitudes and behaviour. It is critical to understand their potential influence, their knowledge and their behaviours to inform effective intervention strategies which could exploit their extensive networking potential. The aim of this thesis was to better understand the potential utility of angling-guides in efforts to improve angler behaviour. Firstly, this was done by investigating whether angling-guides are perceived as role-models by angling-clients (Chapter 2). Secondly, it was done by assessing the current level of knowledge, attitudes and behaviours of angling-guides from around the world (Chapter 3). Thirdly, it was done by exploring the relationship between angling-guide knowledge, attitudes, intentions and actual behaviour in a case-study of guided-angling trips (Chapter 4). Lastly, it was done by exploring intervention frameworks and incorporating insights into potential strategies for promoting pro-environmental angling behaviours to angling-guides (Chapter 5). To understand if angling-guides are perceived as role-models by the recreational angling community (Chapter 2), a digital survey was designed to assess previous angling-clients’ attitudes towards angling-guides serving the three role-model functions proposed in the Motivational Theory of Role-Modelling, namely as Behavioural models, Representations of the Possible and Inspiration. Of the 492 angling-clients (27 countries), most agreed that angling-guides were competent, skilled, and worth emulating (91.1%), suggesting they are perceived as Behavioural Models. Less agreed that angling-guides were Inspirational or Representations of the Possible (54.8%), suggesting they are less likely to motivate anglers to adopt and/or pursue new goals. As Behavioural Models, angling-guide C&R practices are likely to be emulated, which is of both utility and concern to managers. As angling-guides are likely to be emulated, a digital survey was designed to assess their knowledge, attitudes and behaviours (particularly C&R best-practices) (Chapter 3). Of the 342 angling-guides (47 countries), few had accredited training (9.4%). However, most were deemed “knowledgeable of best-practices” (69.0%), but pervasive misconceptions of key C&R best-practices were observed. Attitudes towards best-practices were generally pro-environmental, and those deemed knowledgeable had significantly more pro-environmental attitudes (p = 0.003). Most angling-guides had pro-environmental attitudes towards their environmental responsibilities (87.1 - 89.5%), but these broad attitudes cannot predict specific pro-environmental behaviours during guided-angling trips where angler satisfaction is often at odds with best-practice. Angling-client satisfaction has important financial implications for angling-guides, and even those with pro-environmental intentions may struggle to adhere to C&R best-practices with inherent sacrifices for the angling-client’s enjoyment. Observation of behaviour in context is critical for understanding the behaviour to be changed. To explore the relationship between angling-guide knowledge, intentions and actual behaviour (Chapter 4), five angling-guides were observed (and filmed) interacting with groups of angling-clients during their guided-angling trips over a 30 day period. Five angling behaviours of interest were identified, and a survey focussed on these behaviours was disseminated (18 months later) to the five angling-guides previously observed to assess their knowledge, attitudes, reported behaviours and perceptions of the norm. Generally the subjects’ reported behaviours aligned well with their knowledge of best-practice, but their actual behaviour was not well aligned (24.4%). Instead, their actual behaviour aligned better with their perceptions of the norm (80.9%), which was generally a “worse” practice than what they reported. Angling-guides appeared to favour client-satisfaction over pro-environmental behaviour. Gaps between angling-guides’ knowledge of best-practice and their actual behaviour indicate that there may be obscure and complex barriers to pro-environmental angling-guide behaviour. Many barriers are seemingly impossible to overcome, such as economic limitations and financial disincentives. These barriers may limit the efficacy of traditional knowledge-attitude-behaviour (KAB) change interventions. The strong alignment of angling-guide behaviour with social norms, and the strong community orientation of recreational angling suggests that the Community-Based Social Marketing (CBSM) approach may be a more effective framework for interventions that aim to promote pro-environmental catch-and-release behaviours at angling-guide level. The CBSM approach allows interventionists to leverage a larger suite of cognitive biases than KAB approaches, provided that sufficient understanding of the context, barriers and benefits for a given segment of the angling-guide community (likely defined by style-of-participation) are obtained. Furthermore, the success of the CBSM approach will depend on the ability of interventionists to effectively recruit and incentivise disjunct and isolated communities of angling-guides to participate in training and workshops in order to achieve the important in-person contact on which the CBSM approach depends. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Authors: Farthing, Matthew William
- Date: 2022-04-08
- Subjects: Fishing , Fishing Catch effort , Fishing guides , Fishers , Human behavior , Role models
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294583 , vital:57235 , DOI 10.21504/10962/294585
- Description: Angling-guides are respected as opinion leaders of the recreational angling community, but nothing is known of their influence on angler behaviour. Given their social-standing, angling-guides may be perceived as role-models by angling-clients – thereby promoting the adoption of best and/or poor catch-and-release (C&R) practices, depending on their individual knowledge, attitudes and behaviour. It is critical to understand their potential influence, their knowledge and their behaviours to inform effective intervention strategies which could exploit their extensive networking potential. The aim of this thesis was to better understand the potential utility of angling-guides in efforts to improve angler behaviour. Firstly, this was done by investigating whether angling-guides are perceived as role-models by angling-clients (Chapter 2). Secondly, it was done by assessing the current level of knowledge, attitudes and behaviours of angling-guides from around the world (Chapter 3). Thirdly, it was done by exploring the relationship between angling-guide knowledge, attitudes, intentions and actual behaviour in a case-study of guided-angling trips (Chapter 4). Lastly, it was done by exploring intervention frameworks and incorporating insights into potential strategies for promoting pro-environmental angling behaviours to angling-guides (Chapter 5). To understand if angling-guides are perceived as role-models by the recreational angling community (Chapter 2), a digital survey was designed to assess previous angling-clients’ attitudes towards angling-guides serving the three role-model functions proposed in the Motivational Theory of Role-Modelling, namely as Behavioural models, Representations of the Possible and Inspiration. Of the 492 angling-clients (27 countries), most agreed that angling-guides were competent, skilled, and worth emulating (91.1%), suggesting they are perceived as Behavioural Models. Less agreed that angling-guides were Inspirational or Representations of the Possible (54.8%), suggesting they are less likely to motivate anglers to adopt and/or pursue new goals. As Behavioural Models, angling-guide C&R practices are likely to be emulated, which is of both utility and concern to managers. As angling-guides are likely to be emulated, a digital survey was designed to assess their knowledge, attitudes and behaviours (particularly C&R best-practices) (Chapter 3). Of the 342 angling-guides (47 countries), few had accredited training (9.4%). However, most were deemed “knowledgeable of best-practices” (69.0%), but pervasive misconceptions of key C&R best-practices were observed. Attitudes towards best-practices were generally pro-environmental, and those deemed knowledgeable had significantly more pro-environmental attitudes (p = 0.003). Most angling-guides had pro-environmental attitudes towards their environmental responsibilities (87.1 - 89.5%), but these broad attitudes cannot predict specific pro-environmental behaviours during guided-angling trips where angler satisfaction is often at odds with best-practice. Angling-client satisfaction has important financial implications for angling-guides, and even those with pro-environmental intentions may struggle to adhere to C&R best-practices with inherent sacrifices for the angling-client’s enjoyment. Observation of behaviour in context is critical for understanding the behaviour to be changed. To explore the relationship between angling-guide knowledge, intentions and actual behaviour (Chapter 4), five angling-guides were observed (and filmed) interacting with groups of angling-clients during their guided-angling trips over a 30 day period. Five angling behaviours of interest were identified, and a survey focussed on these behaviours was disseminated (18 months later) to the five angling-guides previously observed to assess their knowledge, attitudes, reported behaviours and perceptions of the norm. Generally the subjects’ reported behaviours aligned well with their knowledge of best-practice, but their actual behaviour was not well aligned (24.4%). Instead, their actual behaviour aligned better with their perceptions of the norm (80.9%), which was generally a “worse” practice than what they reported. Angling-guides appeared to favour client-satisfaction over pro-environmental behaviour. Gaps between angling-guides’ knowledge of best-practice and their actual behaviour indicate that there may be obscure and complex barriers to pro-environmental angling-guide behaviour. Many barriers are seemingly impossible to overcome, such as economic limitations and financial disincentives. These barriers may limit the efficacy of traditional knowledge-attitude-behaviour (KAB) change interventions. The strong alignment of angling-guide behaviour with social norms, and the strong community orientation of recreational angling suggests that the Community-Based Social Marketing (CBSM) approach may be a more effective framework for interventions that aim to promote pro-environmental catch-and-release behaviours at angling-guide level. The CBSM approach allows interventionists to leverage a larger suite of cognitive biases than KAB approaches, provided that sufficient understanding of the context, barriers and benefits for a given segment of the angling-guide community (likely defined by style-of-participation) are obtained. Furthermore, the success of the CBSM approach will depend on the ability of interventionists to effectively recruit and incentivise disjunct and isolated communities of angling-guides to participate in training and workshops in order to achieve the important in-person contact on which the CBSM approach depends. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
The transformative potential of intersecting arts-based inquiry and environmental learning in urban South Africa: a focus on socio-ecological water pedagogies
- Authors: James, Anna Katharine
- Date: 2022-04-08
- Subjects: Environmental education South Africa , Water conservation Study and teaching South Africa , Art in environmental education South Africa , Social learning South Africa , Educational sociology South Africa , Water-supply Social aspects South Africa , Critical realism , Socio-ecological education
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/290660 , vital:56772 , DOI 10.21504/10962/290660
- Description: In this study I explore and explain transformative potential in arts-based environmental learning with a focus on water pedagogy. The study took place over a period of four years, where approximately 40 school pupils between the ages of 10 and 17 years-old were engaged in participatory arts-based inquiries into water located across unequal neighbourhoods in Cape Town, South Africa. Educators, school learners, citizens and decision-makers hold different historical, cultural, political and spiritual perspectives on water. These play a role in shaping what is termed in this research the ‘hydro-social cycle’. Yet, due to dominant ideas of what counts as knowing and truth, educators in educational settings struggle to account for the complexity of water, limiting educational encounters to a partial knowing leading mostly to limited unimaginative framings of problems and solutions. My focus on transformative potential in learning is derived from a concern for how environmental education encounters and the sense-making they enable, are infused by socio-economic, political, and historical elements, specifically colonialism, capitalism, and white supremacist racism. The connections between the multiple layers of capitalist crisis and the ever-urgent environmental crisis are not adequately made in mainstream forms of water education. The research explores how arts-based pedagogy could enable a productive meeting of critical environmental education with ecological literacies. Within this positioning, transformative potential considers how educational engagements position questions about water within the social life of participants/learners and inform learning that leads to fuller and more nuanced greater knowledge. Theoretically, I work with an interrogation of critical education theory, underlaboured by critical realism which enabled me to rigorously consider how claims to knowing are shaped by their accompanying assumptions of what is real. Drawing on recent debates in critical education theory, I resist the notion of critique as ideology and engage instead in the craftsmanship of contextual and responsive inquiry practice. This has enabled me to articulate processes and relationships in water education encounters with meaningful understandings of the effects of simultaneous crises rooted in racial capitalism and environmental crisis. My methodological approach is arts-based educational research with a directive to reflect upon educational encounters in an integrated way. It includes two parts informing the facilitation and analysis of open-ended learning processes. One component was arts-based inquiry practice developed for exploring complexity, drawing on the thinking of Norris (2009, 2011) and Finley (2016, 2017). The second part holds reflective space for these encounters guided by the practice of pedagogical narration inspired by the Reggio Amelia approach, demonstrated by Pacini-Ketchabaw, Nxumalo, Kocher, Elliot and Sanchez (2014). Clarifying the intellectual work of a responsive educator-researcher, pedagogical narration brings multiple theoretical lenses into conversation with emergent dimensions of educational process. In practice, in order to transgress the dominance of colonial white supremacist knowledge frames of water, I needed to be curious, to be confounded, to expect the unexpected in the educational encounters with participants and this mirroring of practice was emulated by the participants as they followed their own questions about water in Mzansi (South Africa). In our work together we came up against assumptions we had previously not questioned as individuals. Together we explored the implications of this by, for example, questioning who is responsible for saving water. These explorations required bringing together science knowledge and everyday knowledge at multiple scales: the household, catchment, government and global. It required us to be critical of how language and images are mobilized in public communication and school curriculums; for example, representations of water are infused with history and power in a way that impacts how we know and teach about water. The transformative potential of this pedagogical space is generated through acts of creative expression which are seen as acts of absenting absence, for example exhibiting through play how water use in the household interconnects with gender and age relationships. As such, creative expression through multiple mediums or more-than-text enables a deeper understanding of water as well as openings for interdisciplinary engagement with learning about water. My research found that in bringing together the contributions of critical education and environmental education in practice, two shifts are needed: environmental educators need to view ecological literacy as inseparable from the social and political. The knowledge that is shared about water in the classroom has social and political implications. On the other hand, critical educators need to better locate justice concerns in the material and ecological world at scale. Arts-based inquiry, as a kind of scaffolding for pedagogical process, has the potential to enable these shifts by opening up fixed analytical frames. Making these shifts requires a reflective practice on the part of the educator to navigate the inherited blind spots in environmental learning and critical education, such as dualities. One way to do this is for the educator to identify absences, as articulated in the Critical Realist tradition, and consider how these absences might be absented. This differs from a simplistic process of critique in the possibilities it opens up for collaboration between different schools of thought rather than further polarisation and alienation between educators and knowledge keepers on social ecologies. These insights have relevance for many sites of environmental education practice, such as natural science lecturers, school teachers or community activists. It is knowledge-learning work emergent from and responsive to complex ecological crisis, which requires everyone to rethink and open up to new ways of being, seeing and doing around these issues. The transformative potential of this work is that the thinking and transforming at all scales can be catalysed and grounded through the arts based educational encounters with the participants. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Authors: James, Anna Katharine
- Date: 2022-04-08
- Subjects: Environmental education South Africa , Water conservation Study and teaching South Africa , Art in environmental education South Africa , Social learning South Africa , Educational sociology South Africa , Water-supply Social aspects South Africa , Critical realism , Socio-ecological education
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/290660 , vital:56772 , DOI 10.21504/10962/290660
- Description: In this study I explore and explain transformative potential in arts-based environmental learning with a focus on water pedagogy. The study took place over a period of four years, where approximately 40 school pupils between the ages of 10 and 17 years-old were engaged in participatory arts-based inquiries into water located across unequal neighbourhoods in Cape Town, South Africa. Educators, school learners, citizens and decision-makers hold different historical, cultural, political and spiritual perspectives on water. These play a role in shaping what is termed in this research the ‘hydro-social cycle’. Yet, due to dominant ideas of what counts as knowing and truth, educators in educational settings struggle to account for the complexity of water, limiting educational encounters to a partial knowing leading mostly to limited unimaginative framings of problems and solutions. My focus on transformative potential in learning is derived from a concern for how environmental education encounters and the sense-making they enable, are infused by socio-economic, political, and historical elements, specifically colonialism, capitalism, and white supremacist racism. The connections between the multiple layers of capitalist crisis and the ever-urgent environmental crisis are not adequately made in mainstream forms of water education. The research explores how arts-based pedagogy could enable a productive meeting of critical environmental education with ecological literacies. Within this positioning, transformative potential considers how educational engagements position questions about water within the social life of participants/learners and inform learning that leads to fuller and more nuanced greater knowledge. Theoretically, I work with an interrogation of critical education theory, underlaboured by critical realism which enabled me to rigorously consider how claims to knowing are shaped by their accompanying assumptions of what is real. Drawing on recent debates in critical education theory, I resist the notion of critique as ideology and engage instead in the craftsmanship of contextual and responsive inquiry practice. This has enabled me to articulate processes and relationships in water education encounters with meaningful understandings of the effects of simultaneous crises rooted in racial capitalism and environmental crisis. My methodological approach is arts-based educational research with a directive to reflect upon educational encounters in an integrated way. It includes two parts informing the facilitation and analysis of open-ended learning processes. One component was arts-based inquiry practice developed for exploring complexity, drawing on the thinking of Norris (2009, 2011) and Finley (2016, 2017). The second part holds reflective space for these encounters guided by the practice of pedagogical narration inspired by the Reggio Amelia approach, demonstrated by Pacini-Ketchabaw, Nxumalo, Kocher, Elliot and Sanchez (2014). Clarifying the intellectual work of a responsive educator-researcher, pedagogical narration brings multiple theoretical lenses into conversation with emergent dimensions of educational process. In practice, in order to transgress the dominance of colonial white supremacist knowledge frames of water, I needed to be curious, to be confounded, to expect the unexpected in the educational encounters with participants and this mirroring of practice was emulated by the participants as they followed their own questions about water in Mzansi (South Africa). In our work together we came up against assumptions we had previously not questioned as individuals. Together we explored the implications of this by, for example, questioning who is responsible for saving water. These explorations required bringing together science knowledge and everyday knowledge at multiple scales: the household, catchment, government and global. It required us to be critical of how language and images are mobilized in public communication and school curriculums; for example, representations of water are infused with history and power in a way that impacts how we know and teach about water. The transformative potential of this pedagogical space is generated through acts of creative expression which are seen as acts of absenting absence, for example exhibiting through play how water use in the household interconnects with gender and age relationships. As such, creative expression through multiple mediums or more-than-text enables a deeper understanding of water as well as openings for interdisciplinary engagement with learning about water. My research found that in bringing together the contributions of critical education and environmental education in practice, two shifts are needed: environmental educators need to view ecological literacy as inseparable from the social and political. The knowledge that is shared about water in the classroom has social and political implications. On the other hand, critical educators need to better locate justice concerns in the material and ecological world at scale. Arts-based inquiry, as a kind of scaffolding for pedagogical process, has the potential to enable these shifts by opening up fixed analytical frames. Making these shifts requires a reflective practice on the part of the educator to navigate the inherited blind spots in environmental learning and critical education, such as dualities. One way to do this is for the educator to identify absences, as articulated in the Critical Realist tradition, and consider how these absences might be absented. This differs from a simplistic process of critique in the possibilities it opens up for collaboration between different schools of thought rather than further polarisation and alienation between educators and knowledge keepers on social ecologies. These insights have relevance for many sites of environmental education practice, such as natural science lecturers, school teachers or community activists. It is knowledge-learning work emergent from and responsive to complex ecological crisis, which requires everyone to rethink and open up to new ways of being, seeing and doing around these issues. The transformative potential of this work is that the thinking and transforming at all scales can be catalysed and grounded through the arts based educational encounters with the participants. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text: